Microstructures and Energy Storage Materials
Lawrence Livermore researchers have developed a framework to improve materials design for advanced, solid-state batteries. Combining data-driven machine-learning techniques with a mesoscale material modeling framework informed by atomistic simulations, the Laboratory team analyzed how microstructural features such as grain boundaries, interfaces, and phase connectivity impact material properties. The approach, published September 17, 2024, in Energy Storage Materials, enables deeper understanding of material influences on ionic transport, which influences battery performance.
The team focused on two-phase composite cathode materials for solid-state batteries. “We digitally generated hundreds of distinct microstructures and ultimately found that microstructural feature diversity can significantly impact effective transport properties,” says Livermore’s Longsheng Feng, the paper’s lead author. The study highlighted the importance of engineering intrinsic interface properties as well as their microstructural arrangements to optimize battery performance. By providing insights into the interplay between interface, microstructure, and ionic transport, the research offers a pathway to designing more efficient and reliable solid-state batteries. Co-author Tae Wook Heo says, “Our modeling framework can be extended to investigate other critical microstructural and chemical features, representing the broader impacts and practicality of this approach for materials in energy storage applications and beyond.”
Contact: Longsheng Feng (925) 423-8332 (feng8 [at] llnl.gov (feng8[at]llnl[dot]gov)) or Tae Wook Heo (925) 424-3216 (heo1 [at] llnl.gov (heo1[at]llnl[dot]gov)).
Mapping Bacterial Communities
Toxin−antitoxin (TA) systems—pairs of self-destructive “toxins” (often a protein) and protective “antitoxins” (either a protein or an RNA strand)—are widespread within bacterial communities and central to the communities’ interactions and evolution. In a study published October 15, 2024, in Molecular Biology and Evolution, Lawrence Livermore researchers investigated TA systems as a better targeted alternative to broad-spectrum antibiotics that can disrupt healthy microbiomes and lead to opportunistic infections in patients.
TA genes are frequently inherited through horizontal gene transfer (HGT), whereby bacteria acquire and exchange genetic information found in the surrounding environment. Such community-based evolution enables rapid bacterial adaptation that fuels antibiotic resistance. The Livermore team used a machine-learning technique to analyze a 10,000-plasmid HGT network based on the unique TA signatures present. The researchers found that TA systems create distinct signatures within bacterial communities, reflecting plasmid competition and interactions with hosts and viruses. These signatures aid precise identification of foreign bacteria in mixed populations, thus providing a targeted approach to managing infections. Livermore postdoctoral scientist Jonathan Bethke says, “Looking at bacteria through a community lens could enable precision treatments to target pathogens, such as salmonella, while preserving the health of an individual’s microbiome.”
Contact: Jonathan Bethke (925) 423-7437 (bethke2 [at] llnl.gov (bethke2[at]llnl[dot]gov)).
Engineered Properties with Cellular Fluidics
Livermore researchers have identified a multimaterial additive-manufacturing technique based on the cellular fluidics concept they introduced in 2021. Cellular fluidics harnesses the natural phenomenon of capillary action, which permits fluid uptake against gravity in small, confined spaces. The researchers’ work, published October 21, 2024, in Advanced Materials Technologies, presents a technique enabling precise fabrication of composite materials with engineered mechanical properties. Specifically, 3D-printed lattice scaffolds with custom-designed unit cells guide liquid (infill) materials, such as polymers and epoxies, into desired patterns. The materials are then cured in place to produce linked, multimaterial structures. By tuning parameters of the scaffold unit cells such as size, strut diameter, and surface wetting, the researchers achieved heightened control over fluid flow and retention, creating composites with tailored mechanical responses. Mechanical performance can be improved with adjustments to lattice architecture and infill material.
This technique expands the range of manufacturable materials and geometries, enabling applications in aerospace, biomedical engineering, and advanced sensing platforms. Materials engineer and lead author Hawi Gemeda says, “In future work, we want to widen the design space by expanding the technique to other composite systems such as ceramics, metals, and biomaterials, and explore ways to use the unit cells for patterning multiple materials in the same scaffold.”
Contact: Hawi Gemeda (925) 495-9976 (gemeda1 [at] llnl.gov (gemeda1[at]llnl[dot]gov)).
