The preparation of thin zinc air battery. The cell, 1 cm2 area x ca. 460 μm thick, possesses limiting current of 27 mA, maximum power output of 31 mW, and vlumetric energy
density of 924 Wh l-1, rated at 20 mA. A bipolar design
markedly improves the cell performance. The cell, 1 cm2
area x ca. 920 μm thick, possesses limiting current
of 95 mA, maximum power output of 107 mW, and
volumetric energy density of 1189 Wh l-1.
Effect of morphology on the photoelectrochemical performance of nanostructure...Pawan Kumar
This document discusses the effect of morphology on the photoelectrochemical performance of nanostructured Cu2O photocathodes. It summarizes that:
1) Different deposition methods including electroreduction, anodization, thermal oxidation, and chemical oxidation were used to deposit planar and 1D nanostructured Cu2O thin films on copper foil with varying morphologies.
2) Mesoscopic and planar Cu2O morphologies exhibited large differences in carrier density and charge transfer resistance, but these differences did not strongly influence their photoelectrochemical performance.
3) Planar Cu2O deposited via electroreduction provided the highest photocurrent density of 5.0 mA cm−2 at 0 V vs RHE,
X-Ray Diffraction Analysis of the Microscopies of Some Corrosion-Protective B...IJMER
The document analyzes the microstructures of corrosion protective coatings produced from bitumens harvested in Nigeria using X-ray diffraction. The coatings were produced by bath dipping steel specimens in heated bitumen at 230°C. XRD analysis found the coatings contained different mineral phases constituting 3.75-4.847% of the coating. Coatings from the same bitumen source (KPB) varied in mineral composition, indicating microstructural variations. The KPB coatings exhibited the highest corrosion protection while coatings from Ondo S-A bitumen exhibited the lowest. The results provide information to improve bitumen composition and coating methods for better performance.
Carbon nanotubes properties and applicationsAMIYA JANA
This document discusses carbon nanotubes and their history and discovery. It begins by providing background on carbon nanotubes, describing their cylindrical nanostructure and how they are made by rolling graphene sheets into cylinders. It then discusses the history and discovery of carbon nanotubes, including the discovery of fullerenes in 1985 and carbon nanotubes themselves in 1991 by Sumio Iijima. The document concludes by classifying the two main types of carbon nanotubes as single-walled and multi-walled nanotubes.
POLYMER MODIFICATION WITH CARBON NANOTUBESArjun K Gopi
This document discusses the modification of polymers with carbon nanotubes to produce polymer-carbon nanotube composites. It first introduces different types of carbon nanotubes and discusses challenges in dispersing carbon nanotubes in polymer matrices due to their low compatibility. It then covers various methods used to functionalize carbon nanotubes and polymers to improve their interaction and dispersion, including covalent and non-covalent attachment of polymers to carbon nanotube surfaces. The document also discusses applications of these composites, particularly for reinforcing polymers like polyethylene, and their potential use in radiation shielding and resistant materials.
Effect of morphology on the photoelectrochemical performance of nanostructure...Pawan Kumar
This document discusses the effect of morphology on the photoelectrochemical performance of nanostructured Cu2O photocathodes. It summarizes that:
1) Different deposition methods including electroreduction, anodization, thermal oxidation, and chemical oxidation were used to deposit planar and 1D nanostructured Cu2O thin films on copper foil with varying morphologies.
2) Mesoscopic and planar Cu2O morphologies exhibited large differences in carrier density and charge transfer resistance, but these differences did not strongly influence their photoelectrochemical performance.
3) Planar Cu2O deposited via electroreduction provided the highest photocurrent density of 5.0 mA cm−2 at 0 V vs RHE,
X-Ray Diffraction Analysis of the Microscopies of Some Corrosion-Protective B...IJMER
The document analyzes the microstructures of corrosion protective coatings produced from bitumens harvested in Nigeria using X-ray diffraction. The coatings were produced by bath dipping steel specimens in heated bitumen at 230°C. XRD analysis found the coatings contained different mineral phases constituting 3.75-4.847% of the coating. Coatings from the same bitumen source (KPB) varied in mineral composition, indicating microstructural variations. The KPB coatings exhibited the highest corrosion protection while coatings from Ondo S-A bitumen exhibited the lowest. The results provide information to improve bitumen composition and coating methods for better performance.
Carbon nanotubes properties and applicationsAMIYA JANA
This document discusses carbon nanotubes and their history and discovery. It begins by providing background on carbon nanotubes, describing their cylindrical nanostructure and how they are made by rolling graphene sheets into cylinders. It then discusses the history and discovery of carbon nanotubes, including the discovery of fullerenes in 1985 and carbon nanotubes themselves in 1991 by Sumio Iijima. The document concludes by classifying the two main types of carbon nanotubes as single-walled and multi-walled nanotubes.
POLYMER MODIFICATION WITH CARBON NANOTUBESArjun K Gopi
This document discusses the modification of polymers with carbon nanotubes to produce polymer-carbon nanotube composites. It first introduces different types of carbon nanotubes and discusses challenges in dispersing carbon nanotubes in polymer matrices due to their low compatibility. It then covers various methods used to functionalize carbon nanotubes and polymers to improve their interaction and dispersion, including covalent and non-covalent attachment of polymers to carbon nanotube surfaces. The document also discusses applications of these composites, particularly for reinforcing polymers like polyethylene, and their potential use in radiation shielding and resistant materials.
Nano ceramics and composites have a variety of applications due to their unique properties at the nanoscale. Nanoceramics are ceramics composed of nanoparticles produced using methods like sol-gel processing. They can be used in applications like medical technology and energy storage due to properties like strength and flexibility. Nanocomposites contain one material with at least one dimension below 100nm. Polymer nanocomposites improve mechanical properties and transparency through high surface area reinforcement. Common preparation methods include sol-gel and electrospinning. Potential applications include lightweight materials, sensors, and abrasion resistance.
Enhancing Electrochemical Performance of V2O5 Thin Film by using Ultrasonic W...iosrjce
Ultrasonic weltering was used to enhance the electrochemical performance of V2O5 thin films deposited on stainless steel substrates for use as electrodes in supercapacitors. Structural, morphological, physical and electrochemical characterization showed that ultrasonic weltering resulted in more crystalline and porous films with increased specific surface area. This led to improved ion transport and a 19% increase in specific capacitance from 333 F/g to 397 F/g. Energy density also increased from 2.44 Wh/kg to 2.97 Wh/kg, while power density rose from 3.11 kW/kg to 3.52 kW/kg. Therefore, ultrasonic weltering produced structural and morphological changes that enhanced the supercapacitive properties
Synthesis and characterization of nanocompositessowmya sankaran
This document defines and discusses different types of nanocomposites. It begins by defining nanotechnology and some unique properties at the nanoscale. It then discusses different types of nanomaterials that can be used in nanocomposites like nanoparticles, nanotubes, and nanorods. The document outlines three main types of nanocomposites - metal matrix, ceramic matrix, and polymer matrix - and provides examples and processing methods for each type. It concludes by discussing several applications of nanocomposites in areas like food packaging, environmental protection, aerospace, automotive, and batteries.
