A reversible oxygen redox reaction in bulk-type all-solid-state batteries

• Published in: Science advances 2020-06, Vol.6 (25), p.eaax7236-eaax7236
• Main Authors: Nagao, Kenji, Nagata, Yuka, Sakuda, Atsushi, Hayashi, Akitoshi, Deguchi, Minako, Hotehama, Chie, Tsukasaki, Hirofumi, Mori, Shigeo, Orikasa, Yuki, Yamamoto, Kentaro, Uchimoto, Yoshiharu, Tatsumisago, Masahiro
• Format: Article
• Language: English
• Subjects: Electrochemistry; Physics; SciAdv r-articles
• ISSN: 2375-2548; 2375-2548
• DOI: 10.1126/sciadv.aax7236

A high-capacity positive electrode active material Li 2 RuO 3 -Li 2 SO 4 for all-solid-state batteries was developed. An all-solid-state lithium battery using inorganic solid electrolytes requires safety assurance and improved energy density, both of which are issues in large-scale applications of lithium-ion batteries. Utilization of high-capacity lithium-excess electrode materials is effective for the further increase in energy density. However, they have never been applied to all-solid-state batteries. Operational difficulty of all-solid-state batteries using them generally lies in the construction of the electrode-electrolyte interface. By the amorphization of Li 2 RuO 3 as a lithium-excess model material with Li 2 SO 4 , here, we have first demonstrated a reversible oxygen redox reaction in all-solid-state batteries. Amorphous nature of the Li 2 RuO 3 -Li 2 SO 4 matrix enables inclusion of active material with high conductivity and ductility for achieving favorable interfaces with charge transfer capabilities, leading to the stable operation of all-solid-state batteries.