Solvation Deshielding Chemistry in γ‐Valerolactone‐Based Electrolytes Enables Fast Interfacial Charge Transfer Kinetics in Low‐Temperature Lithium‐Ion Capacitors

Abstract

Lithium‐ion capacitors (LICs) suffer from severely deteriorated energy output and sluggish kinetics under deep subzero conditions, primarily due to strong Li + ‐solvent shielding interactions and high desolvation barriers in conventional electrolytes. Herein, a solvation deshielding chemistry is proposed to reconstruct the solvation sheath using a moderately coordinating γ ‐valerolactone (GVL)‐based electrolyte system, which effectively weakens Li + ‐solvent interactions, enhances anion accessibility, and accelerates interfacial charge‐transfer kinetics. The engineered electrolyte maintains fast ion‐transport capability across a broad temperature window while inducing the formation of a robust inorganic‐dominated interphase that lowers Li + migration resistance at electrode interfaces. This enables the hard carbon anode to deliver a high capacity of 252 mAh g −1 at −20 °C, outperforming most reported carbon‐based LIC anodes under low‐temperature conditions. Meanwhile, the assembled all‐carbon LIC achieves a high energy density of 121 Wh kg −1 along with a maximum power density of 13.3 kW kg −1 at −20 °C, confirming the simultaneous realization of high energy and high power under subzero conditions. Even at −40 °C, it still delivers a remarkable energy density of 106.8 Wh kg −1 . This work demonstrates that rational deshielding of solvation structure provides a viable pathway to overcome the intrinsic kinetic limitations of LICs under extremely low‐temperature conditions.