Soft package battery cell beneficial to liquid supplementation

Abstract

The invention provides a soft package battery cell beneficial to liquid supplementation, and relates to the technical field of batteries, a body is formed by wrapping a naked battery cell with an aluminum plastic film, two groups of tabs are arranged on the side edge of the body, a liquid supplementation pipe is arranged on one side of the body, a liquid supplementation channel is arranged in the liquid supplementation pipe and is communicated with the interior of the body, and a plurality of hot melting parts are arranged on the outer wall of the liquid supplementation pipe. The liquid supplementing pipe is connected with the outer wall of the body through the hot melting part, the liquid supplementing channel is in a closed state when the hot melting part is connected with the body, a plurality of sealing strips are adhered to the outer wall of the liquid supplementing pipe, the aluminum-plastic film wraps the naked battery cell, a step part is formed on the outer edge after edge sealing, and the liquid supplementing pipe is folded outside the step part, so that the space for stacking the soft package battery in the later period is not influenced; and multiple times of sealing and liquid supplementing can be carried out through the tooth-shaped part and the hot melting part.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and more specifically, to a soft-pack battery cell that is conducive to liquid replenishment. Background Art

[0002] In recent years, with the popularity of mobile devices and the promotion of electric vehicles, the market demand for lithium-ion batteries has continued to increase. Lithium-ion batteries are a type of secondary battery (rechargeable battery). They generally use materials containing lithium as electrodes and rely mainly on the movement of lithium ions between the positive and negative electrodes to work. They are the representative of modern high-performance batteries. Lithium-ion batteries are divided into liquid lithium-ion batteries and polymer lithium-ion batteries. The main difference between them lies in the difference in electrolytes. Liquid lithium-ion batteries use liquid electrolytes, i.e. electrolytes, while polymer lithium-ion batteries use solid polymer electrolytes instead. This electrolyte can be a solid or colloidal polymer electrolyte. Currently, most of them use polymer gel electrolytes. As the use time of lithium-ion batteries increases, the electrolytes of both liquid lithium-ion batteries and polymer lithium-ion batteries will be lost, affecting the battery's rate, life and other performance.

[0003] Chinese patent application number CN2022109351794 discloses a soft-pack battery, a soft-pack battery pack and a large-capacity battery, which mainly solves the problem that the refilling device of the existing soft-pack battery has a complex structure, poor sealing and cannot realize electrolyte sharing. The soft-pack battery includes a soft-pack battery cell and a liquid injection device; the soft-pack battery cell includes a packaging film and an electrode assembly arranged in the packaging film; the liquid injection device includes a sealing film and a liquid injection tube, and the sealing film is connected to the packaging film; the liquid injection tube is completely embedded in the sealing film, or the liquid injection tube is partially embedded in the sealing film. The liquid injection device has a simple structure, and only a sealing film and a liquid injection tube need to be set. At the same time, the liquid injection device has good sealing. In addition, the liquid injection device can realize the sharing of electrolytes of multiple soft-pack batteries, so that the consistency of multiple soft-pack batteries after parallel connection is better.

[0004] The above scheme is to replenish the electrolyte through the injection device structure arranged on the outer wall of the soft-pack battery cell. Although this method can replenish the electrolyte while ensuring the sealing, it is worth noting that the soft-pack batteries need to be close to each other when arrayed to increase the energy density. How to provide higher energy density in a limited space has always been an important issue in the field of soft-pack batteries. The injection device in the above scheme will additionally increase the volume of the soft-pack battery cell, which leads to a decrease in the effective energy density. Summary of the invention

[0005] The technical problem to be solved by the present invention is that the liquid injection device in the traditional soft-pack battery cell will additionally increase the volume of the soft-pack battery cell, which leads to a decrease in the effective energy density. In view of the problems existing in the prior art, a soft-pack battery cell that is conducive to liquid replenishment is provided.

