Kinetic and Interfacial Characterization of Lithium Electrodes in Organic Electrolyte Solutions

鋰電極在有機電解質溶液中的電極動力及界面特性表徵

張裕祺(Yu-Chi Chang) ； 鍾志華(Jyh-Hwa Jong) ； 費定國(George Ting-Kuo Fey)

《Journal of the Chinese Institute of Chemical Engineers》 35卷4期 (2004/07) Pp. 425-433

https://doi.org/10.6967/JCICE.200407.0425

摘要

本研究以電流脈動法及定電荷階躍法測求鋰電極在若干重要的鋰二次電池有機電解質溶液中的動力學參數，如極化電阻，交換流密度及電荷轉移係數。所探討的溶液系統為EC-DEC混合溶劑及PC溶劑與相應LiPF6、LiCLO4、LiBF4等電解質之組合。另外亦測求界面電容值。就1M LiCLO4/PC及1M LiPF6/EC-DEC(1:1)的量測結果言，所測得之值與文獻所載相近。研究結果顯示鋰在1M LiPF6/EC-DEC溶液中的極化電阻隨浸放時間變化甚緩，但在1M LiPF6/PC溶液中則增加甚速。又界面電容則在各溶液中皆隨浸放時間延長降低。本研究亦以微圓盤電極探究鋰在1M LiPF6/PC-DEC溶液中的電化學沉積及溶解程序，並測求擴散係數。

並列摘要

Kinetic parameters, such as polarization resistance, exchange current density, and transfer coefficient, for lithium electrodes in a few important lithium battery electrolyte solutions were determined at 27℃ using the galvanostatic pulse technique and constant charge-step method. The solvents used were ethylene and diethyl carbonates mixtures and propylene carbonate. The electrolytes used were LiPF6, LiClO4, and LiBF4. The electrode capacitance was also measured. The effects of the electrolyte concentration and storage time on the polarization resistance and the electrode capacitance were examined. The data obtained for lithium in 1 M LiClO4/PC and 1 M LiPF6/EC-DEC(1:1) electrolyte solutions are consistent with those reported in the literature. During two days of storage, the polarization resistance of the lithium in the 1 M LiPF6/EC-DEC solutions only increased slightly, but the polarization resistance of the lithium in the 1 M LiPF6/PC solutions increased remarkably. The electrode capacitance, however, decreased during prolonged storage for the systems studied. A nickel microdisk electrode was also used to study the electrodeposition and electrodissolution of lithium in the 1 M LiPF6/EC-DEC (1:1) electrolyte solutions. The diffusion coefficient was also determined.

並列關鍵字

Lithium electrode ； Organic electrolytes ； Kinetics ； Electrode capacitance ； Diffusivity