Fabrication of High Energy Li–Ion Capacitors from Orange Peel Derived Porous Carbon

Abstract

AbstractActivated carbon (AC) with high surface area (1,901 m2 g−1) is synthesized from bio‐waste orange (Citrus sinensis) peel for fabrication of high specific energy lithium ion capacitors (LICs). The composition, structure and electrochemical properties of orange peel derived AC (OP‐AC) are characterized by elemental analyzer, field emission‐scanning electron microscopy, X‐ray diffraction, Raman spectroscopy, X‐ray photoelectron spectroscopy, cyclic voltammogram, charge‐discharge and impedance studies. Fabricated LIC using the high surface area OP‐AC with pre‐lithiated graphite (LiC6) delivered specific energy of ∼106 Wh kg−1. In addition, LIC configuration with Li4Ti5O12 was also fabricated and observed to be capable of delivering the specific energy of ∼35 Wh kg−1. Symmetric configuration of OP‐AC with aqueous and organic solutions was also made for comparison purpose. A systematic improvement from the specific energy of ∼7 to 106 Wh kg−1 is noted from aqueous to LIC assembly. The findings open up the possibility of developing high specific energy LICs from abundant, low‐cost, sustainable biomass waste.