Low-cost high-performance rare-earth-based AB5-type hydrogen storage alloy and preparation method thereof

The invention relates to a low-cost high-performance rare-earth-based AB5-type hydrogen storage alloy and a preparation method thereof. The alloy has a general formula: Ml(Ni(1-x-y-w)CoxMnyAlzMw)mMgn, wherein x, y, z, w, m and n present a mol ratio; x is larger than zero and smaller than or equal to 0.1; y is larger than zero and smaller than or equal to 0.2; z is larger than zero and smaller than or equal to 0.2; w is larger than or equal to zero and smaller than or equal to 0.06; m is larger than or equal to 4.8 and smaller than or equal to 5.5; n is larger than zero and smaller than or equal to 0.1; the Ml comprises La and at least one element selected from Ce, Pr, Nd, Sm, Gd, Dy, Y, Ca, Ti and Zr; the content of the La in the Ml is 40-80 percent by weight; accordingly, the content of the La in the alloy is 10-26 percent by weight; and the M comprises at least one element of Cu, Fe, Si, Ge, Sn, Cr, Zn, B, V, W, Mo Ta and Nb. The alloy has high content, long service life, low Co content, low cost and good recovery performance.