- #1
hurreechunder
- 18
- 3
Hi all - I have a question on the redox reactions in Li ion batteries. I'm not being able to figure out where the Li-> Li+ + e- half cell reaction is actualy happening.
Take the standard LCO reaction:
LiCoO2 + C6 -> LiC6 + CoO2 (in reality, only 50% of the Li reacts this way, but let's ignore that)
The thing is that the Li is present in the LCO cathode as Li+ and it is again intercalated in the graphite anode as Li+
So the only redox happening in the reaction is the oxidation of Co from 3+ to 4+ and the reduction of C6 from 0 to -1.
In the discharge cycle, the C6 is losing one electron and expelling the Li+ while the LCO cathode is accepting an electron as well as a Li+ ion to reduce Co from 4+ to 3+.
I can't figure out where in the half cell reactions we are ever getting Li -> Li+ + e- as the Li remains as Li+ all through. However, without this half cell reaction, an Li ion battery cannot get the 3.7 V that it does.
Any help would be appreciated.
Take the standard LCO reaction:
LiCoO2 + C6 -> LiC6 + CoO2 (in reality, only 50% of the Li reacts this way, but let's ignore that)
The thing is that the Li is present in the LCO cathode as Li+ and it is again intercalated in the graphite anode as Li+
So the only redox happening in the reaction is the oxidation of Co from 3+ to 4+ and the reduction of C6 from 0 to -1.
In the discharge cycle, the C6 is losing one electron and expelling the Li+ while the LCO cathode is accepting an electron as well as a Li+ ion to reduce Co from 4+ to 3+.
I can't figure out where in the half cell reactions we are ever getting Li -> Li+ + e- as the Li remains as Li+ all through. However, without this half cell reaction, an Li ion battery cannot get the 3.7 V that it does.
Any help would be appreciated.