FeNi Nanoparticles Coated on N‐doped Ultrathin Graphene‐like Nanosheets as Stable Bifunctional Catalyst for Zn‐Air Batteries

Abstract

High‐performance and low‐cost bifunctional catalysts are crucial to energy conversion and storage devices. Herein, a novel oxygen electrode catalyst with high oxygen evolution reaction and oxygen reduction reaction (OER/ORR) performance is reported based on bimetal FeNi nanoparticles anchored on N‐doped graphene‐like carbon (FeNi/N−C). The complete 2D ultrathin carbon nanosheet is induced by etching and stripping of molten sodium chloride and its ions in the carbonization process at suitable temperature. The obtained FeNi/N−C catalyst exhibits rapid reaction kinetics for OER, efficient four electron transfer for ORR, and outstanding bifunctional performance with reversible oxygen electrode index of 0.87 V for OER/ORR. Zn‐air batteries with a high open‐circuit voltage of 1.46 V and a stable discharge voltage of 1.23 V are assembled using liquid electrolytes, zinc sheet as Zn‐electrode and FeNi/N−C coating on carbon cloth as air‐electrode. The specific capacity is as high as 816 mAh g−1 and there is extremely little decay after charge‐discharge cycle time of 275 h for the FeNi/N−C as oxygen electrode catalyst in Zn‐air battery, which are much better than that assembled with Pt/C−RuO2 catalyst.

Synergetic Effects of Mixed-Metal Polyoxometalates@Carbon-Based Composites as Electrocatalysts for the Oxygen Reduction and the Oxygen Evolution Reactions

“…Our results with Ni 4 @MWCNT_N6 and Fe 4 @MWCNT_N6 are comparable with those reported in the literature (Table S1) for other POM-containing composites, but Fe 2 Ni 2 @MWCNT_N6 outperformed all, even the Co-containing POMs well known for their good OER activities [59][60][61][62]. Compared with other metal-oxide-containing composites, our results outperformed some [63][64][65], but others presented even lower overpotentials (0.28-0.32 V) [66][67][68].…”

“…S1. Comparison of the OER electrochemical performance (overpotentials (η 10 ) and current density (j)) for POM-based composite materials reported in literature [6,41,54,[63][64][65][66][67][68][69][70][71][72][73][74][75][76][77].…”

Metal–Organic Frameworks (MOFs) Derived Materials Used in Zn–Air Battery

“…Currently, most of the MOF-derived Fe-containing bimetallic catalysts focused on FeCo bifunctional electrocatalyst. Other Fe-containing bimetallic ORR/OER catalysts are mainly supported by carbon materials such as graphene, carbon nanotubes, and g-C 3 N 4 , such as FeMn-based bifunctional electrocatalyst [ 111 , 112 , 113 ], FeNi-based bifunctional electrocatalyst [ 114 , 115 , 116 , 117 , 118 ], and FeCu-based bifunctional electrocatalyst [ 119 ]. There are few reports on other Fe-containing bimetallic catalysts derived from MOF for ORR/OER.…”

Mechanosynthesis of a bifunctional FeNi–N–C oxygen electrocatalyst via facile mixed-phase templating and preheating-pyrolysis

“…19,20 In particular, iron-based single-atom catalysts were reported to exhibit an outstanding ORR performance, 21,22 and iron–nickel nanoparticles showed excellent OER performance. 23–27…”

“…19,20 In particular, iron-based single-atom catalysts were reported to exhibit an outstanding ORR performance, 21,22 and iron-nickel nanoparticles showed excellent OER performance. [23][24][25][26][27] Currently, most synthetic methods for M-N-C involve solvent-based approaches (dissolution, hydrothermal/solvothermal, and precipitation), which can oen generate a substantial quantity of waste and be material, cost, and energy intensive. 28,29 Therefore, in recent studies, mechanosynthesis has been employed as an effective and greener alternative for conventional solvent-based synthesis to reduce or eliminate the generation of waste and material and energy overuse.…”