In response to the major national strategy of “carbon neutral”, developing the renewable secondary energy has become an important measure in China. However, how to realize the efficient storage and conversion of hydrogen and electric energy has been the bottleneck that restricts the large-scale application of secondary energy at present. The key is to find and develop the suitable lightweight carrier materials. Most borohydrides are ionic coordination compounds containing covalent bonds. They have high thermodynamics stability, ionic conductivity characteristics and are easy to undergo polymorphic transformation. Especially, their high temperature ionic conductivity is close to that of conventional liquid electrolytes. Moreover, due to the high content of hydrogen and hydrogen bonds, they can play multi-carrier roles in the storage and conversion of secondary energy. This review summarizes the functional applications of borohydride in solid-state hydrogen storage, hydrolytic hydrogen production, all-solid-state batteries and solar cells focousing on their preparation, microstructures and performance improvement mechanisms, which aims at clarifying the key problems and possible solutions in energy storage and conversion.