▎ 摘　　要

NOVELTY - Preparation of composite material of biomaterial substrate involves pretreating absorbent cotton, washing with deionized water and ethanol alternately, drying to obtain absorbent cotton (A), mixing stannic chloride pentahydrate and deionized water to obtain solution (B), mixing solution (B) with 6 mL of 25% aqueous ammonia to obtain solution (C), adding absorbent cotton (A) to solution (C), mixing, ultrasonically processing to obtain absorbent cotton (D), freeze-drying to obtain absorbent cotton (E), carbonizing in tube furnace to obtain carbonized absorbent cotton, ultrasonically processing 5 mg/mL graphene oxide dispersion to obtain solution (G), immersing carbonized absorbent cotton into solution (G), washing with deionized water, drying, calcining in muffle furnace to form nitrogen/tin oxide doped graphene oxide absorbent cotton composite material. The button battery is assembled in a glove box filled with an inert atmosphere. USE - Preparation of composite material of biomaterial substrate for button battery (all claimed). ADVANTAGE - The preparation method is simple and easy, and uses inexpensive raw material and provides substrate used as conductive carbon network, which improves the transmission of electrons. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for button battery, which comprises negative case, the composite material as self-supporting biological substrate to make negative electrode sheet for battery, metal sodium as counter electrode, electrolyte, separator, gasket, spring sheet and positive case. The electrolyte comprises sodium hexafluorophosphate-ethylene carbonate and dimethyl carbonate in volume ratio of 1:1. The separator is Celgard 2400 (RTM: polypropylene) membrane.