Pole piece, battery cell and battery
By designing a second active material section with larger pores in the electrode, the problems of electrolyte wetting and lithium-ion transport caused by the increase of active material are solved, thereby improving battery processing efficiency, extending cycle life, and enhancing charge and discharge performance.
Patent Information
- Application Number
- CN202423263316.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2026-02-13
- Estimated Expiration
- 2034-12-27
AI Technical Summary
In existing technologies, in order to increase battery capacity, the amount of active material is increased, which leads to an increase in electrode thickness, affecting electrolyte wetting and lithium-ion transport, resulting in an increase in battery volume and a decrease in charge and discharge performance.
The electrode structure is designed to include a first active material section and a second active material section. The second active material section is located inside the receiving hole and has a compaction density lower than that of the first active material section. By processing the receiving hole on the current collector and filling it with loose active material, a second active material section with larger pores is formed, thereby improving electrolyte permeability and lithium-ion transport efficiency.
Shortening electrolyte immersion time improves battery processing efficiency, reduces polarization, extends battery cycle life, enhances lithium-ion transport pathways, and improves charge/discharge efficiency and battery safety.
Smart Images
Figure CN223911628U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to battery technology field especially relates to a pole piece, electric core and battery. BACKGROUND
[0002] People pursue higher endurance capacity for mobile phones, notebook computers and other 3C electronic products, and the battery is the key to endurance, and in some technologies, more active substances are coated on the foil surface to improve the capacity of the battery, but more active substances will increase the thickness of the pole piece, resulting in the increase of the volume of the battery. In order to solve this problem, in some technologies, the thickness of the pole piece is reduced by pressing the active substance more solid, however, too solid active substance will lead to the difficulty of electrolyte infiltration. SUMMARY
[0003] The utility model aims at at least solves one of the technical problems existing in prior art. For this reason, the utility model provides a pole piece, which can be used for battery to shorten the electrolyte infiltration time, thereby improving the processing efficiency of the battery.
[0004] The utility model further provides an electric core comprising the pole piece.
[0005] The utility model further provides a battery comprising the electric core.
[0006] According to the pole piece of the first aspect embodiment of the utility model, the pole piece comprises a current collector and an active substance layer.
[0007] The pole piece has a set thickness, the current collector has a first surface and a second surface arranged opposite along the thickness direction of the pole piece, at least one of the first surface and the second surface is provided with the active substance layer, the active substance layer comprises a first active substance part and a second active substance part, the first active substance part is arranged on the current collector, the first active substance part has a containing hole extending along the thickness direction of the pole piece, the second active substance part is located in the containing hole, the compaction density of the first active substance part is D1, the compaction density of the second active substance part is D2, and D2
[0008] According to the pole piece of the utility model embodiment, at least has the following beneficial effects:
[0009] In the present embodiment, the active material layer includes a first active material portion and a second active material portion, wherein the first active material portion has a receiving hole, the second active material is located in the receiving hole, and the second active material portion has a smaller compaction density than the first active material portion. That is, the porosity in the second active material portion is greater than the porosity in the first active material portion, so that when the electrode sheet of the present embodiment is used in a battery, the electrolyte can quickly penetrate into the active material, so as to shorten the electrolyte impregnation time, thereby improving the processing efficiency of the battery. In addition, sufficient impregnation of the electrolyte in the active material can reduce the polarization phenomenon caused by uneven impregnation, reduce the performance degradation of the battery during the cycle process, thereby prolonging the cycle life of the battery.
[0010] According to some embodiments of the present application, the first surface and the second surface are both provided with the active material layer.
[0011] According to some embodiments of the present application, the current collector further has a plurality of connecting holes penetrating the first surface and the second surface.
[0012] According to some embodiments of the present application, part of the active material layer is located in the connecting hole.
[0013] According to some embodiments of the present application, the active material layer located on the first surface is a first active material layer, the receiving hole located inside the first active material layer is a first receiving hole, the active material layer located on the second surface is a second active material layer, the receiving hole located on the second active material layer is a second receiving hole, the first receiving hole, the connecting hole and the second receiving hole are in communication with each other, and part of the second active material portion is located in the connecting hole.
