Significantly Enhanced Ultrathin NiCo-based MOF Nanosheet Electrodes Hybrided with Ti3C2Tx MXene for High Performance Asymmetric Supercapacitor

Yanzhong Wang 1, 2, Email

Yuexin Liu 1

Chao Wang 1, 2, Email

Hu Liu 3,4

Jiaoxia Zhang 3,7

Jing Lin 3

Jincheng Fan 5

Tao Ding 6

Jong E. Ryu 8

Zhanhu Guo 3, Email

1 School of Materials Science and Engineering, North University of China, Taiyuan 030051 China

2 Advanced energy materials and system institute, North University of China, Taiyuan 030051 China

3 Integrated Composites Laboratory (ICL), Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, TN 37966 USA

4 Key Laboratory of Materials Processing and Mold (Zhengzhou University), Ministry of Education, National Engineering Research Center for Advanced Polymer Processing Technology, Zhengzhou University, Zhengzhou, China

5 College of Materials Science and Engineering, Changsha University of Science and Technology, Changsha 410114, China

6 College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, China

7 School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China

8 Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695USA

Abstract

In situ synthesis of NiCo based metal-organic framework (MOF) nanosheets and the exfoliation of Ti3C2Tx into isolated nanosheets (MXene), called, NiCo-MOF/Ti3C2Tx hybrid nanosheets, are simultaneously achieved by a facile ultrasonic method. This method can effectively avoid the oxidation and restacking of Ti3C2Tx nanosheets, and also make them uniformly disperse on the surface of NiCo-MOF. The formed NiCo-MOF/Ti3C2Tx hybrid nanosheets achieve a high specific capacitance of 815.2 A g-1 at 1 A g-1. The practical asymmetric supercapacitor (ASC) is fabricated using activated carbon and NiCo-MOF/Ti3C2Tx hybrid nanosheets. The ASC device achieves an energy density of 39.5 Wh kg-1 at a power density of 562.5 W kg-1, and also demonstrates a suitable cycling stability with 82.3 % of capacitance retention after 10000 continuous cycles at 5 A g-1. The enhanced electrochemical property of NiCo-MOF/Ti3C2Tx is attributed to the nanosheet-like and mesoporous structure, high electronic conductivity, and synergistic effect of hybrid electroactive components.

Significantly Enhanced Ultrathin NiCo-based MOF Nanosheet Electrodes Hybrided with Ti3C2Tx MXene for High Performance Asymmetric Supercapacitor