Preparation of V doped lanthanum silicate electrolyte ceramics by combustion method and study on conductance mechanism |
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Authors: | Shi Chen Zhi Liang Huang Chang Lian Chen Mian Lu Chang Sheng Wu Yuan Jiang |
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Affiliation: | School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan, China |
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Abstract: | Vanadium doped La9.33Si6?xVxO26+0.5x (x = 0.5, 1.0, 1.5) (LSVO) electrolyte powder was prepared by combustion method at 600°C for 5-7 min. The powder was sintered at 1500°C for 3 hours to prepare LSVO ceramics. XPS, IR, XRD, and EIS analysis show that V5+ doping replaces Si4+ in SiO4] to form Si(V)O4] tetrahedron. With the increase in x, the lattice volume increase. When x = 2.0, the LaVO4 phase was formed, indicating that the limit doping amount of V5+ replacing Si4+ is x ≤ 1.5. The conductivity of LSVO increases significantly with the increase in x (x ≤ 1.0), which attributed to the defect reaction caused by V5+ doping. The addition of the interstitial oxygen Oi* in 63 channels and the increase of lattice volume leads to increased conductivity. When x = 1.0, the highest conductivity is 1.46 × 10?2 S·cm?1 (800°C). The doping enhancement conductivity mechanism is the Interstitial oxygen defect-Lattice volume composite enhancement mechanism. |
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Keywords: | combustion synthesis doping enhancement conductivity mechanism lanthanum silicate solid electrolyte ceramics vanadium doping |
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