[0014] According to some embodiments of the present application, the electrode sheet has a set width and a set length, the current collector has a plurality of rows of connecting holes distributed along the width direction of the electrode sheet, each row of connecting holes includes a plurality of connecting holes spaced apart along the length direction of the electrode sheet, and adjacent rows of connecting holes are arranged staggered in the width direction of the electrode sheet.
[0015] According to some embodiments of the present application, the surface of the first active material portion away from the current collector is a third surface, and along the thickness direction of the current collector, the distance between the hole opening of the receiving hole away from the current collector and the third surface is L, L>0.
[0016] According to some embodiments of the present application, the surface of the active material layer away from the current collector is a third surface, the area of the third surface is S1, the sum of the areas of the cross sections of each receiving hole parallel to the first surface is S2, and 0.1%≤S2 / S1≤10%.
[0017] According to some embodiments of the present application, the compaction density of the first active material part ranges from 1 g / cm 3 to 2.5 g / cm 3 , and the compaction density of the second active material part ranges from 0.8 g / cm 3 to 2.3 g / cm 3 .
[0018] The battery cell according to the second aspect of the present application comprises the electrode tab according to the first aspect of the present application.
[0019] The battery cell according to the present application has at least the following beneficial effects:
[0020] The electrode tab according to the first aspect of the present application has an active material layer comprising a first active material part and a second active material part, wherein the first active material part has a receiving hole, the second active material is located in the receiving hole, and the compaction density of the second active material part is less than that of the first active material part. That is, the porosity in the second active material part is greater than that in the first active material part. Thus, when the battery cell according to the present application is used in a battery, the electrolyte can quickly penetrate into the active material, so as to shorten the electrolyte soaking time, thereby improving the processing efficiency of the battery. In addition, the sufficient soaking of the electrolyte in the active material can reduce the polarization phenomenon caused by uneven soaking, reduce the performance degradation of the battery in the cycle process, thereby prolonging the cycle life of the battery. Thus, when the battery according to the present application is used in an electrical equipment, the service life of the electrical equipment can be prolonged.
[0021] The battery according to the third aspect of the present application comprises the battery cell according to the first aspect of the present application.
[0022] The battery according to the present application has at least the following beneficial effects:
[0023] The battery cell according to the second aspect of the present application has an electrode tab with an active material layer comprising a first active material part and a second active material part, wherein the first active material part has a receiving hole, the second active material is located in the receiving hole, and the compaction density of the second active material part is less than that of the first active material part. That is, the porosity in the second active material part is greater than that in the first active material part. Thus, the electrolyte can quickly penetrate into the active material, so as to shorten the electrolyte soaking time, thereby improving the processing efficiency of the battery. In addition, the sufficient soaking of the electrolyte in the active material can reduce the polarization phenomenon caused by uneven soaking, reduce the performance degradation of the battery in the cycle process, thereby prolonging the cycle life of the battery.
[0024] The additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter in the description of the application. BRIEF DESCRIPTION OF DRAWINGS
[0025] The present application will be further described below in conjunction with the drawings and embodiments, wherein:
[0026] Figure 1 is a sectional view of the first kind of pole piece of the first aspect embodiment of the present application;
[0027] Figure 2 is a sectional view of the second kind of pole piece of the first aspect embodiment of the present application;
[0028] Figure 3 is a sectional view of the third kind of pole piece of the first aspect embodiment of the present application;
[0029] Figure 4 is a structural schematic view of the fourth kind of pole piece of the first aspect embodiment of the present application.
[0030] Figure 5 is a sectional view of the fifth kind of pole piece of the first aspect embodiment of the present application.
[0031] REFERENCE NUMERALS:
[0032] current collector 100, first surface 110, second surface 120, connecting hole 130;
[0033] active material layer 200, first active material layer 201, first accommodating hole 2011, second active material layer 202, second accommodating hole 2021, first active material part 210, accommodating hole 211, hole opening 2111, third surface 212, second active material part 220. DETAILED DESCRIPTION
[0034] The embodiments of the present application will be described in detail below, examples of which are shown in the drawings, wherein the same or similar numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary, only for explaining the present application, and cannot be understood as a limitation of the present application.
[0035] In the description of the present application, it is understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or position relationship shown in the drawings, only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as a limitation of the present application.
