2020 Virtual AIChE Annual Meeting

(3gd) Designing Polymeric Interphases for Reactive Metal Anodes

Authors

Sanjuna Stalin - Presenter, Cornell University
Lynden A. Archer, Cornell University
Safe, cost effective and long-lasting electrical energy storage devices are essential to sustain progress in electrified transportation, consumer electronics and autonomous machines. Lithium Ion Batteries (LIBs) have emerged as the dominant technology in this commercial space. My thesis project focuses on enabling an energy storage technology that has substantially higher specific energy and range using so called Lithium Metal Batteries (LMBs). Here the graphitic anode used in LIBs is replaced with a Lithium metal block. LMBs are considered attractive because of their high theoretical energy density but are not available today primarily because the lithium metal
anode poses multiple challenges. Among them, the most difficult are the metal’s propensity to form rough electrodeposits at current densities below the diffusion limit and to react with species in its surroundings to initiate thermal runaway.

Design of electrolytes and solid electrolyte interphases (SEI) that can influence transport of ions within the bulk and at the electrode/electrolyte interface has garnered significant attention for addressing this issue. In this presentation, I will discuss using theoretical predictions from linear stability analysis as a guide to design polymers that are utilized as model solid electrolyte interphases, to understand how different parameters influence the nucleation and growth rate of lithium electrodeposits. By systematically modifying parameters such as crosslinker and side chain chemistry as well as the polymeric network architecture, we study how properties such as impedance, shear modulus, surface energy and cation diffusivity within these polymeric interphases correlated to the morphology and growth rate of the deposited lithium. We then propose initial guidelines for creating polymeric interphases that can stabilize electrodeposition of reactive metals.

Research Interests:

I aim to use my expertise in fundamental chemical engineering principles and polymeric science to enable the advancement of next generation electrochemical energy
technologies. Transport limitations at different length scales are often the culprit that set back the realization of these systems. Using advanced nanoscale and operando characterization tools to fundamentally understand these limitations and designing novel and functional materials from polymeric constituents to address them will be the key theme of my career in academia in the future.