The electrochemical insertion properties of sodium vanadium fluorophosphate, Na3V2(PO4)2F3
The electrochemical insertion properties of sodium vanadium fluorophosphate, Na3V2(PO4)2F3
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DOI：
10.1016/j.ssi.2006.07.028
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发表时间：
2006-07-01
影响因子：
3.2
通讯作者：
Barker, J.
中科院分区：
文献类型：
--
作者：
Gover, R. K. B.;Bryan, A.;Barker, J.
介绍了氟磷酸钒钠盐Na3V2(PO4)(2)F-3的结构和碱性离子插入特性。该材料是由前驱体VPO4和NaF采用固态碳热还原法制备的。Na3V2(PO4)(2)F-3相在3.0-4.6Vvs.Li的电势范围内的电化学表征表明，结构电压响应对应于每个分子式单位两个碱离子的可逆循环。相关的比容量约为120mAhg，平均放电电压约为4.1V对Li。长期的循环实验证实了碱性离子插入反应的稳定性，在最初的220次循环中，容量衰减很小。电压漂移到5V对Li表明，所有三个Na离子都可以成功地从氟磷酸盐相中提取出来，尽管这个过程可能伴随着一些同时的结构降解。(C)2006爱思唯尔B.V.保留所有权利。
The structural and alkali ion insertion characteristics of sodium vanadium fluorophosphate, Na3V2(PO4)(2)F-3 are presented. The material was prepared using a solid-state carbothermal reduction approach involving the precursors VPO4 and NaF. Electrochemical characterization of the Na3V2(PO4)(2)F-3 phase in the potential range 3.0-4.6 V vs. Li, revealed a structured voltage response corresponding to the reversible cycling of two alkali ions per formula unit. The associated specific capacity was around 120 mAh/g, at an average discharge voltage of around 4.1 V vs. Li. The stability of the alkali ion insertion reactions was confirmed by long term cycling experiments, which demonstrated low capacity fade over the initial 220 cycles. Voltage excursions to 5 V vs. Li suggest that all three Na ions may be successfully extracted from the fluorophosphate phase, although this process is likely accompanied by some concurrent structural degradation. (c) 2006 Elsevier B.V. All rights reserved.