Ag4V2O6F2: An Electrochemically Active and High Silver Density Phase

Low-temperature hydrothermal techniques were used to synthesize single crystals of Ag4V2O6F2.
This previously unreported oxide fluoride phase was characterized by single-crystal X-ray diffraction and
IR spectroscopy and was also evaluated as a primary lithium battery cathode. Crystal data:  monoclinic,
space group P21/n (No. 14), with a = 8.4034(4) Å, b = 10.548(1) Å, c = 12.459(1) Å, β = 90.314(2)°, and
Z = 4. Ag4V2O6F2 (SVOF) exhibits two characteristic regions within the discharge curve, an upper plateau
at 3.5 V, and a lower sloped region around 2.3 V from reduction of the vanadium oxide fluoride framework.
The material has a nominal capacity of 251 mAh/g, with 148 mAh/g above 3 V. The upper discharge plateau
at 3.5 V is nearly 300 mV over the silver reduction potential of the commercial primary battery material,
Ag2V4O11 (SVO).

采用低温水热技术合成了Ag4V2O6F2的单晶。该先前未报道的氧化物氟化物相通过单晶X射线衍射和红外光谱进行了表征，并也被评估为锂离子电池正极材料。晶体数据：单斜晶系，空间群P21/n（编号14），晶胞参数为a = 8.4034(4) Å，b = 10.548(1) Å，c = 12.459(1) Å，β = 90.314(2)°，Z = 4。Ag4V2O6F2（SVOF）在放电曲线上表现出两个特征区域，一个为3.5 V处的上平顶区，另一个为约2.3 V处的下斜坡区，这是由于钒氧化物氟化物框架的还原所致。该材料的理论容量为251 mAh/g，其中3 V以上的容量为148 mAh/g。3.5 V处的上放电平顶区相对于商业正极材料Ag2V4O11（SVO）的银还原电位高出近300 mV。