Zinc–Air Battery: Understanding the Structure and Morphology Changes of Graphene-Supported CoMn₂O₄Bifunctional Catalysts Under Practical Rechargeable Conditions

Abstract

Nitrogen-doped/undoped thermally reduced graphene oxide (N-rGO) decorated with CoMn2O4 (CMO) nanoparticles were synthesized using a simple one-step hydrothermal method. The activity and stability of this hybrid catalyst were evaluated by preparing air electrodes with both primary and rechargeable zinc-air batteries that consume ambient air. Further, we investigated the relationship between the physical properties and the electrochemical results for hybrid electrodes at various cycles using X-ray diffraction, scanning electron microscopy, galvanodynamic charge-discharging and electrochemical impedance spectroscopy. The structural, morphological and electrocatalytic performances confirm that CMO/N-rGO is a promising material for safe, reliable, and long-lasting air cathodes for both primary and rechargeable zinc-air batteries that consume air under ambient condition.

PVP assisted morphology-controlled synthesis of hierarchical mesoporous ZnCo 2 O 4 nanoparticles for high-performance pseudocapacitor

“…NiO [8], MnO 2 [9], Co 3 O 4 [10], polyaniline [11] and polypyrrole [12] are some of the metal oxides and conducting polymers that are being investigated as promising electrode materials for PCs. Additionally, ternary oxides that provide richer redox chemistry such as ZnCo 2 O 4 [13], NiCo 2 O 4 [14], MnCo 2 O 4 [15] and CoMnO 4 [16], have been focused on the recent studies regarding the improvement of PCs. Among the mentioned ternary oxides, ZnCo 2 O 4 has attracted much interest and attention because of its better electrochemical activity and it exhibit higher conductivity.…”

Highly active Co-doped LaMnO 3 perovskite oxide and N-doped carbon nanotube hybrid bi-functional catalyst for rechargeable zinc–air batteries

“…[8,9] Thus, affordable yet highly efficient catalyst bi-functionally active towards both ORR and OER with enhanced durability must be developed for rechargeable zinc-air batteries. [10][11][12] Recently, different classes of materials such as non-precious transition metal based oxides [13], metal-free nanostructured carbons [14], and hybrids that combine the two [15] have been reported as bi-functionally active catalysts which could potentially replace precious metal based catalysts.…”

Sequentially Electrodeposited MnOX/Co-Fe as Bifunctional Electrocatalysts for Rechargeable Zinc-Air Batteries

“…1,2 However, due to the sluggish oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) at the air electrode, the efficiency of zincair batteries is comparatively low, leading to energy losses. 3 Also, catalyst stability is a problem, because the catalyst can detach from the current collector or pulverize during battery cycling. 4 Currently, some precious metals such as Pt, Ru and Ir are recognized as the most active ORR or OER electrocatalysts.…”