2. IntroductionIntroduction
• Demand for hybrid electric vehicles and the desire for
portable electronics, seeking high-performance anode
batteries.
• New material to build the next-generation rechargeable
lithium-ion batteries (LIBs) with high electrochemical
performance.
• The family of manganese oxide including the Na-Mn-O
system is regarded as one of the most promising electrode
materials for LIBs.
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3. 3
Lithium in the batteries
• Lithium is the lightest of metals and it can float on water.
• Highly reactive.
• These properties gives Lithium the potential to achieve
very high energy and power densities in high-density battery
applications such as automotive and standby power.
• A lithium cell can produce voltage from 1.5 V to about 3 V
based on the type of materials used.
4. 4
Lithium-ion battery (Li-ion Battery)
Li-ion batteries are secondary batteries.
• The battery consists of a anode of Lithium dissolved as
ions, into a carbon.
• The cathode material is made up from Lithium liberating
compounds, typically the three electro-active oxide materials,
• Lithium Cobalt-oxide (LiCoO2 )
• Lithium Manganese-oxide (LiMn2O4 )
• Lithium Nickel-oxide (LiNiO2)
5. 5
Principle
• During the charge and discharge processes, lithium ions are
inserted or extracted from interstitial space between atomic
layers within the battery.
• Simply, the Li-ion is transfers between anode and cathode
through electrolyte.
• Since neither the anode nor the cathode materials essentially
change, the operation is safer than that of a Lithium
metal battery.
8. 8
Advantages
• They have high energy density than other rechargeable
batteries
• They have less weight
• They produce high voltage out about 3.7V as compared
with other batteries.
• They have improved safety, i.e. more resistance to
overcharge
• Fast charge and discharge rate
Disadvantage
• They are expensive
• They are not available in standard cell types.
9. 9
Applications
• The Li-ion batteries are used in cameras, calculators.
• They are used in cardiac pacemakers and other
implantable device.
• They are used in telecommunication equipment,
instruments, portable radios and TVs, pagers.
• They are used to operate laptop computers and
mobile phones and aerospace application
10. New StrategyNew Strategy
A new strategy is carried out to prepare a highly
porous and electrochemically active Na0.55Mn2O4·1.5H2O
(SMOH) compound to be used as the anode.
The Na-Mn-O nanocrystal material dispersed within a
carbon matrix manifests a high reversible capacity of
1015.5 mA h g 1−
at a current density of 0.1 A g 1−
.
A polymorph of manganese oxide with cations such as
Na+
, K+
, and Li+
, has aroused intense research interest
because of its unique architecture with multiple
oxidation states that enrich redox reactions.
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11. Na0.55Mn2O4•1.5H2O (SMOH) nanocrystal homogeneously
dispersed within an amorphous carbon matrix, via
hydrothermal processes followed by calcination and etching
treatments.
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12. • The as-formed compound is comprised of nanocrystals
with typical crystallite size of about 5–10 nm, which are
well-dispersed within the amorphous carbon matrix.
• Carbon not only triggers the successful formation of the
new material, but also stabilizes the SMOH nanocrystals
against self-agglomeration and provides a conductive
channel to speed up the charge transfer efficiency of the
electrode.
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13. ConclusionConclusion
• High performance batteries are in demands, and
also with better cyclability.
• To our knowledge, there are no reports
focusing on the application of Na-Mn-O-based
compounds as anode materials for LIBs.
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For LIB the working potential for anode is ~0.5 to 2.5 and for cathode till ~3-4.7. So for anode Cu (0.337V wrt H) is selected as the oxidation potential of Cu ~2.7 wrt Li (3.045 V), so stable for anode.
Similarly for cathode, Al (1.662V wrt H) is selected as oxidation potential wrt Li is ~4.7. So stable for cathode.
a considerable capability of 546.8 mA h g−1 remains even after 2000 discharge/charge cycles at the higher current density of 4 A g−1, indicating a splendid cyclability.