Design and synthesis of porous organic frameworks for energy storage applications

Abstract

With the rapidly growth of energy requirements and concerns for environmental issues, organic batteries have been heralded as next-generation green battery owing to their high theoretical capacity with multi-electron reaction, adjustable molecular structure while being eco-friendly and potentially cost efficient. However, the ease of dissolution in electrolyte, intrinsically poor electronic conductivity, and low volumetric energy density greatly restrict their long-term cyclability and rate capability, impeding their widespread usage, especially for practical battery systems. In this sense, new electrode materials with high energy/power density have become a long sought of aim to overcome the limited performances of organic batteries. Considering this, a great number of molecular engineering strategies have been proposed to overcome the above obstacles. In this thesis, I have introduced current energy and environmental systems along with their detail working principles, and outlined several recent advances of porous organic material based energy systems. Afterwards, the three synthetic strategies to develop high performance porous organic materials were successively dealt with

1) Top-down approach, 2) Bottom-up approach, 3) crystalline-controlled approach. The redox chemistry and electrochemical kinetics of developed materials were in-depth investigated by using operando and ex situ techniques as well as theoretical calculations. In last, some critical challenges and future perspectives of organic energy materials for practical systems have been addressed in more depth. I believe this thesis will offer fundamental and useful guidance not only for the rational design of porous organic materials but also for practical environmental and energy systems applicable in the foreseeable future.