Understanding Different Battery Chemistry

Aim & Objectives

To prepare a table which includes materials and chemical reactions occurring at anode and cathode of LCO, LMO, NCA, NMC, LFP and LTO type of lithium ion cells.

Explanation

Figure below shows a schematic of a lithium-ion cell, but the basic idea applies generally.

Lithium ion cells have several advantages over other chemistries. They operate at higher voltages than other rechargeable cells, typically about 3.7V for lithium-ion versus 1.2V for NiMH or NiCd. Because of this, they tend to have higher energy density also. The higher voltage means that a single cell can often be used in a particular application rather than multiple NiMH or NiCd cells in series. While NiCd and NiMH do not require battery management circuitry for safe operation, all battery packs can potentially benefit from battery management: the battery management circuitry for lithium ion can be simplified by this reduced cell count. Lithium ion cells also have a lower self-discharge rate than other types of rechargeable cells. NiMH and NiCd cells can lose anywhere from 1–5% of their charge per day, even if they are not installed in a device. Lithium-ion cells, on the other hand, will retain most of their charge even after months of storage. The table below shows the materials and chemical reactions occurring at anode and cathode of lithium ion cells.

Battery Name	Anode Material	Cathode Material	Electrolyte	Separator	Reaction at Anode	Reaction at Cathode	Overall Reaction
LCO (Lithium Cobalt Oxide)	Graphite Carbon	Cobalt Oxide	Ethylene Carbonate	Polyolefin	LiC6 → xLi+ + xe− + C6	Li1−xCoO2 + xLi+ + xe− → LiCoO2	C6 + LiCoO2 ⟷ LixC6 + Li1−xCoO2
LMO (Lithium Manganese Oxide)	Graphite	Lithium Manganese spinal	Lithium Halide	Polyolefin	LiC6 → xLi+ + xe− + C6	Li1-xMn2O4 + xLi+ + xe- → LiMn2O4	C6 + LiMn2O4 ⟷ LixC6 + Li1−xMn2O4
NCA (Lithium Nickel Cobalt Aluminium Oxide)	Graphite	Lithium Nickel Cobalt Aluminium spinal	Ethylene Carbonate	Polyolefin	LiC6 → xLi+ + xe− + C6	Li1−xNiCoAlO2 + xLi+ + xe− → LiNiCoAlO2	C6 + LiNiCoAlO2 ⟷ LixC6 + Li1−xNiCoAlO2
NMC (Lithium Nickel Manganese Cobalt Oxide)	Graphite	Nickel Manganese Cobalt	Lithium Salt	Polyolefin	LiC6 → xLi+ + xe− + C6	Li1−xNiMnCoO2 + xLi+ + xe− → LiNiMnCoO2	C6 + LiNiMnCoO2 ⟷ LixC6 + Li1−xNiMnCoO2
LFP (Lithium Iron Phosphate)	Graphite	Phosphate	Ethylene Carbonate	Polyolefin	LiC6 → xLi+ + xe− + C6	LiFe(III)PO4 + xLi+ + xe− → LiFe(II)PO4 FePO4 + Li+ + e− → LiFePO4	C6 + LiFePo4 ⟷ LixC6 + Li1−xFePo4
LTO (Lithium Titanate)	lithium titanate	lithium manganese oxide or NMC	Lithium Salt	Polyolefin	LiTiO2 → xLi+ + xe− + TiO2	Li1-xMn2O4 + xLi+ + xe- → LiMn2O4	TiO2 + LiMn2O4 ⟷ LixTiO2 + Li1−xMn2O4

Conclusion

A table which includes materials and chemical reactions occurring at anode and cathode of LCO, LMO, NCA, NMC, LFP and LTO type of lithium ion cells were created.

Reference

[1] https://batteryuniversity.com/learn/article/types_of_lithium_ion

[2] https://www.science.org.au/curious/technology-future/lithium-ion-batteries