Role of Rare-Earth Alloys in Lithium Borohydride Regeneration from Hydrous Lithium Metaborate

Lithium borohydride (LiBH4) is a promisinghydrogenstorage material, but the irreversibility of hydrolysis and the highcost of regeneration have severely restrained its commercial applications.Herein, we reported a cost-effective method to regenerate LiBH4 by ball milling hydrous lithium metaborate (LiBO2 center dot 2H(2)O) with low-cost Mg-based alloys, instead ofMgH(2), under ambient conditions. An effective strategy isdeveloped to improve the regeneration kinetics of LiBH4 by introducing the light rare-earth metals into Mg to facilitatethe breakage of B-O and conversion of H+ into H-. A yield of 40% can be achieved for a relatively shortball milling duration (10 h) for the LiBO2 center dot 2H(2)O-CeMg12 system. The optimized regeneration ofLiBH(4) is believed to be efficient and economical sinceit utilizes an intrinsic hydrogen source in LiBO2 center dot 2H(2)O and cheap reducing agents. Our finding is expected to enablea wide deployment of LiBH4 for hydrogen storage. We report a cost-effective way to regenerateLiBH(4) with fast kinetics by introducing the light rare-earthmetals intoMg.