Editorial: Metal Hydride-Based Energy Storage and Conversion Materials

摘要

Energy storage and conversion materials are of critical importance in the development andutilization of new renewable clean energies (Li et al., 2016). Hydrogen, as an ideal energy carrierthat can be transportable, storable, and convertible, has the potential to become a solution toenergy security, resource availability, and environmental compatibility (Martin et al., 2020). Storinghydrogen in a safe, effective and economic way, however, is a great challenge in the developmentof a hydrogen-based economy, because of the extremely low volumetric density (0.0899 kg m?3) atambient condition (Schlapbach and Züttel, 2001). Compared to pressurizing gaseous or liquefyinghydrogen, storing hydrogen in metal hydride has definite advantages in terms of gravimetricand volumetric density, safety, and energy efficiency, for both mobile and stationary applications(Wu, 2008; He et al., 2019; Ouyang et al., 2020). Criteria developed by the US Department ofEnergy (DOE) for onboard hydrogen storage for light-duty fuel cell vehicles include 6.5 wt% ofsystematic gravimetric density and 50 kg H2 m?3 of volumetric density along with other stringentproperties such as operating temperature (85?C), extended cycle-life, fast kinetics, safety, andcost. Therefore, in the last decade tremendous efforts have been devoted to the research anddevelopment of light metal hydrides, including MgH2, alanates, borohydrides, amides/imides,which hold sufficiently high hydrogen capacity (Orimo et al., 2007; Hansen et al., 2016; Yu et al.,2017; Liu et al., 2018; Schneemann et al., 2018; Zhou et al., 2019; Hirscher et al., 2020).