Solid state electrolyte systems boasting Li+ conductivity of >10 mS cm−1 at room temperature have opened the potential for developing a solid state battery with power and energy densities that are competitive with conventional liquid electrolyte systems. The primary focus of this review is twofold. First, differences in Li penetration resistance in solid state systems are discussed, and kinetic limitations of the solid state interface are highlighted. Second, technological challenges associated with processing such systems in relevant form factors are elucidated, and architectures needed for cell level devices in the context of product development are reviewed. Specific research vectors that provide high value to advancing solid state batteries are outlined and discussed.

Review—Practical Challenges Hindering the Development of Solid State Li Ion Batteries

Freeze casting – A review of processing, microstructure and properties via the open data repository, FreezeCasting.net

Li deposition is observed and measured on a solid electrolyte in the vicinity of a metallic current collector. Four types of ion-conducting, inorganic solid electrolytes are tested: Amorphous 70/30 mol% Li2S-P2S5, polycrystalline β-Li3PS4, and polycrystalline and single-crystalline Li6La3ZrTaO12 garnet. The nature of lithium plating depends on the proximity of the current collector to defects such as surface cracks and on the current density. Lithium plating penetrates/infiltrates at defects, but only above a critical current density. Eventually, infiltration results in a short circuit between the current collector and the Li-source (anode). These results do not depend on the electrolytes shear modulus and are thus not consistent with the Monroe–Newman model for “dendrites.” The observations suggest that Li-plating in pre-existing flaws produces crack-tip stresses which drive crack propagation, and an electrochemomechanical model of plating-induced Li infiltration is proposed. Lithium short-circuits through solid electrolytes occurs through a fundamentally different process than through liquid electrolytes. The onset of Li infiltration depends on solid-state electrolyte surface morphology, in particular the defect size and density.

Mechanism of Lithium Metal Penetration through Inorganic Solid Electrolytes

Solid oxide fuel cell: Decade of progress, future perspectives and challenges

Advanced ceramic components: Materials, fabrication, and applications

Current status and future directions of all-solid-state batteries with lithium metal anodes, sulfide electrolytes, and layered transition metal oxide cathodes

Freeze-casting for the fabrication of solid oxide fuel cells: A review

On the quality of tape-cast thin films of sulfide electrolytes for solid-state batteries

Tubular solid oxide fuel cells fabricated by a novel freeze casting method

Fabrication and Electrochemical Characterization of Freeze-Cast Tubular Solid Oxide Fuel Cells

Benjamin Emley

Papers

Current status and future directions of all-solid-state batteries with lithium metal anodes, sulfide electrolytes, and layered transition metal oxide cathodes

Freeze-casting for the fabrication of solid oxide fuel cells: A review

On the quality of tape-cast thin films of sulfide electrolytes for solid-state batteries

Tubular solid oxide fuel cells fabricated by a novel freeze casting method

Fabrication and Electrochemical Characterization of Freeze-Cast Tubular Solid Oxide Fuel Cells