The Marriage of Solid-State Electrolyte and Safe Lithium Metal Anodes in a Working Battery

Abstract

Li metal is extensively focused due to its ultrahigh theoretical capacity (3860 mAh g−1, 10 times higher than that of graphite) and the most negative electrochemical potential (−3.040 V versus standard hydrogen electrode). Solid-state electrolyte exhibits enhanced safety relative to non-aqueous electrolyte. Therefore, the marriage of Li metal and solid-state electrolyte is expected to inherit the merits of both. However, the competitive solid-state lithium metal batteries encounter formidable challenges, including dendrite issues and poor solid-solid contact. Investigating the interdisciplinary issues of solid-state electrolyte and Li metal in integrated cells is necessary to realize the efficient and safe solid-state lithium metal batteries. This talk focuses on the energy chemistry issues generated from the marriage of Li metal and solid-state electrolyte, instead of their respective problems. Firstly, the issues generated from the marriage of lithium metal anode and solid-state electrolyte. Specific attentions are paid to the large interfacial resistance, uncontrolled dendrite growth, and low operation current/capacity. The primarily understanding the ionic channels in the composite electrolyte and space charge layers in the interfacial region are also included. Based on these dilemmas and working principles, emerging strategies to render solid-state lithium metal batteries are introduced. Finally, the general conclusion and perspective on the current limitations and recommended research of solid-state lithium metal batteries are presented.