Entropy and crystal-facet modulation of P2-type layered cathodes for long-lasting sodium-based batteries.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35595772.
- Also identified by DOI 10.1038/s41467-022-30113-0 and PMC identifier 9123165.
- 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
P2-type sodium manganese-rich layered oxides are promising cathode candidates for sodium-based batteries because of their appealing cost-effective and capacity features. However, the structural distortion and cationic rearrangement induced by irreversible phase transition and anionic redox reaction at high cell voltage (i.e., >4.0 V) cause sluggish Na-ion kinetics and severe capacity decay. To circumvent these issues, here, we report a strategy to develop P2-type layered cathodes via configurational entropy and ion-diffusion structural tuning. In situ synchrotron X-ray diffraction combined with electrochemical kinetic tests and microstructural characterizations reveal that the entropy-tuned Na<sub>0.62</sub>Mn<sub>0.67</sub>Ni<sub>0.23</sub>Cu<sub>0.05</sub>Mg<sub>0.07</sub>Ti<sub>0.01</sub>O<sub>2</sub> (CuMgTi-571) cathode possesses more {010} active facet, improved structural and thermal stability and faster anionic redox kinetics compared to Na<sub>0.62</sub>Mn<sub>0.67</sub>Ni<sub>0.37</sub>O<sub>2</sub>. When tested in combination with a Na metal anode and a non-aqueous NaClO<sub>4</sub>-based electrolyte solution in coin cell configuration, the CuMgTi-571-based positive electrode enables an 87% capacity retention after 500 cycles at 120 mA g<sup>-1</sup> and about 75% capacity retention after 2000 cycles at 1.2 A g<sup>-1</sup>.