A Cu-based electronically conducting metal–organic framework with π–d conjugation for cathode and anode modification in aqueous zinc-ion batteries

The commercial applications of aqueous rechargeable zinc-ion batteries (ZIBs) remain limited mainly owing to the low capacity storage efficiency and structural deformation of cathode materials, coupled with anode dendrite formation and side reactions that compromise battery performance. Herein, the electronically conductive metal-organic framework (EC-MOF) DDA-Cu was developed and used as the cathode for the first time in ZIBs. The electrode material showed an excellent initial discharge capacity of 249.6 mAh g −1 at 0.2 A g −1 . Notably, it also reached a effective capacity of 120 mAh g −1 after 175 cycles at an increased current density of 1 A g −1 . When used as an interface protective coating for zinc anodes, the uniform pore channels of DDA-Cu facilitated homogeneous zinc-ion deposition, which effectively suppressed dendrite growth and side reactions, typically a hydrogen evolution reaction (HER). Compared with bare zinc anodes, the Zn@DDA-Cu anode significantly extended battery lifespan, demonstrating stable cycling for over 3500 h at 0.5 mA cm −2 . Notably, the full battery with a Zn@DDA-Cu anode and a DDA-Cu cathode exhibited stable cycling for 100 cycles at 1 A g −1 , retaining a capacity of 185.5 mAh g −1 . This study provides an innovative strategy for the development of promising EC-MOFs for practical ZIB application.