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采用磁悬浮感应熔炼及退火处理的方法,制备La1.9Ti0.1MgNi9合金。对合金样品的XRD、PCT和电化学测试表明,所有样品均由多相组成,LaNi5相为主相。当退火温度达到1173K时,合金中LaMg2Ni9相消失,Ti2Ni相出现。退火处理能提高合金的晶化程度、降低吸放氢平台压。退火1073K合金的有效吸氢量较高,在303K时达到1.25%(质量分数)。La1.9Ti0.1MgNi9合金退火后,放电容量、循环稳定性以及高倍率放电性能得到极大改善,以1173K退火合金电化学性能较好,其最大放电容量为377mAh/g,1100mA/g电流密度下的高倍率放电性能为0.839,经112次充放电循环后放电容量保持率为60%。
La1.9Ti0.1MgNi9 alloy was prepared by magnetic induction induction melting and annealing treatment. XRD, PCT and electrochemical tests on the alloy samples show that all the samples are composed of heterogeneous phases, and LaNi5 phase is the main phase. When the annealing temperature reached 1173K, the alloy disappeared LaMg2Ni9 phase, Ti2Ni phase appears. Annealing treatment can improve the degree of crystallization of the alloy and reduce the pressure on the platform for hydrogen absorption and desorption. The effective hydrogen absorption of annealed 1073K alloy is higher, reaching 1.25% (mass fraction) at 303K. After annealing, the discharge capacity, cycle stability and high rate discharge performance of La1.9Ti0.1MgNi9 alloy have been greatly improved. The electrochemical properties of 1173K annealed alloy are better. The maximum discharge capacity of La1.9Ti0.1MgNi9 alloy is 377mAh / g at current density of 1100mA / g The high-rate discharge performance was 0.839. After 112 charge-discharge cycles, the discharge capacity retention rate was 60%.