WO2011137895A2

WO2011137895A2 - Redox battery system

Info

Publication number: WO2011137895A2
Application number: PCT/DE2011/001026
Authority: WO
Inventors: Werner Henze
Original assignee: Bani, Ibrahim; Gaub, Lothar
Priority date: 2010-05-04
Filing date: 2011-05-04
Publication date: 2011-11-10
Also published as: DE112011101796A5; WO2011137895A3

Abstract

The invention relates to a redox battery system. The redox battery system comprises a redox battery having a pair of chamber arrangements, which contain aqueous solutions of salts in different oxidation states as electrolytes, a pair of electrode arrangements for discharging electrical energy during the discharging process and supplying electrical energy during the charging process, said electrode arrangements being associated with the pair of chamber arrangements, and an intermediate electrode arrangement between the two chamber arrangements of the pair. The redox battery system also comprises external pairs of electrolyte tanks having electrolytes, pairs of electrolyte lines between the chamber arrangements and electrolyte tanks, and a controllable pair of pumps and valves. The chamber arrangements of the pair have the same number of sub-chamber pairs. A second sub-chamber adjoins the first sub-chamber, and further successive sub-chambers are adjoining in the same way. During a discharging phase, the ratio of the charged salts to the uncharged salts of the electrolyte is greatest in the first sub-chamber and is less than in the preceding sub-chambers in each of the successive sub-chambers. The volumes of the sub-chambers and the reaction surfaces of the electrode arrangements and intermediate electrode arrangement increase in an opposite manner. There is a controlled flow of the electrolytes between the electrolyte tanks and the chamber arrangements. The electrode arrangements and the intermediate electrode arrangement each have a separate electrode pair and a separate intermediate electrode per sub-chamber pair. The electrical potentials of the sub-chamber pairs at the electrode pairs are connected in series in a discharging phase and in parallel in a charging phase.

Description

Redoxakkumulatoranlage

The invention relates to a redox accumulator system according to the preamble of claim 1.

From DE 10200600720β A1 a redox accumulator is known which contains inexpensive electrolytes, has a high terminal voltage and whose self-discharge is negligible. It comprises two chambers which contain electrolytes, namely aqueous solutions of salts in different oxidation states, two electrodes each assigned to one of the chambers for discharging electrical energy during the discharging process and supplying electrical energy during the charging process and a common intermediate electrode between the chambers. The electrodes behave with respect to the electrolyte within and allow only electrochemical reactions.

The capacity of the reservoirs present in the redox accumulator plant depends on the amount of "discharged" and "charged" salt fractions.

The invention is based on the object to provide a Redoxakkumulatoranlage whose available Entladeleistung varies as little as possible over a large period as possible and allows a variety of charging the memory of the Redoxakkumulatoranlage.

These objects are achieved by according to the preamble of claim 1 by the features of this claim. Further developments and advantageous embodiments will become apparent from the Untersprüchen.

The solution according to the invention is based on the following considerations, that the redox accumulator system is able to optimally use feedable and traceable energy so that, overall, hardly any energy losses occur and that previous climate-damaging effects cease. A separation of the charged in the chamber assemblies salt components to the discharged salt fractions is not physically possible directly. However, the ratio of the salt components determines the discharge and charging capacity of the redox accumulator. By fractional discharges in several separate Teilkammem and summation of the discharge of the individual Teilkammem different ratios of the charged salt components are used to the discharged salt fractions optimally for the total available discharge power.

The Teilkammem have overflows to adjacent sub-chambers. As the ratio of the charged salt fractions to the discharged salt fractions decreases from sub-chamber to sub-chamber, the volume of the sub-combs themselves, and thus also the total salt content therein, increases. The same applies to the surface of the electrodes. By this measure, the decreasing in itself with the reduction of the ratios of the charged salt fractions to the discharged salt fractions discharge capacity from part to chamber chamber is compensated and all Teilkammem can provide the same discharge capacity. This is a prerequisite for a summation of the discharge power by a series connection of the electrodes of the Teilkammem. By a continuous internal supply of electrolyte with charged salt fractions depending on the actually requested unloading power results in a steady state with respect to the ratios of the charged salt fractions to the discharged salt fractions in the respective Teifcammern and thus becomes the aim of the invention achieves that the available discharge capacity can be varied as little as possible over the largest possible period of time.

