Iterative design of polymer fabric cathode for metal-ion batteries

Abstract

Organic electrode materials (OEMs) have attracted significant attention for use in aqueous zinc-ion batteries (AZIBs) because of their abundant resources and flexible designability. However, the development of high-performance OEMs is strongly hindered by their high solubility, poor conductivity, sluggish ion diffusion kinetics, and difficult coordination toward Zn²⁺. Herein, inspired by fabric crafts, we have designed a robust polymer fabric through the iterative evolution of the building blocks from point to line and plane. The evolution from point to line could not only improve the structural stability and electrical conductivity but also adjust the active site arrangement to enable the storage of Zn²⁺. In addition to further boosting the aforementioned properties, the evolution from line to plane could also facilitate the construction of noninterference channels for ion migration. Accordingly, the poly(1,4,5,8-naphthalenetetracarboxylic dianhydride/2,3,5,6-tetraaminocyclohexa-2,5-diene-1,4-dione) (PNT) polymer fabric has the most enhanced structural stability, optimized active site arrangement, improved electrical conductivity, and suitable ion channels, resulting in a record-high capacity retention of 96% at a high mass loading of 56.9 mg cm⁻² and a stable cycle life of more than 20,000 cycles at 150 C (1 C=200  mA g⁻¹) in AZIBs. In addition, PNT exhibits universality for a wide range of ions in organic electrolyte systems, such as Li/Na/K-ion batteries. Our iterative design of polymer fabric cathode has laid the foundation for the development of advanced OEMs to promote the performance of metal-ion batteries.