Protective film for packaging battery cell and energy storage battery with same

Abstract

The utility model discloses a protective film for packaging a battery cell and an energy storage battery with the protective film. The protective film comprises a first protective layer, a lithium supplementing layer and a second protective layer, the lithium supplementing layer is arranged on one side of the first protective layer and can release lithium ions; the second protection layer is arranged on the side, away from the first protection layer, of the lithium supplement layer, a release channel is formed in the second protection layer, and lithium ions can enter the battery solution through the release channel. Therefore, the protective film is arranged on the outer side of the battery cell, so that the lithium supplementing layer in the middle of the protective film can dissipate lithium ions in the lithium supplementing layer when the lithium ions in the battery solution are insufficient, and the lithium ions enter the battery solution through the release channel to supplement the concentration of the lithium ions in the battery solution; therefore, the lithium ions in the battery solution can keep high solubility, so that the battery solution has good energy storage capacity, the use performance of the battery is improved, and the service life of the battery is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a protective film for packaging electric cores and an energy storage battery having the protective film. Background Art

[0002] In the prior art, during the long-term use of energy storage batteries, the lithium ions in the battery will escape, which will affect the performance of the battery. Therefore, in the related art, a special device is usually provided to replenish the lithium ions in the battery. Although it can replenish the number of lithium ions in the battery well, the use of the corresponding device will also increase the production cost. During the use of the battery, an isolation protective film will be coated on the outside of the battery. How to use the protective film to replenish the lithium ions in the battery is an urgent problem to be solved. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the utility model is to provide a protective film for packaging a battery cell, which can not only protect the battery but also replenish the lithium ions in the battery to improve the performance of the battery.

[0004] Another object of the utility model is to provide an energy storage battery, wherein the protective film as shown above is provided inside the energy storage battery.

[0005] According to an embodiment of the utility model, a protective film for packaging a battery cell comprises: a first protective layer, a lithium replenishing layer, and a second protective layer; the lithium replenishing layer is arranged on one side of the first protective layer, and the lithium replenishing layer can release lithium ions; the second protective layer is arranged on the side of the lithium replenishing layer away from the first protective layer, and a release channel is arranged on the second protective layer, and the lithium ions can enter the battery solution through the release channel.

[0006] According to the protective film for packaging the battery cell of the embodiment of the utility model, the protective film is arranged on the outside of the battery cell so that when the lithium ions in the battery solution are insufficient, the lithium ions in the lithium replenishing layer in the middle of the protective film can escape and enter the battery solution through the release channel to replenish the lithium ion concentration in the battery solution, so that the lithium ions in the battery solution can maintain a high solubility, so that the battery solution has a better energy storage capacity, so that the performance and service life of the battery are improved.

[0007] In some embodiments, the lithium supplement layer includes: a lithium supplement agent and a binder, and the lithium supplement agent and the binder are uniformly mixed.

[0008] In some embodiments, the proportion of the lithium replenishing agent in the lithium replenishing layer is α, and the proportion α satisfies the relationship: α≥70%.

[0009] In some embodiments, the release channels are a plurality of through-holes arranged at intervals.

[0010] In some embodiments, the total area of the release channels is A, the longitudinal cross-sectional area of the second protective layer is B, and the total area A and the cross-sectional area B satisfy the relationship: 10% B ≤ A ≤ 50% B.

[0011] In some embodiments, the thickness of the first protective layer is C, the thickness of the second protective layer is D, and the thickness C and the thickness D satisfy the relationship: 50 μm ≤ C ≤ 150 μm, 50 μm ≤ D ≤ 150 μm.

[0012] In some embodiments, both the first protective layer and the second protective layer are polypropylene (PP) films.

[0013] In some embodiments, the thickness of the lithium supplement layer is E, and the thickness E satisfies the relationship: 10 μm ≤ A ≤ 100 μm.

[0014] In some embodiments, the first protective layer, the second protective layer, and the lithium supplement layer are integrally formed by stamping.

[0015] The energy storage battery according to an embodiment of the present invention includes: the protective film for packaging the battery cell as described above.

[0016] Due to using the protective film as shown above to package the outside of the battery cell in the energy storage battery according to an embodiment of the present invention, when the lithium ions in the battery solution are insufficient, the lithium ions in the lithium supplement layer can be dissipated and enter the battery solution through the release channels, so as to supplement the lithium ion concentration in the battery solution, so that the lithium ions in the battery solution can maintain a relatively high concentration, and the battery solution has better energy storage capacity, thereby improving the service performance and service life of the battery.

[0017] The additional aspects and advantages of the present invention will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present invention. Description of the Drawings

[0018] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

[0019] Figure 1 is a schematic structural diagram of the protective film according to an embodiment of the present invention;

[0020] Reference Signs:

[0021] Protective film 10,

[0022] First protective layer 100,

[0023] Lithium replenishing layer 200, lithium replenishing agent 210, binder 220,

[0024] The second protection layer 300 and the release channel 310 . DETAILED DESCRIPTION

[0025] The embodiments of the present utility model are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. The embodiments of the present utility model are described in detail below.

