Generalized Interphase Design for Stabilized Li/Inorganic Electrolyte Interfaces

Abstract All‐solid‐state Li metal batteries (ASSLMBs) using inorganic solid‐state electrolytes (ISEs) are considered promising energy storage technologies owing to their intrinsic safety and high energy density. Nevertheless, one critical challenge confronting ASSLMBs is the inability of the ISEs to prevent Li dendrite growth, which has not yet been fully addressed. Herein, general design principles of artificial solid electrolyte interphases (ASEI) for suppressing Li dendrites in ASSLMBs are proposed by systematically exploring the formation mechanism of Li dendrites. Subsequently, a tailored LiF‐Li 3 N ASEI is constructed to inspect the Li‐dendrite‐free design principles. The LiF‐Li 3 N modified Li (LFN‐Li) can effectively inhibit the side reactions and suppress the growth of Li dendrites, thus boosting the critical current densities of Li 10 GeP 2 S 12 (LGPS) to a record‐high value of 3.4 mA cm −2 . Furthermore, the LFN‐Li/LGPS/LFN‐Li can cycle stably for over 5000 h at 0.2 mA cm −2 . Crucially, the versatility of the designed ASEI is highlighted as it ensures outstanding long‐term stability in symmetric cells featuring oxide Li 1.3 Al 0.3 Ti 1.7 (PO) 3 or halide Li 2 ZrCl 6 ISEs. As a result, the ASEI enables LiNi 0.8 Mn 0.1 Co 0.1 O 2 /LGPS/LFN‐Li and FeS 2 /LGPS/LFN‐Li cells to achieve high discharge‐specific capacities and desirable cyclic stability at room temperature. The generalized ASEI design principles rationalize the development of high‐energy ASSLBMs.