As a typical battery-type material, CuCo2S4 is a promising candidate for supercapacitors due to the high theoretical specific capacity. However, its practical application is plagued by inherently sluggish ion diffusion kinetics and inferior electrical transport properties. Herein, sulfur vacancies are incorporated in CuCo2S4 hollow nanoarchitectures (HNs) to accelerate redox reactivity. Experimental analyses and theoretical investigations uncover that the generated sulfur vacancies increase the active electron states, reduce the adsorption barriers of electrolyte ions, and enrich reactive redox species, thus achieving enhanced electrochemical performance. Consequently, the deficient CuCo2S4 with optimized vacancy concentration presents a high specific capacity of 231 mAh g−1 at 1 A g−1, a ≈1.78 times increase compared to that of pristine CuCo2S4, and exhibits a superior rate capability (73.8% capacity retention at 20 A g−1). Furthermore, flexible solid-state asymmetric supercapacitor devices assembled with the deficient CuCo2S4 HNs and VN nanosheets deliver a high energy density of 61.4 W h kg−1 at 750 W kg−1. Under different bending states, the devices display exceptional mechanical flexibility with no obvious change in CV curves at 50 mV s−1. These findings provide insights for regulating electrode reactivity of battery-type materials through intentional nanoarchitectonics and vacancy engineering.
|Publication status||Published - 2022 Feb 3|
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the NanoMaterial Technology Development Program (NRF 2017M3A7B4041987) and the Korea government (MIST) (NRF-2019R1A2C2090443). S.L. and Y.Y. to gratefully acknowledge the financial support from the Australian National Fabrication Facility's Queensland Node (ANFF-Q), and the JST-ERATO Yamauchi Materials Space-Tectonics Project (JPMJER2003).
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the NanoMaterial Technology Development Program (NRF 2017M3A7B4041987) and the Korea government (MIST) (NRF‐2019R1A2C2090443). S.L. and Y.Y. to gratefully acknowledge the financial support from the Australian National Fabrication Facility's Queensland Node (ANFF‐Q), and the JST‐ERATO Yamauchi Materials Space‐Tectonics Project (JPMJER2003).
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All Science Journal Classification (ASJC) codes
- Materials Science(all)