Because “nomophobia” is a real thing (fear of being out of mobile contact), having battery power is of the utmost importance for some people. But sometimes, you do run out of power bank juice and you may be in a place or situation where plugging into the wall socket is not possible. So for times like these, wouldn’t it be great if you could use natural elements to power up your device or even your battery? Researchers in Japan have come up with a prototype of a lithium ion battery that can recharge simply by using available sunlight.

The group, led by Mitsunobu Sato, president of Kogakuin University and professor at the Department of Applied Physics, School of Advanced Engineering of the university, had previously created a translucent Li-ion rechargeable battery back in 2013 which they presented as a thesis. While Li-ion rechargeable batteries were already a thing, they used the same materials, but used oxides to make the positive and negative electrodes as thin as 80nm and 90nm to give out a high light transmittance.

This time around, they were able to make a prototype of the solar powered rechargeable battery. And up next, they want to present a “smart window” which will serve as a large-area rechargeable battery and which also will be able to receive sunlight because it is a photovoltaic cell. It will lower light transmittance since it will be pigmented. At a recently concluded trade innovation show in Japan, they showcased an experiment that showed that the optical charge and discharge of the battery are repeated five times when using near-ultravioet light. That is just about 1/10 that of sunlight.

If this comes to fruition and will be picked up by any of the OEMs, they have the chance of creating a semi solar powered smartphone. This might solve some of the problems facing people whose batteries are always in need of a charge.

VIA: Nikkei Technology