Solid Electrolytes for All-Solid-State Batteries

All-solid state lithium-ion batteries (ASSBs) have emerged as attractive alternatives to conventional liquid electrolyte cells for electrochemical energy storage, owing to their anticipated enhanced safety and higher energy densities. ASSBs are founded on high performance fast-ion conducting solid electrolytes, where the search for improved materials hinges on understanding their intrinsic nature and gaining comprehensive knowledge of the factors that dictate facile Li-ion transport. In turn, incorporating them into high functional ASSBs relies on mastering the interface of the solid electrolyte with the electrode materials.<br/> <br/>These topics will be the focus of the presentation based on recent findings in our laboratory. Our correlation of structure with ionic conductivity in a range of newly developed fast ion Li conductors helps understand how cation disorder and a frustrated energy landscape impacts conductivity and activation energy. These considerations lead to exciting new classes of fast-ion conductors, including new argyrodite fast-ion conducting iodides and lithium metal halides. Promising all solid-state Li-ion batteries utilize “bare” NCM-type, Ni-rich lithium metal oxide cathodes coupled with high voltage-stable solid-state electrolytes. Low-resistance “clean” solid-solid interfaces enable room temperature cells with capacities close to their liquid Li-ion counterparts at practical discharge rates over very long-term cycling.