[0026] Reference below Figure 1 A protective film 10 for packaging a battery cell according to an embodiment of the present utility model is described, comprising: a first protective layer 100, a lithium supplement layer and a second protective layer 300.

[0027] Specifically, the lithium replenishing layer is arranged on one side of the first protective layer 100, and the lithium replenishing layer can release lithium ions; the second protective layer 300 is arranged on the side of the lithium replenishing layer away from the first protective layer 100, and a release channel 310 is provided on the second protective layer 300, and lithium ions can enter the battery solution through the release channel 310.

[0028] That is to say, during the use of the battery cell, the lithium ions in the battery solution will decrease with the increase of usage time, so that the battery's energy storage capacity and performance will decline.

[0029] Therefore, the present application provides a protective film 10 for packaging battery cells. The protective film 10 can be coated on the outside of the battery cell. When a large amount of lithium ions are lost in the battery cell, the lithium ions contained in the battery cell can be transported to the battery solution through the lithium replenishment layer to replenish the lithium ions in the battery solution, so as to improve the energy storage performance and usage performance of the battery.

[0030] Specifically, a first protective layer 100 and a second protective layer 300 are respectively provided on both sides of the lithium replenishment layer. The first protective layer 100 and the second protective layer 300 are suitable for protecting the lithium replenishment layer to prevent unnecessary escape of lithium ions in the lithium replenishment layer, so as to reduce the lithium ion replenishment effect of the lithium replenishment layer on the battery solution. In order to allow the lithium ions in the lithium replenishment layer to enter the battery solution as designed, a release channel 310 is provided on the second protective layer 300 in the lithium replenishment layer facing the battery solution, and the lithium ions in the lithium replenishment layer can enter the battery solution through the release channel 310 as designed to achieve the replenishment of lithium ions in the battery solution.

[0031] According to the protective film 10 for packaging an electric core in an embodiment of the present utility model, by disposing the protective film 10 outside the electric core, the lithium supplement layer in the middle of the protective film 10 can dissipate lithium ions in the lithium supplement layer when lithium ions in the battery solution are insufficient, and enter the battery solution through the release channel 310, so as to supplement the lithium ion concentration in the battery solution, so that the lithium ions in the battery solution can maintain a relatively high concentration, so that the battery solution has better energy storage capacity, and the service performance and service life of the battery are improved.

[0032] In some embodiments, the lithium supplement layer includes: a lithium supplement agent 210 and a binder 220, and the lithium supplement agent 210 and the binder 220 are uniformly mixed. It can be understood that, in order to more reliably dispose the lithium supplement layer between the first protective layer 100 and the second protective layer 300, it is suitable to mix a binder 220 in the lithium supplement layer to improve the setting stability of the lithium supplement layer. At the same time, a lithium supplement agent 210 is also incorporated in the lithium supplement layer. There are lithium ions in the lithium supplement agent 210, and the lithium ions in the lithium supplement agent 210 can be supplemented into the battery solution according to requirements.

[0033] In some embodiments, the proportion of the lithium supplement agent 210 in the lithium supplement layer is α, and the proportion α satisfies the relational expression: α≥70%. In this way, in order to enable a sufficient amount of lithium ions in the lithium supplement layer to enter the battery solution, it is suitable to make the setting content of the lithium supplement agent 210 in the lithium supplement layer greater than 70%. At the same time, the proportion of the binder 220 is less than 30%, so that the binder 220 can be more reliably adhered between the first protective layer 100 and the second protective layer 300, and reduce or even avoid affecting the transport of lithium ions in the lithium supplement layer, so that the protective film 10 has high lithium supplement performance, thereby improving the service performance of the electric core protected by the protective film 10. In some specific embodiments, the range of α is between 70% and 95%.

[0034] In some embodiments, the release channel 310 is a plurality of through holes arranged at intervals. It can be understood that by setting the release channel 310 as a plurality of through holes arranged at intervals, the lithium ions in the lithium supplement layer can enter the battery solution according to the design to supplement the lithium ions in the battery solution, improving the service performance of the battery solution. And by arranging the through holes at intervals, the lithium ions can supplement the battery solution faster and more evenly, improving the supplement efficiency of lithium ions in the battery. In some specific embodiments, the shapes of the through holes include but are not limited to circular, elliptical, triangular, square, etc.

[0035] In some embodiments, the total area of the release channel 310 is A, and the longitudinal cross-sectional area of the second protective layer 300 is B. The total area A and the cross-sectional area B satisfy the relationship: 10%B ≤ A ≤ 50%B. In this way, by setting the total area of the release channel 310 to be between 10% and 50% of the outer surface area of the second protective layer 300, not only can lithium ions enter the battery solution better to supplement the performance of the battery solution, but also the over-fast replenishment of the lithium supplement layer can be avoided, which affects the use of the battery solution, so that the protective film 10 has high performance.

