RESUMO
The low specific capacity and Mg non-affinity of graphite limit the energy density of ion rechargeable batteries. Here, we first identify that the monolayer C12-3-3 in sp2-sp3 carbon hybridization with high Li/Mg affinity is an appropriate anode material for Li-ion batteries and Mg-ion batteries via the first-principles simulations. The monolayer C12-3-3 can achieve high specific capacities of 1181 mAh/g for Li and 739 mAh/g for Mg, higher than those of most previous anodes. The Li storage reaction is an "adsorption-conversion-intercalation mechanism", while the Mg storage reaction is an "adsorption mechanism". The 2D carbon material of C12-3-3 displays fast diffusion kinetics with low diffusion barriers of 0.41 eV for Li and 0.21 eV for Mg. As a new carbon-based anode material, the monolayer C12-3-3 will promote the practical application of batteries with high-capacity and high-rate performance.
RESUMO
Although magnesium rechargeable batteries (MRBs) have gained considerable attention, research relating to MRBs is still in its infancy. One issue is that magnesium ions are difficult to reversibly (de)intercalate in most electrode materials. Among various available cathodes, VO2(B) is a promising layered cathode material for use in MRBs. Totally different from monolayer VO2, the magnesiation mechanism in monoclinic bulk VO2(B) has not been clearly clarified to this day. For the first time, we systematically investigated the influence of magnetism and van der Waals (vdW) forces on the electronic structure and diffusion kinetics of magnesium in bulk VO2(B) using a series of DFT+U calculations. The Mg diffusivity can reach a high value of 1.62 × 10-7 cm2 s-1 at 300 K, which is comparable to Li+. These results demonstrate that VO2(B) is a potential host material with high mobility and fast kinetics.
RESUMO
In the crystal structure of the title compound, (C(12)H(12)N(4)O(2))(2)[Mo(8)O(26)], the amino and pyridinium groups of the N(1),N(2)-di(pyridinium-4-yl)oxalamide cations are hydrogen bonded to the O atoms of the centrosymmetric isopolyoxometalate ß-[Mo(8)O(26)](4-) anions, forming a three-dimensional supra-molecular architecture.
