MgH2 electrochemical conversion reaction is a valuable alternative to Li intercalation into graphite for next generation Li-ion cells [1]. MgH2 has a theoretical capacity of 2048 mAhg-1, 5 times larger than of graphite. The incorporation of lithium occurs by the reduction of magnesium hydride to magnesium metal nanoparticles surrounded by an amorphous matrix of lithium hydride [1,2] (hydride conversion reaction, HCR). “Going-nano” plays a key role in the promotion of the MgH2 HCR. This last effect can be thermodynamic and/or kinetic as it may involve variation of the chemical potentials of nanophases as well as drastic improvements in the ion diffusivity. It is well known that the reduction of MgH2 particle size to the nanoscale promotes the hydrogen release at moderate temperatures by tuning up the desorption thermodynamics [3]. It is likely that similar effects play a role also in the case of room temperature HCR processes in Li-cells. In this communication we discuss our recent results about the MgH2 conversion reaction in a lithium cell. Our study combines computational and experimental efforts in order to derive a comprehensive picture of the MgH2 HCR
The MgH2 conversion reaction in a lithium cell
BRUTTI, SERGIO
2013-01-01
Abstract
MgH2 electrochemical conversion reaction is a valuable alternative to Li intercalation into graphite for next generation Li-ion cells [1]. MgH2 has a theoretical capacity of 2048 mAhg-1, 5 times larger than of graphite. The incorporation of lithium occurs by the reduction of magnesium hydride to magnesium metal nanoparticles surrounded by an amorphous matrix of lithium hydride [1,2] (hydride conversion reaction, HCR). “Going-nano” plays a key role in the promotion of the MgH2 HCR. This last effect can be thermodynamic and/or kinetic as it may involve variation of the chemical potentials of nanophases as well as drastic improvements in the ion diffusivity. It is well known that the reduction of MgH2 particle size to the nanoscale promotes the hydrogen release at moderate temperatures by tuning up the desorption thermodynamics [3]. It is likely that similar effects play a role also in the case of room temperature HCR processes in Li-cells. In this communication we discuss our recent results about the MgH2 conversion reaction in a lithium cell. Our study combines computational and experimental efforts in order to derive a comprehensive picture of the MgH2 HCRI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
