Li-Na ternary amidoborane for hydrogen storage: experimental and first-principles study

Li-Na ternary amidoborane, Na[Li(NH(2)BH(3))(2)], was recently synthesized by reacting LiH and NaH with NH(3)BH(3). This mixed-cation amidoborane shows improved dehydrogenation performance compared to that of single-cation amidoboranes, i.e., LiNH(2)BH(3) and NaNH(2)BH(3). In this paper, we synthesized the Li-Na ternary amidoborane by blending and re-crystallizing equivalent LiNH(2)BH(3) and NaNH(2)BH(3) in tetrahydrofuran (THF), and employed first-principles calculations and the special quasirandom structure (SQS) method to theoretically explore the likelihood for the existence of Li(1-x)Na(x)(NH(2)BH(3)) for various Li/Na ratios. The thermodynamic, electronic and phononic properties were investigated to understand the possible dehydrogenation mechanisms of Na[Li(NH(2)BH(3))(2)].