CN219226328U - OCV battery for flow battery - Google Patents

Abstract

The utility model relates to an OCV battery for a flow battery and an OCV monitoring method for the flow battery, wherein the OCV battery comprises three electrode chambers, and the three electrode chambers comprise a first end plate, a first current collector, an electrode positioned in a through hole in the middle of an annular electrode frame, a diaphragm, a third current collector, an electrode positioned in the through hole in the middle of the first annular electrode frame, a fourth current collector, a diaphragm, an electrode positioned in the through hole in the middle of the annular electrode frame, a second current collector and a second end plate which are sequentially stacked. The battery adopted by the monitoring method is the OCV battery. According to the OCV battery and the monitoring method, the open-circuit voltage of two half batteries of the flow battery can be measured at the same time, and the open-circuit voltage of the whole battery is calculated according to the open-circuit voltage of the two half batteries. The constant potential solution is replaced regularly, so that the accuracy of the OCV value of the flow battery can be ensured. Meanwhile, the utility model has simple process, simple and convenient operation and low cost, and can ensure that the battery can operate efficiently and stably for a long time.

Description

OCV battery for flow battery

Technical Field

The utility model relates to the field of flow batteries, in particular to an OCV battery for a flow battery and a monitoring method.

Background

The flow battery has the outstanding advantages of independent and adjustable system capacity and power, quick response, safety, reliability, environmental friendliness, long cycle life, easiness in maintenance and regeneration and the like, so that the flow battery becomes one of the most development prospect technologies in large-scale energy storage of renewable energy power generation, peak clipping and valley filling of a power grid, emergency and standby power stations and the like.

When designing flow batteries and systems, it is necessary to design OCV batteries to monitor the state of the electrolyte and ensure that the electrolyte is in a controllable state. When the flow battery operates, active substances in the electrolyte can migrate through the diaphragm, and due to factors such as different migration rates of the active substances, the valence state of the electrolyte of the anode and the cathode is deviated after the battery operates for a long time, and the state of the electrolyte cannot be truly reflected by the obtained voltage value when the OCV battery designed by the existing scheme is used for measuring the electrolyte with unbalanced valence state. Therefore, the novel OCV battery and the monitoring method are designed and invented, and play an important role in the reliability of long-term operation of the system.

Disclosure of Invention

The utility model aims to solve the problems and provide an OCV battery for a flow battery and an OCV monitoring method for the flow battery.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

an OCV battery for a flow battery comprises a first end plate, a first current collector, an electrode, a diaphragm, a third current collector, an electrode, a fourth current collector, a diaphragm, an electrode, a second current collector and a second end plate which are sequentially stacked, wherein the electrode is positioned in a through hole in the middle of an annular electrode frame;

the annular electrode frame is of a flat plate-shaped structure with a through hole penetrating through the surfaces of the two side plate bodies in the middle, and the flat plate-shaped electrode is arranged in the through hole in the middle of the annular electrode frame; two corresponding through holes are respectively formed in the first end plate and the first current collector, and the second end plate and the second current collector, so that two groups of channels which are respectively communicated with the through holes in the middle of the annular electrode frame adjacent to the first current collector or the second current collector are formed and are respectively used as an electrolyte inlet channel and an electrolyte outlet channel;

the first annular electrode frame is of a flat plate-shaped structure, the middle part of the flat plate-shaped structure is provided with a through hole penetrating through the surfaces of the two side plates, and the outer wall surfaces of the two corresponding side edges of the first annular electrode frame are respectively provided with a through hole A and a through hole B which are communicated with the through hole in the middle of the first annular electrode frame and are respectively used as an inlet channel and an outlet channel of liquid;

the third current collector and the fourth current collector are respectively of two sheet structures or annular structures, are respectively arranged on the two side surfaces of the electrode in the through hole in the middle of the first annular electrode frame, and are respectively attached to the two side surfaces of the electrode.

And a lug is respectively extended at the side edges of the third current collector and the fourth current collector in a direction parallel to and far away from the surface of the current collector, and extends to the outside of the electrode frame through the side edge of the first annular electrode frame.

