2 research outputs found
Does Heat Play a Role in the Observed Behavior of Aqueous Photobatteries?
Light-rechargeable photobatteries have emerged as an
elegant solution
to address the intermittency of solar irradiation by harvesting and
storing solar energy directly through a battery electrode. Recently,
a number of compact two-electrode photobatteries have been proposed,
showing increases in capacity and open-circuit voltage upon illumination.
Here, we analyze the thermal contributions to this increase in capacity
under galvanostatic and photocharging conditions in two promising
photoactive cathode materials, V2O5 and LiMn2O4. We propose an improved cell and experimental
design and perform temperature-controlled photoelectrochemical measurements
using these materials as photocathodes. We show that the photoenhanced
capacities of these materials under 1 sun irradiation can be attributed
mostly to thermal effects. Using operando reflection
spectroscopy, we show that the spectral behavior of the photocathode
changes as a function of the state of charge, resulting in changing
optical absorption properties. Through this technique, we show that
the band gap of V2O5 vanishes after continued
zinc ion intercalation, making it unsuitable as a photocathode beyond
a certain discharge voltage. These results and experimental techniques
will enable the rational selection and testing of materials for next-generation
photo-rechargeable systems
Does Heat Play a Role in the Observed Behavior of Aqueous Photobatteries?
Light-rechargeable photobatteries have emerged as an
elegant solution
to address the intermittency of solar irradiation by harvesting and
storing solar energy directly through a battery electrode. Recently,
a number of compact two-electrode photobatteries have been proposed,
showing increases in capacity and open-circuit voltage upon illumination.
Here, we analyze the thermal contributions to this increase in capacity
under galvanostatic and photocharging conditions in two promising
photoactive cathode materials, V2O5 and LiMn2O4. We propose an improved cell and experimental
design and perform temperature-controlled photoelectrochemical measurements
using these materials as photocathodes. We show that the photoenhanced
capacities of these materials under 1 sun irradiation can be attributed
mostly to thermal effects. Using operando reflection
spectroscopy, we show that the spectral behavior of the photocathode
changes as a function of the state of charge, resulting in changing
optical absorption properties. Through this technique, we show that
the band gap of V2O5 vanishes after continued
zinc ion intercalation, making it unsuitable as a photocathode beyond
a certain discharge voltage. These results and experimental techniques
will enable the rational selection and testing of materials for next-generation
photo-rechargeable systems