Reactivity at the Electrode–Electrolyte Interfaces in Li-Ion and Gel Electrolyte Lithium Batteries for LiNi_0.6Mn_0.2Co_0.2O₂ with Different Particle Sizes

Abstract

The layered oxide LiNi0.6Mn0.2Co0.2O2 is a very attractive positive electrode material, as shown by the good reversible capacity, chemical stability, and cyclability upon long-range cycling in Li-ion batteries and, hopefully, in the near future, in all-solid-state batteries. Three samples with variable primary particle sizes of 240 nm, 810 nm, and 2.1 μm on average and very similar structures close to the ideal 2D layered structure (less than 2% Ni2+ ions in Li+ sites) were obtained by coprecipitation followed by a solid-state reaction at high temperatures. The electrochemical performances of the materials were evaluated in a conventional organic liquid electrolyte in Li-ion batteries and in a gel electrolyte in all-solid-state batteries. The positive electrode/electrolyte interface was analyzed by X-ray photoelectron spectroscopy to determine its composition and the extent of degradation of the lithium salt and the carbonate solvents after cycling, taking into account the changes in particle size of the positive electrode material and the nature of the electrolyte.

Unraveling the Morphological Dependency of the LiNi0.6Mn0.2Co0.2O2 Layered Oxide Reactivity in Li-Ion Batteries

“…% for the 870-5-air): it reveals the more pronounced LiPF 6 degradation at the surface of those thin platelets. In good agreement with one of our previous studies that studied the reactivity at the surface of NMC622-type samples depending on their particles’ size, this would be due to the larger specific surface area observed for the sample made of the thinnest platelets (12 m 2 /g vs less than 4 m 2 /g for the others) …”

“…In good agreement with one of our previous studies that studied the reactivity at the surface of NMC622-type samples depending on their particles' size, this would be due to the larger specific surface area observed for the sample made of the thinnest platelets (12 m 2 /g vs less than 4 m 2 /g for the others). 53 More carbonaceous species are found at the surface of the conventional particles at the end of discharge (38.2 at. % for the 870-5-air sample at 2.5 V vs 25.6 at.% and 22.3 at.…”

Self‐Assembled Surfactant‐Polyoxovanadate Soft Materials as Tuneable Vanadium Oxide Cathode Precursors for Lithium‐Ion Batteries

“…Larger crystallites intrinsically reduce the surface‐electrolyte exposure, with a higher proportion of V 2 O 5 being present in the protected bulk‐phase. Conversely, the smaller crystallite size, and therefore increased interfacial area, of the TBA‐V 2 O 5 material results in increased surface‐electrolyte exposure which enables more parasitic degradation [46] . The difference in the rate performance can be similarly rationalised, with the smaller TBA‐V 2 O 5 crystallites facilitating faster lithium insertion kinetics as a result of higher surface area and shorter bulk migration pathways compared to the nanostructured gem ‐V 2 O 5 material (Table S1) [16, 47] .…”

Gel Electrolyte for Li Metal Battery

“…If substituting them with gel polymer electrolyte, since the thickness of the gel polymers can be easily regulated as thin as a few microns, the energy density will be largely improved. Meanwhile, replacing the liquid electrolyte will greatly shorten the distance between the positive and negative electrodes, resulting in a smaller battery volume [15] …”

“…Meanwhile, replacing the liquid electrolyte will greatly shorten the distance between the positive and negative electrodes, resulting in a smaller battery volume. [15] Benefitted from the above impressive and attracting characteristics of the gel electrolyte, its application in the field of battery gains more attention and investigation. There have been some reviews introducing the related modification strategies and challenges for gel electrolyte and focused on the materials selection and structure design.…”