Designing High Performance Organic Batteries

Abstract

Conspectus Redox active organic and polymeric materials have witnessed the rapid development and commercialization of lithium-ion batteries (LIBs) over the last century and the increasing interest in developing various alternatives to LIBs in the past 30 years. As a kind of potential alternative, organic and polymeric materials have the advantages of flexibility, tunable performance through molecular design, potentially high specific capacity, vast natural resources, and recyclability. However, until now, only a handful inorganic materials have been adopted as electrodes in commercialized LIBs. Although the development of carbonyl-based materials revived 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 many challenges. For example, it is still essential to enhance the theoretical and experimental capacities of organic materials. Moreover, typically, organic materials suffer 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 high voltage output and low cost, are also crucial for organic batteries. Therefore, insights into 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 efforts to develop high performance organic batteries with various strategies from the aspects of molecular design and the manipulation of other components. Inspired by the experience in organic electronics, we proposed that the extension of the π-conjugated system is helpful for stabilizing the +1/–1 charge/discharge states, improving the charge transport, and facilitating the layered packing (good for ionic diffusion) and hence would benefit the rate capability and cyclability. The π–d conjugation can effectively improve the electrical conductivity and provide stable and fast ionic storage, which enriches the materials for high-performance batteries and further deepens the understanding of conjugated coordination polymers (CCPs). Different from inorganic materials, organic materials are composed of molecules (either small molecules, macromolecules, or polymeric molecules) with weak intermolecular interactions. Therefore, the manipulation of active molecules or additives (conductive additives, binders, and other special additives) through control of intermolecular interactions is crucial for enhancing the electroc...

Organic Negative Electrode Materials for Metal‐Ion and Molecular‐Ion Batteries: Progress and Challenges from a Molecular Engineering Perspective

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Regulating the Solvation Sheath of Li Ions by Using Hydrogen Bonds for Highly Stable Lithium–Metal Anodes

“…The rising of energy demand is calling for alternatives of traditional lithium‐ion batteries (LIBs) [1–10] . In this regard, the lithium‐metal batteries (LMBs) provide a new possibility for high energy density systems [8, 11–18] by using Li metal as anodes, due to its ultrahigh theoretical capacity (3860 mAh g −1 ) and low electrochemical potential (−3.04 V vs. the standard hydrogen electrode).…”

Diradicals or Zwitterions: The Chemical States of m -Benzoquinone and Structural Variation after Storage of Li Ions

“…[1][2][3][4][5][6][7] Hence, various organic materials have been reported as electrodes for batteries. [8][9][10][11][12] Among them, carbonyl-based materials are of the most significance because of the high capacity and stable charge/discharge voltage, which stimulated the reviving of organic batteries. However, the reported carbonyl materials are mainly based on oor pbenzoquinones, o-imides or p-carboxylates.…”