Stochastic Analysis of Diffusion Induced Damage in Lithium-Ion Battery Electrodes

Fracture due to diffusion induced stress of electrode active particles has been identified as one of the critical factors for capacity fade and impedance rise in lithium-ion batteries. The inherent stochastics underlying the crack formation and propagation in brittle intercalation materials is critical toward fundamental understanding of the degradation phenomena limiting battery life and performance. A stochastic methodology has been developed to characterize the diffusion-induced damage inside lithium-ion battery electrode active particles. Presence of a "critical" initial crack length at which maximum stress occurs has been identified. A damage parameter has been introduced to characterize the impact of fracture on solid state lithium diffusion. The importance of active particle size, concentration dependent elastic moduli and cycling on the fracture stochastics and concomitant electrochemical performance decay has been elucidated along with the concept of a fracture phase-map. (C) 2013 The Electrochemical Society. All rights reserved.