Reaction of LiD with moisture by temperature programmed reaction (TPR)

The temperature programmed reaction technique was performed on LiOH powders and LiD single crystals previously exposed to different moisture levels. Our results show that the LiOH decomposition process has an activation energy barrier of 30 to 33.1 kcal/mol. The LiOH structure is stable at 320 K for 100 years. However, LiOH structures formed on the surface of LiD during moisture exposure at low dosages may have multiple activation energy barriers, some of which may be much lower than 30 kcal/mol. We attribute the lowering of the activation energy barrier for the LiOH decomposition to the existence of dangling bonds, cracks, and other long range disorders in the LiOH structures formed at low levels of moisture exposure. These defective LiOH structures may decompose significantly over the next 100 years of storage even at room temperature. At high moisture exposure levels, LiOH.H2O formation is observed. The release of H2O molecules from LiOH.H2O structure has small activation energy barriers in the range of 13.8 kcal/mol to 16.0 kcal/mol. The loosely bonded H2O molecules in the LiOH.H2O structure can be easily pumped away at room temperature in a reasonable amount of time. Our experiments also suggest that handling LiD single crystals at an elevated temperature of 340 K or more reduces the growth of LiOH and LiOH.H2O significantly