Sumitomo Electric Industries, Limited

The Kansai Electric Power Co., Inc.

Other

Nippon Chemical Industrial Co., Ltd.

Nobuyuki Tokuda

Toshio Shigematsu

Hiroyuki Nakaishi

Michiru Kubata

Takefumi Ito

Yasuyuki Tanaka

Takashi Kanno

Takahiro Kumamoto

Muneo Mita

Hiroshige Deguchi

Seiji Ogino

Ken Horikawa

Shinichi Miyake

Yasumitsu Tsutsui

Toshihisa Adachi

Toshihiko Takiguchi

Masayuki Furuya

Takefumi Itou

Takahiro c/o Osaka Works Of Sumitomo Kumamoto

Takashi c/o Osaka Works Of Sumitomo Kanno

Hiroyuki c/o Osaka Works Of Sumitomo Nakaishi

Seiji c/o Osaka Works Of Sumitomo Elec Ogino

Takefumi c/o Osaka Works Of Sumitomo Ito

Toshio c/o Osaka Works Of Sumitomo Shigematsu

This invention provides a cell stack for a redox flow battery that can provide battery efficiencies with high reliability over a long term, without any adhesive bonding between a bipolar plate and electrodes. In the cell stackfor the redox flow battery of a cell frame, electrodesand a membranebeing stacked in layers, the cell framecomprises a frameA and a bipolar platearranged inside of the frameA, and the electrodesare put into close contact with the bipolar plateby a clamping force, without being adhesively bonded to the bipolar plate. It is preferable that when the electrodesare compressed to a thickness corresponding to a level difference between the frameA and the bipolar plate, repulsive force of the electrodes is in the range of more than 15 kPa to less than 150 kPa (more than 0.153 kgf/cmto less than 1.53 kgf/cm).

Cell stack for redox flow battery

The invention provides an operating method of a redox flow battery capable of grasping a charging state of the battery more reliably to stabilize an output capacity of the battery. The method is for operating the redox flow battery comprising a cell stackcomprising a plurality of cells. A selected cell(s) in the cell stack, to and from which positive electrode electrolyte and negative electrode electrolyte are supplied and discharged and which is/are not normally connected to a DC/AC converter, is/are in the form of an auxiliary cellused for measuring a charging rate of the electrolyte. Also, a stop of charge of a main celland a stop of discharge of the main cellare controlled with reference to a circuit voltage obtained from the auxiliary cell. Since the auxiliary cellis integrally incorporated in the cell stack, the charging state of the battery can be grasped reliably without stopping the charge/discharge operation of the main cell. Also, since the stop of charge of the main celland the stop of discharge of the same are controlled with reference to the measured circuit voltage, the output capacity can be stabilized.

Method for operating redox flow battery and redox flow battery cell stack

The present invention provides a method of designing a redox flow battery system that can prevent system efficiency loss caused by weak generation power or load power at the time of electric charge or discharge, without using any lead storage battery, and can also provide further improved system efficiency. In the present invention, generating equipment that varies irregularly in output of power generation is provided with the redox flow battery to smooth the output of power generation. An average value of output distribution of the battery with respect to the smoothed output of power generation and standard deviation are determined. Then, at least either of a specified output of the battery and a specified output of the converter for converting the battery output is determined based on the standard deviation.

Method for designing redox flow battery system

This invention provides a cell frame for a redox flow battery that prevents leakage of electrolyte out of the cell frame and also provides a good workability in assembling the redox flow battery. Also, this invention provides a redox flow battery using the cell frame. In the cell framefor the redox flow batterycomprising a bipolar plateand a framefitted around a periphery of the bipolar plate, the framehas, on each side thereof, an inner seal and an outer seal to press-contact with a membrane and also seal electrolyte. The framehas, on each side thereof, an inner seal grooveand an outer seal groovefor placing therein the inner seal and the outer seal, respectively, to prevent the electrolyte from leaking out, and O-rings are placed in the respective seal grooves.

Cell stack for redox flow battery, and redox flow battery

The present invention provides electrolyte that can suppress reduction of battery efficiencies and capacities with increased cycles of charge/discharge of the battery, a method for producing the same, and a redox flow battery using the same electrolyte. The redox flow battery uses the electrolyte having a NHcontent of not more than 20 ppm and a relation of Si concentration (ppm)&#xd7;electrolyte quantity (m)/electrode area (m) of less than 5 ppm&#xb7;m/m. By limiting a quantity of contaminants in the electrolyte, a clogging of carbon electrodes to cause reduction of the battery performances with increased charge/discharge operations can be suppressed.

