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Cobalt vanadium chalcogenide microspheres decorated with dendrite-like fiber nanostructures for flexible wire-typed energy conversion and storage microdevices

Naderi, L ; Sharif University of Technology | 2022

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  1. Type of Document: Article
  2. DOI: 10.1039/d2nr01247b
  3. Publisher: Royal Society of Chemistry , 2022
  4. Abstract:
  5. The increasing energy demand for next-generation portable and miniaturized electronics has drawn tremendous attention to develop microscale energy storage and conversion devices with light weight and flexible characteristics. Herein, we report the preparation of flower-like cobalt vanadium selenide/nickel copper selenide (CoVSe/NiCuSe) microspheres with three-dimensional hierarchical structure of micropore growth on copper wire for a flexible fiber microsupercapacitor (microSC) and overall water splitting. The CoV-LDH microspheres are anchored on the dendrite-like NiCu nanostructured Cu wire using a hydrothermal method (CoV-LDH/NiCu@CW). The sulfidation and selenization of CoV-LDH/NiCu was carried out through the ion-exchange reaction of OH− with sulfide and selenide ions to obtain CoVS/NiCuS@CW and CoVSe/NiCuSe@CW electrodes, respectively. Benefitting from the unique structure, the flower-like CoVSe/NiCuSe@CW microspheres exhibit better electrochemical performance compared with other as-prepared fiber-shaped electrodes. As an electrode active material for microSC, CoVSe/NiCuSe microspheres exhibit a specific capacitance of 35.40 F cm−3 at 4 mA cm−2, and maintain 281.25 F cm−3 even at a high current density of 83 mA cm−2, indicating outstanding charge storage capacitance and excellent rate capability. Moreover, the assembled flexible solid-state asymmetric microSCs based on flower-like CoVSe/NiCuSe microspheres-coated Cu wire as the positive electrode and polypyrrole/reduced graphene oxide-coated carbon fiber as the negative electrode manifests a maximum energy density of 20.17 mW h cm−3 at a power density of 624.32 mW cm−3 and remarkable cycling stability (96.7% after 5000 cycles) with good mechanical stability. As an electrocatalyst for oxygen and hydrogen evolution reactions in alkaline medium, the CoVSe/NiCuSe electrode delivers an overpotential of 297 mV and 165 mV at 100 mA cm−2. Furthermore, the CoVSe/NiCuSe-based electrolysis cell for overall water splitting presents a low cell voltage (1.7 V at 50 mA cm−2) as well as high durability. © 2022 The Royal Society of Chemistry
  6. Keywords:
  7. Capacitance ; Carbon fibers ; Cobalt compounds ; Cobalt deposits ; Copper compounds ; Electrocatalysts ; Electrochemical electrodes ; Energy storage ; Flexible electronics ; Mechanical stability ; Microspheres ; Nanosheets ; Nanowires ; Polypyrroles ; Storage (materials) ; Sulfur compounds ; Supercapacitor ; Wire ; Cu wires ; Energy conversion and storages ; Energy demands ; Energy storage and conversions ; Micro-device ; Microscale energy ; Microsupercapacitors ; Miniaturized electronics ; Portable electronics ; Water splitting ; Graphene
  8. Source: Nanoscale ; Volume 14, Issue 25 , 2022 , Pages 9150-9168 ; 20403364 (ISSN)
  9. URL: https://pubs.rsc.org/en/content/articlelanding/2022/nr/d2nr01247b