Structure and Thermal Properties of Composites with RE-Borohydrides (RE: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Er, Yb or Lu) and LiBH 4. -Mechanochemical milling of LnCl 3 (Ln: La-Tb, Er, Yb, Lu) with LiBH4 in the molar ratio of 1:6 for 5 h and additional annealing at 100 C for 50 h leads to the new compounds LiLn(BH4)3Cl (Ln: La, Ce, Pr, Nd, Sm, Gd), Ln(BH 4)3 (Ln: Sm, Gd, Tb, Er, Yb), and/or LiLn(BH4)4 (Ln: Yb, Lu). The products are characterized by powder XRD, IR spectroscopy, hydrogen sorption measurements, and thermogravimetric analysis. LiLn(BH 4)3Cl (Ln: La, Ce, Pr, Nd) crystallize in the cubic space group I43m. Ln(BH4)3 (Ln: Sm, Gd, Tb, Er, Yb) phases crystallize in the cubic space group Pa3, with a possible polymorphic transition to the space group Pm3m. Yb and Lu form tetrahedral [Ln(BH4)4]complexes stabilized by Li + cations crystallizing in the tetragonal space group P42c. Hydrogen desorption from the composite mixtures starts around 200 C. Rehydrogenation of the La-system under 10 MPa H 2 at 300 C shows partial reversibility. -(OLSEN, J. E.; FROMMEN, C.; JENSEN, T. R.; RIKTOR, M. D.; SOERBY, M. H.; HAUBACK*, B. C.; RSC Adv. 4 (2014) 4, 1570-1582, http://dx.