Manipulating surface reactions in lithium–sulphur batteries using hybrid anode structures

Lithium–sulphur batteries have high theoretical energy density and potentially low cost, but significant challenges such as severe capacity degradation prevent its widespread adoption. Here we report a new design of lithium–sulphur battery using electrically connected graphite and lithium metal as a hybrid anode to control undesirable surface reactions on lithium. Lithiated graphite placed in front of the lithium metal functions as an artificial, self-regulated solid electrolyte interface layer to actively control the electrochemical reactions and minimize the deleterious side reactions, leading to significant performance improvements. Lithium–sulphur cells incorporating this hybrid anodes deliver capacities of >800 mAh g −1 for 400 cycles at a high rate of 1,737 mA g −1 , with only 11% capacity fade and a Coulombic efficiency >99%. This simple hybrid concept may also provide scientific strategies for protecting metal anodes in other energy-storage devices. Operation of lithium–sulphur batteries suffers from uncontrolled lithium polysulphide formation and corrosion at the anode. Huang et al. design an integrated anode structure composed of electrically connected graphite and lithium metal, which alleviates the problems and leads to high battery performance.