Researchers in Japan have developed a groundbreaking hydrogen battery that can operate at temperatures below 100°C, specifically around 90°C, which significantly lowers the temperature requirements compared to traditional hydrogen storage technologies. This new approach uses a solid electrolyte that transports hydride ions, allowing magnesium hydride (MgH2) at the battery’s anode to repeatedly absorb and release hydrogen gas at full theoretical capacity. This development promises a practical method for hydrogen storage, which could accelerate the adoption of hydrogen-powered vehicles and clean energy systems.
Conventional solid-state hydrogen storage methods rely on high temperatures—between 300 and 400°C—to release or absorb hydrogen, making them energy-intensive and unsuitable for daily applications. Alternative electrochemical storage methods using liquid electrolytes operate at lower temperatures but have struggled with poor hydrogen-ion transport, preventing them from reaching their theoretical hydrogen storage capacities. The Japanese team’s battery overcomes these issues by using a new solid electrolyte with an anti-α-AgI crystal structure that facilitates efficient hydride ion migration.
In this battery, magnesium hydride acts as the anode, and hydrogen gas acts as the cathode. During the charging process, magnesium hydride releases hydride ions that travel through the solid electrolyte and are converted into hydrogen gas at the cathode. When discharging, the process is reversed. Tests showed the battery achieved the full theoretical capacity of magnesium hydride storage—about 2,030 mAh per gram or 7.6% hydrogen by weight—over multiple cycles, a notable improvement over previous methods.
The significance of this technology lies in its potential to address long-standing challenges in hydrogen storage for clean energy. Traditional hydrogen storage faces hurdles such as the need for very low temperatures (-253°C) or very high pressures (350 to 700 bar), both of which pose safety, cost, and practical issues. Additionally, hydrogen embrittlement creates mechanical vulnerabilities in storage infrastructure. This new low-temperature, high-capacity, and reversible hydrogen storage system lays a foundation for more efficient, safe, and commercially viable hydrogen energy carriers, potentially enabling widespread use in vehicles and industries seeking carbon-free energy solutions.
This advancement marks an important step toward integrating hydrogen more broadly in the energy landscape, promising a future where hydrogen-powered technologies can be safer, more practical, and more efficient.
