Structurally synergetic stabilization of polyvinylpyrrolidone and co-doping boosts robust interconnected Ni(OH)2 nanosheets for high-performance asymmetric supercapacitor

Dehua Cao, Yi Li, Kunyu Chen, Zhen Li, Xinyuan Cao, Qilin Han, Zanhe Yang, Kunyapat Thummavichai, Nannan Wang*, Yanqiu Zhu

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

The occurrence of microcracks hinders the capacity performance and lifetime of electrode materials in energy storage systems. Herein, we report PVP-modified and Co doped Ni(OH)2 nanosheets with structurally robust interconnection fabricated on Ni foam by a facile hydrothermal process. Co-doping obviously makes the Ni(OH)2 nanosheets have fewer microcracks while no observable microcracks appear under PVP modification. The obtained P-CoNi-0.5 LDHs (layered double hydroxides) electrode presents the optimal specific capacitance of 2350 F g−1 (293.8 mA h g−1) at 1 A g−1 current density, which is about 3.12 times greater than that of CoNi-0 LDHs (pure Ni(OH)2). The excellent rate capability is obtained since the retained specific capacitance of 1706 F g−1 (213.3 mA h g−1) is achieved at 16 A g−1 current density. An asymmetric supercapacitor device is fabricated by using P-CoNi-0.5 LDHs and activated cow dung carbon (ACDC), as the positive and negative electrode materials respectively. It exhibits desirable energy and power densities up to 32.1 W h kg−1 at 800 W kg−1, and offers a fascinating electrochemical cyclic performance of 89.6 % capacitance retention after 4000 cycles. We suggest that the synergy of Co-doping and PVP modification makes it a promising electrode material for supercapacitor applications, and also provides a feasible strategy for the design and preparation of functional electrode materials.

Original languageEnglish
Article number106815
Number of pages10
JournalJournal of Energy Storage
Volume61
Early online date7 Feb 2023
DOIs
Publication statusPublished - 1 May 2023

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