This document discusses X-ray diffraction (XRD) spectroscopy and provides examples of applying XRD principles to characterize different materials. It describes the basic principles of how XRD works using Bragg's law and Miller indices to identify crystal planes. Examples are given for characterizing silver nanoparticles, graphite, graphene oxide, and zinc oxide nanoparticles using XRD, including estimating particle sizes from XRD peak widths and identifying functional groups from infrared spectroscopy. References are also provided for further reading.
This document discusses Molybdenum disulfide (MoS2) as a new material for biosensors. MoS2 is a 2D semiconductor with tunable band structure and high carrier mobility. It can be synthesized through mechanical exfoliation, solution methods, and chemical vapor deposition. MoS2 has applications in sensors, memory, photovoltaics due to its direct bandgap and flexibility. Functionalized MoS2 can be used to develop electrode-based and optical biosensors to detect molecules like glucose and dopamine. While MoS2 shows promise for flexible electronics and biosensing, further studies are needed to optimize device performance and compatibility with plastic substrates.
Electrochemical Supercapacitive Performance of Sprayed Co3O4 ElectrodesIJERA Editor
Nanocrystalline cobalt oxide (Co3O4) thin film electrodes were fabricated by spray pyrolysis method on conducting fluorine doped tin oxide (FTO) substrates using ammonia complexed with cobalt chloride (CoCl2. 6H2O) solution. The structural and morphological properties of Co3O4electrodes were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM).The surface morphology study showed the film formation of porous surface with clusters. The electrochemical supercapacitive properties ofCo3O4 electrodes were evaluated using cyclic voltammetry and galvanostatic charge-discharge method. The Co3O4electrodes showed maximum specific capacitance of 168 F/g in 1 M aqueous KOH electrolyte at the scan rate of 20 mV/s. The maximum specific energy and specific power of the cell are 2.2Wh/kg and 0.23 kW/kg, respectively.
Patent Landscape Report on “Dielectric Polymer Nanocomposites” by DexPatentCaroline Charumathy
The Dielectric Property of Polymer Nanocomposite is an emerging and fast moving concept in electrical insulation. It is used in wide range of applications including Energy storage devices, Thin films, Semiconductor devices and Electromagnetic shielding or as radar- absorbent materials (RAMs). This landscape report will help in understanding the developments relating to preparation and use of Dielectric Polymer Nanocomposites
To get in-depth analysis of specific technology areas and the competitive patent landscape similar to this, contact us.
Nanocomposites have various applications in aircraft construction and jet engines due to their beneficial properties. They can be used as strengthening elements in aircraft structures or as skin for honeycomb structures on wings and fuselages. Carbon-carbon composites with carbon fiber reinforcement and polymer or carbon matrices are used for high temperature components. Nanocomposites with zirconia matrices provide thermal protection for turboengine parts. Nanocoatings made from ceramics with nano-particles can increase adhesion, decrease oxygen permeability, and improve resistance to thermal shock for thermal barrier coatings on jet engines.
Fabrication and characterization of nickelijoejournal
This paper shows that nickel nanowires of length 11μm and diameters 800 and 15nm were grown within
the pores of nuclear track polycarbonate membrane by electrodepositing nickel. Surface morphology and
crystallographic structure of the deposited nanowires was investigated using SEM, TEM and XRD
respectively. It is found that low current density gives good result, while high current density leads to the
formation of curled nanowires. Fabricated nanowires were further investigated for electrical properties
and found that nanowires obey ohm’s law. Through structural characterization it has been observed that
the fabricated nanowires posses FCC lattice structure.
Carbon nanotubes with special application to the cnt reoinforced glass and glassRahul Dubey
The document discusses carbon nanotubes (CNTs), their properties, production methods, and applications. Specifically, it focuses on using CNTs to reinforce glass and glass-ceramic matrix composites. The key points are:
1) CNTs have excellent mechanical and thermal properties that make them promising reinforcements. Their production via electric arc discharge, laser ablation, or chemical vapor deposition controls their quality.
2) Manufacturing CNT-reinforced glass/glass-ceramic composites requires well-dispersed CNTs, strong interfaces, and consolidation to high densities using techniques like spark plasma sintering.
3) Preliminary results show the composites have improved hardness, elastic modulus
The document experimentally investigates aluminum alloy with multi-walled carbon nanotube (MWCNT) composite to increase mechanical properties using stir casting method. Aluminum 6061 alloy was used as the matrix and MWCNTs were added as reinforcement at 1 wt%. Samples were prepared via stir casting and characterized through optical microscopy, SEM, hardness testing, and tensile testing. Results showed that the MWCNT composite had higher hardness and tensile strength than the unreinforced aluminum alloy. Specifically, the 1 wt% MWCNT composite demonstrated improved proof stress, ultimate tensile strength, and hardness compared to the unreinforced alloy, indicating the MWCNTs successfully increased the mechanical properties of the aluminum matrix.
This document discusses nanostructures, their synthesis, and surface modification techniques. It defines nanostructures as having at least one dimension between 1-100 nm. Nanostructures are classified based on dimensionality as 0D, 1D, 2D, and 3D. Common synthesis methods include physical vapor deposition, chemical vapor deposition, and thermal spraying. Surface modification is done to change properties like reactivity, roughness, and corrosion protection. Common modification techniques are thermal spraying, PVD, and CVD.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
A study of Carbon Nanotubes as Smart Reinforcemants for Glass/ Glass ceramic ...Rahul Dubey
This document presents a study on carbon nanotubes (CNTs) as reinforcements for glass and glass ceramic matrix composites. CNTs have excellent mechanical and physical properties due to their nano-scale size. The document discusses methods of CNT production, their properties, and manufacturing of CNT-reinforced glass composites. Incorporating CNTs improves the mechanical, electrical and thermal properties of the brittle glass matrix. Potential applications include structural components, heat sinks, and thermal barrier coatings. However, more research is still needed to fully understand CNT reinforcement effects and address issues like mass production costs and health impacts.
Light Transmitting Concrete or Transparent ConcreteSahla Fathima
Light transmitting concrete is a novel building material made of cement, mortar, and optical fibers. Optical fibers are drilled through the cement and mortar to guide light and utilize sunlight as a light source to reduce power consumption for illumination. The optical fibers compose only 4% of the concrete but transmit some light parallel to the concrete surfaces. Prefabricated light transmitting concrete blocks and panels are available and can be used for load-bearing structures since the optical fibers do not negatively impact concrete strength. The optical fibers act like slits, carrying light across the concrete using the principle of total internal reflection.
