A Photo-rechargeable Aqueous Zinc–Tellurium Battery Enabled by the Janus-Jointed Perovskite/Te Photocathode

The combination of photo-driven self-powered supplies and energy storage systems is considered as a promising candidate to solve the global energy dilemma. The photo-absorber and the energy storage material are integrated into the photocathode to effectively achieve a high-energy and high-efficiency energy system. In this work, we report the customized Janus-jointed photocathode design (integrating with highly efficient halide perovskite and tellurium composite electrode) and introduce it into the aqueous zinc–tellurium battery. The well-matched energy level of the Janus-jointed photocathode ensures the conversion of the photoenergy into electrical energy by transferring the photoexcited charge between each. As expected, in the photo-assisted recharging model, the decreased 0.1 V charge voltage and the extra 362 mA h g–1 at 100 mA g–1 demonstrated the significant merits of saving energy for such a photo-rechargeable Zn–Te (PRZT) battery. When the current density is 1000 mA g–1, the specific capacity of the prepared photocathode is 83% higher than that under dark conditions. More importantly, the photogenerated charge by the perovskite under light illumination could also directly photocharge the battery with no external current, indicating the self-powering traits. The rational design in this work is believed to provide a sustainable mode for efficient charging of the aqueous PRZT battery.