A team of Ohio State University scientists have invented what they claim is the world’s first rechargeable solar battery. The team observed the issues in current methods for collecting and storing solar energy – particularly energy loss, which can run at around 20 percent during the process of transferring collected energy to a battery. They then developed a design that integrates a solar panel and battery components into one efficient and cost-effective device.
The research team has published its findings in the journal Nature Communications. In addition to the loss of energy in current systems, they also identified the issue of cost as a barrier to further uptake of solar in the community. While “on-the-grid” solar-powered homes can sell surplus energy to the grid and then buy power back when there is not enough solar available, off-grid homes have to invest in sometimes prohibitively expensive batteries. Grid power is also generally fossil-fuel sourced, which is a bone of contention for those wanting to run their grid-tied home on renewable energy.
The OSU rechargeable solar battery uses sunlight to create electrons, but differs wildly from regular solar panels in its design. The solar panel is made from a titanium mesh covered in titanium dioxide rods. The porous nature of the mesh allows air to circulate through the battery, which is an important part of the recharging process. Instead of the more common four electrodes, the design only utilizes three: the titanium mesh, a thin layer of porous carbon, and a lithium plate. There are layers of electrolytes between the three electrodes.
The Columbus Dispatch summarizes the rest of the process well: “(The) rods of titanium dioxide capture light. When the light hits the mesh solar panel, it creates electrons. Inside the battery, those electrons create energy by breaking down lithium peroxide into lithium ions and oxygen. The oxygen is released back into the air, through the mesh solar panel, and the lithium ions are stored in the battery for future energy.” Because the solar panel and the battery are one and the same unit, energy loss is minimal. The team also say the battery design should reduce manufacturing costs for solar-energy systems by 25 percent, and that the units should last as long as current products on the market. For now the design is not developed enough to power the average home, but the team is confident that they are on track for that breakthrough too.