CAJ | 학술논문

Sn基合金负极材料具有高达990 mAh?g-1的理论比容量，但其也存在因脱嵌锂过程发生巨大的体积变化而导致循环性能较差的问题。本文以Sn、Fe、石墨为原料利用简易的高能球磨法成功制备了具有核壳结构的FeSn2-C复合物，系统研究了球磨时间、FeSn2相含量对材料物相结构及电化学性能的影响，并分析了电极的失效机理。研究表明，球磨时间的增加有利于FeSn2金属间化合物相的形成及材料颗粒的细化，进而有利于材料比容量的增加及循环性能的提升；FeSn2相含量的增加能够提高FeSn2-C材料的比容量，但会降低FeSn2-C电极的循环稳定性。经工艺优化及组分调节，球磨24 h合成的Sn20Fe10C70材料具有最优的电化学性能，材料的比容量在540 mAh?g-1左右，并能稳定循环100次，是一种非常有发展前途的锂离子电池高比容量负极材料。
Sn기합금부겁재료구유고체990 mAh?g-1적이론비용량，단기야존재인탈감리과정발생거대적체적변화이도치순배성능교차적문제。본문이Sn、Fe、석묵위원료이용간역적고능구마법성공제비료구유핵각결구적FeSn2-C복합물，계통연구료구마시간、FeSn2상함량대재료물상결구급전화학성능적영향，병분석료전겁적실효궤리。연구표명，구마시간적증가유리우FeSn2금속간화합물상적형성급재료과립적세화，진이유리우재료비용량적증가급순배성능적제승；FeSn2상함량적증가능구제고FeSn2-C재료적비용량，단회강저FeSn2-C전겁적순배은정성。경공예우화급조분조절，구마24 h합성적Sn20Fe10C70재료구유최우적전화학성능，재료적비용량재540 mAh?g-1좌우，병능은정순배100차，시일충비상유발전전도적리리자전지고비용량부겁재료。
Tin has a theoretical specific capacity as high as 990 mAh?g-1, and is thus a potential anode material for high-energy-density lithium-ion batteries. However, it suffers from a huge volume change during lithiation/delithiation process, leading to poor cycle performance. In this paper, core/shel structured FeSn2-C composites were successful y synthesized by a simple high-energy bal mil ing technique with Sn, Fe, and graphite powder as raw materials. The FeSn2-C composite was evaluated as an anode material for lithium-ion batteries. The influence of mil ing time and final phase composition on the microstructure and electrochemical performance of FeSn2-C composites was systematically investigated. The failure mechanism of the FeSn2-C electrode was also analyzed. The results reveal that long mil ing time can promote the mechanical al oying process of the FeSn2 phase and reduce the particle size of the FeSn2-C composite, which are beneficial for the increase of the specific capacity and the improvement of the cycle performance of the FeSn2-C electrode. A high FeSn2 phase content leads to a high specific capacity of the FeSn2-C composites but poor cycling stability of the electrode. The optimized Sn20Fe10C70 composite prepared by bal mil ing for 24 h (500 r?min-1) shows the best electrochemical performance with a capacity about 540 mAh?g-1 for 100 cycles. The synthesized Sn20Fe10C70 composite is a promising anode material for high-energy-density lithium-ion batteries.