Crack propagation has been extensively spotlighted as a main reason for the degradation of secondary‐particle‐type active materials, including LiNixMnyCo1−x−yO2 (NMC). Numerous experimental analyses and 3D‐modeling‐based investigations have been conducted to unravel this complicated phenomenon, especially for nickel‐rich NMCs, which experience substantial crack propagation during high‐voltage, high‐temperature, or high‐depth‐of‐discharge operations. To fundamentally clarify this unavoidable degradation factor and permit its suppression, a digital‐twin‐guided electro–chemo–mechanical (ECM) model of a single few‐micrometer‐sized LiNi0.7Mn0.15Co0.15O2 (NMC711) particle is developed in this study using a 3D reconstruction technique. Because the digital twin technique replicates a real pore‐containing NMC711 secondary particle, this digital‐twin electrochemical model simulates voltage profiles even at 8C‐rate within an error of 0.48% by fitting two key parameters: diffusion coefficient and exchange current density. The digital‐twin‐based ECM model is developed based on the verified electrochemical parameters and mechanical properties such as lithium‐induced strain from axis lattice parameters and stress–strain curve measured by nanoindentation. Using this model, the electrochemical‐reaction‐induced mechanical properties including strain, stress, and strain energy density are also visualized in operando in a single NMC711 particle. Finally, the advanced operando ECM analysis allows for the diagnosis of crack formation, highlighting the effectiveness of this platform in elucidating crack formation in active materials.

Crack Formation Diagnosis In article number 2204328 by Sung‐Soo Kim, Yong Min Lee, and co‐workers, a single few‐micrometer‐sized LiNi0.7Mn0.15Co0.15O2 particle is digital‐twinned using FIB/SEM. The particle's electrochemical and mechanical properties are obtained through single particle measurement, nanoindentation, and axis lattice parameters. The digital‐twin‐driven electrochemo‐mechanical model is developed using the digitaltwin structure and parameters. This model performs digital‐twin operando analysis of electrochemical and mechanical properties. Finally, this advanced analysis allows the diagnosis of crack propagation.

The increasing demand for short charging time on electric vehicles has motivated realization of fast chargeable lithium‐ion batteries (LIBs). However, shortening the charging time of LIBs is limited by Li+ intercalation process consisting of liquid‐phase diffusion, de‐solvation, SEI crossing, and solid‐phase diffusion. Herein, we propose a new strategy to accelerate the de‐solvation step through a control of interaction between polymeric binder and solvent‐Li+ complexes. For this purpose, three alkali metal ions (Li+, Na+, and K+) substituted carboxymethyl cellulose (Li‐, Na‐, and K‐CMC) are prepared to examine the effects of metal ions on their performances. The lowest activation energy of de‐solvation and the highest chemical diffusion coefficient were observed for Li‐CMC. Specifically, Li‐CMC cell with a capacity of 3 mAh cm−2 could be charged to >95% in 10 min, while a value above >85% was observed after 150 cycles. Thus, the presented approach holds great promise for the realization of fast charging.