Redox-Active Covalent Organic Frameworks And Porous Polymers For Electrochemical Energy Storage

Abstract

Covalent organic frameworks (COFs) are an emerging class of crystalline two- or threedimensional polymers, discovered in 2005, with the ability to reliably incorporate functionality within high surface area scaffolds. Early COF literature primarily focused on structural elucidation of boron-based systems and typically alluded to a myriad of applications where the structural precision offered by COFs would be useful. However, these early systems suffered from hydrolytic and oxidative instability which precluded their use in applications. This dissertation describes a recent trend in COFs away from boron-based systems to more inherently robust nitrogen containing frameworks (Chapter 1). We illustrate this by discussing the development of the first redox-active COF which brought COFs into a new application space, namely electrochemical energy storage (Chapter 2). Initially, the performance of the COF was limited by its isolation as in insoluble powder and low electrical conductivity. However, we have addressed these issue through rational design first by targeting thin films (Chapter 3) and subsequently by examining the performance of a COF / conducting polymer hybrid (Chapter 4). We then applied the same electrochemical reasoning of COFs to a less ordered amorphous porous polymer where we expanded the energy density by controlling the cation of the electrolyte (Chapter 5). This work will serve as a roadmap for the design of future framework materials for electrochemical energy storage. i