JPS61151971A - Battery apparatus - Google Patents

Abstract

PURPOSE:To improve a whole efficiency of a battery, according to a method wherein both electrodes are separated by a diaphragm selectively transmitting hydrogen ions mainly, and halogen and hydrogen additionally produced by electrode reaction are separated in gas and liquid, and are introduced in a reactor to be allowed to, and the generated hydrogen halide is returned into an original positive electrode active substance. CONSTITUTION:Hydrogen and halogen gas generated in the negative and positive electrodes 4 and 5 of a battery cell stack 3 are introduced into a reactor 10 from negative and positive electrodes active substance tanks 1 and 2 through lines 8a and 8b, and react here to generate hydrogen halide. The hydrogen halide is suitably returned to the tank 2 via a storage tank 11, and the required quantity of the hydrogen halide is supplied into an original positive electrode active substance. As described above, the additionally produced gas generated in negative and positive electrodes is separated in gas and liquid, and allowed to react in the reactor 10, and the additionally produced hydrogen halide is suitably returned into the battery, so that the quantity of the negative and positive electrodes active substances can be automatically rebalanced.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a battery device, and more particularly to a fuel cell such as an active material regeneration type such as a redox flow type secondary battery in which the battery active material of both electrodes is liquid. .

(Prior art) Some wet fuel cells, redox flow type secondary batteries, etc. have batteries in which the battery active materials at both electrodes are in a liquid state, and a combination of active materials (redox pair) is chromium divalent/trivalent - iron trivalent/bivalent pair,
There are equivalent combinations of titanium trivalent/tetravalent and iron trivalent/bivalent, but although these have the advantage in terms of control of chemical species, the activation force per cell is small, and Due to solubility constraints, the battery has a low energy density. In contrast, chromium-halogen batteries have a high electromotive force and can be expected to have a large output energy density. Since it is a fluid together with the substance, it has the advantage of being easy to handle. For this reason, batteries using chromium and halogen as negative and positive electrode active materials have been proposed (RF, 5avilland, D.A. Po1aski),
“Experimental Evaluation Op.
Prototype/Hybrid/Redox/Halogen/
Energy Storage System” (f!xper
mentalEvaluation of a Pr
ototype Hybrid Redox Hal.

gen Energy Storage System
), Sixteenth (16th), IECEC (IECEC), 819
385 (1781)).

(Problems to be Solved by the Invention) However, conventional battery systems have the following drawbacks.

(1) Suppresses the permeation of halogens (chlorine, bromine).

It is difficult to selectively transmit rotons with high conductivity, and there is a significant decrease in electrical efficiency and efficiency in repeated charging and discharging over a long period of time.

(2) Chromium, which is a negative electrode active material, generates hydrogen as a side reaction during charging. For this reason, the positive electrode side of the active material always tends to be overcharged, and if left untreated, the output of the battery will be significantly reduced.

(3) In order to increase the electrode reaction rate of chromium, which is the negative electrode active material, it is necessary to raise the operating temperature of the battery to about 40 to 60°C, but as the temperature rises, the retention power of /'%rogen in the liquid decreases. , storage of gas as a gas is required.

In addition, the movement (diffusion) of halogen gas into the negative electrode chamber through the diaphragm in the battery cell increases, and the Coulombic efficiency of the battery decreases significantly. Therefore, it is preferable to use a negative electrode that can perform an electrode reaction well even at room temperature.

(4) Completely suppress hydrogen gas generation on the negative electrode side,
Furthermore, it is generally difficult to recover all of the generated hydrogen gas. On the positive electrode active material side, halogen becomes excessive (overcharging on the positive electrode side) by the amount of hydrogen gas that has dissipated outside the battery system, causing problems in long-term charging and discharging.

An object of the present invention is to provide a battery device that improves the conventional chromium-halogen battery, eliminates overcharging on the positive electrode side due to side reactions, and improves the overall efficiency of the battery.

