Problem
Electrolytes are susceptible to reductive decomposition on the surface of negative electrodes, leading to the formation and growth of a solid-electrolyte interphase (SEI) layer which significantly affects battery performance. In particular, Li dendrite growth during cycling can result in short-circuiting of the battery if the dendrite reaches the positive electrode. All-solid-state lithium-metal batteries (ASSLMBs) have garnered considerable attention, especially for next-generation electric vehicles, due to their advantages in energy storage capacity and safety. However, the large interfacial impedance from poor physical contact and/or parasitic reactions at the Li/SSE interface hinders the development of ASSLMs. To make further advances in battery technologies, especially for EVs, it is critical to devise strategies for the formation of an effective interfacial layer at the electrode/electrolyte interface that can suppress electrolyte decomposition and Li dendrite propagation by blocking electron transport, while allowing Li ions to travel through it during cycling.
Solution
Incorporation of heteroelements in a sufficient amount into lithium fluoride (LiF) makes it possible to form the amorphous structure under ambient and battery operating conditions. The amorphous phases of LiF and LiF-rich inorganic materials exhibit exceptional properties and show great promise for use as an interfacial protective layer at electrode/electrolyte interfaces in ASSLMBs and LIBs.
Features
- Methods to synthesize and stabilize the amorphous phases of LiF and LiF-rich inorganic thin layers under ambient and battery operating conditions
- Compositions and structures of LiF-rich inorganic materials that show excellent Li-ion transport properties, electron blocking ability, and desirable mechanical and interfacial properties
- Ability to form the thin amorphous LiF layer, both ex situ and in situ, at the electrode/electrolyte interface
Benefits
The ability to synthesize and stabilize amorphous LiF and LiF-rich thin layers will greatly contribute to solve the interfacial problems, which will in turn help realize next-generation rechargeable Li and Li-ion batteries, particularly ASSLMBs for EVs.
Markets
Li-ion battery manufacturers including SK Innovation. Market size is projected to grow from $22.7 billion in 2018 to $47.4 billion by 2023, at a 5yr CAGR of 15.8% [Lithium Batteries: Markets and Materials, BCC Research, May 2019].
