Helical Poly(isocyanide anthraquinones)‐Based Cathodes for Long‐Cycling Lithium Metal Batteries

Abstract

AbstractThanks to the unique rigid conformation and designable side‐chain structure, helical polymers are starting to be more widely considered as ideal electrode materials in secondary batteries. In this study, a series of helical poly(isocyanide anthraquinones) (PIC‐AQs), including PIC‐1AQn and PIC‐2AQn, were designed and synthesized via living polymerization using a palladium catalyst (Pd‐II). The polymers feature a helical polyisocyanide main chain and anthraquinone (AQ) pendants, offer high yields (approximately 90%), controlled number‐average molecular weight (Mn), and a low polymer dispersity index (PDI). Attributed to a narrow energy band gap, low unoccupied molecular orbitals, and high spatial freedom of PIC‐2AQ, it exhibits excellent long‐term stability in lithium metal batteries (LMBs), maintaining 141 mAh g−1 after 2000 cycles at 1 A g−1. Additionally, an in situ polymerized poly(ionic liquid) electrolyte was prepared for assembling a PIC‐2AQ all‐solid‐state soft‐pouch battery. And it remained stable under extreme operations like bending or cutting. Such a battery significantly broadens the application scope of organic LMBs and offers great potential for their use in flexible electronic devices.