多孔兰尼镍作单质硫载体的锂硫电池性能

提出以导电多孔兰尼镍（RNi）为锂硫电池中单质S的新载体材料，探究了S/RNi复合材料在溶剂法、研磨高温法及球磨高温法下的电化学性能差异。结果表明，溶剂法制备的S/RNi复合材料的电化学性能最好。预处理后的RNi为海绵状的导电多孔结构，孔径分布在12.5~50 nm之间。SEM和XRD表明，溶剂法制备的S/RNi复合材料具备良好的孔结构，单质S颗粒较小，均匀分布在深层孔结构中，S与RNi充分接触。其首次放电比容量达到1 479 mAh/g，经过200次充放电循环后放电比容量保持在765 mAh/g，库伦效率约为99%。其循环性能也优于传统S/C复合材料。溶剂法制备的S/RNi复合材料的循环稳定性和高倍率性能得益于RNi的导电性及对单质S的物理和化学吸附。

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.