Scalable production of ultrathin Li-Sn-In alloy foil with interpenetrated skeleton for high-energy-density lithium metal batteries

Lithium (Li) metal holds great promise to be the ultimate anode owing to its high specific capacity and low redox potential . However, simultaneously addressing the challenges of uncontrollable dendrites growth, huge volume change, and poor processability is crucial for its practical application in next-generation high-energy-density batteries . Herein, a practical ultrathin (10 μm) Li-rich Li-Sn-In alloy (LSI) composite electrode with simultaneously optimized interphase and mechanical properties is fabricated through a scalable mechanical kneading process using Li and In 52 Sn 48 foils. The stable interpenetrated InLiSn skeleton in the electrode not only accommodates volume changes but also regulates Li stripping/plating, contributing to superior performances compared to that of pure Li metal electrode. Significantly, the LSI-20||LSI-20 symmetric cell, in which the LSI electrode is produced with 20 wt % In 52 Sn 48 alloy (LSI-20), exhibits stable cycling in carbonate-based electrolytes for 2700 h at 1 mA cm -2 and 1 mAh cm -2 . The NCM95||LSI-20 coin-type full cell with an ultrahigh loading cathode (∼18 mg cm -2 ) also reveals a high capacity retention of 89.2 % for 200 cycles at 0.5 C. More impressively, the NCM95||LSI-20 pouch cell with a low N/P capacity ratio of ∼ 2.0 delivers a high energy density of ∼ 495.5 Wh kg -1 at 0.2 C, and maintains 91.7 % capacity retention over 100 cycles, demonstrating the promising practical application potential of the LSI anode in the next-generation high-energy Li metal batteries (LMBs).