Researchers Take Step Toward Lithium-sulfur Batteries
A fevered search for the next great high-energy, rechargeable battery technology is on. Scientists are reporting they have overcome key obstacles toward making lithium-sulfur (Li-S) batteries, which have the potential to leave today’s lithium-ion technology in the dust. Their study appears in the ACS journal Nano Letters.
Xingcheng Xiao, Weidong Zhou, Mei Cai and their colleagues point out that the capabilities of lithium-ion batteries, which power many of our consumer electronics, as well as electric vehicles, have largely plateaued. Scientists have been pursuing a number of new battery technologies to topple today’s standard.
In 2015, American consumers will finally be able to purchase fuel cell cars from Toyota and other manufacturers. Although touted as zero-emissions vehicles, most of the cars will run on hydrogen made from natural gas, a fossil fuel that contributes to global warming.
Now, scientists at Stanford Univ. have developed a low-cost, emissions-free device that uses an ordinary AAA battery to produce hydrogen by water electrolysis. The battery sends an electric current through two electrodes that split liquid water into hydrogen and oxygen gas. Unlike other water splitters that use precious-metal catalysts, the electrodes in the Stanford device are made of inexpensive and abundant nickel and iron.
A system proposed by researchers at MIT recycles materials from discarded car batteries — a potential source of lead pollution — into new, long-lasting solar panels that provide emissions-free power.
The system is described in a paper in the journal Energy and Environmental Science, co-authored by Profs. Angela Belcher and Paula Hammond, graduate student Po-Yen Chen and three others. It is based on a recent development in solar cells that makes use of a compound called perovskite — specifically, organolead halide perovskite — a technology that has rapidly progressed from initial experiments to a point where its efficiency is nearly competitive with that of other types of solar cells.
Cornell Univ. chemical engineers have achieved a breakthrough in the race for safer, longer-lasting batteries to power the world’s automobiles, cell phones, computers and autonomous robots.
Adding certain halide salts to liquid electrolytes spontaneously creates nanostructured surface coatings on a lithium battery anode that hinder the development of detrimental dendritic structures that grow within the battery cell. The discovery opens the way potentially to extend the daily cycle life of a rechargeable lithium battery by up to a factor of 10.
In the future, working up a sweat by exercising may not only be good for your health, but it could also power your small electronic devices. Researchers are reporting today that they have designed a sensor in the form of a temporary tattoo that can both monitor a person’s progress during exercise and produce power from their perspiration. The team described the approach in one of nearly 12,000 presentations at the 248th National Meeting & Exposition of the American Chemical Society (ACS).
The device works by detecting and responding to lactate, which is naturally present in sweat. “Lactate is a very important indicator of how you are doing during exercise,” said Wenzhao Jia.
The energy world is not keeping up with Elon Musk, so he’s trying to take matters into his own hands. Musk, chairman of the solar installer SolarCity, has announced that the company would acquire a solar panel maker and build factories “an order of magnitude” bigger than the plants that currently churn out panels. “If we don’t do this we felt there was a risk of not being able to have the solar panels we need to expand the business in the long term,” Musk said in a conference call.
Musk is also a founder and the CEO of the electric vehicle maker Tesla Motors, which is planning what it calls a “gigafactory” to supply batteries for its cars.In both cases, Musk’s goal is to make sure that the components critical to his vision of the future — electric cars and solar energy — are available and cheap enough to beat fossil fuels.
Researchers at UC Riverside Bourns College of Engineering have developed a three-dimensional, silicon-decorated, cone-shaped carbon-nanotube cluster architecture for lithium ion battery anodes that could enable charging of portable electronics in 10 minutes, instead of hours.
Lithium ion batteries are the rechargeable battery of choice for portable electronic devices and electric vehicles. But, they present problems. Batteries in electric vehicles are responsible for a significant portion of the vehicle mass. And the size of batteries in portable electronics limits the trend of down-sizing.
New observations by researchers at MIT have revealed the inner workings of a type of electrode widely used in lithium-ion batteries. The new findings explain the unexpectedly high power and long cycle life of such batteries, the researchers say.
The findings appear in a paper in the journal Nano Letters co-authored by MIT postdoc Jun Jie Niu, research scientist Akihiro Kushima, professors Yet-Ming Chiang and Ju Li and three others.
Vast amounts of excess heat are generated by industrial processes and by electric power plants; researchers around the world have spent decades seeking ways to harness some of this wasted energy. Most such efforts have focused on thermoelectric devices, solid-state materials that can produce electricity from a temperature gradient, but the efficiency of such devices is limited by the availability of materials.
Now, researchers at MIT and Stanford Univ. have found a new alternative for low-temperature waste-heat conversion into electricity — that is, in cases where temperature differences are less than 100 C.
A new prototype electric car battery could take you a lot farther and last a lot longer. Jeff Pyun and his team at the Univ. of Arizona are using modified sulfur, a common industrial waste product, to boost the charge capacity and extend the life of these batteries.
As news reports of lithium-ion battery (LIB) fires in Boeing Dreamliner planes and Tesla electric cars remind us, these batteries — which are in everyday portable devices, like tablets and smartphones — have their downsides. Now, scientists have designed a safer kind of lithium battery component that is far less likely to catch fire and still promises effective performance. They report their approach in the Journal of the American Chemical Society.
Lynden Archer, Geoffrey Coates and colleagues at Cornell Univ. explain that the danger of LIBs originates with their electrolytes, the substance that allows ions to flow between the electrodes of the battery. The electrolyte usually contains a flammable liquid. To minimize this fire hazard, some researchers are developing more stable, solid electrolytes.
‘Double-duty’ Electrolyte Key to Longer-lived Batteries
Researchers at the Department of Energy’s Oak Ridge National Laboratory have developed a new and unconventional battery chemistry aimed at producing batteries that last longer than previously thought possible.
In a study published in the Journal of the American Chemical Society, ORNL researchers challenged a long-held assumption that a battery’s three main components — the positive cathode, negative anode and ion-conducting electrolyte — can play only one role in the device. The electrolyte in the team’s new battery design has dual functions: it serves not only as an ion conductor but also as a cathode supplement. This cooperative chemistry, enabled by the use of an ORNL-developed solid electrolyte, delivers an extra boost to the battery’s capacity and extends the lifespan of the device.
Analysis Probes Charge Transfer in Battery Electrodes
The electrochemical reactions inside the porous electrodes of batteries and fuel cells have been described by theorists, but never measured directly. Now, a team at MIT has figured out a way to measure the fundamental charge transfer rate — finding some significant surprises.
The study found that the Butler-Volmer (BV) equation, usually used to describe reaction rates in electrodes, is inaccurate, especially at higher voltage levels. Instead, a different approach, called Marcus-Hush-Chidsey charge-transfer theory, provides more realistic results — revealing that the limiting step of these reactions is not what had been thought.
The new findings could help engineers design better electrodes to improve batteries’ rates of charging and discharging, and provide a better understanding of other electrochemical processes, such as how to control corrosion.
Saliva-powered micro-sized microbial fuel cells can produce minute amounts of energy sufficient to run on-chip applications, according to an international team of engineers.
Bruce Logan, Evan Pugh Professor and Kappe Professor of Environmental Engineering, Penn State, credits the idea to fellow researcher Justine Mink. “The idea was Justine’s because she was thinking about sensors for such things as glucose monitoring for diabetics and she wondered if a mini microbial fuel cell could be used,” Logan says. “There is a lot of organic stuff in saliva.”