Micron-sized, carbon-coated Li4Ti5O12 as high power anode material for advanced lithium batteries

Abstract

Spherical, high tap density, carbon-coated Li4Ti5O12 powders are synthesized by a spray-drying process followed by a facile pitch coating. XRD, SEM, TEM analyses show that the carbon layer uniformly coats the Li4Ti5O12 particles without producing any crystalline changes. We demonstrate that the carbon coating significantly increases the electrical conductivity of Li4Ti5O12 making it an efficient, high rate electrode for lithium cells. The electrochemical tests in fact confirm that the 3.25 wt% carbon-coated Li4Ti5O12 electrode operates with ultra high rate capacity levels, i.e., 100 C and has excellent capacity retention and charge-discharge efficiency for a life extending over 100 cycles.