According to a development, the pumps and valves are connected to a control circuit with which the volume flows of the electrolytes of the sets present in the chamber arrangements and their solubility are controlled as a function of the molar ratio.

Depending on the type of electrolytes used, different molar ratios result for the electrochemical reactions. In addition, the salts of the electrolytes can show a different solution behavior in water. The specified dependence of the control of the volume flows of the electrolytes ensures that on the one hand the necessary for the electrochemical reactions ratios of electrolytes are complied with and on the other hand, the solution of the salts of a supersaturated solution and water is led to a saturated solution, so that the optimum concentration is maintained for the electrochemical reactions.

Water removal stations in the form of an osmosis device and between the dispensing electrolyte tanks and electrolyte inlets of the chamber arrangements are preferably arranged between electrolyte drains of the chamber arrangements and the receiving electrolyte tanks in the form of mixing devices, and water drains of the osmosis devices and water inlets of the mixing devices are connected to a common intermediate water tank.

By this measure, the water content can be limited to the amount that is absolutely necessary for the operation of the redox accumulator. The volume and weight of the Redoxakkumulatoranlage can be limited to a minimum, which is particularly advantageous for mobile operation. In an osmo- Adequate separation of water and salt can be achieved by means of existing or generated pressure, so that this type of dehydration is practicable. The water enrichment in a mixing device makes it possible to produce a solution with a specific degree of dilution from a supersaturated solution.

Saturated supersaturated salt solutions and water are used to produce saturated salt solutions, which ensure optimal concentration and utilization of the salts for the discharge performance.

Furthermore, the dispensing electrolyte tanks may have external refueling connections and the receiving electrolyte tanks may have external defrosting connections.

This makes it possible to repeatedly put the capacity of the Redoxakkumulatoranlage in the charged state, but also replace by side effects contaminated electrolyte to fresh electrolyte.

As an alternative to replacing discharged and charged salts, the electrical potentials of the partial chamber pairs present at the electrode pairs can be connected in parallel in a charging phase.

As a result, the entire volume of the pair of chamber arrangements consisting of the volumes of the respective sub-chambers, including their electrodes, is available for the charging process.

The invention will be explained with reference to embodiments, which is illustrated in the drawings.

In the drawing show: 1 shows a first part of a redox accumulator system with a pair of chamber arrangements in which the salts of the first type dissolved in the electrolyte are successively electrochemically reduced and therefore supply electrical energy. FIG. 2 shows a second part of a redox accumulator system with a pair of chamber arrangements. which corresponds to the process in Fig. 1 and contains a salt of the second kind,

3 is a plan view of a Redoxakkumulator the Redoxakkumulatoranlage in horizontal section,

4 shows an osmotic device with which supersaturated salt solutions and water can be recovered for reuse, FIG. 5 shows a mixing device for the permanent supply of fully saturated saline solution,

6 is a functional diagram of the valve switch shown in Fig. 1 and Fig. 2,

7 shows a control circuit with representation of the input signals to be processed and output signals to be provided.

Fig. 1 shows a first part of a redox accumulator system with a pair of chamber assemblies A and Fig. 2 shows a second part of a redox accumulator system with a pair of chamber assemblies B. A related construction of the chamber assemblies A and B is shown in connection with Fig. 3. This shows a Top view of the Redoxakumumulator in horizontal section, with all chamber arrangements A and B, which can be momentarily active when needed. The chamber arrangements A comprise sub-chambers A0 to A4, whereby connect to the sides of the central sub-chamber AO sub-chambers A1 and A2 and to the sub-chambers A1 and A2 in turn Teifcammem A3 and A4. The partial chamber AO is connected to an electrolyte line aO, while the last partial chambers A3, A4 are each connected to electrolyte lines a1, a2. The adjoining subchambers are flow-connected by electrolyte overflows UE. The same applies to the chamber arrangements B.

