采用铜模铸造法制备了V3TiNi0.56Co0.3钒基贮氢合金,并进行物相组成、显微组织、电化学腐蚀性能和电化学循环稳定性能的测试与对比分析。结果表明,铜模铸造制备的V3Ti Ni0.56Co0.3钒基贮氢合金为非晶合金,显著改善了合金的电化学腐蚀性...采用铜模铸造法制备了V3TiNi0.56Co0.3钒基贮氢合金,并进行物相组成、显微组织、电化学腐蚀性能和电化学循环稳定性能的测试与对比分析。结果表明,铜模铸造制备的V3Ti Ni0.56Co0.3钒基贮氢合金为非晶合金,显著改善了合金的电化学腐蚀性能和电化学循环稳定性能。与常规铸造相比,铜模铸造使其腐蚀电位正移389 m V、最大放电容量增大19.96%、充放电循环20次后的放电容量下降率从96.93%减小至40.22%。展开更多
为了有效提高铸态钒基固溶体储氢合金的电化学性能,分别采用三种不同的铸造工艺制备了V_3TiNi_(0.56_Sc_(0.1)钒基固溶体储氢合金铸态试样,并进行了显微组织观察以及电化学循环稳定性和电化学腐蚀性能的测试与分析。结果表明:与常规铸...为了有效提高铸态钒基固溶体储氢合金的电化学性能,分别采用三种不同的铸造工艺制备了V_3TiNi_(0.56_Sc_(0.1)钒基固溶体储氢合金铸态试样,并进行了显微组织观察以及电化学循环稳定性和电化学腐蚀性能的测试与分析。结果表明:与常规铸造法相比,静置辅助铸造法和双重辅助铸造法有利于改善合金的铸造质量,细化合金晶粒,提高合金的电化学循环稳定性和电化学腐蚀性能,且双重辅助铸造法效果更佳;静置辅助铸造法、双重辅助铸造法分别使放电容量衰减率减小47%、71%,分别使合金的腐蚀电位正移109、237 m V。展开更多
NaxCoO2 is a commonly used cathode material for sodium ion batteries because of its easy synthesis, high reversible capacity and good cyclability. The structural and electrochemical properties of NaxCoO2 during sodium...NaxCoO2 is a commonly used cathode material for sodium ion batteries because of its easy synthesis, high reversible capacity and good cyclability. The structural and electrochemical properties of NaxCoO2 during sodium ion insertion/extraction process are studied based on first principles calculations. The calculation results of crystal structure parameters and average intercalation voltage are in good agreement with experiment data. Through calculation of the geometric structure and charge transfer in charging and discharging processes of NaxCoO2, it is found that the oxygen atom surrounding Co of the CoO6 octahedral screens the coulomb potential produced by sodium vacancy in NaxCoO2, and the charge is removed from the entire Co-O layer instead of the Co atom adjacent to sodium vacancy when sodium ions are extracted from the Na CoO2 lattice. Thus, during the insertion/extraction of sodium ion from Na CoO2, the CoO6 octahedral structure undergoes small lattice distortion, which makes the local structure quite stable and is beneficial to the cycling stability of the material for the application of sodium ion batteries.展开更多
文摘采用铜模铸造法制备了V3TiNi0.56Co0.3钒基贮氢合金,并进行物相组成、显微组织、电化学腐蚀性能和电化学循环稳定性能的测试与对比分析。结果表明,铜模铸造制备的V3Ti Ni0.56Co0.3钒基贮氢合金为非晶合金,显著改善了合金的电化学腐蚀性能和电化学循环稳定性能。与常规铸造相比,铜模铸造使其腐蚀电位正移389 m V、最大放电容量增大19.96%、充放电循环20次后的放电容量下降率从96.93%减小至40.22%。
文摘为了有效提高铸态钒基固溶体储氢合金的电化学性能,分别采用三种不同的铸造工艺制备了V_3TiNi_(0.56_Sc_(0.1)钒基固溶体储氢合金铸态试样,并进行了显微组织观察以及电化学循环稳定性和电化学腐蚀性能的测试与分析。结果表明:与常规铸造法相比,静置辅助铸造法和双重辅助铸造法有利于改善合金的铸造质量,细化合金晶粒,提高合金的电化学循环稳定性和电化学腐蚀性能,且双重辅助铸造法效果更佳;静置辅助铸造法、双重辅助铸造法分别使放电容量衰减率减小47%、71%,分别使合金的腐蚀电位正移109、237 m V。
基金Project(51472211)supported by the National Natural Science Foundation of ChinaProject(2012CK1006)supported by Scientific and Technical Achievement Transformation Fund of Hunan Province,China
文摘NaxCoO2 is a commonly used cathode material for sodium ion batteries because of its easy synthesis, high reversible capacity and good cyclability. The structural and electrochemical properties of NaxCoO2 during sodium ion insertion/extraction process are studied based on first principles calculations. The calculation results of crystal structure parameters and average intercalation voltage are in good agreement with experiment data. Through calculation of the geometric structure and charge transfer in charging and discharging processes of NaxCoO2, it is found that the oxygen atom surrounding Co of the CoO6 octahedral screens the coulomb potential produced by sodium vacancy in NaxCoO2, and the charge is removed from the entire Co-O layer instead of the Co atom adjacent to sodium vacancy when sodium ions are extracted from the Na CoO2 lattice. Thus, during the insertion/extraction of sodium ion from Na CoO2, the CoO6 octahedral structure undergoes small lattice distortion, which makes the local structure quite stable and is beneficial to the cycling stability of the material for the application of sodium ion batteries.
