Lithium nitrite

Abstract: A semiflow batch reactor has been used to study the thermal decomposition of molten anhydrous lithium nitrate at 250, 300, and 350/sup 0/C. The gaseous products of decomposition from a thin quiescent layer of molten nitrate were swept out of the reactor by a steady flow of argon gas. Kinetic curves of both the gas phase and the molten phase were obtained. The observed rate of overall nitrite decomposition can be represented by a first-order rate equation with the following rate constants: k = (1.10 +- 0.05) x 10/sup -6/ sec/sup -1/ at 250/sup 0/C, k = (1.30 +- 0.07) x 10/sup -6/ sec/sup -1/ at 300/sup 0/C, and k = (1.25 +- 0.07) x 10/sup -6/ sec/sup -1/ at 350/sup 0/C. The complex overall stoichiometries of decomposition have been shown to be the sum of a combination of these individual steps. The conditions necessary for the stabilization of the mixture LiNO/sub 2/-LiNO/sub 3/-Li/sub 2/O have been identified. 20 refs.

Abstract: Electrolyte stability is an essential prerequisite for the successful development of a rechargeable organic electrolyte Li-O2 battery. Lithium nitrate (LiNO3) salt was employed in our previous work because it was capable of stabilizing a solid-electrolyte interphase on the Li anode. The byproduct of this process is lithium nitrite (LiNO2), the fate of which in a Li-O2 battery is unknown. In this work, we employ density functional theory and coupled-cluster calculations combined with an implicit solvation model for neutral molecules and a mixed cluster/continuum model for single ions to understand the chemical and electrochemical behavior of LiNO2 in acetonitrile (AN). The redox potentials of oxygenated nitrogen compounds predicted in this study are in excellent agreement with the experimental results (the average accuracy is 0.10 V). Theoretical calculations suggest that the reaction between the nitrite ion and its first oxidation product, nitrogen dioxide (NO2), in AN solution proceeds via the initial fo...

Abstract: The objective of this study is to clarify optimal conditions for suppressing the expansion of ASR-deteriorated concrete by pressure-injecting a lithium nitrite solution. To investigate the ASR-mitigating effect of lithium nitrite, concrete mixtures with two types of reactive aggregates were impregnated with lithium nitrite by pressurized injection at three steps of ASR. The effects of different timings on the penetration of lithium nitrite driven by the pressure gradient and on the suppression of expansion were examined through tests. The expansion rate started to decrease immediately after injecting a lithium nitrite solution into the concrete in the propagation period (PP) with severe ASR cracking and an expansion strain of 2000 micro. With a lithium-sodium molar ratio of 0.6 or more, further expansion was significantly reduced. On the other hand, expansion continued even after application of lithium nitrite when the solution was injected into the concrete in the early propagation period (EPP) with slight ASR cracking and an expansion strain of 400 micro, and the final strain eventually exceeded that of the concrete that had been subjected to the lithium injection in the PP. It is assumed that the lithium nitrite solution migrates through ASR cracks first because of the pressure gradient and then diffuses into the bulk mortar. The degree of expansion could also be affected by at which stage of ASR the lithium ions reach the reactive aggregates and the ASR gel.