(Means for Solving the Problems) The present invention provides that the electrode reaction of the liquid negative electrode active material in the negative electrode is
A battery is constructed by the redox between valent chromium and trivalent chromium and the electrode reaction of the liquid positive electrode active material at the positive electrode between monovalent halogen and zero-valent halogen, and the electrode that carries out both electrode reactions is a solution-flow type. In a battery device that is a porous electrode, the two electrodes are separated by a diaphragm that selectively permeates mainly hydrogen ions, and the halogen and hydrogen produced as by-products in the electrode reaction are separated into gas and liquid and introduced into the reactor. The method is characterized in that the hydrogen halides produced are returned to the original positive electrode active material.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is an explanatory diagram showing a battery device of the present invention. The device q has a positive electrode 5, a negative electrode 4, and a distance l! A battery cell stack 3 having lI6, pumps 7a, 7b and lines 9a, 9b that supply a negative electrode active material and a positive electrode active material to the cell stack 3, respectively, and a tank 1 that stores the negative electrode active material and the positive electrode active material, respectively. and 2, lines 8a and 8b for extracting hydrogen generated on the negative electrode side of the battery cell stack 3 and halogen gas generated on the positive electrode side from storage tanks 1 and 2, respectively;
a reactor 10 for reacting hydrogen and halogen gas extracted from b, a container 11 for storing the hydrogen halide obtained in the reactor 10, and a container 11 for storing the hydrogen halide obtained in the reactor 10; A line 15a for supplying hydrogen, a line 15b for extracting excess halogen from the storage container 2 for the positive electrode active material, and a line 15b provided between the processing device 13 and the storage tanks 1 and 2 for the negative electrode and positive electrode active materials. and a monitor device 14 for measuring the amounts of these active materials.

Hydrogen and halogen gas generated at the negative electrode 4 and positive electrode 5 of the battery cell stack 3 are transferred to the negative electrode active material tank 1.
and is introduced into the reactor 10 from the positive electrode active material tank 2 through lines 8a and 8b, where it reacts to produce hydrogen halide.

This hydrogen halide is appropriately returned to the positive electrode active material tank 2 via the storage tank 11, and the required amount is supplied into the original positive electrode active material. In this way, by-product gases generated at the negative and positive electrodes are separated into gas and liquid, reacted in the reactor 10, and hydrogen halide, which is a reaction product, is appropriately returned to the battery system, thereby automatically adjusting the amount of positive and negative electrode active materials. It is possible to rebalance the charge and discharge depth of the positive and negative electrode active materials appropriately.

In the battery system of the present invention, the amount of halogen released to the outside of the battery system and the amount of hydrogen halide introduced into the battery system are determined by measuring the amounts of positive and negative electrode active materials using the monitor device 14, and determining the amount of the positive and negative electrode active materials, and these measured values are set to a predetermined value. Pulp (1 in Figure 1)
6a, 16b). In other words, in general, redox flow type secondary batteries that use divalent chromium oxide ions as negative electrode active materials produce hydrogen gas as a by-product as described above, so the current efficiency in the battery reaction is lower than that on the positive electrode side, and as a result, Since the positive electrode active material side becomes more overcharged than the negative electrode active material side, in the present invention, in order to solve this problem, halogen and hydrogen are reacted and a rebalance system is provided. Therefore, it is difficult to completely restore the balance to the original state.

For this reason, we are releasing halogens outside the battery system and introducing a new hydrogen halide.

The amount of these halogens released and the amount of hydrogen halide introduced are:
It is determined by the degree of imbalance between both active materials. For this purpose, the monitor device 14 (positive and negative electrode active material concentration analysis needles)
is provided to determine the amounts of positive and negative electrode active materials in both electrode solutions, and the hydrogen halide introduction valve 15a and release valve 15b are adjusted respectively so that these amounts are balanced.

The monitor device 14 includes coulometric analysis (Coulometry 1, especially the coulometric analysis cell of Patent Application No. 59-247643 filed by the present applicant filed on November 22, 1980), portammetry, potentiometry, and absorbance. An analyzer based on a method such as the above method is preferably used.

As the electrodes used in the battery cell stack 3, graphitic carbon electrodes with excellent conductivity such as graphitic carbon cloth, graphitic carbon nitrogen, etc. are preferably used. Graphitic carbon is powdered and subjected to X-ray diffraction analysis to show (112) in the diffraction peak.
) It is sufficient if the line is observable.