Electrolyte for redox flow battery, and redox flow battery

A simplified, pressure-variation preventing tank structure capable of preventing pressure variations in a gas phase portion resulting from temperature variations, without bringing stored liquid into contact with air. This pressure-variation preventing structure includes a breather bag arranged in a gas phase portion of a tank and inflating/deflating in communication with outside air, and a manhole to which the breather bag is attached to suspend in a gas phase portion, including a communication hole for the breather bag to communicate with outside air. The breather bag has air-blocking, acid-resistant and expandable characteristics.

Pressure fluctuation prevention tank structure, electrolyte circulation type secondary battery, and redox flow type secondary battery

The invention provides a secondary battery system that allows a high overload operation regardless of discharging condition during a steady operation, and an operating method thereof. The secondary battery system comprises first tanksfor reserving electrolytes required for a steady operation, and second tanksfor reserving electrolytes required for an emergency operation. Valvesare opened and closed for allowing selective switching between the electrolytes in the first tanksand the electrolytes in the second tanksto circulate the selected electrolytes through a cell stack. The electrolytes reserved in the second tanksare electrolytes having a proportion of a quantity of active material produced in a charging reaction to a total quantity of active material of not less than 50%.

Method of operating a secondary battery system having first and second tanks for reserving electrolytes

An operating method of a redox flow battery system that can provide a stabilized output to a system from a redox flow battery system annexed to a wind power generator, to produce an improved battery efficiency. The redox flow battery system comprises the wind power generatora redox flow batteryannexed to the wind power generator, and an AC/DC converterconnected to the redox flow battery. In the operating method, an output of the wind power generator within a certain period of time in the past is subjected to a first averaging process; a present output value of the wind power generator is subtracted from the resulting value of the first averaging process, from which an input/output command value to the AC/DC converteris determined; the input/output command value is subjected to a variation computing process to find variation without any consideration of a sign of the input/output command value; the resulting value obtained by the variation computing process is further subjected to a second averaging process, and an output command value for a pump P to circulate electrolytic solution of the redox flow battery is determined based on the result of the second averaging process.

Method for operating redox flow battery system

A modified vanadium compound characterized in that vanadium sulfate (III), or a mixed vanadium compound of vanadium sulfate (III) and vanadyl sulfate (IV) contains excessive sulfuric acid other than sulfate group composing the vanadium sulfate (III) or the vanadyl sulfate (IV), and when the modified vanadium compound is used, a redox flow battery electrolyte can be prepared easily.

Modified vanadium compound, producing method thereof, redox flow battery electrolyte composite and redox flow battery electrolyte producing method

An electrolyte tank which allows effective use of existing space of various shapes is provided. An electrolyte tank is formed by laminating one or more layers of coated fabric provided by coating a woven fabric of organic fiber with rubber or plastic and processing the laminated coated fabric to a bag-shape.

Electrolyte tank and manufacturing method thereof

The present invention provides method of producing a trivalent and tetravalent mixed vanadium compound having excellent solubility with sulfuric acid directly from a tetravalent or pentavalent vanadium compound by using a reducing agent,and a method of producing a vanadium electrolyte. For example, a vanadium compound mainly containing a pentavalent vanadium compound; sulfur and concentrated sulfuric acid in molar ratios with respect to (one mol of vanadium atom in the pentavalent vanadium compound) 0.35 to 0.4:1.2 to 1.9 are kneaded into paste form, and the paste-form mixture is calcined at a temperature of not less than 150&deg; C. to less than 440&deg; C. so that a trivalent and tetravalent mixed vanadium compound is obtained, and a redox flow battery-use vanadium electrolyte is obtained by dissolving the trivalent and tetravalent mixed vanadium compound in a sulfuric acid solution.

Trivalent and tetravalent mixed vanadium compound producing method and vanadium electrolyte producing method

A battery diaphragm having superior chemical resistance, low resistance, superior ion selective permeability and high mechanical strength is provided. The battery diaphragm is formed of a composite film including a complex of a porous base substrate (A) with a crosslinked polymer (B ) containing repeated units of a vinyl heterocyclic compound having at least two hydrophilic groups. Alternatively, the battery diaphragm is formed of a composite film including a complex of a porous base substrate (A) with a crosslinked polymer (B2) containing repeated units of a vinyl compound each having a functional group, and thereafter decomposing part of the functional groups. Alternatively, the battery diaphragm is formed of a composite film including a complex of a porous base substrate (A) with a crosslinked polymer (B3) containing repeated units of a vinyl compound each having a functional group, wherein the complex of the porous base substrate (A) with the crosslinked polymer is prepared by impregnating a porous structure of the porous base substrate (A) with a monomer mixture containing a crosslinking momomer and the vinyl compound having functional groups, and thereafter causing photopolymerization to generate the crosslinked polymer (B3) in the porous structure.

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Osaka, Japan

Nobuyuki Tokuda