CN109065916B

CN109065916B - Slurry energy storage system

Info

Publication number: CN109065916B
Application number: CN201810904225.8A
Authority: CN
Inventors: 王志兴; 刘越; 莫文彬; 王接喜; 李新海; 郭华军; 胡启阳; 彭文杰; 颜果春
Original assignee: Central South University
Current assignee: Central South University
Priority date: 2018-08-09
Filing date: 2018-08-09
Publication date: 2020-07-10
Anticipated expiration: 2038-08-09
Also published as: CN109065916A

Abstract

The invention discloses a slurry energy storage system, which comprises a storage structure, an electrochemical reaction structure and a material circulating system, wherein the material circulating system comprises an electrolyte circulating system and a slurry circulating system; the material storage structure is arranged above the electrochemical reaction structure and is communicated with the electrochemical reaction structure, one end of the material circulation system is communicated with the material storage structure, and the other end of the material circulation system is communicated with the electrochemical reaction structure; when the device works, the deposition type active slurry in the storage structure enters the electrochemical reaction structure from the storage structure under the action of a driving force for reaction, is discharged and mixed with electrolyte to form suspension type active slurry, returns to the storage structure through the slurry circulating system, and is converted into the deposition type active slurry again in the storage structure; the active slurry has two forms of deposition type and suspension type, exists in the form of the deposition type active slurry in the processes of storage, charging and discharging, and has higher bulk density and energy density, and better conductivity and rate capability.

Description

Slurry energy storage system

Technical Field

The invention relates to the field of chemical energy storage batteries, in particular to a slurry energy storage system.

Background

The semi-solid lithium ion flow battery is an electrochemical energy storage battery technology which is newly developed, integrates the advantages of the lithium ion battery and the flow battery, and is a novel secondary battery which has independent output power and energy storage capacity, large energy density, lower cost and high safety.

For example, a lithium ion flow battery in the prior art uses an active material applied in a lithium ion battery, which exists in the form of solid particles, and forms a suspension with an electrolyte through a binder, and flows in a flow channel. But it has the following disadvantages: 1) The contradiction exists between the fluidity of the suspension and the solid content of the suspension, the solid content of the electrolyte needs to be increased when the overall energy density is improved, but the fluidity of the electrolyte is deteriorated, if the solid content is low, the energy density is greatly reduced, the overall conductivity of the electrode is low, and the electrode is polarized greatly in the reaction process; 2) The stability of the suspension is difficult to ensure, and local sedimentation is very easy to form to block a flow passage and a diaphragm; thus it greatly increases the difficulty and production cost of the equipment design and manufacture.

In view of the above, it is desirable to provide a slurry energy storage system that has a high energy density, is safe, reliable, and is low cost.

Disclosure of Invention

Therefore, the invention provides a slurry energy storage system which comprises a storage structure, an electrochemical reaction structure and a material circulating system, wherein the material circulating system comprises an electrolyte circulating system and a slurry circulating system; the material storage structure is communicated with the electrochemical reaction structure, and the material circulating system is communicated with the material storage structure and the electrochemical reaction structure; the during operation is located deposit type active slurry in the storage structure is under the drive power effect, by the storage structure gets into after the electrochemical reaction structure reaction, and discharge with electrolyte mixes and forms suspension type active slurry, and passes through slurry circulation system returns the storage structure convert deposit type active slurry again in the storage structure.

The storage structure comprises at least one group of storage components, each storage component comprises an anode storage tank and a cathode storage tank, and the anode storage tank and/or the cathode storage tank are/is set as a deposition type active slurry storage tank; the slurry circulation system comprises at least one group of slurry circulation components, and the slurry circulation components comprise positive slurry circulation and/or negative slurry circulation; when the positive electrode storage tank is set as a deposition type active slurry storage tank and the slurry circulation assembly comprises a positive electrode slurry circulation system, one end of the positive electrode slurry circulation system is communicated with an outlet of a positive electrode cavity of the electrochemical reaction structure and the electrolyte circulation system through a first junction station, and the other end of the positive electrode slurry circulation system is communicated with a slurry inlet of the positive electrode storage tank; when the cathode storage tank is set to be a deposition type active slurry storage tank and the slurry circulation assembly comprises a cathode slurry circulation, one end of the cathode slurry circulation is communicated with an outlet of a cathode cavity of the electrochemical reaction structure and the electrolyte circulation system through a second confluence device, and the other end of the cathode slurry circulation is communicated with a slurry inlet of the cathode storage tank.

The positive electrode slurry circulation comprises a positive electrode slurry circulation pipeline and a first slurry pump for providing power for the slurry circulation, and the negative electrode slurry circulation comprises a negative electrode slurry circulation pipeline and a second slurry pump for providing power for the slurry circulation.

The electrolyte circulating system comprises at least one electrolyte storage tank and an electrolyte circulating pipeline, and the electrolyte circulating pipeline comprises at least one group of communicating pipelines;

wherein the communication duct comprises

A first communicating pipeline for communicating the electrolyte storage tank with the anode storage tank, a third communicating pipeline for communicating the electrolyte storage tank with the anode chamber, a fifth communicating pipeline for communicating the electrolyte storage tank with the first junction station, and/or

The second communicating pipeline is used for communicating the electrolyte storage tank with the negative electrode storage tank, the fourth communicating pipeline is used for communicating the electrolyte storage tank with the negative electrode cavity, and the sixth communicating pipeline is used for communicating the electrolyte storage tank with the second confluence device.

