While Li ion batteries are intended to be operated within a mild temperature window, their structural and chemical complexity could lead to unanticipated local electrochemical events that could cause extreme temperature spikes, which, in turn, could trigger more undesired and sophisticated reactions in the system. Visualizing and understanding the response of battery electrode materials to thermal abuse conditions could potentially offer a knowledge basis for the prevention and mitigation of the safety hazards. Here we show a comprehensive investigation of thermally driven chemomechanical interplay in a Li_0.5Ni_0.6Mn_0.2Co_0.2O₂ (charged NMC622) cathode material. We report that, at the early stage of the thermal abuse, oxygen release and internal Li migration occur concurrently, and are accompanied by mechanical disintegration at the mesoscale. At the later stage, Li protrusions are observed on the secondary particle surface due to the limited lithium solubility in non-layered lattices. The extraction of both oxygen and lithium from the host material at elevated temperature could influence the chemistry and safety at the cell level via rearrangement of the electron and ion diffusion pathways, reduction of the coulombic efficiency, and/or causing an internal short circuit that could provoke a thermal runaway.

The shuttling behavior and slow conversion kinetics of the intermediate lithium polysulfides are the severe obstacles for the application of lithium‐sulfur (Li‐S) batteries over a wide temperature range. Here, an engineered lamellar yolk–shell structure of In₂O₃@void@carbon for the Li‐S battery cathode is developed for the first time to construct a powerful barrier that effectively inhibits the shuttling of polysulfides. On the basis of the unique nanochannel‐containing morphology, the continuous kinetic transformation of sulfur and polysulfides is confined in a stable framework, which is demonstrated by using X‐ray nanotomography. The constructed Li‐S battery exhibits a high cycling capability over 1000 cycles at 1.0 C with a capacity decay rate as low as 0.038% per cycle, good rate performance, and temperature tolerance at −10, 25, and 50 °C. A nondestructive in situ monitoring method of the interfacial reaction resistance in different cycling stages is proposed, which provides a new analysis perspective for the development of emerging electrochemical energy‐storage systems.

FeS nanoparticles were self-assembled by Shewanella oneidensis MR-1, and the biosynthesis yield and rate can be regulated by regulating the precursor content. The resulting Bio-FeS nanoparticles exhibit excellent in vivo therapeutic performance.

A full-field, transmission x-ray microscope (TXM) operating in the energy range of 7–11 keV has been installed at the U7A beamline at the National Synchrotron Radiation Laboratory, a second generation synchrotron source operating at 0.8 GeV. Although the photon flux at sample position in the operating energy range is significantly low due to its relatively large emittance, the TXM can get high quality x-ray images with a spatial resolution down to 50 nm with acceptable exposure time. This TXM operates in either absorption or Zernike phase contrast mode with similar resolution. This TXM is a powerful analytical tool for a wide range of scientific areas, especially studies on nanoscale phenomena and structural imaging in biology, materials science, and environmental science. We present here the property of the x-ray source, beamline design, and the operation and key optical components of the x-ray TXM. Plans to improve the throughput of the TXM will be discussed.