A critical barrier to the wide-spread use of hydrogen is how to effectively store hydrogen for various energy applications. Chemical hydrogen storage in particular through the use of sodium borohydride (NaBH4) is a way to combine high energy density and ease of hydrogen release. These characteristics are essential for any near-term commercial opportunities of hydrogen power sources. Sodium borohydride is a white solid at room temperature, stable in dry air and decomposing only at temperatures above 400C. When mixed with water, NaBH4 gives off pure hydrogen gas. The reaction can be catalyzed in a number of ways to give the desired hydrogen flow rates to match electrical output demand at the fuel cell. The highly flammable hydrogen gas is only generated immediately before use, therefore it is a much safer way of storing hydrogen compared to compressed or liquefied hydrogen. NaBH4’s stability in air also makes it a much safer choice than its pyrophoric reversible metal hydride counterpart, particularly for consumer applications.
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