Different types of pre-lithiated hard carbon as negative electrode material for lithium-ion capacitors.
writer：Jin Zhang, Xifeng Liu, Jing Wang, Jingli Shi, Zhiqiang Shi
keywords：Lithium-ion capacitors， Hard carbon ，Pre-lithiation Plateau Potential range
source：期刊
specific source：Electrochimica Acta.
Issue time：2015年
Lithium-ion capacitors (LICs) are assembled with activated carbon (AC) cathode and pre-lithiated hard carbon (HC) anode. Two kinds of HC materials with different physical and electrochemical behaviors have been investigated as the negative electrodes for LIC. Compared with spherical HC, the irregular HC shows a distinct lithium ion intercalation plateau in the charge–discharge process. The existence of lithium ion intercalation plateau for irregular HC greatly affects the electrochemical behavior of HC negative electrode and AC positive electrode. The effect of working potential range on the electrochemical performance of LIC-SH and LIC-IH is investigated by the galvanostatic chargingdischarging, electrochemical impedance tests and cycle performance testing. The charge–discharge potential range of the irregular HC negative electrode is lower than the spherical HC electrode due to the existence of lithium ion intercalation plateau, which is conducive to the sufficient utilization of the AC positive electrode. The working potential range of LIC should be controlled to realize the optimization of electrochemical performance of LIC. LIC-IH at the working potential range of 2.0-4.0 V exhibits the optimal electrochemical performance, high energy density up to 85.7 Wh kg1 and power density as high as 7.6 kW kg1 (based on active material mass of two electrodes), excellent capacity retention about 96.0% after 5000 cycles.