Synthesis and Study on Ni-Co Phosphite/Activated Carbon Fabric Composited Materials with Controllable Nano-Structure for Hybrid Super-Capacitor Applications.

Dalai Jin,Saisai Li,Longcheng Wang,Jiamin Zhou,Lina Wang,Yurong Cai,Tianpeng Yang

doi:10.3390/nano11071649

Abstract

The advantage of low resistivity and inactive binders makes binder-free electrode an excellent candidate for high-performance energy devices. A simple hydrothermal method was used to fabricate M11(HPO3)8(OH)6 (M: Ni and Co) (MHP) arrays combined with activated carbon fabric (ACF) without binder. The structures of MHP can be easily tuned from bouquets to nano-sheets by the concentration of NaH2PO2. The MHP/ACF composite materials with different structures showed the typical battery-type characteristic of anodic electrodes. In a three-electrode cell configuration, the MHP nano-sheet arrays/ACF composite has a higher capacity, of 1254 F/g, at a scan rate of 10 mA/cm2 and shows better cycling stability: 84.3% remaining specific capacity after 1000 cycles of charge-discharge measurement. The composite is highly flexible, with almost the same electrochemical performance under stretching mode. The MHP/ACF composite@ACF hybrid supercapacitor can deliver the highest energy density, of 34.1 Wh·kg−1, and a power density of 722 W·kg−1 at 1 A·g−1. As indicated by the results, MHP/ACF composite materials are excellent binder-free electrodes, candidates for flexible high-performance hybrid super-capacitor devices.

Highlights

Considering that activated carbon fabric (ACF) contributes to electronic storage, it is regarded as an active material, so that m+ is the mass of the M11(HPO3)8(OH)6 (M: Ni and Co) (MHP)/ACF composite electrode, which is 0.0753 g; and m- is the mass of the ACF used as negative electrode, which is 0.0500 g
Considering that ACF contributes to electronic storage, it is regarded tuned from bouquet-like by the concentration of NaH
The nano-sheet like MHP/ACF electrode has a higher specific capacity (1254 F·g−1, 10 mA·cm−2) and better long-term stability (84.3% of capacity maintained after 1000 cycles)

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Ni/Co phosphites nano-particles on conductive substrates such as carbon fabric, graphene, and carbon nanotube were reported to have a superior electrochemical performance [17,18]. Compared with traditional metal-foil based material, ACF has the advantages of low cost, excellent electrical conductivity, and large specific surface area, which make it one of the most appreciated substrates for self-supporting electrochemical active materials. The performance of a micro/nano-structured super-capacitor highly depends on the size, shape, and distribution of particles [22,23]. It is still a great challenge for the morphology tailoring of MHP arrays on ACF substrates. The MHP/ACF composite@ACF hybrid supercapacitor exhibits an energy density of 34.1 Wh·kg− 1 and a power density of 722 W·kg− 1 at 1 A·g− 1

Materials and Methods

Characterizations

Results

Conclusions