Suppressing SEI Growth for Al Foil Anode under a Low Stack Pressure with Solid Polymer Electrolytes.

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Metal anodes, particularly aluminum (Al), are promising for high-capacity batteries but suffer from continuous solid-electrolyte interphase (SEI) growth.
• Solid-state electrolytes (SSEs) can mitigate SEI issues, but often require high pressure for effective contact with metal foils.
• Existing methods face challenges with pressure requirements and electrolyte infiltration into anode structures.

Purpose of the Study:

• To investigate the use of a soft polymer solid electrolyte for stabilizing Al foil anodes.
• To demonstrate that low pressure is sufficient to prevent SEI growth with polymer electrolytes.
• To enhance the performance and safety of solid-state batteries utilizing Al anodes.

Main Methods:

• Utilized a polymer electrolyte (PVDF-HFP) with an Al foil anode.
• Performed microstructural and compositional analyses on anode surfaces and cross-sections.
• Compared performance with liquid electrolytes under low-pressure conditions.

Main Results:

• The polymer electrolyte (PVDF-HFP) effectively suppressed SEI growth by avoiding infiltration into anode pits and pores.
• Achieved uniform Al lithiation reactions and significantly reduced SEI formation compared to liquid electrolytes.
• Demonstrated boosted Coulombic efficiency and improved cycling stability for the Al foil anode.

Conclusions:

• A soft polymer solid electrolyte enables stable Al anodes at practical low pressures.
• This approach offers a new strategy for developing safe and inexpensive solid-state batteries.
• The findings pave the way for advanced alloy anodes in next-generation energy storage devices.