Pure bulk ion-conducting membrane for high-energy-density batteries

• Published in: Journal of power sources Vol. 482; p. 229025
• Main Authors: Choi, Wonsung, Choi, Kyoung H., Kim, Tae Y., Sugimoto, Toshinori, Kim, Youngeal, Kitajima, Shintaro, Kim, Mokwon, Kim, Hyunjin, Lee, Hyunpyo, Kwon, Hyuk Jae, Lee, Heung C., Lee, Dongjoon, Park, Jung O., Kim, Jung-Hwa, Park, Seong Y., Im, Dongmin
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-01-2021
• Subjects: Impedance; Lithium metal; Lithium–air battery; Membrane; Single crystal; Solid electrolyte; Lithium metal; Lithium–air battery; Membrane; Impedance; Single crystal; Solid electrolyte
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2020.229025

Solid electrolytes (SE) are key components for the safe and continuous operation of high-energy lithium metal batteries. Metal oxide SEs, which are stable under ambient conditions, are used as separators in the form of thick and heavy plates; however, this reduces the specific energy of practical battery cells. Despite considerable efforts, the development of thin SE separators with high ionic conductivities has remained a significant challenge. This paper reports the scalable production of a thin membrane comprising single-crystal SE particles that are bicontinuously embedded in a polymer matrix to form ion-conducting channels. The membrane exhibits a high ionic conductivity of 6.0 × 10−4 S cm−1 with remarkably low activation energy (20-times greater than that of current membranes with polycrystalline SE particles), eliminating large grain boundary resistances. The high conductivity enables stable lithium metal stripping and plating, producing a homogeneous ion flow to the lithium metal. Furthermore, a lithium metal–air battery cell using the membrane demonstrates a high specific energy of 700 Wh kg−1.
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•Li-ion conducting membrane using single-crystal Li1.3Al0.3Ti1.7(PO4)3 particles.•The solid electrolyte embedded membrane is prepared by a scalable wet-process.•High ion conductivity of the membrane is 6.0 × 10−4 S cm−1 with an Ea of 0.18 eV.•A Li–air battery cell using the membrane exhibits a specific energy of 700 Wh kg−1.