Gelatin-polyethylenimine composite as a functional binder for highly stable lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries with high specific capacity are expected to be a new generation of energy storage devices. However, the shuttle effect of lithium polysulfide makes it difficult to commercialize stable Li-S batteries. In this work, we designed a gelatin-polyethylenimine composite (GPC) as functional binder for Li-S batteries to improve the stability of electrode during discharge-charge process. GPC binder combines the dispersion and adhesion ability of gelatin, which keeps cathode homogeneous and stable during electrochemical reaction , and adsorption capability of PEI for polysulfide , which suppresses the “shuttling effect”. The result shows that GPC used as a binder remarkably enhanced cyclic performance of Li-S battery with good capacity retention of about 100% at current density of 1C (sulfur loading 1.5 mg cm −2 ) after 100 cycles. We believe that GPC would be a promising binder for highly stable Li-S batteries.