Boosting the rate performance of all-solid-state batteries with a novel double layer solid electrolyte

When compared to traditional liquid electrolytes, solid electrolytes face significant challenges due to insufficient ionic conductivity and poor interfacial contact. To overcome these challenges, a cathode-supported double layer gradient structured solid polymer electrolyte membrane is developed. This innovative design enhances the wetting ability of the solid electrolyte on the cathode, leading to improved rate performance. Furthermore, the double layer solid electrolyte enhances mechanical strength, ensuring excellent cycling performance. As a result, the LiFePO 4 /Li solid state battery demonstrates superior battery performances, for instance, it can achieve a discharge capacity of 121 mAh g −1 at a current rate of 5C, with a capacity retention of 99 % after 380 cycles. This work offers a promising strategy for further enhancing the performance of all solid-state batteries.