Synergistic polypyrrole coating and electrolyte engineering toward high-performance Zn-based batteries

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Aqueous zinc-ion batteries (ZIBs) face challenges like dendrite formation, hydrogen evolution, and passivation at the anode.
• These issues limit the stability and lifespan of ZIB devices.

Purpose of the Study:

• To develop an effective strategy for regulating zinc ion (Zn²⁺) reduction kinetics at the anode.
• To enhance the electrochemical performance and practical viability of ZIBs.

Main Methods:

• Utilizing a composite anode material incorporating polypyrrole (PPy).
• Incorporating citric acid (CA) and sodium sulfate (Na₂SO₄) as additives to modify the anode.
• Conducting symmetric cell cycling tests to evaluate anode stability and polarization.
• Assembling and testing full cells with α-MnO₂ cathodes.

Main Results:

• The modified anode demonstrated stable cycling for over 400 hours in a symmetric cell at 1 mA cm^-2 and 1 mA h cm^-2.
• A low polarization voltage of 45 mV was achieved with the modified anode.
• The full cell exhibited a retained capacity of 140 mA h g^-1 after 2000 cycles.

Conclusions:

• The PPy/CA/Na₂SO₄ modified anode effectively suppresses detrimental anode behaviors in ZIBs.
• The enhanced anode performance significantly improves the cycling stability and longevity of aqueous zinc-ion batteries.
• The findings highlight the practical potential of this modified anode for future energy storage applications.