 energy state to a lower one, while doing work in an external circuit. The photobattery has a mechanism similar to an ordinary battery except that it need not be supplied current or plugged into the wall to be charged electrically, but can be charged photoelectrically under the sun. The active material in this new battery is the lead-free perovskite which, when put under light, absorbs a photon and generates a pair of charges, known as an electron and a hole. The team conducted chrono-amperometry experiments under light and in dark to analyze the increase in charging current caused by the light, and recorded a photo-conversion efficiency rate of 0.428% on photocharging the battery after the first discharge. The next step of the team is to experiment with different materials for better performance and efficiency, so that the photobattery can be commercialized in the market.
"At present, we plug all our appliances into the wall to charge them. With further development in this field of photobatteries, we might not have to plug them in at all in the future," said Prof. Halpert. "We might be able to harvest solar energy and use it to fulfill the power requirements of any devices with modest power needs. Our work is one of the initial steps taken in this field, and, of course, a lot of improvements will be needed to achieve better performance, but we are confident that we can improve its stability and average efficiency with further refinement."
This photobattery can serve as the built-in battery for devices such as smartphones or tablets, and even remote energy storage applications, which can be made easy with these photobatteries for they are lightweight and portable. It should also help lower production cost when compared to a system consisting of a solar cell plus an external battery since only the battery part is required.
This study was recently published in the scientific journal Nano Letters.
More information: Neha Tewari et al, Photorechargeable Lead-Free Perovskite Lithium-Ion Batteries Using Hexagonal Cs3Bi2I9 Nanosheets, Nano Letters (2021). DOI: 10.1021/acs.nanolett.1c01000
Journal information: Nano Letters
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