Stable cycling of high-capacity red phosphorus/carbon composite anode in all-solid-state lithium-ion batteries

Using the Li metal anode in all-solid-state batteries (ASSBs) is far more challenging than initially envisioned owing to poor thermodynamic stability against solid electrolytes. Therefore, it is imperative to develop Li-ion anode alternatives for the future practical implementation of high-energy ASSBs. Here, for the first time, we demonstrate the stable cycling of red phosphorus (P)-carbon composite as a low-cost and high-capacity anode in sulfide electrolyte-based ASSBs. By loading subnanometer-scaled red P clusters in the micropores of a commercial activated carbon (AC), the electrically insulating red P can be fully activated and operable in room-temperature ASSBs. Benefiting from its medium lithiation potential and fast Li+ diffusion capability, the resultant P@AC electrode enables a record-high current density of over 18 mA cm−2 without Li dendrite formation in a symmetric cell. In a half cell, the P@AC material with a red P content of 53 wt% can deliver a high first delithiation capacity of 1438 mAh g−1 at 0.2 A g−1 and a decent capacity retention of 66.9 % after 400 cycles (running time of over 180 days). When paired with a LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode, the P@AC||NCM811 full cell achieves an initial areal capacity of 2.98 mAh cm−2 and enables stable cycling over 200 cycles. This work demonstrates that the red P-carbon composite is one promising Li-ion anode candidate for long-life and high-loading ASSBs with sulfide electrolytes.