Recent advances in conjugated polymer energy storage

Abstract

This review covers recent advances in conjugated polymers and their application in energy storage. Conjugated polymers are promising cost-effective, lightweight, and flexible electrode materials. The operating principles of conjugated polymers are presented within the framework of their potential for energy storage. Special focus is given to polyaniline electrodes. Recent advances are reviewed including new methods of synthesis, nanostructuring, and assembly. Also, covered are applications that take full advantage of the mechanical properties of conjugated polymers and future applications of these novel materials.

Discharge Characteristics of Lithium Battery Electrodes with a Semiconducting Polymer Studied by Continuum Modeling and Experiment

“…During discharge of the cathode, electrons flow to the active particles through the conducting carbon network while the electrolyte in the pores conveys the lithium ions necessary to complete the redox reaction. An example of such a reaction is Li + + 1e − + FePO 4 ↔ LiFePO 4 [1] The reverse reaction above occurs during charge. The resistance to electron transport is independent of time and electrode potential in conventional batteries as the carbon particles form a simple ohmic conducting network.…”

“…1 The main difference between such electrodes and conventional battery electrodes is that the polymer is a semiconductor wherein electronic conductivity is a function of electrode potential. In addition to oxidation and reduction of the active particles (Reaction 1), the conducting polymer gets oxidized and reduced.…”

Scalable Synthesis and Multi‐Electron Transfer of Aniline/Fluorene Copolymer for Solution‐Processable Battery Cathodes

“…The low reversible doping levels (0.3-0.5) of most of these CPs, however, have resulted in low capacities that limit their practical use. [2,13,14] Over the past few years, polyaniline has been identified as an ideal electrodes. The synthesis was achieved in a facile and scalable manner.…”

“…[1][2][3][4][5][6] Over the past decades, various kinds of CPs including polyaniline, [7,8] polypyrrole, [9,10] and polythiophene [11,12] have been investigated as cathode materials for lithium ion batteries. The low reversible doping levels (0.3-0.5) of most of these CPs, however, have resulted in low capacities that limit their practical use.…”

“…[15,16] However, the experimental capacities of polyaniline-based electrodes are often in the range of 100-147 mAh g −1 because of issues with stability. [2,16] Another consideration is that of processability, where many CPs are intractable and difficult to process into application-relevant forms, [17,18] with many forms being achievable only by electropolymerization. [19] Therefore, the development of solution-processable CPs with high doping levels presents a great challenge and requires a comprehensive molecular engineering approach with rational design.…”