Recent Progress of Non-Noble Metal Catalysts for Oxygen Electrode in Zn-Air Batteries: A Mini Review

Abstract

Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) play crucial roles in energy conversion and storage devices. Particularly, the bifunctional ORR/OER catalysts are core components in rechargeable metal–air batteries, which have shown great promise in achieving "carbon emissions peak and carbon neutrality" goals. However, the sluggish ORR and OER kinetics at the oxygen cathode significantly hinder the performance of metal–air batteries. Although noble metal-based catalysts have been widely employed in accelerating the kinetics and improving the bifunctionality, their scarcity and high cost have limited their deployment in the market. In this review, we will discuss the ORR and OER mechanisms, propose the principles for bifunctional electrocatalysts design, and present the recent progress of the state-of-the-art bifunctional catalysts, with the focus on non-noble metal-based materials to replace the noble metal catalysts in Zn–air batteries. The perspectives for the future R&D of bifunctional electrocatalysts will be provided toward high-performance Zn–air batteries at the end of this paper.

High Performance Air Breathing Zinc-Air Battery with Pt−Ni and Pt−Co Bifunctional Electrocatalyst on N Activated Mesoporous Carbon

“…The mass activities for Pt-Co/N-MC, Pt-Ni/N-MC and Pt-Ru/C is found to be 0.29, 0.53 and 0.11 mA g −1 and their corresponding i k values are 0.92, 2.01 and 0.31 mA cm −2 respectively [80][81][82][83] and shown in the 6b as the increase of the discharge current rate there is a downward shift in the discharge potential plateau is due to the low ORR reaction kinetics. 86,87 However the step-down, from low to high current shows the voltage plateau remains the same for the step-up, from high to low current also, this shows that catalyst have the enhanced mass transfer efficiency and superior electrocatalytic activity 88 6d. The Pt-Co/N-MC catalyst initially, the discharge potential at 1.32 V and charge potential at 1.96 V having the potential difference of 0.64 V, gradually stabilized and shows the voltage drop after 36 h (110 cycles, 20 min for charging and discharging in each cycle) with the 0.85 V potential gap, voltaic efficiency was calculated 57% for 100th cycle, while for Pt-Ni/N-MC shows initially, the discharge potential at 1.32 V and charge potential at 1.85 V having the potential difference of 0.53 V, the voltage drop after 30 h (90 cycles, 20 min for charging and discharging in each cycle) with the 0.76 V potential gap, the voltaic efficiency was calculated to 58% for 90th cycle.…”

Zn, Fe Dual-Atom Sites Catalyst Constructed by Metal Vacancy Strategy for Oxygen Reduction Reaction and Zn-Air Battery

“…Since ZABs are kinetically constrained by both ORR and OER reactions, the OER performance of Zn, Fe/NC-800 was also evaluated before assembling the ZAB. The results show that the E j =10 of Zn, Fe/NC-800 in 0.1 M KOH solution is 1.573 V (Figure S15), which is comparable with reported catalysts. , Zn, Fe/NC-800 exhibits a peak PD of 170 mW cm –2 (Figure a), which is much higher than that of Pt/C (130 mW cm –2 ) and Zn/NC (117 mW cm –2 ). In addition, the open-circuit voltage of each catalyst is provided for reference (Figure S16).…”

Supporting critical raw material circularity – upcycling graphite from waste LIBs to Zn–air batteries

“…4,[10][11][12][13][14] The escalating energy consumption and the climate crisis have amplified focus on alternative green energy technologies, such as fuel cells and metal-air batteries. [15][16][17] However, these systems require active electrocatalysts to enhance the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) taking place in these devices. Currently, expensive Pt or Pt alloys on carbon carriers and RuO 2 or IrO 2 are considered the best commercial catalysts for the ORR and the OER, respectively.…”

“…Some of the most promising candidates for substituting expensive noble metal-based catalysts are carbonbased materials that are co-doped with nitrogen and transition metal(s), like Fe and Co. [23][24][25][26] Furthermore, carbon-based materials are excellent catalyst supports, due to their low cost, good electrical conductivity, durable structure, resistance to acids and bases, and good adjustability. 16,20,[26][27][28] However, the synthesis of a multifunctional catalyst material, which catalyses both reactions simultaneously, can be a great challenge due to the need for different catalytic sites and mechanisms. Pioneering work on M-N-C-type catalysts was conducted by Jasinski, who demonstrated that introducing transition metals with nitrogen into the carbon lattice through pyrolysis significantly enhances the activity of ORR electrocatalysts.…”