Grooves penetrating through the middle through hole and the side wall surfaces of the four peripheral edges of the through hole are respectively formed in the two side surfaces of the first annular electrode frame;

the liquid inlet channel and the liquid outlet channel are positioned on the side surface of the electrode frame; after the collecting lugs are sealed in the grooves, part of the collecting lugs are leaked outside the side surfaces of the electrode frame.

The components of the battery are sequentially stacked and sealed to form an OCV battery; the electrodes on the two sides of the diaphragm are respectively arranged oppositely on the two sides of the diaphragm;

the OCV battery comprises three electrode chambers, wherein two electrode chambers at two sides are respectively formed by surrounding a first current collector or a second current collector, an annular electrode frame and a diaphragm; the middle electrode chamber is surrounded by two diaphragms and a first annular electrode frame therebetween.

The first to fourth current collectors are made of metal or conductive nonmetallic materials.

According to the OCV monitoring method of the flow battery, an OCV battery structure is adopted, positive electrolyte and negative electrolyte of the flow battery are respectively introduced into two outer electrode cavities of the OCV battery, which are close to the first end plate and the second end plate, through electrolyte inlet channels and electrolyte outlet channels on the first end plate and the second end plate, so that the positive electrolyte and the negative electrolyte of the flow battery respectively flow through two electrodes, which are close to the end plates;

introducing the solution outside the battery into the through hole in the middle of the first annular electrode frame through the liquid inlet channel on the first annular electrode frame, and flowing out through the liquid outlet channel to enable the solution to flow through the electrode in the through hole in the middle of the first annular electrode frame;

by monitoring the voltage between the first current collector and the third current collector, and the voltage between the fourth current collector and the second current collector, respectively, the OCV of the flow battery is obtained.

The solution is a solution with a constant potential value, is filled in the solution storage tank, and flows back and forth in the first annular electrode frame and the solution storage tank through the liquid pump. The constant solution is one or more of solution with macromolecules, electrolyte of a flow battery body, cadmium and cadmium sulfate, copper and copper oxide, and lead.

The flow battery includes, but is not limited to, all-vanadium flow batteries, sodium polysulfide bromine flow batteries, iron-chromium flow batteries, all-chromium flow batteries, and vanadium bromine flow batteries.

And respectively monitoring the voltage difference between the first current collector and the third current collector and the voltage difference between the fourth current collector and the second current collector to obtain the OCV value of the tested flow battery.

The beneficial results of the utility model are:

1) The utility model provides an OCV battery structure and a detection method, which can simultaneously measure open-circuit voltages of two half batteries of a flow battery and calculate the charge state of electrolyte according to the open-circuit voltage values of the half batteries. And calculates the open circuit voltage of the full cell based on the open circuit voltages of the two half cells.

2) The constant potential solution is replaced regularly, so that the accuracy of the OCV value of the flow battery measured during long-term operation of the battery can be ensured, and the accuracy of the calculated state of charge of the electrolyte can be ensured.

3) The utility model has simple process, simple and convenient operation and low cost, and can ensure that the battery can operate efficiently and stably for a long time.

Drawings

Fig. 1 is a structural diagram of an OCV battery according to the present utility model, wherein: 1-end plates, 2-current collectors, 3-annular electrode frames, 4-diaphragms and 5-first annular electrode frames;

fig. 2 is a structural view of a first ring-shaped electrode frame assembly, in which: 5-first annular electrode frame, 6-third current collector, 7-fourth current collector, 8-liquid inlet, 9-liquid outlet.

Detailed Description

The following examples are further illustrative of the utility model and are not intended to limit the scope of the utility model.

Example 1

Preparing a first end plate, a second end plate, an annular electrode frame, a first annular electrode frame, electrodes, a diaphragm, first to fourth current collectors, sealing gaskets, fastening screws and the like, wherein the electrodes are made of carbon felt, the size is 6cm x 8cm, the electrode frame is a PVC plate with a through hole in the middle, the size of the electrode frame is 10cm x 12cm, the thickness of the electrode frame is 8mm, the size of the through hole is 6cm x 8cm, the edge of the through hole is 2cm away from the outer edge of the electrode frame, and a liquid inlet 8 and a liquid outlet 9 with the diameters of 3mm are formed in the outer wall surface of the side edge of the first annular electrode frame. Meanwhile, grooves penetrating through the middle through hole and the side wall surfaces of the four peripheral edges of the through hole are respectively formed in the two side surfaces of the first annular electrode frame, the third current collector and the fourth current collector are of sheet structures, a lug is respectively arranged at the edges of the side edges along the directions parallel to and far away from the surfaces of the current collectors, the lug penetrates through the side edges of the first annular electrode frame and extends out of the electrode frame, and the third current collector and the fourth current collector clamp the carbon felt in the first annular electrode frame.

