Bringing out a sustainable way for power production, Indian researchers have developed a novel photo battery technology that uses light to drive battery power safely.
Metal-ion batteries that run most of our gadgets take a long time to charge. They can also overheat and catch fire if they’re defective or damaged. These problems are often related to the unstable material used for the anode, the negative side of the battery.
To overcome this problem, the researchers developed the battery with light and titanium nitride (TiN) as its anode. The cathode is made of iron(III) hexacyanoferrate(II) and sodium persulfate is the chemical charging agent.
TiN was chosen as the photoelectrode because of the presence of a native oxynitride layer on its surface which can absorb visible part of the solar spectrum and its good electronic conductivity and high corrosion resistance.
The working principle involves the light assisted generation of electron–hole pairs in TiN and the pumping of generated photoelectrons to iron(III) hexacyanoferrate(II). This reduces the photoelectrons to iron(II) hexacyanoferrate(II), with simultaneous Potassium ion insertion, thereby generating power.
The photo battery delivered negligible capacity in the dark and the capacity shot up to 77.8 mAh/g when artificially shined light. In the ambient light, the device retained 72% of its artificial light discharge capacity with a stable cycling for more than 100 cycles.
Under normal indoor lighting, it discharged electric current and recharged within 30 seconds without an external power source.
Although not yet strong enough to run commercially available devices, the researchers say their design is a promising first step toward a more sustainable and safer battery technology.
Since the battery works using ambient light, it may be able to produce power even in the presence of street light, household lighting, indoor lighting, and so on. The possibilities of self-regeneration using chemical charging agents open avenues for continuous power production in the likely events of electrical input being unavailable for revitalizing the energy storage device.
Image courtesy of Dr. Musthafa’s lab, IISER, Pune