LiNbO3-coated LiNi0.7Co0.1Mn0.2O2 and chlorine-rich argyrodite enabling high-performance solid-state batteries under different temperatures

Surface modification of high voltage cathodes can enhance the electrochemical performance of solid-state batteries (SSBs) employing sulfide electrolytes. LiNbO3-coating is a common method, however, the role and potential of such coating on the high-nickel cathode is still under-discovered especially during extended cycling at different rates in wide temperature ranges. Herein, we carry out in-depth study of LiNbO3 coating enabled chlorine-rich argyrodite-based SSBs using LiNi0.7Co0.1Mn0.2O2 (NCM712) cathode at various C-rate (0.1, 0.5, and 1 C) and wide temperatures (-20 degrees C, 25 degrees C (RT), and 60 degrees C). The LNO@NCM712 electrode delivers initial discharge capacities of 80.9 and 138.9 mAh/g at 5 C under RT and 60 degrees C respectively with better capacity retentions of 87.5% and 88% after 600 and 300 cycles than that of the NCM712 electrode. Moreover, the LNO@NCM712 electrode also shows better electrochemical behavior than the pristine electrode under deep-freezing temperature (-20 degrees C). The improved battery performance of the LNO@NCM712 electrode is supported by the resistance changes between the cathode and solid electrolyte revealed by EIS and the structural evolution of active materials unraveled by TEM. This study offers a deep insight into the influence of the modification layer for the performance of SSBs and guidance of design strategy for cathode modification.

Automated summary

The study investigates the enhancement of solid-state battery performance by surface modification of high-voltage cathodes using LiNbO3 coating. The LNO@NCM712 electrode shows improved cyclic performance and lower resistance changes at different rates and temperatures, providing insight into the influence of modification layers on SSB performance and guidance for cathode modification design strategy.