HESOZA · All-in-one solar rechargeable Zinc-air battery enabling direct storage of solar energy

As photovoltaics (PV) technology develops rapidly, solar energy conversion and storage devices such as solar rechargeable batteries are also becoming more viable to compensate for intermittent sunlight. Considering their working life, cost, energy density, safety and eco-friendliness, rechargeable Znair batteries (ZABs) are regarded as a promising candidate for next generation advanced energy devices. Solar rechargeable ZABs would effectively convert and store solar energy in one two-electrode battery, simplifying the configuration and decreasing the external energy loss. Yet, there are several major challenges to widespread adoption of solar rechargeable ZABs: (i) low efficiency due to lack of high performance photoactive electrode capable of light harvesting and energy storage, (ii) instability and low cycle life due to anode-electrolyte side reactions. This proposal will develop for the first-time ZABs with solar-charging capabilities through combinatorial designing of a bifunctional high entropy material (HEM) photocathode-catalyst, fabricating a gradient nanoporous fluorinated zinc-tin (FZT) anode and optimizing electrolyte composition. Such a configuration enables to decrease the charge overpotential of ZABs below the theoretical voltageof 1.65 V. More importantly, it directly stores solar-to-electrochemical energy. Therefore, the main goal of this proposal is to boost the efficiency and stability of solar rechargeable ZABs by taking advantages of HEM concept i.e., numerous active sites, sluggish diffusion, and enabling much improved plating/stripping cycling on FZT anode through a 2e/O2 process in nonalkaline aqueous electrolyte. HESOZAs achievements will make advancements on cutting edge direct solar-to-electrochemical energy storage in a simple two-electrode cell configuration that are pivotal to reach EUs environmental targets for a reliable and green energy transition at low-cost.