Investigation of graphene loaded polypyrrole for lithium-ion battery Oladipo Folorunso a,⇑ , Yskandar Hamam a,b , Rotimi Sadiku c , Suprakas Sinha Ray d,e , Gbolahan Joseph Adekoya c a French South African Institute of Technology (F’SATI)/Department of Electrical Engineering, Tshwane University of Technology, Pretoria 0001, South Africa b École Supérieure d’Ingénieurs en Électrotechnique et Électronique, Cité Descartes, 2 Boulevard Blaise Pascal, 93160 Noisy-le-Grand, Paris, France c Institute of NanoEngineering Research (INER)/Department of Chemical, Metallurgy and Material Engineering, Tshwane University of Technology, Pretoria 0001, South Africa d Centre for Nanostructures and Advanced Materials, DSI-CSIR Nanotechnology Innovation Centre, Council for Scientific and Industrial Research, Pretoria 0001, South Africa e Department of Applied Chemistry, University of Johannesburg, Doornfontein, 2028 Johannesburg, South Africa article info Article history: Received 2 November 2019 Received in revised form 16 March 2020 Accepted 20 March 2020 Available online xxxx Keywords: Graphene Polypyrrole Energy storage Density function theory Lithium ion abstract The discredit state of lithium-ion (Ln) battery is as a result of the challenges associated with electrodes, inadequate power and energy densities. For a battery to be classified as suitable for electric vehicle and grid power suppliers, electrodes must be manufactured with the main aim of providing high power and high energy densities. Graphene (Gr) is a thin, single layer of graphite, whose electrical and mechanical properties can be easily re-orientated to obtain diverse applications. The re-orientation of the properties of graphene for electrode application, in this study, is achieved by its addition to a high conducting poly- mer, i.e. polypyrrole (Ppy) in the presence of Ln. This investigation was conducted by using density func- tion theory to predict the power and energy densities of the electrode. The analysis of the investigation revealed that the composite of Gr/Ppy/Ln, is a promising battery electrode, which can deliver the required energy for electric vehicles. Ó 2020 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Sympo- sium on Nanostructured, Nanoengineered and Advanced Materials. 1. Introduction The study and the application of materials, whose sizes are lower than 100 nm is called nanotechnology; these materials are essentially inimitable, due to their chemical, electrical and mechanical properties, such as size, tunneling and surface effects [1]. Graphene is a carbonaceous nanomaterial, which has good electrochemical stability in a redox reaction [2]. The expectation of sustainable green energy and hence, a green world, is promising, if sufficient attention and research can be directed and conducted on graphene-polymer composites and in particular, composites, e.g. graphene/polypyrrole (Gr-Ppy). The vast applications of gra- phene, include manufacturing of high-frequency electronic devices, optoelectronics, spintronics, sensors, biomedical equip- ment, superconductors, solar cells, batteries electrodes, electric cars, aeroplanes, and military equipments [3–7]. The high electrical conductivity and nano-size characteristics, attributed to graphene, make it a multipurpose choice for compositing polymeric materials for diverse applications [8–10]. Polypyrrole, polyaniline, poly(3,4-ethylenedioxythiophene), polyacetylene, MXxene and paraphenylene, belong to the group of polymers that are intrinsically conductive. Among the host of conductive polymers, polypyrrole is the one with the most excel- lent energy storage capability. As reported by Zhang et al. [11], polypyrrole has strong binding energy when composited with gra- phene; this effect is very important to avoid diffusion of ions out of the electrochemical electrodes. When the diffusion of ions is restricted from occurring at the electrode surface, the battery is expected to have better cycling and good performances. Polypyr- role is useful in the manufacturing of sensors, supercapacitors, and light-sensitive devices [3]. Moreover, nanostructured elec- trodes have been characterized with stable cyclability, high power density, high specific capacity, high electrical conductivity and they are mechanically stable. This is because nanomaterials have high surface area and excellent transport energy [12–14]. In addi- tion, by combining the properties of polypyrrole with graphene, a composite that can produce high energy and power density battery electrodes is envisaged. https://doi.org/10.1016/j.matpr.2020.03.522 2214-7853/Ó 2020 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Symposium on Nanostructured, Nanoengineered and Advanced Materials. ⇑ Corresponding author. E-mail address: oladfol2013@gmail.com (O. Folorunso). Materials Today: Proceedings xxx (xxxx) xxx Contents lists available at ScienceDirect Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr Please cite this article as: O. Folorunso, Y. Hamam, R. Sadiku et al., Investigation of graphene loaded polypyrrole for lithium-ion battery, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2020.03.522