The electrolyte circulating system further comprises a pressure relief structure and an electrolyte stirring structure arranged in the electrolyte storage tank.

The electrolyte circulation system is characterized by further comprising a filtering structure for preventing active slurry from entering the electrolyte circulation system, wherein the filtering structure comprises a filter arranged at the joint of the electrolyte circulation pipeline and the positive storage tank, the negative storage tank, the first junction station, the second junction station and the electrochemical reaction structure.

Just, negative pole storage tank includes the storage tank body and locates the internal storage stirring structure of storage tank.

Still include the control valve structure, the control valve structure is including locating positive pole storage tank with first thick liquids control valve between the positive pole cavity, locate the negative pole storage tank with second thick liquids control valve between the negative pole cavity, locate the positive pole cavity with third thick liquids control valve between the first ware that converges and locating the negative pole cavity with fourth thick liquids control valve between the second ware that converges.

The energy storage active substance in the active slurry is granular solid, and the granular shape of the active slurry is one or a mixture of a plurality of spherical, cylindrical, irregular flaky and porous microsphere structures sintered by micro particles.

The electrochemical reaction structure comprises at least one dual-purpose electrochemical reactor that is both chargeable and dischargeable; or the electrochemical reaction structure comprises at least one group of electrochemical reactors specially used for charging and electrochemical reactors specially used for discharging.

A reference electrode is also included that monitors the real-time voltage of the active slurry within the electrochemical reaction structure.

Compared with the prior art, the invention has the following advantages:

in the invention, the active slurry comprises a deposition type active slurry form and a suspension type active slurry form, the deposition type active slurry form exists in the processes of storage and charging and discharging, and the deposition type active slurry form has higher stacking density, so that the deposition type active slurry form has better conductivity, higher energy density and better rate performance; when the slurry flows circularly, the slurry exists in a suspension type active slurry form, the deposition type active slurry discharged from the electrochemical reaction structure forms the suspension type active slurry by adding extra electrolyte, the flow resistance of the slurry in the circulating process is greatly reduced, and after the suspension type active slurry returns to the storage structure, the suspension type active slurry is automatically converted into the deposition type active slurry under the action of gravity, the deposition type active slurry is positioned at the bottom of the storage structure and directly enters the next circulation, so that the cyclic utilization of energy storage active substances is realized, the production cost is reduced, meanwhile, the separation of capacity and power is realized by the circular flow, and the energy density of the system is improved; the invention effectively solves the contradiction between the fluidity and the energy density in the concept of the lithium ion flow battery by the mutual conversion of the deposition type active slurry and the suspension type slurry, and simultaneously solves the key technical problem that the slurry is adhered to the diaphragm in the circulating pipeline and the reaction chamber; the invention can also be designed according to the energy storage active material materials and the electrolyte types of the active slurry required by different application scenes, and the equipment is easy to maintain.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic diagram of the overall structure of a slurry energy storage system according to the present invention;

FIG. 2 is a schematic flow diagram of the components of the active slurry output of the slurry energy storage system according to the present invention;

FIG. 3 is a schematic flow diagram of the components of the slurry energy storage system active slurry input according to the present invention;

FIG. 4 is a schematic view of the magazine structure according to embodiment 2;

description of reference numerals: 1-electrochemical reaction structure; 2-a positive storage tank; 3-a negative electrode storage tank; 4-an electrolyte circulation system; 5-a slurry circulation system; 6-positive electrode chamber; 7-a negative electrode chamber; 11-a slurry control valve; 12-a junction station; 13-a filter; 14-an electrolyte control valve; 15-a slurry circulation conduit; 16-an electrolyte circulation conduit; 17-a slurry pump; 18-an electrolyte reservoir; 19-an electrolyte stirring structure; 20-a pressure relief structure; 21-a storage structure; 22-storage stirring structure.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Example 1

As shown in fig. 1, the present embodiment provides a slurry energy storage system, which includes a storage structure 21, an electrochemical reaction structure 1, and a material circulation system, where the material circulation system includes an electrolyte circulation system 4 and a slurry circulation system 5; the material storage structure 21 is communicated with the electrochemical reaction structure 1, and the material circulation system is communicated with the material storage structure 21 and the electrochemical reaction structure 1; the during operation is located deposit type active slurry in the storage structure 21 is under driving power effect, by storage structure 21 gets into electrochemical reaction structure 1 reaction back, and discharge with electrolyte mixes and forms suspension type active slurry, and passes through slurry circulation system 5 returns storage structure 21 converts deposit type active slurry into again in the storage structure 21.

