Phase-engineered cathode for super-stable potassium storage.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36746953.
- Also identified by DOI 10.1038/s41467-023-36385-4 and PMC identifier 9902589.
- 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
The crystal phase structure of cathode material plays an important role in the cell performance. During cycling, the cathode material experiences immense stress due to phase transformation, resulting in capacity degradation. Here, we show phase-engineered VO<sub>2</sub> as an improved potassium-ion battery cathode; specifically, the amorphous VO<sub>2</sub> exhibits superior K storage ability, while the crystalline M phase VO<sub>2</sub> cannot even store K<sup>+</sup> ions stably. In contrast to other crystal phases, amorphous VO<sub>2</sub> exhibits alleviated volume variation and improved electrochemical performance, leading to a maximum capacity of 111 mAh g<sup>-1</sup> delivered at 20 mA g<sup>-1</sup> and over 8 months of operation with good coulombic efficiency at 100 mA g<sup>-1</sup>. The capacity retention reaches 80% after 8500 cycles at 500 mA g<sup>-1</sup>. This work illustrates the effectiveness and superiority of phase engineering and provides meaningful insights into material optimization for rechargeable batteries.