Bamboo carbon assisted sol-gel synthesis of Li4Ti5O12 anode material with enhanced electrochemical activity for lithium ion battery

To control the morphology of inorganic electrode materials for high performance lithium ion batteries, bamboo carbon with highly ordered three-dimensional microscopic porosity was employed to act as a template to confine the growth of spinel Li4Ti5O12 anode nanoparticle in its sol-gel synthesis. The bamboo carbon was removed by high temperature calcination thereafter to produce pure spinel Li4Ti5O12 (BC-LTO). The electrochemical properties of BC-LTO were thoroughly evaluated in lithium ion batteries and compared with the electrochemical properties of the spinel Li4Ti5O12 synthesized without bamboo carbon template (P-LTO). The crystal structures of BC-LTO and P-LTO were identified as the same spinel structure by X-ray diffraction. The positive effects of adding bamboo carbon during the electrode synthesis were observed to be reducing both the particle size and size distribution of BC-LTO as evidenced by scanning electron microscopy (SEM). Cyclic voltammetry (CV) analysis demonstrated that BC-LTO had a higher lithium insertion/extraction reversibility than P-LTO. The BC-LTO anode delivered a capacity of 160 mAh g−1 after 50 cycles at a rate of 0.2 C, much higher than the P-LTO anode which only delivered 139 mAh g−1 under the same conditions. Detailed galvanostatic charge/discharge tests using various current rates were carried out, and the results demonstrated that BC-LTO is a promising candidate anode material for high performance lithium ion batteries. The bamboo carbon assisted sol-gel method was therefore proven to be effective in our study, and should be able to be applied to other electrochemical systems.