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10:01
Thermal Scanning Conductometry TSC as a General Method for Studying and Controlling the Phase Behavior of Conductive Physical Gels
Published on: January 23, 2018
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Ionic Switches with Positive Temperature Coefficient Enabled by Phase Separation within Hydrogel Electrolytes.
Xiaoqing Ming1, Yang Xiang1, Le Yao1
1School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Shenzhen, Guangdong518172, P.R. China.
ACS Applied Materials & Interfaces
|October 6, 2022
Summary
This study introduces a novel solid-state ionic switch using poly(acrylic acid) hydrogel and calcium acetate. This device offers enhanced safety for electrochemical energy storage by preventing liquid leaking and volume shrinking.
Area of Science:
- Materials Science
- Electrochemistry
- Polymer Science
Background:
- Ionic switches are crucial for smart electrolytes in energy devices.
- Existing ionic switches face challenges like liquid leaking and volume shrinkage.
- Developing stable, solid-state ionic switches is essential for device longevity.
Purpose of the Study:
- To develop a novel positive temperature coefficient (PTC) ionic switch.
- To address limitations of current ionic switches, focusing on stability and safety.
- To demonstrate a new pathway for designing PTC ionic switches for energy storage devices.
Main Methods:
- Fabrication of a poly(acrylic acid) (PAA) hydrogel soaked with calcium acetate (CaAc).
- Investigation of the PTC effect attributed to heating-induced phase separation.
- Microstructure analysis to propose an ion channel model.
- Demonstration of a smart supercapacitor utilizing the PTC ionic switch.
Main Results:
- A stable, solid-state PTC ionic switch was successfully developed.
- The switch exhibited a significant resistance change (six times) due to phase separation.
- The device operated without liquid leaking or volume shrinking.
- A smart supercapacitor with safety protection was demonstrated.
Conclusions:
- The PAA/CaAc hydrogel-based PTC ionic switch offers a stable and safe alternative.
- The solid-state, isochoric nature overcomes limitations of conventional ionic switches.
- This research provides a new strategy for PTC ionic switch development in electrochemical energy storage.
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