Foldable water-activated reserve battery with diverse voltages

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Reserve batteries are typically inert until activated by an electrolyte, limiting their applications.
• Existing reserve batteries lack flexibility and foldability, hindering technological advancement.
• There is a need for novel reserve battery designs that offer enhanced mechanical properties and activation versatility.

Purpose of the Study:

• To fabricate a flexible and foldable reserve battery.
• To investigate the battery's performance when activated by various solutions.
• To assess the impact of folding on the battery's discharge performance.

Main Methods:

• Fabrication of a reserve battery using a cellulose and carbon nanotube paper cathode and an aluminum anode.
• Activation of the battery with different electrolyte solutions (NaCl, KOH, seawater).
• Electrochemical characterization including voltage measurements and impedance analysis.
• Testing of the battery's performance in both folded and unfolded states.

Main Results:

• The reserve battery demonstrated activation with NaCl (approx. 0.7 V) and KOH (approx. 1.3 V) solutions.
• Impedance analysis indicated optimal discharge performance correlated with the smallest semicircle in impedance spectra.
• Folding the battery did not significantly degrade its discharge performance.
• Successful activation and good discharge performance were observed using seawater.

Conclusions:

• A flexible and foldable reserve battery system activated by various solutions has been successfully demonstrated.
• The developed battery technology shows potential for broader applications requiring adaptable and robust energy storage.
• This work opens avenues for extending the flexibility and foldability concepts to other reserve battery designs.