Modeling of Porous Lithium Metal Electrodes: Turning the Li-Dendrite Problem Around. Issue 7 (1st July 2022)

• Record Type: Journal Article
• Authors: Bucci, Giovanna; Swamy, Tushar; Craig Carter, W.; Behandish, Morad
• Is Part Of: Journal of the Electrochemical Society. Volume 169:Issue 7(2022)
• Publication Date: 2022-07-01
• Subjects: solid state battery -- lithium metal anode -- porous electrode -- mesoscale modeling -- mixed electron/ion conductor; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/1945-7111/ac79d0
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : The properties of rechargeable lithium-ion batteries are determined by the electrochemical and kinetic properties of their constituent materials as well as by their underlying microstructure. Microstructural design can be leveraged to achieve a leap in performance and durability. Here we investigate a porous electrode structure, as a strategy to increase the surface area, and provide structural stability for Li-metal anodes. The porous architecture consists of a mixed electron/ion conductor that function as a scaffold for lithium metal deposition. A new finite element model was developed to simulate the large topological changes associated with Li plating/stripping. This model is used to predict the current density distribution as a function of material and structural properties. A dimensionless quantity that combines Li-ion conductivity, surface impedance and average pore size is shown to be a good indicator to predict the peak current density. Preventing current localization at the separator reduces the risk of cell shorting. The analyses show that the peak current scales as ( hG ) 1/2, where h is the ratio between surface and bulk conductivity and G is the average pore size. Stability analyses suggest that the growth is morphologically stable, and that confining Li-plating into pores can enable high-energy density solid-state batteries.