| Abstrakt: |
Lithium vanadyl phosphate has seven different crystallographic phases. Among them, α‐LiVOPO4is chosen because of its relatively high energy density and redox voltage of 3.9 V compared to the other phosphates. In this study, Ti4+‐doped α‐LiV1−xTixOPO4(x= 0.00, 0.003, 0.005, 0.007, and 0.01) was prepared using a sol–gel method to increase the structure stability and electrochemical performance. The triclinic structure with the space group P‐1 was confirmed by X‐ray diffraction, Fourier‐transform infrared spectroscopy, and X‐ray photoelectron spectroscopy. Inductively coupled plasma–optical emission spectroscopy was conducted to determine the precise state. The shape and size of the particles were observed by field‐emission scanning electron microscopy. In situX‐ray absorption spectroscopy was performed to confirm the structural behavior during the electrochemical reaction. Electrochemical measurements such as cyclic voltammetry and galvanostatic charge–discharge were conducted. α‐LiV1−xTixOPO4(x= 0.003, 0.005, 0.007, and 0.01) showed structural stability during cycling as well as decreased polarization during charge and discharge with the increased diffusion coefficient of lithium ions. α‐LiV0.995Ti0.005OPO4showed the best cycling stability and rate capability among all the samples examined because Ti doping retained its site to prevent structural collapse. |
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