Janus Hollow Nanofiber with Bifunctional Oxygen Electrocatalyst for Rechargeable Zn–Air Battery

Abstract

Zn–air battery technologies have received increasing attention, while the application is hindered by the sluggish kinetics of the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). In order to explore an efficient method to fabricate a high‐performance electrocatalyst via modification of advanced nanostructure, a coaxial electrospinning method with in‐situ synthesis and subsequent carbonization to construct 3D flexible Janus‐like electrocatalysts is developed. The resulting Janus nanofibers have a unique core–shell hollow fiber structure, where NiFe alloy electrocatalysts supported by N‐doped carbon nanobelt are located on the inner wall of the carbon layer, and leaf‐like Co–N nanosheets are anchored on the outer wall of the carbon layer. As a result, the electrocatalyst exhibits excellent bifunctional catalytic performance for ORR and OER, demonstrating the small potential gap value of 0.73 V between the ORR half‐wave potential and the OER potential at 10 mA cm−2, which is even comparable to the mixed commercial noble catalyst with 20% Pt/C and RuO2. The rechargeable Zn–air battery is constructed and displays a large open‐circuit voltage of 1.44 V, high power density (130 mW cm−2) and energy density (874 Wh kg−1). This study provides a concept to synthesize and construct high performance bifunctional electrocatalysts.

Tunable phosphorization degree of CoxPy@N,P-doped carbon as a highly-active bifunctional electrocatalyst for rechargeable zinc–air batteries

“…Meanwhile, the Co 2 P@NPPC catalyst can also provide the rechargeable zinc–air batteries with excellent rechargeability. After 160 hours of operation at 10 mA cm −2 , 52,53 the change of the charging and discharging pressure gap was observed to be negligible. It outperforms Pt/C + RuO 2 -based zinc–air (Fig.…”

Ultrahigh-Loaded Fe Single Atoms and Fe3C Nanoparticle Catalysts as Air Cathodes for High-Performance Zn–Air Batteries

“…Figure c shows that the voltage changed when different current densities were applied at the beginning, but the voltage was normal at the same current density, indicating that the material not only had good stability but also had good rate performance. From the polarization curves, it served to show that the power densities of Fe 3 C-FeSA@3DCN and Pt/C base were 166 and 144 mW cm –2 , respectively (Figure d) . The specific capacities of Fe 3 C-FeSA@3DCN at 5, 10, and 15 mA cm –2 were 844, 788, and 759 W h g –1 , respectively (Figure e) (eq S5).…”

Research progress on the construction of synergistic electrocatalytic ORR/OER self-supporting cathodes for zinc–air batteries

“…6b). 142 Xia et al prepared a polyacrylonitrile (PAN) nanofiber film by electrospinning, and then prepared a nitrogen-doped carbon nanofiber supported nanoparticle (Co/CNW/CNF) bifunctional oxygen electrode by subsequent heat treatment. N-doping and coordination of dispersed Co nanoparticles in the carbon matrix formed rich Co–N–C sites (Fig.…”