Trimetallic Sulfide Mesoporous Nanospheres as Superior Electrocatalysts for Rechargeable Zn–Air Batteries

Abstract

Highly active and durable electrocatalysts are of great significance to accelerate the sluggish oxygen evolution and oxygen reduction reaction (OER and ORR) which are indispensable processes in practical devices such as metal–air batteries. Herein, the authors integrate morphological design with compositional manipulation, and successfully achieve well‐defined CoNiFe sulfide mesoporous nanospheres (CoNiFe‐S MNs). The as‐prepared CoNiFe‐S MNs exhibit superior OER and ORR catalytic activity, delivering a low overpotential of only 199 mV at a current density of 10 mA cm−2 in 1 m KOH solution and a half‐wave potential of 0.78 V in 0.1 m KOH solution toward OER and ORR, respectively. The CoNiFe‐S MNs involved Zn–air battery exhibits remarkable charge–discharge performance (voltage gap of 0.76 V at 2 mA cm−2) and high power density (over 140 mW cm−3). Extended‐time durability tests validate the structural recoverability of the mesoporous morphology, and the remarkable performance can be attributed to the intrinsic synergistic effect of heterometallic ions. It is believed that the method could pave the way for the design of novel electrocatalysts for Zn–air batteries.

Construction of CoP/NiCoP Nanotadpoles Heterojunction Interface for Wide pH Hydrogen Evolution Electrocatalysis and Supercapacitor

“…In P 2p spectra (Figure 2d), the binding energy of ≈129 and ≈130 eV could be assigned to the PM (M = Co or Ni) bond in P 2p 3/2 and P 2p 1/2 , and the broad peak at ≈132 eV is attributed to the PO due to the air exposure. [22][23][24] A shift in binding energy is also observed here: the binding energy for PM displays a negative shift of 0.2 and 0.13 eV with respect to that of CoP and NiCoP, respectively, implying an increased electronic density for P. [25] The shifts in binding energy reveal the different chemical states of Co and P in CoP/NiCoP NTs, suggesting the more pronounced electron transfer in CoP/NiCoP due to the interaction between CoP and NiCoP in the closely contacted heterointerface. Besides, both Ni and Co carry a partial positive charge (δ + ), while P carries a partial negative charge (δ − ), implying the formation of hydrogenases-like electronic structure, [26] and M (δ + ) and P(δ − ) act as the hydride-acceptor and proton-acceptor center, benefitting the HER process.…”

Multidimensional Ordered Bifunctional Air Electrode Enables Flash Reactants Shuttling for High‐Energy Flexible Zn‐Air Batteries

“…Flexible electrochemical energy conversion and storage systems are under blooming development in the last decade . Particularly, Zn‐air batteries (ZABs) with superiorities of high theoretical energy density (1218 Wh kg −1 ), low cost, and high safety possess remarkable potential to meet the increasing practical requirements of flexible and wearable electronics . Nevertheless, unsatisfactory rechargeability and energy efficiency as a result of the sluggish oxygen reaction kinetics in the air electrode still significantly hinder the applications of flexible ZABs (FZABs).…”

Metal–organic framework based bifunctional oxygen electrocatalysts for rechargeable zinc–air batteries: current progress and prospects

“…9H). 120 The synergistic effect of trimetallic ions and the high porous structure of the catalyst enables the high OER and ORR performance of CoNiFe-S. The CoNiFe-S involved ZAB exhibits a voltage gap of 0.76 V and a high power density of 140 mW cm À3 (Fig.…”

“…121,122 For example, XPS spectra of CoNiFe-S aer both chronoamperometric and cyclic voltammetry tests indicated the disappearance of metal-S peaks and the positive shi of Co, Ni, and Fe 2p peaks, demonstrating the oxidation of the suldes to oxides or (oxy)hydroxides. 120 Therefore, it is important to carry out in situ analysis to reveal the transfer process and reveal real active sites.…”