Dynamic volume compensation realizing Ah-level all-solid-state silicon-sulfur batteries

Abstract

State-of-the-art lithium-ion batteries incorporating silicon negative electrodes face significant challenges due to the volume fluctuations that occurs during cycling, leading to enormous internal stress and eventual battery failure. Notably, existing research predominantly focuses on material-level solutions, with limited exploration of effective cell design strategies. Herein, we present a systematic implementation of a Stress-Neutralized Si-S full cell design that leverages the natural volume change dynamics of silicon and sulfur electrodes. Our approach goes beyond inherent stress compensation by employing a dynamic volume compensation strategy. This strategy involves real-time stress monitoring and precise structural optimization to achieve full utilization of the active mass (100%) and to mitigate the residual stresses and heterogeneity that naturally arise during cycling. A quantitative analysis proved the effectiveness of this approach, showcasing high specific energy (525 Wh kg⁻¹) based on total battery mass, long cycling stability (500 cycles), large areal current density (25.12 mA cm⁻²), and high capacity (1.24 Ah) in Si-S system. This approach systematically enhances the naturally occurring stress-compensation phenomenon, addressing the residual stresses and optimizing electrode behavior for high-performance solid-state batteries.