TiF3 catalyzed MgH2 as a Li/Na ion battery anode

Abstract

MgH2 has been considered as a potential anode material for Li ion batteries due to its low cost and high theoretical capacity. However, it suffers from low electronic conductivity and slow kinetics for hydrogen sorption at room temperature that result in poor reversibility, cycling stability and rate capability for Li ion storage. This work presents a MgH2-TiF3@CNT based Li ion battery anode manufactured via a conventional slurry based method. Working with a liquid electrolyte at room temperature, it achieves an high capacity retention of 543 mAh g-1 in 70 cycles at 0.2 C and an improved rate capability, thanks to the improved hydrogen sorption kinetics with the presence of catalytic TiF3. Meanwhile, the first realization of Na ion uptake in MgH2 has been evidenced in experiments.

Nitrogen-Doped Carbon-Coated TiO2/TiF3 Heterostructure Nanoboxes with Enhanced Lithium and Sodium Storage Performance

“…21-1272) . Besides, some additional weak peaks of NC@TiO 2 /TiF 3 at 23.1 and 47.0° can be identified as TiF 3 . No TiOF 2 diffraction peaks were found, suggesting the full decomposition of TiOF 2 in pyrolysis.…”

“…31 Besides, some additional weak peaks of NC@ TiO 2 /TiF 3 at 23.1 and 47.0°can be identified as TiF 3 . 32 No TiOF 2 diffraction peaks were found, suggesting the full decomposition of TiOF 2 in pyrolysis. The relative content of TiF 3 in the TiO 2 /TiF 3 heterostructure can be evaluated by calculating the ratio of XRD peak areas (TiF 3 /TiO 2 + TiF 3 ).…”

Metallic and complex hydride-based electrochemical storage of energy

“…So far, only the Na case has been somewhat explored. Xu and Mulder reported the conversion between MgH 2 and Na at room temperature, but the reaction extent and the underlying mechanism could not be clearly established [62]. Also, the potential relevance of lithium-aluminum amide LiAl(NH 2 ) 4 as the Na anode has been proposed based on first-principles calculations [63].…”

Hydrides compounds for electrochemical applications

“…Beyond lithium, the conversion reaction of metallic hydrides with other alkaline or alkali-earths cannot be ruled out. Indeed, the case of sodium has been already foreseen with MgH2 [31] though the full mechanism of the reaction taking place at room temperature remains to be better understood. More recently, the properties of the complex lithium-aluminum amide LiAl(NH2)4 was theoretically reported as a possible Na anode material [32] opening the way to new routes for such conversion reactions.…”