CN107359307B - Lithium ion battery pole piece lithium supplementing device - Google Patents

Abstract

The invention belongs to the technical field of pole piece processing devices, and in particular relates to a lithium ion battery pole piece lithium replenishing device, comprising a pole piece unwinding device, a pole piece winding device, a metal lithium cold pressing device and a metal lithium supply device. The lithium device is arranged between the pole piece unwinding device and the pole piece winding device, the metal lithium cold pressing device is arranged between the metal lithium supply device and the pole piece winding device, and the metal lithium supply device is set as an extruded metal lithium supply device. device. The invention can process the pole pieces efficiently, quantitatively and uniformly, has simple structure, low cost, relatively low environmental requirements, and realizes industrialized mass production and supply.

Description

Lithium-ion battery pole piece lithium replenishment device

This application is a divisional application for an invention patent application with the application number of 201310461257.2, the application date of which is on October 8, 2013, and the invention name is "Lithium Replenishing Device for Lithium-ion Battery Pole Piece".

technical field

The invention belongs to the technical field of pole piece processing devices, and in particular relates to a lithium ion battery pole piece lithium replenishing device.

Background technique

Since the commercialization of lithium-ion battery materials by Sony Corporation of Japan, lithium-ion batteries are rapidly gaining popularity in portable portable devices due to their light weight, high voltage, small size, no memory effect, high specific energy, long cycle life, and environmental friendliness. Portable electronic products such as mobile power, mobile phones, portable computers, cameras and video cameras are popularized and applied, and occupy an important position in the energy field.

With the continuous expansion of the application field of lithium-ion batteries, various products have higher and higher performance requirements for lithium-ion batteries. For example, miniaturized portable electronic products require lithium-ion batteries to have a long service time, so there is an increasing requirement for the energy density of lithium-ion batteries. For the existing negative electrode materials, not only will a part of the lithium ions from the positive electrode material be consumed due to the formation of a solid electrolyte membrane (SEI film) during the first charging process, but also a part of the lithium ions will be irreversibly extracted from the negative electrode material. The first coulombic efficiency of lithium-ion batteries cannot reach 100%. For example, the first coulombic efficiency of graphite materials is about 90%. Other anode materials such as silicon anode materials have higher specific capacities, but their first coulombic efficiency is only 65-85%. %between. Therefore, if the lithium ions in the positive electrode material lost in the negative electrode material can be supplemented additionally, the energy density of the lithium ion battery can be greatly improved.

One method of extra lithium supplementation is to add a part of metal lithium to the pole piece in advance before preparing the battery cell. For example, the Chinese patent application with the application number of 201210237240 uses the expensive metal lithium powder to make the metal lithium powder by applying voltage and vibration. The powder is attached to the pole piece, and then the lithium-supplemented pole piece is obtained by cold pressing. The lithium replenishment process of attaching metal lithium powder to the pole piece in this application requires high-precision equipment, and this method is mainly realized by electrostatic vibration, which is difficult to ensure uniformity and difficult to monitor the amount of lithium replenishment. The environmental requirements are extremely high, and the scattered metal lithium powder needs to be placed in special equipment for processing, and the efficiency is low.

Because it is difficult to obtain continuous thin metal lithium strips under the current technical conditions, and because of the poor mechanical properties of metal lithium, it is difficult to attach thin metal lithium to the pole piece. If metal lithium is attached to the pole piece, the production efficiency of this mechanism is very low, and it is difficult to meet the requirements of mass production. At the same time, the method of evaporation requires high control precision and the waste of metal lithium is serious.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a lithium ion battery pole piece lithium replenishing device, which can quickly, efficiently, uniformly and quantitatively attach metal lithium to the pole piece of the lithium ion battery.

In order to achieve the above object, the present invention adopts the following technical solutions: a lithium ion battery pole piece lithium replenishing device, including a pole piece unwinding device, a pole piece winding device, a metal lithium cold pressing device and a metal lithium supply device, the metal lithium supply The device is arranged between the pole piece unwinding device and the pole piece winding device, the metal lithium cold pressing device is arranged between the metal lithium supply device and the pole piece winding device, and the metal lithium supply The device is configured as an extruded metal lithium supply device.

The extrusion type metal lithium supply device includes a pressurization mechanism, a pressure transmission mechanism, a metal lithium wire extrusion head and a metal lithium wire extrusion shell, and the metal lithium wire extrusion head is arranged in the metal lithium wire extrusion shell. inside, and the metal lithium wire extrusion head is connected with the pressurizing mechanism through the pressure transmission mechanism, and the bottom of the metal lithium wire extrusion shell is provided with an extrusion nozzle.