In the embodiment, the active slurry comprises a deposition type active slurry form and a suspension type active slurry form, and the deposition type active slurry form exists in the processes of storage, charging and discharging, and has higher bulk density, so that the reactor has better conductivity, higher energy density and better rate performance; when the slurry flows circularly, the slurry exists in a suspension type active slurry form, the deposition type active slurry discharged from the electrochemical reaction structure 1 forms the suspension type active slurry by adding extra electrolyte, so that the flow resistance of the slurry in the circulating process is greatly reduced, and after the suspension type active slurry returns to the storage structure 21, the suspension type active slurry is automatically converted into the deposition type active slurry under the action of gravity, the deposition type active slurry is positioned at the bottom of the storage structure 21 and directly enters the next circulation, so that the cyclic utilization of energy storage active substances is realized, the production cost is reduced, and meanwhile, the cyclic flow of the active slurry realizes the separation of capacity and power, and the energy density of the system is improved; the invention effectively solves the contradiction between the fluidity and the energy density in the concept of the lithium ion flow battery by the interconversion of the deposition type active slurry and the suspension type slurry, and simultaneously solves the key technical problem that the slurry is adhered to the membrane in the circulating pipeline and the reaction chamber; the invention can also be designed according to the energy storage active material materials and the electrolyte types of the active slurry required by different application scenes, and the equipment is easy to maintain.

In this embodiment, it is preferable that the storage structure 21 is disposed above the electrochemical reaction structure 1, and the descending driving force is self gravity or electrolyte pressure; since the active slurry enters the electrochemical reaction structure 1 is a sedimentation process, compared with the flow of solid particles in a liquid phase in the lithium ion battery in the prior art, the flow channel resistance can be greatly reduced, the flow channel resistance can be realized in a narrow flow channel, and the concentration polarization can be greatly reduced. Meanwhile, in the present embodiment, in the process of slowly discharging the deposition-type active slurry in the storage structure 21 downward, more electrolyte may slowly flow into the storage structure 21, and the storage structure 21 is always in a full state; for the electrochemical reaction structure 1, in the circulation process of the active slurry, the electrolyte can automatically scour the inner wall of the electrochemical reaction structure; therefore, the present embodiment solves the problem of the slurry adhering to the inner wall of the electrochemical reaction structure 1.

The embodiment further comprises a storage driving structure, which provides driving force for the deposition type active slurry in the storage structure 21 to enter the electrochemical reaction structure 1.

Further, the storage structure 21 comprises at least one group of storage components, the storage components comprise a positive storage tank 2 and a negative storage tank 3, and the positive storage tank 2 and/or the negative storage tank 3 are set as deposition type active slurry storage tanks; the slurry circulation system 5 comprises at least one set of slurry circulation components, and the slurry circulation components comprise positive slurry circulation and/or negative slurry circulation; when the positive electrode storage tank 2 is a deposition type active slurry storage tank and the slurry circulation assembly comprises a positive electrode slurry circulation, one end of the positive electrode slurry circulation is communicated with an outlet of a positive electrode chamber 6 of the electrochemical reaction structure 1 and the electrolyte circulation system 4 through a first junction station 12, and the other end of the positive electrode slurry circulation is communicated with a slurry inlet of the positive electrode storage tank 2; when the cathode storage tank 3 is a deposition-type active slurry storage tank and the slurry circulation assembly includes a cathode slurry circulation, one end of the cathode slurry circulation is communicated with the outlet of the cathode chamber 7 of the electrochemical reaction structure 1 and the electrolyte circulation system 4 through the second junction station 12, and the other end of the cathode slurry circulation is communicated with the slurry inlet of the cathode storage tank 3. In this embodiment, one of the positive storage tank 2 or the negative storage tank 3 can be selected to be a deposition-type slurry storage tank, and the other storage tank is selected to be a discharge tank in the prior art, so that the slurry circulation assembly only includes positive slurry circulation or negative slurry circulation; as a preferred embodiment, in the present embodiment, the positive electrode storage tank 2 and the negative electrode storage tank 3 are both configured as sedimentation type slurry storage tanks, and then the slurry circulation assembly includes a positive electrode slurry circulation and a negative electrode slurry circulation.

In the embodiment, the junction station 12 is an important place for converting the slurry from deposition type to suspension type, after the deposition type active slurry is discharged from the outlet of the electrochemical reaction structure 1, the deposition type active slurry is mixed with the electrolyte in the electrolyte circulation system 4 through the junction station 12 to form suspension type active slurry, and then the suspension type active slurry is returned to the storage structure 21 through the slurry circulation system 5, and the deposition type active slurry is formed again therein.

The anode slurry circulation comprises an anode slurry circulation pipeline 15 and a first slurry pump 17 for providing power for the slurry circulation, and the cathode slurry circulation comprises a cathode slurry circulation pipeline 15 and a second slurry pump 17 for providing power for the slurry circulation; the first slurry pump 17 and the second slurry pump 17 respectively provide power for the anode slurry circulation and the cathode slurry circulation, and the power of the first slurry pump 17 and the power of the second slurry pump 17 can be controlled to adjust and control the fluidization degree of the slurry in the anode slurry circulation pipeline 15 and the cathode slurry circulation pipeline 15 and the flowing speed of the suspension type active slurry; meanwhile, the whole slurry circulation system 5 is not in contact with the outside and is completely sealed. In the present embodiment, the first slurry pump 17 and the second slurry pump 17 are preferably submersible conveyance pumps.

