Wei, Runzhe;
Lu, Yi;
Ren, Wanjun;
Han, Yupei;
Saroja, Ajay Piriya Vijaya Kumar;
Xia, Xueming;
He, Pan;
... Xu, Yang; + view all
(2024)
Enhancing reversible Na-ion intercalation by introducing K-ions into layered vanadyl phosphate for sodium-ion battery cathodes.
Journal of Physics: Energy
, 6
(2)
, Article 025022. 10.1088/2515-7655/ad3c27.
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Abstract
Vanadium-based phosphates are being extensively studied as an important family of sodium-ion battery (SIB) cathodes. Among many compositions, NaVOPO4 is considered because of various polymorphs and the high redox potential of V4+/5+. However, due to relatively poor intrinsic kinetics and electronic conductivity, approaches such as nanostructuring and carbon composites are commonly used to avoid fast performance degradation. Being different from mainstream approaches, this work utilizes the knowledge gained from potassium-ion batteries (PIBs) and applies layered KVOPO4, a PIB cathode material, as a SIB cathode material. The results demonstrate that KVOPO4 experiences an electrochemical K+-Na+ exchange during the initial cycle and a Na-dominated (de)intercalation process in the following cycles. The initial exchange results in a small amount of K+ (∼0.1 K per formula) remaining in the interlayer space and owing to the larger size of K+ than Na+, the residual K+ effectively acts as ‘pillars’ to expand interlayer spacing and facilitates the Na (de)intercalation, leading to enhanced reversible Na storage and diffusion kinetics of KVOPO4 compared to its Na counterpart NaVOPO4. KVOPO4 delivers an initial discharge capacity of 120 mAh g−1 (90% of the theoretical capacity) at 10 mA g−1 and retains 88% capacity after 150 cycles. It also delivers 52 mAh g−1 at 1 A g−1 and 91% capacity retention after 1000 cycles at 100 mA g−1, completely outperforming NaVOPO4
| Type: | Article |
|---|---|
| Title: | Enhancing reversible Na-ion intercalation by introducing K-ions into layered vanadyl phosphate for sodium-ion battery cathodes |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1088/2515-7655/ad3c27 |
| Publisher version: | http://dx.doi.org/10.1088/2515-7655/ad3c27 |
| Language: | English |
| Additional information: | This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third-party material in this article are included in the Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
| Keywords: | Science & Technology, Technology, Energy & Fuels, Materials Science, Multidisciplinary, Materials Science, intercalation, vanadyl phosphate, pillar effect, ion exchange, interlayer expansion, cathode, sodium-ion battery, POSITIVE ELECTRODE, HIGH-VOLTAGE, PERFORMANCE, NA3V2(PO4)3, STORAGE, NAVOPO4 |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Chemistry |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10191748 |
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