2D MXene-containing polymer electrolytes for all-solid-state lithium metal batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Nanocomposite polymer electrolytes (CPEs) are crucial for developing safer all-solid-state lithium metal batteries (LMBs).
• MXenes, a class of 2D transition metal carbides/nitrides, offer unique properties like high aspect ratio and hydrophilic surfaces.
• Effective dispersion of nanofillers in polymer matrices is key to enhancing electrolyte performance.

Purpose of the Study:

• To fabricate novel MXene-based CPEs (MCPEs) for improved LMBs.
• To investigate the effect of MXene (Ti3C2Tx) incorporation on polymer electrolyte properties.
• To evaluate the electrochemical performance of MCPEs in solid-state LMBs.

Main Methods:

• A green, facile aqueous solution blending method was employed to disperse Ti3C2Tx MXene into a poly(ethylene oxide)/LiTFSI complex (PEO20-LiTFSI).
• The structural and electrochemical properties of the fabricated MCPEs were characterized.
• All-solid-state LMBs utilizing the MCPEs were assembled and tested for rate capability and long-term stability.

Main Results:

• MXene addition effectively retarded PEO crystallization and enhanced polymer segmental motion.
• The MCPE with 3.6 wt% MXene exhibited the highest ionic conductivity (2.2 × 10-5 S m-1 at 28 °C).
• An LMB with only 1.5 wt% MXene demonstrated rate capability and stability comparable to state-of-the-art CPE-LMBs.

Conclusions:

• MXenes are highly efficient nanofillers for enhancing ionic conductivity and electrochemical performance in polymer electrolytes.
• The 2D geometry, uniform dispersion, and functionalized surface of MXenes contribute to superior electrolyte properties.
• MXene-based CPEs show significant promise for advanced all-solid-state lithium metal batteries.