Gaseous SO₂ Additive for High-Energy-Density Li-Ion Battery

Area of Science:

• Electrochemistry
• Materials Science
• Sustainable Energy

Background:

• Electrolyte additive engineering is crucial for improving the performance of high-energy-density batteries.
• Conventional additives often suffer from high costs, instability, and limited effectiveness in interfacial passivation.

Purpose of the Study:

• To develop a sustainable and cost-effective electrolyte additive strategy for advanced batteries.
• To leverage industrial waste gases for enhanced battery performance and stability.

Main Methods:

• Utilizing sulfur dioxide (SO2) as a dual-functional gaseous electrolyte additive.
• Investigating the electrochemical reactions of SO2 for in situ interphase formation on battery electrodes.
• Testing the performance of pouch cells with SO2 additive under various conditions.

Main Results:

• SO2 promotes the formation of sulfur-containing interphases, suppressing electrolyte decomposition.
• 4.4 V-class AG || NCM613 pouch cells achieved over 800 cycles with 88.2% capacity retention.
• The strategy demonstrated broad applicability in 4.3 V-class Si/C || NCM811 pouch cells and improved temperature tolerance (-30°C to 45°C).

Conclusions:

• Sulfur dioxide is a highly effective, dual-functional additive for enhancing battery cycling stability and temperature tolerance.
• This approach offers a sustainable pathway by valorizing industrial waste into high-performance battery components.
• The strategy reduces electrolyte discoloration, extends shelf life, and lowers costs, aligning environmental goals with energy storage innovation.