Exploring the Peierls Distorted Vanadium Sulphide as A Rechargeable Mg Ion Cathod. pdf

Materials and Methods.VS4-reduced graphene oxide (rGO) powder was synthesized following the previous report of Rout. et. al. 16 The composites have 3 wt% rGO content. The particle sizes are in the range of 100-500 nm. 16 LiVS2 and K3VS4, which were used as model compounds for the S and V XANES measurements, were prepared by sealed tube method following the previous report by Britto et al. 17 K3VS4 was synthesized by grinding together stoichiometric quantities of K2S, V, and S and heating the mixture in a sealed tube at 650 C for 20 h. 24 Similarly, LiVS2 was prepared by heating the resultant mixture of Li2S, V, and S at 750 C for 20 h. 55 Another model compound MgS was synthesized by heating the MgSO4 (≥ 99.5%) powder in the stream of CS2-aerosolised Ar at 800 C for 4 hrs, the powder was cooled down, transferred to the glove box, grounded and heated again in the stream of CS2-aerosolised Ar. S powder was received from Sigma-Aldrich.Electrode preparation. VS4 was mixed homogenously with Ketjen Black and PVDF (weight ratio of 80: 10: 10) using N-Methyl-2-pyrrolidone (NMP, anhydrous, Sigma-Aldrich) and casted on copper foil in thickness of 150 µm. Film was dried at 60ᵒC under vacuum before punching out VS4 cathode of area 1.27 cm2 with loading~ 3 mg/cm2. Mg ribbon (Sigma Aldrich) was polished by blade to remove the MgO layer and cut into pieces of 8 mm X 3 mm X 0.2 mm to fit in 2032 type cells. A 0.25 (M) solution Mg (AlCl2EtBu) 2 in dry THF (supplied by Sigma Aldrich,≥ 99.0%, re distilled in lab and stored over molecular sieves showing final H2O content of 12 ppm by Karl Fisher titration) was …