Classifying Lithium Batteries by Cathode Material

The performance, voltage, capacity, cost, and safety of lithium batteries are almost entirely determined by the cathode. The mainstream industry divides them into seven major systems: LCO (Lithium Cobalt Oxide), NCM/NCA (Ternary), LFP (Lithium Iron Phosphate), LMO (Lithium Manganese Oxide), Lithium-rich Manganese-based, LTO (Lithium Titanate, a special anode case), and LMFP (Lithium Manganese Iron Phosphate). Each will be analyzed in detail below.

1. Lithium Cobalt Oxide LiCoO₂ (LCO)

Core Structure

Layered oxide, cathode mainly based on single cobalt element, nominal voltage 3.7V, full charge 4.2V.

Advantages

1. Extremely high compacted density and high discharge specific capacity (140~155mAh/g);
2. Good cycle rate performance and fast charging;
3. Excellent low-temperature performance and the highest volumetric energy density;
4. Stable discharge platform with smooth voltage curve.

Disadvantages

1. Metal cobalt is scarce, cost is extremely high;
2. Poor thermal stability, prone to decomposition at high temperatures, high thermal runaway risk;
3. Moderate cycle life, can easily catch fire if overcharged;
4. Limited use in large-format power batteries.

Application Scenarios

Cell phones, laptops, Bluetooth earphones, smart watches, small digital 3C devices; early small drone batteries. Not used in passenger car power batteries.

2. Ternary Materials NCM / NCA (Nickel Cobalt Manganese / Nickel Cobalt Aluminum)

Classification and Naming Rules

Named according to nickel, cobalt, and manganese ratios:

• NCM111: Ni:Co:Mn = 1:1:1; NCM523, NCM622, NCM811 (high-nickel ternary)
• NCA: Nickel Cobalt Aluminum (mainstream for Tesla, ~Ni90), nominal voltage 3.65~3.7V, full charge 4.2V.

Core Characteristics

Nickel: increases capacity; Cobalt: stabilizes layered structure and enhances cycle life; Manganese/Aluminum: reduces cost and improves thermal stability.

1. High-nickel ternary (NCM811/NCA)
2. Medium-low nickel ternary (523/622/111)

Suitable Scenarios

High-end long-range passenger cars, hybrid vehicles, premium energy storage, aerospace, high-end electric motorcycles;

NCA is exclusively for Tesla; NCM811 is mainstream in domestic high-end electric vehicles.

3. Lithium Iron Phosphate LiFePO₄ (LFP)

Structure

Olivine structure, no precious metals cobalt or nickel, nominal 3.2V, full charge 3.65V.

Advantages

1. Abundant raw materials (iron and phosphorus), lowest cost;
2. Outstanding thermal stability, resistant to nail penetration and high temperature, top-tier safety;
3. Ultra-long cycle life (3000~6000 cycles), tolerant of deep charge/discharge;
4. Slow degradation, supports high-power fast charging, deep discharge capable.

Disadvantages

1. Low voltage platform, single-cell energy density about 30% lower than ternary;
2. Poor low-temperature performance, notable capacity fade at -10°C;
3. Low compacted density, resulting in larger battery pack volume for the same capacity.

Applications

Economical passenger cars, buses, trucks, large-scale energy storage stations, home energy storage, low-speed EVs, forklifts, backup power;

Currently the mainstream solution for domestic energy storage and affordable EVs.

4. Lithium Manganese Iron Phosphate LiMnFePO₄ (LMFP) – Next-Generation LFP Improvement

Principle

Doping manganese into the LFP olivine structure combines LFP's low cost with manganese's high voltage advantage, nominal 3.4V.

Advantages

1. Higher voltage than LFP, raises cell energy density by 10%~20%, narrowing the gap with ternary;
2. Inherits LFP's high safety, long cycle life, low cost, and absence of precious metals;
3. Fast-charging performance superior to conventional LFP.

Disadvantages

Manganese ions tend to dissolve, cycle stability slightly worse than pure LFP; manufacturing process is immature, mass-production cost marginally higher than LFP.

Positioning and Applications

Mid-range new energy vehicles, large-scale energy storage, outdoor storage; an upgrade path to replace LFP, currently ramping up massive production.

5. Lithium Manganese Oxide LiMn₂O₄ (LMO)

Structure

Spinel structure, manganese-based cathode, nominal 3.7V, full charge 4.2V.

Advantages

1. Completely free of cobalt and nickel, raw materials very cheap;
2. Extremely strong rate capability, instantaneous high power discharge; decent low-temperature performance.

Disadvantages

Fatal flaw: manganese readily dissolves at high temperature, dissolved manganese damages the graphite anode, leading to very poor cycle life; severe high-temperature degradation.

Applications

Only low-end low-speed vehicles, power tools, small-capacity digital devices, auxiliary batteries for buses; rarely used alone as a power battery, often blended with ternary.

6. Lithium-Rich Manganese-Based Cathode LRM-NMC (Next-Gen High Energy Route)

Structure

Layered solid-solution cathode, high manganese, low nickel-cobalt, ultra-high theoretical capacity.

Advantages

Theoretical specific capacity over 300mAh/g, energy density far surpassing ternary, low cost.

Disadvantages

Technology not yet mature: voltage decay, gas swelling, poor conductivity, poor cycle performance, mass production extremely difficult.

Stage

Laboratory/pilot stage, not yet commercialized at scale, targeted for next-generation long-range batteries.

7. Other Niche Cathode Systems

1. Lithium Titanate (Li₄Ti₅O₁₂, LTO, special: often used as anode, can also pair with cathodes to form LTO batteries)

Used with LMO/NCM cathodes; LTO is zero-strain, ultra-long cycle life (>10,000 cycles), ultra-safe, extremely fast charging;

Disadvantages: very low voltage, very low energy density, high cost; only used in specialty energy storage, port heavy trucks, low-temperature specialized equipment.

2. Lithium-Sulfur Batteries (S cathode)

Theoretical energy density extremely high, but polysulfide shuttle effect unsolved, poor cycling; only military testing, no commercial mass production.

3. Lithium-Air Batteries

Frontier research in labs, extremely far from commercialization.

Comparison Table of Key Parameters for Each System

Table

Industry Selection Summary

1. Pursuing range and northern low-temperature driving: High-nickel ternary NCM811/NCA
2. Pursuing low price, safety, long life, energy storage, southern commuting vehicles: LFP Lithium Iron Phosphate
3. Balancing range and cost, new-gen replacement for LFP: LMFP Lithium Manganese Iron Phosphate
4. Small portable electronic products: LCO Lithium Cobalt Oxide
5. High-power low-end low-speed equipment: LMO Lithium Manganese Oxide