Improving Rate Capability of Li-Ion Capacitors Using Nano Graphite Anodes

Sunday, 28 May 2017: 15:20
Grand Salon C - Section 15 (Hilton New Orleans Riverside)
A. R. Aref, S. W. Chen, M. T. Lanagan, C. A. Randall, and R. Rajagopalan (The Pennsylvania State University)
Li-ion capacitors are receiving considerable attention as potential energy storage device due to their high power density, high energy density, as well as long cycle life. The energy density of the capacitor is determined by the specific capacitance of high surface area double layer carbon cathodes while the power performance is dependent upon the rate capability of the anode. In this investigation, we demonstrate a high energy density lithium ion capacitor that can be charged and discharged between 2.2V – 4.2V with energy density exceeding 100 Wh/kg based on both the masses of the electrode and discharge time < 1 min can be fabricated. The capacitor was capable of being cycled at 1 A/g with 90% capacitance retention over 5000 cycles. The high voltage stability of the capacitor upto 4.2V was also determined using an accelerated floating voltage tests. The high performance of the capacitor was due to the use of a high purity polymer derived carbon cathode with controlled pore size distribution along with a nanocrystalline prelithated graphite as the anode.