▎ 摘　　要

NOVELTY - A biomass graphene is prepared by adding solution containing potassium ion to lignin, stirring, filtering, water washing to obtain pre-treated lignin, adding aqueous solution of metal salt catalyst into pre-treated lignin in inert atmosphere, stirring, filtering and water washing to obtain solid product, and using two-step heat treatment method to heat solid product under inert atmosphere. The metal salt catalyst is iron salt, copper salt and/or nickel salt. USE - The method is used for preparing biomass graphene for preparing electrochemical energy storage and energy conversion device in battery (claimed) including lithium ion battery, lithium sulfur battery and fuel battery. ADVANTAGE - The product has high degree of graphitization, excellent conductivity, simple preparation technique, low cost and high cost performance.