[0036] In some embodiments, the thickness of the first protective layer 100 is C, and the thickness of the second protective layer 300 is D. The thickness C and the thickness D satisfy the relationship: 50um ≤ C ≤ 150um, 50um ≤ D ≤ 150um. It should be noted that the thicknesses of the first protective layer 100 and the second protective layer 300 should not be too thick or too thin. If they are too thin, the protective capabilities of the first protective layer 100 and the second protective layer 300 for the lithium supplement layer will be affected. If they are too thick, unnecessary production costs will be increased. Therefore, it is suitable to set the thicknesses of the first protective layer 100 and the second protective layer 300 between 50um and 150um to balance the protective ability and production cost.

[0037] In some embodiments, both the first protective layer 100 and the second protective layer 300 are polypropylene (PP) films. In this way, by setting the first protective layer 100 and the second protective layer 300 as polypropylene films, the first protective layer 100 and the second protective layer 300 have the characteristics of being non-toxic, odorless, low density, high heat resistance, non-water-absorbing, and good electrical insulation, so as to protect the battery disposed therein, avoid battery leakage, and improve the use safety of the battery.

[0038] In some embodiments, the thickness of the lithium supplement layer is E, and the thickness E satisfies the relationship: 10um ≤ A ≤ 100um. In this way, the thickness of the lithium supplement layer should not be too large or too small. If the thickness of the lithium supplement layer is too low, the lithium supplement performance of the lithium supplement layer will be relatively poor. If the lithium supplement layer is too thick, the lithium ions in the lithium supplement layer cannot be completely supplemented into the battery solution, affecting the supplementary effect of the protective film 10 on the battery accommodation. Therefore, by setting the thickness of the lithium supplement layer between 10um and 100um, not only does the lithium supplement layer have high lithium supplement ability, but also the lithium supplement layer can supplement lithium ions into the battery solution better to improve the performance of the battery solution.

[0039] In some embodiments, the first protective layer 100, the second protective layer 300, and the lithium supplement layer are integrally formed by stamping. It can be understood that by integrally forming the first protective layer 100, the second protective layer 300, and the lithium supplement layer by stamping, the production steps of the protective film 10 can be saved, the production process of the protective film 10 can be simplified, and the connection strength of the protective film 10 can be improved, so that the performance of the protective film 10 is improved.

[0040] The energy storage battery according to an embodiment of the present utility model includes: the protective film 10 for packaging the battery cells as described above.

[0041] It should be noted that the lithium supplementing agent 210 mainly includes but is not limited to LiPF6, LiFSI, inert lithium powder, etc. The binder mainly includes but is not limited to materials such as PMMA, SBR, PVDF, and PTFE.

[0042] In this way, since the protective film 10 as shown above is used to package the outside of the battery cells in the energy storage battery, when the lithium ions in the battery solution are insufficient, the lithium ions in the lithium supplementing layer in the middle of the protective film 10 can be dissipated, and enter the battery solution through the release channel 310 to supplement the lithium ion concentration in the battery solution, so that the lithium ions in the battery solution can maintain a relatively high concentration, so that the battery solution has better energy storage capacity, and the service performance and service life of the battery are improved.

[0043] Other components and operations of the energy storage battery according to an embodiment of the present utility model are known to those of ordinary skill in the art and will not be described in detail here.

[0044] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example.

[0045] Although the embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirits of the present utility model, and the scope of the present utility model is defined by the claims and their equivalents.

Claims

1. A protective film for packaging a battery cell, characterized in that: include: First protective layer; A lithium replenishing layer, the lithium replenishing layer is arranged on one side of the first protective layer, and the lithium replenishing layer can release lithium ions; The second protective layer is arranged on the side of the lithium supplement layer away from the first protective layer, and a release channel is arranged on the second protective layer, and the lithium ions can enter the battery solution through the release channel.

2. The protective film for packaging battery cells according to claim 1, characterized in that: The lithium supplement layer comprises: a lithium supplement agent and a binder, and the lithium supplement agent and the binder are uniformly mixed.

3. The protective film for packaging battery cells according to claim 2, characterized in that: The proportion of the lithium replenishing agent in the lithium replenishing layer is α, and the proportion α satisfies the relationship: α≥70%.

4. The protective film for packaging a battery cell according to claim 1, characterized in that: The release channels are a plurality of through holes arranged at intervals.

5. The protective film for packaging battery cells according to claim 1, characterized in that: The total area of ​​the release channel is A, the longitudinal cross-sectional area of ​​the second protective layer is B, and the total area A and the cross-sectional area B satisfy the relationship: 10%B≤A≤50%B.

6. The protective film for packaging battery cells according to claim 1, characterized in that: The thickness of the first protective layer is C, the thickness of the second protective layer is D, and the thickness C and the thickness D satisfy the relationship: 50um≤C≤150um, 50um≤D≤150um.

7. The protective film for packaging battery cells according to claim 1, characterized in that: The first protective layer and the second protective layer are both poly PP films.

8. The protective film for packaging battery cells according to claim 1, characterized in that: The thickness of the lithium replenishing layer is E, and the thickness E satisfies the relationship: 10um≤A≤100um.

9. The protective film for packaging battery cells according to claim 1, characterized in that: The first protective layer, the second protective layer and the lithium supplement layer are integrally stamped and formed.

10. An energy storage battery, characterized in that: include: A protective film for packaging a battery cell as claimed in any one of claims 1 to 9.

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