Battery three-dimensional interlayer diaphragm structure with graded liquid retention capacity

A diaphragm structure and interlayer technology, which is applied in the field of battery three-dimensional interlayer diaphragm structure, can solve problems such as affecting battery safety performance, affecting battery rate performance, and reducing the amount of electrolyte, preventing battery safety and electrical performance problems, and having great practical significance in production. , The effect of structural design science

Pending Publication Date: 2020-07-03
LISHEN (QINGDAO) NEW ENERGY CO LTD
0 Cites 0 Cited by

AI-Extracted Technical Summary

Problems solved by technology

[0003] At present, the arrangement of batteries in the battery pack (PACK) is mainly vertical placement. This placement will inevitably cause the electrolyte to partially accumulate at the bottom of the battery due to gravity.
When the electrolyte needs to be activated, it often takes a certain amount of time to transfer the electrolyte from the bottom to the upper part, so there will be a concentration difference, which seriously affects t...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Method used

3, the battery three-dimensional sandwich membrane structure of the present invention can keep the electrolyte segmented in different areas of the battery height, and realize the pole piece coating amount and electrolysis by controllable customization of the graded channel position, depth and density The matching of the liquid volume avoids the waste of electrolyte and the safety problems caused by the lack of electrolyte.
5, battery three-dimensional interlayer diaphragm structure of the present invention is because electrolytic solution is retained in directional distribution on diaphragm height direction, relative to other structures, can accelerate the infiltration of pole piece, has reduced the standing time in production process, promoted Productivity.
[0041] It should be noted that the base film 11 of the front surface layer and the base film 12 of the back surface layer are both planar layers, which are two-layer planar structures, and the liquid storage interlayer in the middle is a three-dimensional V-shaped channel. The planar layer of the basement membrane and the reservoir interlayer are controllably assembled into a three-dimensional sandwich structure. This three-dimensional structure can realize controllable grading by adjusting the size of the interlayer structure and the density between layers. The electro-hydraulic is stored in differ...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Abstract

The invention discloses a battery three-dimensional interlayer diaphragm structure with graded liquid retention capacity. The battery three-dimensional interlayer diaphragm structure comprises a frontsurface layer base film (11) and a rear surface layer base film (12) which are distributed at intervals front and back, wherein a plurality of transversely distributed liquid storage interlayers (2)are arranged in a cavity between the front surface layer base film (11) and the rear surface layer base film (12) at intervals from top to bottom, the liquid storage interlayers (2) are used for dividing the cavity between the front surface layer base film (11) and the rear surface layer base film (12) into a plurality of independent liquid storage channels, each liquid storage interlayer (2) comprises a plurality of interlayer single bodies (4) which are sequentially connected together, each interlayer single body is of a groove structure with an upward opening, and an intercommunicating hole(3) which is vertically through up and down is formed in the joint of any two adjacent interlayer single bodies. The battery three-dimensional interlayer diaphragm structure is scientific in structural design, and controllably achieves the graded storage of an electrolytic solution at different height levels, so that the problems of battery safety and electrical performance caused by lack of electrolytic solution are prevented.

Application Domain

Technology Topic

Diaphragm structureElectrical battery +6

Image

  • Battery three-dimensional interlayer diaphragm structure with graded liquid retention capacity
  • Battery three-dimensional interlayer diaphragm structure with graded liquid retention capacity
  • Battery three-dimensional interlayer diaphragm structure with graded liquid retention capacity

Examples

  • Experimental program(1)

