Study of Corrosion Resistance and Degradation Mechanisms in LiTiO2-Li2TiO3 Ceramic

Abstract

The interest in lithium-containing ceramics is due to their huge potential as blanket materials for thermonuclear reactors for the accumulation of tritium. However, an important factor in their use is the preservation of the stability of their strength and structural properties when under the influence of external factors that determine the time frame of their operation. This paper presents the results of a study that investigated the influence of the LiTiO2 phase on the increasing resistance to degradation and corrosion of Li2TiO3 ceramic when exposed to aggressive acidic media. Using the X-ray diffraction method, it was found that an increase in the concentration of LiClO4·3H2O during synthesis leads to the formation of a cubic LiTiO2 phase in the structure as a result of thermal sintering of the samples. During corrosion tests, it was found that the presence of the LiTiO2 phase leads to a decrease in the degradation rate in acidic media by 20–70%, depending on the concentration of the phase. At the same time, and in contrast to the samples of Li2TiO3 ceramics, for which the mechanisms of degradation during a long stay in aggressive media are accompanied by large mass losses, for the samples containing the LiTiO2 phase, the main degradation mechanism is pitting corrosion with the formation of pitting inclusions.

Unexplored Orthorhombic LiMn1–xTixO2 Cathode Materials with a Stable Atomic Site Occupancy and Phase Transition

“…Given that the crystal structure and transition-metal (Ti or Mn) oxidation state of m -Li 2 TiO 3 (β phase) are similar to those of m -Li 2 MnO 3 , we considered whether m -Li 2 TiO 3 could be formed as a secondary phase in o -LiMn 1– x Ti x O 2 ( x = 0.05, 0.1). However, according to the literature, c -Li 2 TiO 3 (γ phase) is more stable than m -Li 2 TiO 3 at high temperatures (≤1050 °C). , In addition, there are a significant number of oxygen vacancies in o -LiMn 1– x Ti x O 2 ( x = 0.05, 0.1), as confirmed by the previous Rietveld refinement analysis. Therefore, c -LiTiO 2 was preferred as a secondary phase in o -LiMn 1– x Ti x O 2 ( x = 0.05, 0.1) over m -Li 2 TiO 3 due to the partial loss of oxygen ions and preference for the cubic crystal structure during the synthesis (Figure c).…”

“…However, according to the literature, c-Li 2 TiO 3 (γ phase) is more stable than m-Li 2 TiO 3 at high temperatures (≤1050 °C). 56,57 In addition, there are a significant number of oxygen vacancies in o-LiMn 1−x Ti x O 2 (x = 0.05, 0.1), as confirmed by the previous Rietveld refinement analysis. Therefore, c-LiTiO 2 was preferred as a secondary phase in o-LiMn 1−x Ti x O 2 (x = 0.05, 0.1) over m-Li 2 TiO 3 due to the partial loss of oxygen ions and preference for the cubic crystal structure during the synthesis (Figure 3c).…”

Fluence of Phase Formation Processes in Lithium Zirconateceramics on Strengthand Thermal Properties

“…Based on the foregoing, the purpose of this work is to study the effect of the phase composition of Li 2 ZrO 3 ceramics obtained by solid-phase synthesis and annealed at different annealing temperatures in the range from 600 to 1100°C on the strength and thermophysical parameters of ceramics. This work is part of a cycle of works devoted to the study of the Li 2 ZrO 3 ceramic properties and evaluation of the possibility of their use as blanket materials for tritium propagation, which is one of the promising research areas in modern energy [18][19][20]. Li 2 ZrO 3 ceramics were chosen as objects of study, which, as was shown earlier in [18][19][20], are highly resistant to radiation damage.…”

“…This work is part of a cycle of works devoted to the study of the Li 2 ZrO 3 ceramic properties and evaluation of the possibility of their use as blanket materials for tritium propagation, which is one of the promising research areas in modern energy [18][19][20]. Li 2 ZrO 3 ceramics were chosen as objects of study, which, as was shown earlier in [18][19][20], are highly resistant to radiation damage.…”