▎ 摘　　要

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.%, similar to 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 degrees C, respectively. The initial coulombic efficiencies of both paper and grid anode ate 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. (C) 2016 Elsevier Ltd. All rights reserved.