Example Embodiment

[0024] In order to enable those skilled in the art to better understand the solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.
[0025] See Figure 1 to Figure 4 , The present invention provides a three-dimensional battery sandwich diaphragm structure with hierarchical liquid retention capability, including a front surface layer base film 11 and a back surface layer base film 12 distributed at intervals between front and rear;
[0026] In the cavity between the front surface layer base film 11 and the back surface layer base film 12, a plurality of laterally distributed liquid storage interlayers 2 are sequentially spaced from top to bottom;
[0027] The liquid storage interlayer 2 is used to divide the cavity between the front surface layer base film 11 and the back surface layer base film 12 into a plurality of independent liquid storage channels (ie, multi-level electrolyte storage channels and cavities);
[0028] Each liquid storage interlayer 2 includes a plurality of interlayer monomers 4 connected together in sequence;
[0029] The interlayer monomer 4 is a groove structure with an upward opening (bottom seal);
[0030] At the junction between any two adjacent interlayer monomers 4, an interconnecting hole 3 that penetrates vertically up and down is opened.
[0031] In the present invention, in terms of specific implementation, a plurality of liquid storage interlayers 2 are distributed at equal intervals in the cavity between the front surface layer base film 11 and the back surface layer base film 12.
[0032] In the present invention, in terms of specific implementation, the sandwich monomer 4 is preferably a V-shaped or concave-shaped structure with an upward opening, but it is not limited to this shape.
[0033] In the present invention, in terms of specific implementation, the liquid storage interlayer 2 exists between the two base film plane layers (ie, the front surface layer base film 11 and the back surface layer base film 12), and they are combined together by glue.
[0034] In the present invention, the thickness of the base film 11 of the front surface layer and the base film 12 of the rear surface layer is 2-50um.
[0035] In the present invention, in terms of specific implementation, the depth and width of the channel connecting the interconnecting holes 3 in the liquid storage interlayer 2 can be flexibly designed according to the amount of liquid injected, and the size range is all included in the protection scope of this patent.
[0036] It should be noted that, for the present invention, after the electrolyte is injected, it will be retained in stages in the multi-level liquid storage channels of the diaphragm structure of the battery cell in different height directions. And there are certain interconnected holes between the multilayer channels, but it does not affect the long-term storage of electrolyte in the channels.
[0037] In the present invention, the material of the base film 11 of the front surface layer and the base film 12 of the rear surface layer can be made of polyolefin materials, prepared by the existing dry method or wet method, and can adopt the mature technology of the prior art. Battery separator base film.
[0038] In the present invention, the liquid storage interlayer 2 located between the front surface layer base film 11 and the rear surface layer base film 12 is a three-dimensional structure made of PVDF (polyvinylidene fluoride) glue (but not limited to PVDF substances, all materials that can meet the design structure are within the protection range), the size of the PVDF raw material powder is nanometer, the amorphous region is maintained in the range of 10-40%, and the weight ratio is 20%-67%. The nanometer-level PVDF powder is dissolved in NMP (N-methylpyrrolidone) or DMF (dimethylformamide) or betaine BS-12 emulsion. The heating temperature is above 30℃ and the stirring time is 30min to fully dissolve the nanometer grade. PVDF, until the glue viscosity is 2000~7000/cp.
[0039] In the present invention, in terms of specific implementation, the specific preparation process of the battery three-dimensional sandwich separator structure of the present invention is as follows: First, according to the settings, on the surface of the polyolefin rear surface layer base film 12, through a mold injection method (existing ) To form a preliminary composite of a continuous interlayer (ie, multiple liquid storage interlayers 2) and the base film 12 of the back surface layer to obtain a preliminary composite, in which two V-shaped interlayer monomers 4 are left with small gaps (interconnecting holes 3). ) To ensure that the electrolyte can be transferred between the multilayer liquid storage channels when the electrolyte is injected; subsequently, the front surface layer base film 11 is covered on the front surface of the liquid storage interlayer 2, and the thermal temperature is controlled to 50-120°C, The preliminary composite body is bonded to the front surface layer base film 11 to finally form a three-dimensional battery sandwich diaphragm structure.
[0040] It should be noted that for the liquid storage interlayer 2, the colloid used should not be limited to the PVDF glue, including the scope extended to any material that can form the original shape. The method protection is not limited to the above methods, and should include any method for preparing the sandwich structure.
[0041] It should be noted that the front surface layer base film 11 and the back surface layer base film 12 are both planar layers, which have a two-layer planar structure, and the liquid storage interlayer in the middle is a three-dimensional V-shaped channel. The base membrane plane layer and the liquid storage interlayer are controllably assembled into a three-dimensional interlayer structure. This three-dimensional structure can achieve controllable grading by adjusting the size of the sandwich structure and the interlayer density to store the electro-hydraulic in different interlayer channels, matching the needs of different pole piece positions for the electrolyte, improving the liquid retention capacity of the diaphragm, and accelerating The reaction speed of the ions in the electrolyte is improved, which improves the rate performance of the battery. At the same time, this structure also avoids the uneven distribution of electrolyte in the electrode group caused by uneven tension, solves the phenomenon of lithium evolution caused by this, and improves the safety performance of the battery. In addition, through the multi-level and designability of the channel distribution, the present invention can realize the effect of the controllable and hierarchical distribution of the electrolyte according to the difference of the coating amount at different positions of the pole piece. None of the current diaphragm materials have this structure.
