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Optimization of the Synthesis of Combinatorial Samples

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Part of the Springer Theses book series (Springer Theses)

Abstract

Mechanisms for lithium loss during and after the formation of combinatorial samples of lithium nickel oxide were identified. During synthesis in air, the main source of lithium loss was the decomposition of lithium carbonate that failed to react with the nickel oxide structure. The fact that the formation of LiNiO2 was hindered significantly in air was attributed to the presence of constituents in air other than oxygen and nitrogen, the likeliest candidates being carbon dioxide and water vapor. The second mechanism for lithium loss was the thermal decomposition of Li\(_x\)Ni\(_{2-x}\)O2. TGA was used to confirm that both lithium oxide and oxygen were lost when the samples were heated in either air or oxygen. In both cases, the loss of lithium from the samples was attributed to the conversion of lithium oxide to lithium peroxide vapor. Synthesizing the samples in dry, carbon dioxide free air would therefore result in lithium content very close to that seen in oxygen, the only difference being attributed to a slight increase in the rate of decomposition of lithium nickel oxide as seen in the TGA. Combinatorial samples of Li\(_x\)Ni\(_{2-x}\)O2 cannot be made with x > 0.77 at 700 °C in air. In a flow of oxygen, excess lithium was used to react a sufficient amount of lithium into the material to form Li0.95Ni1.05O2 at 800 °C on an alumina substrate. These conditions allow the simultaneous synthesis of the layered and spinel structures in the Li–Mn–Ni–O system.

Keywords

Stearic Acid Nickel Oxide Ammonium Nitrate Rietveld Refinement Ammonium Bicarbonate 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Copyright information

© Springer International Publishing Switzerland 2014

Authors and Affiliations

  1. 1.Physics and Atmospheric Sciences Dept.Dalhousie UniversityHalifax, Nova ScotiaCanada

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