Weak H-Bond Interface Environment for Stable Aqueous Zinc Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Aqueous zinc-based batteries face limitations from hydrogen evolution reaction and zinc dendrite growth.
• These issues stem from high water activity and imbalanced electrochemical kinetics versus mass transfer.
• Commercial application of these batteries is hindered by these constraints.

Purpose of the Study:

• To develop a strategy to mitigate hydrogen evolution and zinc dendrite growth in aqueous zinc-based batteries.
• To improve the electrochemical performance and cycle life of these battery systems.
• To explore the versatility of the developed strategy across different zinc salt systems and full cells.

Main Methods:

• Introduction of titanium dioxide (TiO2) nanoparticles into the electrolyte to form a suspension.
• Creation of a weak hydrogen-bond interface via hydroxyl functional groups on the TiO2[110] surface.
• Disruption of water molecule hydrogen-bond networks to reduce water activity and enhance Zn2+ mass transfer.

Main Results:

• The TiO2-based suspension electrolyte significantly reduces water activity and accelerates Zn2+ mass transfer.
• Zn||Zn symmetrical cells demonstrated reversible zinc plating/stripping with 99.7% Coulombic efficiency over 700 cycles.
• The strategy proved effective in other zinc salt systems and enabled stable performance in full cells (Zn||PANI, Zn||ZnVO).

Conclusions:

• The weak H-bond interface strategy using TiO2 nanoparticles is a promising approach for high-performance aqueous zinc-based batteries.
• This method effectively addresses key challenges like hydrogen evolution and dendrite formation.
• The suspension electrolyte offers a versatile solution for advancing zinc-based energy storage technologies.