Chemical engineering doctoral student spent summer researching restoration of degraded lithium ion batteries
For Marcos Lucero, fourth-year chemical engineering doctoral student and former participant in the U.S. Department of Energy’s (DOE) Office of Energy Efficiency and Renewable Energy (EERE) Energy Storage Internship Program, introduction to science, technology, engineering and math (STEM) came early as a child, when his oldest brother introduced him to science documentaries. As he grew up, he knew he wanted to study science and math.
After completing two summer internships during his undergraduate studies, Lucero was convinced that a career in STEM was where he belonged, and he went on to pursue a doctorate in chemical engineering at Oregon State University. When his thesis advisor informed him of the EERE Energy Storage Internship Program, Lucero became interested due to the possibility of studying novel battery chemistries and design.
“We both agreed that this would be an amazing opportunity where not only would I learn from the leaders in the battery field, but also I could apply the skills I learned in electrochemistry and X-ray spectroscopy to help to solve unique problems,” Lucero said.
The DOE EERE Energy Storage Internship Program offers hands-on, practical research and development projects focused on energy storage at U.S. national laboratories.
Under the mentorship of Marissa Wood, Ph.D., staff scientist at Lawrence Livermore National Lab (LLNL), Lucero spent 10 weeks during the summer of 2020 contributing research to the restoration of degraded lithium ion batteries.
“The research project was split into two major parts,” he said. “First, we degraded the pristine battery by chemically removing lithium from the host electrode material, a mixed metal oxide of lithium, nickel, manganese and cobalt, called NMC 811. Second, we attempted to restore the performance of the degraded material back to its pristine performance or better.”
The two major chemicals used to remove the lithium from NMC 811 were sulfuric acid and sodium perchlorate.
“We successfully removed lithium without removing the other metals, such as nickel, cobalt or manganese, from the material of the degraded battery we were attempting to restore the performance of,” Lucero explained. “In order to restore the performance of the material, we performed a low temperature heating of the lithium deficient battery material. This heating procedure was intended to stabilize the degraded material and was supported by theoretical work done at LLNL.”
Due to their long cycle life and high energy density, lithium ion batteries are being used in a wide range of applications, from earphones and laptops to car batteries and alarm systems.
“As the batteries begin to fail, there will be a need to repurpose these cells for other uses,” Lucero said. “If the degraded electrode on a failing battery can be restored back to its original performance without resynthesizing the battery material, this would dramatically reduce cost and be more environmentally sustainable. Therefore, the purpose of this project was to stabilize the degraded battery material through an inexpensive low temperature annealing, or slow cooling, process and create more sustainable recycling.”
The precursor materials that make up the mixed metal oxide of the NMC 811 cathode are composed of rare, high-cost metals such as lithium, nickel and cobalt, and recycling the batteries will reduce costs significantly.
“Additionally, these metals can be hazardous and can pollute soil and water supplies if they are not recycled,” he said. “Therefore, this work can potentially reduce the cost of batteries for consumers while preventing pollution.”
Lucero’s research experience within the EERE Energy Storage Internship Program allowed him to gain a better understanding of the fabrication process and the many parameters that can affect battery performance.
“After this experience, I began to implement a more systematic and rigorous fabrication procedure and testing protocol in my battery research,” he said. “The skills and knowledge I gained will help me in the future by allowing me to conduct battery research that is directly applicable to real conditions found in high-energy-density batteries.”
He recommended the EERE Energy Storage Internship Program to other students who are working on batteries or related research, saying, “The folks at LLNL made every effort to make my internship experience worthwhile. Additionally, my mentor provided me with great advice and perspective on the state-of-the-art research in the lithium ion battery field while providing me with insights on methods to start my own independent research project.”
While he still has a few years before he graduates with his doctoral degree, Lucero’s career goals are to become a research scientist at a national laboratory or in academia.
“Based on my intern experience with EERE, I am certain this is the route I will take,” he said. “I plan to apply to the program next year as the research is ongoing and future experiments will be carried out by Dr. Marissa Wood.”
The EERE Energy Storage Program is funded by the DOE and administered through the Oak Ridge Institute for Science and Education (ORISE). ORISE is managed for DOE by Oak Ridge Associated Universities (ORAU).