The extrusion type metal lithium supply device further includes a metal lithium cooling mechanism, and the metal lithium wire extrusion shell is arranged in the metal lithium cooling mechanism.

The metal lithium cooling mechanism is an air-cooled metal lithium cooling mechanism or a liquid-cooled metal lithium cooling mechanism.

The metal lithium wire extrusion head is sealedly connected with the pressurizing mechanism through the pressure transmission mechanism.

The pressurizing mechanism is configured as a pneumatic pressurizing mechanism, a hydraulic pressurizing mechanism or an electric pressurizing mechanism.

The pole piece unwinding device includes an unwinding roller, an unwinding tension adjusting roller, a positioning roller and a first transmission roller arranged in sequence, and the extrusion nozzle is arranged corresponding to the first transmission roller.

The pole piece winding device includes a protection baffle, a fixed frame, a deviation correction detector, a second transmission roller, a winding tension adjustment roller and a winding roller, the deviation correction detector is arranged on the fixed frame, and the protective barrier The plate is arranged at the top of the fixing frame, the second driving roller is arranged at the bottom of the fixing frame, and the winding tension adjusting roller is located between the second driving roller and the winding roller.

The lithium metal cold pressing device includes a cold pressing driving roller and a cold pressing driven roller arranged side by side with the cold pressing driving roller, and a gap is set between the cold pressing driving roller and the cold pressing driven roller.

Compared with the prior art, the present invention has at least the following advantages: 1) The present invention combines the preparation of the metal lithium required for the battery cell with the lithium replenishment process, wherein the lithium replenishment process squeezes the metal lithium wire on the pole of the drying process; On the chip, after cold pressing, the lithium-ion battery pole piece lithium replenishment process is realized. The lithium replenishment device can complete lithium replenishment in a low-humidity normal temperature environment, which greatly reduces the environmental requirements of the lithium replenishment process. 2) In the present invention, the extrusion head can be exchanged according to the requirements of the process, so that the amount of lithium replenishment can be controlled, and if a double extrusion head is used, the lithium replenishment on both sides can be performed simultaneously; and the invention has a simple structure and high production efficiency. 3) The lithium used in the present invention is a metal lithium ingot with low cost; only the lithium ingot can be extruded at room temperature, and the process is very simple; therefore, it is extremely easy to realize industrialized mass production.

Description of drawings

FIG. 1 is a schematic structural diagram of the present invention.

FIG. 2 is an enlarged view of part A of FIG. 1 .

Among them, 1 - pole piece unwinding device, 2 - pole piece winding device, 3 - metal lithium cold pressing device, 4 - metal lithium supply device, 11 - unwinding roller, 12 - unwinding tension Adjusting roller, 13—positioning roller, 14—first drive roller, 21—protection baffle, 22—fixed frame, 23—correction detector, 24—second drive roller, 25—winding Tension adjusting roller, 26-winding roller, 31-cold pressing driving roller, 32-cold pressing driven roller, 41-pressurizing mechanism, 42-pressure transmission mechanism, 43-metal lithium wire extrusion Head, 44—metal lithium wire extrusion shell, 45—metal lithium cooling mechanism, 46—extrusion nozzle.

Detailed ways

The present invention will be described in further detail below with reference to the specific embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

DETAILED DESCRIPTION 1, as shown in FIG. 1, a lithium-ion battery pole piece lithium replenishing device includes a pole piece unwinding device 1, a pole piece winding device 2, a metal lithium cold pressing device 3 and a metal lithium supply device 4, and a metal lithium The supply device 4 is arranged between the pole piece unwinding device 1 and the pole piece winding device 2, the metal lithium cold pressing device 3 is arranged between the metal lithium supply device 4 and the pole piece winding device 2, and the metal lithium supply device 4 is arranged It is an extrusion type metal lithium supply device, and the extrusion type metal lithium supply device includes a pressurizing mechanism 41, a pressure transmission mechanism 42, a metal lithium wire extrusion head 43 and a metal lithium wire extrusion shell 44, and the metal lithium wire extrusion head 43 It is arranged in the metal lithium wire extrusion shell 44, and the metal lithium wire extrusion head 43 is connected with the pressurization mechanism 41 through the pressure transmission mechanism 42. The metal lithium wire extrusion head 43 is made of high-pressure metal material, and is surface-treated with The cohesiveness of metal lithium is low, so that it is easier to extrude metal lithium. The pressurizing mechanism 41 is set as a pneumatic pressurizing mechanism, and the bottom of the metal lithium wire extrusion shell 44 is provided with an extrusion nozzle 46. The extrusion nozzle 46 The shape of the cross section is square, oval, circle or trapezoid, and the size of the extrusion nozzle 46 can be set as required. In the present invention, the lithium replenishment of the pole piece is performed by applying a certain force through the pressure transmission mechanism 42 so that the extrusion nozzle 46 can quantitatively and uniformly attach the metal lithium to the dried pole piece.

