Optimizing anode performance using Silicon nanoparticle to Li₄Ti₅O₁₂ as prepared by hydrothermal mechanochemical process with Li₂CO₃ as lithium ion source

Lithium titanat Lithium titanate (Li₄Ti₅O₁₂)/LTO is one of more favourable materials to be used as anode electrode to replace graphite in Li-ion battery application. The LTO has a crystal structure that is more stable than graphite, and undergoes less strain during lithium intercalation process. However, along with the increasing demand for batteries with high performance, the capacity of LTO also needs to be increased, among others by combining with a high capacity material, i.e: silicon, which theoretical capacity can reach 4200 mAh/g, but with volumetric strain of 300%. To minimize volume expansion effect, nano-scale silicon particle is used to form the LTO/Si nano-composite. This research is carried out to synthesize the spinel LTO prepared by hydrothermal and mechanochemical process from xerogel TiO₂. During preparation of slurry mixture of active material to make anode sheet, the LTO is mixed with silicon nano-particle at 5%, 10% and 15% by weight. The coin cell type battery is assembled with lithium metal as the counter electrode. The material characterization instruments used are X-Ray diffraction (XRD) and Transmission Electron Microscope (TEM) with Energy Dispersive Spectrometer (EDS) showing the elements mapping. The battery performance is tested using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and charge discharge (CD). From EIS testing, the conductivity values of the samples decrease along with the increasing weight of Si nano-particles. The CV test shows that the highest capacity of 197.09 mAh/g is achieved on the sample with 5wt% Si-nano. The CD test shows that this LTO/Si nano-composite is capable to withstand at high charge/discharge rate at until 12 C exceeding the electric car battery requirement at 10 C.