V₂CT MXene modification enabling stable sodium metal anodes.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Sodium metal batteries (SMBs) are promising for next-generation energy storage due to sodium's high theoretical capacity.
• However, uncontrolled sodium dendrite growth during cycling leads to poor reversibility and safety hazards.
• Developing stable and efficient anodes is crucial for advancing SMB technology.

Purpose of the Study:

• To investigate the use of V₂CT MXene as a host material for sodium metal anodes.
• To evaluate the impact of V₂CT MXene on the sodium plating/stripping behavior and electrochemical performance of SMBs.
• To provide a feasible strategy for achieving dendrite-free and highly reversible sodium metal anodes.

Main Methods:

• A simple mechanical mixing strategy was employed to directly incorporate V₂CT MXene with metallic sodium.
• The electrochemical performance of the composite anode was evaluated using Na plating/stripping tests in Na metal batteries.
• Surface functional groups of V₂CT MXene were analyzed for their role in sodium ion deposition.

Main Results:

• The V₂CT MXene host effectively enabled highly reversible and dendrite-free sodium plating/stripping.
• Uniform Na⁺ deposition was observed on the V₂CT anode, attributed to abundant -O and -F surface functional groups.
• The composite anode demonstrated significantly improved electrochemical performance compared to bare sodium metal.

Conclusions:

• Direct incorporation of V₂CT MXene with metallic sodium provides a viable strategy for developing stable sodium metal anodes.
• The surface functional groups of V₂CT MXene play a critical role in promoting uniform sodium deposition.
• This work offers a promising approach to enhance the safety and performance of sodium metal batteries.