The extrusion type metal lithium supply device also includes a metal lithium cooling mechanism 45, and the metal lithium wire extrusion shell 44 is arranged in the metal lithium cooling mechanism 45. Generally, the metal lithium cooling mechanism 45 is an air-cooled metal lithium cooling mechanism. The metal lithium cooling mechanism has a cooling effect on the metal lithium during the extrusion process, and reduces the resistance caused by the bonding between the metal lithium and the metal lithium wire extrusion head 43 .

Preferably, the metal lithium wire extrusion head 43 is sealedly connected to the pressurizing mechanism 41 through the pressure transmission mechanism 42, so as to ensure the uniformity of the force during the extrusion process of the metal lithium wire.

The pole piece unwinding device 1 includes an unwinding roller 11, an unwinding tension adjusting roller 12, a positioning roller 13 and a first driving roller 14 arranged in sequence. The extrusion nozzle 46 is arranged corresponding to the first driving roller 14. The outgoing metal lithium is attached to the pole piece on the first transmission roller 14 by being driven by the first transmission roller 14 .

The pole piece winding device 2 includes a protection baffle 21, a fixed frame 22, a deviation correction detector 23, a second transmission roller 24, a winding tension adjustment roller 25 and a winding roller 26. The deviation correction detector 23 is arranged on the fixed frame 22 to protect the The baffle 21 is arranged on the top of the fixing frame 22 for protection, the second driving roller 24 is arranged at the bottom of the fixing frame 22, the winding tension adjusting roller 25 is located between the second driving roller 24 and the winding roller 26, The tension of the winding can be adjusted in time as needed. When the deviation correction detector 23 detects that the pole piece winding is deviated, the winding roller 26 will correct the deviation after receiving the signal, so as to achieve a good winding effect.

The lithium metal cold pressing device 3 includes a cold pressing driving roll 31 and a cold pressing driven roll 32 arranged side by side with the cold pressing driving roll 31. Of course, the cold pressing driving roll 31 and the cold pressing driven roll 32 can be interchanged, not necessarily in The top is the cold-pressed driving roller 31, and the bottom must be the cold-pressed driven roller 32. Both the cold-pressed driving roller 31 and the cold-pressed driven roller 32 have undergone surface treatment to reduce the adhesion with metal lithium, and the cold-pressed active roller 32 has undergone surface treatment. There is a gap between the roller 31 and the cold-pressed driven roller 32. The size of the gap is used to realize the size of the contact area between the metal lithium and the pole piece. The smaller the gap, the better the adhesion between the corresponding metal lithium and the pole piece, and vice versa. The worse the knot.

In the drying room, put the baked lithium pole piece core to be replenished on the unwinding roller 11 and pass through the unwinding tension adjustment roller 12, the positioning roller 13, the first transmission roller 14, and the metal lithium cold pressing device 3 in turn. (ie, the cold-pressing driving roller 31 and the cold-pressing driven roller 32), the second driving roller 24, the winding tensioning roller 25 and the winding roller 26, among which the unwinding roller 11, the unwinding tensioning roller 12, the positioning roller 13 , The first drive roller 14, the protection baffle 21, the deviation correction detector 23, the second drive roller 24, the winding tension adjusting roller 25 and the winding roller 26 work together to realize the continuity of lithium replenishment of the pole piece, which greatly improves the work efficiency. And control the leveling and neat stacking of the lithium-replenishing film roll. After the pole pieces are fixed as described above, the booster mechanism 41 starts to work, and after the pressure increases, the pressure transmission mechanism 42 starts to work to squeeze the solid metal lithium in the metal lithium wire extrusion head 43, and the metal lithium after being pressed starts to work. Extruded from the extrusion nozzle 46, at this time the pole piece unwinding device 1, the pole piece winding device 2 and the metal lithium cold pressing device 3 start to work, and the metal lithium wire comes out of the metal lithium wire extrusion head 43 and adheres to the On the continuously moving pole piece, when the pole piece attached with the metal lithium wire passes through the gap between the cold-pressed driving roller 31 and the cold-pressed driven roller 32, the metal lithium wire is flattened, so that the area of lithium replenishment is increased, and at the same time, the lithium metal wire is flattened. To achieve good adhesion between metal lithium and the pole piece. When the pressure transmission mechanism 42 starts to work, the metal lithium will rub against the metal lithium wire extrusion head 43 to generate a lot of heat, which will not only increase the bonding force between the metal lithium and the metal lithium wire extrusion head 43, but also change the heat This will lead to an increase in the fluidity and reactivity of the metal, resulting in a change in the amount of lithium supplementation. At this time, the metal lithium cooling mechanism 45 is turned on to cool the internal metal lithium, so that the lithium supplementation process is controllable. By controlling the shape of the metal lithium wire extrusion head 43, metal lithium with different thicknesses and shapes can be obtained, and the amount of lithium supplementation can be adjusted.