[0006] The purpose and effect of the present invention are achieved by the following specific technical means: A soft-pack battery cell that is conducive to liquid replenishment, comprising: The body is composed of bare cells wrapped in aluminum-plastic film, and two sets of tabs are set on the side of the body; A fluid infusion tube is arranged on one side of the main body, and a fluid infusion channel is arranged inside the fluid infusion tube, and the fluid infusion channel is communicated with the interior of the main body; The outer wall of the infusion tube is provided with a plurality of hot-melt parts, and the infusion tube is connected to the outer wall of the main body through the hot-melt parts, and the infusion channel is in a closed state when the hot-melt parts are connected to the main body; Several sealing strips are adhered to the outer wall of the infusion tube; This design allows for refilling via a refill tube, which can be folded onto the outer wall of the main body, thus reducing the volume occupied by the soft-pack battery cell.

[0007] A further preferred solution is that the aluminum-plastic film wraps the bare battery core and a step portion is formed on the outer edge after edge sealing.

[0008] A further preferred solution is that the connection position between the liquid infusion tube and the body is close to the position of the pole ear.

[0009] A further preferred solution is that teeth are provided on both sides of the infusion tube, and the teeth are composed of a plurality of concave and convex positions in the form of circular arcs, and the concave and convex positions of the infusion tube on both sides are symmetrically arranged.

[0010] A further preferred solution is that the heat-melting parts are arranged in parallel, and the distance between adjacent heat-melting parts is at least 3 cm; The hot melt portion is located between every two concave tooth-shaped portions.

[0011] A further preferred solution: the step portion and the outer wall of the body are provided with an adhesive portion near the step portion. The outer wall of the body is provided with a second adhesive portion at each concave tooth-shaped portion; The first adhesive portion and the second adhesive portion are both rough surfaces.

[0012] A further preferred solution is that the infusion tube is folded onto the outer wall of the main body, and sealing strips are adhered to the outer wall of the infusion tube at positions corresponding to the first and second adhesive parts, and the sealing strips are adhered to the first and second adhesive parts.

[0013] A further preferred solution: the adhesion widths between the first and second adhesive parts and the main body are at least 13 cm.

[0014] Beneficial effects of the present invention: A sealing strip is adhered to the outer wall of the liquid replenishment tube at a position corresponding to the adhesive part one. Pick up the sealing strip and stick it to the adhesive part one to seal the liquid replenishment tube at two consecutive places to prevent the internal electrolyte from leaking out when the battery cell is in a normal state. The liquid replenishment tube is connected to the outer wall of the main body through the hot melt part, and the liquid replenishment channel is in a closed state when the hot melt part is connected to the main body, which can achieve a secondary sealing effect. Pick up the sealing strip and stick it to the adhesive part two. Because there are multiple adhesive parts two, in order to ensure the sealing effect, multiple sealing strips can be used to stick to the adhesive part two. The sealing strip is placed horizontally outside the liquid injection tube to intercept the liquid injection channel of the liquid injection tube to prevent the internal electrolyte from leaking out when the battery cell is in a normal state.

[0015] When opening the refilling tube for refilling, cut along the convex position before the hot-melt portion, and the hot-melt portion loses its sealing effect. The refilling tube can be used for refilling again. After the refilling is completed, the hot-melt portion at the end of the refilling tube can be hot-melted with the main body again. Multiple sets of toothed portions and hot-melt portions can be used to perform sealing and refilling multiple times. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below in conjunction with the accompanying drawings.

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the connection between the main body and the liquid infusion tube structure of the present invention; Figure 3 For the present invention Figure 2 A local enlarged structural diagram of the part; Figure 4 Schematic diagram of the internal structure of the fluid infusion tube of the present invention.

[0018] Figure 1-Figure 4 Middle: main body (1), step portion (101), first adhesive portion (102), liquid infusion tube (2), liquid infusion channel (201), hot melt portion (202), toothed portion (3), second adhesive portion (4), sealing strip (5). DETAILED DESCRIPTION

[0019] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The following embodiments are only examples of implementing the present invention. It must be pointed out that the disclosed embodiments do not limit the scope of the present invention. On the contrary, changes and modifications made without departing from the scope of the present invention are all within the scope of patent protection of the present invention.

