All-polymer battery system based on polypyrrole (PPy)/para (toluene sulfonic acid) (pTS) and polypyrrole (PPy)/indigo carmine (IC) free standing films

In this study, we introduce a novel all-polymer battery system based on conducting polymer (polypyrrole, PPy) doped with dopants of para (toluene sulfonic acid) (pTS) and indigo carmine (IC), respectively. The performance of the systems consisting of polypyrrole-para (toluene sulfonic acid) (PPy-pTS) as cathode and polypyrrole-indigo carmine (PPy-IC) as anode in conjunction with either a polymer based electrolyte or a commercial organic electrolyte of 1M LiPF6 in a 50:50 (v/v) mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC) was evaluated. In the system, all the free-standing PPy-pTS and PPy-IC films were directly used without needing any metal substrate support to hold the electro active material. Electrochemical measurements demonstrated that the PPy-pTS/PPy-IC (commercial electrolyte) system exhibited a reversible discharge capacity of 36 mAh g(-1) at 0.05 mA cm(-2) after 50 cycles, is 92% of the initial discharge capacity. In the case of PPy-pTS/PPy-IC (polymer electrolyte), the reversible discharge capacity after 50 cycles was 16 mAh g(-1), 76% of the intial discharge capacity. This work deals with the fabrication of a novel all polymer battery system, with significant advantages in terms of capacity and reasonable stability. This may lead to a future generation of all polymer batteries that are suitable for implanted medical devices used in biological and biomedical systems. (c) 2012 Elsevier Ltd. All rights reserved.