Rationally designed rGO@CNTs@CNFs film as self-supporting binder-free Si electrodes for high-performance lithium-ion batteries

Abstract

Si has become the most promising anode materials for lithium-ion batteries (LIBs) due to its high theoretical specific capacity and comparable low discharge potential. However, the practical usage of Si is still hindered by its huge volume expansion. To release volume stress and improve conductance, designed self-supporting binder-free Si electrode endowed with three-dimensional structure has been come up in this research. The pore structure is adjusted by rationally designing the proportion of carbon nanotubes (CNTs) and carbon nanofibers (CNFs) to alleviate volume change. Simultaneously, construct stable conductivity network was fabricated via ice crystal self-assemble freezing technique following compress and carbonization process. The electrochemical specific capacity of rGO@CNTs@CNFs@Si-2 electrode has stably remained at 2250 mAh/g after 100 cycles (100 mA/g) with benign rate capabilities. This simple self-assemble method for self-supporting binder-free Si electrode would open a new route to exploit high energy density Si-based electrode for flexible LIBs.

Keywords: Aerogel; Binder-free; Lithium-ion batteries; Self-supporting; Si electrodes.