Carbon nanotubes have unique properties compared to other carbon allotropes due to their covalent bonding arrangement. They are 1000x thinner than a human hair but 200x stronger than steel. Scientists are interested in carbon nanotubes because they are excellent conductors of electricity and heat and have potential applications in solar cells, sporting goods, electronics, displays and other technologies. Carbon nanotubes can be manufactured through molecular engineering techniques like chemical synthesis or self-assembly.
The document discusses carbon nanotube (CNT)/epoxy matrix nanocomposites. It notes that dispersing CNTs homogeneously in the epoxy matrix is important to exploit their potential but is difficult due to aggregation. Methods to improve dispersion include using surfactants or functionalizing CNTs. Functionalization can degrade CNT properties so alternative methods are sought. The properties of CNT/epoxy nanocomposites depend on the degree of CNT dispersion, with higher conductivity achieved above the percolation threshold.
This document summarizes Paulo Sergio Fonseca's research project on growing and characterizing monolayer molybdenum disulfide (MoS2) using chemical vapor deposition (CVD). The goals were to grow monolayer MoS2 islands using CVD, characterize the material properties using techniques like photoluminescence spectroscopy and atomic force microscopy, fabricate devices on the MoS2 using electron beam lithography, and investigate the electrical properties through transport measurements. Key accomplishments included the successful growth and characterization of CVD monolayer MoS2, as well as fabricating a device to enable future transport studies of the material's electron mobility.
This document provides an overview of carbon nanotubes, including their unique properties, production methods, and applications. Carbon nanotubes are extraordinarily strong and stiff, and can be metallic or semiconducting depending on their structure. There are several methods for producing carbon nanotubes, including arc discharge, laser ablation, and chemical vapor deposition. Carbon nanotubes show promise for applications in energy storage, healthcare, and environmental remediation due to their mechanical, electrical, and thermal properties.
This document summarizes a study on the electrical properties of electrodeposited zinc-copper-telluride (ZnCuTe) ternary nanowires embedded in polycarbonate membranes. Scanning electron microscopy confirmed the formation of uniform diameter nanowires equal to the pore diameters of 200nm, 100nm, and 50nm templates used. Electrical measurements found the nanowires exhibited linear and ohmic characteristics. Larger diameter nanowires showed higher electron transport than smaller ones. Temperature-dependent measurements from 308K-423K revealed electrical conductivity increased with temperature and decreased with smaller nanowire size, with ZnCuTe nanowires exhibiting negative temperature coefficients of resistance.
This document describes a new method for producing stable carbon nanotube (CNT) aerogels with high electrical conductivity and porosity. The method involves:
1) Forming a chemically cross-linked gel of CNTs in solution using a chemical cross-linker.
2) Drying the gel using supercritical CO2 to produce an aerogel without shrinkage.
3) Thermally annealing the aerogel in air, which improves electrical conductivity, mechanical stability, surface area, and porosity by reopening pores.
The resulting annealed CNT aerogels are highly porous (>99%), electrically conductive (1-2 S/cm), and have a large specific surface area (590
This document summarizes research on using electrodeposited manganese dioxide (MnO2) coatings on porous carbon substrates for capacitive deionization (CDI) applications. Two carbon substrates with different surface areas and morphologies were coated with MnO2 using galvanostatic and cyclic voltammetric deposition. Characterization of the coated electrodes found mixed MnO2 phases present. Testing in half-cell configurations showed that maximum ion uptake per mass was not necessarily optimal for practical CDI applications, where performance per electrode area is more important. The results suggest the structure and deposition method can impact how effectively the electrode volume participates in ion removal reactions.
Nano ceramics and composites have a variety of applications due to their unique properties at the nanoscale. Nanoceramics are ceramics composed of nanoparticles produced using methods like sol-gel processing. They can be used in applications like medical technology and energy storage due to properties like strength and flexibility. Nanocomposites contain one material with at least one dimension below 100nm. Polymer nanocomposites improve mechanical properties and transparency through high surface area reinforcement. Common preparation methods include sol-gel and electrospinning. Potential applications include lightweight materials, sensors, and abrasion resistance.
Enhancing Electrochemical Performance of V2O5 Thin Film by using Ultrasonic W...iosrjce
Ultrasonic weltering was used to enhance the electrochemical performance of V2O5 thin films deposited on stainless steel substrates for use as electrodes in supercapacitors. Structural, morphological, physical and electrochemical characterization showed that ultrasonic weltering resulted in more crystalline and porous films with increased specific surface area. This led to improved ion transport and a 19% increase in specific capacitance from 333 F/g to 397 F/g. Energy density also increased from 2.44 Wh/kg to 2.97 Wh/kg, while power density rose from 3.11 kW/kg to 3.52 kW/kg. Therefore, ultrasonic weltering produced structural and morphological changes that enhanced the supercapacitive properties
Synthesis and characterization of nanocompositessowmya sankaran
This document defines and discusses different types of nanocomposites. It begins by defining nanotechnology and some unique properties at the nanoscale. It then discusses different types of nanomaterials that can be used in nanocomposites like nanoparticles, nanotubes, and nanorods. The document outlines three main types of nanocomposites - metal matrix, ceramic matrix, and polymer matrix - and provides examples and processing methods for each type. It concludes by discussing several applications of nanocomposites in areas like food packaging, environmental protection, aerospace, automotive, and batteries.
This document discusses X-ray diffraction (XRD) spectroscopy and provides examples of applying XRD principles to characterize different materials. It describes the basic principles of how XRD works using Bragg's law and Miller indices to identify crystal planes. Examples are given for characterizing silver nanoparticles, graphite, graphene oxide, and zinc oxide nanoparticles using XRD, including estimating particle sizes from XRD peak widths and identifying functional groups from infrared spectroscopy. References are also provided for further reading.
This document discusses Molybdenum disulfide (MoS2) as a new material for biosensors. MoS2 is a 2D semiconductor with tunable band structure and high carrier mobility. It can be synthesized through mechanical exfoliation, solution methods, and chemical vapor deposition. MoS2 has applications in sensors, memory, photovoltaics due to its direct bandgap and flexibility. Functionalized MoS2 can be used to develop electrode-based and optical biosensors to detect molecules like glucose and dopamine. While MoS2 shows promise for flexible electronics and biosensing, further studies are needed to optimize device performance and compatibility with plastic substrates.
