An electrolyte composition and a battery is provided. The electrolyte composition includes graphene. The electrolyte composition of the present invention is suitable for a battery and can improve the life cycle of the battery. The application process of the electrolyte composition of the present invention is simple and more cost-efficient as compared to conventional techniques which add carbon material(s) to a battery. The present invention is effective in improving battery performance.

An electrolyte for a redox flow battery has a total concentration of arsenic ions and antimony ions of 15 mass ppm or less. In an example of the electrolyte for a redox flow battery, preferably, the concentration of the arsenic ions is 10 mass ppm or less. In another example of the electrolyte for a redox flow battery, preferably, the concentration of the antimony ions is 10 mass ppm or less.

A bipolar battery (1) comprising a stack of multiple bipolar plates (9) sandwiched between two monopolar plates (6, 8) is disclosed. The bipolar plates (9) each comprise a conductive polymer core (22) and an integrally formed non-conductive polymer surround (4), a layer of cathode material (16) on a first side of the bipolar plate (9), and a layer of anode material (28) on a second, opposite side of the bipolar plate (9). The integrally formed non-conductive polymer surround (4) extends from the conductive polymer core (22) further on one side than the other, such that on one side a first recess (19) is defined for accommodating electrolyte material of the battery (1). The layers of anode material (28) and cathode material (16) are contained within a casing formed at least in part by the integrally formed non-conductive polymer surrounds (4) of all of the bipolar plates (9).

Redox flow battery systems having a supporting solution that contains Cl.sup.− ions can exhibit improved performance and characteristics. Furthermore, a supporting solution having mixed SO.sub.4.sup.2− and Cl.sup.− ions can provide increased energy density and improved stability and solubility of one or more of the ionic species in the catholyte and/or anolyte. According to one example, a vanadium-based redox flow battery system is characterized by an anolyte having V.sup.2+ and V.sup.3+ in a supporting solution and a catholyte having V.sup.4+ and V.sup.5+ in a supporting solution. The supporting solution can contain Cl.sup.− ions or a mixture of SO.sub.4.sup.2− and Cl.sup.− ions.

The invention provides sulfuric acid efficiency electrolytes including a surfactant, preferably an amphoteric or a non-ionic surfactant, and/or phosphoric acid, the sulfuric acid efficiency electrolyte preferably further including at least one of a chelating agent and a crystal growth regulator, and optionally, a filler. The invention further provides sulfuric acid electrolytes including a filler, at least one chelating agent, and at least one water-soluble sulfate salt, wherein the chelating agent comprises an alkali metallated chelating agent and the water-soluble sulfate salt comprises the corresponding cation to the cation present in the alkali metallated chelating agent. The invention further provides lead sulfuric acid batteries including a positive electrode, negative electrode, and the efficiency electrolyte of the invention disposed therebetween.

The present disclosure relate to a method for preparing a cathode electrolyte for redox flow batteries including the steps of: forming a first cathode electrolyte by reducing vanadium pentoxide (V.sub.2O.sub.5) in an acidic solution in the presence of a specific reducing compound; forming a second cathode electrolyte by reducing vanadium pentoxide (V.sub.2O.sub.5) in an acidic solution in the presence of a linear or branched aliphatic alcohol having 2 to 10 carbon atoms; and mixing the first cathode electrolyte and the second cathode electrolyte, and to a redox flow battery including the cathode electrolyte obtained by the preparation method.

A lead-acid battery includes an electrode plate assembly, a battery case, a positive electrode strap, a negative electrode strap, a positive electrode post, a negative electrode post, a cover, and an electrolyte solution. A negative electrode bushing provided in the cover and the negative electrode post together constitute a negative electrode terminal. A maximum value of a gap between an outer circumferential surface of the negative electrode post and an inner circumferential surface of the negative electrode bushing in the negative electrode terminal is 0.5 mm or more and 2.5 mm or less. A rib is provided in a lower part of the negative electrode bushing, and a minimum value of a protrusion height of the rib is 1.5 mm or more and 4.0 mm or less. A distance between a surface of the electrolyte solution and a lowermost portion of the negative electrode bushing is 15 mm or less.

A battery maintenance system includes an enclosure including a plurality of walls. A plurality of battery cells are located in the enclosure and surrounded by electrolyte. An electrolyte agitator such as a piezoelectric device is attached to at least one of the walls of the enclosure and is configured to selectively agitate the electrolyte.

A lead-acid battery includes a positive electrode plate, a negative electrode plate, and an electrolyte solution. The negative electrode plate includes a negative electrode material. The negative electrode material contains a polymer compound. The polymer compound has a peak in a range of 3.2 ppm or more and 3.8 ppm or less in a chemical shift of .sup.1H-NMR spectrum, or the negative electrode material contains a polymer compound having a repeating structure of oxy C.sub.2-4 alkylene units.

An electrolyte system for improving electrolyte performance characteristics is provided. The electrolyte system includes an electrolyte, and a synthetic proton-conductive polymer additive. A cell comprising said electrolyte system and a method of making the same is also disclosed herein. The synthetic proton-conductive polymer additive may be used in conjunction with a bipolar overvoltage battery pulser to improve overall battery performance.