title: A Thermally-Regenerative Ammonia-Based Flow Battery for Electrical Energy Recovery from Waste Heat.
abstract: Large amounts of low-grade waste heat (temperatures <130 °C) are released during many industrial, geothermal, and solar-based processes. Using thermally-regenerative ammonia solutions, low-grade thermal energy can be converted to electricity in battery systems. To improve reactor efficiency, a compact, ammonia-based flow battery (AFB) was developed and tested at different solution concentrations, flow rates, cell pairs, and circuit connections. The AFB achieved a maximum power density of 45 W m(-2) (15 kW m(-3) ) and an energy density of 1260 Wh manolyte (-3) , with a thermal energy efficiency of 0.7 % (5 % relative to the Carnot efficiency). The power and energy densities of the AFB were greater than those previously reported for thermoelectrochemical and salinity-gradient technologies, and the voltage or current could be increased using stacked cells. These results demonstrated that an ammonia-based flow battery is a promising technology to convert low-grade thermal energy to electricity.
authors.affiliation: Department of Civil and Environmental Engineering, Penn State University, University Park, PA, 16802, USA.
authors.forename: Xiuping
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Department of Chemical Engineering, Penn State University, University Park, PA, 16802, USA.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Rahimi
authors.affiliation: Department of Civil and Environmental Engineering, Penn State University, University Park, PA, 16802, USA.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Gorski
authors.affiliation: Department of Civil and Environmental Engineering, Penn State University, University Park, PA, 16802, USA. blogan@psu.edu.
authors.forename: Bruce
authors.identifier: 0000-0001-7478-8070
authors.initials: B
authors.lastname: Logan
mesh_terms: D000641:Ammonia / Q000737:chemistry*; D011211:Electric Power Supplies; D004560:Electricity; D004573:Electrolytes; D006358:Hot Temperature; D059027:Recycling
chemical_list: D004573:Electrolytes; D000641:Ammonia
keywords: ammonia; energy conversion; flow battery; sustainable chemistry; thermal energy