High Performance Bifunctional Electrocatalysts Designed Based on Transition‐Metal Sulfides for Rechargeable Zn–Air Batteries

Abstract

Due to the energy crisis by the excessive consumption of fossil fuels, Zinc–air batteries (ZABs) with high theoretical energy density have attracted people‘s attention. The overall performance of ZABs is largely determined by the air cathode catalyst. Therefore, it is necessary to develop high‐efficiency and low‐cost bifunctional catalysts to replace noble metal catalysts to promote the development of ZABs. Among a variety of cathode catalysts, TMS has become a research hotspot in recent years because of its better electrical conductivity than metal phosphides and metal oxides. In this work, we focus on the means of improving the electrocatalytic performance of transition‐metal sulfides (TMS) providing ideas for us to rationally design high‐performance catalysts. Furthermore, the performance improvement law between catalyst performance and ZABs is also discussed in this work. Finally, some challenges and opportunities faced in the research of TMS electrocatalysis are briefly proposed, and strategies for improving the performance of ZABs are prospected.

Metal–air batteries for powering robots

“…Metal sulfides, due to their flexible crystal structure and controllable electronic properties, can provide abundant active sites for the OER in MABs. 101 Wang et al 102 developed an amorphous ternary metal sulfide (FeCoNiS x ) catalyst. The unique defect structure formed by surface reconstruction of this catalyst provided rich active sites for the reaction.…”

Interface engineering of bifunctional oxygen electrocatalysts for rechargeable Zn–air batteries

“…, metal single-atom materials) have been developed to improve the electrochemical performance of the ORR and OER. 5,13–17 However, the design and development of a highly efficient bifunctional electrocatalyst for both the OER and ORR are always the main challenge originating from the different reaction requirements.…”

“…5,12 To date, a series of bifunctional electrocatalysts including transition metal-based nanomaterials (e.g., alloys, oxides/sulfides/phosphides/nitrides, and metal hybrid materials) and carbon-based catalysts (e.g., metal singleatom materials) have been developed to improve the electrochemical performance of the ORR and OER. 5,[13][14][15][16][17] However, the design and development of a highly efficient bifunctional electrocatalyst for both the OER and ORR are always the main challenge originating from the different reaction requirements.…”

Interface of Nickel Sulfides Optimizing Surface Reconstruction toward Efficient Bifunctional Oxygen Electrocatalysis in Rechargeable Zinc-Air Batteries

“…Transition metal sulfides (TMSs) especially with the first triad (Fe, Co, and Ni) have been proven to be one kind of promising low-cost oxygen catalytic materials. On one hand, the narrow band gap between the 3d orbital of metal atoms and the 2p orbital of S atoms makes them beneficial for electron transport, showing better conductivity than oxides and other compounds . On the other hand, both oxygen and sulfur belong to Group 16 (chalcogen), which makes TMSs more prone to adsorption on oxygen-containing intermediates from ORR processes, leading to relatively active electrochemical catalytic behavior .…”

“…On one hand, the narrow band gap between the 3d orbital of metal atoms and the 2p orbital of S atoms makes them beneficial for electron transport, showing better conductivity than oxides and other compounds. 7 On the other hand, both oxygen and sulfur belong to Group 16 (chalcogen), which makes TMSs more prone to adsorption on oxygen-containing intermediates from ORR processes, leading to relatively active electrochemical catalytic behavior. 8 Besides, such materials have rich crystal phases with various stoichiometric ratios between metal and sulfur, which makes it possible to further improve their performance by generating sulfur vacancies, introducing heteroatoms (metal or nonmetal), or forming interfaces among polymorphs.…”