Photo-enhanced rechargeable batteries both convert and store solar energy

As the climate crisis deepens, scientists are racing to find solutions to common clean energy problems, including solar energy storage. Solar energy is considered the most promising renewable energy source, but it presents challenges that prevent it from being widely adopted. Solar cells, which harvest and convert solar energy into electrical energy, cannot store energy long-term, and separate battery storage systems are impractical and expensive.

In order to solve this problem, researchers are trying to find ways to combine the power conversion and storage capacity needs of solar energy into a single device.

Previous attempts to simplify solar energy conversion and storage combined two different components into a complicated device architecture, which was ultimately inefficient, expensive, and cumbersome. But significant progress has been made in combining these elements into a single device, which shares elements and greatly reduces the problems of previous designs.

“The amount of solar energy received at the Earth’s surface can reach 100,000 terawatt hours, which fully meets the demand of the annual global power consumption of 16 terawatts,” said the author of the article Hairong Xue, an assistant professor at the National Institute of Materials Science (NIMS) in Japan.

“However, like wind power, solar power is intermittent due to fluctuations in isolation. To balance supply and demand, converted solar power must be stored in other energy storage devices. Therefore, it is imperative to integrate appropriate energy storage technologies into solar cells, enabling efficient use of solar energy and supplying the generated electricity when needed.

In an article published in Nano Research Energy, NIMS researchers summarized recent advances in the use of six different types of photo-enhanced rechargeable metal batteries – lithium-ion, zinc-ion, lithium-sulfur, lithium-iodine, zinc-iodine, lithium-oxygen cells, zinc-oxygen and lithium-carbon dioxide. The paper details the advantages and disadvantages of each type of battery and how it can be applied to converting and storing solar energy into electricity.

This technology is still in its infancy and there is still a lot to do. Researchers hope to take the next steps towards improving solar energy storage using photo-enhanced rechargeable metal batteries.

“There is a need to explore more suitable electrode materials and optimize the device structure of batteries,” Xue said. “For practical applications, stability and security issues need to be addressed and improved. Although the development of photo-enhanced rechargeable metal batteries is quite rapid, most studies are still in the early stages of laboratory testing. By addressing some critical challenges involving working mechanism, electrode materials, and battery structure design, the goal is to demonstrate viable uses of photo-enhanced rechargeable batteries in electronic and optoelectronic devices.

The researchers also hope to explore how this technology could be applied to other types of energy conversion and storage systems.

Jack C. Nugent