Recent advances of non-lithium metal anode materials for solid-state lithium-ion batteries

Abstract

The lithium-ion battery has the advantages of high energy density, long cycle life, small occupied volume, and high discharge voltage, which significantly promotes the development of portable electronic devices and electric vehicles. However, the accompanying safety issues have also aroused great concern. Solid-state lithium-ion batteries using solid-state electrolytes are considered next-generation advanced energy devices which are expected to fundamentally solve the safety problems of conventional lithium-ion batteries. At present, lithium metal is mainly used as the anode material in the research of solid-state lithium-ion batteries. However, during battery cycling, the lithium dendrites produced on the surface of lithium metal will also penetrate the solid electrolyte, threatening the battery's safety. Therefore, it is necessary to develop non-lithium metal anodes for solid-state batteries. This review focuses on the research progress of lithium-free anode materials in solid-state batteries, including C, Si, Sn, Bi, Sb, metal hydrides, and lithium titanate (Li₄Ti₅O₁₂). The effects of the size and structure of active materials, the use of a binder, the selection of solid electrolytes, and the manufacturing process on the electrochemical performance of the electrode are discussed in detail. The lithium storage mechanism, existing problems, improvement strategies, and application prospects of anode materials are summarized. By discussing the use of these active materials and their existing problems, this review provides a comprehensive insight into the application of non-lithium metal anode materials.