Understanding Battery Performance via Atomistic-based Theory and Simulations
Dr. Perla Balbuena, Texas A&M University
Abstract: Li-metal anode electrodeposition and side reactions take place simultaneously during cycling. Since the side reactions leading to the solid-electrolyte interphase (SEI) depend on the electrolyte composition (among other factors), a rich SEI morphology evolves while also interacting with the plating and stripping reactions. To address this complex scenario, we have used kinetic Monte Carlo techniques. By computing the Coulombic efficiency and observing the evolution of the Li metal anode surface over more than 150 cycles, we demonstrate how the details of the interfacial phenomena affect the battery performance.
Organic Batteries for a More Sustainable Future
Dr. Jodie Lutkenhaus, Texas A&M University
Abstract: Cobalt, nickel, and lithium are essential ingredients in today’s lithium-ion batteries (LIBs), but their continued use presents economic, ethical, and environmental challenges. Society must now begin to consider the implications of a LIB’s full life cycle, including the carbon footprint, the economic and environmental costs, and material access. These challenges motivate the case for degradable or recyclable batteries sourced from earth-abundant materials whose life cycle bears minimal impact on the environment. This presentation considers organic polymer-based batteries, which have the potential to address many of these issues. Redox-active polymers form the positive and negative electrodes, storing charge through a reversible redox mechanism. We demonstrate polypeptide radical batteries that degrade on command into amino acids and by-products as a first step toward circular organic batteries. Further, we show the recycling of redox-active polymer electrodes using a solvent-based approach. Polymer-air batteries are examined as high-capacity alternatives to metal-air batteries. The molecular mechanism for each case is investigated, revealing pathways forward for improving each polymer’s performance. Taken together, organic batteries offer the promise of a circular platform free of critical elements.
Characterizing thermal runaway and mitigating the propagation of thermal runaway in lithium-ion battery modules
Dr. Judy Jeevarajan, Electrochemical Safety Research Institute (ESRI), Part of UL Research Institutes
Abstract: Thermal runaway of lithium-ion cells and batteries can occur due to many different off-nominal conditions. The off-nominal conditions can be broadly categorized into thermal, mechanical and electrical. Irrespective of the cause, worst case events with li-ion cells and batteries result in thermal runaway that is manifested as very high temperatures with the occurrence of fire and/or smoke. The presentation will focus on results of characterizing the fire, smoke and particulate emissions. In addition to this, a quick overview will be presented of the research studies carried out at ESRI on using various materials and designs to mitigate the propagation of thermal runaway.
How the environment around electrocatalytic active sites influences reactivity
Dr. Joaquin Resasco, University of Texas at Austin
Abstract: Electrochemical processes offer an appealing way to store intermittent energy produced by renewable electricity sources and sustainably produce chemicals that are currently derived from petroleum. It is well known that the performance of these processes is affected not only by the composition and structure of the (electro)catalyst used, but also by the electrolyte in which the reaction is run. In particular, the choice of electrolyte cation markedly impacts the performance of catalysts for many critical reactions. But the reason behind these changes remains disputed. In this talk, I will describe a physical model we have developed that helps rationalize these effects. We propose that the electric field present at the catalyst surface is sensitive to the identity of the cation in the electrolyte. This interfacial field alters the energetics of the reaction and consequently catalytic performance. These ideas help deepen our understanding of catalysis in electrochemical environments and provide new tools for the design of high efficiency fuel cells, electrolyzers, and electro-synthetic cells.