The Seawater Battery

After soaking in salty water, these rechargeable strands lit up LEDs (top image) and powered a timer (bottom image). Adapted from ACS Applied Materials & Interfaces 2024, DOI: 10.1021/acsami.4c16439
January 21, 2025 – Researchers from the School of Materials and Energy at Southwest University, Chongqing (China), have developed a ‘yarn-like’ battery that functions when immersed in seawater. The concept is that such a battery could power items like fishing nets, life jackets, or mooring lines for buoys.
To create the electrodes for the seawater battery, the team treated bundles of carbon fibre with electrically conductive coatings: nickel hexacyanoferrate for the positive electrode (cathode) and polyamide for the negative electrode (anode). They then braided the treated bundles into yarn-like cathode and anode strands to produce a prototype. The resulting battery resembles a knitted piece of fabric. When immersed in saltwater, the seawater serves as the electrolyte. The prototype successfully illuminated a panel of 10 LEDs.
This research was previously published in ACS Applied Materials & Interfaces under the title ‘Constructing High-Performance Yarn-Shaped Electrodes via Twisting-after-Coating Technique for Weavable Seawater Battery.’