2025 AIChE Annual Meeting

(150a) New Frontiers for Cryo-EM in Nanoscale Science for Energy and Health

Author

Cryogenic electron microscopy (cryo-EM) won the 2017 Nobel Prize in Chemistry for its profound impact on the field of structural biology, most notably elucidating the spike protein structure of COVID-19 to accelerate vaccine development. In 2017, this powerful technique was introduced to energy science, leading to new insights into battery operation and failure. Although cryo-EM has made significant contributions to our understanding of battery materials at equilibrium, it has not advanced beyond the decades-old approaches used in biology, making cryo-EM and conventional techniques blind to the dynamics of nanoscale liquid-solid interfaces away from equilibrium. We have invented electrified cryo-EM (eCryo-EM), a breakthrough innovation that rapidly freezes and kinetically traps electrochemical reactions while they occur to enable direct nanoscale imaging of dynamic interfaces. Surprisingly, we discover an ultrathin (<2 nm) inorganic layer that partitions the corrosion film formed on battery electrodes, which revises our previous understanding of ion and electron transport through this interfacial structure. Slower growth kinetics of this ultrathin layer measured by eCryo-EM correlates with improved battery performance. Our findings reconcile many longstanding contradictions from past models of this poorly understood corrosion film and provide new insight for engineering its passivation properties that are critical for next-generation batteries. More broadly beyond the implications for battery research, eCryo-EM introduces a new paradigm for exploring the electrified interfaces that underpin fundamental processes spanning chemistry and biology.