Binder engineering unlocks stable sulfurized polyacrylonitrile electrodes for Li-ion-sulfur cells with the layered LiNi1/3Mn1/3Co1/3O2 cathode

Abstract

Li–sulfur (Li–S) batteries are considered highly promising next-generation energy storage systems because of their exceptionally high theoretical energy density (2500–2600 Wh kg⁻¹). However, their practical application is significantly limited by Li-dendrite formation, parasitic side reactions at the Li-metal anode, and the inherent instability of sulfur cathodes. Sulfurized polyacrylonitrile (SPAN) has gained considerable attention as a sulfur host due to its polysulfide-free redox mechanism, which effectively mitigates the shuttle effect. In this study, the electrochemical performance of SPAN electrodes is systematically enhanced by examining the impact of various binders in a conventional electrolyte (1 M LiPF₆ in EC/DEC with 5 wt/vol% LiBOB) using Li-metal configuration. Amongst all the binders studied, the water-based polyacrylic acid (PAA) binder demonstrates the best performance, delivering a high initial specific capacity of 1484 mAh g⁻¹ and achieving 95% capacity retention after 300 cycles. Moreover, a full-cell configuration is assembled by coupling the optimized SPAN electrode with the commercial layered LiNi_1/3Mn_1/3Co_1/3O₂ (NMC111) cathode. The assembled full cell provides an initial capacity of 1155 mAh g⁻¹ and maintains 88% of its capacity after 100 cycles at a current density of 0.5 A g⁻¹ under ambient conditions. Overall, this work demonstrates that binder and electrolyte engineering is an effective approach to fully exploit the potential of SPAN electrodes for practical high-energy Li-based batteries and it explores the possibility of using SPAN as an anode in Li ion batteries.