Electrochemical Supercapacitive Performance of Sprayed Co3O4 ElectrodesIJERA Editor
Nanocrystalline cobalt oxide (Co3O4) thin film electrodes were fabricated by spray pyrolysis method on conducting fluorine doped tin oxide (FTO) substrates using ammonia complexed with cobalt chloride (CoCl2. 6H2O) solution. The structural and morphological properties of Co3O4electrodes were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM).The surface morphology study showed the film formation of porous surface with clusters. The electrochemical supercapacitive properties ofCo3O4 electrodes were evaluated using cyclic voltammetry and galvanostatic charge-discharge method. The Co3O4electrodes showed maximum specific capacitance of 168 F/g in 1 M aqueous KOH electrolyte at the scan rate of 20 mV/s. The maximum specific energy and specific power of the cell are 2.2Wh/kg and 0.23 kW/kg, respectively.
Patent Landscape Report on “Dielectric Polymer Nanocomposites” by DexPatentCaroline Charumathy
The Dielectric Property of Polymer Nanocomposite is an emerging and fast moving concept in electrical insulation. It is used in wide range of applications including Energy storage devices, Thin films, Semiconductor devices and Electromagnetic shielding or as radar- absorbent materials (RAMs). This landscape report will help in understanding the developments relating to preparation and use of Dielectric Polymer Nanocomposites
To get in-depth analysis of specific technology areas and the competitive patent landscape similar to this, contact us.
Nanocomposites have various applications in aircraft construction and jet engines due to their beneficial properties. They can be used as strengthening elements in aircraft structures or as skin for honeycomb structures on wings and fuselages. Carbon-carbon composites with carbon fiber reinforcement and polymer or carbon matrices are used for high temperature components. Nanocomposites with zirconia matrices provide thermal protection for turboengine parts. Nanocoatings made from ceramics with nano-particles can increase adhesion, decrease oxygen permeability, and improve resistance to thermal shock for thermal barrier coatings on jet engines.
Fabrication and characterization of nickelijoejournal
This paper shows that nickel nanowires of length 11μm and diameters 800 and 15nm were grown within
the pores of nuclear track polycarbonate membrane by electrodepositing nickel. Surface morphology and
crystallographic structure of the deposited nanowires was investigated using SEM, TEM and XRD
respectively. It is found that low current density gives good result, while high current density leads to the
formation of curled nanowires. Fabricated nanowires were further investigated for electrical properties
and found that nanowires obey ohm’s law. Through structural characterization it has been observed that
the fabricated nanowires posses FCC lattice structure.
Carbon nanotubes with special application to the cnt reoinforced glass and glassRahul Dubey
The document discusses carbon nanotubes (CNTs), their properties, production methods, and applications. Specifically, it focuses on using CNTs to reinforce glass and glass-ceramic matrix composites. The key points are:
1) CNTs have excellent mechanical and thermal properties that make them promising reinforcements. Their production via electric arc discharge, laser ablation, or chemical vapor deposition controls their quality.
2) Manufacturing CNT-reinforced glass/glass-ceramic composites requires well-dispersed CNTs, strong interfaces, and consolidation to high densities using techniques like spark plasma sintering.
3) Preliminary results show the composites have improved hardness, elastic modulus
The document experimentally investigates aluminum alloy with multi-walled carbon nanotube (MWCNT) composite to increase mechanical properties using stir casting method. Aluminum 6061 alloy was used as the matrix and MWCNTs were added as reinforcement at 1 wt%. Samples were prepared via stir casting and characterized through optical microscopy, SEM, hardness testing, and tensile testing. Results showed that the MWCNT composite had higher hardness and tensile strength than the unreinforced aluminum alloy. Specifically, the 1 wt% MWCNT composite demonstrated improved proof stress, ultimate tensile strength, and hardness compared to the unreinforced alloy, indicating the MWCNTs successfully increased the mechanical properties of the aluminum matrix.
This document discusses nanostructures, their synthesis, and surface modification techniques. It defines nanostructures as having at least one dimension between 1-100 nm. Nanostructures are classified based on dimensionality as 0D, 1D, 2D, and 3D. Common synthesis methods include physical vapor deposition, chemical vapor deposition, and thermal spraying. Surface modification is done to change properties like reactivity, roughness, and corrosion protection. Common modification techniques are thermal spraying, PVD, and CVD.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
A study of Carbon Nanotubes as Smart Reinforcemants for Glass/ Glass ceramic ...Rahul Dubey
This document presents a study on carbon nanotubes (CNTs) as reinforcements for glass and glass ceramic matrix composites. CNTs have excellent mechanical and physical properties due to their nano-scale size. The document discusses methods of CNT production, their properties, and manufacturing of CNT-reinforced glass composites. Incorporating CNTs improves the mechanical, electrical and thermal properties of the brittle glass matrix. Potential applications include structural components, heat sinks, and thermal barrier coatings. However, more research is still needed to fully understand CNT reinforcement effects and address issues like mass production costs and health impacts.
Light Transmitting Concrete or Transparent ConcreteSahla Fathima
Light transmitting concrete is a novel building material made of cement, mortar, and optical fibers. Optical fibers are drilled through the cement and mortar to guide light and utilize sunlight as a light source to reduce power consumption for illumination. The optical fibers compose only 4% of the concrete but transmit some light parallel to the concrete surfaces. Prefabricated light transmitting concrete blocks and panels are available and can be used for load-bearing structures since the optical fibers do not negatively impact concrete strength. The optical fibers act like slits, carrying light across the concrete using the principle of total internal reflection.
Carbon nanotubes have unique properties compared to other carbon allotropes due to their covalent bonding arrangement. They are 1000x thinner than a human hair but 200x stronger than steel. Scientists are interested in carbon nanotubes because they are excellent conductors of electricity and heat and have potential applications in solar cells, sporting goods, electronics, displays and other technologies. Carbon nanotubes can be manufactured through molecular engineering techniques like chemical synthesis or self-assembly.
The document discusses carbon nanotube (CNT)/epoxy matrix nanocomposites. It notes that dispersing CNTs homogeneously in the epoxy matrix is important to exploit their potential but is difficult due to aggregation. Methods to improve dispersion include using surfactants or functionalizing CNTs. Functionalization can degrade CNT properties so alternative methods are sought. The properties of CNT/epoxy nanocomposites depend on the degree of CNT dispersion, with higher conductivity achieved above the percolation threshold.
This document summarizes Paulo Sergio Fonseca's research project on growing and characterizing monolayer molybdenum disulfide (MoS2) using chemical vapor deposition (CVD). The goals were to grow monolayer MoS2 islands using CVD, characterize the material properties using techniques like photoluminescence spectroscopy and atomic force microscopy, fabricate devices on the MoS2 using electron beam lithography, and investigate the electrical properties through transport measurements. Key accomplishments included the successful growth and characterization of CVD monolayer MoS2, as well as fabricating a device to enable future transport studies of the material's electron mobility.
