Decoupling Ion-Dipole Interactions via Competitive Coordination for Durable Dendrite-Free Zinc Metal Batteries

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Aqueous zinc metal batteries (AZMBs) offer high safety and energy density.
• Challenges include strong Zn²⁺-H₂O interactions at the Helmholtz plane, hindering ion transport and desolvation.
• This limits AZMB performance and lifespan.

Purpose of the Study:

• To reconstruct the Helmholtz plane environment in AZMBs.
• To weaken Zn²⁺-H₂O interactions and accelerate desolvation kinetics.
• To enhance the overall performance and stability of AZMBs.

Main Methods:

• Interface chemistry modification using L-Carnosine (L-CN) with a high permanent dipole moment.
• Reconfiguration of the inner Helmholtz plane layer by weakening Zn²⁺-H₂O interactions.
• Testing Zn//Zn symmetric cells and Zn//V₂O_5-x full cells with optimized electrolytes.

Main Results:

• L-CN successfully weakened Zn²⁺-H₂O interactions, creating a crowded Zn²⁺-conductive structure.
• Desolvation kinetics were accelerated, and hydrogen evolution reactions were inhibited.
• Zn//Zn symmetric cells achieved 7000 h lifespan, 99.72% Coulombic efficiency, and high stabilization at 85.4% depth of discharge.
• A Zn//V₂O_5-x full cell delivered 289 mAh g^-1 after 500 cycles.
• Large-scale pouch cells stabilized for 200 cycles.

Conclusions:

• Helmholtz plane reconstruction using L-CN is a viable strategy for high-performance AZMBs.
• This approach significantly improves ion transport, battery lifespan, and stability.
• The findings present a promising future for advanced AZMBs.