Li 3 BO 3 –Li 2 CO 3 : Rationally Designed Buffering Phase for Sulfide All-Solid-State Li-Ion Batteries

Most inorganic solid electrolytes (SEs) suffer from narrow intrinsic electrochemical windows and incompatibility with electrode materials, which results in the below par electrochemical performances of all-solid-state Li-ion or Li batteries (ASLBs). Unfortunately, in-depth understanding on the interfacial evolution and interfacial engineering via scalable protocols for ASLBs to mitigate these issues are at an infancy stage. Herein, we report on rationally designed Li 3 BO 3 –Li 2 CO 3 (LBO-LCO or Li 3– x B 1– x C x O 3 (LBCO)) coatings for LiCoO 2 in ASLBs employing sulfide SE of Li 6 PS 5 Cl. The new aqueous-solution-based LBO-coating protocol allows us to convert the surface impurity on LiCoO 2 and Li 2 CO 3, into highly Li + -conductive LBCO layers (6.0 × 10 –7 S cm –1 at 30 °C for LBCO vs 1.4 × 10 –9 S cm –1 at 100 °C for Li 2 CO 3 or 1.4 × 10 –9 S cm –1 at 30 °C for LBO), which also…