This document provides an overview of carbon nanotubes, including their unique properties, production methods, and applications. Carbon nanotubes are extraordinarily strong and stiff, and can be metallic or semiconducting depending on their structure. There are several methods for producing carbon nanotubes, including arc discharge, laser ablation, and chemical vapor deposition. Carbon nanotubes show promise for applications in energy storage, healthcare, and environmental remediation due to their mechanical, electrical, and thermal properties.
This document summarizes a study on the electrical properties of electrodeposited zinc-copper-telluride (ZnCuTe) ternary nanowires embedded in polycarbonate membranes. Scanning electron microscopy confirmed the formation of uniform diameter nanowires equal to the pore diameters of 200nm, 100nm, and 50nm templates used. Electrical measurements found the nanowires exhibited linear and ohmic characteristics. Larger diameter nanowires showed higher electron transport than smaller ones. Temperature-dependent measurements from 308K-423K revealed electrical conductivity increased with temperature and decreased with smaller nanowire size, with ZnCuTe nanowires exhibiting negative temperature coefficients of resistance.
This document describes a new method for producing stable carbon nanotube (CNT) aerogels with high electrical conductivity and porosity. The method involves:
1) Forming a chemically cross-linked gel of CNTs in solution using a chemical cross-linker.
2) Drying the gel using supercritical CO2 to produce an aerogel without shrinkage.
3) Thermally annealing the aerogel in air, which improves electrical conductivity, mechanical stability, surface area, and porosity by reopening pores.
The resulting annealed CNT aerogels are highly porous (>99%), electrically conductive (1-2 S/cm), and have a large specific surface area (590
This document summarizes research on using electrodeposited manganese dioxide (MnO2) coatings on porous carbon substrates for capacitive deionization (CDI) applications. Two carbon substrates with different surface areas and morphologies were coated with MnO2 using galvanostatic and cyclic voltammetric deposition. Characterization of the coated electrodes found mixed MnO2 phases present. Testing in half-cell configurations showed that maximum ion uptake per mass was not necessarily optimal for practical CDI applications, where performance per electrode area is more important. The results suggest the structure and deposition method can impact how effectively the electrode volume participates in ion removal reactions.
This document summarizes a lecture on thin film deposition techniques given by Dr. Toru Hara. It begins with definitions of thin films and their applications in electronic devices, optical coatings, optoelectronic devices, and quantum devices. It then provides brief introductions to specific applications like transistors, oxygen sensors, and LEDs. The main deposition techniques are also summarized, including chemical methods like plating, CSD, CVD, and ALD, as well as physical methods like thermal evaporation, sputtering, PLD, and MBE. Examples of equipment schematics are provided for many of the techniques.
The document provides an overview of a lecture on thin film deposition techniques given by Dr. Toru Hara. It discusses four main applications of thin films: 1) electronic semiconductor devices using band engineering, 2) optical coatings using refractive index engineering, 3) optoelectronic devices using both band and refractive index engineering, and 4) quantum devices using quantum dynamics design. It also describes common thin film deposition methods including chemical solution deposition, chemical vapor deposition, plating, and physical vapor deposition techniques and gives examples of their use in applications such as transistors, optical coatings, LEDs, and superlattices.
Ultra-optical characterization of thin film solar cells materials using core...IJECEIAES
This paper investigates on new design of heterojunction quantum dot (HJQD) photovoltaics solar cells CdS/PbS that is based on quantum dot metallics PbS core/shell absorber layer and quantum dot window layer. It has been enhanced the performance of traditional HJQD thin film solar cells model based on quantum dot absorber layer and bulk window layer. The new design has been used sub-micro absorber layer thickness to achieve high efficiency with material reduction, low cost, and time. Metallicssemiconductor core/shell absorber layer has been succeeded for improving the optical characteristics such energy band gap and the absorption of absorber layer materials, also enhancing the performance of HJQD ITO/CdS/QDPbS/Au, sub micro thin film solar cells. Finally, it has been formulating the quantum dot (QD) metallic cores concentration effect on the absorption, energy band gap and electron-hole generation rate in absorber layers, external quantum efficiency, energy conversion efficiency, fill factor of the innovative design of HJQD cells.
Nano Tailoring of MnO2 Doped Multiwalled Carbon Nanotubes as Electrode Materi...IRJET Journal
This document describes research on synthesizing manganese dioxide (MnO2) decorated multiwalled carbon nanotubes (MCNT) for use as an electrode material in supercapacitors. MnO2/MCNT nanocomposites were prepared through a simple solvo thermal method. Characterization of the materials was done using XRD, FESEM, TEM, EDS, UV-visible spectroscopy, FTIR, and Raman spectroscopy. The analyses revealed a porous, hierarchical structure of MnO2 coated on the MCNT surface. Increasing the annealing temperature improved the crystallinity and reduced the band gap of the MnO2/MCNT nanocomposite. The synthesized nanocomposite showed potential for high performance
TRIBOLOGICAL CHARACTERISTICS,ELECTRICAL PROPERTIES Arjun K Gopi
This document discusses tribological and electrical properties and provides summaries of several documents on related topics. It begins by defining tribological properties like wear resistance and coefficient of friction and electrical properties like dielectric strength. It then summarizes a document about polycarbazole nanocomposites with metal oxides for transparent electrode applications, describing their preparation, transparent and conductive properties. Following this, it summarizes documents about nanocomposites containing inorganic nanoparticles and conducting polymers and their various synthesis techniques and applications. It also briefly summarizes documents about carbon nanotube composites and their electrical properties and enhanced thermoelectric performance of single-walled carbon nanotube and polyaniline hybrid nanocomposites.
This document summarizes a study investigating the effects of morphology and pore size distribution on the physicochemical properties of graphite nanosheets/nanoporous carbon black/cerium oxide nanoparticle electrodes for electrochemical capacitors. Electrodes with different compositions of these materials were fabricated and their surfaces and pores were characterized using SEM. Electrochemical testing showed that electrodes with a mixture of materials exhibited the highest capacitance due to having macro, micro, and nano pores that increased the accessible surface area. Introducing cerium oxide nanoparticles created micro pores, while carbon black particles created macro pores and rearranged the graphite nanosheets. This nanoporous structure resulted in an electrode with the highest capacitance of 16.2 F/
NIMA 57184 Pilot production & commercialization of LAPPD™ Published Copy 05-0...Aileen O'Mahony
This document discusses progress on developing and commercializing Large Area Picosecond Photodetectors (LAPPDs). Key points discussed include:
1) Manufacturing 203mm x 203mm borosilicate glass capillary arrays (GCAs) to be used as substrates for microchannel plates (MCPs).
2) Optimizing MCP performance through atomic layer deposition (ALD) coating techniques to apply resistive and emissive coatings, and establishing an ALD coating facility.
