کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
192537 | 459744 | 2008 | 9 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Uncommon potential hysteresis in the Li/Li2xVO(H2−xPO4)2 (0 ≤ x ≤ 2) system Uncommon potential hysteresis in the Li/Li2xVO(H2−xPO4)2 (0 ≤ x ≤ 2) system](/preview/png/192537.png)
Physical and electrochemical investigations of vanadium phosphates, Li2xVO(H2−xPO4)2 (0 < x < 2), have been undertaken. H+/Li+ ionic exchange from VO(H2PO4)2 to Li2VO(HPO4)2 leads to grain decrepitation. Further ionic exchange toward formation of Li4VO(PO4)2 lowers the symmetry. As inferred from potentiodynamic cycling correlated to ex situ and in situ X-ray diffraction (XRD), the system Li/Li4VO(PO4)2 shows several phase transformations that are associated with thermodynamical potential hysteresis that span from roughly 15 mV to more than 1.8 V. Small hysteresis are associated with topotactic reactions and with VV/VIV and VIII/VII redox couples. Large potential hysteresis values (>1 V) were observed when oxidation of VIII to VIV is involved.
Journal: Electrochimica Acta - Volume 53, Issue 13, 20 May 2008, Pages 4564–4572