Low-Co AB5-type Mm(NiCoMnA1)5Bx (x = 0, 0.1, 0.2 ) electrode alloys were prepared by casting and rapid quenching.The effects of the rapid quenching on the lattice constants, microstructures and electrochemical characteristics of the alloys were investigated in detail.The obtained results show that the rapid quenching made lattice constants and cell volume increased.In a range of the quenching rate, rapid quenching can increase the discharge capacities of the alloys.However, the discharge capacity of the as-quenched alloy is lower than that of the as-cast alloy when quenching rate is more than a critical value.The cycle lives of the alloys increase monotonously with the increase of the quenching rate.