“…Among the secondary batteries, lithium-ion batteries (LIBs) offer practically high specific energy (150–200 W h kg −1 ) and coulombic efficiency but suffer from limited specific power and cycle life. 5,6 On the other hand, supercaps are considered power devices, capable of fast charge/discharge with exceedingly high cycle life. 7 Due to instant charge/discharge, supercaps find their extensive use where a power surge is demanded.…”