Over the last two decades, we have witnessed a paradigm change in the way we characterize materials using electron microscopy. This latest revolution in resolution began in the late 1990’s with the first successful implementation of an objective lens aberration corrector, which improved the spatial resolution of transmission (TEM) and scanning transmission electron microscopy (STEM) by more than a factor of two to below 50 pm. These developments were followed by faster, more sensitive direct electron (CMOS) detectors, monochromated electron sources for electron spectroscopy and, most recently, magnetic field-free lenses. As the result of these transformational discoveries, we are now able to study materials with unprecedented resolution, sensitivity and precision. While spatial and energy resolutions better than 60 pm and 10 meV have been reported, aberration-corrected TEM has also enabled a large variety of in-situ experiments at close to atomic resolution.

In my talk, I will highlight several examples where atomic-resolution in-situ, multi-modal characterization and first-principles modeling are used to unravel the fundamental structure-property relationships of materials with potential applications in high-efficiency photovoltaic devices, rechargeable batteries or electro-catalysis. I will further introduce a novel approach to characterizing phase transitions in fluids at high spatial and isotopic resolution. I will conclude by presenting my vision for the future of electron microscopy, including new instrument designs as well as operando multi-modal methods combining electron scattering with transport measurements.