NOVELTY - A metal hydride comprises manganese alkyl compound (I), where the metal hydride is capable of absorbing 14% hydrogen based on 100% total weight of the metal hydride without hydrogen storage.    USE - Metal hydride for propelling electric and/or hybrid vehicles, or storing electricity while connected to the electrical grid, and for use in storing material and storage system for storing hydrogen (all claimed) that is utilized in airplanes, homes, buildings, and barbeques. Can also be used as propellent for propelling an object, such as a jet or rocket.    ADVANTAGE - The metal hydride provides the material with better hydrogen storage performance.    DETAILED DESCRIPTION - A metal hydride comprises manganese alkyl compound of formula (Mn(M2)zHxRyLn), where the metal hydride is capable of absorbing 14% hydrogen based on 100% total weight of the metal hydride without hydrogen storage.    M2 = metals other than manganese, which have a total content of z;    R = organic group that does not contain beta-hydrogen substituent, preferably mesityl, neopentyl or trimethylsilylmethyl;    L = Lewis base;    n = 0-1;    x = 1.5-10;    y = 0-0.25; and    z = 0-1.    INDEPENDENT CLAIMS are also included for the following:    (1) a metal hydride storage material    (2) a method for preparing manganese alkyl compound of formula (MnRx1Yy1Ln), which involves reacting a manganese containing compound of formula (MnX2(dioxane)z1) with an alkyl alkali metal compound or an alkyl alkaline earth metal compound    (3) a metal hydride storage material comprising metal hydride    (4) a method for purifying a metal hydride, which involves subjecting metal hydride to hydrogen adsorption-desorption cycles    (5) a method for storing hydrogen, which involves providing a metal hydride, adding hydrogen to the metal hydride and allowing the hydrogen to coordinate to the metal hydride    (6) a storage system for a gas selected from hydrogen, methane and compressed natural gas comprising a storage system and a metal hydride within storage system, and for producing electricity using a fuel-cell or heat using an oxidant, comprising a storage system and a metal hydride within storage system.    Y = alkali metal or alkaline earth metal;    x1 = 1.8-2.2;    y1 = 0-0.2;    z1 = 1-2; and    X = halide.    DESCRIPTION OF DRAWING(S) - The drawing shows a storage system.    Storage system (10)    Tank body (12)    Metal hydride (14)    First passage (16)    First opening (18)    First valve (20)