Constriction Effect in All-Solid-State Cathodes

作者：Moritz Bohn, Gioele Conforto, Tobias Kutsch, Robin Schuster, H. Gasteiger · 发表于：ECS Meeting Abstracts · 年份：2024 · DOI：10.1149/ma2024-0281064mtgabs

The demand for batteries with high gravimetric and volumetric energy density is driving research towards the development of new battery technologies. All-solid-state batteries (ASSBs) offer the potential to address current challenges faced by liquid electrolyte-based batteries, such as the implementation of Li-metal or fully utilized silicon as an anode material.1 To date, however, there are no commercially available ASSBs with an inorganic solid electrolyte on the market, because of new challenges when using solid electrolytes, such as interfacial stability, solid-solid contact problems, or the ability to operate at low pressures.2 Eckhardt et al.3 recently demonstrated that voids at the interface of a solid electrolyte based separator and a Li-metal anode cause an additional resistance called constriction resistance. This effect occurs when current lines are constricted by bottlenecks (voids) at the interface. In the absence of voids at the interface, the current lines are not constricted, and no additional resistance is observed.4 Due to its frequency-dependent nature, this additional resistance can generally only be detected by impedance spectroscopy. During Li stripping, voids may form at the interface, resulting in a higher current density at the remaining contact areas during plating.5 This ultimately leads to the formation of Li dendrites, making the constriction effect the primary driver of a critical failure mechanism of ASSBs. In the present study, we present e...