Tuning the graphitization of the carbon coating layer on LiFePO4 enables superior properties

Abstract

Lithium iron phosphate (LFP) with carbon coating has been widely used as cathode material for lithium ion battery, however its electrochemical properties are still limited by the inadequate electrical conductivity of the carbon shell. Herein, through synthesis optimization, the graphitization of the carbon layer has been successfully tuned, resulting in the production of LFP samples coated with carbon exhibiting higher graphitization. Concomitant with this modification, an improved conductive network has been fabricated within the secondary particles of the LFP sample. Compared to the pristine sample, the modified sample showed an approximately 21.3 % increase in capacity retention after 235 cycles at 2C. Graphitization tuning of the carbon coating layer provides a new method to further unlock the electrochemical potential of the LFP cathode material.