得到编辑部邀请，课题组在Acc.Chem.Res.上撰文，总结课题组近年在有机电池相关领域取得的进展。祝贺陈远！
Y. Chen, C. Wang*, Designing High Performance Organic Batteries. Acc. Chem. Res. 2020, DOI: 10.1021/acs.accounts.0c00465.
CONSPECTUS: Redox active organic/polymeric materials have witnessed the rapid development and commercialization of lithium-ion batteries (LIBs) since last century and the increasing interest of developing various alternatives of LIBs in the past 30 years. As a kind of potential alternatives, organic/polymeric materials have the advantages of flexibility, tunable performance through molecular design, potentially high specific capacity, vast natural resources and recyclability. However, till now, only handful inorganic materials have been adopted as electrodes in the commercialized LIBs. Although the development of carbonyl-based materials revived the organic batteries and stimulated plentiful organic materials for batteries in the past 10 years due to their high theoretical capacities and long-term cycleabilities compared with their pioneers (e.g. conducting polymers), organic batteries are still facing a lot of challenges. For example, it is still essential to enhance the theoretical and experimental capacities of organic materials. Moreover, typically, organic materials are suffering relatively low conductivity, which limits their rate capability. In addition, many organic materials, especially small molecules, show poor cycling stability because of their dissolution in organic electrolytes. Other requirements such as the high voltage output and low cost etc. are also crucial for organic batteries. Therefore, insightful fundamentals (e.g. intramolecular and intermolecular interactions) for a deep understanding of organic batteries and constructive strategies ranging from material design to manipulation of other components (e.g. conductive additives, binders, electrolytes and separators through controlling the intramolecular and intermolecular interactions and manipulating the ionic transport), are of great significance to boost the performance of organic batteries.
In this Account, we give an overview of our attempts toward high performance organic batteries with various strategies from the aspects of molecular design and the manipulation of other components. Inspired from the experience in organic electronics, we proposed that the extension of π-conjugated system is helpful for stabilizing the +1/-1 charged/discharged states, improving the charge transport, facilitating the layered packing (good for ionic diffusion) and hence would benefit the rate capability and cycleability (section 2.1). The π-d conjugation can effectively improve the electrical conductivity and realize stable and fast ionic storage, which enriches the materials for high-performance batteries and further deepens the understanding of conjugated coordination polymers (CCPs, section 2.2). Different from inorganic materials, organic materials are composed of molecules (either small, macro- or polymeric molecules) with weak intermolecular interactions. Therefore, the manipulation of active molecules and/or additives (conductive additives, binders and other special additives) through control of intermolecular interactions is crucial for enhancing the electrochemical performance of organic batteries (section 2.3 and section 3). Regard to the possible dissolution of active materials, the modification of separators through adding selectively permeable membranes as ionic sieves is the most efficient and universal strategy to mitigate the shuttle of dissolved molecules but allow the pass of smaller sized cations, and hence is able to enhance the cycleability (section 4). On the basis of these findings, the challenges and several future trends of organic batteries are discussed. This account provides a summary of our recent progress, understanding of the fundamentals for high performance organic batteries, insight into the intramolecular/intermolecular interactions and prospect of future development of organic materials for next-generation rechargeable batteries.