The electrolyte overflow UE are arranged in their height so that the electrolyte can always flow from the smaller part of the chamber into the next larger. In addition, overflows are in pairs at the sub-chambers shown in the chamber arrangements A and B at the same heights, so that equal-sized sub-chambers are also refilled immediately. All overflows are provided with a water-repellent layer containing, for example, nanoparticles, so that no electrical leakage currents can occur between the sub-chambers. All sub-chambers of the chamber assemblies A and B are electrically isolated from each other and have their own electrodes. The two Teilkammem AO and BO are the smallest and have on unloading the largest ratio of charged salt to discharged salt. In contrast, the Teilkammem A1 and A2 and A3 and A4 are each larger. The same applies to the chamber arrangements B.

The ratio of charged salt to discharged salt is smaller in each case in the partial chambers following the smallest partial chambers AO and BO. Therefore, the reaction area of the electrodes and the volume of Teilkammem must increase accordingly. With the division of the chamber arrangements A and B in Teilkammem and increasing in the flow direction of the electrolyte size is achieved that a discharge is possible in which all partial chamber pairs constantly deliver about the same power. The electrical switch S1 to S8 shown in Fig. 3 allow an electrical series connection of all electrodes All chamber assemblies A and B to a plus and minus pole, which is a high terminal voltage for electrical consumers available.

Pumps PA, PB and valves 111 A, U2A, U3A; U4A, U1B, U2B, U3B U4B are connected to a control circuit SS shown in Fig. 7, whereby volumetric flows of the electrolyte in each part of the pair of chamber assemblies are controlled depending on the molar ratio of the salts present in the chamber assemblies A and B and their solubility and also an exchange of the salts is controlled in preparation for a longer charging phase of the redox accumulator system.

For this purpose, there is an inlet aO to the partial chamber AO and an inlet bO to the partial chamber BO. The associated processes of the electrolytes are designated a1 and a2 for the chamber arrangements A in FIG. 1 and FIG. 3, and b1 and b2 for the chamber arrangements B in FIG. 2 and FIG. 3. For the controlled transport of the electrolyte liquids, as shown in FIG. 1 and FIG. 2, pumps PA and PB are provided which are driven by electric motors EMA and EMB. The pump PA transports the effluent electrolyte fluid of the chamber assembly A and the pump PB that of the chamber assembly B.

The respective electric motor can turn a spindle leading into the piston of the pump to the left or to the right, so that the piston moves back and forth. After the filling phase of the piston cylinder with electrolyte liquid, it is supplied to an osmosis device OSA for the chamber arrangement A and OSB for the chamber arrangement B. The piston frequency of the piston pumps PA and PB is controlled by the control circuit SS shown in FIG. 7 in such a way that the required molar ratio of the salts present in the chambers A and B and their solubility are taken into account, so that the optimal achievable discharge or charging power is always guaranteed Electrolytes with discharged salts get into the discharge tank ATA, ATB and electroltes with charged salts are taken from feed tanks ZTA, ZTB. A control of the connecting lines is Upper switch, namely valve switch U1A, U1B and U2A, U2B which can be switched between charging, discharging and off.

The redox accumulator can be alternatively discharged, charged and switched off. The electrical charging can be done by an internal or external power source. As an internal power source is z. Example, an electric machine, which is operated for driving purposes as an electric motor and for deceleration purposes (braking) as a generator and during the deceleration phase recovered electrical energy for charging the Redoxakkumulators provides, and a thermal converter. In principle, the electrical supply network or a self-sufficient generator can be used as an external power source. Self-sufficient generators are preferably those which use renewable energy sources, such as solar generators, biomass generators, wind generators and also thennic converters, as described in DE 102005025028 A1. In addition, external charging is possible and also provided by replacing the tank contents. This requires two defrosting ALA, ALB and two refueling connections ZLA, ZLB. Discharged supersaturated brine solutions must be pumped out and charged supersaturated brine solutions must be added. In Fig. 1 and Fig. 2, the necessary changeover U3A, U3B and in Fig.6 their positions for the replacement of the solutions are shown.

