title: An All-vanadium Continuous-flow Photoelectrochemical Cell for Extending State-of-charge in Solar Energy Storage.
abstract: Greater levels of solar energy storage provide an effective solution to the inherent nature of intermittency, and can substantially improve reliability, availability, and quality of the renewable energy source. Here we demonstrated an all-vanadium (all-V) continuous-flow photoelectrochemical storage cell (PESC) to achieve efficient and high-capacity storage of solar energy, through improving both photocurrent and photocharging depth. It was discovered that forced convective flow of electrolytes greatly enhanced the photocurrent by 5 times comparing to that with stagnant electrolytes. Electrochemical impedance spectroscopy (EIS) study revealed a great reduction of charge transfer resistance with forced convective flow of electrolytes as a result of better mass transport at U-turns of the tortuous serpentine flow channel of the cell. Taking advantage of the improved photocurrent and diminished charge transfer resistance, the all-V continuous-flow PESC was capable of producing ~20% gain in state of charge (SOC) under AM1.5 illumination for ca. 1.7 hours without any external bias. This gain of SOC was surprisingly three times more than that with stagnant electrolytes during a 25-hour period of photocharge.
authors.affiliation: Department of Mechanical Engineering, University of Massachusetts Lowell, Lowell, MA, 01854, USA.
authors.forename: Zi
authors.identifier: http://orcid.org/0000-0003-2751-3271
authors.initials: Z
authors.lastname: Wei
authors.affiliation: Department of Materials Science and Engineering, University of Texas at Arlington, Arlington, TX, 76019, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Department of Materials Science and Engineering, University of Texas at Arlington, Arlington, TX, 76019, USA.
authors.forename: Dong
authors.initials: D
authors.lastname: Liu
authors.affiliation: Department of Mechanical Engineering, University of Massachusetts Lowell, Lowell, MA, 01854, USA. fuqiang_liu@uml.edu.
authors.forename: Fuqiang
authors.initials: F
authors.lastname: Liu