3) Designing, constructing, and commissioning a vacuum facility to integrate and seal LAPPD tiles in order to produce pilot runs for commercialization.
Taken together, these steps outline a "
International Journal of Engineering and Science Invention (IJESI)inventionjournals
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Isesco j sci technol 2012
1. 44
Abstract
W
e report the perfor-
mance characteris-
tics of a high discharge
rate zinc-air cell, assem-
bled in compact, monopo-
lar and bipolar configura-
tions. The use of inorganic
MCM-41 membrane enables
the construction of a thin,
compact cell design with
ease. MCM-41 consists of
a hexagonally-ordered na-
nopore structure and is
characterized by its large
surface area and pore
volume, very narrow pore size distribution, hydrophilic in
nature and very good thermal stability. The monopolar
Zinc/MCM-41/air cell demonstrates discharge charac-
teristics of comparable per-
formance to commercial
cells. The cell, 1 cm2
area x
ca. 460 µm thick, possesses
limiting current of 27 mA,
maximum power output of
31mW,andvlumetricenergy
density of 924 Wh l-1
, rated
at 20 mA. A bipolar design
markedly improves the cell
performance. The cell, 1 cm2
area x ca. 920 µm thick,
possesses limiting current
of 95 mA, maximum power
output of 107 mW, and
volumetric energy density
of 1189 Wh l-1
.
Keywords: Bipolar design; Inorganic separator; MCM-
41 membrane; Zinc-air cell.
A High Rate Zinc/MCM-
41/Air Cell
Hens Saputra1
and Raihan Othman2
*
1
Pusat Teknologi Industri Proses
Badan Pengkajian dan Penerapan Teknologi (BPPT)
Jl. M.H. Thamrin No. 8
Jakarta 10340, Indonesia
2
Faculty of Engineering
International Islamic University Malaysia
P.O. Box 10
50728 Kuala Lumpur, Malaysia
*Corresponding author
Phone: +60-3-61964561
Fax: +60-3-61964853
Email: raihan@iium.edu.my
V o l u m e 8 - N u m b e r 1 3 - M a y 2 0 1 2 ( 4 4 - 5 3 )
ISESCO JOURNAL of Science and Technology
1. Introduction
Since Smee (1840) first described a primary, acidic
zinc-air cell in the literature, the zinc-air electrochemical
systems have been extensively studied and developed
(Backhurst et al., 1996; Chakkaravarthy et al., 1981;
Dewi et al., 2003; Ghiurcan et al., 2003; Goldstein et al.,
1999; Jiricny et al., 2000; Muller et al., 1998; Othman
et al., 2002; Saputra et al., 2011; Savaskan et al., 1992;
Zhang and Zhang, 2004). Popularly dubbed as breathing
batteries, zinc-air cells or metal-air batteries in general
are unique in that they utilize oxygen from the ambient
air as one of the electroactive materials. Hence this pro-
vides them with practically unlimited and free oxygen
supply. Further, the use of atmospheric oxygen does not
require storage, which in principle reduces the weight
and simplifies the battery design. Consequently, the metal
active material can accommodate the whole compartment
producing a high energy density battery.
Recently, we introduced inorganic MCM-41 membrane
as a new separator material for electrochemical cells
and demonstrated its efficacy in alkaline zinc-air cell
(Saputra et al., 2011). MCM-41 material belongs to a
group of mesoporous materials known as M41S, first
discovered by researchers of the Mobil Research and
Development Corporation in 1992 (Beck et al., 1992;
Kresge et al., 1992). This class of material possesses
regular arrays of uniform channels with large surface
area and is tuneable between 1 nm to 10 nm or more,
depending on the choice of surfactant, auxiliary
chemicals and reaction conditions (Øye et al.., 2001).
The use of MCM-41 membrane separator is attractive
due to its 3-in-1 functional features i.e. serving as an
electronically insulating separator, ionically conducting
membrane and electrolyte storage, simultaneously. The
6.Saputra 26/04/12 14:29 Page 44
2. Hens Saputraa and Raihan Othman / ISESCO Journal of Science and Technology - Volume 8, Number 13 (May 2012) (44-53)
45
customary polymer based separators are hydrophobic in
nature, thus require an additional absorbent interseparator
material as the electrolyte reservoir, particularly for
compact cell design. Furthermore, the fabrication of
MCM-41 membrane is simply by dip-coating procedure.
As a result, the membrane separator could be designed
to be sufficiently thin and the construction of bipolar cell
configuration could be done with ease. In the present
work, we report the fabrication and performance charac-
teristics of bipolar Zn/MCM-41/air cell. The positive
attributes of MCM-41 membrane separator as mentioned
above resulted in a high rate capacity cell which is of
comparable performance with commercial zinc-air cell,
if not better.
2. Materials and Methods
2.1 Preparation of MCM-41 membrane
MCM-41 membrane was fabricated onto the zinc
anode substrate using the dip-coating technique. The
parent solution for synthesis consisted of quarternary
ammonium surfactant, cethyltrimethylammonium bromide
C16H33(CH3)3NBr (CTAB), hydrochloric acid, deionized
water, ethanol, and tetraethylortosilicate (TEOS) with
molar ratio formulation of 0.05 CTAB, 1.0 TEOS, 0.5
HCl, 25 C2H5OH and 75 H2O. After the parent solution
was stirred for an hour (about 200 rpm) at room tempe-
rature of 30°C, the zinc substrate was dipped into the
parent solution and then air dried. A one-time dipping
process normally resulted in MCM-41 film thickness of
ca. 1 µm (Jia et al., 2004; Sano et al., 1997). We applied
three times dipping procedure to ensure that the mem-
brane would be thick enough to avoid defects such as
cracking and pinhole.
2.2 Characterization of MCM-41 membrane
The structural formation of MCM-41 membrane
onto the zinc substrate was verified using X-ray dif-
fraction (Cu Kα radiation, a scan range of 1 - 8 degrees
of 2θ and a scan speed of 2° min-1
). Its surface morpho-
logy was observed using an Atomic Force Microscopy
(AFM).
2.3 Zinc-air cell components and fabrication
2.3.1 Zinc anode
Zinc anode was prepared from an electrodeposition
process in order to obtain a high purity active material
with high surface area. An acidic chloride plating bath
was utilized. The electrolytic cell consisted of zinc foil
(99.9 % purity) as the working electrode and copper foil
as the counter electrode-cum-substrate. The copper sub-
strate was clamped by a home-made acrylic board holder.
The cell holder served to fix the electrode spacing and
to define the deposition area. The electrode spacing was
fixed at 30 mm and the holder possessed a window of
1 cm x 1 cm square area for zinc deposition. The electrolyte
consisted of zinc chloride (2 M) as the metal source and
ammonium chloride (2 M) as the supporting electrolyte.
