Make it flow from solid to liquid: Redox-active electrofluids for intrinsically stretchable batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Wearable Technology

Background:

• High-capacity stretchable batteries are essential for advanced wearables, but current designs struggle to balance energy density with mechanical flexibility.
• Increasing active material in solid electrodes often compromises their mechanical properties, leading to stiffness and reduced performance.

Purpose of the Study:

• To introduce a new concept for stretchable batteries using fluid electrodes.
• To overcome the trade-off between high capacity and mechanical deformability in stretchable battery designs.

Main Methods:

• Transferred the electrode's physical properties from a solid to a fluid state, utilizing fluid viscosity for mechanical and electrochemical performance.
• Developed a redox-active electrofluid that decouples electrochemical and mechanical properties.

Main Results:

• Achieved higher active material loading and capacity without increasing cell stiffness.
• Demonstrated excellent capacity retention over 500 charge-discharge cycles.
• Showcased mechanical robustness withstanding up to 100% strain.

Conclusions:

• The fluid electrode concept offers a viable solution for high-capacity, mechanically robust stretchable batteries.
• This approach enables improved performance and conformability for next-generation wearable electronic devices.