High-Performance Zinc-Bromine Rechargeable Batteries Enabled by In-Situ Formed Solid Electrolyte Interphase

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Aqueous zinc-bromine batteries (ZBBs) are attractive for renewable energy storage.
• Challenges like zinc dendrites and water decomposition limit ZBB cycle life and efficiency.

Purpose of the Study:

• To develop a facile strategy for enhancing ZBB performance.
• To suppress dendrite formation and water decomposition in ZBBs.

Main Methods:

• Coating graphite current collectors with a hydrophobic perfluoropolyether interlayer.
• In-situ formation of a fluorinated solid electrolyte interphase (SEI) during charging.
• Characterization of SEI properties and battery performance.

Main Results:

• Fluoride-rich SEI formation regulates zinc nucleation and suppresses dendrites.
• SEI inhibits hydrogen evolution by limiting water access.
• Reduced potential hysteresis (285 to 60 mV), energy density of 20 Wh L⁻¹, areal capacity of 10.7 mAh cm⁻².
• Maintained >79% energy efficiency over 1000 cycles.

Conclusions:

• The fluorinated SEI strategy offers a scalable approach for high-performance ZBBs.
• This advancement contributes to next-generation anode-free zinc batteries.
• Improved cycle life and energy efficiency were achieved.