An In-depth analysis of the electrochemical processing parameters for monolithic solid electrolyte interphase (SEI) formation at Ti-SiOx@C anode for high performance Lithium-ion batteries
Nayoung Kang, Hyeon-Woo Yang, Woo Seung Kang, Sun-Jae Kim
In this article, we analyzed the effect of the electrochemical processing parameters on the formation of the uniform and dense SEI, so-called monolithic SEI, at Ti-SiOx@C anode, related with the improvement of initial Columbic efficiency and cyclic stability. The SEI microstructure and morphology are found to be strongly influenced primarily by the extent of current density and its duration time applied for the initial charging of the electrode. The monolithic SEI is shown to be created by applying a threshold amount of charge of 0.68 mAh at a high current density of 70 A g−1 necessary enough for the active nucleation and electrolytic reactions. As a result, the NCM811||Ti-SiOx@C full cells fabricated with the monolithic SEI anode showed a significantly improved initial Coulombic efficiency of 82.0% from 70.4% for the conventional SEI anode. At the same time, the cyclic stability was also found to be much enhanced from the comparison of capacity retention; 76.2% for the monolithic SEI anode and 58.1% for the conventional SEI anode, respectively.