Montmorillonite nanoreactors for synergistic confinement synthesis and ion-conduction in stable sulfurized polyacrylonitrile cathodes

Abstract

Sulfurized polyacrylonitrile (SPAN) is a promising cathode for lithium-sulfur batteries, yet its practical application is hindered by structural degradation under long-term cycling at high rates. Herein, we report a synergistic nanoconfinement strategy using montmorillonite (MMT) lamellae as nanoreactors for the in situ polymerization of acrylonitrile and subsequent sulfurization. This approach not only stabilizes the SPAN structure but also leverages the innate interlayer galleries of MMT as efficient lithium-ion transport channels. The resulting SPAN/MMT cathode delivers exceptional cycling stability with a capacity decay rate of only 0.014% per cycle over 5000 cycles at a high current density of 3 A g⁻¹. This work highlights the potential of nanoconfinement engineering for developing advanced electrode materials.