Stabilizing Zn anode for high-performance Zn-Ni battery through a complexing agent electrolyte addition.

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Zinc-nickel (Zn-Ni) batteries offer high energy density and stable voltage but suffer from poor cycling stability.
• Anode interface issues, including dendrite growth and side reactions, hinder the commercialization of Zn-Ni batteries.

Purpose of the Study:

• To optimize the zinc anode interfacial environment in Zn-Ni batteries.
• To enhance the cycling stability of Zn-Ni batteries through electrolyte engineering.

Main Methods:

• Introduction of tannic acid (TA) as a complexing agent into the potassium hydroxide (KOH) electrolyte.
• Investigation of TA's role in preventing water contact and promoting Zn2+ desolvation at the anode interface.
• Testing of Zn symmetric and Zn-Ni full batteries with the modified electrolyte.

Main Results:

• The Zn anode in the TA-modified electrolyte exhibited stable cycling for 178 hours at 1 mA cm⁻².
• Zn-Ni full batteries with TA electrolyte demonstrated excellent capacity retention of 98.08% after 2000 cycles at 20C.
• The TA addition effectively suppressed interfacial corrosion and dendrite formation.

Conclusions:

• Electrolyte engineering using tannic acid is a facile and effective strategy to stabilize the Zn anode in Zn-Ni batteries.
• This approach significantly improves the cycling stability and longevity of Zn-Ni batteries.
• The findings pave the way for the commercialization of large-scale, practical energy storage applications.