Structural water engaged disordered vanadium oxide nanosheets for high capacity aqueous potassium-ion storage.

Academic Article

Abstract

  • Aqueous electrochemical energy storage devices using potassium-ions as charge carriers are attractive due to their superior safety, lower cost and excellent transport properties compared to other alkali ions. However, the accommodation of potassium-ions with satisfactory capacity and cyclability is difficult because the large ionic radius of potassium-ions causes structural distortion and instabilities even in layered electrodes. Here we report that water induces structural rearrangements of the vanadium-oxygen octahedra and enhances stability of the highly disordered potassium-intercalated vanadium oxide nanosheets. The vanadium oxide nanosheets engaged by structural water achieves high capacity (183 mAh g-1 in half-cells at a scan rate of 5 mV s-1, corresponding to 0.89 charge per vanadium) and excellent cyclability (62.5 mAh g-1 in full cells after 5,000 cycles at 10 C). The promotional effects of structural water on the disordered vanadium oxide nanosheets will contribute to the exploration of disordered structures from earth-abundant elements for electrochemical energy storage.
  • Authors

  • Charles, Daniel Scott
  • Feygenson, Mikhail
  • Page, Katharine
  • Neuefeind, Joerg
  • Xu, Wenqian
  • Teng, Xiaowei
  • Publication Date

  • May 23, 2017
  • Published In

    Digital Object Identifier (doi)

    Start Page

  • 15520
  • Volume

  • 8
  • Issue

  • 1