Hydrogen as an energy carrier is very versatile in energy storage applications. Developments in novel, sustainable technologies towards a CO₂-free society are needed and the exploration of all-solid-state batteries (ASSBs) as well as solid-state hydrogen storage applications based on metal hydrides can provide solutions for such technologies. However, there are still many technical challenges for both hydrogen storage material and ASSBs related to designing low-cost materials with low-environmental impact. The current materials considered for all-solid-state batteries should have high conductivities for Na⁺, Mg²⁺ and Ca²⁺, while Al³⁺-based compounds are often marginalised due to the lack of suitable electrode and electrolyte materials. In hydrogen storage materials, the sluggish kinetic behaviour of solid-state hydride materials is one of the key constraints that limit their practical uses. Therefore, it is necessary to overcome the kinetic issues of hydride materials before discussing and considering them on the system level. This review summarizes the achievements of the Marie Skłodowska-Curie Actions (MSCA) innovative training network (ITN) ECOSTORE, the aim of which was the investigation of different aspects of (complex) metal hydride materials. Advances in battery and hydrogen storage materials for the efficient and compact storage of renewable energy production are discussed.

A variety of transition metal binary compounds, whose reaction mechanism involves intercalation-initiated conversion, have been extensively studied as anode materials in lithium ion batteries (LIBs). Although the introduction of carbonaceous materials such as carbon nanotubes, graphene, or a carbon layer solved issues arising from the conversion reaction during repetitive cycles, a perfect electrical contact of the carbonaceous material with the discharge products on a few-nanometer scale has been rarely accomplished. Moreover, most of the previous studies have focused on maximizing the electrochemical performance without an in-depth understanding of the fundamental effect of each component in the nanocomposite. Herein, an ordered mesoporous tungsten oxide/carbon composite with ultra-highly dispersed carbon over a few-nanometer scale is prepared by the self-assembly of a block copolymer with inorganic/carbon precursors. The confinement effect of tungsten oxide within the nanowalls (∼10 nm) is comprehensively investigated by electrochemical transient analysis and various ex situ analytic methods including X-ray diffraction and X-ray absorption spectroscopy. The resulting electrode provides an excellent cycle and rate performance owing to the highly conductive and stable matrix that endures repetitive conversion reactions.