[0020] See also Figure 1-Figure 4 , a soft-pack battery cell that is conducive to liquid replenishment, comprising: The main body 1 is composed of a bare battery cell wrapped with an aluminum-plastic film. The aluminum-plastic film is a large-size film in the initial state. After punching holes on both sides of the aluminum-plastic film in the symmetrical direction, the bare battery cell is placed in one of the holes, and then the positive and negative pole tabs are welded to the pole tabs of the bare battery cell. The pole tabs will be exposed outside the aluminum-plastic film, and then the aluminum-plastic film is folded in half and sealed. The positive and negative pole tabs are sealed into the edge of the aluminum-plastic film. In order to better perform liquid injection and liquid replenishment in the later stage, a small distance is left outside the aluminum-plastic film without sealing the edge, which serves as a liquid replenishment port.

[0021] The liquid replenishment tube 2 is arranged on one side of the body 1 and corresponds to the liquid replenishment port. The liquid replenishment tube 2 can be a structure cut out of a large-size film in the initial state of the aluminum-plastic film. When the aluminum-plastic film is punched and the edges are sealed, the outer edge of the liquid replenishment tube 2 can be sealed together. A liquid replenishment channel 201 is arranged inside the liquid replenishment tube 2. The liquid replenishment channel 201 is communicated with the inside of the body 1 through the liquid replenishment port, and the battery cell can be injected with liquid through the liquid replenishment channel 201. Sealing steps: The bare battery core is wrapped with aluminum-plastic film and a step portion 101 is formed on the outer edge after the edge is sealed. The liquid replenishing tube 2 is folded outside the step portion 101 (such as Figure 2 As shown), it does not affect the space when the soft-pack batteries are stacked later. The step portion 101 and the outer wall of the body 1 are provided with an adhesive portion 102 near the step portion 101. The outer wall of the liquid replenishing tube 2 is adhered with a sealing strip 5 corresponding to the adhesive portion 102. The sealing strip 5 is picked up and adhered to the adhesive portion 102. The two adhesive portions 102 are both adhered with the sealing strip 5. At this time, the sealing strip 5 will be horizontally placed outside the liquid replenishing tube 2 to seal the liquid replenishing tube 2 at two consecutive locations to prevent the electrolyte from leaking out of the battery cell under normal conditions; Further sealing: The outer wall of the infusion tube 2 is provided with a plurality of hot-melt portions 202, and the infusion tube 2 is connected to the outer wall of the main body 1 through the hot-melt portions 202, and the infusion channel 201 is in a closed state when the hot-melt portions 202 are connected to the main body 1. When the infusion tube 2 is sealed for the first time, the hot-melt portion 202 at the end of the infusion tube 2 is hot-melt connected to the main body 1, which can achieve a secondary sealing effect; Further sealing: teeth are provided on both sides of the liquid infusion tube 2, and the teeth 3 are composed of a number of arc-shaped concave and convex positions, and the concave and convex positions of the liquid infusion tubes 2 on both sides are symmetrically arranged, and an adhesive portion 2 4 is provided on the outer wall of the main body 1 and at each concave tooth 3 position, and a sealing strip 5 is adhered to the outer wall of the liquid infusion tube 2 corresponding to the adhesive portion 2 4. Pick up the sealing strip 5 and stick it to the adhesive portion 2 4. Because there are multiple adhesive portions 2 4, in order to ensure the sealing effect, multiple sealing strips 5 can be used to stick to the adhesive portion 2 4. The sealing strip 5 is placed horizontally outside the liquid injection tube to intercept the injection channel of the liquid injection tube to prevent the electrolyte from leaking out of the battery cell under normal conditions.

