High-Performance Li-Se Batteries Enabled Via All-in-One Designed Cathode

As an alternative to Li-S battery, a Li-Se battery is promising due to its high volumetric energy density. However, practical applications have been limited by complex fabrication and undesirable electrochemical process during charge-discharge which leads to poor cycling performance and low rate capability. To overcome these obstacles, we demonstrate a new design of “all-in-one” Se cathode, which is a one-piece body combined with a cathode and a solid polymer electrolyte. It is simply prepared by electrodeposition of Se on Ni-foam and subsequent coating of the solid polymer electrolyte without using any binders or conductive additives. All-in-one Se cathode can provide facile manufacturing process, prohibit undesirable electrochemical reaction, enhance ion pathway, and secure safety from advantages of solid polymer electrolyte. Li-Se batteries assembled with all-in-one Se cathode and Li-metal anode exhibited highly stable performance with a low capacity decay of 0.003% per cycle at 1 C over 3000 cycles.