An easy synthesis of Ni-Co doped hollow C-N tubular nanocomposites as excellent cathodic catalysts of alkaline and neutral zinc-air batteries

Abstract

Exploring high-activity electrocatalyst for oxygen reduction reaction (ORR) is of great significance for a variety of renewable energy conversion and storage technologies. Herein, we fabricated novel ORR electrocatalysts derived from Ni-Co nanoparticles encapsulated in hollow tubular C-N composites (ht-CN) through an easy and scalable pyrolysis route utilizing nickel acetate and cobalt acetate as metal precursors, 2-cyanoguanidine as the nitrogen source, and sucrose as the carbon source. Among the prepared nanocomposite catalysts with different molar ratios of Ni/Co, the catalyst Ni 2 Co 3 @ht-CN exhibits an outstanding ORR electroactivity comparable to Pt/C catalyst both in alkaline and neutral media. Home-made zinc-air battery with the Ni 2 Co 3 @ht-CN as cathode electrocatalyst presents excellent performance and superior durability either in neutral or alkaline medium. The Ni 2 Co 3 @ht-CN battery delivers an open circuit voltage of 1.08 V and a maximum power density of 47 mW cm −2 in 0.5 mol L −1 KNO 3 solution, while 1.51 V and 314 mW cm −2 in 6 mol L −1 KOH solution. In addition, whether in neutral or alkaline solution, the constant current discharge curves of the Ni 2 Co 3 @ht-CN battery at different current densities exhibit higher voltage plateau and stability than the Pt/C battery. Results demonstrate the potential application of the catalysts of the present investigation to Zn-air batteries both in alkaline and neutral media.

Flexible and Wearable Power Sources for Next‐Generation Wearable Electronics

“…Interested readers may refer to the previously reported studies. [123][124][125][126][127][128] As for the specific flexible and wearable metalÀ air batteries, air electrodes are required to meet the characteristics of high porosity to promote the diffusion of oxygen and large surface area to promote ORR and OER on active sites. 3D carbon fiber materials such as carbon fiber paper, carbon cloth, and carbon felt are widely used as current collectors for air electrodes in metalÀ air batteries due to their unique porous networks, high electrical conductivity, and good mechanical stability.…”

Pt/Zn heterostructure as efficient air-electrocatalyst for long-life neutral Zn-air batteries

“…These outcomes degrade the performance and shorten the service life of alkaline ZABs [8,9]. To alleviate the above problems, ZABs with neutral electrolyte are considered as the feasible alternatives to replace the alkaline ones [10][11][12]. Nevertheless, the catalytic properties of electrocatalyst for oxygen evolution reaction (OER)/oxygen reduction reaction (ORR) in the air cathode are unsatisfactory in neutral electrolyte [13].…”

Ultrasmall NiFe layered double hydroxide strongly coupled on atomically dispersed FeCo-NC nanoflowers as efficient bifunctional catalyst for rechargeable Zn-air battery

“…Carbon-based composites are a typical family of functional materials for electrochemical applications due to their low costs, high adjustibility, high conductivity and compatibility with the secondary metallic components [1][2][3][4][5]. Carbon materials such as graphene/carbon nanotube (CNT) oxide, reduced/heteroatom-doped graphene/ CNT oxide, and synthetic heteroatom-doped carbon are the most commonly used substrates for depositing metallic compounds [6][7][8][9][10][11][12]. In most cases, they act as templates or conductive substrates [13,14], while a few of them have been developed as co-catalysts [15][16][17].…”