Lithium-ion battery is a kind of battery made of non-aqueous electrolyte solution with lithium metal or lithium alloy as negative electrode material. In 1912, Gilbert n. Lewis first proposed and studied lithium metal batteries. In the 1970s, M.S. Whittingham proposed and began to study lithium-ion batteries. Due to the very active chemical properties of metal lithium, the processing, storage and use of metal lithium have very high environmental requirements. Therefore, lithium-ion batteries have not been used for a long time. With the development of science and technology, lithium-ion batteries have become mainstream.
Lithium-ion batteries can be divided into two categories: lithium metal batteries and lithium-ion batteries. Lithium-ion batteries do not contain metallic lithium and can be recharged. The fifth-generation rechargeable lithium metal battery was born in 1996, and its safety, specific capacity, self-discharge rate and performance ratio are better than lithium-ion batteries. Due to its own high technical requirements, only a few companies in a few countries are currently producing such lithium metal batteries.
Lithium-ion batteries have the following advantages:
High energy density: According to different electrode materials, its mass can reach 150~200Wh/kg (540~720kJ/kg). The volume can reach 250~530Wh/L (0.9~1.9kJ/cm3). [2]
High open circuit voltage: with the change of electrode material, up to 3.3~4.2v.
High output power: up to 300~1500W/kg (@20 seconds), depending on electrode material. [1] (does not match source)
No memory effect: The lithium iron phosphate battery has no memory effect, the battery can be charged and discharged at any time without empty charging, and it is easy to use and maintain.
Low self-discharge: <5%~10%/month. The monitoring circuitry built into the smart Li-ion battery is even more efficient than the self-discharge current.
Wide operating temperature range: -20℃~60℃ work normally.
Fast charge and discharge
Therefore, lithium-ion batteries are widely used in consumer electronics, special products, special products and other fields. A lithium-ion battery is a rechargeable battery that works by moving lithium ions between positive and negative electrodes. Lithium-ion batteries use intercalated lithium compounds as electrode materials. At present, lithium cobalt oxide (LiCoO2), lithium manganese acid (LiMn2O4), lithium nickel acid (LiNiO2), and lithium iron phosphate (LiFePO4) are commonly used negative electrode materials for lithium ion batteries. At the same time, lithium-ion batteries also have the following disadvantages: (1) Overdischarge is not tolerated: in the case of overdischarge (the voltage during discharge is less than 3.0v), the excessively intercalated lithium ions will be fixed in the lattice and cannot be released again, resulting in shortened life. , and deep discharges are more likely to damage the battery. Therefore, using extremely low power can damage the battery, but as long as the battery is charged at high voltage multiple times, it is possible to reactivate the battery's maximum charge capacity. (2) Unbearable overcharge: During the overcharge process, the electrode is stripped by a large amount of lithium ions, and the lithium ions are not replenished in time, resulting in a long-term collapse of the lattice, which irreversibly reduces the storage of electrical energy. Therefore, Li-Ion batteries must be used frequently to prevent them from remaining fully charged and constantly plugged into the charger connector. It is necessary to keep the flow of electrons stored inside properly and maintain the long-term health of the battery. (3) Aging can't stand heat, unlike other rechargeable batteries, lithium-ion batteries will inevitably decline in natural slow cycle with cycle use, even without use, storage capacity will decrease, which is related to use (unless it is a vicious over-inflation Cycling results in the loss of lattice layers, as the aging process is more appropriately called loss), and is temperature dependent. A possible mechanism is the gradual addition of internal resistance, so high operating current electronics are more prone to thermal degradation, and should also be protected against external temperatures.