Electrochemical characteristics of Ge incorporated Li4Ti5O12 as an anode for Li-ion battery applications

Lithium titanate (LTO) is recognized to be a promising anode material for lithium-ion batteries due to its remarkable structural benefits. However, the poor electronic conductivity and lower capacity hindered its widespread commercialization. To analyze the possibility of enhancing the performance of LTO through doping, pristine LTO (Li4Ti5O12), as well as germanium (Ge4+) doped LTO (Li4GexTi5-xO12; x = 0.1 and 0.2) were synthesized by conventional solid-state reaction. Characterizations confirmed the partial replacement of Ti4+ by Ge4+ evenly throughout the material without making any stress or deformation to the host lattice. The electrochemical characterization results established that the presence of germanium effectively reduced the cell impedance as well as improved Li+ ion diffusion. The doping was able to enhance capacity compared to pristine LTO. The best of the doped compositions (Li4Ge0.1Ti4.9O12) was able to deliver a capacity of 159 mA h g(-1) at 0.1 C rate and 145 mA h g(-1) at 1 C with more than 85 % retention after 300 cycles.