Anode Material For Mg-ion Batteries Research Articles

In situ synthesis of bismuth (Bi)/reduced graphene oxide (RGO) nanocomposites as high-capacity anode materials for a Mg-ion battery

Herein, in situ reduction of bismuth and graphene oxide was performed by a solvothermal method under a N2 atmosphere, and the resulting Bi/RGO nanocomposites were used as an anode material for Mg-ion batteries.

Density functional theory calculations for evaluation of phosphorene as a potential anode material for magnesium batteries.

We have systematically investigated black phosphorus and its derivative – a novel 2D nanomaterial, phosphorene – as an anode material for magnesium-ion batteries. We first performed Density Functional Theory (DFT) simulations to calculate the Mg adsorption energy, specific capacity, and diffusion barriers on monolayer phosphorene. Using these results, we evaluated the main trends in binding energy and voltage as a function of Mg concentration. Our studies revealed the following findings: (1) Mg bonds strongly with the phosphorus atoms and exists in the cationic state; (2) Mg diffusion on phosphorene is fast and anisotropic with an energy barrier of only 0.09 eV along the zigzag direction; (3) the theoretical specific capacity is 865 mA h g−1 with an average voltage of 0.833 V (vs. Mg/Mg2+), ideal for use as an anode. Given these results, we conclude that phosphorene is a very promising anode material for Mg-ion batteries. We then expand our simulations to the case of bulk black phosphorus, where we again find favorable binding energies. We also find that bulk black phosphorous must overcome a structural stress of 0.062 eV per atom due to a volumetric expansion of 33% during magnesiation. We found that the decrease in particle size is good to increase its specific capacity.

Ultrathin TiO2-B nanowires as an anode material for Mg-ion batteries based on a surface Mg storage mechanism.

Ultrathin TiO2-B nanowires with a naked (-110) surface were prepared by a hydrothermal process and used as the anode material for Mg-ion batteries. The material delivered a reversible Mg2+ ion capacity of 110 mA h g-1 at the 0.1C rate. Excellent cycling stability was achieved with a small capacity-fading rate of 0.08% per cycle. In addition, a discharge capacity of 34 mA h g-1 was obtained at the 50C rate, demonstrating the material's excellent high rate capability. First-principles calculations showed that Mg2+ ions hardly penetrated into the TiO2-B lattice because of a very large Mg2+ ion diffusion barrier of 0.63 eV. Instead, the Mg2+ ions were stored at the 4-coordinated vacancies of TiO2-B nanowire (-110) surfaces. The adsorbed Mg2+ ions were bonded with unpaired surface oxygen atoms. Meanwhile, a small amount of electrons were transferred from the O-2p state to the Ti-3d state.

Electrochemical Characterization and Interfacial Chemistry of Tin-Based Anode Materials for Mg-Ion Batteries

Magnesium-ion batteries have received a particular attention as one of the beyond-lithium ion batteries for next-generation energy storage system applications. Magnesium is earth abundant and low cost compared to lithium, and environment-friendly, and provides higher theoretical volumetric capacity (3833 mAhcm-3) than lithium.1 The use of magnesium metal anode is often limited due to the formation of surface blocking layer in conventional electrolyte such as magnesium salts (TFSI-, ClO4 -, BH4 -) in ether-based solvents. To overcome these problems, recently insertion-type materials such as Sn, Sb, Pb and Bi, which is based on the alloy reaction with magnesium, have been proposed as a new class of anode materials for magnesium-ion batteries.2,3 However, studies on the materials’ intrinsic electrochemical characteristics and the interfacial chemistry between alloy anode and electrolyte are yet to be reported. In the present study, we have investigated on the electrochemical and interfacial reaction behavior of tin-based anode materials in magnesium cells. Changes with cycling in their structure, surface property and particle morphology would be discussed in the meeting. Acknowledgements This work was supported by National Research Foundation of Korea (2015062107).

Monolayer black phosphorus as potential anode materials for Mg-ion batteries

Adsorption and diffusion of Mg atom on the monolayer black phosphorus (P) and its structural stability with the increasing Mg concentrations were investigated using density functional theory. The adsorption energy was −1.09 eV for the Mg adsorbed on the monolayer black P. The Mg ions showed an anisotropic diffusion behavior on the monolayer black P with diffusion barriers of 0.08 and 0.57 eV along the zigzag and armchair directions, respectively. The monolayer of black P can keep the lattice structure stable forming as the Mg0.5P. These results proved that the monolayer black P can be used as a potential anode for Mg-ion batteries.