Back to Blog
Sodium nmc cathode xps7/22/2023 Finally, we confirmed the complete conversion of similar to 7 nm ALD Li 2CO 3 films on silicon from HFPy exposure using XPS and spectroscopic ellipsometry. Scanning transmission electron microscopy, X-ray energy dispersive spectroscopy, and XPS measurements following HFPy exposure to Li 2CO 3 powder revealed the formation of a conformal LiF shell around the Li 2CO 3 particles. This conversion is desirable given that Li 2CO 3 degrades LIB performance, whereas LiF provides an excellent physio-chemical barrier against chemical attack during cycling. We found a decrease in surface carbonate and an increase in surface fluoride after HFPy exposure suggesting the conversion of lithium carbonate (Li 2CO 3) to lithium fluoride (LiF). This paper uses X-ray photoelectron spectroscopy (XPS) measurements to elucidate the surface chemical changes on LIB cathode material surfaces upon exposure to the ALD metal fluoride precursor, more » hydrogen fluorine pyridine (HFPy). Although numerous studies have demonstrated the benefit of ALD metal fluoride coatings to LIB performance, comparatively few works have examined the effect of individual ALD precursors on the cathode surface. Atomic layer deposition (ALD) is an effective method to deposit ultrathin metal fluoride coatings on LIB cathodes. Herein, ultrathin metal-fluoride barrier coatings on the surface of lithium-ion battery (LIB) cathodes can improve cycling stability and prevent corrosion by acidic byproducts in the electrolyte. The ability to chemically modify the surface of cathode materials via vapor-phase precursor adsorption will open new avenues to systematically control the interface of the cathode materials in LIBs that are not possible by conventional coating = , The XPS measurements reveal that the transition metals in the cathode materials undergo selective oxidation/reduction depending upon the nature of the precursor, the coating, and the cathode material. LiNi xMn 1-x-圜o yO 2, NMC), was studied via X-ray photoelectron spectroscopy (XPS). NiO and MnO) to complex multi-element cathode materials (e.g. Here, the surface composition of these cathode materials, which range from simple transition metal oxides (e.g. ![]() This paper describes a systematic investigation to understand the interfacial changes of 12 different cathode materials upon coating with aluminum oxide (Al 2O 3) using trimethyl aluminum (TMA) and H 2O, and aluminum fluoride (AlF 3) using TMA and hydrogen fluoride pyridine (HFPy). While there have been numerous reports evaluating the electrochemical performance of these surface-modified cathode materials, the chemical changes induced on the surface of the cathode materials upon ALD coating are not fully studied. Atomic layer deposition (ALD) has emerged as a promising technology for applying ultrathin protective coatings on lithium-ion battery (LIB) cathode surfaces to improve their cycling stability.
0 Comments
Read More
Leave a Reply. |