Fingerprinting Redox Heterogeneity in Electrodes during Extreme Fast Charging

Abstract

Conventionally, battery electrodes are rationalized as homogeneous reactors. It proves to be an erroneous interpretation for fast transients, where mass transport limitations amplify underlying heterogeneities. Given the lack of observability of associated fast spatiotemporal dynamics, redox activity in inhomogeneous electrodes is superficially explored. We resort to a physics-based description to examine the extreme fast charging of lithium-ion battery electrodes. Representative inhomogeneity information is extracted from electrode tomograms. We discover such electrodes to undergo preferential intercalation, localized lithium plating and nonuniform heat generation as a result of distributed long- and short-range interactions. The spatial correlations of these events with the underlying inhomogeneity are found to be nonidentical. Investigation of multiple inhomogeneity fields reveals an exponential scaling of plating severity and early onset in contrast to the homogeneous limit. Anode and cathode inhomogeneities couple nonlinearly to grow peculiar electrodeposition patterns. These mechanistic insights annotate the complex functioning of spatially nonuniform electrodes.

Effect of Anode Porosity and Temperature on the Performance and Lithium Plating During Fast‐Charging of Lithium‐Ion Cells

“…[ 31 ] Mesoscale electrochemical modeling predicted electrode microstructure inhomogeneity, and this gave rise to localized plating that occurred both earlier (at ≈24 s) and more severely (≈twice) compared with homogeneous electrodes during fast charging. [ 32 ]…”

“…[31] Mesoscale electrochemical modeling predicted electrode microstructure inhomogeneity, and this gave rise to localized plating that occurred both earlier (at %24 s) and more severely (%twice) compared with homogeneous electrodes during fast charging. [32] Figure 10a shows how the characteristic ionic diffusion time is shorter for the high-porosity electrodes, even though the calendered electrodes are thinner, with difference increasing with decreasing ionic transport coefficient. Figure 10b generalizes the approach to different porosities, considering doublets (thickness, theoretical porosity) that preserve the active material theoretical capacity (e.g., Figure 10c).…”

Myth and Reality of a Universal Lithium‐Ion Battery Electrode Design Optimum: A Perspective and Case Study

“…For instance, they can be used to evaluate existing structuring concepts or identify thermal hotspots and local lithium plating. [64][65][66] Kespe et al used 3D microstructure simulations to improve the electric conductivity of an electrode by optimizing the spatial location of the carbon-binder domain (CBD). [67] Chouchane et al looked at the CBD from a production perspective.…”

A Simplified Mathematical Model for Heating-Induced Thermal Runaway of Lithium-Ion Batteries

“…37 However, the developed approach requires a relatively larger number of input parameters for the heat source. 29,30,38 and fast charging [39][40][41][42] , the present study is focused on TR induced by overheating.…”