Furthermore, as the diaphragm 6 used in the electric cell stack 3, a cation exchange membrane in which sulfone groups are introduced into a polymer membrane (base membrane) is suitable, and the average macropore diameter of the membrane after the introduction of sulfone groups is 10 Å or less. is preferred. By using such an ion exchange membrane, the hydrogen ion selective permeability can be significantly improved, and the separation performance of the by-products can be improved.

Since there is a resolution limit for measuring the average macropore diameter of the diaphragm with a transmission electron microscope, we measured the water permeation rate when one side of the diaphragm was pressurized with water, and assumed that Poisier's law holds. It was calculated from the following formula.

Here, Am is the membrane area, Ap is the membrane pore area, and (Am/
The Ap value corresponds to the water content value of the membrane, which is approximately 0°3 to 0.5), where Q is the water permeation rate, δp is the pressure difference on both sides of the membrane, t is the membrane thickness, and μ is the viscosity coefficient.

The reactor 10 may be based on any of the following principles: a contact method using a catalyst, a combustion method, a hydrogen-halogen fuel cell method, or an electromagnetic wave irradiation method.

The chromium-halogen battery used in the present invention is practically available in two types: a chromium-chlorine battery and a chromium-bromine battery, but a chromium-bromine battery is particularly preferred from the viewpoint of maintainability, operability, safety, and the like. In addition, when using chlorine as the halogen, it is necessary to further provide heat exchange equipment for storing chlorine at a low temperature in the configuration shown in FIG.

According to the above embodiment, (1) since both active materials are liquid, the active material reaction section (battery cell stack 3) and storage section (tanks 1 and 2), etc. can be configured independently; Therefore, it has excellent emergency stop performance and load followability, and it is easy to select the charging and discharging time as a secondary battery. For example, the charging and discharging time rate can be adjusted simply by increasing or decreasing the amount of active material stored in the tank. Note that the output energy density of the battery of the present invention is comparable to that of conventional zinc-based batteries.

(2) By using a diaphragm with excellent hydrogen ion permeability as a diaphragm for the battery cell stack, the separation performance of hydrogen as a by-product can be improved, and the automatic rebalance function that is the main focus of the present invention can be effectively achieved. I can do it. (3) The concentration of battery material substances at both electrodes is monitored, and hydrogen halide is introduced into the battery system and excess halogen is released from the battery system based on the results. The concentration of the negative electrode active material is maintained at an appropriate level, and imbalances in the depth of charge, etc., do not occur.

Hereinafter, specific examples of the present invention will be described.

Example 1 As a test battery cell stack, the apparent electrode area was 10
We created a small cell charging/discharging test system with positive and negative electrodes with a mouth height of 1 cm @ (1 crane in thickness), with both electrodes separated by a cation exchange membrane, and by variously changing the carbon electrode and diaphragm, we A constant current charge/discharge test was conducted at a current density of 40 mA/-. As active materials, 4N hydrobromic acidic 2 mol/l chromium chloride (bromine-chromium battery) and 4N hydrochloric acid acidic 2 mol/l chromium chloride (chlorine-chromium battery) were used.

As the carbon electrodes, carbonaceous <x is diffraction pattern with no (112) diffraction peak observed) and graphite (with a (112) diffraction peak visible) carbon knit were used. In addition, as a diaphragm, the conventional general cation exchange membrane M-1 (polystyrene sulfonic acid-based cation exchange membrane reinforced with polyvinyl chloride, average macropore diameter determined by measuring the amount of permeated water is 20 people), the same M-1 (
Same material as M-2 with an average macropore diameter of 9 Å or less), and perfluorosulfonic acid cation exchange 111M-
3 (average macropore system of about 25 to 30 Å or less) was used.

The results of these tests are shown in Table 1.

Table 1 below shows the results in Table 1, which show that the M-2 battery cell structure using graphitic carbon nift is particularly excellent.