[0042] In order to make the technical solution of the present invention clearer, the following description will be given in conjunction with specific embodiments.
[0043] See Figure 1 to Figure 4 As shown, a battery three-dimensional sandwich diaphragm structure with hierarchical liquid retention capacity of the present invention includes a surface layer and a sandwich body (that is, a front surface layer base film 11, a rear surface layer base film 12, and a liquid storage interlayer). The liquid interlayer 2 has a V shape and can store electro-hydraulic in the tunnel.
[0044] The base film 11 of the front surface layer and the base film 12 of the rear surface layer are made of polyolefin material and are prepared by dry stretching; the liquid storage interlayer in the middle is a three-dimensional structure of PVDF glue, and the size of the PVDF raw material powder is nanometer and amorphous Zone retention range 22%, dissolve nanometer PVDF in NMP or water-based solvent, heating temperature 50℃, stirring time 60min, fully dissolve nanometer PVDF, until the glue reaches a viscosity of 5600cp. According to the setting, on the height direction surface (ie the front side) of the back surface layer base film 12, through the injection molding method, a preliminary composite of the multilayer sandwich body and the back surface layer base film is formed. Small gaps to ensure the transfer between multiple layers when electrolyte is injected. Subsequently, the front surface of the interlayer is covered with a base film of the front surface layer, and the heat temperature is controlled to 60° C. to bond the preliminary composite with the base film of the front surface layer to form the three-dimensional sandwich structure.
[0045] For the present invention, according to the difference in the distribution of the coating amount of the pole pieces, the upper side of the height direction of the battery is designed, the pore level is slightly sparse, and the electrolyte retained slightly. In the same way, the pores on the lower side are dense and can store a lot of electrolyte.
[0046] Compared with the prior art, the three-dimensional battery sandwich diaphragm structure with hierarchical liquid retention capability provided by the present invention has the following beneficial effects:
[0047] 1. The three-dimensional sandwich diaphragm structure of the battery of the present invention can avoid the disadvantages of the electrolyte concentration gradient distribution caused by the vertical placement of the battery. Its unique liquid retention structure can make the lithium ions in the electrolyte start quickly and improve the battery's electricity performance.
[0048] 2. The three-dimensional sandwich diaphragm structure of the battery of the present invention can effectively infiltrate the electrolyte, avoiding the lithium evolution caused by the lack of electrolyte in some areas, and greatly reducing the safety risk of the battery.
[0049] 3. The three-dimensional sandwich diaphragm structure of the battery of the present invention can keep the electrolyte in different areas of the battery height. The position, depth and density of the grading channel can be controlled and customized to achieve the difference between the coating amount of the pole piece and the amount of electrolyte. Matching avoids waste of electrolyte and safety problems caused by lack of electrolyte.
[0050] 4. In the three-dimensional sandwich diaphragm structure of the battery of the present invention, the nano-scale PVDF particles used in the sandwich structure can achieve effective retention of electrolyte. At the same time, the sandwich structure can reduce the risk of diaphragm contraction due to temperature rise to a certain extent, and can also play a buffering effect on the direct piercing of the diaphragm by foreign matter in the process, thereby avoiding safety problems caused by this.
[0051] 5. The three-dimensional sandwich diaphragm structure of the battery of the present invention retains the electrolyte in the directional distribution in the height direction of the diaphragm. Compared with other structures, it can accelerate the infiltration of the pole pieces, reduce the standing time in the production process, and improve the production efficiency.
[0052] 6. The three-dimensional sandwich diaphragm structure of the battery of the present invention has strong designability.
[0053] In summary, compared with the prior art, the present invention provides a three-dimensional battery sandwich diaphragm structure with hierarchical liquid retention capability. Its structural design is scientific, and the electrolyte can be controlled to achieve hierarchical storage at different height levels, thereby It prevents battery safety and electrical performance problems caused by lack of electrolyte, which is of great production and practical significance.
[0054] In addition, the three-dimensional battery sandwich diaphragm structure with hierarchical liquid retention capability provided by the present invention has high flexibility, and can flexibly design the channel size, distribution position and density according to the difference in coating amount at different positions of the pole pieces, thereby controlling the orientation Distribute electro-hydraulic. All current diaphragms do not have this structure and function.
[0055] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications are also It should be regarded as the protection scope of the present invention.
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Thickness2.0 ~ 50.0µm
tensileMPa
Particle sizePa
strength10

Description & Claims & Application Information

We can also present the details of the Description, Claims and Application information to help users get a comprehensive understanding of the technical details of the patent, such as background art, summary of invention, brief description of drawings, description of embodiments, and other original content. On the other hand, users can also determine the specific scope of protection of the technology through the list of claims; as well as understand the changes in the life cycle of the technology with the presentation of the patent timeline. Login to view more.
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Similar technology patents

Classification and recommendation of technical efficacy words

Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products