Researchers at UCLA have developed a pioneering imaging technique, electrified cryogenic electron microscopy (eCryoEM), which for the first time provides real-time, high-resolution views of the internal processes of lithium-metal batteries during charging cycles. By enabling scientists to see details at a scale smaller than the wavelength of light, the method sheds new light on how the corrosion layer—crucial to battery longevity and performance—forms and evolves within next-generation energy storage devices.
Historically, battery research has been constrained to before-and-after snapshots, leaving a gap in understanding the intricate reactions occurring as batteries operate. The new eCryoEM process involves rapidly freezing the batteries with liquid nitrogen to lock dynamic reactions in place, yielding sequential images that act like a frame-by-frame animation of the corrosion film’s evolution. Insights gathered from these observations indicate that the corrosion layer´s growth is initially limited by lithium’s reaction rate rather than electron diffusion through the film, overturning previous assumptions. Notably, electrolytes engineered for superior performance can triple the rate of layer formation during this critical early stage, highlighting the importance of enhancing electrolyte reactivity—rather than focusing solely on the corrosion layer’s diffusion properties—for advancing battery technology.
The implications of this discovery reach beyond battery design alone. Detailed visualizations of chemical reactions provided by eCryoEM could inform improvements in energy storage for consumer electronics and electric vehicles. The ability to potentially double the energy density of current lithium-ion batteries would have far-reaching consequences for technology independence and sustainability. Moreover, the principles and techniques behind eCryoEM could also benefit fields such as biology, where direct observation of rapid cellular processes is key to breakthroughs in diagnostics and medicine. While technical and industrial scaling challenges remain, this advancement marks a crucial step toward next-generation batteries with enhanced life, efficiency, and safety, driven by a deeper understanding of their fundamental chemistry.
