Opportunity
Zinc (Zn) batteries, particularly rechargeable zinc batteries (RZBs), are promising energy storage solutions due to their safety, low cost, and environmental friendliness. However, a critical challenge in their commercialization is the corrosion of zinc anodes when coupled with copper (Cu) current collectors, a common configuration in industrial production. In such setups, Zn powder (Zn-P) is preferred over Zn foil for scalability, but the Zn-P@Cu anode suffers from severe galvanic corrosion. This corrosion leads to hydrogen gas generation (e.g., 10.1 µmol cm⁻² on Cu surfaces) and Zn dissolution, causing battery swelling, capacity loss, and shortened lifespan. For instance, after 120 hours of aging, the Zn-P layer deteriorates, and cycling performance drops to 31 mAh g⁻¹ after 300 cycles. These issues hinder the reliability and longevity of Zn batteries, creating a pressing need for innovative anode designs that mitigate corrosion while maintaining practical manufacturability.
Technology
The patent introduces a novel anode architecture to address galvanic corrosion in Zn batteries. The key innovation involves inserting a tin (Sn) substrate between the Zn powder and the Cu current collector (denoted Zn-P@Sn-Cu). Sn acts as a protective interlayer due to its higher hydrogen evolution overpotential, reducing corrosion by 3.5 µmol cm⁻² during aging and cutting hydrogen production during cycling by 87.5% (from 57 µmol cm⁻² to 7.9 µmol cm⁻²). Alternatively, titanium (Ti) can replace Cu as the current collector (Zn-P@Ti), leveraging Ti’s inertness in aqueous electrolytes. The Sn-coated Cu is fabricated via electroplating in a solution containing SnCl₂, NaH₂PO₂, and HCl, followed by applying a Zn-P slurry (97:3 mass ratio of Zn powder to PVDF/PTFE binder) mixed with conductive agents like carbon nanotubes. This design preserves Zn integrity, enabling 101 mAh g⁻¹ capacity after 300 cycles—a 225% improvement over Zn-P@Cu.
Advantages
- Corrosion Mitigation: Sn interlayer reduces hydrogen generation by 87.5% and Zn dissolution.
- Improved Cycle Life: Achieves 101 mAh g⁻¹ after 300 cycles vs. 31 mAh g⁻¹ for conventional Zn-P@Cu.
- Scalable Manufacturing: Uses industrially viable Zn powder and electroplating processes.
- Flexible Configurations: Compatible with Ti current collectors for enhanced inertness.
- Reduced Swelling: Limits battery deformation by minimizing gas evolution.
Applications
- Rechargeable Zn Batteries (RZBs): For grid storage, EVs, and portable electronics.
- Aqueous Batteries: Safe, non-flammable energy storage systems.
- Hybrid Anodes: Pairable with MnO₂, V₂O₅, or Prussian blue cathodes.
- Consumer Electronics: Low-cost, long-life batteries for devices.
