What is Lithium Battery

What is Lithium Battery

Blog Article

Working Principle

• Charging: During charging, lithium ions are extracted from the positive electrode (usually a lithium - containing compound such as lithium cobalt oxide) and move through the electrolyte to the negative electrode (typically graphite). At the same time, electrons flow through the external circuit to the negative electrode to maintain charge balance.


• Discharging: When discharging, the lithium ions move back from the negative electrode to the positive electrode through the electrolyte. The electrons flow through the external circuit from the negative electrode to the positive electrode, generating an electric current to power the connected device.

Structure

• Positive Electrode: Usually made of lithium - containing transition metal oxides or phosphates, which can store and release lithium ions during charging and discharging. Common materials include lithium cobalt oxide (LiCoO2​), lithium manganese oxide (LiMn2​O4​), lithium iron phosphate (LiFePO4​), etc.


• Negative Electrode: Generally, graphite - based materials are used because of their good conductivity and ability to accommodate lithium ions. Some new materials such as silicon - based materials are also being researched and developed to improve the performance of the negative electrode.


• Electrolyte: It is a medium for lithium - ion conduction, usually composed of organic solvents and lithium - salt compounds. The most commonly used lithium salt is lithium hexafluorophosphate (LiPF6​). The electrolyte plays a crucial role in determining the battery's performance and safety.


• Separator: It is a thin - film - like material placed between the positive and negative electrodes to prevent direct contact between the two electrodes, thus avoiding short circuits. At the same time, it allows lithium ions to pass through freely. Polyolefin - based membranes are commonly used as separators.

Characteristics

• High Energy Density: It can store more energy in a relatively small volume and weight compared to traditional battery technologies such as nickel - cadmium and nickel - metal - hydride batteries, which makes it possible to power portable electronic devices for a long time.


• Low Self - Discharge Rate: The self - discharge rate of lithium - ion batteries is relatively low, usually about 5% - 10% per month. This means that when the battery is not in use, it can retain its charge for a long time, which is very convenient for users.


• No Memory Effect: Different from some traditional batteries, lithium - ion batteries do not have a memory effect. Users do not need to completely discharge the battery before charging, and they can charge it at any time without affecting the battery's performance and life.


• Fast Charging and Discharging Capability: Lithium - ion batteries can usually be charged and discharged at a relatively fast rate, which shortens the charging time of electronic devices and improves their usability. However, high - rate charging and discharging may have an impact on the battery's life, so appropriate charging and discharging strategies need to be adopted according to the specific situation.

Applications

• Portable Electronic Devices: Such as mobile phones, laptops, tablets, digital cameras, etc. Lithium - ion batteries provide the necessary power for these devices, enabling them to be lightweight, compact, and have a long battery life.


• Electric Vehicles: As an important power source for electric vehicles, lithium - ion batteries provide the driving force for vehicles, helping to reduce dependence on traditional fossil fuels and achieve environmental protection and energy conservation.


• Energy Storage Systems: It is used in large - scale energy storage systems, such as the energy storage of solar and wind power generation. Lithium - ion batteries can store the surplus electricity generated during the day and release it at night or when the power supply is insufficient, playing a role in regulating the power grid and improving the stability and reliability of power supply.