Electrochemical characteristics of porous TiO2 encapsulated silicon anode

TiO2 coated silicon, which was prepared by the modified sol–gel method, was employed as the anode material for lithium secondary batteries and the relationship between the diffusivity and electrochemical characteristics was investigated. The results showed that the physical properties of the samples, such as their diffusivity and pore size distribution, enhanced the cycling efficiency of the TiO2 coated silicon, probably due to the reduction of the side reactions, which may be closely related to the pore size distribution of the TiO2 coating layer. The pore size of the coating layer plays an important role in retarding the lithium ion diffusion. In the experimental range studied herein, higher capacity retention was exhibited for the TiO2 coated silicon prepared at pH 10.7.

Graphical abstractCycling performances of the TiO2 coated silicon anode at different catalyst pH values.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► TiO2 coated silicon was used as the anode material for lithium batteries. ► TiO2 layer acted as a buffer layer for reducing the volume expansion. ► Pore size distribution of TiO2 coated silicon influenced discharge capacity. ► Higher capacity retention was exhibited at pH 10.7.