At Zhejiang University, researchers have cracked a problem that has stalled the hydrogen economy for years: how to store and release hydrogen reliably at room temperature, without burning through energy in the process. By engineering nanocomposites that pair ultrafine lithium borohydride particles with tiny 3-nanometer nickel clusters, Xin Zhang, Guenglin Xia and their colleagues have created a material that can absorb and release hydrogen at temperatures as low as 30°C — a breakthrough that could reshape how we power heavy-duty vehicles and store clean energy.
Hydrogen is widely seen as a cornerstone of a low-carbon future. Unlike fossil fuels, hydrogen fuel cells generate electricity directly from chemical energy without combustion, making them ideal for buses, trucks, trains and other vehicles too heavy for current battery technology. But hydrogen has a critical weakness: it's notoriously difficult to store safely and efficiently. Most hydrogen carriers — materials designed to absorb hydrogen and release it on demand — require extreme temperatures or pressures to work, consuming far more energy than they save.
Lithium borohydride (LiBH4) is one of the most promising hydrogen carriers known, capable of holding remarkably high amounts of hydrogen by weight. The catch is devilishly technical. When LiBH4 releases hydrogen through dehydrogenation, it splits into boron and lithium hydride (LiH). To reuse the material, those products need to recombine with hydrogen gas through a process called hydrogenation — but boron and LiH are extremely reluctant to do so. They resist this reaction stubbornly, requiring enormous amounts of energy to push the chemistry forward, making the entire cycle impractical.
Working across Zhejiang University and Fudan University, Zhang and Xia's team attacked the problem from first principles. Using theoretical calculations, they discovered that highly reactive surface boron atoms — which they termed "Bspike atoms" — are essential to forming new bonds between boron and hydrogen. More intriguingly, they found that smaller boron particles are far more hydrogenation-reactive than larger ones. As they explained in their paper published in Nature Nanotechnology, the proportion of these reactive Bspike atoms increases exponentially as boron clusters shrink to the ultrasmall scale.
Armed with this insight, the researchers synthesized nanocomposites that combine ultrafine LiBH4 nanoparticles with nickel clusters just 3 nanometers across. The nickel acts as a catalyst, performing two crucial functions simultaneously: it breaks hydrogen gas molecules apart into individual hydrogen atoms, and it chemically interacts with the boron clusters to weaken the bonds between boron atoms. This weakening is the key that unlocks hydrogenation at room temperature.
When these nanocomposites are dehydrogenated, the boron and lithium hydride clusters form at a 5–10 nanometer scale while the nickel clusters remain intact and reactive. Place the material under 100 bar of hydrogen pressure at just 30°C — barely warmer than a heated room — and hydrogenation proceeds smoothly, regenerating the original lithium borohydride so the cycle can repeat.
The implications are substantial. A hydrogen storage material that works reliably at room temperature could transform the economics of hydrogen transport and storage, removing one of the major barriers to a hydrogen-powered transportation network. With fuel cells poised to power the next generation of heavy-duty vehicles, breakthroughs like this one inch us closer to an energy system that doesn't depend on burning fossil fuels.