Lithium ion batteries are critical to many portable consumer electric devices, but they still do not have a high enough energy storage capacity for some applications, such as electric cars. Researchers and engineers are working to improve these batteries by changing the materials used. Using silicon as the anode has been promising, showing up to 10-fold higher capacity than the currently used graphite-based anode material. However, commercialization is still limited because the silicon expands and contracts dramatically when charged and discharged, causing cracking and pulverization that limit the battery lifetime.
Approximately 1,700 scientists visit SSRL annually to conduct experiments in broad disciplines including life sciences, materials, environmental science, and accelerator physics. Science highlights featured here and in our monthly newsletter, Headlines, increase the visibility of user science as well as the important contribution of SSRL in facilitating basic and applied scientific research. Many of these scientific highlights have been included in reports to funding agencies and have been picked up by other media. Users are strongly encouraged to contact us when exciting results are about to be published. We can work with users and the SLAC Office of Communication to develop the story and to communicate user research findings to a much broader audience. Visit SSRL Publications for a list of the hundreds of SSRL-related scientific papers published annually. Contact us to add your most recent publications to this collection.
January 2017
X-ray reflectivity
BL2-1
December 2016
Over the past three years a team of researchers has worked to understand the thermodynamic transitions in the antiferromagnetic ferroelectric BiFeO3 with La substitutions in relation to a new strategy for finding the ultimate magnetoelectric single phase material. The researchers made the striking finding that structural, ferroelectric, and magnetic phases evolve due to strong spin-lattice coupling, thereby producing a multiferroic triple phase point where three competing multiferroic phases merge.
Scanning transmission x-ray microscopy
BL13-1
October 2016
Rare earth magnetic materials have many applications, such as MRI scanners, Maglev trains, and electric vehicles. Scientists are researching improvements to these magnets through optimizing the component materials. Taking a different approach, a team of scientists have studied the effects of nano-scale heterogeneity in the chemistry and structure of Nd2Fe14B, a very strong and widely-used rare earth magnet.
X-ray microscopy
BL6-2
October 2016
Researchers are evaluating the use of organic semi-conductive polymers instead of inorganic semiconductors for use in solar cells. Polymer semiconductors are more flexible and more easily applied, which could allow for more uses and lower production costs. Unfortunately, solar cell devices made of these organic materials tend to have less power conversion efficiency, largely due to the way the donor and acceptor molecules are arranged in the bulk heterojunction (BHJ) structures.
BL7-2
October 2016
RNA molecules, often bound to protein in complexes, play essential roles in many basic cellular processes in all life. Like with proteins, often these roles depend on the distinct 3-dimensional shapes the RNA molecules adopt. While much research has been done using traditional biophysical techniques to determine the predominant structure of many RNA folds, less is known about the array of shapes a certain type of RNA can adopt and how this ensemble of form affects function.
Biological Small-angle X-ray Scattering (BioSAXS)
BL4-2
September 2016
In materials science, the creation of composites by mixing of materials with different properties can lead to a new set of properties. To create a new type of nanocomposite material for semiconductors, a team of scientists chose to combine CdO and SnTe, materials with disparate optoelectric properties, one acting as an n-type (electron-rich) and the other a p-type (hole-rich) semiconductor.
BL11-3
September 2016
The continuing development of better lithium-ion batteries, which are common in consumer electronics, depends on improvements in the batteries’ chemical materials. Over the charge/discharge cycle of the battery, the electrochemistry and morphology of the material change, which can cause steric stresses and defects, leading to decreased battery performance. Modifications of the lithium compounds used at the cathode can help the batteries hold more charge and keep charge better over many charge/discharge cycles.
BL6-2c
August 2016
The nucleus, which contains the DNA in eukaryotic cells, has pores in the surrounding double membrane that actively transport biologically important molecules in and out. Controlling these processes is done by a macromolecular protein machine called the nuclear pore complex (NPC). The human NPC is very large, composed of around 1000 proteins of 34 different types, which assemble into a structure with eight-fold symmetry. Because of the important role the NPC plays in our cells and its role in various diseases, such as viral infections, cancers, and neurodegenerative diseases, researchers would benefit from a high-resolution structure of the NPC that reveals the ordering of all of its ~10 million atoms. A team of scientists has accomplished exactly this.
Macromolecular Crystallography
BL12-2
August 2016
Giant magnetic resistance (GMR) is a quantum mechanical phenomenon observed in thin structures made of alternating metal layers having differing ferromagnetic properties. When the adjacent ferromagnetic layers of these multilayer materials are magnetized in parallel, there is little electrical resistance, but when magnetization is antiparallel, there is higher resistance. This property allows these materials to be used as magnetic sensors, and thin-film magnetic multilayers have been a popular topic of research. A team of researchers has tested the atomic properties of a variety of nickel and gadolinium (Ni/Gd/Ni) thin-film multilayers.
BL13-1
July 2016
Many bacteria, including many colonizing our own gut biomes, produce hair-like pili structures on their surfaces. There are various types of pili used for different purposes, like exchanging genetic information (conjugation), movement, and adhesion. A bacterium builds pilus through oligomerization of protein subunits. A group of scientists have determined the structure of a new type of pilus, which they named the type V pilus.
Macromolecular Crystallography
BL9-2, BL11-1, BL12-2
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