During the electrical charge between the memories ATA, ATB and ZTA, ZTB in the Redoxakkumulatoranlage the switches S1 to S8 shown in Fig. 3 are switched so that the positive electrodes of all chamber assemblies B and the negative electrodes of the chamber assemblies A are connected in parallel. When the electronic controller indicated in Fig. 7 has detected above the port RA that the salts in the chamber assemblies A and B are in the charged state, the pumps PA and PB are activated until all the chamber assemblies A and B are empty. For this, the valve switches U2A and U2B as well as also U4A and U4B must be set to _" electrical charge" and after completion they should be "off." Then all chamber arrangements A and B are refilled by setting the valve switches U1A and U1B to "charge" The two described processes can continue to run alternately during the internal and external electrical charging until the drain tank ATA is empty and the supply tank ZTA is full.

With the electronic control SS indicated in FIG. 7, the control and regulating processes are possible via electronic measured value detectors, if necessary also with the aid of sensors, which allow operation of the redox accumulator system both manually and in terms of tank capacity and electrical charging possibilities also automatically enable optimum energy use.

Any electrical energy recovered from negative acceleration energy can and should be used to charge the reservoirs contained in the redox accumulator Only in the short charging time that occurs will switches S1 to S8 be switched to charging The salts in subchambers A1 to A4 and B1 to B4 will not be exchanged

The osmosis device OSA, OSB already mentioned and illustrated in FIG. 1 and FIG. 2 is intended to keep the water content as small as possible, in particular for mobile operation of the redox accumulator. The proportion of water which is absolutely necessary for the operation of the redox accumulator results from the water content saturated and supersaturated salt solutions in the redox accumulator in the tanks and osmotic devices as well as in the pipes. Apart from a mostly high separation of water and salt by energy supply, a sufficient separation by means of pressure by osmosis is possible.

The main component of the osmotic device is a semipermeable film which is permeable to water and has a blocking effect on salt molecules. FIG. 4 shows a vertical section of an osmotic device. The structure is the same for the chamber arrangements A as for the chamber arrangements B. In a vessel there are meanderformig running flat lines containing semi-permeable films SF on both sides. The line has an inlet ZL and a drain AL. From the saturated salt solution GEL at the inlet, which is indicated in section AB, the supersaturated salt solution UEL which is obtained in section AB is produced by the osmosis at the outlet. The water which has passed through the semipermeable films leaves the outlet via the water outlet WA and flows into intermediate water tanks WSA and WSB. The supersaturated brine solution is directed from outlet AL to dedicated tanks. From the horizontal sections AB and CD in FIG. 4, it can be seen from the increasing shading that the salt concentration of the electrolyte liquid increases considerably from the inlet to the outlet.

In Fig. 5 it is shown how the supersaturated salt solution in the respective tanks can be recovered with water via an inlet M2 and a valve V2 to a saturated solution L2 for the redox accumulator. For this purpose, an inlet 1 to an ascending pipe R is attached to the bottom of the tank. Via the backflow valve V1, the tube fills with supersaturated saline solution L1 up to the level in the tank. With the water supply, a saturated saline solution 12 is automatically generated according to the principle of Le Chatelier (p = c RT, p - »pressure, c -> concentration, R -> gas constant, T -> temperature degree K). The valve V2 closes the water supply automatically when the drain of the saturated saline solution is stopped over the drain 3 because it is connected to a float W which is moved by the saline solution L2. The backflow valve V1 prevents the tank from filling up with water when it is almost empty. FIG. 6 shows a functional diagram of the valve switch shown in FIG. 1 and FIG. The columns show the valve switches U1A and U1B for the positions Charging, Off, Discharging, the valve switches U2A and U2B for the positions Charging, Off, Discharging and the valve switches U3A and U3B for the positions Off and Refueling as well as the position of the valve selector U4A and U4B with electric charge. The lines show the possible four functions, namely internal discharging, electric charging, external refueling and refueling, deactivation. The dots between columns and rows show the state of the valve switches in the corresponding functions. Fig. 7 shows a schematic representation of the control circuit SS with input variables and output variables. Input variables are, in addition to a manual control ME control signals RS, which optimally provide the electrical output power PV. The input and output signals RA control the electrical energy supply EQ during all electrical charging operations.

