Pre-lithiation design and lithium ion intercalation plateaus utilization of mesocarbon microbeads anode for lithium-ion capacitors

Abstract

ABSTRACT Lithium-ion capacitors (LICs) are assembled with activated carbon (AC) cathode and pre-lithiated mesocarbon microbeads (MCMB) anode. For ensuring the electrochemical performance of LIC, the pre-lithiation capacity of MCMB anode is designed to make the anode at the two lithium ion intercalation plateaus. The utilization of the two plateaus greatly affects the charge-discharge process and behavior at different working potential ranges of LIC, which achieves the regulation of the electrochemical performance. LIC150 using the first plateau of MCMB anode exhibits higher power density and superior cycle performance, and LIC300 using the second plateau of MCMB anode shows higher energy density. The two plateaus utilization of the MCMB anode can be further increased by improving the working potential range. LIC150 and LIC300 display the optimal electrochemical performance at the working potential range of 2.0-4.0 V. LIC150 exhibits high power density of 6.3 kW kg−1 and the energy density up to 62.9 Wh kg−1, capacity retention of 93.4% after 1000 cycles. Besides, the energy density of LIC300 is up to 92.3 Wh kg−1, the power density as high as 5.5 kW kg−1 and excellent capacity retention of 97.0% after 1000 cycles.