Deposition current density was fixed at 100 mA cm-2
for
a duration of 1.5 hours. The electrodeposition set up and
parameters were adopted from the work of Nor Hairin
(2011). The resulting zinc deposits weighed 0.35 g and
ca. 100 µm thick. Figure 1 compares the surface mor-
Figure 1. SEM micrographs indicating the high surface area obtained from electrodeposited zinc as compared to compact zinc foil.
6.Saputra 26/04/12 14:29 Page 45
3. Hens Saputraa and Raihan Othman / ISESCO Journal of Science and Technology - Volume 8, Number 13 (May 2012) (44-53)
46
phology images between a compact zinc foil and the
electrodeposited zinc. It clearly signifies the high surface
area advantage of the zinc electrodeposits. The images
were observed using Field-Emission Scanning Electron
Microscope (FE-SEM) (JED-2100, JEOL Co. Ltd.). Nor
Hairin (2011) reported that zinc electrodeposits prepared
from the set up described above possessed specific sur-
face area in excess of 300 m2
g-1
and porosity of 62 %.
2.3.2 Air cathode
Acommercially available air cathode sheet (ca. 350 µm
thick) was utilized. The air cathode consisted of lami-
nated structures of fibrous carbon supported by a nickel
mesh and the air-side of the electrode covered with a gas
permeable, hydrophobic, Teflon layer. The membrane
permits ambient air oxygen to diffuse into the system.
The Teflon hydrophobic characteristic maintains the
crucial triple interface (air/oxygen-liquid/ electrolyte-
solid/conductor) requirement for an effective functioning
of the air electrode (Chakkaravarthy et al., 1981).
2.3.3 Separator and electrolyte
MCM-41 membrane, prepared onto the zinc anode
substrate, served as the cell's separator as well as the
electrolyte storage due to its hydrophilic characteristic.
An aqueous KOH electrolyte (6 M) was utilized. The
main issue concerning the use of MCM-41 membrane
separator in caustic alkaline environment is its stability
since it is a silica-based structure. However, we disco-
vered that the material is tolerable up to 70 % of KOH
weight ratio content without adversely causing electro-
chemical cell failure or short circuiting (Saputra et al.,
2012). The ordered silica network only diminished when
the KOH content reached 80 wt. %. The KOH weight
ratio content was calculated from the following relation
where wKOH(aq) and wMCM-41 denote the weight of aqueous
KOH electrolyte and MCM-41 material respectively.
2.3.4 Cell design
The planar structure of monopolar cell design is
depicted in Figure 2. The cell dimension was ca. 1 cm2
area x ca. 460 µm thick. The bipolar cell design was
assembled from positives consisting of two single air
electrodes facing back to back, and a single negative
placed in between. The negative electrode comprised of
(1)
Figure 2. Schematic illustration of monopolar Zn/MCM-41/air cell.
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4. Hens Saputraa and Raihan Othman / ISESCO Journal of Science and Technology - Volume 8, Number 13 (May 2012) (44-53)
47
electroplated zinc on both sides of the copper substrate
and coated with MCM-41 membrane. The cell dimension
was 1 cm2
area x ca. 920 ºm thick. Figure 3 illustrates
the bipolar cell configuration.
2.4 Cell characterizations
The assembled cells were characterized according to
their open circuit potential (OCV), polarization curve,
power density profile and discharge capacity. An Eco
Chemie (The Netherland) Autolab Galvanostat/ Poten-
tiostat was utilized to perform the measurements. The
characterizations were conducted at ambient room
temperature.
A polarization profile is essentially a V-I plot i.e. the
variation of operating voltage as a function of discharge
current. Power density plot can be subsequently obtained
by measuring the cell power output, P (product of V and
I) at each particular discharge current. Based on the P-I
plot, the maximum power that the cell could deliver is
readily obtained.
Cell discharge capacity is a measure of total charge
quantity that an electrochemical cell could supply. In
this work, we adopted a galvanostatic discharge test.
3. Results and Discussion
MCM-41 mesoporous structure is constructed from
cationic surfactant, cetyltrimethyl-ammonium bromide
(CTAB), and the resulting organic template finally
covered by silica from tetraethylorthosilicate (TEOS).
The transition between different forms of aggregates is
determined by the critical micelle concentration (CMC).
Since there are more than one, transition occurs over the
concentration spectrum, the CMC at lowest concentration
is designated as CMC1 and the subsequent CMCs
designated as CMC2, CMC3 and so on. At very low
concentration, the surfactant molecules are randomly
dispersed in solution. As the concentration reaches
CMC1, spherical micelles are formed in which the outer
surface comprised of the hydrophilic heads of surfactant
molecules, while the tails of these molecules are directed
toward the centre of the sphere. Increase of concentration
to CMC2 causes a transition from the spherical micelles
to more elongated or rod-like micelles. Further increase
in concentration causes the orientation and close packing
of the elongated micelles into hexagonal arrays of
MCM-41 structure. This is the liquid crystalline state
termed as the middle phase or hexagonal phase (Lee and
Rathman, 2001).
The pore size of MCM-41 structure varies between
1-10 nm and is determined by the length of carbon chain
of CTAB cationic surfactant (Saputra, 2003; Kresge et al.,
1992; Øye et al., 2001). Repeated measurements from
our earlier work have ascertained that the as-synthesized
MCM-41 material possessed a narrow pore size distri-
bution which centred around 2 nm, BET (Brunauer-
Emmett-Teller) surface area of 1200 m2
g-1
, and pore
volume density of 1.08 cm3
g-1
(Saputra, 2003; Saputra
et al., 2011a ). The pore surface of MCM-41 is covered
by silanol groups (Si-OH) formed during the synthesis
of the material. The density of silanol groups is around
2.5-5 nm-2
and very much depends on the template removal
conditions (Chen et al., 1996). The silanol group, in parti-
cular the Q3
group ((SiO)3Si-OH), serves as hydration
site (Zhao et al., 1998). The hydrophilic characteristic
of MCM-41 material is attributed to the existence of this
type of silanol group which forms around 60-80 % of
the silanol group.
MCM-41 hexagonal lattice structure is characterized
by low angle X-ray diffraction peaks as listed in Table 1
(Kresge et al., 1992; Øye et al., 2001). The dominant
(100) diffraction (2θ≈2°) normally suppressed the
remaining peaks (Jia et al., 2004). Figure 4 depicts the
X-ray diffractogram of the as-synthesized MCM-41
material which confirms its structural formation. The
AFM topography image of Figure 5 reveals the high
surface area nature of the membrane.
Figure 3. Bipolar Zn/MCM-41/air cell configuration
6.Saputra 26/04/12 16:01 Page 47
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48
Figure 5. AFM surface topology image of the MCM-41 membrane.
Figure 4. X-Ray diffractogram of the as-synthesized MCM-41 confirming the existence of hexagonal lattice structure.
