What Is a Li-ion Lithium Battery Diaphragm?

Ⅰ. What is the function of a li-ion lithium battery diaphragm?

In the structure of lion batteries, the diaphragm is one of the key internal components. The performance of the diaphragm determines the interface structure and internal resistance of the li-ion lithium battery, and directly affects the battery's capacity, cycle, and safety performance. A diaphragm with excellent performance plays an important role in improving the overall performance of the battery.

The main purpose of the diaphragm is to separate the positive and negative electrodes of a li-ion lithium battery to prevent the two poles from contacting and short-circuit. In addition, it also has the function of allowing electrolyte ions to pass through. The diaphragm material is non-conductive, and its physical and chemical properties have a great influence on the performance of the battery.

Ⅱ. The types of li-ion lithium battery diaphragms

Li-ion lithium battery diaphragms can be divided into different types based on structure and composition. There are three main types that are more common in the market, namely porous polymer diaphragm, non-woven diaphragm, and inorganic composite diaphragm.

1. Porous polymer diaphragm

It refers to a li-ion lithium battery diaphragm with an even pore distribution prepared by mechanical methods, thermally induced phase separation methods, immersion precipitation methods and other methods.

2. Non-woven diaphragm

It is composed of oriented or random fibers, and is usually combined with organic matter or ceramic gel to obtain li-ion lithium battery diaphragms with better chemical and physical properties.

3. Inorganic composite diaphragm

Most of them are li-ion lithium battery diaphragms obtained by compounding inorganic nanoparticles and high polymers.