To mitigate the challenges associated with interfacial degradation caused by detrimental secondary reactions, the application of a protective coating on the surface of cathode particles is regarded as a productive mitigation strategy .Considerable amount of research has been performed to explore suitable coating materials, such as oxides, e.g., ZrO2 , HfO2 [8], Li2ZrO3 and, LiNbO3 , and phosphates, e.g., Li3PO4 , and LiZr2(PO4)3 . High-voltage cathodes coated with metal oxides and phosphates show improved specific capacity, and capacity retention compared with uncoated counterparts in thiophosphate-based SSBs. However, these coating additives exhibit either limited Li-ion conductivity (<10 -4 S/cm), or insufficient stability against high-voltage cathode.