Preparation method of solid electrolyte

A preparation method of a solid electrolyte, comprising the following steps:

• (1) adding a cellulose nanocrystal aqueous solution into a three-necked flask under the protection of nitrogen, then adding an initiator and a polymer monomer to the three-necked flask, magnetically stirring at a constant temperature of 20-80° C. until the reaction is complete, washing a product with water several times and drying the product to obtain a porous powder material;
• (2) moving the porous powder material obtained in step (1) into a sample bottle, dropping an amount of electrolyte solution into the sample bottle, sealing the sample bottle, storing the sample bottle in a 60-90° C. constant-pressure constant-temperature oven for 8-15 hours, then moving the sample bottle into a 60-90° C. vacuum constant-temperature oven, adjusting a content of the electrolyte solution to 10 wt %-15 wt %, and taking an amount of samples for hot-pressing to form a membrane, thereby obtaining a solid electrolyte membrane;
• (3) storing the solid electrolyte membrane obtained in step (2) in a glove box, and cutting the solid electrolyte membrane according to required specifications to obtain a target solid electrolyte;
• in the step (1), an addition ratio of the cellulose nanocrystal aqueous solution to the initiator to the polymer monomer is 40 ml:(0.05-0.1) g:(1-2) ml, and a solid content of the cellulose nanocrystal aqueous solution is 0.4%-1.2%;
• and
• in the step (2), a mass ratio of the porous powder material to an electrolyte added to the electrolyte solution is 1:(1-2).