Week 1 Understanding Different Battery Chemistry

1. Please find below the table with comparison of various lithium ion batteries material and chemical reaction.

	LCO	LMO	NCA	NMC	LFP	LTO
FULLFORM	Lithium Cobalt Oxide	Lithium Manganese Oxide	Lithium Nickel Cobalt Aluminium Oxide	Lithium Nickel Cobalt Manganese Oxide	Lithium Iron Phosphate	Lithium Titanium Oxide
ANODE	Graphite	Graphite	Graphite	Graphite	Graphite	Lithium
CATHODE	Lithium Cobalt Oxide	Lithium Manganese Oxide	Lithium Nickel Cobalt Aluminium Oxide	Lithium Nickel Cobalt Manganese Oxide	Lithium Iron Phosphate	Lithium nickel Manganese cobalt oxide
ELECTROLYTE	Ethylene Carbonate	Lithium Halide	Ethylene Carbonate	Lithium salt	Ethylene Carbonate	Lithium salt
SEPARATOR	Polyethylene (PE) and Polypropylene (PP)	Polyethylene (PE) and Polypropylene (PP)	Polyethylene (PE) and Polypropylene (PP)	Polyethylene (PE) and Polypropylene (PP)	Polyethylene (PE) and Polypropylene (PP)	Polyethylene (PE) and Polypropylene (PP)
CHEMICAL REACTION	REDUCTION: CoO2 + Li+ + e- → LiCoO2 OXIDATION: LiC6 → C6 + Li+ + e- FULL REACTION: LiC6 + CoO2 ⇄ C6 + LiCoO2	REDUCTION: MnO2 + Li+ + e- → LiMnO2 OXIDATION: LiC6 → C6 + Li+ + e- FULL REACTION: LiC6 + Mn2O4 ⇄ C6 + LiMn2O4	REDUCTION: NiCoAlO2 + Li+ + e- → LiNiCoAlO2 OXIDATION: LiC6 → C6 + Li+ + e- FULL REACTION: LiC6 + NiCoAlO2 ⇄ C6 + LiNiCoAlO2	REDUCTION: NiMnCoO2 + Li+ + e- → LiNiMnCoO2 OXIDATION: LiC6 → C6 + Li+ + e- FULL REACTION: LiC6 + NiMnCoO2 ⇄ C6 + LiNiMnCoO2	REDUCTION: FePO4 + Li+ + e- → LiFePO4 OXIDATION: LiC6 → C6 + Li+ + e- FULL REACTION: LiC6 + FePO4 ⇄ C6 + LiFePO4	REDUCTION: 4Mn2O4 + 4Li+ + 4e- → 4LiMn2O4 OXIDATION: Li4Ti5O12 → Ti5O12 + 4Li+ + 4e- FULL REACTION: 4Mn2O4 + Li4Ti5O12 ⇄ 4LiMn2O4 + Ti5O12

In Lithium ion battery cell, during discharge, the electron flows from anode electrode to cathode electrode through external load during discharge and the positive ions pass from anode to cathode through separator. The process of anode giving up electrons during discharge is called oxidation.

During charging, the electron flows from cathode electrode to anode electrode through external load and the positive ions pass from cathode to anode through separator. The process of gaining electrons on anode duirng charging is called reduction.

The whole cycle of charging and discharging resembles the Redox reaction.

2. Please find below the comparison of characteristics of various Li ion batteries.

	LCO	LMO	NCA	NMC	LFP	LTO
Fullform	Lithium Cobalt Oxide	Lithium Manganese Oxide	Lithium Nickel Cobalt Aluminium Oxide	Lithium Nickel Cobalt Manganese Oxide	Lithium Iron Phosphate	Lithium Titanium Oxide
Anode	Graphite	Graphite	Graphite	Graphite	Graphite	Lithium
Cathode	Lithium Cobalt Oxide	Lithium Manganese Oxide	Lithium Nickel Cobalt Aluminium Oxide	Lithium Nickel Cobalt Manganese Oxide	Lithium Iron Phosphate	Lithium nickel Manganese cobalt oxide
Energy Density (Wh/kg)	560	420	600	580	333	177
Safety	Medium	Less	Low	Less	High	High
Life (years)	500-1000	300-700	500-1000	1000+	2000+	3000-7000
Voltage (V)	3.6	3.9	3.6	3.6	3.2	2.3 - 2.4
Thermal Runway (deg C)	150	250	150	210	270	Highest
Charge current rate C	0.7-1 C	0.7-1 C	0.7 C	0.7-1 C	1 C	1 C
Discharge current rate C	1 C	1 C	1 C	1-2 C	1 C	10 C

Energy Density: the energy density is factor to figure the capacity of 1 kilogram of battery chemistry can hold.

Safety: LFP & LTO are the safest among the all other Li-ion batteries

Voltage: LTO has low nominal voltage of 2.3V and LMO has high nominal voltage of 3.9V

Thermal Runway: It is the temperature above which the battery starts derate/malfunction. By the above data, we can see that LFP & LTO has highest thermal runway.

Charge current rate: Higher charge rate reduces the charging time of the battery.

Discharge current rate: Higher discharge rate drains the battery at faster rate. From the data, LTO has higher discharge rate.