Light-induced Li extraction from LiMn 2 O 4 /TiO 2 in a water-in-salt electrolyte for photo-rechargeable batteries.

Photocharging of high-potential spinel LiMn 2 O 4 is demonstrated by using a water-in-salt electrolyte and TiO 2 nanoparticles. In a developed half-cell system with an electron acceptor, Li extraction from LiMn 2 O 4 proceeds under the illumination of UV-visible light at an estimated rate of ∼23 mA g -1 . This work paves the way for high-potential cathode materials in photo-rechargeable batteries.