Structural Analysis and Electrochemical Studies of Carbon Coated Li4Ti5O12 Particles Used as Anode for Lithium-Ion Battery

Carbon coated Li4Ti5O12 (C-LTO) particles have been synthesized by hydrothermal method and high-temperature calcination process. Nanostructure and carbon-coating has been characterized in detail by X-ray diffraction (XRD), high resolution TEM (HR-TEM), selected electron diffraction (SAED), and scanning transmission X-ray microscopy (STXM) combined with X-ray absorption near edge structure (XANES) spectroscopy. The prepared particles are comprised of highly crystalline spinel-type Li4Ti5O12 with the size range of 20-70 nm. HR-TEM imaging and STXM-XANES spectromicrocopy confirmed the amorphous carbon layer uniformly covered on the surface of single LTO particles with optimized content and coating thickness (~5 nm). The electrochemical performance of C-LTO particles as an anode in lithium-ion batteries is evaluated, demonstrating both improved rate capability and cycling performance, which was attributed to the enhanced electron transport/high electrical conductivity and fast lithium-ion insertion/extraction, as a result of uniform and optimized amorphous carbon coating on the C-LTO particles.