In Situ Growth of NiFe Alloy Nanoparticles Embedded into N-Doped Bamboo-like Carbon Nanotubes as a Bifunctional Electrocatalyst for Zn–Air Batteries

Abstract

Developing low-cost catalysts for electrochemical oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) with superior performance in an alkaline solution is of significance for large-scale applications in aqueous zinc-air batteries (ZABs). Herein, we describe the in situ design of embedded NiFe nanoparticles into the N-doped bamboo-like carbon nanotube (NBCNT) with high catalytic performance and stability. The obtained NiFe@NBCNT hybrid exhibits a high electrochemical activity and stability with an unexpectedly low overpotential of ∼195 mV for OER at 10 mA cm and an onset potential at 1.03 V for ORR, superior to the state-of-the-art Pt/C and RuO catalysts. Additionally, compared to the mixture of Pt/C and RuO cathodes, the ZAB based on the NiFe@NBCNT cathode displays a lower overpotential (0.80 V), higher stable round-trip efficiency (58.3%), and improved power density for 200 cycles at 10 mA cm. Apparently, the obtained results indicate that the NiFe@NBCNT hybrid is proven to be one of the best nonnoble metal catalysts for achieving commercial implementation of rechargeable ZABs.

Optimization of Catalytic Sites in Cobalt‐Modified Nitrogen‐Doped Carbon towards High‐Performance Oxygen Reduction Electrocatalysts for Zinc‐Air Batteries

“…Furthermore, a rechargeable Zn‐air battery was assembled and we carried out the cycling tests by 100 cycles at 10 mA cm −2 with the period time of 33.3 h (Figure c). The voltaic efficiency ŋ is used to estimate the performance of the Zn‐air battery through the discharge end voltage divided by the charge end voltage . The voltaic efficiency of N−C/Co‐1catalyst was 43.03 % at the 1 st cycle and retained at 41.56 % after 100 cycles, slightly better than that of Pt/C (initial 43.17 %, 100 th cycle 40.53 %).…”

“…Zinc‐air (Zn‐air) batteries, in particular, have merits of safety, low cost as well as high theoretical energy density of 1086 Wh kg −1 , which have triggered intense and ongoing research interest . Zn‐air batteries are beginning to show promising potential and commercial value . While notable advantages of Zn‐air batteries are desirable, issues of sluggish kinetics of oxygen reduction reaction (ORR) remain.…”

“…While notable advantages of Zn‐air batteries are desirable, issues of sluggish kinetics of oxygen reduction reaction (ORR) remain. To date, Pt‐based particles exhibit great catalytic activity, but their high cost and insufficient long‐time stability make them prohibitively unattractive . Hence, search for active, earth‐abundant and durable electrocatalysts for Zn‐air batteries is essential.…”

“…[2][3][4][5] Zn-air batteries are beginning to show promising potential and commercial value. [6][7][8][9] While notable advantages of Zn-air batteries are desirable, issues of sluggish kinetics of oxygen reduction reaction (ORR) remain. To date, Pt-based particles exhibit great catalytic activity, but their high cost and insufficient long-time stability make them prohibitively unattractive.…”

“…To date, Pt-based particles exhibit great catalytic activity, but their high cost and insufficient long-time stability make them prohibitively unattractive. [9][10][11][12] Hence, search for active, earthabundant and durable electrocatalysts for Zn-air batteries is essential.…”