Enhancing Hydrogen Storage Kinetics and Cycling Properties of NaMgH3 by 2D Transition Metal Carbide MXene Ti3C2

Abstract

Metal hydrides have recently been proposed for not only hydrogen storage materials but also high-efficiency thermal storage materials. NaMgH3 contains a considerable theoretical thermal storage density of 2881 kJ/kg. However, its sluggish de/re-hydrogenation reaction kinetics and poor cycling stability exhibit unavailable energy efficiency. Doping with active catalyst into NaMgH3 is deemed to be a potential strategy to mitigate these disadvantages. In this work, the enhancement of de/re-hydrogenation kinetics and cycling properties of NaMgH3 is investigated by doping with lamellar-structure 2D carbon-based MXene, Ti3C2. Results shows that introducing 7 wt.% Ti3C2 is proved to perform excellent catalytic efficiency for NaMgH3, dramatically reducing the two-step hydrogen desorption peak temperatures (324.8 and 345.3 °C) and enhancing the de/re-hydrogenation kinetic properties with the hydrogen desorption capacity of 4.8 wt.% H2 within 15 min at 365 °C and absorption capacity of 3.5 wt.% H2 within 6 s. Further microstructure analyses reveal that the unique lamellar-structure of Ti3C2 can separate the agglomerated NaMgH3 particles homogeneously and decrease the energy barriers of two-step reaction of NaMgH3 (114.08 and 139.40 kJ/mol). Especially, lamellar-structure Ti3C2 can improve the reversibility of hydrogen storage of NaMgH3, rendering 4.6 wt.% H2 capacity remained after five cycles. The thermal storage density of the composite is determined to be 2562 kJ/kg through DSC profiles, which is suitable for thermal energy storage application.

A review on MOFs synthesis and effect of their structural characteristics for hydrogen adsorption

“…Among these groups of materials, metal hydrides are the most attractive candidates due to their ability to achieve relatively high volumetric density. 30,[36][37][38] However, the gravimetric capacity does not meet the set target by DOE. 24 Moreover, metal hydride suffers from poor kinetics opting for charging time longer than the DOE target, 24 and requires high temperature for adsorption/desorption.…”

Mixed-dimensional nanocomposites based on 2D materials for hydrogen storage and CO2 capture

“…This has been achieved by incorporating nanoparticles into MXene. In a study by Hang et al 95 , perovskite hydride (NaMgH 3 ) was introduced into the layers of 2D MXene. It has been observed that the presence of lamellar structures within the 2D MXene demonstrates the feasibility of achieving reversible hydrogen storage capacity (approximately 4.6 wt%) after five cycles.…”

Recent Progress Using Solid-State Materials for Hydrogen Storage: A Short Review

“…This technique has been spotlighted due to its high storage density, remarkable stability, and small space occupancy [33][34][35][36]. A number of metal hydride vessels have been developed [37][38][39]. NaAlH 4 , LiAlH 4 , LiBH 4 , NaBH 4 , and AlH 3 are used as metal hydrogen storage materials; in particular, Mg 2 NiH 4 is in the limelight because of its advantages, such as its high storage capacity, low cost, and light weight [40].…”