Preparation of PTFE/Ketjen Black-C flexible composites by high energy ball milling method and its electrochemical application

A lithium-sulfur battery interlayer flexible material composed of precursor carbon material was prepared by multi-step temperature carbonization process with lotus-leaf as the raw material, ball-milling blending and vacuum filtrating precursor carbon material, Ketjen Black (KB) as well as polytetrafluo-roethylene (PTFE) at the mass ratio of 2:2:3. The porous structure of PTFE/KB-C composites can not only provide a large number of three-phase reaction sites for further reduction of higher-order sulfide Li₂S_n (4≤n≤8), but also suppress the shuttle effect of soluble polysulphide by good multilayer porous chemical adsorption effect of PTFE/KB-C composites. The lithium-sulfur battery capacity property test characterization of interlayer with pure sulfur as the anode material shows that initial discharge specific capacity is as high as 1350 mAh·g^-1 at 1.0 C rate (current density is 1675 mA·g^-1) and remains 960 mAh·g^-1 after 100 charge-discharge cycles without nitric acid lithium additives. Coulomb efficiency above 95% is achieved, demonstrating high performance of cycle stability.