Dual-phase nanostructuring of layered metal oxides for high-performance aqueous rechargeable potassium ion microbatteries.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31541111.
- Also identified by DOI 10.1038/s41467-019-12274-7 and PMC identifier 6754412.
- 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 rechargeable microbatteries are promising on-chip micropower sources for a wide variety of miniaturized electronics. However, their development is plagued by state-of-the-art electrode materials due to low capacity and poor rate capability. Here we show that layered potassium vanadium oxides, K<sub>x</sub>V<sub>2</sub>O<sub>5</sub>·nH<sub>2</sub>O, have an amorphous/crystalline dual-phase nanostructure to show genuine potential as high-performance anode materials of aqueous rechargeable potassium-ion microbatteries. The dual-phase nanostructured K<sub>x</sub>V<sub>2</sub>O<sub>5</sub>·nH<sub>2</sub>O keeps large interlayer spacing while removing secondary-bound interlayer water to create sufficient channels and accommodation sites for hydrated potassium cations. This unique nanostructure facilitates accessibility/transport of guest hydrated potassium cations to significantly improve practical capacity and rate performance of the constituent K<sub>x</sub>V<sub>2</sub>O<sub>5</sub>·nH<sub>2</sub>O. The potassium-ion microbatteries with K<sub>x</sub>V<sub>2</sub>O<sub>5</sub>·nH<sub>2</sub>O anode and K<sub>x</sub>MnO<sub>2</sub>·nH<sub>2</sub>O cathode constructed on interdigital-patterned nanoporous metal current microcollectors exhibit ultrahigh energy density of 103 mWh cm<sup>-3</sup> at electrical power comparable to carbon-based microsupercapacitors.