The specific embodiment 2 is different from the specific embodiment 1 in that the metal lithium cooling mechanism 45 in this embodiment is a liquid-cooled metal lithium cooling mechanism, and the liquid-cooled metal lithium cooling mechanism has a more obvious cooling effect on the metal lithium. , the pressurizing mechanism 41 is set as a hydraulic pressurizing mechanism, and is matched with the metal lithium cooling mechanism 45, so that the structure of the present invention is simpler.

Other structures are the same as those of the specific embodiment 1, and are not repeated here.

The specific embodiment 3 is different from the specific embodiment 2 in that the supercharging mechanism 41 of this embodiment is set as an electric supercharging mechanism, which meets the modern setting requirements, and the power effect of the electric supercharging mechanism is better.

Other structures are the same as those of the specific embodiment 2, and are not repeated here.

To sum up, by using the lithium ion battery pole piece lithium replenishing device, the uniform, quantitative and efficient treatment of the pole piece can be very effectively realized; at the same time, the present invention combines the two processes of metal lithium wire preparation and pole piece lithium replenishment. The two are one, the metal lithium used is a metal lithium ingot, and the pole piece is a pole piece after coating and baking treatment, so the device has a simple structure, low cost, and is extremely easy to realize industrialized mass production.

Based on the disclosure and teaching of the above specification, those skilled in the art to which the present invention pertains can also make changes and modifications to the above-described embodiments. Therefore, the present invention is not limited to the above-mentioned specific embodiments, and any obvious improvement, replacement or modification made by those skilled in the art on the basis of the present invention falls within the protection scope of the present invention. In addition, although some specific terms are used in this specification, these terms are only for convenience of description and do not constitute any limitation to the present invention.

Claims (4)

1. Lithium-ion battery pole piece lithium replenishing device, including pole piece unwinding device, pole piece winding device and metal lithium supply device, and the metal lithium supply device is arranged on the pole piece unwinding device and the pole piece winding device. It is characterized in that: the metal lithium supply device is provided with a metal lithium cooling mechanism, and the metal lithium supply device is configured as an extrusion type metal lithium supply device, The extrusion-type metal lithium supply device includes a metal lithium wire extrusion head for extruding solid metal lithium in the metal lithium wire extrusion head, The lithium ion battery pole piece lithium replenishing device further includes a metal lithium cold pressing device, and the metal lithium cold pressing device is arranged between the metal lithium supply device and the pole piece winding device. 2 . The lithium-ion battery pole piece lithium replenishing device according to claim 1 , wherein the metal lithium cooling mechanism is an air-cooled metal lithium cooling mechanism or a liquid-cooled metal lithium cooling mechanism. 3 . 3. The lithium-ion battery pole piece lithium replenishing device according to claim 1, wherein the pole piece winding device comprises a protective baffle, a fixing frame, a deviation correction detector, a second transmission roller, and a winding tension adjustment roller and winding roller, the deviation correction detector is arranged on the fixing frame, the protection baffle is arranged on the top of the fixing frame, the second driving roller is arranged at the bottom of the fixing frame, the retracting A roll dancer roll is located between the second drive roll and the take-up roll. 4 . The lithium ion battery pole piece lithium supplementing device according to claim 1 , wherein the metal lithium cold pressing device comprises a cold pressing driving roller and a cold pressing driven roller arranged side by side with the cold pressing driving roller. 5 . , a gap is set between the cold-pressing driving roller and the cold-pressing driven roller.

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