Zinc-bromine flow battery system

Abstract

The utility model discloses a zinc-bromine flow battery system and relates to the technical field of zinc-bromine flow batteries. The zinc-bromine flow battery system comprises a positive electrolyte storage tank, a negative electrolyte storage tank, delivery pumps and an electric pile, and the two electrolyte storage tanks are respectively connected with the electric pile through the delivery pumps; an electrolyte inlet and two electrolyte outlets are formed in the positive electrode electrolyte storage tank, one electrolyte outlet is located in a supernatant layer, the other electrolyte outlet is located in a bromine deposition lower layer, the two electrolyte outlets are connected to a liquid mixer in parallel through pipelines, and an outlet of the liquid mixer is connected with a delivery pump. According to the utility model, the electrolyte outlet is additionally arranged on the positive electrolyte storage tank, the two electrolyte outlets are respectively arranged on the supernatant layer and the lower bromine deposition layer, the outlet pipelines connected with the two electrolyte outlets are both connected to the liquid mixer, the bromine deposition phase and the supernatant in the positive electrolyte are uniformly mixed by the liquid mixer, and then the mixture is fed into the galvanic pile; and the energy efficiency of the battery is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to zinc bromine flow battery technical field especially relates to a kind of zinc bromine flow battery system. BACKGROUND

[0002] The positive and negative electrolyte of zinc bromine flow battery are ZnBr2 aqueous solution, and the electrolyte is circulated through the surface of positive and negative electrode by pump. When charging, zinc is deposited on the negative electrode, and the bromine generated at the positive electrode will be immediately complexed into oil-like substances by bromine complexing agent in the electrolyte, greatly reducing the bromine content in the aqueous phase, and the density of the substance is greater than that of the electrolyte, which will gradually deposit at the bottom of the storage tank during liquid circulation. After several charge and discharge cycles, the positive electrolyte storage tank will have a layered oil phase and aqueous phase, and the electrolyte inlet and outlet of the ordinary electrolyte storage tank are both one, so that the liquid concentration is not uniform when the positive electrolyte is output, thereby reducing the battery efficiency of zinc bromine flow battery. SUMMARY

[0003] The utility model provides a kind of zinc bromine flow battery system, solve the problem of two-phase mixed unevenly of positive electrolyte.

[0004] To achieve this technical purpose, the utility model adopts the following scheme: a zinc bromine flow battery system includes positive and negative electrolyte storage tanks, a delivery pump and a stack, two electrolyte storage tanks are connected with the stack by the delivery pump;The positive electrolyte storage tank is provided with an electrolyte inlet and two electrolyte outlets, one of which is located in the supernatant layer, and the other is located in the bromine deposition lower layer, and the two electrolyte outlets are connected to a liquid mixer through a pipeline in parallel, and the outlet of the liquid mixer is connected with the delivery pump.

[0005] Compared with the prior art, the utility model has the advantages that: the utility model increases an electrolyte outlet on the positive electrolyte storage tank, and the two electrolyte outlets are arranged in the supernatant layer and the lower bromine deposition layer, respectively, and the outlet pipes connected to the two electrolyte outlets are connected to the liquid mixer, which mixes the bromine deposition phase and the supernatant in the positive electrolyte evenly, and then feeds into the stack, thereby increasing the energy efficiency of the battery.

[0006] Preferably, the negative electrolyte storage tank is provided with an electrolyte inlet and an electrolyte outlet.

[0007] Preferably, it further includes a bidirectional converter and a user end, and the stack is connected with the user end through the bidirectional converter.

[0008] Preferably, it further includes an external power supply, which is connected with the delivery pump to provide electric energy for the delivery pump;When the stack is charging, the external power supply provides electric energy for the delivery pump to make the electrolyte run normally.

[0009] Preferably, the external power supply is also connected to a bidirectional converter, and the fuel cell stack charges the external power supply. When the fuel cell stack discharges, a portion of the electricity is delivered to the user end, and the other portion is used to charge the external power supply, realizing the self-circulation of the fuel cell stack, ensuring the stability of the battery, improving the cycle life of the fuel cell stack energy storage module, and making the system operation simpler. Attached Figure Description

[0010] Figure 1 A connection diagram of the zinc-bromine redox flow battery system provided in this embodiment of the present invention;

[0011] Figure 2 This is a schematic diagram of the structure of the positive electrode electrolyte storage tank provided in an embodiment of the present invention;

[0012] The following are marked in the diagram: 1. Positive electrolyte storage tank; 11. Positive electrolyte outlet; 12. Manhole; 13. Vent; 14. Level gauge; 15. Positive electrolyte inlet; 2. Positive transfer pump; 3. Negative electrolyte storage tank; 4. Negative transfer pump; 5. Fuel cell stack; 6. Mixer; 7. External power supply; 8. Bidirectional converter; 9. User terminal. Detailed Implementation

[0013] To fully understand the purpose, features and effects of this utility model, the following specific embodiments will be used to describe this utility model in detail, but this utility model is not limited thereto.

