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.

Answer:

Lithium Cobalt Oxide (LiCoO2):

• Its high specific energy makes Li-cobalt popular for mobile phones, laptops, and digital cameras.
• The battery consists of a cobalt oxide cathode and a graphite carbon anode.
• The cathode has a layered structure; lithium ions move from the anode to the cathode during discharge. The flow reverses on charge.
• The drawback of Li-cobalt is its relatively short life span, low thermal stability, and limited load capabilities (specific power).
• Li-cobalt should not be charged and discharged at a current higher than its C-rating.

Lithium Manganese Oxide (LiMn2O4):

• Li-manganese is used for power tools, medical instruments, as well as hybrid and electric vehicles.
• Li-ion cell with lithium manganese oxide as cathode material and a graphite carbon anode.
• The architecture forms a three-dimensional spinel structure that improves ion flow on the electrode, which results in lower internal resistance and improved current handling.
• A further advantage of spinel is high thermal stability and enhanced safety, but the cycle and calendar life is limited.
• Low internal cell resistance enables fast charging and high-current discharging.

Lithium Nickel Cobalt Aluminium Oxide (LiNiCoAlO2):

• Lithium nickel cobalt aluminium oxide battery, or NCA, has been around since 1999 for special applications.
• It offers high specific energy, reasonably good specific power, and a long life span.
• Less flattering are safety and cost.
• NCA is a further development of lithium nickel oxide; adding aluminium gives the chemistry more excellent stability.

Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2):

• One of the most successful Li-ion systems is a cathode combination of nickel-manganese-cobalt (NMC). Similar to Li-manganese, these systems can be tailored to serve as energy cells or power cells.
• Silicon added to graphite has the drawback that the anode grows and shrinks with charge and discharge, making the cell mechanically unstable.
• NMC is the battery of choice for power tools, e-bikes and other electric powertrains.
• The cathode combination is typically one-third nickel, one-third manganese and one-third cobalt, also known as 1-1-1.
• This offers a unique blend that also lowers the raw material cost due to reduced cobalt content. Another successful combination is NCM with 5 parts nickel, 3 parts cobalt and 2 parts manganese (5-3-2).
• Other combinations using various amounts of cathode materials are possible.

Lithium Iron Phosphate (LiFePO4):

• In 1996, the University of Texas (and other contributors) discovered phosphate as a cathode material for rechargeable lithium batteries.
• Li-phosphate offers good electrochemical performance with low resistance. This is made possible with nano-scale phosphate cathode material.
• The key benefits are high current rating and long cycle life, besides good thermal stability, enhanced safety and tolerance if abused.

Lithium Titanate (Li2TiO3):

• Batteries with lithium titanate anodes have been known since the 1980s.
• Li-titanate replaces the graphite in the anode of a typical lithium-ion battery and the material forms a spinel structure.
• The cathode can be lithium manganese oxide or NMC.
• Li-titanate has a nominal cell voltage of 2.40V, can be fast charged and delivers a high discharge current of 10C, or 10 times the rated capacity.
• The cycle count is said to be higher than that of a regular Li-ion. Li-titanate is safe, has excellent low-temperature discharge characteristics and obtains a capacity of 80% at –30°C (–22°F).

Names	Cathode	Anode	Seprator	Electrolyte	Cathode Reaction	Anode Reaction	Overall Reaction
Lithium Cobalt Oxide (LiCoO2)- LCO	Cobalt Oxide	Graphite	polyolifin	Ethelene Carbonate	LiCoO2 ↔ Li++ CoO2 + e-	LiC6 ↔ Li+ + C6 + e-	C6 +LiCoO2 ↔ LiC6 + CoO2
Lithium Manganese Oxide (LiMn2O4)- LMO	Manganese Oxide	Graphite	polyolifin	Lithium Halide	LiMnO2 ↔ Li+ + MnO2 + e-	LiC6 ↔ Li+ + C7 + e-	C6 + LiMn2O4 ↔ LiC6 + Mn2O4
Lithium Nickel cobalt Aluminum Oxide (LiNiCoAlO2)- NCA	Nickel Cobalt Aluminum Oxide	Graphite	polyolifin	Ethylene Carbonate	LiNiCoAlO2 ↔ Li+ + NiCoAlO2 + e-	LiC6 ↔ Li+ + C8 + e-	C6 + LiNiCoAlO2 ↔ LiC6 + NiCo AlO2
Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2)- NMC	Nickel Manganese Cobalt Oxide	Graphite	polyolifin	Lithium Salt	LiNiMnCoO2 ↔ Li+ +NiMnCoO2 + e-	LiC6 ↔ Li+ + C9 + e-	C6 + LiNiMnCoO2 ↔ LiC6 + NiMnCoO2
Lithium Iron Phosphate (LiFePO4)- LFP	Iron Phosphate	Graphite	polyolifin	Ethelene Carbonate	LiFePO4 ↔ Li+ + FePO4 + e-	LiC6 ↔ Li+ + C10 + e-	C6 + LiFePO4 ↔ LiC6 + FePO4
Lithium Titanate (Li2TiO3)- LTO	Manganese Oxide	Lithium Titanate	polyolifin	Lithium Salt	4LiMn2O4 ↔ 4Mn2O4 + 4Li+ + e-	Li4Ti5O4 ↔ Ti5O4 + 4Li+ + 4e-	4Mn2O4 + Li4Ti5O12 ↔ 4LiMn2O4 + Ti5O12

An excel sheet has been attached for reference "battery-reaction-details".

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

Answer:

LCO:

• Very high specific energy
• limited specific power.
• Cobalt is expensive.
• Serves as Energy Cell.
• Market share has stabilized.
• Early version; no longer relevant.

LMO:

• High power but less capacity
• safer than Li-cobalt
• commonly mixed with NMC to improve performance.
• Less relevant now
• limited growth potential.

NMC:

• Provides high capacity and high power.
• Serves as Hybrid Cell.
• Favorite chemistry for many uses
• market share is increasing.
• Leading system; dominant cathode chemistry

LFP:

• Very flat voltage discharge curve but low capacity.
• One of the safest Li-ions.
• Used for special markets.
• Elevated self-discharge.
• Used primarily for energy storage.
• moderate growth

NCA:

• Shares similarities with Li-cobalt.
• Serves as Energy Cell.
• Mainly used by Panasonic and Tesla.
• growth potential.

LTO:

• 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 a special application.

Name	Specific Energy (Wh/Kg)	Charge (C-Rate)	Discharge (C-Rate)	Cycle Life	Thermal Runway (℃)	Application
LCO	150-200	07.-1.0	1; 2.50V Cutt off	500-1000	150	Mobile Phones, tablets, Laptops, Cameras
LMO	100-150	0.7-1.0; 3C max.	1; 10C Possible with some cell. 30C pulse(5s); 2.50V Cutt off	300-700	250	Power tools, Medical devices, Electric powertrain
NMC	150-220	0.7-1.0C	1C, 2C Possible for some cell	1000-2000	210	E-bikes, Medical Dvices, EVs, Industrial
LFP	90-120	1C, 3hr charge	1C, 25C on some cell, 40A pulse(2s)	>2000	270	Portable and stationary needing high load current & endurance
NCA	200-260	0.7, 3hr charge typical; Fast charging possible	1C typical, 3.00V cutt off	500	150	Medical Devices, Industrial, Electric Powertrain(Tesla)
LTO	50-80	1C , typical 5C max.	10C, Possible 30C(5s) pulse	3000-7000	Safest Battery	UPS, Electric power train( Mitsubishi, Honda Fit EV), Solar power street lightning

An excel sheet has been attached for reference "battery-compare".