The components are sequentially stacked and sealed to form the OCV battery, wherein the stacking sequence is as follows: the electrode comprises a first end plate, a first current collector, an annular electrode frame 3, a first electrode, a diaphragm 4, a second electrode, a third current collector 6, a first annular electrode frame 5, a fourth current collector 7, a second electrode, a diaphragm 4, a first electrode, an annular electrode frame 3, a second current collector and a second end plate.

The OCV cell is divided into 3 chambers according to electrode chambers. When the OCV battery is in operation, constant potential liquid outside the battery is introduced into the electrode through the liquid inlet 8 on the first annular electrode frame, flows through the carbon felt, and then flows out of the battery through the liquid outlet 9 on the electrode frame with a special structure.

The OCV battery is connected into an all-vanadium redox flow battery system, wherein the positive electrode electrolyte and the negative electrode electrolyte of the all-vanadium redox flow battery are respectively introduced into two electrode chambers at the outer side close to an end plate, and sulfuric acid aqueous solution containing 1.5mol/L V (III) ions is introduced into the middle chamber, at the moment, the voltage between the first current collector and the third current collector and the voltage between the fourth current collector and the second current collector can be respectively monitored, and the voltages are respectively 1.123V and-0.218V, so that two open-circuit voltage values of the positive electrode and the negative electrode are obtained. And further, the OCV value of the all-vanadium redox flow battery is 1.123V- (-0.218V) =1.341V. Based on the voltage value of half cell, the SOC of the positive electrolyte can be calculated _pos State of charge SOC of negative electrode electrolyte _neg 。

Comparative example 1

The conventional OCV battery structure only comprises two electrode chambers (the two electrode chambers corresponding to the two sides of the embodiment of the utility model are respectively formed by surrounding a current collector, an annular electrode frame and a diaphragm, only comprises one diaphragm, and is composed of a first end plate, a first current collector, an annular electrode frame 3, a first electrode, a diaphragm 4, a first electrode, the annular electrode frame 3, a second current collector and a second end plate), and the two chambers are respectively introduced into positive and negative electrolyte of a battery to be tested to detect the voltage between the two current collectors of the OCV battery.

With the conventional OCV battery structure, only the OCV value was measured in the all-vanadium redox flow battery system of example 1, and the measured OCV value was 1.341V. The state of charge SOC of the positive electrolyte and the negative electrolyte cannot be calculated, respectively, because of the absence of half-cell voltage values.

Example 2

Preparing a first end plate, a second end plate, an annular electrode frame, a first annular electrode frame, electrodes, a diaphragm, first to fourth current collectors, sealing gaskets, fastening screws and the like, wherein the electrodes are made of carbon felt, the size is 6cm x 8cm, the electrode frame is a PVC plate with a through hole in the middle, the size of the electrode frame is 10cm x 12cm, the thickness of the electrode frame is 8mm, the size of the through hole is 6cm x 8cm, the edge of the through hole is 2cm away from the outer edge of the electrode frame, and a liquid inlet 8 and a liquid outlet 9 with the diameters of 3mm are formed in the outer wall surface of the side edge of the first annular electrode frame. Meanwhile, grooves penetrating through the middle through hole and the side wall surfaces of the four peripheral edges of the through hole are respectively formed in the two side surfaces of the first annular electrode frame, the third current collector and the fourth current collector are of annular structures, a lug is respectively arranged at the edges of the side edges along the directions parallel to and far away from the surfaces of the current collectors, the lug penetrates through the side edges of the first annular electrode frame and extends out of the electrode frame, and the third current collector and the fourth current collector clamp the carbon felt in the first annular electrode frame.

The components are sequentially stacked and sealed to form the OCV battery, wherein the stacking sequence is as follows: the electrode comprises a first end plate, a first current collector, an annular electrode frame 3, a first electrode, a diaphragm 4, a second electrode, a third current collector 6, a first annular electrode frame 5, a fourth current collector 7, a second electrode, a diaphragm 4, a first electrode, an annular electrode frame 3, a second current collector and a second end plate.

