Dynamics of particle network in composite battery cathodes

Abstract

Improving composite battery electrodes requires a delicate control of active materials and electrode formulation. The electrochemically active particles fulfill their role as energy exchange reservoirs through interacting with the surrounding conductive network. We formulate a network evolution model to interpret the regulation and equilibration between electrochemical activity and mechanical damage of these particles. Through statistical analysis of thousands of particles using x-ray phase contrast holotomography in a LiNi 0.8 Mn 0.1 Co 0.1 O 2 -based cathode, we found that the local network heterogeneity results in asynchronous activities in the early cycles, and subsequently the particle assemblies move toward a synchronous behavior. Our study pinpoints the chemomechanical behavior of individual particles and enables better designs of the conductive network to optimize the utility of all the particles during operation.

Data-Driven Lithium-Ion Battery Cathode Research with State-of-the-Art Synchrotron X-ray Techniques

“…For the output data, it is necessary to ensure the precision rate and recall rate, and more importantly, it is interpretable and can be understood by scientists in the battery field. We assess the interpretability of ML approaches by using models that are intrinsically interpretable 27,29 feeding physically meaningful features into the algorithms 39 and validating by external techniques. 27,39 For example, the finding of ML models can be validated by theoretical calculations or other experimental techniques.…”

“…With the identified thousands of NCM particles, we also tracked their behavior with time and thus determine the relationship between structure and battery performance as well as the deterioration of the cathode. 39 These works provide new perspectives and experimental basis for electrode and particle-scale designs for battery cathode. They highlight the use of ML tools for pattern recognition for analyzing the high-resolution phase-contrast holo-tomographic data of real-world battery cathode electrodes under different conditions.…”

Chemomechanics of Rechargeable Batteries: Status, Theories, and Perspectives

“…This experimental observation is in good consistence with the finite elemental modeling results, highlighting the synergy between the cutting-edge experimental capabilities and the theoretical modeling. Moreover, the automatic identification of many particles in a real-world electrode not only can be utilized to study individual particles’ behavior with statistical significance but also facilitated the investigation of particle-to-particle interactions, revealing a dynamic particle network evolution that governs the cathode degradation …”

Deep‐Learning‐Enabled Crack Detection and Analysis in Commercial Lithium‐Ion Battery Cathodes

“…They are relatively flexible to set up and allow multiple characterization techniques to study the particle behavior in a statistically meaningful manner. [ 8–10 ]…”

“…They are relatively flexible to set up and allow multiple characterization techniques to study the particle behavior in a statistically meaningful manner. [8][9][10] In this work, we utilize micro-and nanoscale X-ray tomography to image the inner structure of an electrochemically abused 18650-type cylindrical cell. The cracking phenomenon in commercial cells is of particular interest to this industry because the manufacturing procedure is often already "optimized" through trial-and-errors.…”