Sodium salt battery formation process

Abstract

The invention relates to a sodium salt battery chemical process which comprises the following steps: S1, building a test circuit, S2, heating a sodium salt battery pack to 325 DEG C, and maintaining the temperature for 3 hours; s3, performing operation according to certain parameters; the sodium salt battery pack is cooled to be lower than 80 DEG C, the voltage of each battery cell is measured, and the voltage of each battery cell ranges from 2.3 V to 2.4 V; according to the chemical process of the sodium salt battery, a circuit can be built automatically, BMS equipment does not need to be specially developed to carry out a formation process, and the development cost and the development period can be greatly saved.

Description

Technical Field

[0001] The invention belongs to the technical field of sodium salt batteries and relates to a sodium salt battery formation process. Background Art

[0002] During the manufacturing process of sodium salt batteries, a formation process must be carried out to activate the battery. The formation process is a very important link in the manufacturing process of sodium salt batteries. The quality of the formation process directly determines the performance of sodium salt batteries. The formation process is also a process with high energy consumption.

[0003] Currently, there are few sodium salt battery pack models on the market. The more common battery model is E4815. The battery cell combination is 6 in parallel and 21 in series, totaling 126 cells. The formation process is that 126 sodium salt batteries are formed at the same time, and the maximum number of series connections is 21. The simultaneous formation requires the configuration of a specially developed BMS to assist the formation process, which will increase the development cost and development cycle, high production cost and low production efficiency. Summary of the invention

[0004] The purpose of the present invention is to solve the above problems and provide a sodium salt battery formation process.

[0005] To achieve the above object, the present invention provides a sodium salt battery formation process, comprising:

[0006] S1. Build the test circuit.

[0007] S2, heating the sodium salt battery pack to 325°C and maintaining for 3 hours;

[0008] S3. Operate according to the parameters in the following table:

[0009]

[0010]

[0011] Among them, C represents capacity; t represents the working step time; T represents temperature; U represents total pressure; I represents total current;

[0012] S4. Cool the sodium salt battery pack to less than 80°C and measure the voltage of each cell. The cell voltage is between 2.3-2.4V.

[0013] If any of the steps are not met, remove the damaged battery cell, replace the battery cell and repeat the above steps for testing.

[0014] Further, in step S1:

[0015] A first temperature controller and a second temperature controller are respectively connected to a first thermocouple and a second thermocouple in the sodium salt battery pack, and the first temperature controller and the second temperature controller are both connected to a first power supply;

[0016] The first temperature controller is connected to a first solid-state relay, the second temperature controller is connected to a second solid-state relay, two ends of the heating plate in the sodium salt battery pack are connected to the first solid-state relay and the second solid-state relay respectively, and the first solid-state relay and the second solid-state relay are connected to the positive electrode and the negative electrode of the second power supply respectively;

[0017] The second temperature controller is connected to a third solid-state relay, and the 300 sodium salt cells in the sodium salt battery pack are connected in series, connecting the third solid-state relay and the charging and discharging unit.

[0018] Further, the voltage between the battery cells B1 and B100 is V1, the voltage between the battery cells B100 and B200 is V2, and the voltage between the battery cells B200 and B300 is V3;

[0019] In step S3, in sequence number 3-7, the voltage difference between V1, V2, and V3 is less than 2V, otherwise it is necessary to stop and check the battery status.

[0020] Furthermore, in step S3, the battery capacity discharged by the charging and discharging unit in sequence number 5-7 is not less than 40Ah.

[0021] Further, in step S3, when sequence number 6 ends, the total voltage range is between 765V and 771V.

[0022] The beneficial effects of the present invention are as follows:

[0023] The sodium salt battery chemical process of the present invention can build its own circuit and does not require special development of BMS equipment for chemical formation process, which can greatly save development costs and development cycles. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The circuit principle diagram of the sodium salt formation process according to one embodiment of the present invention is schematically shown. DETAILED DESCRIPTION

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments cannot be described one by one here, but the embodiments of the present invention are not therefore limited to the following embodiments.

[0027] Combination Figure 1As shown, the present invention provides a sodium salt battery formation process, including a sodium salt battery formation process, including: S1, building a test circuit, S2, heating the sodium salt battery pack to 325° C. and maintaining it for 3 hours; S3, installing certain parameters for charge and discharge operations.

[0028] Specifically, in step S1, a first temperature controller 1 and a second temperature controller 2 are respectively connected to the first thermocouple 3 and the second thermocouple 4 in the sodium salt battery pack, and the first temperature controller 1 and the second temperature controller 2 are both connected to the first power supply 5 for power supply; the first temperature controller 1 is connected to the first solid-state relay 6, and the second temperature controller 2 is connected to the second solid-state relay 7. Both ends of the heating plate 8 in the sodium salt battery pack are respectively connected to the first solid-state relay 6 and the second solid-state relay 7, and the first solid-state relay 6 and the second solid-state relay 7 are respectively connected to the positive and negative electrodes of the second power supply 9; the second temperature controller 2 is connected to the third solid-state relay 10, and 300 sodium salt cells in the sodium salt battery pack are connected in series, connecting the third solid-state relay 10 and the charging and discharging unit 11.

