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Classification and characteristics of lithium ion batteries

Lithium-ion batteries have the advantages of high energy density, light weight, no memory effect, and environmental protection, and are widely used in electric vehicles, energy storage equipment, etc., such as electric vehicles, electric forklifts, AGV cars, golf carts, drones, notebooks computer etc. Lithium-ion batteries are divided into ternary lithium batteries, lithium iron phosphate batteries, lithium manganese oxide batteries, lithium cobalt oxide batteries and polymer batteries.

1. LiFePo4 battery: refers to a lithium-ion battery that uses LiFePO4 as the positive electrode material. It includes positive electrode, negative electrode, electrolyte, separator, battery case, etc. BYD blade batteries use Lifepo4, because of the low energy density, lifepo4 batteries are mainly used in electric forklifts, electric golf carts, sightseeing cars, electric patrol cars, photovoltaic energy storage, etc.

Advantages: long life, it can achieve cycle life of more than 2000 times, support fast charge and fast release. Good safety performance. In terms of high temperature resistance, the electric heating peak of Lifepo4 battery can reach 350¡ãC-500¡ãC.Compared with ternary lithium batteries, lifepo4 batteries are low in cost.

Disadvantages: low energy density, lifepo4 battery is not resistant to low temperature.

2. Ternary lithium battery: The positive electrode material uses a ternary polymer containing three metal elements: nickel, cobalt, and manganese (or aluminum). Because of its long battery life, it is widely used in electric vehicles with high battery life requirements. The Ningde era produced more ternary lithium batteries, and developed and launched lower-cost sodium-ion batteries.

Advantages: high energy density. The nominal voltage of the cell can reach 3.7V, which is higher than the 3.2V of lithium iron phosphate, with high output power and longer battery life. The low temperature performance is better, and the battery life decay of ternary lithium battery in winter is better than that of lithium iron phosphate battery.

Disadvantages: poor safety, poor high temperature resistance, higher cost than Lifepo4 battery, about 1000 cycle discharges, slightly shorter life than lithium iron phosphate battery.

3. Lithium manganate battery: Lithium manganate battery refers to a battery that uses lithium manganate material (LiMn2O4) as the positive electrode. The nominal voltage of lithium manganate battery is 2.5~4.2v, and the nominal voltage is 3.7V. Nissan LEAF uses lithium manganese oxide.

Advantages: low cost, good cathode material at low temperature. Low resistance enables fast charging and high current discharging.

Disadvantages: poor high temperature resistance, easy to generate gas, expansion, etc., short cycle life, generally 600-800 times.

4. Lithium cobalt oxide battery is the first positive electrode material for commercial lithium-ion batteries. Lithium cobalt oxide has three phases, namely layered structure HT-Li-CoO2, spinel structure LT-LiCoO2 and rock salt phase Li -CoO2. Lithium cobalt oxide batteries have extremely high volume energy density and a nominal voltage of 3.7V. They are widely used in consumer electronic devices, such as MP3, mobile phones, and notebook computers. Because of their poor safety, they are not suitable for power batteries.

Advantages: superior electrochemical performance, high volume-to-energy ratio

Disadvantages: poor safety, short cycle life.