Locking Cascade Reaction Path of Bulk Degradation Achieves Stable Unmodified Solid Electrolyte

The severe structural degradation of solid electrolytes induced by the complex parasitic reactions associated with cathode materials has hampered the practical application of solid-state batteries. However, the degradation process of solid electrolytes influenced by the cathode is not well understood. Herein, we discover that electrolyte degradation is strongly associated with bulk decomposition, unlike conventional insight into only the interface-catalyzed decomposition. The highly acidic HTFSI produced by the triggering event can induce subsequent Ni dissolution and bulk decomposition of solid electrolytes through cascade reaction of bulk decomposition behavior, leading to a continuous decline in the electrochemical performance of solid-state batteries. By introducing a dissolution-retardant active structure onto the Ni-rich electrode, it mitigates the bulk cascade reaction and maintains the energy density. The designed electrode demonstrated an impressive 84% retention of maximum reversible capacity after 2000 cycles at 2C under 4.3 V. This study opens a new avenue in the design of next-generation long-life batteries.