Further, the electrolyte circulation system 4 comprises at least one electrolyte storage tank 18 and an electrolyte circulation pipeline 16, and the electrolyte circulation pipeline 16 comprises at least one group of communication pipelines;

the communicating pipe comprises

A first communication pipeline for communicating the electrolyte storage tank 18 with the positive electrode storage tank 2, a third communication pipeline for communicating the electrolyte storage tank 18 with the positive electrode chamber 6, a fifth communication pipeline for communicating the electrolyte storage tank 18 with the first junction station 12, and/or

A second communicating pipeline for communicating the electrolyte storage tank 18 with the negative electrode storage tank 3, a fourth communicating pipeline for communicating the electrolyte storage tank 18 with the negative electrode chamber 7, and a sixth communicating pipeline for communicating the electrolyte storage tank 18 with the second junction station 12.

When only the positive electrode storage tank 2 is a deposition type slurry storage tank and the slurry circulation assembly only comprises positive electrode slurry circulation, the communication pipeline only comprises a first communication pipeline, a third communication pipeline and a fifth communication pipeline; when only the negative electrode storage tank 3 is a deposition type slurry storage tank and the slurry circulation assembly only comprises negative electrode slurry circulation, the communication pipeline only comprises a second communication pipeline, a fourth communication pipeline and a sixth communication pipeline; as a preferable embodiment, in the present embodiment, the cathode storage tank 2 and the anode storage tank 3 are both configured as deposition type slurry storage tanks, and the slurry circulation assembly includes a cathode slurry circulation and an anode slurry circulation, so that the communication pipeline includes not only the first, third and fifth communication pipelines, but also the second, fourth and sixth communication pipelines. Meanwhile, in this embodiment, only one electrolyte storage tank may be preferably provided, and a plurality of electrolyte storage tanks may be provided in one-to-one correspondence to each of the positive and negative storage tanks.

In the embodiment, the existence of the electrolyte circulation system 4 enables the solid content of the active slurry in the junction station 12 to be reduced, and the pressure changes locally during the slurry circulation process, so that the internal pressure of the whole device is ensured to be stable through the electrolyte circulation.

The electrolyte circulating system 4 further comprises a pressure relief structure 20 and an electrolyte stirring structure 19 arranged in the electrolyte storage tank 18; the pressure relief structure 20 comprises a pressure relief valve arranged at the top end of the electrolyte storage tank 18, and when the hydraulic pressure in the slurry energy storage system is too high, the pressure can be relieved through the pressure relief structure 20 of the electrolyte circulation system 4; meanwhile, in the slurry energy storage system, the top end of the electrolyte storage tank 18 is the highest point, and when bubbles are generated in the reaction process, the bubbles can also be discharged through the pressure relief structure 20 of the electrolyte circulation system 4.

The embodiment further includes a filtering structure for preventing active slurry from entering the electrolyte circulation system 4, and the filtering structure includes a filter 13 disposed at a joint of the electrolyte circulation pipeline 16 and the positive storage tank 2, the negative storage tank 3, the first junction station 12, the second junction station 12, and the electrochemical reaction structure 1.

Just, negative pole storage tank 3 includes the storage tank body and locates storage stirring structure 22 in the storage tank body. In this embodiment, as a preferred embodiment, the storage tank body is made of steel-lined PE plastic, and the lower end of the storage tank body is set to be an inverted cone structure, so as to facilitate the sedimentation of the sedimentary active slurry; of course, as a changeable embodiment, the material storage tank body may be provided in other shapes, the capacity thereof may be designed according to actual use requirements, and the material storage tank body for the positive electrode and the material storage tank body for the negative electrode may have unified specifications or may be designed independently. Further, in the present embodiment, the storage stirring structure 22 may be configured as one or more of paddle type, open turbine type, propeller type, disc spiral type, frame type, anchor type, etc. stirrers, which may perform one or more stirring modes such as continuous stirring, intermittent stirring, etc.; in this embodiment, preferably, the energy storage stirring structure is a three-blade propeller type stirring device, and the stirring mode is slow stirring during the material changing cycle.

On the basis of the above embodiment, this embodiment further includes a control valve structure, the control valve structure includes a first slurry control valve 11 disposed between the positive electrode storage tank 2 and the positive electrode chamber 6, a second slurry control valve 11 disposed between the negative electrode storage tank 3 and the negative electrode chamber 7, a third slurry control valve 11 disposed between the positive electrode chamber 6 and the first flow combiner 12, and a fourth slurry control valve 11 disposed between the negative electrode chamber 7 and the second flow combiner 12. The control valve structure further comprises an electrolyte control valve 14 arranged between the electrolyte circulation system 4 and the junction station 12.

In the present embodiment, the flow rate of the deposition-type active slurry is controlled by the first slurry control valve 11 and the second slurry control valve 11, the flow rate of the deposition-type active slurry output from the positive electrode chamber 6 and the negative electrode chamber 7 is controlled by the third slurry control valve 11 and the fourth slurry control valve 11, and the electrolyte control valve 14 is used for controlling the flow rate of the electrolyte; the output deposition type active slurry enters the junction station 12, and meanwhile, the corresponding electrolyte flows into the junction station 12, so that the slurry flowing into the junction station 12 becomes suspension, the solid content is reduced, and the smooth transportation of the slurry is ensured; meanwhile, the deposition type active slurry entering the junction station 12 and the electrolyte entering the junction station 12 are fully mixed and smoothly flow under the action of the slurry pump 17 and the electrolyte stirring structure 19. Meanwhile, a corresponding circuit can be designed or a sensor can be added, and the opening size of each control valve can be adjusted through sensing or testing parameters such as pressure, flow velocity and density, so that the flow of each slurry can be controlled.

