Stable and Low‐Pressure Anode‐Free All‐Solid‐State Li–S Batteries Enabled by Reaction‐Derived Nanocrystalline‐Amorphous Li 2 S Cathodes and Deformable Sodium Current Collectors
Qi Zhang, Rui Yang, Zhiwei Ni, Zhengran Wang, Baojuan Xi, Shenglin Xiong, Aimin Zhang, Jinkui FengABSTRACT
Anode‐free all‐solid‐state Li–S batteries (ASSLSBs) are promising for high‐energy‐density storage, but their development is hindered by sluggish Li 2 S activation and unstable solid–solid interfaces, especially under low stack pressure. Here we report a low‐pressure anode‐free ASSLSB enabled by a solid‐state in situ reaction‐derived nanocrystalline‐amorphous Li 2 S cathode and a deformable Na current collector. During short‐term high‐energy ball milling, PI 3 reacts with Li 2 S to generate LiI and amorphous thiophosphate species around nanocrystalline Li 2 S domains, forming a reaction‐derived ion‐conductive framework. Meanwhile, the Na current collector maintains intimate contact with the sulfide electrolyte even under limited external pressure, while the mitigated volume variation of Li 2 S and amorphous interfacial framework jointly stabilize the solid–solid interfaces during cycling. Consequently, the optimized Li 2 S‐PI 3 8% full cell exhibits a capacity retention of approximately 100% after 200 cycles at 0.5 C under a stacking pressure of 4 MPa. Under the same external pressure, the cell further exhibits a capacity retention of 89.71% after 400 cycles at 0.2 C. Remarkably, even under an external pressure as low as 1 MPa, the full cell maintains 70.54% capacity retention after 300 cycles, underscoring its robust cycling stability under low‐external‐pressure conditions.