| With the demand of high-performance lithium-ion batteries （LIBs）, the anode materials with high capacity and cyling stability have been investigated intensively. In comparsion with commercial carbonaceous materials, silicon exhibits high theoretical specific capacity (4200 mAh g-1), which is considered as the potential alternative anode materials for LIBs. However, the large volume changes （> 300%） during the discharge/charge process may bring damage of the electrode, which results in poor cycling life. Thus, the rational design of Si/porous graphene structure that can alleviate volumetric expansion and increase the conductivity has become the key strategy to push forward the practical application of Si based anodes. In this work, the Si/porous reduced graphene oxide （rGO） composite films have been fabricated and their electrochemical performances have been investigated. The main innovative results are listed as follows:（1） A honeycomb silicon/rGO composite film on Cu substrate is synthesized by the "breath figure" method. As a anode material for LIBs, the honeycomb rGO structure can effectively prevent the agglomeration of the silicon nanoparticles and reduce the transfer resistance of Li+. The composite film on Cu substrate without polymer binders can also increase the electrical conductivity. The composite film anode presents a high specific capacity and good cycling stability, as well as an enhanced rate capability, and presents high specific capacity of 1118 mAh g-1 at 50 mA g-1 up to 50 cycles. This approach to fabricated such a honeycomb porous structure is a low-cost and facile route for silicon-based anode materials.（2） A novel of Si/porous rGO composite film is fabricated by steam etching of Si/rGO aerogel. The rGO sheets with nano-holes build a unique three-dimensional porous network and can encapsulate the Si nanoparticles. The porous structure of Si/rGO composite can reduce the transfer distance of Li ions and restrain the aggregation and destruction of Si particles. And the double hydrothermal process can improve the electrode conductivity. The composite film electrode presents a high specific capacity of 1004 mAh g-1 at 50 mA g-1 up to 100 cycles.（3） A self-supported Si/porous rGO composite film is synthesized by evaporation and leavening method. The condensed and smooth stable silicon/GO hydrosol film was first obtained at the liquid/air interfac in the thermostatted water bath. After leavening of hydrazine monohydrate, a porous Si/rGO composite film was obtained. The porous structure as a buffer base can effectively release the volume expansion of the silicon particles, increase the electrical conductivity and reduce the transfer resistance of Li ions. The self-supported composite film electrode can reduce the internal resistance between the copper substrate and active materials. The simple methode provide some guidance to flexible energy storage devices. The self-supported Si/porous rGO composite film presents a high specific capacity of 1261 mAh g-1 at 50 mA g-1 up to 70 cycles, as well as enhanced rate capability.（4） A self-supported Si/Ag NWs/rGO integrated composite film is fabricated by introducing binary conductive networks （Ag NWs and rGO） into Si active materials with the help of a facile vacuum-filtration method. The Si/Ag/rGO composite film can maintain the structural stability and reduce the charge-transfer resistance during the charging and discharging processes. The flexible Si/Ag/rGO integrated composite electrode presents improved electrochemcal performances, it delivers a high specific capacity of 1269 mAh g-1 at 50 mA g-1 up to 50 cycles.（5） Using in situ electrochemistry in a high-resolution transmission electron microscopy, we demonstrate the lithiation behavior of Si/rGO composite. The composite structure can effectively release the volume expansion of the silicon particles, increase the electrical conductivity and avoide the phenomenon of electrochemical reunion. |
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