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Nanowire battery1
This document discusses nanowire batteries as an improvement over traditional lithium-ion batteries. It provides background on primary and secondary batteries, common battery types such as zinc-carbon and alkaline, and advantages of lithium-ion batteries like high energy density. The document then discusses how nanotechnology can be used to improve lithium-ion batteries by using silicon nanowires for the anode instead of graphite. Silicon can store more lithium than graphite but tends to fracture during charging/discharging. Nanowires prevent fracturing even as the silicon expands and contracts. The document concludes by suggesting that if battery technology improved at the same rate as computer chips, car batteries would be the size of a penny.
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Nanowire battery1
- 1. Nanowire batteries=Lithium-Ion Battery + Nano-technology By:ADITYA KALYANAPU (10AN1A0402) Department of Electronics & Communication Engineering BALAJI INSTITUTE OF ENGINEERING AND SCIENCES Laknepally, Narsampet – 506331
- 2. Primary vs. SecondaryBatteries Primary batteries are disposable because their electrochemical reaction cannot be reversed. Secondary batteries are rechargeable, because their electrochemical reaction can be reversed by applying a certain voltage to the battery in the opposite direction of the discharge.
- 3. Standard Modern Batteries Zinc-Carbon:used in all inexpensive AA, C and Zinc-Carbon D dry-cell batteries. The electrodes are zinc and carbon, with an acidic paste between them that serves as the electrolyte. (disposable) Alkaline: used in common Duracell and Alkaline Energizer batteries, the electrodes are zinc and manganese-oxide, with an alkaline electrolyte. (disposable) Lead-Acid: used in cars, the electrodes are lead Lead-Acid and lead-oxide, with an acidic electrolyte. (rechargeable)
- 4. Battery types. Nickel-cadmium: (NiCd) Nickel-cadmium rechargeable, “memoryeffect” Nickel-metal hydride: (NiMH) hydride rechargeable no “memory effect” Lithium-Ion: (Li-Ion) Lithium-Ion rechargeable no “memory effect”
- 5. Recharge-ability & the“memory effect” Recharge-ability: basically, when the direction of electron discharge (negative to positive) is reversed, restoring power. the Memory Effect: (generally) When a Effect battery is repeatedly recharged before it has discharged more than half of its power, it will “forget” its original power capacity. Cadmium crystals are the culprit! (NiCd)
- 6. Lithium. Periodic Table Symbol:Li Atomic Weight: 3 (light!) Like sodium and potassium, an alkali metal. (Group 1 – #s 1 through 7) Highly reactive, with a high energy density. Used to treat manic-depression because it is particularly effective at calming a person in a “manic” state.
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- 8. Lithium (Ion) BatteryDevelopment In the 1970’s, Lithium metal was used but its instability rendered it unsafe and impractical. Lithium-cobalt oxide and graphite are now used as the lithium-Ionmoving electrodes. The Lithium-Ion battery has a slightly lower energy density than Lithium metal, but is much safer. Introduced by Sony in 1991.
- 9. Advantages of Using Li-IonBatteries POWER – High energy density means greater power in a smaller package. 160% greater than NiMH 220% greater than NiCd HIGHER VOLTAGE – a strong current allows it to power complex mechanical devices. LONG SHELF-LIFE – only 5% discharge loss per month. 10% for NiMH, 20% for NiCd
- 11. Disadvantages of Li-Ion EXPENSIVE-- 40% more than NiCd. DELICATE -- battery temp must be monitored from within (which raises the price), and sealed particularly well. REGULATIONS -- when shipping Li-Ion batteries in bulk (which also raises the price). Class 9 miscellaneous hazardous material UN Manual of Tests and Criteria (III, 38.3)
- 12. The Intersection “In termsof weight and size, batteries have become one of the limiting factors in the development of electronic devices.” http://“The problem with...lithium batteries is that none of the existing electrode materials alone can deliver all the required performance characteristics including high capacity, higher operating voltage, and long cycle life. Consequently, researchers are trying to optimize available electrode materials by designing new composite structures on the nanoscale.”
- 13. “Nano”-Science and -Technology The attemptto manufacture and control objects at the atomic and molecular level (i.e. 100 nanometers or smaller). 1 nanometer = 1 billionth of a meter (109 ) 1 nanometer : 1 meter :: 1 marble : Earth 1 sheet of paper = 100,000 nanometers
- 14. Nano S &T (cont’d) Nano-science: research of the Nano-science differing behavioral properties of elements on the nano scale. Conductivity (electric/thermal), strength, magnetism, reflectivity.... Sometimes these properties differ on the nanoscale. Carbon is particularly strong on the nano scale. C60 = “Fullerene,” a.k.a “buckyball”
- 15. Nano S &T (cont’d) Nano-technology: the use of nanoscale Nano-technology materials in critical dimensions of mechanical devices. Nanotubes -- carbon molecules have greater mechanical strength at less weight per volume. Nanotransistors -- the computer industry’s best technology features microchips with transistors as small as 45nm. Batteries with nanoscale materials deliver more power quickly with less heat.
- 16. Environmental Impacts andUse of Nanotechnology Smaller scale technology means less resources used and less waste. The EPA recently issued research grants to use nanotechnology to develop new methods of detecting toxins in water.
- 17. An example ofthe intersection... From graphite to metallic tin (electrodes), but metallic tin isn’t great either…yet. “...the biggest challenge for employing metallic tin...is that it suffers from huge volume variation during the lithium insertion/extraction cycle, which leads to pulverization of the electrode and very rapid capacity decay." But nanotechnology could offer a solution...
- 18. Another example... “The storagecapacity of a Li-Ion battery is limited by how much lithium can be held in the battery's anode, which is typically made of carbon. Silicon has a much higher capacity than carbon, but also has a drawback.” “Silicon placed in a battery swells as it absorbs positively charged lithium atoms during charging, then shrinks during use as the lithium ion is drawn out of the silicon. This cycle typically causes the silicon to pulverize, degrading the performance of the battery.”
- 19. The Nano-technology solution... “Thelithium is stored in a forest of tiny silicon nanowires, each with a diameter one one-thousandth the thickness of a sheet of paper. The nanowires inflate to four times their normal size as they soak up lithium but, unlike other silicon shapes, they do not fracture.” See next slide…
- 20. • Photos takenby a scanning electron microscope of silicon nanowires before (left) and after (right) absorbing lithium. Both photos were taken at the same magnification. The work is described in “High-performance lithium battery anodes using silicon nanowires,” published online Dec. 16 in Nature Nanotechnology.
- 21. ADVANTAGES • • • • • • To save sufficientamount of time. Eco friendly. Protects from explosions. Saves money. Light in weight. High storage capacity(4200mAh).
- 22. DISADVANTAGES • High temperatureis required(600900degree celsius.) • It is expensive. • Only anodes are manufactured by nanowires.
- 23. APPLICATIONS. • • • • Used in laptops. Usedin film making industries. Used in automobiles. Used in medical equipments.
- 24. Finally, an interestingidea... Background: battery research results in annual capacity gains of approximately 6% Moore’s Law: The number of transistors on a computer microchip will double every two years. (40 years of proof!) Idea: If battery technology had developed at the same rate, a heavy duty car battery would be the size of a penny.
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