Ni-Bis(dithiolene) Coordination Enhanced Dual-Functional Covalent Organic Frameworks for both Cathodic Zn Storage and Anodic Zinc Deposition Control in Aqueous Zn-Ion Batteries.

In response to the increasing demand for sustainable energy storage solutions, aqueous zinc-ion batteries (AZIBs) have garnered significant attention for their high safety, low cost, and environmental friendliness. However, two major challenges to battery stability persist: developing efficient cathode materials and addressing zinc dendrite formation. Here, we report a dual-functional covalent organic framework (COF), named Ni-DAPTO, designed to improve both Zn storage on the cathode and zinc deposition kinetics on the anode. The incorporation of Ni coordination centers achieves an expected low energy gap, enhancing the intrinsic conductivity, while selectively guiding uniform Zn deposition. As a result, the Ni-DAPTO cathode demonstrated superior cycling stability and rate performance, retaining a specific capacity of 127.0 and 119.7 mAh g at 0.5 and 10.0 A g, respectively after 10 000 cycles. Besides, when employed as artificial solid electrolyte interphase (SEI), Ni-DAPTO can improve zinc utilization and inhibit dendrite formation. The full AZIBs assembled with Ni-DAPTO cathodes and Ni-DAPTO modified Zn anodes deliver a discharge capacity of 100.9 mAh g after 1000 cycles at a current density of 5.0 A g. These findings suggest that multifunctional COFs hold great potential for advancing high-performance and long-lasting aqueous secondary batteries.