High capacity, high efficiency and resource-rich energy storage systems are required to store large scale excess electrical energy from renewable energy. We proposed "Hybrid Nickel-Metal Hydride/Hydrogen (Ni-MH/H-2) Battery" using high capacity AB(5)-type hydrogen storage alloy and high-pressure H-2 gas as negative electrode active materials. It was experimentally confirmed that hydrogen gas can be utilized as an active material of negative electrode by the presence of the AB(5)-type hydrogen storage alloy. The experimental average cell voltage suggested that H-2 gas passed through the alloy in the form of atoms. The calculated gravimetric energy density of this hybrid battery increased up to 1.5 times of the conventional Ni-MH battery with low content of rare-earth element which is 32 wt% of the Ni-MH battery. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.