Construction of Co3O4@NiMoO4 core-shell structure for high-current density photo-assisted lithium-oxygen battery.

Based on the measured strategy of photo-assisted promotion of the battery performance of LOBs, we designed a Co 3 O 4 @NiMoO 4 cathode with a core–shell structure. At a high current density of 1.0 mA cm−2 and a capacity of 0.5 mAh cm−2, Co 3 O 4 @NiMoO 4 , as the cathode of the photo-assisted LOBs, has the first charge and discharge overpotential of 1.01 V and a cycle life of 164 times with illumination，which is obviously better than without illumination. [Display omitted] • Co 3 O 4 @NiMoO 4 with core–shell structure was synthesized by a two-step hydrothermal method. • Co 3 O 4 @NiMoO 4 shows good optical and electrochemical properties, due to the construction of core–shell structures. • The decomposition of Li 2 O 2 during the discharge process was facilitated by photo assistance. • Co 3 O 4 @NiMoO 4 with illumination shows better cycling stability and rate capability at high current density. Lithium-oxygen batteries (LOBs) are regarded as the most potential energy storage systems for the next generation due to their exceptionally high theoretical energy density. However, the discharge product (Li 2 O 2) results in significant overpotentials during charging and discharging, which severely limits the application of LOBs. In this work, Co 3 O 4 @NiMoO 4 core–shell structures were prepared by a secondary hydrothermal method and used as a photo-assisted LOB cathode. The core–shell structure not only enhances light absorption and conductivity, facilitating the separation of photoelectrons and holes, but also provides additional reaction sites for the OER and ORR. It has a low charging/discharging overpotential of 1.01 V and can operate stably for 164 cycles (at the current density of 1.0 mA cm−2 and the capacity of 0.5 mAh cm−2) with good multiplicative performance with illumination. This paper is an effective and valuable reference for the subsequent development of cathode catalysts for photo-assisted LOBs. [ABSTRACT FROM AUTHOR]