Binder-free graphene/carbon nanotube/silicon hybrid grid as freestanding anode for high capacity lithium ion batteries

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• 作者：Zhen-Dong Huang^a ; ¹ ; ^{hzd0506127@gmail.com" class="auth_mail" title="E-mail the corresponding author} ; Kun Zhang^a ; ¹ ; Ting-Ting Zhang^a ; Rui-Qing Liu^a ; Xiu-Jing Lin^a ; Yi Li^a ; Xiao-Miao Feng^a ; Qun-Bo Mei^a ; Titus Masese^b ; Yan-Wen Ma^a ; ^{iamywma@njupt.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Wei Huang^a ; ^c
• 关键词：A. Graphene ; A. Energy materials ; A. Nanocomposites ; A. Sandwich structures
• 刊名：Composites Part A: Applied Science and Manufacturing
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：84
• 期：Complete
• 页码：386-392
• 全文大小：2425 K

文摘

Light-weight graphene/Si (G/Si) hybrid binder-free electrode is deemed a high energy density anode contender for lithium ion batteries (LIBs). However, paper-like G/Si electrodes tend to show an increased migration distance for Li⁺ through the fast interlayer channel with the increment of electrode size, in addition to an intrinsically slow diffusion kinetics; thereby encumbering their commercial realisation in high energy density and long life LIBs. To address these problems, herein, sandwich-structured graphene/carbon nanotube/silicon (G/CNT/Si, Si: 56 wt.%, ∼500 nm) hybrid grid is designed, cognizant of its uniform and shorter Li⁺ migration distance. Cyclic voltammograms indicate G/CNT/Si paper and grid anode to exhibit good electrochemical activity at both low and high temperatures. Noteworthy is that the Li⁺ diffusion coefficient ratio between G/CNT/Si grid and paper anodes are 1.82, 1.64, 1.43, 1.36 and 1.53 at a temperature of −5, 10, 25, 40 and 55 °C, respectively. The initial coulombic efficiencies of both paper and grid anode are as high as ∼82%. After 60 cycles at 420 mA g⁻¹, the charge capacity of G/CNT/Si grid is retained at 808 mA h g⁻¹, which by far surpasses that of paper anode (i.e., 490 mA h g⁻¹). The attained lithium ion storage performance at both high and low temperatures, underpins the G/CNT/Si sandwiched grid as effective to realise the practical deployment of paper-like graphene electrodes for high energy density and long life LIBs.