Enhanced hydrogen generation from hydrolysis of LiBH4 with diethyl ether addition for micro proton exchange membrane fuel cell application

LiBH4 has a high hydrogen storage capacity and could potentially serve as a superior hydrogen storage material. However, in its hydrolysis process, incomplete hydrolysis caused by the agglomeration of LiBH4 and its hydrolysis products limits its full utilization. In the present paper, a novel enhancement method to completely release the theoretical amount of hydrogen from LiBH4 hydrolysis is presented by the addition of diethyl ether. The results show that in the presence of diethyl ether, hydrolysis of LiBH4 can fully release 4 equivalents of hydrogen, and the agglomeration can be avoided. The enhanced performance can be attributed to the new phase LiBH4·[Et2O]x which is formed through the combination of LiBH4 with Et2O molecules. Hydrolysis of this new phase shows a complete hydrolysis process with a slow kinetics. The method discussed in this paper presents a novel strategy to enhance the hydrolysis of borohydrides and other hydrides that have the same agglomeration problems. LiBH4 diethyl ether suspension might be applied as a hydrogen generation source of micro proton exchange membrane fuel cells.

► Full hydrolysis of LiBH4 is achieved by the addition of Et2O. ► Agglomeration of LiBH4 is avoided by the addition of Et2O. ► The mechanism is the hydrolysis of LiBH4[Et2O]x intermediates. ► A fuel cell supplied by hydrolyzed LiBH4/Et2O can stably run for more than 3 h.