A team of scientists at the University of Freiburg’s Cluster of Excellence Living, Adaptive, and Energy-Autonomous Materials Systems and the University of Ulm has developed a monolithically integrated photo battery consisting of an organic polymer-based battery and a multi-junction organic solar cell.

The battery presented by the team is the first monolithically integrated photo battery made of organic materials to achieve a discharge potential of 3.6 volts.

Monolithically integrated batteries that simultaneously generate, convert, and store energy in a single system could be used for this purpose. It is one of the first systems to supply electricity to small devices.

The researchers coupled the multi-junction solar cell with a so-called dual ion battery, which, in contrast to the cathodes of traditional lithium batteries, can be charged in high currents.

With measured illumination intensity and discharge rates, a photo battery constructed in this way was able to rapidly charge in less than 15 minutes at discharge capacities of up to 22 milliampere hours per gram (mAh g-1).

The researchers claimed that combined with the averaged discharge potential of 3.6 volts, the devices can provide an energy density of 69 milliwatt hours per gram (mWh g-1) and a power density of 95 milliwatts per gram (mW g-1).

The researchers have developed a photo-scale technique that produces organic solar cells with five active layers, achieving relatively high voltages of 4.2 volts.

Developing new, cleaner energy harvesting and storage technologies is necessary due to the significant challenge posed by the global growth in energy consumption and the corresponding carbon emissions. These ideally rely on renewable energy sources and have a minimized carbon footprint.

The need for small energy sources that run consumer electronics within the Internet of Things is constantly growing.

Earlier this year, a team of researchers from the Georgia Institute of Technology took a novel approach, utilizing aluminum foil to create solid-state batteries with increased energy density and stability compared to the widely used lithium-ion technology.

Researchers from the Monash University in Australia and the Royal Melbourne Institute of Technology have unveiled a lithium-sulfur battery design with a nanoporous polymer-coated lithium foil anode.