The improvement of the quality of new-type lithium-ion batteries is not only at the technical level, but also the improvement of raw materials or the substitution of inventions is also an important level. So what are the current new-type lithium-ion battery separators?
Ceramic coated diaphragm: Most diaphragm manufacturers have coating production lines.
Three-layer composite diaphragm: Celgard, the United States, Wuhan Huiqiang dry method single-pulling three-layer co-extrusion, Kunming Niumi dry method double-pulling three-layer co-extrusion.
Polyimide diaphragm: DuPont, Shenzhen Huicheng
Polyamide PA diaphragm: Mitsubishi of Japan
Yin ET non-woven diaphragm: Degussa, Germany
1. New lithium battery diaphragm: ceramic coated diaphragm
In order to solve the problem of poor high-temperature resistance of traditional lithium-ion battery separators, people have come up with a method to coat the surface of the separator with a single-layer or double-layer high-purity alumina ceramic material to improve the high-temperature resistance.
Coating thickness: generally single-layer coating 2-4um, such as: 2+16um, 4+12 ceramic diaphragm, or double-layer coating each 2um, such as: 2+12+2um.
PVDF coating: coating PVDF to improve the wettability of the separator and enhance the adhesion with the positive and negative electrodes
2. New lithium battery diaphragm: three-layer composite diaphragm
稰P diaphragm has a higher closed cell temperature and fusing temperature. 稰E diaphragm has a lower closed cell and fusing temperature temperature.
Considering safety performance, lithium ion battery separators usually require a lower closed cell temperature and a higher melting temperature. Therefore, it is necessary to combine PE and PP separators to produce a PP/PE/PP three-layer composite separator. . Among them, the PE diaphragm plays the role of fusing the fuse, providing better safety protection for the battery.
Production process: three-layer co-extrusion, three-layer composite
3. New lithium battery diaphragm: polyimide diaphragm
Features:
(1) Good high temperature resistance, significantly improving battery safety;
(2) Good liquid absorption and liquid retention, effectively improving battery cycle performance; high porosity, low internal resistance of the battery, and high energy conversion rate;
Production Process:
(1) Electrospinning method
(2) Phase separation method
Diaphragm industry development opportunities
Ceramic coated diaphragms, three-layer composite diaphragms, and polyimide diaphragms all improve the performance of the diaphragm from high temperature resistance, but polyimide diaphragms have better high temperature resistance, and ceramic coating and three-layer composites are difficult in terms of thickness. To be very thin, so the polyimide diaphragm has certain advantages.
Development opportunities: to ensure high temperature resistance, diaphragm consistency, high-rate discharge performance, and fill the gaps in the domestic high-end market.
