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Thin Molecular Layer that makes Batteries more Reliable

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Researchers at Penn State University’s Battery and Energy Storage Technology Center are looking to come up with better automobile chargers that are more reliable and charge quicker.

They are experimenting with a thin layer of electrochemically active molecules that are self-assembling to make better batteries.

“The lithium metal battery is the next generation of battery after the lithium ion battery,” explained Donghai Wang, researcher at Penn State University’s Battery and Energy Storage Technology Center and a Mechanical, Chemical engineering professor. “It uses a lithium anode and has higher energy density but has problems with dendritic growth, low efficiency, and low cycle life.”

The researchers are working with a self-assembling monolayer to solve these problems. Because it is electrochemically active, it breaks down into its various components to protect the lithium anode’s surface.

The battery in question has a lithium anode as well as a lithium metal oxide cathode and an electrolyte with materials that conduct lithium-ion. It also has the thin film layer on the outside that prevents the battery from growing lithium crystal spikes when it is charged too quickly or when the temperature is too cool. The spikes also cause the battery to short and cut short its longevity.

Says Professor Wang: “The key is to tune the molecular chemistry to self-assemble on the surface. The monolayer will provide a good solid electrolyte interface when charging and protect the lithium anode.”

The monolayer is first deposited on a thin layer of copper so that when charged, the lithium contacts the monolayer and breaks down into an interfacial layer that is stable.

Some lithium deposits on the copper with the other layer and the decomposed part of the first layer is restored on top of the lithium where it protects it and prevents the formation of lithium dendrites.

Researchers say that the technology can boost battery storage capacity and enable batteries to be charged more times in its lifetime. It cannot be charged more than a few hundred times at this point.

“The key is that this technology shows an ability to form a layer when needed on time and decompose and spontaneously reform so it will stay on the copper and also cover the surface of the lithium,” explained Wang. “Eventually it could be used for drones, cars, or some very small batteries used for underwater applications at low temperatures.”

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Ride Sharing Services Associated With Binge Drinking

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Ride-sharing companies such as Lyft and Uber are uniquely positioned to reduce fatalities and deaths from drunk driving and also, according to a recent study, they are linked to increased binge drinking.

To date, much of the research carried out on drunk driving and ride-sharing focuses on how services like Uber could contribute to a decrease in DWIs, fatalities, and accidents, the researchers noted.

‘’There’s fairly strong evidence that this expanded supply of transportation is allowing people to do less driving while drunk,’’ co-author Jeffrey McCullough said, health management and policy associate professor of Michigan School of Public Health University. ‘’But at the same time, we found that it is making it easier for people to engage in alcohol consumption particularly binge drinking, which is the worst kind of drinking.’’

McCullough and collaborators used press releases from Uber to indicate when the service entered the market. They contrasted this data against what they knew about population density and alcohol consumption according to the Behavioral Risk Factor Surveillance Systems Annual Survey, an extensive US survey on residents about preventive services use, chronic health conditions, and their risk behaviors.

Using 113 urban markets data collected between 2010 and 2016, the researchers specifically looked at those who confessed that in the preceding 30 days they had drunk alcohol and the ones that confessed to binge drinking (approximately 5 drinks for males and 4 drinks for females at once) in the same period.

Researchers didn’t find a connection between Uber’s entrance into the market and generally modest alcohol consumption frequency. Still, they witnessed that in high-density markets, binge drinking rose by 4% after Uber’s came into the market.

”Clearly, there are health benefits to reducing drunk driving, but we are also seeing an increase in binge drinking,” said McCullough. ”It’s not that we should stop ride-hailing services. They do create value. But the study suggests we should be thinking about other public health risks related to alcohol consumption as transportation technology changes.’’

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China Unveils Superconducting Train

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Chinese researchers have made public a new maglev train prototype they developed. Running on high-temperature technology, the high-speed train will run on liquid nitrogen which is much cheaper than liquid helium.

Chinese officials and press received the prototype last week in Chengdu. Southwest Jiatong University hosted the unveiling and witnessed test runs.

The prototype has leveraged several new technologies; such as a low-resistance locomotive shape, a light-weight carbon fiber body, and a superconducting maglev with a capacity for both high-temperature and large load.

Traditional railway trains run on wheels but maglev (also referred to as magnetic levitation) trains are propelled above a guidance track. The Southwest Jiatong University is the birthplace of the superconducting maglev technology.

From the 1980s, the school has worked to advance technological innovation and theoretical research. The university partnered with China Railway Group Limited, China Railway Rolling Stock Corporation and other companies and institutions in 2020 to begin on the prototype’s manufacture. Other than that, they needed to manufacture the test line and build the train’s transit system.

Wu Zili, a senior engineer in SWJTU, was interviewed by the South China Morning Post. He mentioned the train’s systems achieved superconductivity at about one-fiftieth of what liquid helium systems cost. He explained that ordinary superconductors required -269 degrees Celsius while high-temperature superconductors could only work with liquid nitrogen at -196 degrees Celsius.

The engineer added that the train had a self-maglev feature. The train was capable of remaining suspended without extra energy. The train is intended to move at a record speed of 385mph (800km/h.

Future editions of the train are expected to rise to a speed of 500mph (800km/h) because of low vacuum tunnel technology. Trials for an even better maglev prototype were running last year at Shanghai Tonji University.

SJTU is working on other innovations besides the maglev train. An urban rail vehicle running on wireless power supply is also in the works.

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A Composite Material Promises to make Electric Vehicles even Better

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A team of scientists based at Oak Ridge National Laboratory is working on a composite that gives copper wires an enhanced capacity for electrical current, making them more efficient and power dense.

The new material would be used to make Electrical Vehicle traction motors more efficient and power dense.

The researchers want to eliminate some of the challenges that keep Electrical Vehicles from being adopted more widely. Some of these barriers are higher costs of ownership, performance, and the longevity of some of the components, like power electronics and electric motors.

The composite material works with any component that has copper. This includes bus bars, Electric vehicle traction inverters, and charging systems.

ORNL researchers deposited carbon nanotubes on the surface of flat copper substrate to create a composite material that handles current better and whose mechanical properties beat copper. This material is lighter than copper and performs better.

Carbon nanotubes (CNTs) being used to make a copper matrix better is nothing new. CNTs lightweight, strength, and conductivity have made them a favorite material for such attempts before. But previous experiments have created in materials with shorter material strength and poor scalability, or poor performance when longer.

The team at ORNL opted to deposit CNTs using the electro spinning method which is commercially viable and hence more scalable to create fibers using a jet of liquid speeding through an electric field.

With this technique, you enjoy a higher ability to control the orientation and structure of the deposited material, according to ORNL post doctoral researcher Kai Li who is based in the Chemical Sciences Division.

Scientists were this time able to orient the CNTs in one direction for improved electrical flow.

The team of scientists used a technique of vacuum coating called magnetron sputtering during which they add thin copper films on top of copper tapes coated with CNT. The copper samples yielded a super conductive Cu-CNT network when they were annealed inside a vacuum furnace.

They executed this by creating a solid and uniform layer of copper and allowed copper to be diffused into the CNT matrix.

ORNL scientists created a copper-carbon nanotube composite using this technique. The composite measured 10 centimeters in length and 4 cm in width and exhibited excellent material properties.

The material has microstructural properties and was analyzed at the ORNL Center for Nanophase Materials which is a user facility with the US Department of Energy Office of Sciences. The researchers established that the composite had a current capacity that was 14% greater and mechanical properties 20% greater than pure copper.

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