Building Stable Anodes for High-Rate Na-Metal Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Sodium metal batteries (SMBs) offer low cost and high energy density, crucial for electric vehicles (EVs) and mobile electronics.
• High-rate operation in SMBs is hindered by sluggish sodium ion (Na+) kinetics at the sodium metal anode (SMA).
• SMA instability arises from unstable solid-electrolyte interfaces (SEI), sodium dendrite growth, and volume changes during cycling.

Purpose of the Study:

• To review key challenges in high-rate sodium metal anodes (SMAs).
• To highlight stabilization strategies for high-rate SMAs.
• To inspire further research for stable, high-energy metal batteries.

Main Methods:

• Surveying challenges in high-rate SMAs.
• Highlighting stabilization strategies for SMB components (host, Na metal surface, electrolyte, separator, cathode).
• Examining emerging solutions like solid-state SMBs and liquid metal anodes.

Main Results:

• Strategies focus on reducing Na nucleation energy barriers and promoting Na+ ion transfer kinetics.
• Modifications to SMB components and novel anode designs enhance SMA stability.
• Solid-state SMBs and liquid metal anodes present promising avenues for stable high-rate operation.

Conclusions:

• Stabilizing the sodium metal anode (SMA) is critical for high-rate sodium metal batteries (SMBs).
• A combination of component modification and advanced designs can overcome kinetic limitations.
• This review provides insights for developing next-generation high-energy metal batteries for sustainable energy solutions.