Lithium supplementing device for negative pole piece of lithium ion battery

Abstract

The utility model relates to a lithium supplementing device for a negative pole piece of a lithium ion battery. The lithium supplementing device comprises a metal container, a reel, a cylinder, a metal lithium piece, a diaphragm, the negative pole piece, a metal cover plate, a resistor and a switch, two reels are arranged above the metal container, a cylinder is fixedly arranged on the side wall of the metal container, electrolyte is filled in the metal container, and a metal lithium piece, a diaphragm, a negative pole piece and a metal cover plate are sequentially arranged in the metal container from bottom to top; the negative pole piece is located below the cylinder, the two ends of the negative pole piece are connected with the reel, and the electrolyte submerges the negative pole piece; one end of the wire is connected with the metal cover plate, and the other end of the wire is connected with the bottom of the metal container. By adopting the device to supplement lithium, the lithium supplement efficiency can be improved, the SEI film can grow uniformly and stably, and the first efficiency and the capacity of the battery are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium ion batteries, and in particular to a lithium replenishing device for a negative electrode plate of a lithium ion battery. Background Art

[0002] With the aggravation of environmental pollution and the consumption of fossil energy, people are more and more eager to develop and utilize clean energy (such as wind power, photovoltaics, etc.). As a method of energy storage, lithium-ion batteries have the advantages of high open circuit voltage, high energy density and no pollution, and have been widely used in electronics, electric vehicles and other fields.

[0003] However, during the first charge and discharge process of the battery, the electrolyte will undergo reductive decomposition on the surface of the positive and negative active materials to form a layer of "solid electrolyte interface film" (also known as SEI film). The existence of the SEI film can avoid direct contact between the electrolyte and the active materials, greatly improving the cycle performance and service life of the electrode. However, the formation of the SEI film will also irreversibly consume a certain amount of lithium ions, reducing the coulombic efficiency of the first charge and discharge.

[0004] At present, researchers have proposed a method of pre-replenishing lithium to the negative electrode to improve the initial efficiency and capacity of the battery. However, some existing lithium replenishment processes are accompanied by high-temperature reactions, increasing the risk of fire and explosion, and some have problems such as uneven and unstable growth of the SEI film during the lithium replenishment process. In addition, the operating efficiency of existing lithium replenishment methods is also low. Summary of the invention

[0005] The utility model provides a lithium replenishing device for the negative electrode plate of a lithium ion battery. The lithium replenishing device is used to replenish lithium, which can improve the lithium replenishing efficiency and also make the SEI film grow evenly and stably, effectively improving the initial efficiency and capacity of the battery.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A lithium replenishing device for negative electrode sheets of lithium ion batteries comprises a metal container, a reel, a cylinder, a metal lithium sheet, a diaphragm, a negative electrode sheet, a metal cover plate, a resistor and a switch; two reels are arranged above the metal container, the cylinder is fixedly arranged on the side wall of the metal container, the metal container is filled with electrolyte, and the metal lithium sheet, the diaphragm, the negative electrode sheet and the metal cover plate are arranged in sequence from bottom to top in the metal container; the negative electrode sheet is located below the cylinder, the two ends of the negative electrode sheet are connected to the reel, and the electrolyte covers the negative electrode sheet; one end of the wire is connected to the metal cover plate, and the other end is connected to the bottom of the metal container, and the resistor and the switch are connected to the wire.

[0008] The edge of the metal lithium sheet is 5 to 10 mm smaller than the diaphragm.

[0009] The cylinder is a roller shaft.

[0010] The number of the cylinders is two or more.

[0011] A lithium replenishing device for a negative electrode plate of a lithium ion battery also includes an ultrasonic rod and an ultrasonic generator; the ultrasonic rod is arranged in a metal container, and the ultrasonic rod is connected to the ultrasonic generator.

[0012] The ultrasonic rod is fixedly connected to the metal container via a fixing ring.

[0013] A lithium replenishing device for a negative electrode plate of a lithium ion battery also includes a thermometer; the thermometer is arranged in a metal container.

[0014] Compared with the prior art, the beneficial effects of the utility model are:

[0015] The utility model provides a lithium replenishing device in which the negative electrode plate can be fully immersed in the electrolyte, the negative electrode plate and the electrolyte are in "face-to-face" contact, the contact between the negative electrode plate and the electrolyte is uniform, and the reaction between the negative electrode plate and the electrolyte is also uniform, which is also conducive to the formation of a uniform SEI film; in addition, the negative electrode plate can be replenished with lithium section by section, the negative electrode plate after lithium replenishment is wound on a reel, and the negative electrode plate that has not been replenished with lithium is released into the electrolyte for lithium replenishment, and lithium replenishment is continuously performed in this cyclic operation, with high working efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the accompanying drawings:

[0017] Figure 1 It is a structural schematic diagram of a lithium replenishing device for a negative electrode plate of a lithium-ion battery described in the utility model.

