Deep insight of interfacial stability of LiNi_0.7Co_0.1Mn_0.2O₂-based all-solid-state battery with superior performances

Chlorine-rich argyrodite Li_5.5PS_4.5Cl_1.5 with low-cost and high ionic conductivity displays great potential as a solid electrolyte for solid-state battery. However, poor compatibility with bare high-voltage cathode limits its applications. Here, the Li₂ZrO₃ coating and Li₃InCl₆ isolating layer strategy are employed to mitigate the interfacial instability between Li_5.5PS_4.5Cl_1.5 electrolytes and LiNi_0.7Co_0.1Mn_0.2O₂ materials, respectively. A diversified combination of two strategies is applied to construct all-solid-state batteries with a long lifespan and high energy density. Electrochemical performance results indicate that introducing Li₃InCl₆ electrolyte in the cathode mixture yields high discharge capacities at beginning and then suffers rapid capacity degradation during extended cycling. In contrast, the assembled Li₂ZrO₃@LiNi_0.7Co_0.1Mn_0.2O₂/Li_5.5PS_4.5Cl_1.5/Li–In battery delivers slightly lower capacities and superior capacity retention. Multiple characterization methods are employed to unravel the mechanism behind battery performance differences. The poor cycle performance of Li₃InCl₆-involved solid-state battery configurations is partially associated with the decomposition of Li₃InCl₆ in the cathode mixture. The Li₂ZrO₃ coating layer mitigates the side reaction between LiNi_0.7Co_0.1Mn_0.2O₂ and Li₃InCl₆, resulting in enhanced capacities and improved cyclability. Furthermore, the interfacial instability between Li₃InCl₆ and Li_5.5PS_4.5Cl_1.5 electrolytes leads to the poor cycling performance of batteries containing the Li₃InCl₆/Li_5.5PS_4.5Cl_1.5 bilayer structure. This work offers a comprehensive guide for designing high-performances all-solid-state lithium batteries.