Improved performances of lithium carbonate coated graphite in the piperidinium-based hybrid electrolyte for lithium-ion battery

The lithium carbonate (Li₂CO₃)-coated carbon microbead composites (LCO/CMB-T) with the coating amount of 1.07, 2.88, and 7.39% are prepared by the impregnation process (IP). Three LCO/CMB-T samples are first used in the piperidinium-based hybrid electrolyte. It is found that the long charge–discharge cycles did not result in the decomposition or exfoliation of Li₂CO₃ coating. They can effectively prevent graphite electrode from exfoliation and suppress the graphite/electrolyte interfacial reaction. In three tested samples (IP-1.07%, IP-2.88% and IP-7.39% for short), the IP-2.88% sample showed the best cell performances and the highest capacity retention (82.9%) after 50 cycles. This work gives a new design method for the application of graphite materials in the ionic liquid-based electrolyte.