Polymer-inorganic solid-electrolyte interphase for stable lithium metal batteries under lean electrolyte conditions

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• The solid-electrolyte interphase (SEI) is crucial for lithium metal anode stability in rechargeable batteries.
• Current SEI layers often reform and consume electrolytes, limiting battery lifespan and performance.
• Controlling SEI structure and stability remains a significant challenge in battery research.

Purpose of the Study:

• To design a molecular-level, stable solid-electrolyte interphase (SEI) that minimizes electrolyte consumption.
• To investigate a novel reactive polymer composite for SEI formation.
• To demonstrate the effectiveness of this approach for high-performance lithium metal batteries and other metal anodes.

Main Methods:

• Fabrication of a polymer-inorganic SEI layer using a reactive polymer composite.
• Characterization of the SEI structure using cryo-transmission electron microscopy, atomic force microscopy, and surface-sensitive spectroscopies.
• Electrochemical testing of lithium-ion cells with the novel SEI under demanding conditions (lean electrolyte, limited lithium excess).

Main Results:

• The polymer-inorganic SEI exhibits superior passivation, homogeneity, and mechanical strength compared to conventional SEI layers.
• The designed SEI effectively suppresses electrolyte consumption during battery cycling.
• High-efficiency lithium deposition and stable cycling of 4 V Li|LiNi0.5Co0.2Mn0.3O2 cells were achieved.
• The SEI design approach was successfully extended to sodium and zinc anodes.

Conclusions:

• A molecular-level SEI design using a polymer-inorganic composite offers a promising strategy for stabilizing metal anodes.
• This approach significantly improves battery performance by reducing electrolyte consumption and enhancing cycling stability.
• The developed SEI technology has broad applicability for next-generation rechargeable batteries, including lithium, sodium, and zinc systems.