[0018] Description of reference numerals:

[0019] In the figure: 1. Metal container 2. Scroll 3. Cylinder 4. Metal lithium sheet 5. Diaphragm 6. Negative electrode sheet 7. Metal cover 8. Resistor 9. Switch 10. Electrolyte 11. Ultrasonic rod 12. Ultrasonic generator 13. Thermometer 14. Fixed ring DETAILED DESCRIPTION

[0020] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0021] The specific implementation of the utility model is further described below in conjunction with the accompanying drawings:

[0022] like Figure 1As shown, a lithium-ion battery negative electrode sheet lithium replenishing device includes a metal container 1, a reel 2, a cylinder 3, a metal lithium sheet 4, a diaphragm 5, a negative electrode sheet 6, a metal cover plate 7, a resistor 8 and a switch 9. Two reels 2 are arranged above the metal container 1, and the cylinder 3 is fixedly arranged on the side wall of the metal container 1. The metal container 1 is filled with an electrolyte 10. The metal lithium sheet 4, the diaphragm 5, the negative electrode sheet 6 and the metal cover plate 7 are arranged in sequence from bottom to top in the metal container 1. The negative electrode sheet 6 is located below the cylinder 3, and both ends of the negative electrode sheet 6 are connected to the reel 2, and the electrolyte 10 covers the negative electrode sheet 6. One end of the wire is connected to the metal cover plate 7, and the other end is connected to the bottom of the metal container 1, and the resistor 8 and the switch 9 are connected to the wire. The edge of the metal lithium sheet 7 is 5 to 10 mm smaller than the diaphragm.

[0023] The cylinder 3 can also be configured as a roller. The number of cylinders 3 is two or more.

[0024] A lithium-ion battery negative electrode plate lithium replenishing device also includes an ultrasonic rod 11 and an ultrasonic generator 12. The ultrasonic rod 11 is arranged in a metal container 1, and the ultrasonic rod 11 is connected to the ultrasonic generator 12. The ultrasonic rod 11 is fixedly connected to the metal container 1 through a fixing ring 14. The fixing ring 14 is fixedly connected to the side wall of the metal container 1, and the ultrasonic rod 11 is stuck in the fixing ring 14.

[0025] A lithium replenishing device for a negative electrode of a lithium ion battery also includes a thermometer 13. The thermometer 13 is arranged in a metal container 1.

[0026] The application process is:

[0027] Step 1) 1 mol / L LiPF6, 1.5 wt% fluoroethylene carbonate and ethylene carbonate are respectively placed in a metal container 1, an ultrasonic generator 12 is turned on, and ultrasonic treatment is performed for 10 minutes to allow the solution to be fully dissolved and mixed, thereby obtaining an electrolyte 10;

[0028] Step 2) Then, a metal lithium sheet 4, a separator 5, a negative electrode sheet 6 and a metal cover plate 7 are sequentially arranged from bottom to top; the negative electrode sheet 6 is located below the cylinder 3, and both ends of the negative electrode sheet 6 are connected to the reel 2; the electrolyte 10 covers the metal lithium sheet 4, the separator 5 and the negative electrode sheet 6, and is left to stand;

[0029] Step 3) Connect the metal cover plate 7 and the metal container 1 with a wire, and connect the resistor 8 and the switch 9 to the wire;

[0030] Step 4) closing the switch 9 and connecting the resistor 8 to replenish lithium;

[0031] Step 5) Turn off switch 9 and let the system stand.

[0032] The temperature change during the lithium replenishment process can be monitored by the thermometer 13. The negative electrode sheet 6 is replenished with lithium section by section, and the negative electrode sheet 6 after lithium replenishment is wound on the reel 2, and the negative electrode sheet 6 that has not been replenished with lithium is released into the electrolyte 10 to replenish lithium, and lithium replenishment is performed in this cycle.

[0033] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations. In addition, the various different embodiments of the present invention can also be arbitrarily combined, as long as they do not violate the idea of ​​the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A lithium replenishing device for a negative electrode of a lithium-ion battery, characterized in that: It includes a metal container, a reel, a cylinder, a metal lithium sheet, a diaphragm, a negative electrode sheet, a metal cover, a resistor and a switch; two reels are arranged above the metal container, the cylinder is fixedly arranged on the side wall of the metal container, the metal container is filled with electrolyte, and the metal lithium sheet, the diaphragm, the negative electrode sheet and the metal cover are arranged in sequence from bottom to top in the metal container; the negative electrode sheet is located below the cylinder, both ends of the negative electrode sheet are connected to the reel, and the electrolyte covers the negative electrode sheet; one end of the wire is connected to the metal cover, and the other end is connected to the bottom of the metal container, and the resistor and the switch are connected to the wire.

2. A lithium replenishing device for a negative electrode of a lithium-ion battery according to claim 1, characterized in that: The edge of the metal lithium sheet is 5 to 10 mm smaller than the diaphragm.

3. A lithium replenishing device for a negative electrode of a lithium-ion battery according to claim 1, characterized in that: The cylinder is a roller shaft.

4. A lithium replenishing device for a negative electrode of a lithium-ion battery according to claim 1, characterized in that: The number of the cylinders is two or more.

5. A lithium replenishing device for a negative electrode of a lithium-ion battery according to claim 1, characterized in that: It also includes an ultrasonic rod and an ultrasonic generator; the ultrasonic rod is arranged in the metal container, and the ultrasonic rod is connected to the ultrasonic generator.

6. A lithium replenishing device for a negative electrode of a lithium-ion battery according to claim 5, characterized in that: The ultrasonic rod is fixedly connected to the metal container via a fixing ring.

7. A lithium replenishing device for a negative electrode of a lithium-ion battery according to claim 1, characterized in that: Also included is a thermometer; the thermometer is disposed in the metal container.

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