Shanmukaraj Devaraj, Kretschmer Katja, Sahu Tuhin, Bao Weizhai, Rojo Teofilo, Wang Guoxiu, Armand Michel
Electrochemical Energy storage group, CIC Energigune, Parque Tecnológico de Álava, 48, 01510, Miñano, Álava, Spain.
Centre for Clean Energy Technology, Faculty of Science, University of Technology, Sydney, Ultimo, New South Wales, 2007, Australia.
ChemSusChem. 2018 Sep 21;11(18):3286-3291. doi: 10.1002/cssc.201801099. Epub 2018 Aug 7.
The development of sodium-ion batteries has been hindered so far by the large irreversible capacity of hard carbon anodes and other anode materials in the initial few cycles, as sodium ions coming from cathode materials is consumed in the formation of the solid-electrolyte interface (SEI) and irreversibly trapped in anodes. Herein, the successful synthesis of an environmentally benign and cost-effective sodium salt (Na C O ) is reported that could be applied as additive in cathodes to solve the irreversible-capacity issues of anodes in sodium-ion batteries. When added to Na (VO) (PO ) F cathode, the cathode delivered a highly stable capacity of 135 mAh g and stable cycling performance. The water-stable Na (VO) (PO ) F cathode in combination with a water-soluble sacrificial salt eliminates the need for using any toxic solvents for laminate preparation, thus paving way for greener electrode fabrication techniques. A 100 % increase in capacity of sodium cells (full-cell configuration) has been observed when using the new sodium salt at a C-rate of 2C. Regardless of the electrode fabrication technique, this new salt finds use in both aqueous and non-aqueous cathode-fabrication techniques for sodium-ion batteries.
到目前为止，钠离子电池的发展受到硬碳负极和其他负极材料在最初几个循环中存在的较大不可逆容量的阻碍，这是因为来自正极材料的钠离子在固体电解质界面（SEI）形成过程中被消耗，并不可逆地被困在负极中。在此，报道了一种环境友好且具有成本效益的钠盐（Na₂C₂O₄）的成功合成，它可作为正极添加剂来解决钠离子电池负极的不可逆容量问题。当添加到Na₃(VO)₂(PO₄)₂F正极中时，该正极展现出135 mAh g的高度稳定容量以及稳定的循环性能。水稳定的Na₃(VO)₂(PO₄)₂F正极与水溶性牺牲盐相结合，无需使用任何有毒溶剂来制备层压板，从而为更环保的电极制造技术铺平了道路。当以2C的倍率使用这种新钠盐时，钠离子电池（全电池配置）的容量提高了100%。无论采用何种电极制造技术，这种新盐都可用于钠离子电池的水性和非水性正极制造技术中。
