其對電化學(xué)性能的影響
(1. 西安交通大學(xué) 金屬材料強(qiáng)度國家重點(diǎn)實驗室，西安 710049；
2. 西安交通大學(xué) 物質(zhì)非平衡合成與調(diào)控教育部重點(diǎn)實驗室，西安 710049)
摘 要: 用熔體快淬法制備Al70−xSi30Mnx(x=0，3，7)合金，測定其差示掃描量熱(DSC)曲線，將快淬帶分別在523、593、673 K進(jìn)行時效，分析時效對相組成以及與鋰離子電池相關(guān)的電化學(xué)性能的影響。結(jié)果表明：熔體快淬Al-Si-Mn合金中形成過飽和固溶體。當(dāng)時效溫度為523 K以上時，從過飽和固溶體中析出α-Si；當(dāng)時效溫度為593 K時，形成Al/Si/Mn三元化合物。Mn明顯提高過飽和固溶體的過飽和度，并使過飽和固溶體相對于Al-Si二元系更穩(wěn)定。樣品經(jīng)673 K時效4 h后，在充放鋰過程中會發(fā)生明顯粉化，電化學(xué)循環(huán)性能較過飽和態(tài)明顯劣化。
關(guān)鍵字: Al-Si-Mn合金；熔體快淬；時效；電化學(xué)性能
during annealing and its effect on electrochemical property
（1. State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China;
2. Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter,
Ministry of Education, Xi’an Jiaotong University, Xi’an, 710049, China）
Abstract: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.
Key words: Al-Si-Mn alloys; melt spinning; ageing; electrochemical property
