Monolithic 100% Silicon Wafer Anode for All-Solid-State Batteries Achieving High Areal Capacity at Room Temperature

Abstract

Silicon is an attractive anode material for all-solid-state batteries (ASSBs) because it has a high energy density and is safer than metallic lithium. Conventional silicon powder composite electrodes have significant internal voids and detrimental interfaces that suppress the lithium transport and lifetime. Here, we demonstrate that surface-treated thin silicon wafers could serve as monolithic additive-free, electrolyte-free, and void-free electrodes that can achieve high areal capacity at room temperature (∼25 °C). A dense solid electrolyte interface could effectively suppress the cracks and pulverization found in the liquid electrolyte. We demonstrated that the grooved <110> wafer exhibited reversible (de)lithiation owing to fast lithium distribution along the <110> thickness direction. The surface groove could effectively penetrate the electrolyte layer, yielding a stable interfacial resistance and homogeneous alloying/dealloying processes during cycling. Our silicon wafer electrode achieved an areal capacity of 10 mAh cm–2 at room temperature, which can be improved by further optimization.

Recent advances in all-solid-state batteries for commercialization

“…174,175 Additionally, research on low-reactivity silicon anodes is in progress, with studies reporting on their exceptional performance using additive-free, electrolyte-free, and void-free silicon wafer electrodes. 176…”

Advancing sustainable end-of-life strategies for photovoltaic modules with silicon reclamation for lithium-ion battery anodes

“…The silicon wafer can also be reused in all-solid-state batteries (ASSBs). Na et al 73 reported an interesting study where grooved Si wafer presented better performance as an anode in ASSBs, paving a new way for next-generation high-energy ASSBs. Inspired by this work, waste solar cells have the potential to be directly reused in ASSBs with or without a simple surface purification process, avoiding the morphological modification process in the proposed upcycling strategy.…”

“…77 As of August 2021, the average spot market price for silicon metal was nearly 50% higher than the annual average price in 2020. 73 Generally, the strategy of upcycling silicon from solar panels to Si-based anodes enriches the secondary use scenarios of silicon, making the solar panel and LIB supply chains more intertwined. Therefore, this strategy can effectively enhance the flexibility and efficiency of silicon supply chains.…”

Si Nanowires: From Model System to Practical Li-Ion Anode Material and Beyond

“…Si NW use has mostly been examined in Li-ion/Li-metal batteries; however, it has also gained some interest in solid-state batteries (SSBs) as well as alternative alkali-ion batteries (i.e., Na-ion). Recently, various types of Si, such as monolithic, microparticles, , nanoparticles, amorphous films, , and columnar a-Si, have been used with different solid electrolytes (SE), with demonstrations of exceptional performance even with micrometer-sized Si particles. However, the use of nanostructured Si and especially 1D Si morphologies , in SSB is still in its infancy, and a complete mechanistic understanding of the interfacial reactions (especially SEI formation) is required.…”