The challenges and perspectives of developing solid-state electrolytes for rechargeable multivalent battery

From the perspective of future development trend, energy issues will always accompany with the human development process. The development of new batteries that are friendly to the environment has become a global trend. Safe solid-state electrolytes with high ionic conductivity, excellent electrochemical property, high mechanical/thermal stabilfity, and good electrolyte/electrode compatibility are believed the key components to the next-generation rechargeable batteries. Therefore, from the perspective of balancing both high energy density and intrinsic safety, all-solid-state ion batteries should be further developed, while a stable, nonflammable solid-state electrolyte should be designed and optimized to match it. This paper gives a comprehensive review on the recent progress in the solid-state electrolytes for multivalent-ion batteries, mainly for magnesium-ion, calcium-ion, zinc-ion, and aluminum-ion batteries. The key aspects of solid-state electrolytes are highlighted, including the synthesis process, physicochemical properties, and electrochemical performance. All-solid-state battery now is becoming the rising star since solid-state electrolyte solves most of the problems faced by the current lithium-ion batteries, allowing the best balance between battery life, safety, and cost.