Cryo−electron microscopy, powerful assistant for advancing battery

As one of the most efficient energy storage devices to date, lithium–ion batteries have been commercialized for over 30 years. Traditional lithium–ion batteries are gradually approaching the energy density bottleneck, so many new advanced battery systems have been widely studied. However, their performance still cannot meet the requirements of commercialization. The performance improvement of these emerging battery systems relies on a deep understanding of materials/structures, but these are sensitive to air and electron radiation, making the characterization and analysis extremely challenging. Since its first application in battery research in 2017, cryogenic electron microscopy has been used to characterize battery materials and interfaces, and exciting results benefiting from this are increasingly being reported. In this review, we mainly focus on the evolution and interaction of lithium dendrites and solid electrolyte interphase layers, and summarize the reports of cryogenic technology in other related fields of lithium–ion batteries. Finally, the application prospects of cryogenic electron microscopy technology are also discussed. [Display omitted] •Cryo-EM provide ideas for the development of new advanced batteries.•Cryo-EM technology runs through the entire life of battery research.•Cryo-EM technology is no longer just a supplementary but a necessary.