It's now fairly common to hear about batteries being used to store power generated by solar cells. A group of Indian scientists, however, have eliminated the middleman. They've created a battery that incorporates a titanium nitride-based photoanode in place of a conventional anode, allowing the battery to charge itself using solar or artificial light.
The battery was created by a team led by Dr. Musthafa Ottakam Thotiyl, of the Indian Institute of Science Education and Research.
According to the researchers, it's able to fully charge within 30 seconds using normal indoor lighting. It's subsequently able to discharge enough of a current to illuminate an LED or run a small fan, and lasts for over 100 charge/discharge cycles.
Additionally, titanium nitride is claimed to be more stable than traditional anode materials, making the battery less likely to overheat and catch fire. In its present form, however, it lacks the capacity needed to power electronic devices such as smartphones.
The "photo battery" is described in a paper recently published in The Journal of Physical Chemistry C, and is demonstrated in the video below.
Source: American Chemical Society