ABSTRACT
The most popular and only commercialized cathode material in Lithium-Ion Supercapacitors (LISC) is activated carbon (AC), which is also the widely used electrode material in traditional electrochemical double-layer capacitors (EDLC). With AC functioning as capacitive cathode, a wide spectrum of anode materials has been paired with AC and formed LISCs with different properties and performances. Good availability of both the cathode and the anode materials, along with improved performance of carbon-based LISCs, has presented a promising future for this system. Compared to EDLC materials, incompetence of operation at high current densities accounts for a major problem for insertion-type cathodes. Conventional layered oxides, spinel oxides, and phosphates are popular candidates for cathode in aqueous LISCs. Utilizing a battery-like cathode and a capacitive anode is a viable approach to constructing a LISC. Further, many of the new cathodes can be applied in aqueous LISCs, which have garnered much interest, especially owing to their safety and cost advantages over organic LISCs.
