Lightweight metal halide and hydride fast Li ion conductors

This work was motivated by the extensive research on lithium solid state materials, which have attracted increasing interest for potential applications in hydrogen storage and/or lithium ion batteries due to their extraordinary properties. In this thesis, LiBH4-derived materials, LiInBr4 and complex phases based on lithium ammonia borane with potential use as solid state electrolytes were successfully synthesised and characterised

Phase behaviour in the LiBH4-LiBr system and structure of the anion-stabilised fast ionic, high temperature phase

The fast ionic, high temperature (HT) phase of LiBH4 can be stabilised by Br¯ substitution. Lithium borohydride bromide compounds, Li(BH4)1-xBrx have been synthesized mechanochemically, with and without thermal treatment and the resulting phase behaviour determined as a function of composition. Single phase materials exist for 0.29 ≤ x ≤ 0.50 with conductivity two orders of magnitude higher than LiBH4 at 313 K. Powder neutron diffraction has been used to resolve the details of the crystal structure of one such compound. These demonstrate that 7Li(11BD4)2/3Br1/3 retains the HT structure (hexagonal space group P63mc, a ≈ 4.2 Å, c ≈ 6.7 Å) from 293-573 K. The borohydride bromide exhibits considerable static and dynamic disorder, the latter invoking complex rotational motion of the (BH4)¯ anions

The Impact of International Remittances on Income, Work Efforts, Poverty and Inequality: Evidence from Vietnam

This study provides new empirical evidence on the impact of international remittances. Using data from the two most recent Vietnam Household and Living Standard Surveys, the paper estimates the effect of remittances on per capita income, per capita expenditure, work efforts, poverty and inequality. The estimates suggest that a rise in international remittances in Vietnam increases household income and expenditure. Yet, the study also finds evidence that international remittances may create a moral hazard problem by inducing disincentives to work. Moreover, the study suggests that international remittances, at the least in the short run, do not reduce poverty. They may even lead to an increase in inequality. Overall, the study casts doubts on the view that international remittances may play a crucial role in reducing poverty in developing countries

Phase Behavior in the LiBH₄–LiBr System and Structure of the Anion-Stabilized Fast Ionic, High Temperature Phase

The fast ionic, high temperature (HT) phase of LiBH₄ can be stabilized by Br¯ substitution. Lithium borohydride bromide compounds, Li­(BH₄)_1–<i>x</i>Br_<i>x</i>, have been synthesized mechanochemically, with and without thermal treatment and the resulting phase behavior determined as a function of composition. Single phase materials exist for 0.29 ≤ <i>x</i> ≤ 0.50 with conductivity 2 orders of magnitude higher than LiBH₄ at 313 K. Powder neutron diffraction has been used to resolve the details of the crystal structure of one such compound. These demonstrate that ⁷Li­(¹¹BD₄)_0.667Br_0.333 retains the HT structure (hexagonal space group <i>P</i>6₃<i>mc</i>, <i>a</i> ≈ 4.2 Å, <i>c</i> ≈ 6.7 Å) from 293 to 573 K. The borohydride bromide exhibits considerable static and dynamic disorder, the latter invoking complex rotational motion of the (BH₄)¯ anions