8 ISSN 1023-1935, Russian Journal of Electrochemistry, 2017, Vol. 53, No. 1, pp. 8–15. © Pleiades Publishing, Ltd., 2017. Published in Russian in Elektrokhimiya, 2017, Vol. 53, No. 1, pp. 11–20. Quinone Based Conducting Redox Polymers for Electrical Energy Storage 1 R. Emanuelsson, C. Karlsson, H. Huang, C. Kosgei, M. Strømme, and M. Sjödin* Nanotechnology and Functional Materials, Department of Engineering Sciences, The Ångström Laboratory, Uppsala University, Box 534, SE-751 21 Uppsala, Sweden *e-mail: martin.sjodin@angstrom.uu.se Received March 3, 2016 Abstract—Conducting redox polymers (CRPs) constitute a promising class of materials for the development of organic matter based batteries with the potential to overcome the main limitations connected to this type of rechargeable battery systems including low conductivity and dissolution problems. In this report we show that the potential of quinones can be effectively tuned into the conducting region of polypyrrole (PPy), both in water based solutions and in acetonitrile, which is a prerequisite for profitable combination of the two units. We also present a device where both anode and cathode are made from PPy substituted with different quinone pendant groups and where good rate performance is achieved without any conductivity additives thus provid- ing support for the hypothesized synergetic effect of a conducting polymer backbone and a covalently attached redox active pendant group. This device constitutes, to the best of our knowledge, the first all-CRP based battery reported to date. Keywords: conducting redox polymers, secondary batteries, quinone, proton coupled redox reactions, pyri- dinium electrolytes DOI: 10.1134/S1023193517010050 INTRODUCTION Powered by the increasing need for electrochemi- cal energy storage as a result of the transition towards intermittent renewable energy sources, electrification of the transport sector as well as the increased demand for portable electronics, the search for alternative materials that could reversibly store electrical energy has dramatically intensified. Concerns regarding the sustainability, material supply and cost of the domi- nating secondary battery technology, lithium ion bat- teries (LIBs), have also motivated researchers to develop active battery materials from organic matter that could be produced from biomass and be recycled by economically feasible and environmentally benign means [1–8]. One type of organic electrode materials that has recently gained increased attention is con- ducting redox polymers (CRPs), i.e. polymers with a conducting polymer (CP) backbone with redox active pendant groups covalently attached to the CP back- bone [9–17]. In the ideal case the CP backbone serves to provide electronic conduction through the material as well as to decrease the solubility of the active mate- rial, that has been identified as a cause of capacity fad- ing in organic matter based electrode materials [18]. The pendant group, on the other hand, serves as capacity carrying component and the charge storage capacity, the potential and the charge-discharge pro- file is given by the choice of pendant group. As CPs are conducting only in their doped states [19–24], i.e. when they are charged either oxidatively or reduc- tively, the pedant group redox potential must fall within the conducting region of the CP in order to benefit from the CP conductivity. Redox matching of the pendant group and the CP is thus crucial for suc- cessful design of a CRP battery material. Most organic materials that have been tested as active battery mate- rials, however, fall within the non-conducting region of the most common CPs [25]. For instance quinone- type materials, which have attained significant atten- tion in the development of organic matter based bat- tery materials, have potentials in the region –1.75 to ‒0.5 V vs. ferrocene (Fc) in common battery electro- lytes, [25] a potential region where the most common CPs are in their neutral, insulating state [21]. In this report we investigate how the redox potential of qui- nones can be tuned by the choice of electrolyte system. And we show that, under the right conditions, the qui- none redox potential shows an excellent redox match with the conducting region of polypyrrole (PPy) both in aqueous and non-aqueous media. We also present two quinone based CRPs with a PPy backbone where the quinone potentials of the two polymers are differ- ent due to the choice of substituents on the quinone moiety, and we present an all-CRP battery based on these CRPs. 1 The article was translated by the authors.