Nano Silicon Anode without Electrolyte Adding for Sulfide‐Based All‐Solid‐State Lithium‐Ion Batteries

All-solid-state lithium-ion batteries (ASSLBs) employing silicon (Si) anode and sulfide electrolyte attract much attention, since they can achieve both high energy density and safety. For large-scale application, sheet-type Si anode matching sulfide based ASSLBs is preferred. Here, a LiAlO2 layer coated Si (Si@LiAlO2 ) is reported for sheet-type electrode. This electrode employs conventional slurry coating methods without adding any sulfide electrolyte. The effect of LiAlO2 coating on the electrochemical performance and morphology evolution of Si electrode is investigated. Since the high mechanical strength and ionic conductivity of LiAlO2 layer can sufficiently relieve the huge expansion of Si and promote the Li+ diffusion, the electrochemical performance is significantly enhanced. The Si@LiAlO2 electrodes deliver high coulombic efficiency exceeding 80% and hold considerable specific capacity of 1205 mAh g-1 (150 cycles, 0.33 C). The Si@LiAlO2 | LiNi0.83 Co0.11 Mn0.06 O2 full-cells exhibit a high reversible capacity of 147 mAh g-1 (0.28 mA cm-2 ) and a considerable capacity retention of 80.2% (62 cycles, 2.8 mA cm-2 ). This work demonstrates promising practicability and provides a new route for the scalable preparation of Si electrode sheets for ASSLBs with extended lifespan.