“…1,8,9 This allows access to materials with a lower transition-metal oxidation state, such as Mn 2+ , to adjust electrochemical performance. Solid-state synthesis forms the most thermodynamically stable phases, whilst mechanochemical synthesis generates defects and amorphous species without heat treatment, 5,8 but its application is hindered in large-scale manufacturing purposes because of irreproducibility and impurities from the grinding media. 10 In this paper, we report a different approach to access low oxidation states of transition-metal cations in lithium niobate DRS materials, with the use of a reductive gas atmosphere during synthesis.…”