Week 1 Understanding Different Battery Chemistry
1ans)
| type | material | explanation | chemical reactions in lithium ion batteries |
| LCO | LiCoO2: anode material is LiaC6 and cathode material is LibCoO2 | it has high capacity and good life span but has low discharge current so it gets overheated and the internal resistance increases as it gets used up. |
Discharging: while discharging the negative electrode gives up electrons and gets oxidised. Charging: during charging, the negative electrode accepts electrons and gets reduced. so redox reactions occur. |
| LMO | LiMnO2: cathode is lithium maganese spinel | it has reasonably good specific power and specific energy but poor performance and life span. | same as above. |
| NCA | LiNiCoAlO2: anode material is LiaC6 , cathode material is LibNiO.8CoO.15AlO.O5O2and carrier Li+ | they have high specific energy,long life span and good specific power. but high cost and safety is compromised. | same as above |
| NMC | LiNiMnCoO2:cathode consists of one-third nickel, cobalt manganese but the ratio varies according to preference. | NMC batteries are used in electric vehicles and medical devices. it has high specific energy, good life span and overal stability is good. | same as above. |
| LFP | LiFePO4:the anode is graphite. | it has good specific power, excellent life span and it is safe to use . these batteries have good thermal stability. it has low specific energy. | same as above |
| LTO | Li2TiO3:the cathode material is LibFePO4 and the carries is Li+ions. Li-titinate is used as the negative electrode i.e anode |
they are used in UPS, aerospace and military uses ,wind and solar energy storage. they have low specic energy, but good life span, safety and performance.it has high cost. |
same as above. |
2ans)
| characterstic | LFP | NMC | LCO | LMO | LTO |
| specific energy | 90-120Wh/kg | 150-220Wh/kg | 150-200Wh/kg | 100=150Wh/kg | 50-80Wh/kg |
| energy density | 333Wh/l | 580Wh/l | 560Wh/l | 420Wh/l | 177Wh/l |
| charge rate | 1C | 0.7-1C[>1C shortens life] | 0.7-1C[>1C shortens life] | 0.7-1C[3C max] | 1C[5C max] |
| charge voltage | 3.5-3.65VPC | 4.2VPC | 4.2VPC | 4.2VPC | 2.85VPC |
| life cycle (depending on depth of discharge) | 2000-4000 | 1000-2000 | 500-1000 | 300-700 | 3000-7000 |
|
thermal runaway [in degree centigrade] |
270 | 210 | 150 | 250 | NA |
| prone to thermal runaway | no | yes | yes | yes | no |
| cost | $ | $ | $$ | $$ | $$$ |
| applications | motive power and stationary needing high current and endurance | E-bikes. medical devices, EVs | mobile phones , laptops , tablets , cameras | power tools, medical devices | UPS, electric power trains, solar street lighting |