Combined use of EPR and (23)Na MAS NMR spectroscopy for assessing the properties of the mixed cobalt-nickel-manganese layers of P3-NayCo1-2xNixMnxO2.

Title Combined use of EPR and (23)Na MAS NMR spectroscopy for assessing the properties of the mixed cobalt-nickel-manganese layers of P3-NayCo1-2xNixMnxO2.
Authors M. Kalapsazova; S. Ivanova; R. Kukeva; S. Simova; S. Wegner; E. Zhecheva; R. Stoyanova
Journal Phys Chem Chem Phys
DOI 10.1039/c7cp04849a
Abstract

Knowledge on the formation of mixed transition metal layers on lithium and sodium transition metal oxides, Li/Na(Co,Ni,Mn,)O2, determines the ability to control their electrochemical properties as electrode materials in alkaline ion batteries. Taking this into account, herein we combine the EPR and (23)Na MAS NMR spectroscopic techniques to gain insights into the structural peculiarities of the mixed cobalt-nickel-manganese layers of NayCo1-2xNixMnxO2 with a three-layer stacking (P3-type) structure. Two types of compositions are examined where diamagnetic Co(3+) and paramagnetic Ni(3+) and Mn(4+) are stabilized: Na2/3Co1/3Ni1/3Mn1/3O2 and Na1/2Ni1/2Mn1/2O2. EPR spectroscopy operating in the X- and Q-band region is applied with an aim to improve the spectra resolution and, on the other hand, to provide straightforward information on the coordination of the transition metal ions inside the layers. The analysis of EPR spectra is based on the reference for the Mn(4+) and Ni(2+) ions occurring simultaneously in oxides with two layer stacking, P2-Na2/3Ni1/3Mn2/3O2. Complementary to EPR, (23)Na MAS NMR spectroscopy at high spinning rates is undertaken to assess the local structure of the Na nucleus in the layered P3-NayCo1-2xNixMnxO2 oxides. All results are discussed taking into account the EPR and NMR data for the well-known lithium analogues O3-LiCo1/3Ni1/3Mn1/3O2 and O3-LiNi1/2Mn1/2O2. Finally, the structure peculiarities of the transition metal layers extracted from the EPR and NMR methods are demonstrated by electrochemical intercalation of Li(+) ions into P3-NayCo1-2xNixMnxO2.

Citation M. Kalapsazova; S. Ivanova; R. Kukeva; S. Simova; S. Wegner; E. Zhecheva; R. Stoyanova.Combined use of EPR and (23)Na MAS NMR spectroscopy for assessing the properties of the mixed cobalt-nickel-manganese layers of P3-NayCo1-2xNixMnxO2.. Phys Chem Chem Phys. 2017. doi:10.1039/c7cp04849a

Related Elements

Cobalt

See more Cobalt products. Cobalt (atomic symbol: Co, atomic number: 27) is a Block D, Group 9, Period 4 element with an atomic weight of 58.933195. Cobalt Bohr ModelThe number of electrons in each of cobalt's shells is 2, 8, 15, 2 and its electron configuration is [Ar]3d7 4s2. The cobalt atom has a radius of 125 pm and a Van der Waals radius of 192 pm. Cobalt was first discovered by George Brandt in 1732. In its elemental form, cobalt has a lustrous gray appearance. Cobalt is found in cobaltite, erythrite, glaucodot and skutterudite ores. Elemental CobaltCobalt produces brilliant blue pigments which have been used since ancient times to color paint and glass. Cobalt is a ferromagnetic metal and is used primarily in the production of magnetic and high-strength superalloys. Co-60, a commercially important radioisotope, is useful as a radioactive tracer and gamma ray source. The origin of the word Cobalt comes from the German word "Kobalt" or "Kobold," which translates as "goblin," "elf" or "evil spirit.

Manganese

See more Manganese products. Manganese (atomic symbol: Mn, atomic number: 25) is a Block D, Group 7, Period 4 element with an atomic weight of 54.938045. Manganese Bohr ModelThe number of electrons in each of Manganese's shells is [2, 8, 13, 2] and its electron configuration is [Ar] 3d5 4s2. The manganese atom has a radius of 127 pm and a Van der Waals radius of 197 pm. Manganese was first discovered by Torbern Olof Bergman in 1770 and first isolated by Johann Gottlieb Gahn in 1774. In its elemental form, manganese has a silvery metallic appearance. Elemental ManganeseIt is a paramagnetic metal that oxidizes easily in addition to being very hard and brittle. Manganese is found as a free element in nature and also in the minerals pyrolusite, braunite, psilomelane, and rhodochrosite. The name Manganese originates from the Latin word mangnes, meaning "magnet."

Nickel

See more Nickel products. Nickel (atomic symbol: Ni, atomic number: 28) is a Block D, Group 4, Period 4 element with an atomic weight of 58.6934. Nickel Bohr ModelThe number of electrons in each of nickel's shells is [2, 8, 16, 2] and its electron configuration is [Ar]3d8 4s2. Nickel was first discovered by Alex Constedt in 1751. The nickel atom has a radius of 124 pm and a Van der Waals radius of 184 pm. In its elemental form, nickel has a lustrous metallic silver appearance. Nickel is a hard and ductile transition metal that is considered corrosion-resistant because of its slow rate of oxidation. Elemental NickelIt is one of four elements that are ferromagnetic and is used in the production of various type of magnets for commercial use. Nickel is sometimes found free in nature but is more commonly found in ores. The bulk of mined nickel comes from laterite and magmatic sulfide ores. The name originates from the German word kupfernickel, which means "false copper" from the illusory copper color of the ore.

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