Highly efficient synthesis of nano-Si anode material for Li-ion batteries by a ball-milling assisted low-temperature aluminothermic reduction
Highly efficient synthesis of nano-Si anode material for Li-ion batteries by a ball-milling assisted low-temperature aluminothermic reduction
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DOI：
10.1016/j.electacta.2019.135346
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发表时间：
2020-01
影响因子：
6.6
通讯作者：
Dao-lai Fang;Yicheng Zhao;Shanshan Wang;Taishun Hu;Cui-hong Zheng
中科院分区：
文献类型：
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作者：
Dao-lai Fang;Yicheng Zhao;Shanshan Wang;Taishun Hu;Cui-hong Zheng
以白色炭黑和粗颗粒铝粉为原料，在NaCl/KCl/AlCl 3共晶体系中，采用球磨辅助低温铝热还原法，在150-180 °C下制备了纳米硅负极材料。将球磨辅助铝热还原时间延长至10 h后，硅的产率可达94%。合成的纳米硅主要由粒径小于50 nm的超细原生颗粒构成的不规则多孔团聚体组成。纳米硅阳极具有上级电化学性能。在0.05 A g− 1的电流密度下，其最大放电和充电容量分别为3075和2597 mAh g−1，导致84.5%的高初始库仑效率。纳米硅阳极在0.2 A g−1下表现出2458 mAh g− 1的可逆容量，在5 A g−1的高电流密度下表现出1169 mAh g− 1的可逆容量。在1 A g− 1下循环400次后，它仍然提供了804 mAh g−1的高可逆容量。该合成策略不仅简单高效，而且成本低，环境友好，因此有望用于下一代锂离子电池纳米Si负极材料的大规模生产。
A nano-sized Si anode material was synthesized by a novel and highly efficient route of ball-milling assisted low-temperature aluminothermic reduction at 150–180 °C in a eutectic NaCl/KCl/AlCl3mixture, using white carbon black and coarse-grained Al powder as the starting materials. After extending the duration of ball-milling assisted aluminothermic reduction to 10 h, the obtained Si yield reached as high as 94%. The synthesized nano-Si mainly consisted of irregular porous agglomerates constructed by ultrafine primary particles with a particle size less than 50 nm. The nano-Si anode showed a superior electrochemical performance. Its maximum discharge and charge capacities at a current density of 0.05 A g−1were 3075 and 2597 mAh g−1, respectively, leading to a high initial Coulumbic efficiency of 84.5%. The nano-Si anode exhibited reversible capacities of 2458 mAh g−1at 0.2 A g−1, and of 1169 mAh g−1at a high current density of 5 A g−1. After cycling at 1 A g−1for 400 cycles, it still delivered a high reversible capacity of 804 mAh g−1. The synthetic strategy, which is not only facile and highly efficient, but also low-cost and environmentally benign, is thus promising to be applied for mass production of nano-Si anode materials for next-generation Li-ion batteries.