Solvent–Mediated Cathode Prelithiation for Durable, High‐Energy Lithium‐Ion Batteries

Abstract Lithium‐ion batteries (LIBs) with silicon (Si)‐based anode are widely regarded as the next‐generation LIBs due to their high energy density. However, the significant initial lithium (Li) loss considerably reduces the achievable specific energy. Consequently, prelithiation has emerged as a promising strategy to enhance the deliverable energy of LIBs. Yet, existing prelithiation strategies often lead to material or electrode damage due to nonsynchronous or overlithiation, thereby posing a significant challenge to their practical implementation. Herein, a controllable contact prelithiation strategy is proposed for LiCoO 2 cathodes employed fluoroethylene carbonate (FEC) as the medium. The low‐concentration Li + ‐conductive medium, naturally generated through the reaction between FEC and metallic Li, enables the spontaneous and synchronous prelithiation of active cathode particles throughout the electrode. FEC‐mediated prelithiation not only compensates for active Li but also fosters enhanced interphase stability of the cathode material. Ah‐level laminated LiCoO 2 ||Si/C pouch cells with FEC‐mediated cathode prelithiation exhibited ≈15% and ≈11% enhancement in energy density and cyclic stability, respectively (421.8 Wh kg −1 at 0.1 C , 92.4% capacity retention for 200 cycles at 0.2 C ). This contact prelithiation approach offers a general and industry‐adaptable method for achieving controllable prelithiation, thereby providing a feasible pathway toward the realization of practical high energy density LIBs).