Jeong Soon-Ki, Kim Jin Hee, Jeong Yoon-Taek, Kim Yang Soo
J Nanosci Nanotechnol. 2016 Mar;16(3):3049-53. doi: 10.1166/jnn.2016.11065.
This study examined the electrochemical deposition and dissolution of lithium on nickel electrodes in propylene carbonate (PC) electrolytes containing different concentrations of lithium salts, including LiN(SO2C2F5)2 or LiPF6. The electrode reactions were significantly affected by the electrolyte concentration. The cyclability of the electrodes was considerably improved by increasing the electrolyte concentration. X-ray photoelectron spectroscopy (XPS) showed that the composition of the solid electrolyte interphase (SEI) was also affected by the electrolyte concentration. The SEI formed in the 1st cycle consisted mainly of LiF in 1 and 2.15 M LiN(SO2C2F5)2/PC solutions. After the 30th cycle in the former solution, there was a large decrease in the amount of LiF and a large increase in the amount of LiOH. On the other hand, in the latter solution there was a smaller decrease and a smaller increase in the amount of LiF and LiOH, respectively, as compared to the former solution after the 30th cycle.
本研究考察了锂在含有不同浓度锂盐（包括双（三氟甲基磺酰）亚胺锂（LiN(SO2C2F5)2）或六氟磷酸锂（LiPF6））的碳酸丙烯酯（PC）电解质中在镍电极上的电化学沉积和溶解情况。电极反应受到电解质浓度的显著影响。通过提高电解质浓度，电极的循环性能得到了显著改善。X射线光电子能谱（XPS）表明，固体电解质界面（SEI）的组成也受到电解质浓度的影响。在1和2.15 M LiN(SO2C2F5)2/PC溶液中，第1次循环形成的SEI主要由LiF组成。在前一种溶液中第30次循环后，LiF的量大幅减少，LiOH的量大幅增加。另一方面，与前一种溶液在第30次循环后相比，在后一种溶液中LiF和LiOH的量分别有较小的减少和增加。
