INS5-0653
Extending NDI-Based n-Type Electronic Polymers to Battery Cathodes through n-Doping Chemistry
When and Where
Sep 30, 2026
11:35 - 11:50
Presenter(s)
Wonho Lee (Kumoh National Institute of Technology)
Co-Author(s)
Abstract
Naphthalenediimide (NDI)-based conjugated polymers are representative n-type semiconducting polymers in organic electronics, where their low-lying LUMO levels and reversible n-doping/dedoping behavior enable efficient electron transport. Here, we translate this electronic functionality into electrochemical charge storage by developing NDI-based polymers as organic cathodes for lithium-ion batteries. The prototypical polymer P(NDI2OD-T2), known as N2200, provides excellent cycling stability through its conjugated backbone and dissolution-resistant polymer structure, but its practical capacity is limited by electrochemically inactive alkyl side chains and donor units. To overcome this limitation, we molecularly engineered the NDI polymer by shortening the side chains and simplifying the donor linker, yielding P(NDI2BO-V). This design increases the specific capacity from 56.9 to 86.0 mAh/g while preserving stable cycling performance. Mechanistic analyses reveal that linker engineering not only tunes LUMO energy levels and operating voltage but also changes the n-doping pathway from a one-step two-electron process to a stepwise single-electron process. This structural change further creates a trade-off between electronic mobility and Li+ diffusivity, emphasizing the importance of molecular packing. Overall, this work highlights NDI polymers as a versatile platform connecting organic electronics, redox-active polymer design, sustainable cathode chemistry, and rechargeable energy-storage materials beyond conventional device applications through rational molecular engineering strategies.
