Correlating Graphite Surface with Interphase for Fast-Charging and Low-Temperature Operation

The properties of graphite surface can not only affect the interaction between graphite and electrolyte but also induce the formation of solid electrolyte interphase (SEI) film. Herein, the graphite surface is purposely treated to incorporate oxygen-containing functional groups, which facilitates a desired Li2CO3-rich SEI with high ionic conductivity and good mechanical stability. The modified graphite electrodes exhibit significant enhancement in electrochemical performance during rapid charging at the rate of 15 C, where an impressive capacity of 225 mAh g(-1) is still maintained, corresponding to a capacity retention of 60.8%. Moreover, the modified electrodes showcase outstanding performance under wide temperature ranging from -50 to +65(degrees)C, with an amazing capacity retention of 97.6% under -20 C-degrees, the conceivable capacity of 105 mAh g(-1) at -50 C-degrees as well as excellent stability at both -20 C-degrees and +65 C-degrees. These findings offer valuable insights into the design of a thin and robust Li2CO3-rich SEI layer via a facile chemical treatment of the graphite surface.