Causes of binder damage in porous battery electrodes and strategies to prevent it

The mechanisms for binder delamination from electrode particles in porous lithium-ion electrodes are considered. The problem is analysed using a model that makes use of a multiscale continuum description of the battery electrode and specifically accounts for the viscoelastic properties of the binder [9]. This model predicts the evolution of the stress fields in the binder in response to: (i) binder swelling due to electrolyte absorption during cell assembly, and; (ii) shrinkage and growth of the electrode particles during cell cycling. The model predictions provide a cogent explanation for morphological damage seen in microscopy images of real cathodes. The effects of altering electrode particle shape, binder rheology and cycling rates on binder delamination are all investigated and used to make suggestions on how electrode lifetimes could be extended.