Lithium ion capacitors (LICs) are receiving extensive attention as a potential energy storage device due to their high capacitance, high rate capability, and long cycle life. Graphite is presently the most common anode material for lithium ion capacitor. This is mainly due to its high lithium storage performance with a theoretical specific capacity of 372 mAh/g. However, to utilize graphite maximum lithium storage properties, the device needs to be charged and discharged at a low current density. At high current density graphite’s storage performance drastically diminish because of large mass transfer resistance. Hence it is critical to develop a low resistance material to facilitate ion and electron transport in the material at high current density. In this study, we demonstrate that Coalesced Carbon Onion (CCO) with a particle size in the range of 10-20 nm is a promising candidate to overcome the rate limitation of battery type anode materials such as natural graphite.<br/>Additionally, several cathode materials were synthesized using the polymer precursor and soft templating approach. Among the synthesized activated carbons, bimodal carbon with distinct micro and mesopores derived from polyfurfuryl alcohol/ phloroglucinol exhibit superior power and energy performance. Here, we show outstanding rate and energy performance of LIC made using bimodal activated carbon derived from polyfurfuryl alcohol/ phloroglucinol as a cathode in conjunction with coalesced carbon onion anode. The fabricated device shows the capability to store energy density of 52 Wh/kg at 7.3 KW/kg. Besides remarkable cyclability with 80% capacitance retention after 21000 cycles when cycles between 2.2V to 4V and discharge time of 25 s was achieved.

Coalesced carbon onion anode: Towards high-rate anode materials for lithium-ion capacitor

2019 Spring National Meeting

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