Latent solvent‐induced inorganic‐rich interfacial chemistry to achieve stable potassium‐ion batteries in low‐concentration electrolyte

Low‐concentration electrolytes (LCEs) have attracted great attention due to their cost effectiveness and low viscosity, but suffer undesired organic‐rich interfacial chemistry and poor oxidative stability. Herein, a unique latent solvent, 1,2‐dibutoxyethane (DBE), is proposed to manipulate the anion‐reinforced solvation sheath and construct a robust inorganic‐rich interface in a 0.5 M electrolyte. This unique solvation structure reduces the desolvation energy, facilitating rapid interfacial kinetics and K+ intercalation in graphite. Additionally, enhanced anion‐cation interactions promote the formation of a thin and robust interfacial layer with excellent cycling performance of potassium‐ion batteries (PIBs). Graphite||perylene‐3,4,9,10‐tetracarboxylic dianhydride full cell exhibits a good capacity retention of 80.3% after 300 cycles, and delivers a high discharge capacity of 131.3 mAh g‐1 even at 500 mA g‐1. This study demonstrates the feasibility of latent solvent‐optimized electrolyte engineering, providing a pathway of superior electrochemical energy storage in PIBs.