一种简易合成稳定和高倍率性能Si/NiSix/CNTs锂离子负极材料的方法
一种简易合成稳定和高倍率性能Si/NiSix/CNTs锂离子负极材料的方法
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作者：
Fan Xu;Ji Jingjing;Jiang Xiangping;Wang Wei;Liu ZhaoPing
硅（Si）/碳纳米管（CNT）复合材料是锂离子电池的理想负极材料。然而，由于Si和CNT之间较大的体积膨胀不匹配，通过不同方法制备的传统Si/CNT复合材料的循环寿命仍然非常有限。在这里，在均匀嵌入的镍纳米粒子的帮助下，通过化学气相沉积方法成功设计和制造了一种新型硅/镍硅合金（NiSix）/碳纳米管复合材料。碳纳米管从复合材料中生长出来并充当坚固的铆钉，这大大提高了硅和碳纳米管之间界面的电连接稳定性。因此，相应的放电容量可以保持在550mAh g-1左右，300次循环后容量保持率为84%，同时在4 A g-1下放电容量为420mAh g-1，可以实现高倍率性能。
Silicon (Si)/carbon nanotubes (CNTs) composites are ideal anode materials for lithium ion batteries. However, due to the large volume expansion mismatch between Si and CNTs, the cycle life of conventional Si/CNTs composites fabricated by different approaches is still very limited. Here, a novel Si/nickel-Si alloy (NiSix)/CNTs composite has been successfully designed and fabricated through a chemical vapor deposition method with the assistance of uniformly embedded Ni nanoparticles. The CNTs grow up from the composite and serve as strong rivets, which greatly improves the electrical connection stability at the interface between Si and CNTs. Consequently, the corresponding discharge capacity can remain at around 550 mA h g-1 with a capacity retention of 84% for 300 cycles, while a high rate capability can be achieved with a discharge capacity of 420 mA h g-1 at 4 A g-1.