Yoon Seok Jung

Presentation Enabling Li metal and Si electrodes for All-Solid-State Pouch Cells

Owing to their potential for enhanced safety and energy density compared with conventional lithium-ion batteries, all-solid-state batteries (ASSBs) have been intensively developed and are now at the forefront of commercialization. In particular, highly conductive and mechanically sinterable sulfide solid electrolytes (SEs) are key enablers for the scalable production of practical ASSBs. In parallel, halide SEs, which offer similarly favorable mechanical properties along with enhanced electrochemical oxidative stability, have emerged as promising candidates for use in cathodes. To surpass the energy density of current LIBs, ASSBs must incorporate high-voltage cathode chemistries and/or high-capacity electrodes, particularly Li metal (including ‘Li-reservoir free’ or anodeless systems) or Si anodes. However, integrating these anodes into ASSBs remains highly challenging. For Li metal anodes, not only severe reactivity but also their tendency for penetrating growth has long been a critical hurdle. This issue arises not only during cell operation but also during fabrication. For Si anodes, their intrinsically poor transport characteristics and severe volume changes lead to poor reversibility, particularly under practically relevant low-pressure conditions. In this presentation, we will discuss our recent strategies for stabilizing Li metal and Si anodes in ASSBs. In particular, we reveal the degradation modes of Li-metal ASSBs during high-pressure fabrication and highlight a mechanically reinforced SE membrane strategy that prevents detrimental Li penetration, ultimately enabling bipolar-stacked ASSBs (Figure 1). Furthermore, we discuss an approach to facilitating conducting pathways within Si composite electrodes for low-pressure operation. Finally, we propose an alternative interfacial engineering strategy for anodeless ASSBs.