Researchers have developed a new kind of semiconductor alloy capable of capturing the near-infrared light located on the edge of the visible light spectrum.

Easier to manufacture and at least 25 percent less costly than previous formulations, it’s believed to be the world’s most cost-effective material that can capture near-infrared light—and is compatible with the gallium arsenide semiconductors often used in concentrator photovoltaics.

Concentrator photovoltaics gather and focus sunlight onto small, high-efficiency solar cells made of gallium arsenide or germanium semiconductors. They’re on track to achieve efficiency rates of over 50 percent, while conventional flat-panel silicon solar cells top out in the mid-20s.

“Flat-panel silicon is basically maxed out in terms of efficiency,” says Rachel Goldman, a professor of materials science and engineering, as well as physics at the University of Michigan, whose lab developed the alloy. “The cost of silicon isn’t going down and efficiency isn’t going up. Concentrator photovoltaics could power the next generation.”

Varieties of concentrator photovoltaics exist today. They are made of three different semiconductor alloys layered together. Sprayed onto a semiconductor wafer in a process called molecular-beam epitaxy—a bit like spray painting with individual elements—each layer is only a few microns thick. The layers capture different parts of the solar spectrum; light that gets through one layer is captured by the next.

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In its first “Science for Solving Society’s Problems Challenge,” ECS partnered with the Bill & Melinda Gates Foundation to leverage the brainpower of the many scientists in electrochemistry and solid state science and technology that regularly attend ECS meetings. From this project, seven presentations were selected, with a total of $360,000 awarded to pursue research projects addressing world sanitation problems.

The powerPAD, a collaboration among Neus Sabaté, Juan Pablo Esquivel, and Erik Kjeang, was one of the projects selected to receive $50,000 in funding. Now, just over two years later, the researchers are discussing their findings and how their work has transformed over time.

“As originally proposed, the developed battery is completely made of organic materials such as cellulose, carbon electrodes, beeswax and organic redox species, and can be fabricated by affordable methods with low energy consumption,” Esquivel told ECS in an email. “After it’s used, the battery can be disposed of in an organic waste container or even discarded in the field, because it biodegrades by the action of microorganisms present in soils and water bodies. In the article we have shown that this biodegradable battery can substitute for a Li-ion coin cell battery to run a portable water monitoring device. The battery is activated upon the addition of a drop of the same water sample that is analyzed.”

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By: Erin Baker, University of Massachusetts Amherst

The U.S. Department of Energy spends US$3-$4 billion per year on applied energy research. These programs seek to provide clean and reliable energy and improve our energy security by driving innovation and helping companies bring new clean energy sources to market.

President Trump’s detailed budget request reportedly will ask Congress to cut funding for the Energy Department’s clean energy programs by almost 70 percent, from $2 billion this year to $636 million in 2018. Clean energy advocates and environmental groups strongly oppose such drastic cuts, but some reductions are likely. Where should DOE focus its limited funding to produce the greatest energy and environmental benefits?

My colleagues Laura Diaz Anadon of Cambridge University and Valentina Bosetti of Bocconi University and I recently reviewed 15 studies that asked this question. We found a number of clean energy technologies in electricity and transportation that will help us slow climate change by reducing greenhouse gas emissions, even at lower levels of investment.

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The development of the lithium-ion battery has helped enable the modern day electronics revolution, making possible everything from cellphones to laptops to electric vehicles and even grid-scale energy storage.

However, those batteries have limited lifespans. Battery expert Daniel P. Abraham is looking to address that.

“As your cellphone battery ages, you notice that you have to plug it in more often,” says Abraham, ECS member and scientist at Argonne National Laboratory. “Over a period of time, you are not able to store as much charge in the battery, and that is the process we call capacity fade.”

Abraham is a co-author of an open access paper recently published in the Journal of The Electrochemical Society, “Transition Metal Dissolution, Ion Migration, Electrocatalytic Reduction and Capacity Loss in Lithium-Ion Full Cells,” which addresses the question of why your battery doesn’t age well.

A majority of today’s electronic devices are powered by the lithium-ion battery. In order for the battery to store and release energy, lithium ions move back and forth between the positive and negative electrodes through an electrolyte.  In theory, the ions could travel back and forth an infinite number of times, resulting in a battery that lasts forever.

But that’s not what happens in the batteries that power your laptops and your electric vehicles. According to Abraham, unwanted side reactions often occur as ions move between the electrodes, resulting in batteries that lose capacity over time.

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By: Joshua D. Rhodes, University of Texas at Austin; Michael E. Webber, University of Texas at Austin; Thomas Deetjen, University of Texas at Austin, and Todd Davidson, University of Texas at Austin

U.S. Secretary of Energy Rick Perry in April requested a study to assess the effect of renewable energy policies on nuclear and coal-fired power plants.