The OCV cell is divided into 3 chambers according to electrode chambers. When the OCV battery is in operation, constant potential liquid outside the battery is introduced into the electrode through the liquid inlet 8 on the first annular electrode frame, flows through the carbon felt, and then flows out of the battery through the liquid outlet 9 on the electrode frame with a special structure.

The OCV battery is connected into an iron-chromium flow battery system, wherein positive electrolyte and negative electrolyte of the iron-chromium flow battery are respectively introduced into two electrode chambers at the outer side close to an end plate, sulfuric acid aqueous solution containing 1.5mol/LCr (III) ions is introduced into the middle chamber, and at the moment, the voltage between a first current collector and a third current collector and the voltage between a fourth current collector and a second current collector are respectively monitored to be 0.843V and-0.328V, so that two open-circuit voltage values of the positive electrode and the negative electrode are obtained. And further, the OCV value of the ferrochrome flow battery is 0.843V- (-0.328V) =1.171V. Based on the voltage value of half cell, the SOC of the positive electrolyte can be calculated _pos State of charge SOC of negative electrode electrolyte _neg 。

(two electrode chambers corresponding to two sides of the embodiment of the utility model are respectively formed by surrounding a current collector, an annular electrode frame and a diaphragm, and only comprise one diaphragm, and are composed of a first end plate, a first current collector, the annular electrode frame 3, a first electrode, the diaphragm 4, a first electrode, the annular electrode frame 3, a second current collector and a second end plate)

Comparative example 2

The conventional OCV battery structure only comprises two electrode chambers, and positive and negative electrolyte of a battery to be detected are respectively introduced into the two chambers to detect the voltage between two current collectors of the OCV battery.

With the conventional OCV battery structure, only the OCV value of the iron chromium flow battery system of example 2 was measured, and the measured OCV value was 1.171V. The state of charge SOC of the positive electrolyte and the negative electrolyte cannot be calculated, respectively, because of the absence of half-cell voltage values.

Example 3

Preparing a first end plate, a second end plate, an annular electrode frame, a first annular electrode frame, electrodes, a diaphragm, first to fourth current collectors, sealing gaskets, fastening screws and the like, wherein the electrodes are made of carbon felt, the size is 6cm x 8cm, the electrode frame is a PVC plate with a through hole in the middle, the size of the electrode frame is 10cm x 12cm, the thickness of the electrode frame is 8mm, the size of the through hole is 6cm x 8cm, the edge of the through hole is 2cm away from the outer edge of the electrode frame, and a liquid inlet 8 and a liquid outlet 9 with the diameters of 3mm are formed in the outer wall surface of the side edge of the first annular electrode frame. Meanwhile, grooves penetrating through the middle through hole and the side wall surfaces of the four peripheral edges of the through hole are respectively formed in the two side surfaces of the first annular electrode frame, the third current collector and the fourth current collector are of annular structures, a lug is respectively arranged at the edges of the side edges along the directions parallel to and far away from the surfaces of the current collectors, the lug penetrates through the side edges of the first annular electrode frame and extends out of the electrode frame, and the third current collector and the fourth current collector clamp the carbon felt in the first annular electrode frame.

The components are sequentially stacked and sealed to form the OCV battery, wherein the stacking sequence is as follows: the electrode comprises a first end plate, a first current collector, an annular electrode frame 3, a first electrode, a diaphragm 4, a second electrode, a third current collector 6, a first annular electrode frame 5, a fourth current collector 7, a second electrode, a diaphragm 4, a first electrode, an annular electrode frame 3, a second current collector and a second end plate.

The OCV cell is divided into 3 chambers according to electrode chambers. When the OCV battery is in operation, constant potential liquid outside the battery is introduced into the electrode through the liquid inlet 8 on the first annular electrode frame, flows through the carbon felt, and then flows out of the battery through the liquid outlet 9 on the electrode frame with a special structure.

