Electron microscopy (EM), specifically in situ, is a powerful analytical and characterisation technique that is widely used to study electrode materials for battery applications. Significant strides have been made to process samples, obtain high resolution images, perform in situ experiments and provide particle-level insights into battery function. In situ EM techniques are immediately applicable to the study of electrode materials for battery applications to provide insight into dynamic function of these materials at the particle and atomic resolution. The purpose of this review is to capture the in situ (and ex situ) EM methods currently being used and their application to battery materials and is designed to persuade future research efforts into the design of better battery materials with electron microscopy playing an integral role in mechanistic understanding of function.