Hybrid lithium-ion battery-capacitor energy storage device with hybrid composite cathode based on activated carbon / LiNi_0.5Co_0.2Mn_0.3O₂

As the energy demand around the world grows so does the need for devices that can be tailored to fit a specific design's parameters. Often, this can lead to a device that falls between the two traditional groups of lithium-ion battery (LIB) and lithium-ion capacitors (LIC). An emerging way to bring these devices together is using composite cathodes. Composite cathodes combine a capacitor material with battery material and have shown to be able to enhance life cycle energy and power performance compared to their non-composite counterparts. We report here on a hybrid LIC consisting of a Lithium nickel cobalt manganese oxide (NMC)/activated carbon (AC) composite cathode in combination with an ultra-thin lithium film (u-Li) pre-loaded on a hard carbon anode. Additionally, we show that by utilizing three design approaches: dry composite electrode fabrication method, cathode to anode capacity ratio design, and pre-lithiation method using u-Li, we can demonstrate an energy storage device with excellent cycle life, and that can be tailored by composite ratios within the cathode to fit different applications. Shown here is an in-depth look at various composite material ratios, pre-lithiation calculations, and hybrid lithium-ion battery-capacitor energy storage device creation based on targeting essential energy-power performance characteristics.