[0014] like Figure 1 As shown, this utility model provides a zinc-bromine flow battery system, including a positive electrolyte storage tank 1, a negative electrolyte storage tank 3, a positive electrode transfer pump 2, a negative electrode transfer pump 4, and a battery stack 5. The negative electrolyte storage tank 3 has an electrolyte outlet and an electrolyte inlet. The electrolyte outlet of the negative electrolyte storage tank 3 is connected to the negative electrode transfer pump 4 via a pipe. The negative electrode transfer pump 4 is connected to the negative electrode inlet of the battery stack 5 via a pipe. The negative electrode outlet of the battery stack 5 is connected to the electrolyte inlet of the negative electrolyte storage tank 3 via a pipe. The positive electrolyte storage tank 1 has a positive electrolyte inlet 15 and two positive electrolyte outlets 11. One positive electrolyte outlet 11 is located in the upper clear liquid layer of the positive electrolyte storage tank 1, and the other positive electrolyte outlet 11 is located in the lower bromine deposition layer of the positive electrolyte storage tank 1. Figure 2 As shown, both positive electrolyte outlets 11 are connected to branch pipes, which are connected in parallel to the mixer 6. The mixer 6 is used to mix the clear electrolyte and the bromine-deposited portion of the positive electrolyte evenly. The mixer 6 is then connected to the positive electrode transfer pump 2 through a pipe. The positive electrode transfer pump 2 is connected to the positive electrode inlet of the fuel cell stack 5. The positive electrode outlet of the fuel cell stack 5 is connected to the positive electrolyte inlet 15 of the positive electrolyte storage tank 1 through a pipe. The mixer 6 can be a static pipeline mixer, a venturi mixer, or other liquid mixer capable of liquid mixing.

[0015] Preferably, the positive and negative electrolyte storage tanks are each provided with a manhole 12, an exhaust hole 13 and a liquid level gauge 14 at the top.

[0016] In some preferred embodiments, a bidirectional converter 8, an external power source 7 and a user end 9 are further included, the electric pile 5 is connected with the bidirectional converter 8, the bidirectional converter 8 is connected with the user end 9 and the external power source 7 respectively, and the external power source 7 is electrically connected with the positive and negative delivery pumps respectively.

[0017] Working process:

[0018] When the electric pile 5 is charging, the external power source 7 provides electric energy for the positive and negative delivery pumps to circulate the electrolyte, the electrolyte in the positive electrolyte storage tank 1 is divided into supernatant and bromine deposition and then enters the mixing device 6 to be mixed, the mixed positive electrolyte is delivered to the electric pile 5 to generate electrode reaction, and the reacted liquid is delivered back to the positive electrolyte storage tank 1; the negative electrolyte also generates electrode reaction in the electric pile 5 and then circulates.

[0019] When the electric pile 5 is discharging, the electric energy provided by the electric pile 5 is partly delivered to the user end 9 through the bidirectional converter 8 and the other part is delivered to the external power source 7 to charge, and the external power source 7 provides power for the delivery pump.

[0020] Finally, it should be noted that: the above-mentioned is only the preferred embodiment of the present application, of course, the person skilled in the art can modify and change the present application, provided that these modifications and changes are within the scope of the present application claim and its equivalent technology, all should be considered as the protection scope of the present application.

Claims

1. A zinc-bromine flow battery system comprising positive and negative electrolyte reservoirs, a delivery pump and an electrical stack, the two electrolyte reservoirs being connected to the electrical stack by the delivery pump; characterised in that, The positive electrolyte storage tank is provided with an electrolyte inlet and two electrolyte outlets, one of which is located in the supernatant layer, and the other is located in the bromine deposition lower layer, and the two electrolyte outlets are connected in parallel to the mixing device through pipelines, and the outlet of the mixing device is connected with the delivery pump.

2. The zinc-bromine flow battery system of claim 1, wherein, The negative electrolyte storage tank is provided with an electrolyte inlet and an electrolyte outlet.

3. The zinc-bromine flow battery system of claim 1, wherein, The top of the positive and negative electrolyte storage tanks is provided with a manhole for maintenance.

4. The zinc-bromine flow battery system of claim 1, wherein, The positive and negative electrolyte storage tanks are both provided with liquid level meters.

5. The zinc-bromine flow battery system of claim 1, wherein, It also includes a bidirectional converter and a user end, and the stack is connected with the user end through the bidirectional converter.

6. The zinc-bromine flow battery system of claim 5, wherein, It also includes an external power supply, which is connected with the delivery pump to provide power for the delivery pump.

7. The zinc-bromine flow battery system of claim 6, wherein, The external power supply is also connected with the bidirectional converter, and the stack charges the external power supply.

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