Department of Materials Science and Engineering, Department of Energy and Resources Engineering, and Beijing Key Laboratory for Theory and Technology of Advanced Battery Materials, College of Engineering, Peking University , Beijing, 100871, China.
ACS Nano. 2016 Jan 26;10(1):1648-54. doi: 10.1021/acsnano.5b07367. Epub 2015 Dec 24.
One of the biggest challenging issues of carbon nanomaterials for Li ion batteries (LIBs) is that they show low initial Coulombic efficiency (CE), leading to a limited specific capacity. Herein, we demonstrate a simple template self-volatilization strategy for in situ synthesis of mesoporous carbon nanotube/Ag nanoparticle (NP) hybrids (Ag-MCNTs) to boost the LIBs' performance. The key concept of Ag-MCNTs for enhancing LIBs is that a small trace of Ag NPs on MCNTS can greatly restrict the formation of a thicker solid electrolyte interphase film, which has been well verified by both transmission electron microscopy results and quantum density functional theory calculations, leading to the highest initial CE in all the reported carbon nanomaterials. This uncovered property of Ag NPs from Ag-MCNTs makes them exhibit a very high reversible capacity of 1637 mAh g(-1) after 400 discharge/charge cycles at 100 mA g(-1), approximately 5 times higher than the theoretical value of a graphite anode (372 mAh g(-1)), excellent rate capability, and long cycle life.
对于锂离子电池(LIBs)而言,碳纳米材料面临的最大挑战之一是其初始库仑效率(CE)较低,导致比容量有限。在此,我们展示了一种简单的模板自挥发策略,用于原位合成介孔碳纳米管/Ag 纳米颗粒(NP)杂化物(Ag-MCNTs),以提高 LIBs 的性能。Ag-MCNTs 提高 LIBs 性能的关键概念是,MCNTs 上少量的 Ag NPs 可以极大地限制较厚固体电解质界面膜的形成,这已通过透射电子显微镜结果和量子密度泛函理论计算得到了很好的验证,导致在所有报道的碳纳米材料中具有最高的初始 CE。Ag-MCNTs 中 Ag NPs 的这种特性使它们在 100 mA g(-1)的电流密度下经过 400 次充放电循环后表现出非常高的可逆容量 1637 mAh g(-1),约为石墨阳极(372 mAh g(-1))理论值的 5 倍,具有优异的倍率性能和长循环寿命。