Specifically, the electrochemical reaction structure 1 includes at least one dual-purpose electrochemical reactor that is both chargeable and dischargeable; or the electrochemical reaction structure 1 includes at least one set of electrochemical reactors dedicated for charging and electrochemical reactors dedicated for discharging.

This embodiment also includes a reference electrode for monitoring the real-time voltage of the active slurry within the electrochemical reaction structure 1; as a preferred embodiment, the reference electrode is preferably arranged in the electrolyte circulation pipeline at the feed inlet of the negative storage tank; as an alternative embodiment, the reference electrode may be disposed in the slurry circulation system, in the electrolyte circulation line at the feed inlet of the positive reservoir, in the electrochemical reaction structure, or the like. Wherein the type of the reference electrode is determined according to the types of the active slurry and the electrolyte.

Further, in addition to the above embodiments, the energy storage active material in the active slurry in this embodiment is a granular solid, and the granular shape is one or a mixture of multiple kinds of spherical, cylindrical, irregular sheet, and porous microsphere structures sintered by fine particles. In the present embodiment, the active slurry exists in a suspension type state during circulation, and exists in a deposition type state both when stored in the bank structure 21 and when reacted in the electrochemical reaction structure 1; meanwhile, the granular energy storage active substances are settled in the reactor to form an electronic conductive network, so that the reaction can occur in the deposition type active slurry in the electrochemical reaction structure 1 during charging and discharging, and the charging and discharging rate characteristics can be greatly improved.

In this embodiment, the solid particles in the deposition-type active slurry are in a standing accumulation state, and the whole deposition-type active slurry is in a quicksand state; the suspension-type active slurry is in a suspension state of solid-liquid mixture, and the whole is in a flowing state. Specifically, the active material in this embodiment is set as energy storage particles, and the energy storage particles in the deposition type slurry are in stacked contact with each other; the energy storage particles in the deposition type slurry and the conductive agent cooperate to form a conductive network, so that the current is transmitted to the current collector through the conductive network and is led out from the positive electrode and the negative electrode to form an electronic loop; ion exchange occurs between the surface of the energy storage particles of the deposition type slurry and the electrolyte in the deposition type slurry, and ions migrate through the accumulation gaps between the energy storage particles of the deposition type slurry and penetrate through the diaphragm structure to form an ion loop.

In the present embodiment, the energy storage active material is a lithium ion battery material system; the anode material is one or a mixture of more of lithium iron phosphate, lithium manganese phosphate, lithium silicate, lithium iron silicate, sulfate compounds, titanium sulfide compounds, molybdenum sulfide compounds, iron sulfide compounds, doped lithium manganese oxides, lithium cobalt oxides, lithium titanium oxides, lithium vanadium oxides, lithium nickel manganese oxides, lithium nickel cobalt oxides, lithium nickel manganese cobalt oxides and other compounds capable of releasing and inserting lithium; the cathode material is one or a mixture of more of various carbon materials, reversible lithium-intercalation aluminum-based alloy, silicon-based alloy, tin-based alloy, lithium vanadium oxide and lithium titanium oxide; the electrolyte is a solution obtained by dissolving lithium hexafluorophosphate or lithium bis (oxalato) borate in an organic solvent or an ionic liquid; the organic solvent is one or more of dimethyl carbonate, diethyl carbonate, ethylene carbonate and propylene carbonate, the ionic liquid is one or more of N-methyl-N-propyl pyrrole-bis (trifluoromethyl sulfonyl) imine, 1-methyl-4-butyl pyridine-bis (trifluoromethyl sulfonyl) imine, 1, 2-dimethyl-3-N-butyl imidazole, 1-methyl-3-ethyl imidazole tetrafluoroboric acid and 1-methyl-3-butyl imidazole hexafluorophosphoric acid;

or the energy storage active material is set as a secondary zinc-manganese battery system; wherein, the anode is manganese dioxide and relative oxides of manganese, the cathode is metal zinc and zinc alloy, and the electrolyte is potassium hydroxide.

Or the energy storage active substance is a nickel-hydrogen battery system, wherein the positive electrode material is nickel oxyhydroxide, the negative electrode material is metal hydride, and the electrolyte is potassium hydroxide solution.

Or, the energy storage active substance is set as a ferroelectric battery electrode system, the positive electrode material can be nickel oxide, the negative electrode material can be metallic iron and iron alloy, and the electrolyte is potassium hydroxide solution containing lithium hydroxide.

Or the energy storage active material is set as a lead-acid battery material system; the positive electrode material is lead dioxide, the negative electrode material is metallic lead, and the electrolyte is a solution obtained by dissolving lead methylsulfonate in an organic solution or a sulfuric acid solution.

Or, the energy storage active substance is set as a zinc-nickel battery material system, for example, the positive electrode material is nickel dioxide, the negative electrode material is metal zinc and other metal zinc alloy, and the electrolyte is set as a soluble zincate alkaline solution or a soluble zincate acidic solution.

In the present embodiment, the states of the deposition-type active paste and the suspension-type active paste can also be described using the solid contents; however, when different active materials are used, the solid content limits of the deposition-type active slurry and the suspension-type active slurry are different, and in a lead-acid system, for example, in the charge state of the negative electrode slurry, the solid content of the deposition-type active slurry is greater than 80%, and the solid content of the suspension-type active slurry is lower than 80%.

