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Nano/Microstructured Silicon–Graphite Composite Anode for High-Energy-Density Li-Ion Battery
ACS Nano ( IF 15.8 ) Pub Date : 2019-02-13 00:00:00 , DOI: 10.1021/acsnano.9b00169
Peng Li 1 , Jang-Yeon Hwang 1 , Yang-Kook Sun 1
Affiliation  

With the ever-increasing demand for lithium-ion batteries (LIBs) with higher energy density, tremendous attention has been paid to design various silicon-active materials as alternative electrodes due to their high theoretical capacity (ca. 3579 mAh g–1). However, totally replacing the commercially utilized graphite with silicon is still insurmountable owing to bottlenecks such as low electrode loading and insufficient areal capacity. Thus, in this study, we turn back to enhanced graphite electrode through the cooperation of modified silicon via a facile and scalable blending process. The modified nano/microstructured silicon with boron doping and carbon nanotube wedging (B–Si/CNT) can provide improved stability (88.2% retention after 200 cycles at 2000 mA g–1) and high reversible capacity (∼2426 mAh g–1), whereas the graphite can act as a tough framework for high loading. Owing to the synergistic effect, the resultant B–Si/CNT–graphite composite (B–Si/[email protected]) shows a high areal capacity of 5.2 mAh cm–2 and excellent cycle retention of 83.4% over 100 cycles, even with ultrahigh active mass loading of 11.2 mg cm–2,which could significantly surpass the commercially used graphite electrode. Notably, the composite also exhibits impressive application in Li-ion full battery using 2 mol % Al-doped full-concentration-gradient Li[Ni0.76Co0.09Mn0.15]O2 (Al2-FCG76) as the cathode with excellent capacity retention of 82.5% even after 300 cycles and an outstanding energy density (8.0 mWh cm–2) based on the large mass loading of the cathode (12.0 mg cm–2).

中文翻译:

用于高能量密度锂离子电池的纳米/微结构硅石墨复合阳极

随着对具有更高能量密度的锂离子电池(LIB)的不断增长的需求,由于其理论容量高(约3579 mAh g –1),人们已非常重视设计各种硅活性材料作为替代电极。然而,由于瓶颈例如低的电极负载和不足的面积容量,用硅完全替代商业上使用的石墨仍然是不可克服的。因此,在这项研究中,我们将通过一种简便且可扩展的混合过程,通过改性硅的合作,再回到增强型石墨电极。带有硼掺杂和碳纳米管楔合(B–Si / CNT)的改性纳米/微结构硅可以提供更高的稳定性(在200 mA g –1的200次循环后保持88.2%的保留率))和高可逆容量(约2426 mAh g –1),而石墨则可以充当高负载的坚硬骨架。由于具有协同效应,所得的B–Si / CNT–石墨复合材料(B–Si / [电子邮件保护])显示出5.2 mAh cm –2的高面积容量,即使在100次循环下仍具有83.4%的出色循环保持率11.2 mg cm -2的超高活性物质负载,这可能会大大超过商业上使用的石墨电极。值得注意的是,该复合材料在使用2摩尔%Al掺杂的全浓度梯度Li [Ni 0.76 Co 0.09 Mn 0.15 ] O 2的锂离子全电池中也显示出令人印象深刻的应用。(AL2-FCG76)作为即使经过300次循环的82.5%优异的容量保持率在阴极和杰出的能量密度(mWh的8.0厘米-2)的基础上,阴极的大质量负载(12.0毫克厘米-2)。
更新日期:2019-02-13
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