LITHIUM- ION CELL
Li-ion cell is a rechargeable battery in which Li-ionoves between anode and cathode during charging and discharging.It is more popular than other batteries because of the various characteristics of lithium.Li has higher negative value for reduction potential and a lower atomic mass than any other metal.Only 6.94 g of Li is needed to provide one mole of electrons.
In typical litium ion cell ,the positive electrode is made by using a crystalline mixed oxide Li2O.Co2O3 or LiCoO2.The crystal contains both Li+ ion and Co3+ ion occupying the voids of the oxide array.Such crystals are usually synthesised by hydrolysis of the respective salt under hydrothermal condition.The negative terminal is made of graphite .The electrolyte is a solution of Li salt ,in an organic solvent such as ether or a solid phase polymer electrolyte which can transport Li+ ion.
Charging:-
During charging the cell act as an electrolytic cell,the electrical energy is converted into chemical energy.
At Anode (+) :
Some Li + ions get removed from the crystal lattice .and in the respective lattice site Co3+ ion get oxidized to Co4+ and electrical neutrality is maintained in the lattice.
At Cathode (-) :
The Li ion produced at the Anode get migrated through the electrolyte and get reduced to lithium atom at the graphite electrode.Li atoms are inserted between the layers of carbon atoms.This so called lithiated graphite , containing no Li metal as such.
Discharging
During discharging ,the cell acts as electro chemical cell,the chemical energy is converted to electrical energy.When the cell act as electrochemical cell ,LiCoO2 act as Cathode ,while the graphite act as anode.
Lithium ion cell is based on LiCoO2 has an EMF of 3.7 V.The cell is having high energy to weight ratio.They are used in cell phones,laptop computers,digital camera etc.The cell is not suitable for making large size of battery because of possibility of explosion.
Another type of Li-ion cell has been developed based on active materials like LiFePO4. The cell is having a potential of 3.3 v.The cell is suitable for making large size batteries suitable for automobile application.
Li-ion cell is a rechargeable battery in which Li-ionoves between anode and cathode during charging and discharging.It is more popular than other batteries because of the various characteristics of lithium.Li has higher negative value for reduction potential and a lower atomic mass than any other metal.Only 6.94 g of Li is needed to provide one mole of electrons.
In typical litium ion cell ,the positive electrode is made by using a crystalline mixed oxide Li2O.Co2O3 or LiCoO2.The crystal contains both Li+ ion and Co3+ ion occupying the voids of the oxide array.Such crystals are usually synthesised by hydrolysis of the respective salt under hydrothermal condition.The negative terminal is made of graphite .The electrolyte is a solution of Li salt ,in an organic solvent such as ether or a solid phase polymer electrolyte which can transport Li+ ion.
Charging:-
During charging the cell act as an electrolytic cell,the electrical energy is converted into chemical energy.
At Anode (+) :
Some Li + ions get removed from the crystal lattice .and in the respective lattice site Co3+ ion get oxidized to Co4+ and electrical neutrality is maintained in the lattice.
At Cathode (-) :
The Li ion produced at the Anode get migrated through the electrolyte and get reduced to lithium atom at the graphite electrode.Li atoms are inserted between the layers of carbon atoms.This so called lithiated graphite , containing no Li metal as such.
Discharging
During discharging ,the cell acts as electro chemical cell,the chemical energy is converted to electrical energy.When the cell act as electrochemical cell ,LiCoO2 act as Cathode ,while the graphite act as anode.
Lithium ion cell is based on LiCoO2 has an EMF of 3.7 V.The cell is having high energy to weight ratio.They are used in cell phones,laptop computers,digital camera etc.The cell is not suitable for making large size of battery because of possibility of explosion.
Another type of Li-ion cell has been developed based on active materials like LiFePO4. The cell is having a potential of 3.3 v.The cell is suitable for making large size batteries suitable for automobile application.
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