Development of Ti0.85Zr0.17(Cr-Mn-V)1.3Fe0.7-based Laves phase alloys for thermal hydrogen compression at mild operating temperatures

Self Cite

Three series of alloys, Ti 0.92 Zr 0.10 Cr 1.7−x Mn 0.3 Fe x (x = 0.2−0.4), Ti 0.92 Zr 0.10 Cr 1.6−y Mn y Fe 0.4 (y = 0.1−0.7), and Ti 0.92+z Zr 0.10−z Cr 1.3 Mn 0.3 Fe 0.4 (z = 0, 0.015, 0.04), were prepared by induction levitation melting for a metal hydride hydrogen compressor from 8 to 20 MPa at water-bath temperature, with investigation on their crystal structural characteristics and hydrogen storage properties. The results show that a single C14-Laves phase with homogeneous element distribution exists in all of the alloys. The hydrogen ab-/ desorption plateau of the alloys is increased as the Fe, Mn, or Ti content increases due to decrement of the interstitial site radius originated from the respective atomic size. The hydrogen storage capacity of the alloys also correlates negatively with the hydrogen affinity of interstitial sites due to the influence of the element electronegativity. In a comprehensive consideration of the hydrogen storage performance for application, the Ti 0.935 Zr 0.085 Cr 1.3 Mn 0.3 Fe 0.4 alloy shows saturated hydrogenation under 8 MPa at 293 K and dehydrogenation around 24.91 MPa pressure at 363 K with a hydrogen capacity of 1.74 wt %, as well as excellent cycling performance and mere hysteresis. The Ti 0.92 Zr 0.10 Cr 1.0 Mn 0.6 Fe 0.4 alloy is another promising candidate with a remarkable hydrogen capacity of 1.86 wt % at 283 K and a dehydrogenation pressure of 27.94 MPa at 363 K, together with a satisfactory cycling durability. This study can guide the compositional design of AB 2 -type hydrogen storage alloys for hydrogen compression application.

Section: ■ Results and Discussionmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Development of (Ti–Zr)_1.02(Cr–Mn–Fe)₂-Based Alloys toward Excellent Hydrogen Compression Performance in Water-Bath Environments

Cao

Piao

Xiao

et al. 2023

Self Cite

“…This enlarges the thermodynamic difference among the interstitials and generates a consequent slope increment, according to Ivey et al 37 It is similar to the effects of increased element content with high hydrogen affinity in hydrogen storage alloys such as V 54 or rare earth element 55 substitution. 26 Although the alloy bulk modulus can be increased due to the higher bulk modulus of Nb than Ti (105 GPa), 47 this seems a subordinate factor for pressure escalation because a similar paradoxical pressure increment is also achieved by Charbonnier et al, 56 as well as with Mn or Fe substitution for Cr, 18,30 whose respective bulk moduli are 60 and 155 GPa, both lower than that of Cr. 47 Nevertheless, hydrogen affinity of alloy elements is another major factor that essentially modifies hydrogen storage performance 49 apart from size and bulk modulus effect.…”

Section: Average R a D I U S R A T I O O F T H E A / B -S I D E A T O...mentioning

confidence: 90%

“…For instance, in the investigations performed by Zhou et al, the decreased plateau hysteresis of Ti–Mn-based alloys exhibits a clear correlation to descending plateau pressure as well as ascending unit cell volume, consistent with the machine learning results . Also in experimental research performed by Cao et al, , Ti–Zr–(V)–Cr–Mn–Fe-based alloys exhibit increased plateau pressure, deteriorating hysteresis, and decreased interstitial size simultaneously as the mount of Mn or Fe substitution for Cr is increased. Therefore, according to relevant reports, the hysteresis-pressure characteristic of AB 2 -type alloys is a universal obstacle to MHHC development with higher pressure requirements.…”

Section: Introductionmentioning

confidence: 99%

Experimental and Theoretical Investigation on the Enhanced Hydrogen Storage Performance of Ti–Cr–Mn–Fe-Based Alloys Modified by Nb Substitution

Cao,

Zhou,

Xiao

et al. 2024

Self Cite

= 0, 0.02, 0.05, and 0.08) alloys were prepared through induction levitation melting, and their crystal structure characteristics and hydrogen storage properties were investigated by experiments and first-principles calculations. The alloys exhibit a main C14-Laves phase with fine element homogeneity and minor oxides. As the Nb stoichiometry in Ti 1.02 Nb x Cr 1.0−x Mn 0.6 Fe 0.4 (x = 0−0.05) alloys increases, the alloy exhibits enhanced hydrogen absorption/desorption kinetics and capacity, despite an increased plateau slope due to improved hydrogen affinity. The Ti 1.02−y Nb y Cr 1.0 Mn 0.6 Fe 0.4 (y = 0−0.08) alloys show simultaneous hysteresis amelioration and plateau pressure increment as the Nb content increases, thanks to hydride destabilization and expanded interstitials. The effects can be attributed to the medium atomic size and hydrogen affinity of Nb. Moreover, the first-principles calculation results indicate preferential occupancy at 4f sites of Nb in Ti−Cr−Mn−Fe-based alloys, and an expanded crystal lattice can be achieved with Nb substitution for Cr or Ti. This work shows that Nb substitution can be a promising strategy for the hydrogen storage performance enhancement of Ti−Cr-based Laves phase alloys for hydrogen compression applications.

“…Alternatively, chemical storage like metal hydrides, , nanomaterials, , graphene materials, , and organic compounds , are being developed. Among them, promising room-temperature hydrogen storage alloys such as LaNi 5 , TiMn 2 , , TiFe, LaMgNi, − and body-centered cubic (BCC)-type alloys − have emerged for both stationary and mobile applications. These materials overcome the limitations of compressed gas or liquid hydrogen, offering advantages such as safety, low compression energy consumption, high volume storage density, and ease of operation.…”

Section: Introductionmentioning

confidence: 99%

Development of V-Free BCC Structured Alloys for Hydrogen Storage

Hu,

Tang,

Xiao

et al. 2023

V-free body-centered cubic (BCC) structured hydrogen storage alloys have gained significant attention for their low cost and high theoretical hydrogen storage capacity (3.8 wt %). However, before practical application, critical challenges, such as low dehydriding capacity, activation difficulty, and poor cyclic stability, need to be solved. In this work, an easily activated and high-performance V-free BCC-type alloy (Ti40Cr50Mo10Ce1) was successfully synthesized by heat treatment and Ce doping. The heat treatment significantly increased its dehydriding capacity to 2.5 wt %, attributed to a reduced slope factor (0.76–0.17), making it comparable to V-based BCC-type alloys. And the V-free BCC-type alloy, after Ce doping, enabled room-temperature hydrogen absorption, eliminating the need for high-temperature activation. Ce doping did not significantly affect the activation energy, enthalpy change, or hysteresis factor of the alloy during de/hydrogenation. Additionally, the V-free BCC-type alloy, after heat treatment and Ce doping, exhibited excellent cyclic stability, with a capacity retention rate of 90% after 100 cycles. This study provides valuable guidance for designing innovative and cost-effective hydrogen storage alloys.