Tuning Solid Interfaces via Varying Electrolyte Distributions Enables High-Performance Solid-State Batteries

Solid/solid interface is the major challenge for high-performance solid-state batteries. Solid electrolytes (SEs) play a crucial role in the fabrication of effective interfaces in solid-state batteries. Herein, the electrolyte distribution with varied particle sizes is tuned to construct solid-state batteries with excellent performance at different operating temperatures. Solid-state batteries with the configuration S/L (small-sized SE in composite cathode and large-sized SE in electrolyte layer) show the best performance at room temperature (168 mA h g⁻¹ at 0.2 C, retention of 99%, 100 cycles) and −20 ℃ (89 mA h g⁻¹ at 0.05 C), while the configuration S/S displays better performance at elevated temperature. The superior performance of S/L battery is associated with faster lithium-ion dynamics due to the better solid/solid interface between active materials and electrolytes. Moreover, the inferior performance at 60 ℃ is caused by the formation of voids and cracks in the electrolyte layer during cycling. In contrast, the S/S battery delivers superior performance at elevated operating temperature because of the integrated structure. This work confirms that tailoring electrolyte size has significant effect on fabricating all-climate solid-state batteries.