▎ 摘　　要

NOVELTY - Flexible lithium ion battery comprises cathode black phosphorus nano-graphene composition film with flexibility and strength, thickness of 2-200 mu , electrical conductivity of 200-5000 S/minute, 10-90wt%the black phosphorus nano-sheet content, 10-90 wt.% graphite content and cathode capacity is 100-800 mAh/g-1. USE - Used as Flexible lithium ion battery. ADVANTAGE - The cathode film is easy and simple to prepare, economical, has high capacity, excellent conductivity, has two-dimensional structure flexibility, high intensity, and solves the problem of bad conductivity and stability of black phosphorus, improves the capacity of lithium ion battery, cycle stability and energy density. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing composition film cathode, comprising synthesizing black phosphorus block by mineral assisted vapor transport method in water, using ultrasonic method for preparing black phosphorus nano sheet, dispersing black phosphorus and graphene in organic solvent, ultrasonic and vacuum filtering on the organic membrane, drying in vacuum, peeling the film from organic membrane to obtain the black nano-graphene composition film cathode.