high energy and capacity cathode material for li ion battries
Post on 11-Sep-2014
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Recent development in cathode materials for li-ion batteries drag the industries view towards it due to their high discharge rate compare to older ones.TRANSCRIPT
VISVESVARAYA TECHNOLOGICAL UNIVERSITY
centre for post graduate studies, Bangalore
seminar
on
High Capacity and High Energy Density Cathode Materials for Lithium Ion Battery
ByNatrajUSN: 1VW12INT12
Under the Guidance ofDr. Dinesh RSpecial officer, VTU CPGSB
INDEX
Introduction to Battery – Timeline
Lithium ion battery
Cathode materials
Advantages and Disadvantages of LI-Ion
Batteries
Advances in cathode materials
Promising cathode materials
Methodologies
References
Battery
A battery is a transducer that converts chemical
energy into electrical energy and vice versa.
It contains
An anode - source
A cathode - sink
An electrolyte - the separation of ionic
transport and electronic transport
Types: Primary and secondary
Introduction to Li-Ion Battery
The name of “lithium ion battery” was given by T. Nagaura and K. Tozawa
The concept of “lithium ion battery” was firstly introduced by Asahi Kasei Co. Ltd
Lithium ion batteries were first proposed by M. S. Whittingham in the 1970’s. Whittingham used TiS2 as the cathode and Lithium metal as the anode.
The first commercial lithium-ion battery was released by Sony in 1991
Why Li-Ion Battery?
Li is lightest metal
one of the highest standard reduction potentials (-3.0 V)
Theoretical specific capacity of 3860 Ah/kg in comparison with 820 Ah/kg for Zn and 260 Ah/kg for Pb
performance is related not only capacity but also to how fast current can be drawn from it: specific energy (Wh/Kg), energy density (Wh/cm3) and power density (W/Kg)
Advantages of Lithium-ion batteries
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
Cathode materials
A cathode is the electrode of an electrochemical cell at which reduction occurs
Common cathode materials of Lithium-ion batteries are the transition metal oxide based compounds such as LiCoO2, LiMn2O4, LiNiO2, LiFePO4
characteristics of cathode materials
A high discharge voltage
A high energy capacity
A long cycle life
A high power density
Light weight
Low self-discharge
CATHODE MATERIALS
Material Structure
Potential vs. Li/Li+, average v
Specific capacity, mAh/g
Specific energy, Wh/kg
LiCoO2 Layered 3.9 140 546
LiNi0.8Co0.15Al0.05O2
(NCA)
Layered 3.8 180-200 680-760
LiNi1/3Co1/3Mn1/3O2
(NMC)
Layered 3.8 160-170 610-650
LiMn2O4 Spinel 4.1 100-120 410-492
LiFePO4 olivine 3.45 150-170 518-587
Ways to Improve Cathode Performance
• Increasing Energy Density
• Thin nano-plate materials
• 30 nm LiFePO4 nano-plates performed better than thick
material
• Surface Coating of cathodes with either ionically or
electronically conductive material
• AlF3 coating on oxide materials is shown to improve
performance
Problems in the usage of Cathode materials
Raw material cost
Environmental impact of large-scale cells and mass
production
Production cost of solid-state synthesis using high and long
heating process
Heat generation from the cathode in a fully charged state
Sensitivity of safety for charge cutoff voltages
Low practical capacity of the cathode being half that of a
carbonaceous anode
Methodologies
There are several methods to synthesize the cathode materials of average
particle size and good crystallinity.
Hydrothermal process
Solvothermal process
Supercritical fluid process
Spray pyrolysis process
Conclusions and what does the future hold
In present day common Lithium transition compounds such as
LiCoO2, LiNiO2, LiMn2O4 and LiFePO4 are used as cathode material
in battery cell production, and they have shown a good performance
during charge and discharge cycling
For the future there are still a number of actions of interest to further
develop the performance of derived LiFePO4/C cathode material
We expect upcoming researches on this new framework will lead to
better cathode materials for lithium-ion batteries
References•Directed growth of nanoarchitectured LiFePO4 electrode by solvothermal synthesis and their
cathode properties
Authors: Dinesh Rangappa, Koji Sone, Tetsuichi Kudo, Itaru Honma
•Synthesis of LiMn2O4 nanoparticles made by flame spray pyrolysis
Authors: T. J. Patey,ab R. Bu¨ chel,c M. Nakayamab and P. Nova´k*a
•Monodisperse Porous LiFePO4 Microspheres for a High Power Li-Ion Battery Cathode by
Solvothermal process
Authors: Chunwen Sun, Shreyas Rajasekhara, John B. Goodenough,* and Feng Zhou
•Flame spray-pyrolyzed vanadium oxide nanoparticles for lithium battery cathodes
Authors: See-How Ng, Timothy J. Patey et.al
•Rapid one-pot synthesis of LiMPO4 (M = Fe, Mn) colloidal nanocrystals by supercritical
ethanol process
Authors: Dinesh Rangappa,* Koji Sone, Masaki Ichihara, Tetsuichi Kudob and Itaru Honma*
•Recent developments in cathode materials for lithium ion batteries
Author: Jeffrey W. Fergus ……. and
many more