Synthesis of Lithium Titanium Oxide-Based Composite As Anode Material for High Performance Lithium Ion Batteries

Rechargeable lithium ion batteries are regarded as reliable energy storage and supply systems for large scale applications due to their long cycle life, high gravimetric and volumetric energy densities, and low self-discharge rate. On this subject, spinel lithium titanium oxide Li₄Ti₅O₁₂ (LTO) is a commercially successful “zero-strain” Li-ion intercalation anode material, whose present large scale application is limited by its low theoretical capacity of 175 mAh g⁻¹ at a high operation potential of 1.55 V vs Li+/Li. In the present study, we try to incorporate silicon (Si) nanoparticles into the LTO host matrix by using a high energy ball milling process under inert atmosphere, since Si has the highest known specific capacity of 4200 mAh g⁻¹, and boost the conductive properties of the electrode through addition of polyacrylonitrile (PAN) conductive polymer. As a result, a combination of LTO, Si and PAN will supplement each other and afford a composite anode materials with a superior Li-ion storage capacity, enhanced conductivity and excellent mechanical properties. For instance, LTO/Si/PAN composite with weight ratio of 25:25:50 showed initial capacity of 2150 mAh∙g^-1, and after 30 cycles capacity was 1200 mAh∙g^-1 at a current density of 50 mA∙g^-1, when cycled between 0 and 3 V (vs. Li⁺/Li).