Synergy of cations in high entropy oxide lithium ion battery anode.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36932071.
- Also identified by DOI 10.1038/s41467-023-37034-6 and PMC identifier 10023782.
- 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
High entropy oxides (HEOs) with chemically disordered multi-cation structure attract intensive interest as negative electrode materials for battery applications. The outstanding electrochemical performance has been attributed to the high-entropy stabilization and the so-called 'cocktail effect'. However, the configurational entropy of the HEO, which is thermodynamically only metastable at room-temperature, is insufficient to drive the structural reversibility during conversion-type battery reaction, and the 'cocktail effect' has not been explained thus far. This work unveils the multi-cations synergy of the HEO Mg<sub>0.2</sub>Co<sub>0.2</sub>Ni<sub>0.2</sub>Cu<sub>0.2</sub>Zn<sub>0.2</sub>O at atomic and nanoscale during electrochemical reaction and explains the 'cocktail effect'. The more electronegative elements form an electrochemically inert 3-dimensional metallic nano-network enabling electron transport. The electrochemical inactive cation stabilizes an oxide nanophase, which is semi-coherent with the metallic phase and accommodates Li<sup>+</sup> ions. This self-assembled nanostructure enables stable cycling of micron-sized particles, which bypasses the need for nanoscale pre-modification required for conventional metal oxides in battery applications. This demonstrates elemental diversity is the key for optimizing multi-cation electrode materials.