Science snapshots from Berkeley Lab

Berkeley Lab Pushes Its Energy-Saving Windows into the Market

By Julie Chao

Windows make up 7% of the envelope area of a home but can account for 47% of the envelope heat loss. High-performance windows thus represent a significant opportunity for consumers to be more comfortable and save money - and help reduce energy demand and greenhouse gas emissions while doing so.

Now Berkeley Lab is teaming up with the Northwest Energy Efficiency Alliance (NEEA), the Pacific Northwest National Laboratory (PNNL), and other organizations to create the Partnership for Advanced Window Solutions (PAWS), with the aim of accelerating nationwide adoption of highly efficient windows, storm windows and shading systems.

"Berkeley Lab's core mission is more on the research side, but of course, we're always looking at bringing the technology to the market," said Berkeley Lab windows researcher Robert Hart. "In this case, PAWS is going to build on the R&D basics that we have been working on for 40 years, but it's going to bring in a lot of new partners who are more market-oriented."

The decades of windows research at Berkeley Lab sponsored by the Department of Energy's Buildings Technologies Office and the California Energy Commission has led to low-emissivity (or low-E) coatings now found in more than 80% of windows sold, and even more efficient products such as thin-triple glazing which has just been brought to market by multiple major U.S. manufacturers. Now the Berkeley Lab team is working with PAWS and PNNL to conduct field demonstrations of high-performance windows and window attachments and support manufacturers and utility companies with new analysis, tools, and ratings.

"Buying new windows for a home can be expensive, but if you're going to be replacing them anyway, the incremental cost of going for a highly insulating window is not that much," said Stephen Selkowitz, now a retired affiliate in Berkeley Lab's Energy Technologies Area (ETA). "In addition to saving energy, these high-performance windows add comfort, have health benefits such as reducing the risk of condensation, and add resilience to buildings in the face of climate extremes."

Microbial Fingerprints for Cities

By Ashleigh Papp

Vibrant cities around the world are made up of a unique blend of cultures, languages, cuisines, and - as scientists recently revealed - microbes.

Nearly 1,000 scientists from around the world, including three from Berkeley Lab, collected and analyzed microbial samples from public transit stations across 60 global cities. They probed ticket kiosks, benches, and rails to see what tiny organisms like bacteria, viruses, and archaea were in residence. The team found that in most cities, the same four bacteria phyla - Proteobacteria, Actinobacteria, Firmicutes, and Bacteroidota - are most abundant, but more interestingly, they discovered that each location also has its own distinct set of microbes.

Nikos Kyrpides, head of the DOE Joint Genome Institute (JGI) Microbiome Data Science group, along with Russell Neches, a postdoctoral researcher, and David Paez-Espino, a research scientist, used an extensive JGI database to investigate viruses detected in the samples.

The JGI scientists took the nearly 5,000 viral genome samples collected by the larger consortium of scientists involved in this work, known as the International Metagenomics and Metadesign of Subways and Urban Biomes, or MetaSUB, and compared them to the database. Neches and Kyrpides then set out to map the diversity and global distribution of the viruses.

"The integration of all these data in a single database is a key resource for the research community which provides a reference point for comparing viruses identified from new samples," Kyrpides said.

In addition to mapping microbial signatures, scientists discovered over 10,000 new viruses and bacteria, hinting at the vast world of microbes that is yet to be understood.

Public health officials can now use these microbial maps to keep track of virus and bacteria levels over time. "It's like a census," Neches said. "This can inform on where public health resources can best be allocated to benefit all of us."

Read the Cornell Press Release HERE

Scientists Discover How Oxygen Loss Saps a Lithium-Ion Battery's Voltage

Adapted from a SLAC news release by Glennda Chui

Lithium-ion batteries work like a rocking chair, moving lithium ions back and forth between two electrodes that temporarily store charge. Ideally, those ions are the only things moving in and out of the billions of nanoparticles that make up each electrode.

But researchers have known for some time that oxygen atoms leak out of the particles as lithium moves back and forth. The details have been hard to pin down because the signals from these leaks are too small to measure directly.

Now, in a study published in Nature Energy, a research team co-led by SLAC National Accelerator Laboratory, Stanford University, and Berkeley Lab has measured this process with unprecedented detail, showing how the holes, or vacancies, left by escaping oxygen atoms change the electrode's structure and chemistry and gradually reduce how much energy it can store.

Using COSMIC, a multipurpose X-ray instrument at Berkeley Lab's Advanced Light Source (ALS), the research team scanned across samples of electrode nanoparticles, making high-res images and probing the chemical makeup of each tiny spot. This information was combined with a computational technique called ptychography to reveal nanoscale details, measured in billionths of a meter.

At SLAC's Stanford Synchrotron Lightsource, the team shot X-rays through entire electrodes to confirm that what they were seeing at the nanoscale level was also true at a much larger scale.

Comparing the experimental results with computer models of how oxygen loss might occur, the team concluded that an initial burst of oxygen escapes from the surfaces of particles, followed by a very slow trickle from the interior. Where nanoparticles glommed together to form larger clumps, those near the center of the clump lost less oxygen than those near the surface.

The results contradict some of the assumptions scientists had made about this process and could suggest new ways of engineering electrodes to prevent it.

"Previously, researchers were not able to access the length scales needed to study oxygen release in batteries from the primary particle to the electrode level. COSMIC's ability to achieve few-nanometer spatial resolution with chemical specifity across a wide field allowed us, for the first time, to study the influence of microstructure on this phenomenon." said co-senior author David Shapiro, who is the lead scientist for COSMIC's microscopy experiments. Shapiro also leads the ALS Microscopy Program.

Scientists Uncover a Different Facet of Fuel-Cell Chemistry

By Lori Tamura

Solid oxide fuel cells (SOFCs) are a promising technology for cleanly converting chemical energy to electrical energy. But their efficiency depends on the rate at which solids and gases interact at the devices' electrode surfaces. Thus, to explore ways to improve SOFC efficiency, an international team led by researchers from Berkeley Lab studied a model electrode material in a new way - by exposing a different facet of its crystal structure to oxygen gas at operating pressures and temperatures.

"We began by asking questions like, could different reaction rates be achieved from the same material, just by changing which surface the oxygen reacts with?" said Lane Martin, a faculty scientist in Berkeley Lab's Materials Sciences Division. "We wanted to examine how the atomic configuration at specific surfaces of these materials makes a difference when it comes to reacting with the oxygen gas."

Thin films of a common SOFC cathode material, lanthanum strontium cobalt ferrite (LSCF), were synthesized to expose a surface that was oriented along a diagonal crystallographic plane. Electrochemical measurements on this atypical surface yielded oxygen reaction rates up to three times faster than those measured on the usual horizontal plane.

To better understand the mechanisms underlying this improvement, the researchers used Berkeley Lab's Advanced Light Source (ALS) to probe the "new" surface at high temperatures and in varying pressures of oxygen. The results revealed that different crystallographic planes stabilize different surface chemistries, even though the chemistry in the bulk of the films is unchanged.

"Exposing different surfaces to air can lead to completely different structures, chemistries, and defect concentrations to a point where these surfaces almost look and act like different materials," said Abel Fernandez, a graduate student in Materials Science and Engineering at UC Berkeley and co-first author of the study. "Taking our results into consideration can allow manufacturers a relatively simple way to enhance the reactivity of LSCF-based cathodes without the groundwork typically necessary for utilizing new materials chemistries."