Disorder-driven sintering-free garnet-type solid electrolytes
Giyun Kwon, Hyeokjo Gwon, Youngjoon Bae, Changhoon Jung, Dong‐Su Ko, Min Gyu Kim, Kyungho Yoon, Gabin Yoon, Sewon Kim, In‐Sun Jung, Sangjun Lee, Tae‐Hee Kim, Ju‐Sik Kim, Tae Young Kim, Yong Su Kim
Abstract
Oxide ceramic electrolytes for realization of high-energy lithium metal batteries typically require high-temperature processes to achieve the desired phase formation and inter-particle sintering. However, such high-temperature processing can lead to compositional changes or mechanical deformation, compromising material reliability. Here, we introduce a disorder-driven, sintering-free approach to synthesize garnet-type solid electrolyte via the creation of an amorphous matrix followed by a single-step mild heat-treatment. The softened mechanical property (yield pressure, Py = 359.8 MPa) of disordered base materials enables the facile formation of a dense amorphous matrix and the preserving of inter-particle connectivity during crystallization. The formation of the cubic-phase garnet is triggered at a lowered temperature of 350 °C, achieving a Li+ ionic conductivity of 1.8 × 10–4 S/cm at 25 °C through a single-step mild heat treatment at 500 °C. The disorder-driven garnet solid electrolyte exhibits electrochemical performance comparable to conventional garnet solid electrolyte sintered at >1100 °C. These findings will promote the fabrication of uniform, thin, and wide solid electrolyte membranes, which is a significant hurdle in the commercialization of oxide-based lithium metal batteries, and demonstrate the untapped capabilities of garnet-type oxide solid electrolytes. Oxide ceramic electrolytes for Li-metal batteries often require high-temperature processing, which can compromise material reliability. Here, the authors present a sintering-free approach to synthesize disorder-driven garnet-type solid electrolytes, achieving performance comparable to traditional sintered materials.