Multi-Active Site Zinc-Based Metal-Organic Frameworks-Interlinked Carbon: A High-Performance Cathode for Rechargeable Aqueous Zinc-Ion Batteries

Abstract

Aqueous zinc-ion batteries (AZIBs) have been attracting a lot of interest for energy storage applications because of their individual advantages such as high energy density, environmental friendliness and safety. Nevertheless, progress in the development of high-performance cathodes is still limited by poor reversibility and slow Zn²⁺ diffusion dynamics, which result in insufficient rate performance and low specific capacity. In this article, nano-carbon black (VXC-72R/C) is composited with zinc-based metal-organic framework (Zn-MOF) and used as the cathode for high-performance AZIBs. The constructed Zn-MOF@C framework exhibits a maximum specific capacity of approximately 189.57 mA h g⁻¹ at a current density of 500 mA g⁻¹, and retains about 84.9% capacity retention after 2000 continuous cycles, with no significant loss in coulombic efficiency (CE). The introduction of nanoscale carbon black provides more active sites for the storage of Zn2+, thereby improving its specific capacity. This study offers new perspectives on the design and fabrication of MOF-based cathodes for AZIBs.

Keywords: Aqueous zinc battery, Zn-based metal-organic framework, Nano-carbon black, Zinc cathode