Superior stability of a bifunctional oxygen electrode for primary, rechargeable and flexible Zn–air batteries

Abstract

Central to commercializing metal-air batteries is the development of highly efficient and stable catalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). In this study, a composite catalyst with a unique interpenetrating network (denoted as NiCo2O4@MnO2-CNTs-3) was synthesized and exhibited better bifunctional activity (ΔE = 0.87 V) and durability than both Pt/C and Ir/C catalysts. The improved performance arises from three factors: (i) MnO2 promotes the ORR while NiCo2O4 facilitates the OER; (ii) carbon nanotubes improve the electronic conductivity; and (iii) the highly porous structure enables the adsorption-desorption of O2 and enhances the structural stability. As a result, the primary and rechargeable Zn-air battery affords a high power density and specific capacity (722 mA h g-1), an outstanding discharge stability (255 mW cm-2 after 1000 cycles) and a high cycling stability (over 2280 cycles). Electron microscopy and electrochemical analysis revealed that the degradation of the rechargeable Zn-air battery performance resulted from the damage of the air electrode and the hydrogen evolution reaction on the zinc electrode. A flexible Zn-air battery employing a solid-state electrolyte showed an exciting stability (540 cycles) and high power density (85.9 mW cm-2), suggesting that the anion exchange membrane effectively prevents the migration of Zn2+ ions and the deposition of carbonates.

Mesoporous ZnMn2O4 Nanospheres as a Nonprecious Bifunctional Catalyst for Zn–Air Batteries

“…Despite these advantages, the moderate kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) have impeded the commercialization of Zn−air batteries. 3 To alleviate these problems, research in the field of Zn−air batteries has focused on the development of efficient cathode catalysts based on various materials including noble metals and alloys, carbon-based materials, transition metal oxides, and nonmetal oxide materials. 4−9 As efficient cathode catalysts for Zn−air batteries in aqueous alkaline solution, transition metal oxides are of particular interest owing to their high abundance, ease of synthesis, nonflammability, and environmental friendliness.…”

Synthesis of Ti4O7/Ti3O5 Dual-Phase Nanofibers with Coherent Interface for Oxygen Reduction Reaction Electrocatalysts

“…The development of new clean energy technologies is imperative in recent years due to the serious energy crisis and environmental pollution [ 1 , 2 , 3 ]. As the two most promising new energy technologies, fuel cells and metal-air batteries possess excellent safety and sustainability, which has attracted more attention in recent years [ 4 , 5 ]. These two devices enjoy the same cathodic oxygen reduction reaction: , which is the key reaction to improve the performance and energy conversion efficiency [ 6 , 7 , 8 ].…”

Mapping the Design of Electrolyte Materials for Electrically Rechargeable Zinc–Air Batteries

“…For instance, Zirfon PERL UTP 500, Tokuyama A901, and Tokuyama A201 membranes have been applied in ERZAB assemblies. [59][60][61][62] In addition, electrolyte reservoir membranes (e.g., filter paper and cellulose membranes) prewetted in an alkaline electrolyte solution have also served as the electrolytes in ERZABs. [63][64][65] GPEs, which are composed of polymer matrices and electrolyte solutions, combine the advantages of solid and liquid electrolytes resulting in good mechanical strength and relatively high ionic conductivities under ambient conditions (10 −4 -10 −1 S cm −1 ).…”