Facilitating the Systematic Nanoscale Study of Battery Materials by Atom Probe Tomography through in‐situ Metal Coating

Abstract

Through its capability for 3D mapping of Li at the nanoscale, atom probe tomography (APT) is poised to play a key role in understanding the microstructural degradation of lithium‐ion batteries (LIB) during successive charge‐ and discharge cycles. However, APT application to materials for LIB is plagued by the field induced delithiation (deintercalation) of Li‐ions during the analysis itself that prevents the precise assessment of the Li distribution. Here, we showcase how a thin Cr‐coating, in‐situ formed on APT specimens of NMC811 in the focused‐ion beam (FIB), preserves the sample’s integrity and circumvent this deleterious delithiation. Cr‐coated specimens demonstrated remarkable improvements in data quality and virtually eliminated premature specimen failures, allowing for more precise measurements via. improved statistics. Through improved data analysis, we reveal substantial cation fluctuations in commercial grade NMC811, including complete grains of LiMnO. The current methodology stands out for its simplicity and cost‐effectiveness and is a viable approach to prepare battery cathodes and anodes for systematic APT studies.

Understanding atom probe’s analytical performance for iron oxides using correlation histograms and ab initio calculations

“…This gives us more confidence to associate the third phase to partially reduced wüstite. Similar trends were observed when plotting the O + /O 2 + CSR against O level in figure 5(b) [46,47]. A comprehensive investigation of the various measurement parameters with theoretical dissociation reactions is imperative to guarantee measurement precision in APT analyses of oxide materials.…”

Unravelling Lithium Distribution in Carbon Fibre Electrodes for Structural Batteries with Atom Probe Tomography

“…The puck along with the clips was transferred under ultra-high vacuum by the suitcase. APT tips were prepared and coated with Cr [37,40]. In brief, a Cr lamella was lifted out, and a circular half-cut was introduced at a free edge (Fig.…”

“…Nevertheless, APT of materials containing Li is inherently challenging, as the electric field can drive Li migration [33][34][35][36]. Shielding the specimen with a thin layer of conductive metallic coating has been proposed and shown to prevent Li migration induced by electrostatic field penetration [35,[37][38][39].…”