Hydrolysis of Solid Buffer Enables High-Performance Aqueous Zinc Ion Battery

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Aqueous zinc ion batteries (AZIBs) offer safety and low cost but suffer from anode/electrolyte interface (AEI) instability.
• Key challenges include hydrogen evolution, Zn corrosion, dendrite growth, and by-product accumulation at the AEI.

Purpose of the Study:

• To develop a comprehensive and enduring solution for AEI issues in AZIBs.
• To investigate the use of black phosphorus (BP) hydrolysis for in-situ SEI formation and stabilization.

Main Methods:

• Utilized 2D layered black phosphorus (BP) as a hydrolytic solid buffer in aqueous electrolytes.
• Analyzed the formation of a zinc phosphate (ZPO) rich solid electrolyte interphase (SEI) layer.
• Evaluated the performance of BP-modified separators in Zn||Zn symmetrical cells and V2O5·nH2O//Zn full cells.

Main Results:

• Hydrolysis of BP generated phosphoric acid, forming a ZPO-rich SEI layer that suppressed dendrite growth, corrosion, and hydrogen evolution.
• The phosphoric acid stabilized local pH, preventing alkaline by-product accumulation.
• BP-modified separators demonstrated over a tenfold lifespan enhancement in Zn||Zn symmetrical cells.
• High-loading V2O5·nH2O cathodes showed significantly improved cumulative capacities in coin and pouch cells.

Conclusions:

• The BP hydrolysis strategy provides a durable and effective method for stabilizing the AEI in AZIBs.
• This approach offers a superior alternative to pre-constructed SEI layers or electrolyte additives.
• The developed technology significantly advances the practical application of high-performance and long-lasting aqueous zinc ion batteries.