(Press-News.org) Consumers aren't embracing electric cars and trucks, partly due to the dearth of charging stations required to keep them moving. Even the conservation-minded are hesitant to go electric in some states because, studies show, if fossil fuels generate the electricity, the car is no greener than one powered with an efficient gasoline.
Charging cars by solar cell would appear to be the answer. But most cells fail to meet the power requirements needed to directly charge lithium-ion batteries used in today's all-electric and plug-in hybrid electric vehicles.
Researchers at Case Western Reserve University, however, have wired four perovskite solar cells in series to enhance the voltage and directly photo-charged lithium batteries with 7.8 percent efficiency--the most efficient reported to date, the researchers believe.
The research, published in the Aug. 27 issue of Nature Communications, holds promise for cleaner transportation, home power sources and more.
"We found the right match between the solar cell and battery," said Liming Dai, the Kent Hale Smith Professor of macromolecular science and engineering and leader of the research. "Others have used polymer solar cells to charge lithium batteries, but not with this efficiency."
In fact, the researchers say their overall photoelectric conversion and storage outperformed all other reported couplings of a photo-charging component with lithium-ion batteries, flow batteries or super-capacitors.
Perovskite solar cells have active materials with a crystalline structure identical to the mineral perovskite and are considered a promising new design for capturing solar energy. Compared to silicon-based cells, they convert a broader spectrum of sunlight into electricity.
In short order, they have matched the energy conversion of silicon cells, and researchers around the world are pursuing further advances.
Dai's lab made multilayer solar cells, which increases their energy density, performance and stability. Testing showed that, as desired, the three layers convert into a single perovskite film.
By wiring four lab-sized cells, about 0.1 centimeter square each, in series, the researchers further increased the open circuit voltage. The solar-to-electric power conversion efficiency was 12.65 percent.
To charge button-sized lithium-ion batteries, they used a lithium-ion-phosphate cathode and a lithium-titanium-oxide anode. The photoelectric conversion and storage efficiency was 7.8 percent. Through 10 photo-charge/galvanostatic (steady current) discharge cycles lasting nearly 18 hours, the technology maintained almost identical discharge/charge curves over all cycles, showing high cycling stability and compatibility of the components.
"We envision, in the not too distant future, this is a system that you could have at home to refuel your car and, eventually, because perovskite solar cells can be made as a flexible film, they would be on the car itself," said Jiantie Xu, who, with Yonghua Chen, is an equally contributing first author of the study. Both are macromolecular science and engineering research associates in Case School of Engineering.
The researchers are developing small-scale prototypes and working to further improve the perovskite cell's stability and optimize the system.
INFORMATION:
New research published in Acta Obstetricia et Gynecologica Scandinavica, a journal of the Nordic Federation of Societies of Obstetrics and Gynecology, found that pregnant women in Sweden had inadequate levels of iodine in their diets. Proper iodine nutrition is necessary for neurological development of the fetus.
Iodine is an element that is involved in the production of thyroid hormones. Pregnant and breastfeeding women need about 50% more iodine in the diets, and WHO recommends a total daily iodine intake of 250 μg/d for pregnant and lactating women. Medical evidence ...
Probiotics show no benefit for preventing or eliminating gastrointestinal colonization with drug-resistant organisms in patients in the intensive care unit compared to standard care, according to new research published online today in Infection Control & Hospital Epidemiology, the journal of the Society for Healthcare Epidemiology of America.
"Our research suggests that probiotics do not help prevent gastrointestinal colonization with multidrug-resistant organisms in critically ill patients," said Jennie H. Kwon, DO, lead author of the study.
This prospective, randomized ...
August 27, 2015 - Do you have problems with dry eyes? If so, you're not alone--it's one of the most common reasons for patient visits to eye care professionals. Recent years have seen significant progress in management of patients with dry eyes, according to the September special issue of Optometry and Vision Science, official journal of the American Academy of Optometry. The journal is published by Wolters Kluwer.
"There has been a growing interest among clinicians and patients on treatment and management and origins of the signs and symptoms of dry eye," comments Anthony ...
This news release is available in French.
Not even close to every person who faces challenges or lives with severe depression commits suicide. Some people are more vulnerable than others.
A series of studies has shown that the way in which a person makes decisions is among the main factors that determines whether that person is protected from or vulnerable to suicide. High-risk decision-making was prevalent among many parents of individuals who committed suicide, which may serve to explain its apparent "inheritability".
Dr. Fabrice Jollant, Assistant Professor ...
While most primary care physicians responding to a survey taken in late 2014 and early 2015 expressed confidence in their ability to identify potential cases of Ebola and communicate Ebola risks to their patients, only 50 to 70 percent of them gave answers that fit with CDC guidelines when asked how they would care for hypothetical patients who might have been exposed to Ebola. In addition, those who were least likely to encounter an Ebola patient - based on their location and characteristics of their patients - were most likely to choose overly intense management of patients ...
Knut, the famous polar bear of the Berlin Zoological Garden (Germany) died of encephalitis, as diagnosed soon after his death. However, the cause of his disease has remained elusive until now. A team of scientists from the German Center for Neurodegenerative Diseases (DZNE), the Leibniz Institute for Zoo and Wildlife Research (IZW) and the Charite - Universitaetsmedizin Berlin has now solved the case: The polar bear suffered from an autoimmune disease of the brain. This non-infectious illness is called "anti-NMDA receptor encephalitis", with symptoms in human patients similar ...
A team of international scientists, led by astronomers from Cardiff University's School of Physics and Astronomy, has shown for the first time that galaxies can change their structure over the course of their lifetime.
By observing the sky as it is today, and peering back in time using the Hubble and Herschel telescopes, the team have shown that a large proportion of galaxies have undergone a major 'metamorphosis' since they were initially formed after the Big Bang.
By providing the first direct evidence of the extent of this transformation, the team hope to shed light ...
Subject, verb, object: a triad that in spoken discourse (as well as written) can be arranged in different positions (six, in principle) although in the overwhelming majority of world languages, 86%, they occur in two forms: SVO ("Johnny eats the banana") and SOV ("Johnny the banana eats"). In particular, the latter is the most common and scientific literature supports the hypothesis that it is a basic form, perhaps the first to emerge when a new language or communication system is born. To back this up is the fact that over the course of history many languages have passed ...
Eating foods rich in amino acids could be as good for your heart as stopping smoking or getting more exercise - according to new research from the University of East Anglia (UEA).
A new study published today reveals that people who eat high levels of certain amino acids found in meat and plant-based protein have lower blood pressure and arterial stiffness.
And the magnitude of the association is similar to those previously reported for lifestyle risk factors including salt intake, physical activity, alcohol consumption and smoking.
Researchers investigated the effect ...
Cells continually form membrane vesicles that are released into the cell. If this vital process is disturbed, nerve cells, for example, cannot communicate with each other. The protein molecule dynamin is essential for the regulated formation and release of many vesicles. Scientists of the Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC) and the Institute for Biophysical Chemistry of Hannover Medical School (MHH), together with researchers from the Freie Universität Berlin and the Leibniz-Institut für Molekulare Pharmakologie (FMP), ...
