Lithium-ion battery composition

Composition and recycling of lithium-ion battery

The lithium-ion battery is composed of the eletrolyte,separator, cathode and anode and the case.

The electrolyte in a lithium-ion battery can be a gel or a polymer, or a mixture of gel and polymer.

The electrolyte in Li-ion batteries acts as a medium for the transport of ions in the battery. It usually consists of lithium salts and organic solvents. The electrolyte plays a key role in ion transport between the positive and negative electrodes of a lithium-ion battery, ensuring that the battery can achieve high voltage and high energy density. The electrolyte is generally composed of high-purity organic solvents, lithium electrolyte salts and necessary additives carefully combined in specific proportions under specific conditions.

The cathode material types of the lithium-ion battery:

• LiCoO2
• Li2MnO3
• LiFePO4
• NCM
• NCA

 The cathode materials consists of the over 30% costs of the whole battery.

The anode of the lithium-ion battery contains

 Then the anode of the lithium-ion battery consists of about 5-10 percentage costs of the whole battery. Carbon-based anode materials are a commonly used anode material for lithium-ion batteries. Compared with the traditional metal lithium anode, it has higher safety and stability. Carbon-based anode materials mainly come from natural and artificial graphite, carbon fiber and other materials. Among them, graphite is the main material, which has high specific surface area and electrical conductivity, and carbon materials also have good chemical stability and recyclability. However, the capacity of carbon-based negative electrode materials is relatively low, which cannot meet the requirements of some applications for higher capacity. Therefore, there are currently some researches on new carbon materials and composite materials, hoping to further improve the capacity and cycle life of carbon-based negative electrode materials.

It still has the silicon-carbon negtive electrode material. Silicon (Si) material: Compared with traditional carbon negative electrodes, silicon negative electrodes have higher specific capacity and energy density. However, due to the large expansion rate of the silicon material, it is easy to cause the volume expansion of the electrode, thereby shortening the life of the battery.

The separator of a lithium-ion battery is an important part of ensuring battery performance and safety. The main function of the separator is to separate the positive and negative electrodes, and at the same time, it can also form a channel for ion movement and maintain the necessary electrolyte. The performance and related parameters of the lithium-ion battery separator are introduced as follows:

1. Chemical stability: The diaphragm should have excellent chemical stability, good corrosion resistance and aging resistance under organic solvent conditions, and can maintain stable performance under harsh conditions such as high temperature and high humidity.

2. Mechanical strength: The separator should have sufficient mechanical strength and elasticity to ensure sufficient tensile strength and wear resistance to prevent damage during assembly or use.

3. Ionic conductivity: Under the organic electrolyte system, the ionic conductivity is lower than that of the aqueous electrolyte system, so the separator should have the characteristics of low resistance and high ionic conductivity. At the same time, in order to reduce the resistance, the thickness of the separator should be as thin as possible to make the electrode area as large as possible.

4. Thermal stability: When abnormalities or failures such as overcharge, overdischarge, and short circuit occur during battery operation, the separator must have good thermal stability. At a certain temperature, the diaphragm should soften or melt, thereby blocking the internal circuit of the battery and preventing battery safety accidents.

5. Sufficient wetting and controllable pore structure: The pore structure and surface coating of the separator should have sufficient wetting controllability to ensure the separator, thereby improving the power and cycle life of the battery. Generally speaking, polyethylene flake (PP) and polyethylene flake (PE) microporous diaphragms are common diaphragm materials at present, and the price is relatively cheap. But there are other lithium-ion battery separator materials, such as polyester, which have good performance, but the price is relatively high.