Automobile power batteries are the core components of electric vehicles. Batteries of different technical routes vary significantly in performance, cost and applicable scenarios. The following is an analysis of the main classifications and their advantages and disadvantages.
1. Lithium-ion batteries (mainstream technology)
Lithium-ion power batteries, referred to as lithium batteries, are batteries that use lithium metal or lithium alloy as negative electrode materials and non-aqueous electrolyte solutions.
1. Ternary lithium batteries (NCM/NCA)
Cathode materials: oxides of nickel (Ni), cobalt (Co), manganese (Mn) or aluminum (Al).
Advantages:
High energy density (200-300 Wh/kg) and long driving range;
Good low-temperature performance (can still maintain high capacity at -20℃);
Strong fast charging capability.
Disadvantages:
High cost (depends on scarce metals such as cobalt and nickel);
Poor thermal stability (easy to thermal runaway, requiring complex BMS protection);
Short cycle life (about 1000-2000 times).
Application: high-end passenger cars (such as Tesla and NIO).
2. Lithium iron phosphate battery (LFP)
Cathode material: lithium iron phosphate.
Advantages:
High safety (good high temperature stability, not easy to explode);
Long cycle life (3000-5000 times);
Low cost (no dependence on cobalt and nickel resources).
Disadvantages:
Low energy density (150-200 Wh/kg);
Poor low temperature performance (-10℃ capacity drops significantly);
Low voltage platform, more cells need to be connected in series.
Application: low-end electric vehicles, commercial vehicles (such as BYD blade batteries).
3. Other lithium-ion batteries
Lithium cobalt oxide (LCO): high energy density, but high cost and poor safety, mostly used in consumer electronics.
Lithium manganese oxide (LMO): low cost, good safety, but short life, used in hybrid models.
2. Nickel-metal hydride battery (transition technology)
Nickel-metal hydride battery is a secondary battery that can be charged and discharged repeatedly. It is a new type of green battery developed in the 1990s to replace traditional nickel-cadmium batteries.
Advantages:
High safety (overcharge/discharge resistance);
Good low temperature performance (available at -30℃);
Environmental protection (no heavy metal pollution).
Disadvantages:
Low energy density (60-120 Wh/kg);
High self-discharge rate (about 30% per month);
High cost (containing rare metals).
Applications: hybrid vehicles (such as Toyota Prius), rail transit, backup batteries, smart homes.
3. Lead-acid battery (gradually eliminated)
Classification: ordinary lead-acid battery, AGM (enhanced).
Advantages:
Extremely low cost (mature technology);
Good high-rate discharge performance (suitable for starting power supply).
Disadvantages:
Extremely low energy density (30-50 Wh/kg);
Short cycle life (300-500 times);
Severe pollution (contains lead and sulfuric acid).
Application: low-speed electric vehicles, fuel vehicle starting batteries.
4. Solid-state batteries (future technology)
Solid-state batteries can be understood as batteries using solid electrolytes. Solid-state batteries are non-flammable, do not produce liquid electrolytes, and are non-corrosive. Therefore, they are an effective way to solve battery safety problems.
Technical features: Replace liquid electrolytes with solid electrolytes.
Advantages:
High theoretical energy density (400+ Wh/kg);
Greatly improved safety (no leakage, non-flammable);
Long cycle life (up to 10,000 times).
Disadvantages:
Extremely high cost (complex manufacturing process);
Interface impedance issues to be resolved;
Not yet commercialized on a large scale.
Progress: Toyota, CATL and other companies are expected to mass produce by 2030.
5. Sodium-ion battery (emerging technology)
Advantages:
Rich raw materials (wide sodium resources);
Excellent low-temperature performance (80% capacity at -40℃);
Low cost (30% lower than lithium iron phosphate).
Disadvantages:
Low energy density (100-160 Wh/kg);
Cycle life needs to be improved (currently about 2,000 times).
Applications: energy storage, low-speed electric vehicles (CATL has released products).
6. Fuel cell (hydrogen energy)
Fuel cell is a power generation device that directly converts high-purity hydrogen and oxygen into electrical energy through chemical reactions.
Principle: Generate electricity through hydrogen-oxygen reaction, and the product is water.
Advantages:
Extremely high energy density (hydrogen storage is 10 times that of lithium batteries);
Fast hydrogenation (3-5 minutes);
Zero emissions.
Disadvantages:
High cost (platinum catalyst, hydrogen storage technology);
Lack of infrastructure (few hydrogenation stations);
Hydrogen production relies on fossil energy.
Application: Commercial vehicles, heavy trucks (such as Toyota Mirai).
Summary comparison table
| Battery type | Energy density | Safety | Cost | Lifespan | Applicable scenarios |
| ternary lithium battery | High | Medium | High | Medium | High-end electric vehicles |
| lithium iron phosphate battery | Medium | High | Low | Long | Mid-range vehicles, energy storage |
| nickel metal hydride battery | Low | High | Medium-high | Medium | Hybrid vehicles |
| lead-acid battery | Very low | High | Very low | Short | Low-speed vehicles, starting power sources |
| isomorphic battery | Very high (theoretical) | Very high | Very high | Extremely long | Future full scenarios |
| sodium ion battery | Low-Medium | High | Low | Medium | Energy storage, low-cost needs |
| hydrogen fuel cell | Very high | Medium | Very high | Medium | Commercial vehicles, long-distance transportation |
Trends and Challenges
Short term: Lithium iron phosphate (cost reduction) and ternary lithium (long battery life) coexist;
Medium term: Sodium ion batteries supplement the low-end market, and solid-state batteries are gradually commercialized;
Long term: Hydrogen fuel cells may become the main force of heavy trucks/aviation, but they rely on the maturity of the green hydrogen industry chain.