Electrochemical performance of pre-lithiated graphite as negative electrode in lithium-ion capacitors

• Published in: Russian journal of electrochemistry Vol. 50; no. 11; pp. 1050 - 1057
• Main Authors: Yuan, Meirong, Liu, Weiqiang, Zhu, Yongfa, Xu, Yongjin
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.11.2014
• Subjects: Chemistry; Chemistry and Materials Science; Electrochemistry; Physical Chemistry; lithium-ion capacitor; Li pre-doping; electrochemical impedance spectroscopy; graphite electrode; Li intercalation
• ISSN: 1023-1935; 1608-3342
• DOI: 10.1134/S1023193514020086

Electrochemical performance of the pre-lithiated graphite and the as-assembled lithium-ion capacitors (LICs) were investigated within the Li/graphite two-electrode cell and activated carbon (AC)/graphite two-electrode cell, respectively. The morphologies of the electrodes were characterized by scanning electron microscopy (SEM). The Li intercalation of Li/graphite two-electrode cell was performed using short circuiting and galvanostatic charging techniques. The Li pre-doping process was characterized by electrochemical impedance spectroscopy (EIS). The cycle performance of the LICs were investigated at the rates of 1–20 C between the cut-off voltage at 2 to 4 V. The results demonstrated that the LIC cells with 8 h pre-doping time have the best cycle performance at the high rate of 10 C. Li pre-doping methodology plays a crucial role in the electrochemical performance of the graphite electrode and the as-assembled LICs.