Transformation of Environmentally Threatening Prosopis Juliflora into Tubular Carbon As Excellent Electrodes for Li-Ion Capacitors

Abstract

Sustainable renewable energy generation from sources that would otherwise be environmental pollutants and transportation of such energies for the desired applications would lead to significant global social and economic development. The commercially available energy storage devices such as supercapacitors and Li-ion batteries (LIB) energy and power densities are significantly lower than those necessary for applications in zero-emission transportation such as electric vehicles (EV, >150 Wh kg–1) & plug-in hybrid electric vehicles (P-HEV, 57 to 97 Wh kg–1).(1) The Li-ion hybrid electrochemical capacitor (Li-HEC) constructed with Li-ion insertion as anode and double-layer forming component as positive electrode, which provides the desired energy and power densities, respectively. (2, 3) Here, the environmentally threatening and invasive weed of Prosopis juliflora is converted as electrode materials. Prior to testing the P. juliflora AC as an electrode for charge storage, we have carried out a systematic study on the preparation of AC from P. juliflora . Firstly, the influence of the pore forming agent, i.e., KOH, and its capacitive behavior has been evaluated in symmetric configuration. Subsequently, the energy density has been increased by introducing a homemade insertion type electrode Li4Ti5O12 with P. julifloraderived AC as the supercapacitor component in a Li-HEC assembly. In addition, extensive physico-chemical properties, including XRD, BET surface area, Raman analysis, XPS, and SEM studies, were conducted and are described in detail.