Controlling the Intercalation Chemistry to Design High-Performance Dual-Salt Hybrid Rechargeable Batteries

摘要

We have conducted extensive theoretical and experimental investigations to unravel the origin of the electrochemical properties of hybrid Mg~(2+)/Li~+ rechargeable batteries at the atomistic and macroscopic levels. By revealing the thermodynamics of Mg~(2+) and Li~+ co-insertion into the Mo_6S_8 cathode host using density functional theory calculations, we show that there is a threshold Li~+ activity for the pristine Mo_6S_8 cathode to prefer lithiation instead of magnesiation. By precisely controlling the insertion chemistry using a dual-salt electrolyte, we have enabled ultrafast discharge of our battery by achieving 93.6% capacity retention at 20 C and 87.5% at 30 C, respectively, at room temperature.