[0036] In the description of the utility model, if the meaning of several is more than one, the meaning of multiple is more than two, greater than, less than, more than, etc. Understand as not including the number, above, below, within, etc. Understand as including the number. If it is described to the first, the second is only used for distinguishing the purpose of technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features.
[0037] In the description of the utility model, unless otherwise explicitly limited, the words such as setting, installation, connection should be understood in a broad sense, and the person skilled in the art can reasonably determine the specific meaning of the above words in the utility model according to the specific content of the technical scheme.
[0038] People pursue higher endurance for mobile phones, notebook computers and other 3C electronic products, and the battery is the key to endurance. In order to improve the capacity of the battery, more active substances are coated on the surface of the foil in some technologies, but more active substances will increase the thickness of the pole piece, which will lead to the increase of the volume of the battery. In order to solve this problem, in some technologies, the thickness of the pole piece is reduced by pressing the active substance more solidly, however, the active substance pressed too solidly will affect the electrolyte penetration and lithium ion transmission, which will lead to the decline of the battery charge and discharge performance.
[0039] In view of the above background, the utility model provides a pole piece which can be used for a battery to shorten the electrolyte infiltration time in the battery processing process, thereby improving the processing efficiency of the battery. The battery is, for example, a lithium battery or a lead-acid battery, and the utility model takes the lithium battery as an example for description, unless otherwise specified. Refer to Figure 1 , Figure 1 It is the sectional view of the first pole piece of the first aspect embodiment of the utility model, the pole piece of the embodiment is, for example, an anode pole piece or a cathode pole piece, and the pole piece comprises: a current collector 100 and an active material layer 200.
[0040] The pole piece has a set thickness, and the current collector 100 has a first surface 110 and a second surface 120 arranged opposite to each other along the thickness direction of the pole piece. The active material layer 200 is arranged on the first surface 110 or the second surface 120, or both the first surface 110 and the second surface 120 are provided with the active material layer 200. The active material layer 200 includes a first active material part 210 and a second active material part 220, the first active material part 210 is arranged on the current collector 100, the first active material part 210 has a receiving hole 211 extending along the thickness direction of the pole piece, and the second active material part 220 is located in the receiving hole 211. The first active material part 210 has a compaction density D1, the second active material part 220 has a compaction density D2, and D2 < D1. The compaction density of the first active material part 210 is, for example, 1 g / cm3 to 2.5 g / cm3, and the compaction density of the second active material part 220 is, for example, 0.8 g / cm3 to 2.3 g / cm3.
[0041] In the processing process, the active material is first coated on the surface (the first surface 110 or the second surface 120) of the current collector 100, and the active material is compacted, and then the receiving hole 211 is processed on the coated active material by mechanical processing or laser, etc. to form the first active material part 210, and finally the device is used to fill the second active material part 220 in the receiving hole 211. Alternatively, the first layer of active material can be first coated on the surface of the current collector 100, and the first layer of active material is compacted, and then the hole is dug on the first layer of active material, and then the second layer of active material is coated on the surface of the first layer of active material, and the second layer of active material is compacted. Due to the existence of the hole dug on the first layer of active material, the second layer of active material will collapse and become more loose at the hole, so that the compaction density of the active material at the hole is reduced to form the second active material part 220.
[0042] Specifically, in the embodiment, the active material layer 200 includes a first active material part 210 and a second active material part 220, wherein the first active material part 210 has a containing hole 211, the second active material is located in the containing hole 211, and the compaction density of the second active material part 220 is less than the compaction density of the first active material part 210. That is, the porosity in the second active material part 220 is greater than the porosity in the first active material part 210, thereby, when the pole piece of the embodiment is used in a battery, the electrolyte can be quickly infiltrated into the active material, so as to shorten the electrolyte infiltration time, thereby improving the processing efficiency of the battery. In addition, the electrolyte is quickly infiltrated into the active material layer 200, which can ensure that, during the charging process, lithium ions are released from the positive electrode, quickly migrate to the negative electrode through the electrolyte and are embedded in the negative electrode material, and correspondingly, during the discharging process, the lithium ions can quickly migrate from the negative electrode to the positive electrode. Such an efficient lithium ion transmission path can reduce the polarization phenomenon, thereby improving the charging and discharging efficiency of the battery. In addition, it can be understood that, during the charging and discharging process of the battery, the active material (specifically, the active material layer 200 in the embodiment) often expands or shrinks in volume, causing instability of the interface structure. After the electrolyte is quickly infiltrated into the active material layer 200, a stable protective film can be formed to prevent the active material from being directly exposed to the electrolyte, thereby slowing down the destruction of the interface structure and prolonging the cycle life of the battery.
