Universal Chemomechanical Design Rules for Solid-Ion Conductors to Prevent Dendrite Formation in Lithium Metal Batteries

Abstract

Dendrite formation during electrodeposition while charging lithium metal batteries compromises their safety. While high shear modulus solid-ion conductors (SICs) have been prioritized to resolve pressure-driven instabilities that lead to dendrite propagation and cell shorting, it is unclear whether these or alternatives are needed to guide uniform lithium electrodeposition, which is intrinsically density-driven. Here, we show that SICs can be designed within a universal chemomechanical paradigm to access either pressure-driven dendrite-blocking or density-driven dendrite-suppressing properties, but not both. This dichotomy reflects the competing influence of the SICs mechanical properties and partial molar volume of Li+ relative to those of the lithium anode on plating outcomes. Within this paradigm, we explore SICs in a previously unrecognized dendrite-suppressing regime that are concomitantly soft, as is typical of polymer electrolytes, but feature atypically low Li+ partial molar volume, more reminiscent of hard ceramics. Li plating mediated by these SICs is uniform, as revealed using synchrotron hard x-ray microtomography. As a result, cell cycle-life is extended, even when assembled with thin Li anodes and high-voltage NMC-622 cathodes, where 20 percent of the Li inventory is reversibly cycled.

References in corpus (4)

• A real-space grid implementation of the Projector Augmented Wave method
• Stable Lithium Electrodeposition in Liquid and Nanoporous Solid Electrolytes
• Stability of Electrodeposition at Solid-Solid Interfaces and Implications for Metal Anodes
• Stability and surface diffusion at lithium-electrolyte interphases with connections to dendrite suppression

Cited by in corpus (5)

• Interfacial Effects on Solid Electrolyte Interphase in Lithium-ion Batteries
• Design rules for liquid crystalline electrolytes for enabling dendrite-free lithium metal batteries
• Chemomechanics: friend or foe of the "AND problem" of solid-state batteries?
• Grain Boundaries in Ceramic Solid-State Lithium Metal Batteries: A Review
• Harnessing Structural and Dynamic Heterogeneity to Direct Ion Transport in Plastic Crystal-Polymer Composite Solid-Ion Conductors