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.