Recently, a team from the Dalian Institute of Chemical Physics (hereinafter referred to as "DICP"), Chinese Academy of Sciences, achieved a major technological breakthrough by successfully constructing the world's first gas-solid hydride ion prototype battery (hereinafter referred to as "gas-solid battery") using hydrogen gas and metal as electrodes. The battery adopts a "hydrogen-electricity co-storage" mode, enabling charging with hydrogen and discharging electricity, as well as charging with electricity and releasing hydrogen, providing a practical prototype verification for efficient hydrogen storage under ambient temperature and pressure conditions, and solving a long-standing core challenge in the field of hydrogen energy utilization.
It is reported that hydride ions are the "electron-rich" state of hydrogen. As charge carriers, they possess the notable characteristics of high reactivity and high energy, and are considered one of the key pathways for developing next-generation all-solid-state batteries. However, hydride ions are extremely unstable under natural conditions, a property that makes it difficult for scientists to directly apply them in electrochemical energy storage, constituting a bottleneck constraining the development of related technologies.
To overcome this technological bottleneck, the DICP team innovatively designed a system using magnesium metal and hydrogen gas as the anode and cathode active materials respectively, successfully assembling the world's first gas-solid hydride ion battery capable of operating across a wide temperature range. The core advantage of this battery lies in enabling hydride ions to provide high energy for the battery while achieving an ingenious integration with electrochemical hydrogen storage: during discharge, hydrogen gas is reduced to hydride ions at the cathode, while the metal is oxidized to cations at the anode to form metal hydrides; during charging, the two electrodes respectively release hydrogen molecules and regenerate metal, truly realizing the synergistic effect of simultaneous charging/discharging and hydrogen storage/release.
Experimental data show that the gas-solid battery demonstrates excellent performance: in the hydrogen-charged state, the initial discharge capacity reaches as high as 1,526 mAh/g; when a voltage of 0.3 V is applied, approximately 6.0 wt% hydrogen (calculated based on MgH₂ in the electrode) can be released at room temperature; after 60 cycles, the capacity retention rate still exceeds 70%, and the battery can operate stably across a wide temperature range from as low as -20°C to as high as 90°C. Furthermore, the team stacked 10 single cells into a series-connected battery pack with an output voltage exceeding 2.4 V, successfully lighting up an LED bulb, marking the official debut of the gas-solid hydride ion prototype battery. Energy efficiency analysis further indicates that the energy utilization efficiency of this "hydrogen-electricity co-storage" system can reach 93.9%, representing a one-third improvement over conventional thermal hydrogen storage methods.
This original achievement is of great significance, providing an entirely new technical route for solving the hydrogen storage challenge that has persisted in the hydrogen energy utilization field for over half a century. It completely eliminates the extreme conditions required by traditional hydrogen storage, such as high pressure (700 atm) or cryogenic temperatures (-253°C), and is expected to give rise to new-type hydrogen storage technologies, clearing key obstacles for the large-scale development of the hydrogen energy industry.
Looking ahead, the DICP team stated that it will continue to focus on core technology breakthroughs, concentrating R&D efforts on higher performance hydride ion conductors and electrode materials, continuously improving overall battery performance, developing proprietary core technologies, accelerating the practical application of hydride ion batteries, and injecting new momentum into the high-quality development of the global hydrogen energy industry.
