A kind of porous composite separator and preparation method thereof, composite structure cell and lithium ion battery

Abstract

The invention discloses a porous composite material separator and a preparation method thereof, a composite structure electric core and a lithium ion battery. The separator contains high temperature resistant resin base material, flame retardant and inorganic high temperature resistant particles, the high temperature resistant resin base material is polyimide resin, polyethylene terephthalate resin, polyamide resin, polystyrene resin , any one or more of polysilane resins; the amount of flame retardant is 1% to 15% of the mass of the high-temperature-resistant resin substrate; the inorganic high-temperature-resistant particles are Al 2 o 3 、TiO 2 , ZrO 2 , SiO 2 For at least one of them, the amount of the inorganic high-temperature-resistant particles is 5% to 15% of the mass of the high-temperature-resistant resin base material. The porous composite separator has a high temperature resistance above 200°C, and has the properties of flame retardancy, high temperature resistance, corrosion resistance and impact resistance; it is formed independently and does not need to be coated on the pole piece or diaphragm, and the forming process will not damage the pole piece or diaphragm. The influence of the diaphragm ensures the performance and performance of the pole piece and the diaphragm itself.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a porous composite material separator, and also relates to a preparation method of the porous composite material separator, a battery cell with a composite structure and a lithium ion battery using the separator. Background technique [0002] At present, lithium-ion batteries are accepted by people because of their environmental protection, higher rated voltage, higher energy storage and longer service life, gradually replacing nickel-cadmium batteries that have occupied the market for nearly a hundred years. However, lithium-ion batteries have disadvantages, such as poor safety, and may cause an explosion when heated, especially nickel-cobalt lithium manganese oxide batteries, which have poorer safety performance. [0003] A conventional lithium-ion battery consists of a positive electrode, a negative electrode, and a PE / PP separator. The PE / PP separato...

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Problems solved by technology

However, in the preparation process, the slurry needs to be prepared first, and then the slurry is coated on the diaphragm and then dried to form a coating. This process is easy to cause damage to the diaphragm itself, affecting the performance and usability of the diaphragm, and may cause safety problems such as short circuit. At the same time, its inorganic filler is a metal hydroxide that undergoes a dehydration reaction at a high temperature, and water will be released during battery use, which will have a negative impact on the performance of the non-aqueous electrolyte, which is not conducive to popularization and use.

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