Chemically Chargeable Photo Battery

Here we show a surrogate strategy for power production, wherein
light is used to actuate a discharge chemistry in the cathode of an
aqueous rechargeable battery (ARB). The proposed photo battery consists
of a titanium nitride photoanode, promising cathode material iron­(III)
hexacyanoferrate­(II) as the battery active species and Na2S2O8 as the chemical charging agent. The photo
battery delivered negligible capacity in the dark and the capacity
shot up to 77.8 mAh/g when artificially shined light, confirming that
the battery chemistry is light driven. In the ambient light, the device
retained 72% of its artificial light discharge capacity with a stable
cycling for more than 100 cycles. Further, an unprecedented means
for charging the battery rapidly is presented using Na2S2O8 and it revitalized the battery in 30 s
without any external bias. This methodology of expending a photoanode
extends to a battery that is free from dissolution of active materials,
irreversible structural changes, spontaneous deinsertion reactions,
and safety concerns commonly encountered in the state of the art anode
materials in ARBs. Apart from bringing out a sustainable way for power
production, this device opens up avenues for charging the battery
in the likely events of electrical input unavailability, while solving
the critcial issues of longer charging time and higher charging voltage.