In situ catalytic growth 3D multi-layers graphene sheets coated nano-silicon anode for high performance lithium-ion batteries

By Mingshan Wang, Guoliang Wang, Shuai Wang, J. Zhang, Jing Wang, W. Zhong, Fangyu Tang, Zhenliang Yang, Jianming Zheng, Xing Li. Chemical Engineering Journal, 2019

156 citations recorded by the source corpus.

Abstract Silicon (Si) has been considered as the next generation ideal anode material for lithium-ion batteries because of its highest theoretical capacity (4200 mAh·g−1) and affluent reserves in nature. However, the severe volume expansion and unstable solid electrolyte interface (SEI) film of Si electrode during lithiation/delithiation, as well as the poor electron conductivity have seriously restricted its commercial application. In this work, in situ catalytic growth graphene on the surface of nano-Si (Si@Graphene) composite is successfully developed through a novel electroless deposition approach with Ni as the catalyst. The as-prepared Si@Graphene composite exhibits excellent cycling stability and rate capability, which retains a reversible discharge capacity up to 1909 mAh g−1 after 100 cycles at 0.2 A g−1, and is able to deliver a discharge capacity of 975 mAh g−1 even at a high current density of 52 A g−1. The results indicate that a folded multi-layers graphene could be uniformly grown on the nano-Si particles by permeating the Ni catalytic layer using the triethylene glycol (triglycol) as carbon source. The folded multi-layers graphene could maintain the framework structure of the composite during the electrochemical cycling for its excellent mechanical performance and outstanding flexibility, which could relieve volume expansion/shrinkage of Si during repeated Li+ intercalation/extraction. Moreover, the strong connection between the graphene and nano-Si in three dimensional also could provide abundant transport pathway for the electron transportation to the surface of Si particles. The most important thing is that the multi-layer graphene could protect the nano-Si particles from being directly exposed to the electrolyte, which is beneficial for maintaining the stability of SEI films.

Subfields: Electrical and Electronic Engineering, Electronic, Optical and Magnetic Materials

View Paper: https://www.semanticscholar.org/paper/3d4e9a1e8aec9dfe01650d8004d212ce76b50059