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High Energy Efficiency and Stability for Photoassisted Aqueous Lithium–Iodine Redox Batteries
journal contribution
posted on 2016-09-21, 00:00 authored by Georgios Nikiforidis, Keisuke Tajima, Hye Ryung ByonWe demonstrated photoassisted lithium–iodine
(Li–I2) redox cells integrated with a hematite photoelectrode
that
are applicable to energy storage systems (ESSs). The hematite photoelectrode
presents low cost, light absorption in the visible light region, and
inertness to aqueous electrolytes, which allow for stable production
of photocurrent under illumination. In the aqueous Li–I2 redox cells, the harnessing of photoenergy generates photocarriers
that promote the I– oxidation process without electrolysis
of the aqueous solution. The energy efficiency for the photoassisted
charge process is ∼95.4%, which is ∼20% higher than
that in the absence of illumination at a current rate of 0.075 mA cm–2. The hematite is profoundly stable in aqueous I–/I3– catholyte and exhibits
over 600 h of cycling without noticeable performance decay and photocorrosion.
This achievement highlights photoinduced ESSs with improved energy
efficiency.