title: Batteries for efficient energy extraction from a water salinity difference.
abstract: The salinity difference between seawater and river water is a renewable source of enormous entropic energy, but extracting it efficiently as a form of useful energy remains a challenge. Here we demonstrate a device called "mixing entropy battery", which can extract and store it as useful electrochemical energy. The battery, containing a Na(2-x)Mn(5)O(10) nanorod electrode, was shown to extract energy from real seawater and river water and can be applied to a variety of salt waters. We demonstrated energy extraction efficiencies of up to 74%. Considering the flow rate of river water into oceans as the limiting factor, the renewable energy production could potentially reach 2 TW, or ∼13% of the current world energy consumption. The mixing entropy battery is simple to fabricate and could contribute significantly to renewable energy in the future.
authors.affiliation: Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States.
authors.forename: Fabio
authors.initials: F
authors.lastname: La Mantia
authors.forename: Mauro
authors.initials: M
authors.lastname: Pasta
authors.forename: Heather D
authors.initials: HD
authors.lastname: Deshazer
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Logan
authors.forename: Yi
authors.initials: Y
authors.lastname: Cui
mesh_terms: D011211:Electric Power Supplies; D004563:Electrochemistry / Q000295:instrumentation*; D004566:Electrodes; D004735:Energy Transfer; D004867:Equipment Design; D019544:Equipment Failure Analysis; D036103:Nanotechnology / Q000295:instrumentation*; D012965:Sodium Chloride / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water; D012965:Sodium Chloride