Titanium dioxide and carbon co-modified lithium manganese silicate cathode materials with improved electrochemical performance for lithium ion batteries

• A new composite of TiO2 and carbon co-modified Li2MnSiO4 has been successfully prepared for the first time.
• 3 wt% TiO2 coated Li2MnSiO4/C displays the highest discharge capacity of 186.4 mAh g− 1 at 0.1C.
• TiO2 and carbon co-coated on the surface of Li2MnSiO4 can alleviate the structural collapse and Mn dissolution.

A new composite of TiO2 and carbon co-coated Li2MnSiO4 has been successfully prepared for the first time. The influence of TiO2 on the structure and electrochemical performance is investigated by means of XRD, SEM, TEM, EDS, EIS and galvanostatic charge–discharge tests. The results indicate that TiO2 and carbon have been successfully coated on the surface of Li2MnSiO4 without altering its orthorhombic structure. When assembled as cathode, the electrochemical performance is significantly improved after coating TiO2. Specially, 3 wt.% TiO2 coated Li2MnSiO4/C can display a discharge capacity of 186 mAh g− 1 at 0.1 C, and 78 mAh g− 1 is remained after 25 cycles at 0.5 C. This excellent electrochemical performance is due to the reason that TiO2 and carbon hybrid layer are coated on the surface of Li2MnSiO4, which can alleviate the structural collapse and Mn dissolution in the electrolyte during charge–discharge process. In addition, the smaller charge transfer resistance and the larger lithium ion diffusion coefficient also contribute to the superior electrochemical performance.