A zinc ion battery includes a cathode; an anode; a separator; and an electrolyte sandwiched between the cathode and the anode. The electrolyte includes a mixture of zinc perchlorate and sodium perchlorate, and a ratio of the sodium perchlorate to zinc perchlorate is at least 30.

A zinc ion battery includes a cathode; an anode; a separator; and an electrolyte sandwiched between the cathode and the anode. The electrolyte includes a mixture of zinc perchlorate and sodium perchlorate, and a ratio of the sodium perchlorate to zinc perchlorate is at least 30.

An object is to provide an electrode active material that can provide an alkali metal battery having a longer charge/discharge life and a higher capacity. The problem is solved by means of an electrode active material for an alkali metal battery, represented by formula: A.sub.a1MS.sub.a2X.sub.a3 wherein A is selected from Li and Na; M is selected from V, Nb, Ta, Ti, Zr, Hf, Cr, Mo, and W which are group 4 to 6 elements; X is selected from F, Cl, Br, I, CO.sub.3, SO.sub.4, NO.sub.3, BH.sub.4, BF.sub.4, PF.sub.6, ClO.sub.4, CF.sub.3SO.sub.3, (CF.sub.3SO.sub.2).sub.2N, (C.sub.2F.sub.5SO.sub.2).sub.2N, (FSO.sub.2).sub.2N, and [B(C.sub.2O.sub.4).sub.2]; a1 is 1 to 9; a2 is 2 to 6; when a3 is 3 and a3 is 0, a2 is not 4; and when M does not include V, a3>0.

There is provided a secondary battery including a cathode, an anode including an anode active material layer and a coating film, and an electrolytic solution. The anode active material layer includes a titanium-containing compound, and a surface of the anode active material layer is coated with the coating film. The electrolytic solution includes one or more of unsaturated cyclic carbonate esters. Porosity of a portion of the anode active material layer measured with use of a mercury intrusion technique is within a range from 30% to 50% both inclusive. The portion of the anode active material layer is cut together with a portion of the coating film from a surface of the coating film to a depth of 10 μm.

A method for determining an average oxidation state (AOS) of a redox flow battery system includes measuring a charge capacity for a low potential charging period starting from a discharged state of the redox flow battery system to a turning point of a charge voltage; and determining the AOS using the measured charge capacity and volumes of anolyte and catholyte of the redox flow battery system. Other methods can be used to determine the AOS for a redox flow battery system or use discharge voltage instead of charging voltage.

A method for determining an average oxidation state (AOS) of a redox flow battery system includes measuring a charge capacity for a low potential charging period starting from a discharged state of the redox flow battery system to a turning point of a charge voltage; and determining the AOS using the measured charge capacity and volumes of anolyte and catholyte of the redox flow battery system. Other methods can be used to determine the AOS for a redox flow battery system or use discharge voltage instead of charging voltage.

Disclosed herein are embodiments of low temperature co-fireable dielectric materials which can be used in conjunction with high dielectric materials to form composite structures, in particular for isolators and circulators for radiofrequency components. Embodiments of the low temperature co-fireable dielectric materials can be scheelite or garnet structures, for example, bismuth vanadate. Adhesives and/or glue is not necessary for the formation of the isolators and circulators.

The invention provides for the orchestrated treatment of disparate fractions of a shale deposit to recover vanadium values, with distinct steps of beneficiation that together provide a combined vanadium-enriched concentrate amenable to subsequent combined steps of hydrometallurgical vanadium extraction.

A CoVO.sub.x composite electrode and method of making is described. The composite electrode comprises a substrate with an average 0.5-5 μm thick layer of CoVO.sub.x having pores with average diameters of 2-200 nm. The method of making the composite electrode involves contacting the substrate with an aerosol comprising a solvent, a cobalt complex, and a vanadium complex. The CoVO.sub.x composite electrode is capable of being used in an electrochemical cell for water oxidation.

Preparation, characterization, and an electrochemical study of Mg.sub.0.1V.sub.2O.sub.5 prepared by a novel sol-gel method with no high-temperature post-processing are disclosed. Cyclic voltammetry showed the material to be quasi-reversible, with improved kinetics in an acetonitrile-, relative to a carbonate-, based electrolyte. Galvanostatic test data under a C/10 discharge showed a delivered capacity >250 mAh/g over several cycles. Based on these results, a magnesium anode battery, as disclosed, would yield an average operating voltage ˜3.2 Volts with an energy density ˜800 mWh/g for the cathode material, making the newly synthesized material a viable cathode material for secondary magnesium batteries.