Lithium-ion capacitors: Electrochemical performance and thermal behavior

• Published in: Journal of power sources 2013-12, Vol.243, p.982-992
• Main Authors: Smith, Patricia H., Tran, Thanh N., Jiang, Thomas L., Chung, Jaesik
• Format: Article
• Language: English
• Subjects: Accelerating rate calorimetry; Applied sciences; Asymmetric capacitor; Capacitors. Resistors. Filters; Differential scanning calorimetry; Electrical engineering. Electrical power engineering; Electrochemical double-layer capacitor; Exact sciences and technology; Lithium-ion capacitor; Various equipment and components
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2013.06.012

We report on the electrochemical performance of 500F, 1100F, and 2200F lithium-ion capacitors containing carbonate-based electrolytes. First and second generation lithium-ion capacitors were cycled at temperatures ranging from −30°C to 65°C, with rates from 5C to 200C. Unlike acetonitrile-based electric double-layer capacitors, whose performance has been reported to be relatively insensitive to temperatures between −30°C and 40°C, lithium-ion capacitor performance degrades at low temperatures and displays characteristics typical of a lithium-ion battery. Three-electrode lithium-ion capacitor cycling tests revealed that reduced capacity at low temperatures is due to the polarization of the lithiated, negative electrode. The self-discharge of cells at the various temperatures was studied and compared to an electric double-layer capacitor and a lithium-ion battery cell. Lithium-ion capacitors and batteries were observed to have significantly lower self-discharge rates than electric double-layer capacitors. Accelerating rate calorimetry and differential scanning calorimetry were used to assess the thermal runaway behavior of full cells along with the thermal properties of the cell components. Our study showed that the thermal behavior of the lithium-ion capacitor is in between those of an electric double-layer capacitor and a lithium-ion battery. •LICs display the best characteristics of both LIBs and EDLCs at 10–40°C.•LICs electrochemical performance similar to LIBs at low temperatures.•LICs self-discharge similar to LIB at 40°C.•ARC and DSC reveal LICs thermal behavior characteristic of both LIB and EDLC.