Modified high-heat-resistance polyamide coating diaphragm as well as preparation method and application thereof

The invention discloses a modified high-heat-resistance polyamide coating diaphragm as well as a preparation method and application thereof. According to the invention, a polyamide material is modified and dopamine is introduced as a lithium ion battery diaphragm composite coating, which is equivalent to introduction of quinonyl and catechol groups on a high-heat-resistance polyamide coating, so that the wettability of the diaphragm can be improved, and the pores of the diaphragm are controlled by adding a small molecule pore-forming agent. The prepared modified high-heat-resistance polyamide diaphragm has good heat resistance, the heat shrinkage rate at 200 DEG C for 1 h is smaller than 5%, the electrolyte contact angle of the modified high-heat-resistance polyamide diaphragm is kept at 0-5 degrees, and the modified high-heat-resistance polyamide diaphragm has good wettability. Therefore, the modified high-heat-resistance polyamide coating diaphragm has great development potential as a high-safety lithium io