Structural water engaged disordered vanadium oxide nanosheets for high capacity aqueous potassium-ion storage.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 28534481.
- Also identified by DOI 10.1038/ncomms15520 and PMC identifier 5457508.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
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<sup>-1</sup> in half-cells at a scan rate of 5 mV s<sup>-1</sup>, corresponding to 0.89 charge per vanadium) and excellent cyclability (62.5 mAh g<sup>-1</sup> 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.