Improved rate performance of amorphous carbon coated lithium zinc titanate anode material with alginic acid as carbon precursor and particle size controller

Abstract

Carbon-coated Li2ZnTi3O8 composites with nano particle size and excellent rate performance are synthesized via a facile solid-state reaction route using alginic acid as carbon precursor. The results of characterization indicate that amorphous carbon layer is homogeneously coated on the surface of Li2ZnTi3O8 particles without any crystal structure change. The carbon-coated Li2ZnTi3O8 composite with 10wt.% alginic acid (Li2ZnTi3O8/C-10) shows the largest initial discharge specific capacity of 242.5, 190.0, 165.2 and 91.2mAhg−1 can be obtained after 100 cycles at 0.1, 0.5, 1.0 and 2.0Ag−1, respectively. EIS reveals that Li2ZnTi3O8/C-10 exhibits higher electronic conductivity and faster lithium ion diffusivity. The significant improvements of electrochemical performance are attributed to the carbon layer on the outer surface of Li2ZnTi3O8 active particles, which can restrain the growth of particles, enhance electronic conductivity and suppress electrolyte decomposition.