Thin, flexible secondary Li-ion paper batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Growing demand for thin, flexible energy storage in modern applications.
• Limitations of conventional energy storage devices in terms of flexibility and form factor.

Purpose of the Study:

• To develop a novel thin, flexible lithium-ion (Li-ion) battery structure.
• To utilize paper as a substrate and separator, and carbon nanotube (CNT) films as current collectors.

Main Methods:

• Integration of Li-ion battery materials onto a single sheet of paper via lamination.
• Utilizing paper as a mechanical substrate and separator membrane.
• Employing free-standing CNT thin films as lightweight, flexible current collectors for both anode and cathode.

Main Results:

• The paper-based battery achieved a low impedance separator and low sheet resistance CNT current collectors (∼5 Ohm/sq).
• The resulting rechargeable Li-ion paper battery is thin (∼300 μm) with robust mechanical flexibility (<6 mm bending radius).
• Demonstrated high energy density of 108 mWh/g.

Conclusions:

• The developed paper-based Li-ion battery structure offers a promising solution for flexible energy storage.
• The use of paper and CNT films provides a lightweight, flexible, and cost-effective alternative to conventional batteries.
• This technology is suitable for applications requiring integrated, flexible power sources.