Some energy analysts responded with confusion, as the subject has been extensively studied by grid operators and the Department of Energy’s own national labs. Others were more critical, saying the intent of the review is to favor the use of nuclear and coal over renewable sources.

So, are wind and solar killing coal and nuclear? Yes, but not by themselves and not for the reasons most people think. Are wind and solar killing grid reliability? No, not where the grid’s technology and regulations have been modernized. In those places, overall grid operation has improved, not worsened.

To understand why, we need to trace the path of electrons from the wall socket back to power generators and the markets and policies that dictate that flow. As energy scholars based in Texas – the national leader in wind – we’ve seen these dynamics play out over the past decade, including when Perry was governor.

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When a battery is used, electrically charged ions travel between electrodes, causing those electrodes to shrink and swell. For some time, researchers have wondered why the electrode materials – which are fairly brittle – don’t crack in the expansion and contraction styles.

Now, a team of researchers from MIT, led by ECS member Yet-Ming Chiang, may have found the answer to this mystery.

This from MIT:

While the electrode materials are normally crystalline, with all their atoms neatly arranged in a regular, repetitive array, when they undergo the charging or discharging process, they are transformed into a disordered, glass-like phase that can accommodate the strain of the dimensional changes.

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A newly created material may have the capacity to double the efficiency of solar cells.

Conventional solar cells are at most one-third efficient, a limit known to scientists as the Shockley-Queisser Limit. The new material, a crystalline structure that contains both inorganic materials (iodine and lead) and an organic material (methyl-ammonium), boosts the efficiency so that it can carry two-thirds of the energy from light without losing as much energy to heat.

In less technical terms, this material could double the amount of electricity produced without a significant cost increase, according to the new study in Science.

Enough solar energy reaches the earth to supply all of the planet’s energy needs multiple times over, but capturing that energy has been difficult—as of 2013, only about 1 percent of the world’s grid electricity was produced from solar panels.

The new material, called a hybrid perovskite, would create solar cells thinner than conventional silicon solar cells, and is also flexible, cheap, and easy to make, says Libai Huang, assistant professor of chemistry at Purdue University.

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A new mathematical model may help researchers design new materials for use in high-power batteries. According to the research team, the model could benefit chemists and materials scientists who typically rely on a trial and error method when developing new materials for batteries and capacitors.

“The potential here is that you could build batteries that last much longer and make them much smaller,” says Daniel Tartakovsky, co-author of the study. “If you could engineer a material with a far superior storage capacity than what we have today, then you could dramatically improve the performance of batteries.”

Demand for affordable, efficient energy storage continues to increase as more entities transition toward renewable energy. While there are many researchers working in the area of energy storage, the team behind this development is looking at the field in a new light.

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Image: Kathy F. Atkinson, University of Delaware

Fuel cells are an important technology for the nation’s energy portfolio, offering a cleaner, more efficient alternative to combustion engines that utilize fossil fuels.

However, a team of researchers from the University of Delaware point out that a major challenge in the commercialization of fuel cells is the durability of the membrane, which tends to develop cracks that short is life during operation.

A new article published in the Journal of The Electrochemical Society, “Self-Healing Composite Membrane for Proton Electrolyte Membrane Fuel Cell Applications,” aims to address the fuel cell membrane issue by developing a self-healing membrane, incorporating microcapsules prefilled with a Nafion solution.

“The microcapsules are designed to rupture when they encounter defects in the membrane and then release the prefilled Nafion solution to heal the defects in place,” says Liang Wang, past ECS member and co-author of the study.

Testing showed that the newly developed membrane and its self-healing functionality could greatly extend its useful life.

By: Joshua D. Rhodes, University of Texas at Austin

The electric grid is an amazing integrated system of machines spanning an entire continent. The National Academy of Engineering has called it one of the greatest engineering achievements of the 20th century.

But it is also expensive. By my analysis, the current (depreciated) value of the U.S. electric grid, comprising power plants, wires, transformers and poles, is roughly US$1.5 to $2 trillion. To replace it would cost almost $5 trillion.

That means the U.S. electric infrastructure, which already contains trillions of dollars of sunk capital, will soon need significant ongoing investment just to keep things the way they are. A power plant built during the rapid expansion of the power sector in the decades after World War II is now 40 years old or older, long paid off, and likely needs to be replaced. In fact, the American Society of Civil Engineers just gave the entire energy infrastructure a barely passing grade of D+.

The current administration has vowed to invest heavily in infrastructure, which raises a number of questions with regard to the electric system: What should the energy grid of the future look like? How do we achieve a low-carbon energy supply? What will it cost?

Infrastructure seems to be an issue that can gather support from both sides of the aisle. But to make good decisions on spending, we need first to understand the value of the existing grid.

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