Fast kinetics of magnesium monochloride cations in interlayer-expanded titanium disulfide for magnesium rechargeable batteries

Abstract

Magnesium rechargeable batteries potentially offer high-energy density, safety, and low cost due to the ability to employ divalent, dendrite-free, and earth-abundant magnesium metal anode. Despite recent progress, further development remains stagnated mainly due to the sluggish scission of magnesium-chloride bond and slow diffusion of divalent magnesium cations in cathodes. Here we report a battery chemistry that utilizes magnesium monochloride cations in expanded titanium disulfide. Combined theoretical modeling, spectroscopic analysis, and electrochemical study reveal fast diffusion kinetics of magnesium monochloride cations without scission of magnesium-chloride bond. The battery demonstrates the reversible intercalation of 1 and 1.7 magnesium monochloride cations per titanium at 25 and 60 °C, respectively, corresponding to up to 400 mAh g−1 capacity based on the mass of titanium disulfide. The large capacity accompanies with excellent rate and cycling performances even at room temperature, opening up possibilities for a variety of effective intercalation hosts for multivalent-ion batteries.

In Operando Synchrotron Diffraction and in Operando X-ray Absorption Spectroscopy Investigations of Orthorhombic V2O5 Nanowires as Cathode Materials for Mg-Ion Batteries

“…The edge resonance (B and B' in Fig. 6) displays significant changes in both shape and intensity, which is associated with the energy absorption by core electrons 64,66 . For the discharging process, the shape changes from two broad peaks to a single broad peak (peak B in Fig.…”

Solvated Ion Intercalation in Graphite: Sodium and Beyond

“…Additionally, a Mg 2+ -DEGDME double-layer structure was proposed as the most stable configuration of fully discharged graphite according to DFT calculations. It is worth noting that the concept of improving Mg 2+ intercalation kinetics through solvent chelation has been expended to MgCl + , which lowers the polarization strength and activation barrier for Mg 2+ , leading to high power Mg ion batteries with TiS 2 (Yoo et al, 2017) or VOPO 4 (Zhou et al, 2018) electrodes.…”

Fast kinetics of multivalent intercalation chemistry enabled by solvated magnesium-ions into self-established metallic layered materials

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