Reliable, high-capacity energy storage systems are in demand as necessary components of electric vehicles, medical devices, grid storage systems, and a wide array of other applications. However, these technologies are either limited or unrealized due to the flammability and low energy density of current secondary (rechargeable) energy storage materials. With upwards of 10 times the energy density of current state-of-the-art energy storage systems and no flammable components, solid-state lithium-ion batteries (SSBs) are poised to address these issues and revolutionize the technology landscape. Before these systems can be implemented, however, a different set of issues must be overcome. Indeed, the most promising materials lack interfacial stability at high rates of charging due to the formation of voids, dendrites, volumetric growth of electrode particles, or formation of unfavorable solid electrolyte interphase (SEI) materials. Due to these issues, SSBs have yet to realize their full potential, as capacities are significantly reduced after only a few charge/discharge cycles. In order to solve these problems, it is necessary to understand exactly what mechanisms lead to instability and what kinds of physical couplings can be exploited to improve cyclability.
Overwhelming consensus in the literature is that current theoretical frameworks inadequately model the multifaceted, multiphysics behavior of energy storage materials. While some robust theoretical models exist, they either fail to account for non-negligible couplings, lack the dimensionality required to study interfacial stability, or are limited by their linearity. Further, magnetic couplings are nearly universally neglected in the battery modelling literature despite groundbreaking experimental evidence demonstrating the stabilizing effect of a properly oriented magnetic field. Almost all technological advancement is thus made through experimental trial and error, which is slow, laborious, and expensive. Progress is further hindered given that many experiments are designed based on flawed theories; for example, many researchers assume mechanical stability will be achieved if the Monroe-Newman criteria is met, but the uncoupled linear elastic assumptions required for this to hold are oftentimes unattainable.
My research has three key objectives: (1) the development of a fully coupled thermal-electrochemical-magnetic-mechanical (TECMM) free energy framework capable of describing nonlinear, arbitrarily coupled physical phenomena and associated dissipative mechanisms such as (visco)plasticity; (2) a theory capable of efficiently modelling interfacial evolution mechanisms such as growth, decay, and fracture; and (3) the implementation of a methodology to computationally solve problems posed by the theory via the Finite Element Method (FEM).
Timothy J. Carlson is a Ph.D. student studying computational mechanics at the University of California, Berkeley under Professor Sanjay Govindjee. He also consults for Dassault Systemes (ABAQUS) to improve their coupled electrochemistry simulation capabilities. His primary research area is battery multiphysics modeling and simulation, with tangential interests in applications of category theory to continuum mechanics and computational homogenization. He received his B.S. from Johns Hopkins University in 2022, where he majored in Civil Engineering and Mathematics. In 2024, he completed his M.S. in Structural Mechanics.
If you are interested in learning more about Tim's work, you can find his webpage here