Transmission electron microscopy in energy chemistry: Current applications and future perspectives

The rapid advancement of energy-related technologies has led to increasingly complex material systems featuring hierarchical structures, heterogeneous interfaces, and dynamic behavior. Transmission electron microscopy (TEM), with its unparalleled spatial resolution, imaging versatility, and analytical capabilities, provides unique insights into these systems by enabling direct visualization of structure–property relationships at the atomic scale. This review highlights the essential role of modern TEM and scanning TEM (STEM) techniques in energy chemistry. We introduce key imaging modalities alongside complementary spectroscopic and diffraction-based characterization methods. Representative applications are presented across three major categories of energy materials: energy conversion materials, energy storage systems, and nanoporous materials for catalysis and separation. These examples illustrate how careful selection of imaging modes and dose control strategies enables meaningful structural analysis, even for highly beam-sensitive or metastable systems. We conclude with an outlook on future directions, addressing current limitations and emphasizing the need for low-dose, in situ/operando, three-dimensional, and diffraction-based approaches to probe structural complexity under realistic operating conditions.