Multi‐Group Polymer Coating on Zn Anode for High Overall Conversion Efficiency Photorechargeable Zinc‐Ion Batteries

Abstract The solar‐driven photorechargeable zinc‐ion batteries have emerged as a promising power solution for smart electronic devices and equipment. However, the subpar cyclic stability of the Zn anode remains a significant impediment to their practical application. Herein, poly(diethynylbenzene‐1,3,5‐triimine‐2,4,6‐trione) (PDPTT) was designed as a functional polymer coating of Zn. Theoretical calculations demonstrate that the PDPTT coating not only significantly homogenizes the electric field distribution on the Zn surface, but also promotes the ion‐accessible surface of Zn. With multiple N and C=O groups exhibiting strong adsorption energies, this polymer coating reduces the nucleation overpotential of Zn, alters the diffusion pathway of Zn 2+ at the anode interface, and decreases the corrosion current and hydrogen evolution current. Leveraging these advantages, Zn‐PDPTT//Zn‐PDPTT exhibits an exceptionally long cycling time (≥4300 h, 1 mA cm −2 ). Zn‐PDPTT//AC zinc‐ion hybrid capacitors can withstand 50,000 cycles at 5 A/g. Zn‐PDPTT//NVO zinc‐ion battery exhibits a faster charge storage rate, higher capacity, and excellent cycling stability. Coupling Zn‐PDPTT//NVO with high‐performance perovskite solar cells results in a 13.12 % overall conversion efficiency for the photorechargeable zinc‐ion battery, showcasing significant value in advancing the efficiency and upgrading conversion of renewable energy utilization.