| 초록 |
The demands for lithium-ion batteries increase in many industrial fields, such as electric vehicles, energy storage systems, and mobile electronic devices. Graphite has been generally used as an anode material in LIBs because of its low cost, high reversible charge-discharge capacity, and low potential versus Li/Li+. However its structure can be destroyed during the charge/discharge process. A lithium fluoride (LiF), one of the solid electrolyte interphase components, is chemically and thermally stable for the LIBs. In this study, the two types of C-F bonds (semi-ionic and covalent bonds) were investigated which one is the key factor to generate the LiF after charging step. To evaluate the cycle stability, assembled coin-cell was charge-discharge steps for 100 cycles at 1 C-rate. The LiF is mainly observed in the semi-ionic graphite than pristine and covalent bond graphite. Thus, the semi-ionic C-F bonds can form the LiF on the anode surface, and then it improves the cycle stability. |