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49
TABLE 1. Characteristic of MCM-41 X-ray diffractogram.
hkl
100
110
200
210
d/Å
39.8
22.9
19.8
14.9
°
The fabricated Zn/MCM-41/air cells registered a
stable open circuit voltage (OCV) value of 1.5 V.
Figure 6 displays the profile of operating voltage as a
function of discharge current, for both cell configurations.
Bipolar cell configuration possesses better polarization
profile. The improvement in the operating voltage as a
result of bipolar design was approximately 10 % in ave-
rage, i.e. around 120 mV. The enhancement in the cell's
limiting current for bipolar design was even more
substantial. Limiting current is the highest load current
of which the cell is capable to deliver prior to the abrupt
drop in the operating voltage. Monopolar cell was capable
to deliver at most 27 mA, but for bipolar cell the limiting
current was extended almost to an order of magnitude of
95 mA. Figure 7 depicts the performance comparison in
term of power output. As the power output is obtained
from the product of operating voltage and load current,
the difference between the two profiles are more pro-
minent. Monopolar cell registered a maximum power
output of 31 mW at load current of 27 mA while the
bipolar cell delivered a maximum power output of 107
mW at load current at 95 mA, i.e. more than threefold
enhancement.
Discharge capacity of an electrochemical cell is an
empirical quantity which is a function of discharge cur-
rent. In order to obtain an optimum cell capacity, the
monopolar cell was subjected to various discharge cur-
rents. Table 2 below highlights the cell discharge charac-
teristics obtained at load current of 10 mA, 15 mA, 20
mA and 30 mA. Obviously, optimum cell performance
was obtained at load current of 20 mA i.e. based on the
cell capacity and total energy output.
Figure 6. Polarization profiles of monopolar and bipolar cell configurations.
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50
Figure 7. Power output profiles of monopolar and bipolar cell configurations.
TABLE 2. Discharge characteristics of monopolar Zn/MCM-41/air cell at
various load currents.
148
76
104
29
1.24
1.23
1.23
1.20
24.7
18.9
34.5
14.7
30.5
23.1
42.5
17.6
10
15
20
30
Discharge
Duration
(min)
Average
Operating
Voltage (V)
Discharge
Capacity
(mAh)
Total Energy
Output
(mWh)
Discharge
Current
(mA)
Cell discharge capacity (C) is a measure of zinc
active material utilization at a particular load current
and calculated from the product of discharge current (Id)
and discharge duration (t)
Total energy output (Q) is obtained from the product
of Id and the area under the discharge plot (operating
voltage vs. discharge duration)
where An is the area under the discharge plot, Vop(t) is the
instantaneous operating voltage of the cell, and ∆t = tf - to
is the discharge duration. An can be estimated using the
Riemann's Sum approximation
n is the number of data points, ∆x is the interval between
data points, and f(Ci) is the mid-point value between
data point i-1 and i (i = 1,2,3…) i.e. the average cell
potential value between successive data points.
(2)
(3)
(4)
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51
Figure 8 illustrates the discharge performance com-
parison between the monopolar and bipolar cell designs,
rated at 20 mA. The bipolar cell registered a discharge
capacity of 87.5 mAh and possessed total energy output
of 109.4 mWh, an improvement factor of 2.5 as com-
pared to the monopolar cell. We further evaluated the
bipolar cell discharge capability at higher load currents,
as displayed in Figure 9. Table 3 summrizes the discharge
characteristics obtained from the bipolar cell. Oxygen
reduction is the rate limiting reaction in metal-air system
(Chakkaravarthy et al., 1981). A bipolar cell design
doubles the active surface area of the air electrode. As
such, the cell high rate capability was improved
substantially.
Figure 9. Discharge performance
of bipolar cell rated at various
load currents
Figure 8. Discharge curves of
monopolar and bipolar cell confi-
gurations rated at constant cur-
rent of 20 mA
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52
TABLE 3. Discharge characteristics of bipolar Zn/MCM-41/air cell at various
load currents.
260
106
50
33
21
1.26
1.25
1.24
1.21
1.13
87.5
70.0
51.7
44.6
34.6
109.4
89.0
62.5
54.1
39.1
20
40
60
80
100
Discharge
Duration
(min)
Average
Operating
Voltage (V)
Discharge
Capacity
(mAh)
Total Energy
Output
(mWh)
Discharge
Current
(mA)
The discharge characteristics obtained from the
zinc/MCM-41/air monopolar cell are comparable to the
published product datasheet for Duracell's zinc-air
button cells as listed in Table 4. The limiting current and
maximum power output are comparable even for button
cell DA630 which is of larger size (15.57 mm diameter,
6.17 mm height). Although the rated capacity of the
button cell is much higher, its volumetric size of 1.17 cm3
is almost 25 times bigger that the present cell's volume
of ca. 0.05 cm3
(1 cm2 area size and 0.46 mm thick). In
short, the zinc-air cell employing MCM-41 membrane
as the separator material demonstrates equivalent
performance to the commercial cell, if not better. The
bipolar design further enhanced the cell discharge
characteristics by more than twofold.
TABLE 4. Characteristics of Duracell's zinc-air button cells
(Bender et al., 1995).
5.84 x 3.56
7.80 x 3.50
7.80 x 5.33
11.56 x 5.33
15.57 x 6.17
30.56 x 10.72
50
110
210
520
1000
6300
2
7
12
22
25
150
2.2
7.7
13.2
24.2
27.5
165
DA230
DA312
DA13
DA675
DA630
DA1204
Dimensions
Diameter
(mm) x
Height (mm)
Rated
Capacity
(mAh)
Limiting
Current, IL
(mA)
Maximum
output
IL x 1.1 V
(mW)
Cell Type
Conclusion
A feasible, compact and high discharge rate zinc/MCM-41/air cell has been demonstrated. Zinc/MCM-41/air cell
of monopolar design, measured 1 cm2
area x ca. 460 µm thick and weighed 50 mg, possessed the following properties:
open circuit voltage of 1.5 V, limiting current of 27 mA, maximum power output of 31 mW, and volumetric energy
density of 924 Wh l-1
, rated at 20 mA. A bipolar design further enhanced the cell performance; limiting current of
95 mA, maximum power output of 107 mW, and volumetric energy density of 1189 Wh l-1
. These characteristics are
in fact of comparable performance to commercial zinc-air cells. We attribute the high rate capacity of the cell to the
use of inorganic MCM-41 separator material. The ultrathin membrane structure, high surface area and porous nature,
and hydrophilic characteristics, are the key contributing factors.
Acknowledgement
The work was funded by research grant awarded by the ISESCO Centre for Promotion of Scientific Research
(ICPSR). The authors gratefully acknowledge the financial support.
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53
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