Week 1 Understanding Different Battery Chemistry

1.Prepare a table which includes materials & chemical reactions occurring at the anode and cathode of LCO, LMO, NCA, NMC, LFP and LTO type of lithium ion cells.Give your detailed explanation on it.

Working of Lithium ion battery:

1)When charging the battery:

               

The electrolyte filled in the battery carries positive charged lithium ions from anode to cathode.The movement of positively charged lithium ions generates free electrons in anode which produces a charge at the positive terminal. The electric current then flows from the current collector through a device being powered to the negative current collector. The separator blocks the flow of electrons inside the battery.

2)When discharging:

                     

While the battery is discharging and supplying an electric current, the anode generates lithium ions to the cathode, generating a flow of electrons from one side to the other. When plugging in the device, the opposite reaction happens, the cathode releases lithium ions and anode receives them.

Energy density and Power density:

Energy density is the amount of energy in a given mass (or volume) calculated in Wh/kg and power density is the amount of power in a given mass calculated in W/kg. The distinction between the two is similar to the difference between Energy and power. Batteries have a higher energy density than capacitors, but a capacitor has a higher power density than a battery. This difference comes from batteries being able to store more energy, but capacitors can give off energy more quickly.

Lithium ion cells are classified into different types based on the chemical compositions:

• LCO - Lithium Cobalt Oxide (LiCoO2)
• LMO - Lithium Manganese Oxide (LiMn2O4)
• NCA - Lithium Nickel Cobalt Aluminium Oxide (LiNiCoAlO2)
• NMC - Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2)
• LFP - Lithium Iron Phosphate (LiFePO4)
• LTO - Lithium Titanium Oxide (LiTiO2)

Type	Anode	Cathode	Anode reaction	Cathode reaction
LCO	graphite carbon	lithium cobalt oxide
LMO	graphite	Lithium manganese
NCA	graphite	Nickel Cobalt Aluminium
NMC	graphite	Nickel Manganese
LFP	graphite	Lithium Iron phosphate
LTO	lithium titanate	lithium manganese oxide

2.Compare the differences between each type of Li+ion batteries based on their characteristics.

	LCO	LMO	NCA	NMC	LFP	LTO
Voltage	3.60V nominal operating range 3-4.2V/cell	3.70V nominal operating range 3.0–4.2V/cell	3.60V nominal operating range 3.0–4.2V/cell	3.70V nominal  operating range 3.0–4.2V/cell	3.30V nominal operating range 2.5–3.65V/cell	2.40V nominal operating range 1.8–2.85V/cell
Specific energy	150–200Wh/kg	100–150Wh/kg	200-260Wh/kg	150–220Wh/kg	90–120Wh/kg	50–80Wh/kg
Charge (C-rate)	0.7–1C,charges to 4.20V	0.7–1C,charges to 4.20V	0.7C,charges to 4.20V	0.7–1C,charges to 4.20V	1C ,charges to 3.65V	1C, charges to 2.85V
Discharge (C-rate)	1C; 2.50V cut off	1C,2.50V cut-off	1C ,3V cut-off	1C,2.50V cut-off	1C,2.50V cut-off (lower that 2V causes damage)	10C, 1.80V cut-off
Cycle life	500–1000, related to depth of discharge, load, temperature	300–700	500	1000–2000	2000 and higher	3,000–7,000
Thermal runaway	150°C, Full charge promotes thermal runaway	250°C	150°C typical	210°C (410°F) typical	270°C	One of safest Li-ion batteries
Applications	Mobile phones, tablets, laptops, cameras	Power tools, medical devices, electric powertrains	Medical devices, industrial, electric powertrain (Tesla)	E-bikes, medical devices, EVs, industrial	Portable and stationary needing high load currents and endurance	UPS, electric powertrain (Mitsubishi i-MiEV, Honda Fit EV), solar-powered street lighting
About	Very high specific energy, limited specific power. Cobalt is expensive. Serves as Energy Cell. Market share has stabilized.	High power but less capacity; safer than Li-cobalt; commonly mixed with NMC to improve performance.	Shares similarities with Li-cobalt. Serves as Energy Cell. Mainly used by Panasonic and Tesla; growth potential.	Provides high capacity and high power. Serves as Hybrid Cell. Favorite chemistry for many uses; market share is increasing. Leading system; dominant cathode chemistry.	Very flat voltage discharge curve but low capacity. One of safest Li-ions. Used for special markets. Elevated self-discharge. Used primarily for energy storage, moderate growth.	Long life, fast charge, wide temperature range but low specific energy and expensive. Among safest Li-ion batteries. Ability to ultra-fast charge; high cost limits to special application.