Advanced design strategies for multi-dimensional structured carbon materials for high-performance Zn-air batteries

Zn-air batteries (ZABs) featuring high safety, low-cost, high specific capacity and environmentally friendliness have attracted much attention and emerged as a hot topic in energy storage devices. However, the sluggish kinetics of the oxygen evolution/reduction reactions (OER/ORR) at the air electrode and the non-negligible dendritic growth at the anode have hindered their large scale applications. Carbon materials with low-cost, good electrical conductivity, chemical stability and bifunctional OER/ORR activities have been widely studied for ZABs in the past few years. This review begins with a discussion of the basic working principle of ZABs, followed by an introduction of various carbon materials which focuses on their roles and superior properties in the applications of ZABs. This review also discusses the essential roles of multi-dimensional carbon materials as major components of ZABs, i.e., air electrodes, zinc anodes and separators, in improving the performance of ZABs. Finally, prospects for the future use of carbon materials to improve ZAB performance are explored.