Artificial Protective Interfacial Layer Functionalized by In Situ Constructed Hydrophobic...

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Aqueous zinc-ion batteries (AZIBs) are promising for large-scale energy storage.
• Challenges include zinc dendrite formation and interfacial side reactions due to unstable Zn-electrolyte interphases.

Purpose of the Study:

• To engineer a robust solid electrolyte interphase (SEI) for AZIBs.
• To suppress dendrite growth and interfacial side reactions for improved battery performance.

Main Methods:

• In situ grafting of poly(cyclotriphosphazene-co-4,4'-sulfonyldiphenol) (PZS) onto Zn surfaces via polycondensation.
• Characterization of the PZS interphase for mechanical strength, adhesion, hydrophobicity, and zinc-ion transport.
• Testing of symmetrical and asymmetrical cells, and a full Zn//MnO2 cell.

Main Results:

• The PZS interphase demonstrated mechanical strength and enhanced interfacial adhesion.
• PZS suppressed water-related side reactions and promoted fast Zn2+ desolvation.
• Uniform Zn deposition was achieved, leading to exceptional cycling stability (>2800 h in symmetrical cells) and high Coulombic efficiency (99.66%).
• The Zn//MnO2 full cell maintained 92.9% capacity retention after 1200 cycles.

Conclusions:

• The PZS-based multidefense interphase effectively addresses dendrite growth and side reactions in AZIBs.
• This interfacial engineering strategy offers a new paradigm for developing stable and durable AZIBs.