Lithium-ion batteries are a new type of high-energy battery developed in the 20th century. The negative electrode of this battery is made of materials such as graphite, while the positive electrode uses lithium iron phosphate, lithium cobalt oxide, lithium titanate, etc. They entered practical application in the 1970s. Due to their advantages such as high energy density, high battery voltage, wide operating temperature range, and long storage life, they have been widely used in military and civilian small electrical appliances.
What are the advantages and disadvantages of lithium-ion power batteries, which are currently the rising star in the battery industry?
I. Advantages of Lithium-ion Batteries
1. It has high energy density, with a volumetric energy density and a mass energy density of 450 W·h/dm3 and 150 W·h/kg, respectively, and these values are constantly increasing.
2. The average output voltage is high (approximately 3.6V), which is 3 times that of Ni-Cd and Ni-l batteries.
3. High output power.
4. Low self-discharge, less than 10% per month, less than half that of Ni-Cd and Ni-Ml.
5. It does not have the same memory effect as Ni-Cd and Ni-MH batteries, and has superior cycle performance.
6. It can be charged and discharged quickly, and the capacity can reach more than 80% of the nominal capacity when charged at 1C.
7. High charging efficiency, basically 100% after the first cycle.
8. Wide operating temperature range: -30~+45℃. With improvements in electrolyte and cathode, it is expected to be extended to -40~+70℃, and the low temperature range may be extended to -60℃.
9. No maintenance required.
10. It is relatively environmentally friendly and is called a green battery.
11. Long service life, with over 900 charge-discharge cycles at 100% DOD; when using shallow charge-discharge (30% DOD), the cycle count exceeds 5000.
II. Disadvantages of Lithium-ion Batteries
1. High cost, mainly due to the high price of the cathode material LiCoO2. With the continuous development of cathode technology, LiMn2O4, LiFePO4, etc. can be used as cathodes, which is expected to greatly reduce the cost of lithium-ion batteries;
2. Special protection circuitry is required to prevent overcharging or over-discharging;
3. Poor compatibility with ordinary batteries, because lithium-ion batteries can only be used as a replacement when three ordinary batteries (3.6V) are used.
Lithium-ion batteries have partially replaced traditional batteries in mobile phones, portable computers, camcorders, and cameras. High-capacity lithium-ion batteries are already being tested in electric vehicles and will become one of the main power sources for electric vehicles in the 21st century. They have also been applied in artificial satellites, aerospace, and energy storage.
