Renewable energy capacity is increasing and expected to meet global energy demand this century. Existing technology will thus ensure the generation of clean, renewable energy. But the storage and rapid delivery of this abundant supply remains a critical unmet challenge. Development of new materials that store large quantities of charge and rapidly deliver it on demand is vital to any global transition to a low- or zero-carbon energy economy. This CAREER award project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, focuses on the study of fundamental materials chemistry to advance design principles for safe, fast-charging, and long-lasting Li-ion battery materials. The research focuses on linking chemical and structural properties of materials with their ability to conduct Li-ions. Fast Li-ion transport is necessary for high power applications that benefit society such as electric vehicles, power tools, and portable electronic devices. PI Sambur’s team gains new insight into Li-ion transport by developing new imaging tools that reveal Li-ion motion at the nanoscale. These microscopic measurements enable the researchers to make strong connections between materials chemistry and critical energy storage performance metrics. Through this project, the PI promotes microscopy education and increase accessibility to microscopy tools among elementary, high school, undergraduate, and graduate-level students. Imaging is an essential skill in all scientific disciplines, but there are few opportunities for students to receive an education in microscopy. One issue is that university chemistry departments and K-12 schools lack microscopy tools to educate large numbers of students. The PI plans to develop low-cost microscopes with experiential learning activities tailored to different age groups to address this critical need. This effort aims to promote science to middle and high school students, particularly underrepresented women and Hispanic/Latinx students in the Colorado STEM education pipeline.
The major scientific roadblock to a global renewable energy economy is inadequate energy storage materials. Exhaustive research into new battery materials has made clear that future innovation will stem from fundamental materials design principles that are free from the element of art inherent in the fabrication of electrodes. Rather than relying on mix and measure empiricism, single particle measurements can establish materials design principles by linking known solid state chemistry principles to fundamental ion/electron transport processes that determine charge storage capacity and rate. However, such single particle studies are often slow and tedious. This proposal advances high-throughput single particle-level light microscopy and spectroscopy, in conjunction with electron, X-ray, and atom probe tomography techniques, to forge new links between crystal structure modifications, electronic structure, and electrochemical properties. The research focuses on Wadsley-Roth crystallographic shear structures that exhibit extraordinarily fast Li-ion diffusion coefficients in bulk-like (micron) material, signaling that the built-in structural motifs in these complex oxides are the key to unlocking critical design principles for tuning ionic diffusivity. The PI’s team aims to define how Li-ion diffusivity scales with the chemistry, stoichiometry, and block size of Wadsley-Roth compounds. The microscopy tools are used to reveal how the type, concentration, and arrangement of surface facets and Wadsley defects influences electrochemical properties. The methodologies innovated herein will be generally applicable to a wide range of existing materials and those that have yet to be discovered. An expected significant outcome from the structure/property relationships uncovered in this research will be design principles for a safe, high-rate anode material for use in Li-ion batteries. The PI is determined to ensure that the intellectual foundation of this research project has a broad impact on society through the development of low-cost microscopes and activities designed to educate 6th-12th grade students in mapping the functional properties of real-world systems such as solar cells. The activities guide students into a grade-appropriate, working knowledge about how the energy conversion efficiency of hobby-grade solar cells correlates with materials heterogeneity. The PI works closely with STEM experts in Colorado State University’s Natural Science Education Outreach Center to disseminate the kits to middle and high school science labs across Colorado, complementing existing University outreach programs.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
