Sodium tetrahydroborate as energy/hydrogen carrier, its history

Sodium tetrahydroborate NaBH₄ is considered as being a promising energy/hydrogen carrier. NaBH₄ is not a new compound. It has been discovered in 1940s by Prof. H.C. Brown, Nobel Laureate in Chemistry in 1979. NaBH₄ has thus a history and this history distinguishes the NaBH₄ utilisation as hydrogen carrier from that as energy carrier. In fact, the history of NaBH₄ (for both utilisations) can be divided into three periods, each period being characterised by specific societal challenges. Whereas during the first period the challenges were military and political, the challenges in the third period (i.e. at present) are energetic, environmental, civilian, social and political. The second period was rather calm for NaBH₄ even if it was intensively used as a reducing agent in organic chemistry.