Self-charging energy harvester continuously generates electricity utilizing sodium ion movement in seawater

https://techxplore.com/news/2024-09-energy-harvester-generates-electricity-seawater.html

"multi-walled carbon nanotubes/ graphene oxide films with different oxygen functional groups as cathode and anode respectively, seawater electrolyte... more cations in electrolyte gather closer to anode, creating potential difference as result of ion rearrangement between 2 electrodes... high energy conversion efficiency, 24.6mW/cm3 power density, 4.2X higher... initial open circuit voltage restored without external energy... ocean sensors (temperature, dissolved oxygen, inorganic nitrogen) where device retrieval challenging"