Layered double hydroxide membrane with high hydroxide conductivity and ion selectivity for energy storage device

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Fast and selective ion transport membranes are crucial for advanced energy storage devices.
• Layered double hydroxides (LDHs) possess unique structural features, including uniform galleries and abundant hydroxyl groups, making them promising for membrane applications.
• Current research on LDHs for ion separation and their transport mechanisms remains limited.

Purpose of the Study:

• To develop and investigate a LDHs-based composite membrane for efficient ion transport in flow batteries.
• To elucidate the mechanisms governing hydroxide ion transport within the LDHs structure.
• To demonstrate the performance of LDHs membranes in practical energy storage applications.

Main Methods:

• Fabrication of a LDHs-based composite membrane.
• Investigation of ion transport mechanisms (vehicular and Grotthuss) using electrochemical techniques.
• Performance evaluation of the membrane in an alkaline zinc-based flow battery.

Main Results:

• The LDHs-based membrane exhibited fast and selective ion transport.
• Hydroxide ion transport was confirmed to occur via both vehicular and Grotthuss mechanisms within the LDHs.
• The membrane facilitated a zinc-based flow battery to operate at 200 mA cm⁻² with 82.36% energy efficiency over 400 cycles.

Conclusions:

• LDHs are highly effective materials for developing high-performance membranes for ion separation.
• Understanding ion transport mechanisms in LDHs provides fundamental insights for material design.
• This work paves the way for utilizing LDHs in various energy storage and conversion devices.