Contents lists available at ScienceDirect Solid State Ionics journal homepage: www.elsevier.com/locate/ssi A facile approach to investigate the charge storage mechanism of MOF/ PANI based supercapattery devices Muhammad Zahir Iqbal b, ⁎ , Mian Muhammad Faisal b, ⁎ , Syeda Ramsha Ali Meshal Alzaid a a Physics Department, College of Science, Jouf University, Al-Jouf, Sakaka P.O. Box 2014, Saudi Arabia b Nanotechnology Research laboratory, Faculty of Engineering Sciences, GIK Institute of Engineering Sciences and Technology, 23640, KP, Pakistan ARTICLEINFO Keywords: Asymmetric supercapacitor Supercapattery MOF PANI Capacitive/difusive ABSTRACT Supercapattery a combo of supercapacitors and batteries that embraces the features of both technologies in a single assembly. To justify this claim, a systematic approach has been employed to evaluate the performance of the combo device. In this regard a novel material is synthesized via hydrothermal technique and later on physically blended with polyaniline (PANI) to boost the performance of the pristine material. This matrix ma- terial expresses excellent performance by showing a specifc capacity of 154 C/g in cyclic voltammetry (CV) and 162 C/g in galvanostatic charge discharge (GCD). Furthermore, this electrode material was sandwiched with activated carbon to fabricate the supercapattery device. The supercapattery performance was evaluated through CV, GCD, and electrochemical impedance spectroscopy (EIS). This device indicates a specifc capacity of 104 C/ g, 23.11 Wh/kg specifc energy, and 6400 W/kg of specifc power. Finally, a theoretical Dunn's model was applied to eliminate the faradaic and non-faradaic contribution of the real device. It was evidenced that the device storage was not purely faradaic (difusive) neither non-faradaic (capacitive), but it is the combination of both contribution. The capacitive and difusive contribution was found dependent on the scan rate and was due to the time ofered to the ions for interaction with the electrode material. Our study ofers the development of novel metal-organic framework/polyaniline-based electrode material for supercapattery devices as well as a unique route to probe the performance of the supercapattery. 1. Introduction To fulfll the energy demand of this world, energy storage plays an important role along with overcoming the issue of extinction of fossil fuels. The reason behind the rapid growth of batteries and super- capacitors technology is this energy-dependent world [1–5]. Although batteries have many types, but each owns high specifc energy either gravimetric or volumetric when compared with other energy devices, making it apposite for various electrical applications. However, prac- tical usage is limited in many circumstances, due to the thermal in- stability problem and the small values of specifc power by battery technology [6–8]. A short circuit is another big concern in using battery technology because of the leakage of liquid electrolytes, fammability, dendrites formation, and volatility [9]. Besides, supercapacitors are attaining major attention among energy storage technology as it owns longer lifetime, high power densities, quick charging property, and excellent reversibility processes [10–14]. Supercapacitors family is ca- tegorized into the following parts such as electric double layer capa- citors (EDLCs) and pseudocapacitors according to their charge storage mechanism [15]. Although supercapacitors do not own high energy densities in comparison to batteries still researchers are keen to explore various materials as an electrode for supercapacitor focusing mainly on EDLC. As of now, it is clear that both the technologies along with their advantages do have some limitations which depicts that individually none of them can fulfll the huge energy demand of this world. Keeping this situation in mind, researchers found a novel way, of merging the two technologies, leading towards the development of electrochemical energy storage (EES) technologies. This novel route opens ways to various new hybrid devices, but the best among them to get major at- tention is supercapattery device. Supercapattery, the technology giving the high-specifc energy of the battery and the high-specifc power demand simultaneously from EDLC (supercapacitor). Practically seeking the electrodes of the two technologies are merged which is the carbonaceous material of EDLC as one electrode of the device while the battery graded material as another electrode makes up a novel super- capattery device. This combination of two technologies has the char- acteristics of rechargeable battery and also the features of super- capacitors including the long lifetime and the high specifc energy as https://doi.org/10.1016/j.ssi.2020.115411 Received 6 May 2020; Received in revised form 6 June 2020; Accepted 2 July 2020 ⁎ Corresponding authors. E-mail addresses: zahir.upc@gmail.com (M.Z. Iqbal), mianmuhfaisal@gmail.com (M.M. Faisal). Solid State Ionics 354 (2020) 115411 0167-2738/ © 2020 Elsevier B.V. All rights reserved. T