Flexible Silicon/Titanium Dioxide/Reduced Graphene Oxide Self-Standing Electrode with High Performance and High Stability for Lithium-Ion Batteries
Peng Su, Yu Zhou, Jian Wu, Jin Shao, Liming Shen, Ningzhong Bao
Abstract
The great volume expansion and unstable nature of the solid electrolyte interface film of silicon (Si) are central issues that obstruct the advancement of the Si-based electrode despite its high theoretical capacity and abundant resources. Here a kind of flexible silicon/titanium dioxide/reduced graphene oxide (Si/TiO 2 /rGO) self-standing electrode is constructed without the assistance of a binder and conductive agent. Briefly, the Si nanoparticle is coated with TiO 2 via a sol–gel process, and then the core–shell structured Si/TiO 2 is assembled with GO using chitosan as the cross-linker followed by freeze-drying, pressing, and annealing at an ammonia/argon (NH 3 /Ar) atmosphere. In this structure, TiO 2 and rGO provide dual protection for Si, and a continuous conductive path is formed. Additionally, nitrogen doping by NH 3 and chitosan further strengthens the lithium storage performance. The fabricated Si/TiO 2 /rGO film electrode demonstrates excellent rate performance over a broad range of current densities and keeps a reversible capacity of 1333.8 mAh g –1 after 200 cycles operated at 200 mA g –1 .