Damage and Crack Analysis in a Li-Ion Battery Electrode Using Random Spring Model

Lithium-ion batteries (LiB) are widely used in the electronics industry (such as, cell phones and laptop computers) because of their very high energy density, which reduced the size and weight of the battery significantly. LiB also serves as a renewable energy source for the transportation industry (see Ref. [1,2]). Graphite and LiCoO₂ are most frequently used as anode and cathode material inside LiB (see Ref. [2,3]). During the charging and discharging process, intercalation and de-intercalation of Li occur inside the LiB electrodes. Non-uniform distributions of Li induce stress inside the electrodes, also known as diffusion induced stress (DIS). Very high charge or discharge rate can lead to generation of significant amount of tensile or compressive stress inside the electrodes, which can cause damage initiation and accumulation (see Ref. [4]). Propagation of these micro-cracks can cause fracture in the electrode material, which impacts the solid electrolyte interface (SEI) (see Ref. [2,3,5]). Concurrent to the reduction of cyclable Li, resistance between the electrode and electrolyte also increases, which affects the performance and durability of the electrode and has a detrimental consequence on the LiB life (see Ref. [6]).