Fast Current-Driven Synthesis of ZIF-Derived Catalyst Layers for High-Performance Zn-Air Battery

As a core component, the catalyst layer (CL) is widely used in fuel cell, metal-air battery, and other energy conversion devices. Herein, a highly efficient method for CL preparation via fast current-driven synthesis followed by pyrolysis is proposed. Compared with previously reported fabrication procedures of zeolite imidazolate frameworks (ZIF)-based CLs, this method directly deposits the ZIF precursor onto the conductive substrate in a very short time (<= 15 min). The self-supporting CL, converted from ZIF membrane by simple single-step pyrolysis, is assembled with the gas diffusion layer to obtain cathode. Electrochemical tests exhibit a small potential gap (0.83 V) between the oxygen reduction and evolution reactions, as well as high performance and excellent stability for Zn-air battery (241 mW cm(-2) at 390 mA cm(-2)), due to the unique design of a bi-continuous framework (interconnected pores and long carbon nanotubes) and Co-based active sites. This work may provide new directions for the fast fabrication of non-platinum group metal CLs for metal-air batteries or fuel cell applications.

Automated summary

This study presents a highly efficient method for the preparation of catalyst layers (CLs) via fast current-driven synthesis and pyrolysis. The method allows for the direct deposition of ZIF precursors onto conductive substrates in a short time, and the conversion of ZIF membranes into self-supporting CLs through single-step pyrolysis. The resulting CLs exhibit a bi-continuous framework and Co-based active sites, leading to a small potential gap, high performance, and excellent stability.