Chemical welding of diamine molecules in graphene oxide nanosheets: Design of precisely controlled interlayer spacings with the fast Li+ diffusion coefficient toward high-performance storage application

A facile method of chemical welding was proposed to construct the diamine molecules (xDM, x = 2, 3, 4, 6 and 8) pillared- and strained-graphene oxides (GO) with controllable interlayer spacing via the dehydration condensation reaction between GO and xDM. The interlayer spacing of xDM pillared- and strained-GO (GO-xDM) is controllably enlarged by choosing the length of xDM, which determines the pillaring effects. The GO-xDM exhibits a low diffusion barrier and ultrafast Li+ diffusion dynamics due to its enlarged interlayer spacing, which leads the excellent Li+ storage rate capability. The effects of interlayer spacing on Li+ diffusion dynamics are clarified that GO-2DM with the interlayer spacing of 0.911 nm displays the excellent Li+ storage performance and fast Li+ diffusion dynamics (D-Li(+) = 2.4 x10(-7) cm(2) s(-1)). The GO-2DM presents a high capacity of 291.8 mAh g(-1) at a current density of 0.1 A g(-1) and a high-rate capability of 120.8 mAh g(-1) at a current density of 5.0 A g(-1). The GO-2DM//AC lithium-ion hybrid capacitor delivers a high energy density of 103.6 Wh kg(-1) at a power density of 55.8 W kg(-1), even reaches 2777.8 W kg(-1) at a power density of 61.1 Wh kg(-1). The approach of chemical welding provides a novel perspective for controllably enlarging interlayer spacing and designing two-dimensional (2D) energy storage materials with high-rate capability. (c) 2021 Published by Elsevier Ltd.

Automated summary

The facile chemical welding method proposed in this study allows for the construction of two-dimensional energy storage materials with controllable interlayer spacing, leading to excellent Li+ storage performance and fast Li+ diffusion dynamics. By choosing the length of xDM, the interlayer spacing of GO-xDM can be enlarged, enhancing the Li+ diffusion rate and energy storage capability.