Example 2 As battery cell stack components, the same graphitic carbon knit electrode and diaphragm as those used in Example 1 were used. A battery system having the configuration shown in FIG. 1 was manufactured using the following. As the active material, a 4N hydrogen bromide pressure 2 mol/i chromium chloride aqueous solution was used. The reactor 10 is a combustion type reactor, the monitor device 14 is a two-stage potentiometer, and the potential of the negative electrode active material is measured with reference to a silver-silver chloride electrode. The material potential was measured to understand the charging and discharging states of both active materials. The excess halogen treatment device 13 used was one based on an alkali absorption method.

Repeated charge/discharge cycle test (1) when all devices such as reactor 10 and excess halogen treatment device 13 are operated well
, a cycle test (2) in which the functions of the reactor 10, hydrogen halide storage tank 11, and excess halogen treatment device 13 were stopped, and a cycle test (3) in which only the hydrogen halide introduction device 12 and excess halogen treatment device 13 were stopped. ) was carried out.

The number of cycles until the output capacity decreased to 80% or less at room temperature and 40 mA/constant current charging/discharging was as shown in Table 2.

Table 2 (Effects of the Invention) The battery device of the present invention has the following excellent features.

(1) A secondary battery (active material regeneration type fuel cell) that has high output and can be easily enlarged can be obtained. (2) Maintenance is extremely easy, and unmanned automated operation can be easily achieved. (3) Since there is no solid phase reaction in the battery reaction, the battery has a long life and fewer causes of accidents. (4) Load followability can be easily achieved. (5) Since no expensive materials are used, it can be manufactured at low cost.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a battery device showing one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Negative electrode active material storage tank, 2... Positive electrode active material storage tank, 3... Battery cell stack, 4... Negative electrode,
5... Positive electrode, 6... Diaphragm, 10... Reactor, 11
... No. 10 Hydrogenated storage tank, 12... Hydrogen halide introduction device, 13... Excess halogen treatment device, 1
4...Battery active material concentration monitoring device. Agent Patent attorney Takeshi Kawakita Long procedural amendment writing method) % formula % 1. Indication of the case 1981 Patent Application No. 281657 2) Title of the invention Battery device 3, person making the amendment Relationship with the case Patent applicant Address: 5-6-4 Tsukiji, Chuo-ku, Tokyo Name (5)
90) Mitsui Engineering & Shipbuilding Co., Ltd. Representative Kazuo Maeda 4, Agent 103 Address 11-8 Nihonbashi Kayabacho, Chuo-ku, Tokyo (
Benimoe Building) Telephone 03 (639) 5592 Name (7658) Patent Attorney Takeshi Kawakita 5. Date of amendment order: April 10, 1985 (shipping date: April 30, 1985) 6. Subject: Full text of the specification 7. Contents of amendment: As per the engraving and attached sheet of the specification originally attached to the application (no change in content).

Claims (5)

[Claims] (1) The electrode reaction of the liquid negative electrode active material at the negative electrode is the oxidation-reduction between divalent chromium and trivalent chromium, and the electrode reaction of the liquid positive electrode active material at the positive electrode is the oxidation-reduction between monovalent halogen and zero-valent halogen. In a battery device in which the electrodes that carry out the two-electrode reaction are solution-flowing porous electrodes, the two electrodes are separated by a diaphragm that selectively permeates mainly hydrogen ions, and the by-products of the electrode reaction are separated. 1. A battery device characterized in that halogen and hydrogen are separated into gas and liquid, introduced into a reactor to react, and the generated hydrogen halide is returned to the original positive electrode active material. (2) A battery device according to claim 1, characterized by having means for timely introducing hydrogen halide and means for timely discharging excess halogen outside the battery system. (3) In claim 2, the amount of positive and negative electrode active materials is measured, and the amount of hydrogen halide introduced into the battery system and the amount of halogen removed from the battery system are determined so as to maintain the balance between them. 1. A battery device comprising a control device that determines the amount of emitted. (4) A battery device according to claim 1, characterized in that a graphite carbonaceous material is used as the solution flow type porous electrode. (5) The battery device according to claim 1, wherein the diaphragm separating the two electrodes is a cation exchange membrane having a sulfone group, and the average macropore diameter of the membrane is 100 Å or less. .