Harnessing cheese shell waste as a sustainable binder for enhanced cycle stability in lithium‑sulfur batteries

Abstract

The development of sustainable materials for lithium sulfur (Li–S) batteries is essential to advancing next-generation energy storage. This study introduces recycled cheese shell (RCS), a paraffin wax waste product, as a cost-effective and environmentally friendly binder for Li–S batteries. Compared to standard binders (STD), such as polyvinylidene fluoride (PVDF), the RCS binder enhances sulfur retention and structural stability, promoting higher electrode compaction and better ionic diffusion. RCS-based Li–S cells deliver an initial specific capacity close to 1000 mAh g-1 and exhibit remarkable cycling stability. After 1000 cycles at 0.3C, the capacity loss per cycle is only 0.59 mAh g-1 during the last 100 cycles. At 1C, RCS-based electrodes retain 54 % of their initial capacity after 1000 cycles, with a capacity fade of just 0.22 mAh g-1 per cycle. Additionally, kinetic studies indicate that RCS-based electrodes exhibit faster charge transfer and reduced polarization. Morphological and mechanical studies (SEM, tensile stress and micro-CT) confirm a more compact structure and enhanced particle interconnectivity in RCS-based electrodes. These results highlight the effectiveness of RCS in mitigating degradation mechanisms in Li–S batteries and demonstrate its strong potential as a sustainable binder alternative.