A Mass Transfer-Enhanced Bifunctional Catalyst to Boost Zinc-Air Batteries

Abstract

The development of efficient and low-cost bifunctional oxygen catalysts is essential yet a challenge for zinc-air batteries (ZABs). Here, we prepared a pyrolysis-free 3-dimensional hybrid catalyst (COP-Fe@3D-LDH) with bifunctional oxygen-catalytic activity by integrating layered double hydroxides (3D-LDH) and a fully conjugated iron phthalocyanine-based covalent organic polymer (COP-Fe). More hierarchically porous and larger specific surface area (170.4 m 2 g −1 ) can effectively enhance the mass transfer process and active site exposure of cathode, allowing COP-Fe@3D-LDH to exhibit an outstanding peak power density (148.5 mW cm −2 ) and an ultralong lifespan (over 400 h at 10 mA cm −2 ) in ZABs. Accordingly, this work provides a new perspective to enhance the performance of pyrolysis-free catalysts in ZABs.