Tuning bifunctional interface for advanced sulfide-based all-solid-state batteries

The development of high-performance sulfide electrolyte-based all-solid-state lithium-ion batteries (ASSLIBs) has been inhibited by problematic ionic transport and side reactions at the cathode interface, and their success is dependent on the functionalized interface upon charging and discharging. Despite recent progresses, it has proven challenging to design a favorable interface that can suppress the side reactions and enable smooth motion of Li + ions. Herein, a favorable Zr-based cathode interface is elaborately manipulated by the atomic layer deposition (ALD) for sulfide-based ASSLIBs. Flexile control over the Li sub-cycle during the preparation process is demonstrated to be crucial for achieving a robust cathode interface with a desirable Li + ionic conductivity. The ASSLIBs equipped with this functional interface exhibit excellent cycling stability and rate capability at room temperature (RT). Various electrochemical and spectroscopic characterizations reveal that the ionic conductive interface can significantly limit side reactions and induce a low polarization of the (de)intercalation toward cathode materials. The interfacial manipulation regarding ionic conductivity and structure realized by ALD provides a new strategy to achieve high-performance ASSLIBs. Ionic conductive and robust lithium zirconium oxides (LZO) are fabricated by a precisely controlled atomic layer deposition (ALD). The ALD-LZO film promotes to achieve a favorable cathode/sulfide electrolytes interface, leading to an excellent electrochemical performance for advanced all-solid-state batteries. • Bifunctional LZO interlayers are developed by ALD technique for the first time. • The ALD-LZO film possesses a very promising Li + ionic conductivity. • The ALD-LZO derived cathode interface is compatible with sulfide electrolytes. • Excellent battery performance can be achieved with the ALD-LZO modifying interface. • Multiple electrochemical and spectroscopic characterizations reveal the mechanism.