However, because of the low rate of Faradaic process to transfer lithium ions (Li+), the LIB has the defects of poor power performance and cycle performance, which can be improved by adding capacitor material to the cathode, and the resulting hybrid device is also known as a lithium-ion battery capacitor (LIBC).
Lithium-ion capacitors (LICs) consist of a capacitor-type cathode and a lithium-ion battery-type anode, incorporating the merits of both components. Well-known for their high energy density, superior power density, prolonged cycle life, and commendable safety attributes, LICs have attracted enormous interest in recent years.
At present, the most commonly used electrochemical energy storage device is the lithium-ion battery (LIB). An LIB stores/releases energy by a reversible lithium-ions (Li +) intercalation/deintercalation process on the cathode and anode through Faraday reaction, which has the advantage of high energy density.
Schroeder, M.; Winter, M.; Passerini, S.; Balducci, A. On the cycling stability of lithium-ion capacitors containing soft carbon as anodic material. J. Power Sources 2013, 238, 388–394.
In addition, the electrochemical performance of LIBs can be improved by adding capacitor material to the cathode material, and the resulting hybrid device is also commonly referred to as an X-based lithium-ion battery capacitor (LIBC), in which X is the battery material in the composite cathode (X can be LCO, LMO, LFP or NCM).
Capacitor Material in Cathode As mentioned above, AC is the most widely used capacitor material in the composite cathode of LIBCs due to its porous structure, large specific surface area, and good electronic conductivity.