Analytical design of electrode particle debonding for battery applications

Abstract

A physics-based analytical methodology is presented to describe the debonding of a statistically representative electrochemically active particle from the surrounding binder-electrolyte matrix in a porous electrode. The proposed framework enables to determine the space of C-Rates and electrode particle radii that suppresses or enhances debonding. Results are graphically summarized into maps where four debonding descriptions are identified: (a) the spontaneous debonding description, which occurs when the electrode particle spontaneously detaches from the matrix; (b) the continuous debonding description, which occurs when the electrode particle gradually loses contact with the surrounding matrix; (c) the electrochemical cycling fatigue description, which causes gradual growth of the flaw due to electrochemical cycling; and (d) the microstructural debonding description, which is a result of the microstructural stochastics of the electrode and is embodied in terms of the debonding probability of particles. The particle-dependent critical C-Rates for debonding power-law relation enables the experimental identification of individual failure mechanisms, thereby providing a context to formulate design strategies to minimize debonding and provide robust, physics-based, phenomenological, and statistics-based estimates for electrochemically driven failure.