论文部分内容阅读
根据同时平衡原理和质量守恒原理,推导Ni(II)-Co(II)-C2O42--NH3-NH4+-H2O反应体系中金属离子和草酸盐在常温水溶液中的热力学平衡方程,计算并绘制该体系的lg[Me2+]T—pH图。结果表明,在水溶液中,当pH值小于5.0时,溶液中镍离子和钴离子以设定配比转移到前驱体粉末中,前驱体的形貌为粒状聚集体;当pH值大于5.0时,由于Ni(NH3)n2+和Co(NH3)n2+(n=1-6)离子的形成,前驱体粉末中镍钴配比不能维持料液中设定的配比值,前驱体在pH为5.0-8.0范围内呈现棒状形貌,而在pH>8.0时为纤维状形貌。改变沉淀介质可以在pH为2.0-8.6范围内获得配比准确、成分均匀的纤维状镍钴合金前驱体。
According to the principle of simultaneous equilibrium and mass conservation, the thermodynamic equilibrium equations of metal ions and oxalate in aqueous solution at Ni (II) -Co (II) -C2O42-NH3-NH4 + -H2O were deduced and calculated Lg [Me2 +] T-pH plot of the system. The results show that when the pH value is less than 5.0, the nickel ions and cobalt ions in the solution are transferred to the precursor powder in a set ratio, and the morphology of the precursor is granular aggregates. When the pH value is greater than 5.0, Due to the formation of Ni (NH3) n2 + and Co (NH3) n2 + (n = 1-6) ions, the ratio of Ni and Co in the precursor powder can not maintain the ratio set in the feed solution. Within the range of rod-like morphology, and when pH> 8.0 for the fibrous morphology. Change the precipitation medium can be obtained in the pH range of 2.0-8.6 accurate, uniform composition of fibrous Ni-Co precursor.