NaAlH4 nanoconfinement in a mesoporous carbon for application in lithium ion batteries

Alanates have recently attracted attention as new anodic materials for lithium ion batteries. The electrochemical activity of sodium alanate has been already reported and the conversion mechanism explained. Through a complex conversion reaction, this compound is able to develop almost all the theoretical capacity, achieving more than 1700 mAh/g upon first discharge with an efficiency of 70%. Nevertheless alanate undergoes to capacity fade in few cycles. This is mainly due to the severe structural reorganization following the conversion reaction, that results in electrode pulverization and loss of electric contact. Here, we present a nanocomposite material consisting of NaAlH4 confined in the nanoporous of a carbon matrix able to mitigate the effect of volume expansion and improve the cyclability. Specifically, the nanocomposite has been studied in terms of structure, morphology and hydrogen content by the means of Infrared Spectroscopy, solid state NMR, electronic microscopy and thermal analysis. Finally, its performance in lithium cells is presented.