I. Characteristics of Lithium-ion Battery Separators
The main performance requirements for lithium-ion battery separators include four major performance indicators: thickness uniformity, mechanical properties (including tensile strength and puncture resistance), air permeability, and physicochemical properties (including wettability, chemical stability, thermal stability, and safety).
II. Requirements for Lithium-ion Battery Separators
1. It has electronic insulation properties, ensuring mechanical isolation between the positive and negative electrodes.
2. It has a certain pore size and porosity to ensure low resistance and high ionic conductivity, and has good permeability to lithium ions.
3. Since the solvent of the electrolyte is a highly polar organic compound, the diaphragm must be resistant to electrolyte corrosion and have sufficient chemical and electrochemical stability.
4. It has good wettability to electrolytes and sufficient liquid absorption and moisturizing ability.
5. It should have sufficient mechanical properties, including puncture strength and tensile strength, but the thickness should be as small as possible.
6. It has good spatial stability and flatness.
7. Excellent thermal stability and automatic shutdown protection performance. Power batteries have higher requirements for separators, and composite membranes are usually used.
The main function of the lithium battery separator is to separate the positive and negative electrodes, preventing short circuits caused by contact between them. It also allows electrolyte ions to pass through. The separator material is non-conductive, and its physicochemical properties have a significant impact on battery performance.
