Dongxiao Wang , Na Su , Zhuo-Er Yu , Shigang Lu , Yingchun Lyu , Bingkun Guo
{"title":"Reaction mechanisms of NASICON-type Na4MnV(PO4)3/C as a cathode for sodium-ion batteries","authors":"Dongxiao Wang , Na Su , Zhuo-Er Yu , Shigang Lu , Yingchun Lyu , Bingkun Guo","doi":"10.1016/j.elecom.2023.107651","DOIUrl":null,"url":null,"abstract":"<div><p>NASCION-type Na<sub>4</sub>MnV(PO<sub>4</sub>)<sub>3</sub>/C was synthesized through a <em>sol</em>–<em>gel</em> method. Two Na<sup>+</sup> ions can reversibly (de)intercalation from/into the unit structure, with a reversible capacity of 106.7 mAh/g. The charge–discharge curves show a voltage slope at 3.4 V, and a plateau at 3.6 V. To elucidate the sodium storage mechanisms, the structure evolution and electron transfer are demonstrated using <em>in-situ</em> X-ray diffraction and <em>ex-situ</em> X-ray absorption spectroscopy. It is found that at different stage of the electrochemical process, it undergoes different phase reaction process with different redox couples. A single-phase reaction occurs when the first sodium-ion extracted from Na<sub>4</sub>MnV(PO<sub>4</sub>)<sub>3</sub> with a V<sup>3+</sup>/V<sup>4+</sup> redox, while a two-phase reaction takes place when the second sodium-ion extracted with a Mn<sup>2+</sup>/Mn<sup>3+</sup> redox. Galvanostatic intermittent titration technique, GITT, indicates the single-phase reaction process shows a faster kinetic compared to the two-phase reaction process. These findings between the kinetics, chemical and structural evolution provide new insight into the sodium storage mechanisms of NASICON-type cathode, and further the understanding of other materials for sodium-ion batteries.</p></div>","PeriodicalId":304,"journal":{"name":"Electrochemistry Communications","volume":null,"pages":null},"PeriodicalIF":4.7000,"publicationDate":"2023-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1388248123002266/pdfft?md5=2aa52b083a0b1d782af6fc0014874936&pid=1-s2.0-S1388248123002266-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Electrochemistry Communications","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1388248123002266","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ELECTROCHEMISTRY","Score":null,"Total":0}
引用次数: 0
Abstract
NASCION-type Na4MnV(PO4)3/C was synthesized through a sol–gel method. Two Na+ ions can reversibly (de)intercalation from/into the unit structure, with a reversible capacity of 106.7 mAh/g. The charge–discharge curves show a voltage slope at 3.4 V, and a plateau at 3.6 V. To elucidate the sodium storage mechanisms, the structure evolution and electron transfer are demonstrated using in-situ X-ray diffraction and ex-situ X-ray absorption spectroscopy. It is found that at different stage of the electrochemical process, it undergoes different phase reaction process with different redox couples. A single-phase reaction occurs when the first sodium-ion extracted from Na4MnV(PO4)3 with a V3+/V4+ redox, while a two-phase reaction takes place when the second sodium-ion extracted with a Mn2+/Mn3+ redox. Galvanostatic intermittent titration technique, GITT, indicates the single-phase reaction process shows a faster kinetic compared to the two-phase reaction process. These findings between the kinetics, chemical and structural evolution provide new insight into the sodium storage mechanisms of NASICON-type cathode, and further the understanding of other materials for sodium-ion batteries.
期刊介绍:
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