Imagine living in a world where sunlight is our dominant source of energy.
You never have to think about charging your mobile device or smartphone. You never have to worry about buying fuel for your vehicle. You never have to pay for energy for your home or any of the appliances inside. And none of the energy used has any adverse impact on the environment.
It may sound like science fiction, but that world is not that far off thanks to some innovative researchers from Case Western Reserve University.
Led by Liming Dai, Kent Hale Smith professor of macromolecular science and engineering, CWRU researchers have found a way to increase the efficacy of photoelectric solar cells while enhancing the application across a wide spectrum of industries. The new system could have an almost immediate application for the lithium-ion batteries that power electric vehicles.
“This type of solar cell has a very high efficiency,” says Dai. “The new material not only has a higher chargeability, it also allows the charge to live in the solar cell for a longer time.”
Dai’s team wired four perovskite solar cells — the fastest-advancing solar cells to date — in a series to enhance voltage, using the module to directly charge lithium ion batteries with 7.8 percent efficiency. That’s for the entire system, starting from the import of sunlight energy to the output of electricity from the battery.
“For a polymer solar cell, 10 percent efficiency is very high,” says Dai. “With this cell, we can now achieve about 20 percent efficiency from the solar cell.”
Perovskite solar cells possess materials with a crystalline structure that capture and hold solar energy at a higher efficiency than other types of solar cells. They also convert a broader spectrum of sunlight into electricity than polymer-based solar cells.
To increase energy density, performance and stability, Dai’s team created a multilayered solar cell, converting three layers into a single film. By wiring four lab-sized cells together in series, the team was able to increase open-circuit voltage to further enhance efficacy.
Creating a solar cell film also increased the utility and application of the whole system. For instance, the new technology has obvious applications for electric vehicles, which could use the film on the vehicle’s skin to help keep its primary lithium-ion battery charged.
While electric vehicles are becoming increasing popular across the country, growth of the market has always been hampered by something called range anxiety, which is directly linked to a lack of available charging stations and a relatively short cruising range.
Some manufacturers have been able to increase this range to more than 200 miles, but most are still below a threshold of 100 miles. And though there have been some advancements in the time it takes to recharge these vehicles, most are still measured in hours rather than minutes.
That means a typical electric vehicle spends more time recharging than actually driving. And if you’re recharging the vehicle from a fossil fuel source, its eco-friendliness is likely much diminished.
The perovskite film solar cell offers an electricity fuel source that is not fossil fuel based and uses the most abundant form of energy on our planet. Indeed, this new film may also find applications on buildings to create home recharging stations or to generate electricity for an
entire house.
There are still a few obstacles to overcome in engineering, such as making the system more stable and resistant to environment factors including heat, cold and moisture. But Dai’s team is working hard.
Needless to say, the auto industry has already showed interest. Although Dai refused to indicate which automakers may be interested, the technology may soon be found on tomorrow’s vehicles.
And it just may be game-changer for all of our energy needs in the very near future.