Advanced high-pressure metal hydride fabricated via Ti–Cr–Mn alloys for hybrid tank

• New non-stoichiometric Ti–Cr–Mn based alloys are prepared for the hybrid tank.
• (Ti0.85Zr0.15)1.1Cr0.9Mo0.1Mn has the best overall properties.
• The desorption pressure at 0 °C is 9.54 atm.
• The volumetric density of the hybrid system reaches 40 kg/m3.
• The gravimetric density remains as a high value of 2.72 wt%.

Ti–Cr–Mn-based alloys with a C14-type Laves structure have been investigated for potential application in hybrid high-pressure metal hydride tanks for fuel cell vehicles. The effects of partial substitution of Ti by Zr, and of Cr by Mo and W, on the hydrogen storage properties of Ti–Cr–Mn-based alloys have been systematically investigated. Among these alloys, (Ti0.85Zr0.15)1.1Cr0.9Mo0.1Mn shows the best overall properties, with a hydrogen desorption pressure and capacity of 9.54 atm and 1.78 wt% at 0 °C. The kinetics and cycling stability are also discussed for on-board hybrid high-pressure metal hydride tank applications. According to calculations, the volumetric H2 density of the hybrid system can reach the Department of Energy (DOE) 2017 target, while its gravimetric density remains at a high value of 2.72 wt% when 28% of the inner volume in a hybrid hydrogen metal hydride tank is filled with this alloy.