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

TLDR

Solid state electrolyte systems with Li⁺ conductivity >10 mS cm⁻¹ at room temperature enable batteries whose power and energy densities rival conventional liquid‑electrolyte systems. The review aims to identify practical challenges hindering solid‑state battery development and to outline high‑value research vectors that can accelerate progress. It discusses Li‑penetration resistance and kinetic limitations at the solid‑state interface, and examines processing challenges and the architectures needed for cell‑level devices in product development.

Abstract

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.