Performance of lithium sulfur batteries using porous raney nickel as sulfur immobilizer

A new electric and porous material named raney nickel(RNi) was proposed as S immobilizer for lithium sulfur batteries. The solvent method, grinding high temperature method and ball milling high temperature method were introduced to prepare S/RNi composite. The results show S/RNi composite exhibits the best electrochemical performance under solvent method. The pretreated raney nickel is a spongy and conductive porous structure with a pore size distribution between 12.5 nm and 50 nm. SEM and XRD demonstrate that S/RNi composite has good pore structure under solvent method. Elemental sulfur grains are evenly distributed and in close contact in the pore structure of raney nickel with a small size. S/RNi cathode under solvent method performs an initial discharge specific capacity of 1 479 mAh/g, and still remains a discharge specific capacity of 765 mAh/g after 200 cycles with a high coulombic efficiency of about 99%. The cycling performance of S/RNi composite under solvent method is still better than that of conventional S/C composite. The cyclic stability and high rate performance of S/RNi cathode under solvent method are contributed to the conductivity and the chemical adsorption on polysulfides of raney nickel.