A comparison of microstructure, mechanical properties and fracture behavior of Mg–9Gd–3Y–xZn–0.5Zr (x = 0, 0.2, 0.5, 1.0, and 1.5) (wt%) alloys under different thermal treatment conditions was investigated in this study. The results showed that the as-cast alloys were comprised of Mg matrix, eutectic compounds and cuboid-shaped phases. The eutectics were Mg24(Gd, Y)5 in the alloys of Zn content ≤0.2 wt%, while (Mg, Zn)3RE in the other three alloys. Fine lamellar long period stacking ordered structure formed inside of matrix of the as-cast Zn-containing alloys and its quantity increases with raising Zn content. Mg12(Gd, Y)Zn was observed at grain boundary of Mg matrix after solution treatment in the alloys of Zn content ≥0.5 wt%. Peak-aged Mg–9Gd–3Y–0.5Zn–0.5Zr alloy exhibited a desirable combination of strength and elongation with 244 MPa in yield strength, 371 MPa in ultimate tensile strength and 3.8% in EL. Meanwhile, the fracture behavior of the studied alloys was also investigated.

High-voltage (≥4.0 V) operation of supercapacitor devices was demonstrated using carbon nanotubes as active electrode materials combined with room temperature ionic liquids as electrolyte. Pouch cells were assembled with four different ionic liquids, 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM-BF4), diethyl-N-methyl-N-(2-methoxyethyl) ammonium bis(trifluoromethanesulfonyl)imide (DEME-TFSI), diethyl-N-methyl-N-(2-methoxyethyl)ammonium tetrafluoroborate (DEME-BF4), and 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr14-TFSI). Cyclic voltammetry showed the maximum operational voltage to be 4.5 V for DEME-TFSI and 4.7 V for DEME-BF4. Compared to electric double layer capacitor (EDLC) cells using propylene carbonate electrolyte at 2.7 V, capacitance increased by 20% using BMIM-BF4 at 4.0 V, DEME-TFSI at 4.5 V, DEME-BF4 at 4.7 V, and Pyr14-TFSI at 4.3 V, with tripling of energy density and comparable power density using Pyr14-TFSI-based EDLCs. Long-term cyclability using BMIM-BF4 ionic liquid electrolyte operating at 4.0 V showed retention of >80% of initial capacitance after 65,000 continuous cycles without doubling of initial cell equivalent series resistance.

The development of electrocatalysts with high activity and low cost has attracted growing attentions in recent years. Herein, we reported the Mn-doped CoP nanosheet arrays on flexible activated carbon cloth (Mn–CoP/CC) for the effective oxygen evolution reaction (OER) at low overpotential and high current density. Due to the novel 3D nanostructures of the carbon cloth and doping effect of the Mn element, the Mn doped CoP/CC electrode delivered the best overpotential of 317 mV for water splitting with the current density of 10 mA/cm2, a Tafel slope of ∼65.1 mV/dec, and excellent stability over 16 h in 1.0 mol/L KOH, which is superior or comparable to the most of the reported cobalt-based catalysts. Thus outstanding electrocatalytic performance originates from the Mn doping effect, which resulted in increased surface area and fast charge-transfer. It is believed that these findings would help us to develop high effective and stable electrocatalysts for water splitting.

Organic gels obtained by sol–gel polycondensation reaction followed by subcritical drying in ambient conditions are termed as xerogels which are pyrolyzed to yield carbon xerogels. Resorcinol formaldehyde (RF) derived carbon xerogels have received considerable attention due to their higher carbon yield and ease of tuning their microstructure and therefore physiochemical properties. Recent advances in the synthesis of carbon xerogels have allowed porous as well as non-porous but large external surface area morphologies. Further efforts have been made about increasing the surface area by activation or changing the microstructure by doping with foreign elements. These advances in the area of carbon xerogels synthesis led to their use as high performance anode materials for Li ion batteries recently. This review summarizes these recent studies on electrochemical performance of carbon xerogels to clearly demonstrate their potential as high capacity anode material for Li ion batteries. Notably, given the potential not only for Li ion batteries but also for latest sodium-ion batteries and super-capacitors, this review provides a much needed attention of scientific community to so far unnoticed carbon xerogel materials.