The operation of this embodiment is as follows:

in an initial state, a deposition type active slurry is stored in the storage structure 21, and the electrochemical reaction structure 1, the electrolyte circulation system 4 and the slurry circulation system 5 are all filled with an electrolyte;

as shown in fig. 2, when the system starts to work, the first slurry control valve 11 and the second slurry control valve 11 are opened, the deposition type active slurry in the positive electrode storage tank 2 and the negative electrode storage tank 3 respectively sinks to the positive electrode chamber 6 and the negative electrode chamber 7 under the action of gravity and the pressure of the electrolyte, the electrolyte in the positive electrode chamber 6 and the negative electrode chamber 7 is discharged through the third communicating pipe and the fourth communicating pipe respectively, and enters the corresponding positive electrode storage tank 2 and the negative electrode storage tank 3 through the electrode liquid circulating system, and the deposition type active slurry in the positive electrode storage tank 2 and the negative electrode storage tank 3 is slowly and completely discharged;

the slurry entering the electrochemical reaction structure 1 is converted into deposition type active slurry again, and the positive electrode active slurry in the positive electrode cavity 6 and the negative electrode active slurry in the negative electrode cavity 7 carry out charge-discharge reaction in the electrochemical reaction structure 1;

as shown in fig. 3, after a certain charge-discharge reaction is completed, the third slurry control valve 11 and the fourth slurry control valve 11 are opened, the deposition-type positive active slurry and negative active slurry are discharged from the corresponding chambers and enter the corresponding confluence devices 12, and are mixed with the corresponding electrolytes to form suspension-type active slurry, and then the suspension-type active slurry is conveyed to the corresponding storage tanks through the corresponding slurry circulation systems 5, and the electrolytes in the storage tanks are circulated to the electrode solution storage tanks through the first communication pipes and the second communication pipes, respectively; then, the suspension type active slurry in the storage structure 21 is settled by standing, and the suspension type active slurry is converted into deposition type active slurry again, so that the cycle of deposition-suspension-deposition of the active slurry is completed.

In this embodiment, when the electrochemical reaction structure 1 is filled with the electrolyte, as long as the electrolyte stirring structure 19 continues to work, the electrolyte will flow in the electrochemical reaction structure 1, and the flow of the electrolyte will have a certain washing effect on the diaphragm wall or the side wall in the electrochemical reaction structure 1, so as to clean the diaphragm wall or the side wall of the electrochemical reaction structure 1.

When the slurry energy storage system is used in a small-scale intermittent working state, only one pair of positive and negative electrode storage tanks 3 and one or more pairs of electrochemical reaction structures 1 can be arranged; the design pipeline is simple in structure, and compared with the traditional lead-acid battery, the power and capacity separation is realized. Although the mixing of active slurries of different states of charge causes chemical reactions between the slurries that result in some loss of stored electrical energy, such losses are within acceptable limits when the device is scaled down.

When the slurry energy storage system is applied to a large-scale energy storage device and continuously works, two or more pairs of positive and negative storage tanks 3 can be adopted, wherein one half of the positive and negative storage tanks are used as full power storage tanks, and the other half of the positive and negative storage tanks are used as hunger power storage tanks; taking two pairs of storage tanks as an example, 2 positive electrode slurry storage tanks and 2 negative electrode storage tanks 3 are respectively used for storing positive and negative electrode active slurries of saturated power and hunger power, and the slurry storage in different charge states is realized by controlling feed inlet valves of the storage tanks, so that on one hand, the total residual electric quantity of the device can be judged by observing the quantity of the energy storage active substances in the positive electrode storage tanks or the negative electrode storage tanks, on the other hand, the slurry in different charge states is prevented from generating chemical reaction after being mixed, and the energy loss caused by the mixing of the slurries is reduced.

Example 2

On the basis of embodiment 1, the embodiment provides a slurry energy storage system with a designed installed capacity of 200kwh and a designed power of 60kw, the overall device height is about 2m, the occupied area is about 1.2m2, the device volume energy density is about 84wh/L, and the device volume energy density is basically consistent with that of a single valve-controlled lead-acid battery; the energy storage active substance of the system is replaceable, the energy storage active substance is updated once in two years on average, the design life is 30 years, the initial investment cost can be controlled to be about 70000 yuan through tests, and the cost of energy storage unit equipment and slurry is 350 yuan/kwh which is far lower than that of similar energy storage products in the current market.

The specific implementation mode is as follows:

the slurry energy storage system described in this embodiment includes 1 electrochemical reaction structure, 1,2 positive storage tanks, 2 negative storage tanks, 3, an electrolyte circulation system 4, and a slurry circulation system 5.

The anode storage tank 2 and the cathode storage tank 3 are located above the electrochemical reaction structure 1, and 4 storage tanks are arranged in a 2 × 2 manner, as shown in fig. 4; the diameter of the single anode storage tank 2 is set to be 0.46m, the height of the single anode storage tank is set to be 0.9m, the diameter of the discharge port is set to be 0.1m, the height of the inverted cone at the lower end of the single anode storage tank is 0.2m, and the capacity of the single anode storage tank is about 150L; the diameter of the negative electrode storage tank 3 is set to be 0.36m, the height is set to be 0.9m, the diameter of the discharge hole is set to be 0.1m, the height of the inverted cone of the discharge hole is 0.2m, and the capacity is about 90L; the electrolyte storage tank 18 is located in the center of the storage tank, and is a cylindrical tank with a diameter of 0.16m, a height of 1.4m, and a capacity of about 30L.

