用熔体快淬法制备Al70-xSi30Mnx(x=0,3,7)合金,测定其差示扫描量热(DSC)曲线,将快淬带分别在523、593、673K进行时效,分析时效对相组成以及与锂离子电池相关的电化学性能的影响。结果表明:熔体快淬Al-Si-Mn合金中形成过饱和固溶体。当时效温度为523K以上时,从过饱和固溶体中析出α-Si;当时效温度为593K时,形成Al/Si/Mn三元化合物。Mn明显提高过饱和固溶体的过饱和度,并使过饱和固溶体相对于Al-Si二元系更稳定。样品经673K时效4h后,在充放锂过程中会发生明显粉化,电化学循环性能较过饱和态明显劣化。
Al70-xSi30Mnx(x=0,3,7,mole fraction,%) ribbons were prepared by melt spinning.The differential scanning calorimetry(DSC) curves of the ribbons were measured.The ribbons were annealed at 523,593 and 673 K,respectively.The phase constitutions and the electrochemical performances responsible to Li-ion batteries properties were analyzed.The results show that α-Si will precipitate from the supersaturated solid solution when the temperature is 523 K,and the Al/Si/Mn ternary intermetallic compound forms after the melt-spun ribbons are heated to 593 K.The addition of Mn can increase the supersaturation degree of solid solution,and the supersaturated solid solution is more stable compared with the Al70Si30 binary alloy.When the ribbons are annealed at 673 K for 4 h,a pulverization can clearly be observed during Li charging and discharging.As a result,the electrochemical cycling performance will fad much rapidly compared with as-quenched ribbons.