[0022] The first adhesive part 102 and the second adhesive part 4 are both rough surfaces, and the friction force is greater when the sealing strip 5 is adhered to the first adhesive part 102 and the second adhesive part 4, which can effectively improve the sealing of the bonding and avoid loosening of the bonding; Specifically, the adhesive widths between the adhesive portion 1 102, the adhesive portion 2 4 and the main body 1 are at least 13 cm, and the adhesive area is large, which can also improve the adhesiveness.

[0023] Preferably, the toothed portions 3 arranged symmetrically on both sides of the infusion tube 2 are for facilitating the cutting and positioning of the end of the infusion tube 2, and each convex position is a cutting position, and the hot-melt portion 202 is located between each two concave toothed portions 3. When the infusion tube 2 is opened for infusion at a later time, it is cut along the convex position before the hot-melt portion 202, and the hot-melt portion 202 loses its sealing effect, and the infusion tube 2 can be used for infusion again. After the infusion is completed, the hot-melt portion 202 at the end of the infusion tube 2 can be hot-melted with the body 1 again, and multiple sealing and infusion can be performed through multiple groups of toothed portions 3 and hot-melt portions 202; The connection position between the liquid replenishing tube 2 and the main body 1 is close to the position of the pole ear, and the replenished electrolyte can quickly penetrate into the pole piece core without wasting time waiting for the core to be soaked.

[0024] The hot-melt portions 202 are arranged in parallel, and the distance between adjacent hot-melt portions 202 is at least 3 cm, so as to avoid the hot-melt portions 202 being too close to each other and causing the temperature of the adjacent hot-melt portions 202 to be affected.

Claims

1. A soft-pack battery cell that is easy to replenish liquid. It is characterized in that include: The body is composed of bare cells wrapped in aluminum-plastic film, and two sets of tabs are set on the side of the body; A fluid infusion tube is arranged on one side of the main body, and a fluid infusion channel is arranged inside the fluid infusion tube, and the fluid infusion channel is communicated with the interior of the main body; The outer wall of the infusion tube is provided with a plurality of hot-melt parts, and the infusion tube is connected to the outer wall of the main body through the hot-melt parts, and the infusion channel is in a closed state when the hot-melt parts are connected to the main body; A plurality of sealing strips are adhered to the outer wall of the infusion tube.

2. A soft-pack battery cell that facilitates liquid replenishment according to claim 1, Features: The aluminum-plastic film wraps the bare battery core and forms a step portion on the outer edge after edge sealing.

3. A soft-pack battery cell that facilitates liquid replenishment according to claim 1, Features: The connection position between the liquid replenishing tube and the body is close to the pole ear position.

4. A soft-pack battery cell that facilitates liquid replenishment according to claim 2, Features: The two sides of the infusion tube are both provided with toothed parts, and the toothed parts are composed of a plurality of concave and convex positions in the form of circular arcs, and the concave and convex positions of the infusion tubes on both sides are symmetrically arranged.

5. A soft-pack battery cell that facilitates liquid replenishment according to claim 1, Features: The hot-melt portions are arranged in parallel, and the distance between adjacent hot-melt portions is at least 3 cm; The hot melt portion is located between every two concave tooth-shaped portions.

6. A soft-pack battery cell that facilitates liquid replenishment according to claim 4, Features: The step portion and the outer wall of the main body are provided with an adhesive portion near the step portion. The outer wall of the body is provided with a second adhesive portion at each concave tooth-shaped portion; The first adhesive portion and the second adhesive portion are both rough surfaces.

7. A soft-pack battery cell that facilitates liquid replenishment according to claim 6, Features: The infusion tube is folded on the outer wall of the main body, and sealing strips are adhered to the positions of the outer wall of the infusion tube corresponding to the first adhesive part and the second adhesive part, and the sealing strips are adhered to the first adhesive part and the second adhesive part.

8. A soft-pack battery cell that facilitates liquid replenishment according to claim 7, Features: The adhesion widths between the first adhesive portion, the second adhesive portion and the main body are at least 13 cm.

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