3 years ago

Monodisperse Metallic NiCoSe2 Hollow Sub-Microspheres: Formation Process, Intrinsic Charge-Storage Mechanism, and Appealing Pseudocapacitance as Highly Conductive Electrode for Electrochemical Supercapacitors

Monodisperse Metallic NiCoSe2 Hollow Sub-Microspheres: Formation Process, Intrinsic Charge-Storage Mechanism, and Appealing Pseudocapacitance as Highly Conductive Electrode for Electrochemical Supercapacitors
Yaoyao Shi, Yangzhou Ma, Xiaogang Zhang, Chen Wu, Changzhou Yuan, Yanru Zhang, Xuan Sun, Linrui Hou, Jinfeng Sun
Highly conductive metal selenides are gaining prominence as promising electrode materials in electrochemical energy-storage fields. However, phase-pure bimetallic selenides are scarcely retrieved, and their underlying charge-storage mechanisms are still far from clear. Here, first a solvothermal strategy is devised to purposefully fabricate monodisperse hollow NiCoSe2 (H-NiCoSe2) sub-microspheres. Inherent formation of metallic H-NiCoSe2 is tentatively put forward with comparative structure-evolution investigations. Interestingly, the fresh H-NiCoSe2 does not demonstrate striking supercapacitive behaviors when evaluated for electrochemical supercapacitors (ESs). But it exhibits competitive pseudocapacitance of ≈750 F g−1 at a rate of 3 A g−1 with a high loading of 7 mg cm−2 after ≈100 cyclic voltammetry (CV) cycles. With systematic physicochemical/electrochemical analyses, intrinsic energy-storage mechanism of the H-NiCoSe2 is convincingly revealed that the electrooxidation-generated biactive CoOOH/NiOOH phases in aqueous KOH over CV scanning, rather than the H-NiCoSe2 itself, account for the remarkable pesudocapacitance observed after cycling. An assembled H-NiCoSe2-based asymmetric device has delivered an energy density of ≈25.5 Wh kg−1 with a power rate of ≈3.75 kW kg−1, and long-span cycle life. More significantly, the electrode design and new perspectives here hold profound promise in enriching material synthesis methodologies and in-depth understanding of the complex charge-storage process of newly emerging pseudocapacitive materials for next-generation ESs. Monodisperse metallic NiCoSe2 hollow sub-microspheres are rationally fabricated and exhibit excellent electrochemical pseudocapacitances with electrooxidation-induced phase transformation charge-storage mechanisms for electrochemical supercapacitors.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/adfm.201705921

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.