Liquid Metal Loaded Molecular Sieve: Specialized Lithium Dendrite Blocking Filler for Polymeric Solid-State...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• All-solid-state lithium metal batteries (LMBs) promise high energy density and safety.
• Polyethylene oxide (PEO) is a common solid-state electrolyte (SSE) but suffers from lithium dendrites and low ionic conductivity.
• Improving SSEs is crucial for next-generation batteries.

Purpose of the Study:

• To develop a composite electrolyte that enhances ionic conductivity and prevents lithium dendrite formation in LMBs.
• To investigate the role of molecular sieve (MS) and liquid metal (LM) in a PEO-based SSE.
• To improve the safety and cycle life of all-solid-state LMBs.

Main Methods:

• Integration of molecular sieve (MS) as an inert filler and liquid metal (LM) as a functional module into polyethylene oxide (PEO).
• Formation of an "LM-MS-PEO" composite serving as both SSE and a dendrite protection layer.
• Theoretical and experimental investigations of ion transport and dendrite suppression mechanisms.

Main Results:

• Uniform distribution of LM within PEO, preventing agglomeration and effectively blocking lithium dendrites.
• Reduced PEO crystallinity and improved lithium-ion conductivity due to MS.
• Fourfold increase in ionic conductivity of LM-MS-PEO compared to pristine PEO at 40 °C.
• Four to five times longer stable cycle life for LMBs utilizing the composite electrolyte.

Conclusions:

• The "LM-MS-PEO" composite functions as an effective SSE and a robust barrier against lithium dendrites.
• The composite material significantly enhances ionic conductivity and battery cycle life.
• This approach offers a promising strategy for developing safe and high-performance all-solid-state lithium metal batteries.