Tailoring structural properties of carbon via implanting optimal co nanoparticles in n‐rich carbon cages toward high‐efficiency oxygen electrocatalysis for rechargeable zn‐air batteries

Abstract

Rational construction of carbon‐based materials with high‐efficiency bifunctionality and low cost as the substitute of precious metal catalyst shows a highly practical value for rechargeable Zn‐air batteries (ZABs) yet it still remains challenging. Herein, this study employs a simple mixing‐calcination strategy to fabricate a high‐performance bifunctional composite catalyst composed of N‐doped graphitic carbon encapsulating Co nanoparticles (Co@NrC). Benefiting from the core‐shell architectural and compositional advantages of favorable electronic configuration, more exposed active sites, sufficient electric conductivity, rich defects, and excellent charge transport, the optimal Co@NrC hybrid (Co@NrC‐0.3) presents outstanding catalytic activity and stability toward oxygen‐related electrochemical reactions (oxygen reduction and evolution reactions, i.e., ORR and OER), with a low potential gap of 0.766 V. Besides, the rechargeable liquid ZAB assembled with this hybrid electrocatalyst delivers a high peak power density of 168 mW cm−2, a small initial discharge‐charge potential gap of 0.45 V at 10 mA cm−2, and a good rate performance. Furthermore, a relatively large power density of 108 mW cm−2 is also obtained with the Co@NrC‐0.3‐based flexible solid‐state ZAB, which can well power LED lights. Such work offers insights in developing excellent bifunctional electrocatalysts for both OER and ORR and highlights their potential applications in metal‐air batteries and other energy‐conversion/storage devices.

Tuning d Orbital of Ni Single Atom by Encapsulating Ni Nanoparticle in Carbon Nanotube for Efficient Oxygen Evolution Reaction

“…The schematic synthesis process of Ni@NiNCNT catalyst based on simple and reliable one-step pyrolysis 23 is shown in Figure 1. Briefly, nickel nitrate is added to a well-mixed solution of melamine and ethanol and dried in the oven as a precursor.…”

Oxygenated P/N co-doped carbon for efficient 2e−oxygen reduction to H2O2

“…The selectivity of the H 2 O 2 percentage and the transfer electron number ( n ) were calculated using following eqn (2) and (3). 37 where I r is the ring current, I d is the disk current and N is the collection efficiency (0.39 after calibration).…”

N-, P-, and Ni-Co-doped Porous Carbon from Poplar Powder and Graphene Oxide Composites as Electrode Materials for Supercapacitors

“…24,25 And the doping of heteroatoms will generate more defects and functional groups on the carbon surface, thus providing more active sites and additional Faraday pseudocapacitance. 26 For example, the phosphorus dopant has good electron-donating ability, the electronegativity of the P atom is low, and the atomic size is relatively large, which can change the local charge density and improve the stability of the active oxygen group on the surfacing of materials in the discharging process. In turn, the charge storage and transmission capacity of the carbon material are effectively improved, and the effect of increasing the capacitance is achieved.…”