Beschreibung:
<jats:title>Abstract</jats:title><jats:p>All‐solid‐state batteries attract significant attention owing to their potential to realize an energy storage system with high safety and energy density. In this paper, a mechanochemical synthesis of novel amorphous positive electrode materials of the Ni‐rich LiNi<jats:sub>1−</jats:sub><jats:italic><jats:sub>x</jats:sub></jats:italic><jats:sub>−</jats:sub><jats:italic><jats:sub>y</jats:sub></jats:italic>Mn<jats:italic><jats:sub>x</jats:sub></jats:italic>Co<jats:italic><jats:sub>y</jats:sub></jats:italic>O<jats:sub>2</jats:sub> (NMC)–Li<jats:sub>2</jats:sub>SO<jats:sub>4</jats:sub> system suitable for oxide‐type all‐solid‐state batteries is reported. Through the mechanochemical treatment with Li<jats:sub>2</jats:sub>SO<jats:sub>4</jats:sub>, excellent formabilities of the electrode materials as those of ductile solid electrolytes are obtained. Owing to the deformability of the active material, a good electrode/electrolyte interface is provided simply by pressing at room temperature. In all‐oxide solid‐state cells using 80NMCs·20Li<jats:sub>2</jats:sub>SO<jats:sub>4</jats:sub> (mol%) positive electrode materials, the cell capacity increases with the Ni content in the NMC. The all‐solid‐state cell using the 80NMC811·20Li<jats:sub>2</jats:sub>SO<jats:sub>4</jats:sub> positive electrode active material exhibits a high capacity larger than 250 mAh g<jats:sup>−1</jats:sup> in a voltage range of 1.6–4.8 V versus Li at 100 °C. Furthermore, bulk‐type all‐oxide solid‐state batteries (Li<jats:sub>4</jats:sub>Ti<jats:sub>5</jats:sub>O<jats:sub>12</jats:sub>/80NMC532·20Li<jats:sub>2</jats:sub>SO<jats:sub>4</jats:sub> (mol%)) successfully function as secondary batteries with excellent cycle performances.</jats:p>