Output variables are the valve switching controls VS (FIG. 1 and FIG. 2), the pump controls ESA and the switching control of the electrical change-over switches S1 to S8 (FIG. 3).

The tasks of the control circuit SS shown in FIG. 7 result from the functional conditions and the possible adjustable operating modes of the system. The methods of the control and regulating processes are known. The electronics required for this purpose are likewise known and usable.

Claims

A redox accumulator system comprising a redox accumulator having a pair of chamber assemblies containing, as electrolytes, aqueous solutions of salts in different oxidation states, a pair of electrode assemblies for delivering electrical energy during discharge, and supplying electrical energy during charging associated with the pair of the chamber - Associated with, and an intermediate electrode assembly between the two chamber assemblies of the pair, and consisting of external pairs of electrolyte tanks with electrolytes, pairs of electrolyte conduits between the chamber assemblies and electrolyte tanks and a controllable pair of pumps and valves, characterized in that the chamber assemblies of the pair an equal number of sub-chamber pairs comprise, that separately for each part of the pair, an electrolyte line is connected to a first sub-chamber that the first sub-chamber, a second sub-chamber and in a similar manner further na adjoining sub-chambers adjoin that another electrolyte line is connected to the last sub-chamber, that the adjoining Teilkammem are flow connected by Elektrolytüberläufe that during a Entadephase in the first sub-chamber, the ratio of the charged salts to the uncharged salts of the electrolyte largest and in the subsequent Teilkammem each smaller than in the respective preceding Teilkammem that the volumes of Teilkammem and reaction surfaces of the electrode assemblies and intermediate electrode assembly increase starting from the first sub-chamber and ending with the last sub-chamber that between the electrolyte tank and the chamber assemblies from sub-chamber to sub-chamber by means of the pump and valves controlled flow of the electrolytes is present, that the electrode arrangements and the Zwischenelektroclenanordnung each have a separate pair of electrodes and a separate intermediate electrode per Teilkammer- Have pair and that the pending on the electrode pairs electrical potentials of the sub-chamber pairs are connected in parallel in a Entadephase in series and in a charging phase.

2. Redoxakkumulatoranlage according to claim 1, characterized in that the pumps and valves are connected to a control circuit and volume flows of the electrolytes in each part of the pair of chamber assemblies depending on the observed molar ratio of the salts present and their solubility is controlled.

3. Redoxakkumulatoranlage according to claim 1 or 2, characterized in that are arranged between Elektrotytabläufen the chamber assemblies and the receiving electrolyte tanks dewatering stations in the form of each osmosis device and between the dispensing electrolyte tanks and Elektrolytzulaufen the chamber assemblies Wasseranreicherungsstationen in the form of mixing devices and that water drains the osmosis devices and water supplies the mixing devices are connected to intermediate water tanks.

4. Redoxakkumulatoranlage according to any one of claims 1 to 3, characterized in that the electrolyte to the Redoxakkumulator donating electrolyte tanks have external Betankanschlüsse and the electrolyte from the Redoxakkumulator receiving electrolyte tanks external Enttankanschlüsse.

5. Redoxakkumulatoranlage according to one of claims 1 to 3, characterized in that in a charging phase, the pending on the electrode pairs electrical potentials of the partial chamber pairs are connected in parallel.