Researchers have recently developed the world's first gas-solid hydride ion prototype battery (g-HIB), which uses hydrogen gas and a metal as the electrodes. The battery can not only power electrical equipment, but also enable highly efficient hydrogen storage under ambient temperature and pressure through an innovative hydrogen-electricity co-storage mechanism.
The research, led by Prof. CHEN Ping from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), was published in Joule in May.
Efficient hydrogen storage remains one of the most critical challenges limiting the widespread adoption of hydrogen energy technologies. Conventional approaches rely on extreme conditions—including high-pressure compression of up to 700 atmospheres or cryogenic liquefaction at −253 °C—resulting in high energy consumption, safety concerns, and increased system complexity. Developing a safe, efficient, and practical hydrogen storage technology that can operate under ambient conditions is therefore essential to the future hydrogen economy.
Hydride ions (H⁻), the electron-rich form of hydrogen, possess high reactivity and energy density, making them promising charge carriers for next-generation all-solid-state batteries. However, their inherent instability under ambient conditions has long hindered their practical application in electrochemical energy storage.
Since 2018, CHEN's team has focused on hydride ion conduction and developed a series of novel hydride ion electrolyte materials that enable stable hydride ion transport. In 2023 and 2025, the team reported the first low-temperature ultrafast hydride ion conductor and the first all-solid-state hydride ion prototype battery. Building on these advances, the researchers proposed the concept of a gas–solid hydride ion battery.
In this work, the team assembled the first g-HIB using magnesium metal and hydrogen gas respectively as the negative and positive electrode active materials. During discharge, hydrogen at the positive electrode is reduced to hydride ions, while magnesium at the negative electrode is oxidized and converted into magnesium hydride. The reverse process occurs during charging, allowing simultaneous hydrogen and electricity storage.
The battery exhibits a theoretical capacity higher than that of most known battery systems while integrating hydrogen storage functionality. Experimental results showed that during hydrogen charging, the battery delivered an initial discharge capacity as high as 1,526 mAh g⁻¹. When a voltage of 0.3 V was applied, approximately 6.0 wt% hydrogen (based on MgH₂ in the electrode) was released at room temperature. After 60 cycles, the capacity retention remained above 70%, and the battery operated stably across a wide temperature range from −20 °C to 90 °C.
Moreover, a tandem stack consisting of ten single cells generated an output voltage exceeding 2.4 V and powered an LED light, marking the birth of the gas–solid hydride ion prototype battery.
The team also demonstrated significant energy efficiency advantages over conventional thermal hydrogen storage technologies. In traditional Mg/MgH₂ thermal storage systems, hydrogenation releases substantial heat that must be dissipated, while dehydrogenation requires temperatures of around 300 °C. In contrast, the g-HIB converts the heat released during hydrogenation directly into electrical energy and uses electrical energy to drive hydrogen release. As a result, the overall energy efficiency reaches 93.9%—about one-third higher than that of conventional thermal hydrogen storage systems.
Researchers said the study established a new route to overcome one of the most persistent bottlenecks in hydrogen energy storage. By eliminating the need for extreme pressure or cryogenic conditions, the technology could pave the way for next-generation hydrogen storage systems.
For example, in hydrogen-powered drones, the g-HIB could serve as an efficient hydrogen supply module operating under ambient conditions while significantly extending flight endurance.
"Our future work will focus on developing higher-performance hydrideion conductors and electrode materials to further improve battery performance and accelerate the practical deployment of hydrideion battery technologies for hydrogen energy applications," CHEN said.
Joule
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A gas-solid hydride ion battery and a hydrogen-electricity co-storage system
13-May-2026