[0029] The environmental conditions for sodium salt battery cells are 295℃~350℃. First of all, the temperature inside the battery pack must be guaranteed. The circuit design is as follows Figure 1 As shown, the first power supply 5 provides power to the two temperature controllers, which can be 12VDC or 220VAC; the first temperature controller 1 sets the parameter to close the first solid-state relay 6 at a temperature of less than 325°C, because the formation effect is better in an environment with a temperature as high as possible, and the formation and discharge process is an exothermic process, and the temperature inside the battery pack will rise, so 325°C is a suitable temperature;

[0030] The second temperature controller 2 is set to disconnect the second solid-state relay 7 and the third solid-state relay 10 when the temperature is greater than 350°C. When the temperature of the sodium salt battery exceeds 350°C, the aging speed of the glass layer of the battery cell is accelerated, and it is not suitable to exceed 350°C. The two relays are designed to be linked. When the heating circuit (the circuit connected to the heating plate 8) fails, the battery charging and discharging circuit (the circuit connected to the battery cell) also stops;

[0031] When the first solid-state relay 6 and the second solid-state relay 7 are closed, the heating circuit is in a closed state. The second power supply 9 is determined according to the design of the heating plate. Generally, a 48VDC heating plate is used, the heating power is about 1200W, the circuit current is about 25A, and a 4mm2 DC cable can be used. At the same time, an insurance is provided to prevent serious situations caused by a failure of the heating plate. The double relay design of the heating circuit further ensures the circuit reliability to prevent accidents.

[0032] The charge and discharge circuit is composed of 300 sodium salt cells connected in series, a third relay 10, and a charge and discharge motor 11. The charge and discharge motor 11 is currently the mainstream application in the industry and has functions such as reverse connection protection and alarm power-off. Therefore, this circuit does not require too many safety settings.

[0033] The voltage between cells B1- and B100+ is V1, the voltage between B100+ and B200+ is V2, and the voltage between B200+ and B300+ is V3. V1, V2, and V3 are collected by the charging and discharging cabinet as input conditions for battery fault alarm.

[0034] The sodium salt battery formation process of the present invention is to heat the battery pack to 325°C after the above circuit is built, and maintain the temperature for at least 3 hours. Then operate according to the parameters in the following table:

[0035]

[0036] Among them, C represents capacity; t represents the working step time; T represents temperature; U represents total pressure; I represents total current;

[0037] Among them, in step S3, in sequence numbers 3-7, the voltage difference between V1, V2, and V3 is less than 2V, otherwise it is necessary to stop and check the battery status. In step S3, the battery capacity discharged by the charging and discharging unit 11 in sequence numbers 5-7 is not less than 40Ah. In step S3, when sequence number 6 ends, its total voltage range is between 765-771V.

[0038] Afterwards, the sodium salt battery pack was cooled to less than 80°C and the voltage of each cell was measured, which was between 2.3-2.4V.

[0039] Carry out the formation process according to the above method. If any step is not met, remove the damaged battery cell, replace the battery cell and repeat the above steps for testing.

[0040] The sodium salt battery chemical process of the present invention can build its own circuit and does not require special development of BMS equipment for the formation process, which can greatly save development costs and development cycles; the present invention also greatly increases the number of formations, which can improve production efficiency and reduce production costs; in addition, the formation process conforms to the characteristics of the battery cell and will have better cycle performance.

[0041] The above is only one embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A sodium salt battery formation process, comprising: S1. Build the test circuit. S2, heating the sodium salt battery pack to 325°C and maintaining for 3 hours; S3. Operate according to the parameters in the following table: Among them, C represents capacity; t represents the working step time; T represents temperature; U represents total pressure; I represents total current; S4. Cool the sodium salt battery pack to less than 80°C and measure the voltage of each cell. The cell voltage is between 2.3-2.4V. If any of the steps are not met, remove the damaged battery cell, replace the battery cell and repeat the above steps for testing.

2. The sodium salt battery formation process according to claim 1, characterized in that: In step S1: A first temperature controller (1) and a second temperature controller (2) are respectively connected to a first thermocouple (3) and a second thermocouple (4) in the sodium salt battery pack, and the first temperature controller (1) and the second temperature controller (2) are both connected to a first power supply (5) for power supply; The first temperature controller (1) is connected to a first solid-state relay (6), the second temperature controller (2) is connected to a second solid-state relay (7), two ends of a heating plate (8) in a sodium salt battery pack are respectively connected to the first solid-state relay (6) and the second solid-state relay (7), and the first solid-state relay (6) and the second solid-state relay (7) are respectively connected to a positive electrode and a negative electrode of a second power source (9); The second temperature controller (2) is connected to a third solid-state relay (10), and the 300 sodium salt cells in the sodium salt battery pack are connected in series, connecting the third solid-state relay (10) and the charging and discharging unit (11).

3. The sodium salt battery formation process according to claim 2, characterized in that: The voltage between the battery cells B1 and B100 is V1, the voltage between the battery cells B100 and B200 is V2, and the voltage between the battery cells B200 and B300 is V3; In step S3, in sequence number 3-7, the voltage difference between V1, V2, and V3 is less than 2V, otherwise it is necessary to stop and check the battery status.

4. The sodium salt battery formation process according to claim 3, characterized in that: In step S3, the battery capacity discharged by the charging and discharging unit (11) in sequence number 5-7 is not less than 40Ah.

5. The sodium salt formation process according to claim 4, characterized in that: In step S3, when sequence number 6 ends, the total voltage range is between 765V and 771V.

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