The OCV battery is connected into a sodium polysulfide bromine flow battery system, wherein the positive electrode electrolyte and the negative electrode electrolyte of the all-vanadium flow battery are respectively introduced into two electrode chambers at the outer side close to an end plate, and a solution containing 1.3 mol/sodium polysulfide is introduced into the middle chamber, at the moment, the voltage between a first current collector and a third current collector and the voltage between a fourth current collector and a second current collector are respectively monitored to be 1.254V and-0.426V, so that two open-circuit voltage values of the positive electrode and the negative electrode are obtained. And further, the OCV value of the sodium polysulfide bromine flow battery is 1.254V- (-0.426V) =1.68V. Based on the voltage value of half cell, the SOC of the positive electrolyte can be calculated _pos State of charge SOC of negative electrode electrolyte _neg 。

Comparative example 3

The conventional OCV battery structure only comprises two electrode chambers (the two electrode chambers corresponding to the two sides of the embodiment of the utility model are respectively formed by surrounding a current collector, an annular electrode frame and a diaphragm, only comprises one diaphragm, and is composed of a first end plate, a first current collector, an annular electrode frame 3, a first electrode, a diaphragm 4, a first electrode, the annular electrode frame 3, a second current collector and a second end plate), and the two chambers are respectively introduced into positive and negative electrolyte of a battery to be tested to detect the voltage between the two current collectors of the OCV battery.

With the conventional OCV battery structure, only the OCV value can be measured by accessing the sodium polysulfide bromine flow battery system of example 3, and the measured OCV value is 1.68V. The state of charge SOC of the positive electrolyte and the negative electrolyte cannot be calculated, respectively, because of the absence of half-cell voltage values.

Claims (5)

1. OCV battery for flow battery, its characterized in that: the electrode assembly comprises a first end plate, a first current collector, an electrode, a diaphragm, a third current collector, an electrode, a fourth current collector, a diaphragm, an electrode and a second current collector which are sequentially stacked, wherein the electrode is positioned in a through hole in the middle of an annular electrode frame;

the annular electrode frame is of a flat plate-shaped structure with a through hole penetrating through the surfaces of the two side plate bodies in the middle, and the flat plate-shaped electrode is arranged in the through hole in the middle of the annular electrode frame; two corresponding through holes are respectively formed in the first end plate and the first current collector, and the second end plate and the second current collector, so that two groups of channels which are respectively communicated with the through holes in the middle of the annular electrode frame adjacent to the first current collector or the second current collector are formed and are respectively used as an electrolyte inlet channel and an electrolyte outlet channel;

the first annular electrode frame is of a flat plate-shaped structure, the middle part of the flat plate-shaped structure is provided with a through hole penetrating through the surfaces of the two side plates, and the outer wall surfaces of the two corresponding side edges of the first annular electrode frame are respectively provided with a through hole A and a through hole B which are communicated with the through hole in the middle of the first annular electrode frame and are respectively used as an inlet channel and an outlet channel of liquid;

the third current collector and the fourth current collector are respectively of two sheet structures or annular structures, are respectively arranged on the two side surfaces of the electrode in the through hole in the middle of the first annular electrode frame, and are respectively attached to the two side surfaces of the electrode.

2. The OCV battery of claim 1 wherein:

and a lug is respectively extended at the side edges of the third current collector and the fourth current collector in a direction parallel to and far away from the surface of the current collector, and extends to the outside of the electrode frame through the side edge of the first annular electrode frame.

3. The OCV battery of claim 1 wherein:

grooves penetrating through the middle through hole and the side wall surfaces of the four peripheral edges of the through hole are respectively formed in the two side surfaces of the first annular electrode frame;

the liquid inlet channel and the liquid outlet channel are positioned on the side surface of the electrode frame; after the collecting lugs are sealed in the grooves, part of the collecting lugs are leaked outside the side surfaces of the electrode frame.

4. The OCV battery of claim 1 wherein:

the components of the battery are sequentially stacked and sealed to form an OCV battery; the electrodes on the two sides of the diaphragm are respectively arranged oppositely on the two sides of the diaphragm;

the OCV battery comprises three electrode chambers, wherein two electrode chambers at two sides are respectively formed by surrounding a first current collector or a second current collector, an annular electrode frame and a diaphragm; the middle electrode chamber is surrounded by two diaphragms and a first annular electrode frame therebetween.

5. The OCV battery of claim 1 wherein: the first to fourth current collectors are made of metal or conductive nonmetallic materials.

Images