Impact of carbon coating processing using sucrose for thick binder-free titanium niobium oxide lithium-ion battery anode

Abstract

Lithium-ion batteries are increasingly important for providing energy storage solutions. In the drive to improve the energy density at the cell level, optimizing the electrode architecture is crucial in addition to researching new materials. Binder-free (BF) electrodes include porous pellets only containing battery electroactive materials. These electrodes can provide advantages with regard to mechanical stability and alleviated ion transport limitations relative to composite approaches for very thick and energy-dense electrodes. However, the absence of conductive additives often limits suitable material candidates for BF battery electrodes. TiNb2O7 (TNO) is a promising BF electrode material from a gravimetric and volumetric capacity standpoint, but phase pure TNO has relatively low electronic conductivity. Herein, a sucrose precursor coating method for TNO materials was implemented to process the TNO materials into BF electrodes. The sucrose served as a source to generate carbon in the electrodes, where the carbon coating resulted in an increase in rate capability, discharge voltage, and cycle life.