Meanwhile, the energy storage active material in the active slurry in the embodiment adopts a lead-acid battery system, wherein the energy storage active material particles are in a sphere-like shape, and the diameter of the energy storage active material particles is between 200 and 500 micrometers; the positive energy storage active material is lead dioxide particles, and 1560kg of the material is added; the negative energy storage active material is metal lead powder, and is charged with 1110kg in total, and the excess amount of the metal lead powder is about 30%; the electrolyte adopts a dilute sulfuric acid solution with the mass fraction of 40%, the density is about 1.3kg/L, and the electrolyte is filled in the whole device and is about 380L; meanwhile, 10kg and 23kg of activated carbon powder are respectively added into the positive electrode energy storage active material and the negative electrode energy storage active material to serve as conductive agents, wherein the particle size of the activated carbon is 25-100 micrometers.

As shown in fig. 4, the electrochemical reaction structure 1 includes a plurality of components, such as a positive electrode chamber 6, a negative electrode chamber 7, a separator, a positive electrode current collector, and a negative electrode current collector; in the embodiment, the electrochemical reaction structure 1 is a plate-type structure, and the electrochemical reaction structure 1 is divided into 33 positive electrode chambers 6 and 34 negative electrode chambers 7 by 66 groups of separation membranes, wherein the size of the chambers is 80cm × 80cm, and the distance between the chambers is about 5 mm; wherein the isolation membrane can be a non-woven fabric membrane, the surface of the isolation membrane is specially treated, the thickness of the isolation membrane is set to be 500 mu m, and the aperture of the isolation membrane is controlled to be less than 1 mu m; the positive current collector and the negative current collector are arranged in parallel in corresponding chambers, the thickness of the positive current collector and the negative current collector is 0.5mm, the size of a grid pore passage is 2mm multiplied by 2mm, the interval between adjacent monofilaments is 2 mm.

Further, all pipelines in the slurry circulating system 5 are plastic pipes with the diameter of 5cm, all slurry pumps 17 are submersible conveying pumps, and the power of the submersible conveying pumps is 3kw; meanwhile, all the pipelines in the electrolyte circulating system 4 are plastic pipes with the diameter of 3cm, and the electrolyte storage tank 18 is made of lining steel PE plastic.

Further, the positive electrode storage tank 3 and the negative electrode storage tank 3 are both designed into cylindrical tanks, the bottoms of the tanks are inverted cones, and the tanks are made of lining steel PE plastics; wherein, the storage stirring structure 22 is a three-blade propelling type stirring device, and the stirring working system is slow stirring during the material changing circulation.

The system works roughly as follows:

when the system does not work, the electrochemical reaction structure 1 is filled with electrolyte and does not contain energy storage active substances; the energy storage active material is stored in the positive electrode storage tank 3 and the negative electrode storage tank 3 respectively in the form of deposition type active slurry;

when the electrochemical reaction structure 1 starts to work, as shown in fig. 2, the first slurry control valve 11 and the second slurry control valve 11 are opened, the positive electrode active slurry and the negative electrode active slurry are uniformly deposited in the positive electrode cavity 7 and the negative electrode cavity 7 through the guide plate, the original electrolyte in the electrochemical reaction structure 1 is discharged through the first communicating pipeline and the second communicating pipeline at the upper ends respectively, and flows into the corresponding positive electrode storage tank 3 and the corresponding negative electrode storage tank 3 through the electrolyte circulating system 4, and the positive electrode storage tank 3 and the negative electrode storage tank 3 are emptied and start to be charged;

when the charging is finished, the energy storage active materials are replaced, as shown in fig. 3, the third slurry control valve 11 and the fourth slurry control valve 11 at the bottom of the electrochemical reaction structure 1 are completely opened, a slurry pump 17 in the slurry circulation system 5 reversely conveys slurry for 1s, the bottom deposition type active slurry in the positive and negative electrode chambers 7 is activated, the deposition type active slurry in the positive and negative electrode chambers 7 is discharged and enters the corresponding junction station 12, and the electrolyte stirring structure 19 in the electrolyte circulation system 4 works in the forward direction to join electrolyte into the junction station 12; wherein, the solid amount flowing into the confluence device 12 is reversely controlled by the third slurry control valve 11 and the fourth control, the liquid amount flowing into the confluence device 12 is controlled by the electrolyte control valve 14, so as to form suspension type active slurry under the mechanical stirring action of the slurry pump 17; in the process, the extra electrolyte required for converting the deposition type active slurry into the suspension type active slurry is provided by the electrolyte in the electrolyte circulation system 4;

in the process that the deposition type active slurry flows out of the electrochemical reaction structure 1, the hydraulic pressure of the electrochemical reaction structure 1 is reduced, and at the moment, new electrolyte is injected from a third communicating pipeline and a fourth communicating pipeline in the electrolyte circulating system 4 for buffering;

after the sedimentary active slurry is converted into the suspension active slurry, the suspended active slurry is conveyed to the corresponding anode storage tank 3 and the corresponding cathode storage tank 3 through the slurry circulating system 5, the slurry in the storage tanks is sedimentated under the action of gravity and is accumulated at the bottom of the storage tanks, and the sedimentary active slurry is formed again, so that a cycle is completed.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims

