Ultrastable FeCo Bifunctional Electrocatalyst on Se-Doped CNTs for Liquid and Flexible All-Solid-State Rechargeable Zn–Air Batteries

Abstract

The rechargeable Zn−air batteries as an environmentally friendly sustainable energy technology have been extensively studied. However, it is still a challenge to develop non-noble metal bifunctional catalysts with high oxygen reduction as well as oxygen evolution reaction (ORR and OER) activity and superior durability, which limit the large-scale application of rechargeable Zn−air batteries. Herein, we synthesized an ultrastable FeCo bifunctional oxygen electrocatalyst on Se-doped CNTs (FeCo/Se-CNT) via a gravity guided chemical vapor deposition (CVD) strategy. The catalyst exhibits excellent ORR (E 1/2 = 0.9 V) and OER (overpotential at 10 mA cm −2 = 340 mV) properties simultaneously, surpassing commercial Pt/C and RuO 2 /C catalysts. More importantly, the catalyst shows an unordinary stability, that is, is no obvious decrease after 30K cycles accelerated durability test for ORR and OER processes. The small potential gap (0.75 V) represents superior bifunctional ORR and OER activities of the FeCo/ Se-CNT catalyst. The FeCo/Se-CNT catalyst possesses outstanding electrochemical performance for the rechargeable liquid and flexible all-solid-state Zn−air batteries, for example, a high open circuit voltage (OCV) and peak power density of 1.543 and 1.405 V and 173.4 and 37.5 mW cm −2 , respectively.

Recent progress and future perspectives of flexible metal‐air batteries

“…(C) SEM and HR‐TEM images of the FeCo/Se‐CNT catalyst. Reproduced with permission: Copyright 2021, American Chemical Society 147 (D) Different coordinated configurations of atomic dispersion catalysts. Reproduced with permission: Copyright 2021, Wiley‐VCH 140 (E) FESEM and HAADF‐STEM of Co SA@NCF/CNF.…”

Highly Efficient Oxidative Cyanation of Aldehydes to Nitriles over Se,S,N‐tri‐Doped Hierarchically Porous Carbon Nanosheets

“…The presence of C, N, Se and S could be further confirmed from XPS survey spectrum (Figure S5). The Se 3d spectrum was split into two well‐defined peaks at 55.94 and 58.82 eV (Figure 2 B), which corresponded to the Se‐S and C‐Se units [17] . From the high‐resolution N 1 s spectrum (Figure 2 C), there were three types of N species, including pyridine‐type N (398.15 eV), pyrrole‐type N (399.4 eV), and graphitic‐type N (400.59 eV).…”

“…TheS e3 ds pectrum was split into two well-defined peaks at 55.94 and 58.82 eV (Figure 2B), which corresponded to the Se-S and C-Se units. [17] From the high-resolution N1sspectrum (Figure 2C), there were three types of Nspecies,including pyridine-type N Angewandte Chemie (398.15 eV), pyrrole-type N(399.4 eV), and graphitic-type N (400.59 eV). Furthermore,S2 ps pectrum revealed the presence of S 2+ (164.05 and 161.08 eV,a ssigned to S-Se and S-C units) and S 6+ (167.75 eV,a ssigned to sulfone units) species (Figure 2D).…”

Highly Efficient Oxidative Cyanation of Aldehydes to Nitriles over Se,S,N‐tri‐Doped Hierarchically Porous Carbon Nanosheets

“…TheS e3 ds pectrum was split into two well-defined peaks at 55.94 and 58.82 eV (Figure 2B), which corresponded to the Se-S and C-Se units. [17] From the high-resolution N1sspectrum (Figure 2C), there were three types of Nspecies,including pyridine-type N…”