Embedding nano-Li4Ti5O12 in hierarchical porous carbon matrixes derived from water soluble polymers for ultra-fast lithium ion batteries anodic materials

Abstract

Li4Ti5O12/hierarchical porous carbon matrixes composites are successfully prepared by a facile and fast polymers assisted sol-gel method, aiming to promote both electronic and ionic conductivity. As indicated by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis, three less expensive cost and available water soluble polymers (e.g. PAA, CMC, and SA) can homogeneously react with Li-Ti-O precursor to incorporate into interior of nano-scale lithium titanate and provide a continues conductive network after pyrolysis. In addition, the results of scanning electron microscopy and transmission electron microscopy also prove that the Li4Ti5O12 nanoparticles are firmly embedded in porous carbon matrix with no obvious agglomeration. EIS measurement and cyclic voltammetry further reveal that the facilitated electrode kinetics and better ionic transport of Li4Ti5O12/hierarchical porous carbon matrixes composites than that of Li4Ti5O12. The c-CMC-LTO exhibits a superior capacity of 92 mAh g-1 and retains its initial value with no obviously capacity decay over 200 cycles under an ultra-high C rate (50 C).