1. Slurry energy storage system, its characterized in that: the electrochemical reaction device comprises a storage structure (21), an electrochemical reaction structure (1) and a material circulating system, wherein the material circulating system comprises an electrolyte circulating system (4) and a slurry circulating system (5); the material storage structure (21) is communicated with the electrochemical reaction structure (1), and the material circulating system is communicated with the material storage structure (21) and the electrochemical reaction structure (1); the during operation is located sedimentary type active slurry in storage structure (21) is under driving power effect, by storage structure (21) gets into electrochemical reaction structure (1) reaction back, and discharge with electrolyte mixes and forms suspension type active slurry, and passes through slurry circulation system (5) return storage structure (21) convert sedimentary type active slurry again in storage structure (21).

2. The slurry energy storage system of claim 1, wherein: the storage structure (21) comprises at least one group of storage components, each storage component comprises a positive storage tank (2) and a negative storage tank (3), and the positive storage tanks (2) and/or the negative storage tanks (3) are set as deposition type active slurry storage tanks; the slurry circulation system (5) comprises at least one set of slurry circulation components comprising positive slurry circulation and/or negative slurry circulation; when the positive electrode storage tank (2) is set as a deposition type active slurry storage tank and the slurry circulation assembly comprises a positive electrode slurry circulation, one end of the positive electrode slurry circulation is communicated with an outlet of a positive electrode cavity (6) of the electrochemical reaction structure (1) and the electrolyte circulation system (4) through a first junction station (12), and the other end of the positive electrode slurry circulation is communicated with a slurry inlet of the positive electrode storage tank (2); when the cathode storage tank (3) is set to be a deposition type active slurry storage tank and the slurry circulation component comprises a cathode slurry circulation component, one end of the cathode slurry circulation component is communicated with an outlet of a cathode cavity (7) of the electrochemical reaction structure (1) and the electrolyte circulation system (4) through a second confluence device (12), and the other end of the cathode slurry circulation component is communicated with a slurry inlet of the cathode storage tank (3).

3. The slurry energy storage system of claim 2, wherein: the positive electrode slurry circulation comprises a positive electrode slurry circulation pipeline (15) and a first slurry pump (17) for providing power for the slurry circulation, and the negative electrode slurry circulation comprises a negative electrode slurry circulation pipeline (15) and a second slurry pump (17) for providing power for the slurry circulation.

4. The slurry energy storage system of claim 2, wherein: the electrolyte circulating system (4) comprises at least one electrolyte storage tank (18) and an electrolyte circulating pipeline (16), and the electrolyte circulating pipeline (16) comprises at least one group of communicating pipelines; the communicating pipeline comprises a first communicating pipeline for communicating the electrolyte storage tank (18) with the positive electrode storage tank (2), a third communicating pipeline for communicating the electrolyte storage tank (18) with the positive electrode chamber (6), a fifth communicating pipeline for communicating the electrolyte storage tank (18) with the first junction station (12), and/or a second communicating pipeline for communicating the electrolyte storage tank (18) with the negative electrode storage tank (3), a fourth communicating pipeline for communicating the electrolyte storage tank (18) with the negative electrode chamber (7), and a sixth communicating pipeline for communicating the electrolyte storage tank (18) with the second junction station (12).

5. The slurry energy storage system of claim 4, wherein: electrolyte circulation system (4) still include pressure release structure (20) and locate electrolyte stirring structure (19) in electrolyte storage tank (18).

6. The slurry energy storage system of claim 4, wherein: the electrolyte circulation system is characterized by further comprising a filtering structure for preventing active slurry from entering the electrolyte circulation system (4), wherein the filtering structure comprises a filter (13) arranged at the joint of the electrolyte circulation pipeline (16) and the anode storage tank (2), the cathode storage tank (3), the first junction station (12), the second junction station (12) and the electrochemical reaction structure (1).

7. The slurry energy storage system of claim 5, wherein: still include the control valve structure, the control valve structure including locate anodal storage tank (2) with first thick liquids control valve (11) between anodal cavity (6), locate negative pole storage tank (3) with second thick liquids control valve (11) between negative pole cavity (7), locate anodal cavity (6) with third thick liquids control valve (11) between first converging ware (12) and locate negative pole cavity (7) with fourth thick liquids control valve (11) between second converging ware (12).

8. The slurry energy storage system of claim 1, wherein: the energy storage active substance in the active slurry is a granular solid, and the granular shape of the active slurry is one or a mixture of a plurality of spherical, cylindrical, irregular flaky and porous microsphere structures sintered by micro particles.

9. The slurry energy storage system of claim 1, wherein: said electrochemical reaction structure (1) comprises at least one dual-purpose electrochemical reactor that is both chargeable and dischargeable; or the electrochemical reaction structure (1) comprises at least one set of electrochemical reactors dedicated to charging and electrochemical reactors dedicated to discharging.

10. The slurry energy storage system according to any of claims 1-9, wherein: and a reference electrode for monitoring the real-time voltage of the active slurry in the electrochemical reaction structure (1).