Mitigating Battery Cell Failure: Role of Ag‐Nanoparticle Fillers in Solid Electrolyte Dendrite Suppression

The incorporation of silver nanoparticles into sulfide-based solid electrolytes is shown to suppress lithium dendrite growth and stress-induced failure. Combining advanced 3D tomography, electrochemical testing, and modeling, this study reveals how Ag nanoparticles redirect Li currents, homogenize filament growth, and prevent short-circuiting in the pore-percolating regime, offering new design principles for solid-state batteries.

Abstract

The development of solid-state batteries (SSBs) with lithium Li metal anodes holds significant promise for enhancing the energy density and safety of next-generation energy storage systems. However, their commercialization is hindered by challenges related to Li dendrite formation, which can lead to short circuits and battery failure. In this study, the role of Ag nanoparticles embedded within solid electrolytes (SE) is investigated in suppressing dendrite propagation. The results demonstrate that Ag nanoparticles effectively mitigate two key failure mechanisms: (1) dendrite growth within porous networks at low current densities and (2) stress intensification-induced SE fracture at higher current densities (12 mA cm⁻²). Ex situ characterization using focused-ion beam – scanning electron microscopy (FIB–SEM) and energy dispersive X-ray spectroscopy (EDS,) reveals that Ag nanoparticles migrate alongside advancing Li dendrites, promoting homogeneous dendrite growth and reducing the likelihood of localized stress concentrations. Additionally, the incorporation of Ag nanoparticles is shown to facilitate a more uniform Li distribution toward the anode side, which can potentially enable the use of higher charging rates in SSBs. This study provides a new perspective on Li dendrite suppression and presents new opportunities for enhancing the performance and safety of SSBs.