Development of a High-Energy-Density Lithiated Silicon-Sulfur Full Cell with Enhanced Stability and Longevity

Silicon-sulfur (Si-S) batteries represent a promising energy storage solution due to their high theoretical energy density. However, practical applications have been hindered by substantial volume expansion of silicon and the dissolution of sulfur species. Here, we combine a triazine-based graphdiyne-coated silicon (TzG@Si) anode and a sulfurized polyacrylonitrile (S@PAN) cathode into a cell that uniquely mitigates the volume expansion of silicon and prevents sulfur migration. Notably, the integration of TzG@Si and S@PAN results in the formation of a stable, LiF-rich solid-electrolyte interphase (SEI) on both electrodes, significantly enhancing the cycling stability. The optimized cell exhibits an energy density of 414.3 Wh kg-1 based on electrodes’ mass (Si anode and S@PAN cathode), with a capacity retention exceeding 80% after 400 cycles. Moreover, we explore the lithiation mechanisms within the S@PAN cathode, revealing that controlled voltage windows can further improve performance by preventing deep discharge. Our findings suggest that by engineering the electrodes, this Si-S battery system can achieve long cycle life and high energy density. This work not only advances the understanding of Si-S battery chemistry but also highlights the importance of synergistic electrode and electrolyte design in developing practical solutions for high-energy-density batteries.