[0043] With reference to Figure 2 , Figure 2 is a sectional view of the second pole piece of the first aspect of the utility model, in some embodiments, the current collector 100 also has a plurality of connecting holes 130, the connecting holes 130 pass through the first surface 110 and the second surface 120. Specifically, when the connecting holes 130 are provided in the current collector 100, the migration of lithium ions is diffused through the two-dimensional direction of the current collector 100 to the tab end, after the connecting holes 130 are provided in the current collector 100, the diffusion path of lithium ions can be converted into a three-dimensional all-around penetration, thereby improving the lithium ion transmission efficiency. In addition, the active material located between the connecting holes 130 can increase the contact surface of the active material and the current collector 100, and reduce the lithium ion migration radius, thereby further improving the charging and discharging efficiency of the battery. In addition, when the active material layer 200 is provided, part of the material of the active material layer 200 can be embedded into the connecting holes 130, so that the active material layer 200 and the current collector 100 form a clamping state, thereby increasing the connection strength between the active material layer 200 and the current collector 100, and reducing the risk of falling off of the active material layer 200.
[0044] With reference to Figure 3 , Figure 3For the third cross section view of the pole piece of the first aspect of the utility model, on the basis of the above embodiment, the active material layer 200 located at the first surface 110 is a first active material layer 201, the accommodating hole 211 located inside the first active material layer 201 is a first accommodating hole 2011, the active material layer 200 located at the second surface 120 is a second active material layer 202, the accommodating hole 211 located at the second active material layer 202 is a second accommodating hole 2021, the first accommodating hole 2011, the connecting hole 130 and the second accommodating hole 2021 are in communication with each other, and part of the second active material part 220 is located inside the connecting hole 130, that is, the connecting hole 130 corresponds to the second active material part 220 with a smaller compactness. Therefore, after lithium ions move to the connecting hole 130, they can quickly move inside the second active material part 220, and the charging and discharging efficiency of the battery can be further improved.
[0045] In addition, the connecting hole 130 communicates the first accommodating hole 2011 and the second accommodating hole 2021, and can also make the processing of the pole piece simpler to reduce the processing cost of the pole piece. Exemplarily, in the processing process, the active material is coated on the first surface 110 and the second surface 120 of the current collector 100 to form a semi-finished product, and a through hole 400 or a blind hole extending in the thickness direction is processed on the semi-finished product to form the first accommodating hole 2011 of the first active material layer 201, the second accommodating hole 2021 of the second active material layer 202 and the connecting hole 130 of the current collector 100, and then the active material with a looser compactness is filled in the through hole 400 or the blind hole to form the second active material part 220 with a lower compactness. Alternatively, the active material is coated on the first surface 110 to form a semi-finished product, and a through hole 400 or a blind hole is processed on the semi-finished product to form the first accommodating hole 2011 of the first active material part 210 and the connecting hole 130 of the current collector 100, and then the active material is coated on the second surface 120. During the coating process, the active material will automatically enter the connecting hole 130 and the first accommodating hole 2011, and the compactness of the active material located at the connecting hole 130 is reduced to form the second active material part 220 with a smaller compactness, so that the processing of the pole piece is simpler.
[0046] Referring to Figure 4 , Figure 4As shown in the structure schematic view of the fourth kind of pole piece and current collector of the first aspect of the utility model, in some embodiments, the pole piece has a set width and a set length, the current collector 100 has multiple rows of connecting holes 130 distributed along the width direction of the pole piece, each row of connecting holes 130 includes multiple connecting holes 130 spaced along the length direction of the pole piece, and adjacent rows of connecting holes 130 are arranged staggeredly in the width direction of the pole piece. Specifically, the regularly arranged connecting holes 130 can cause stress to concentrate in some areas of the current collector 100, thereby increasing the risk of breaking the pole piece during winding. The staggered arrangement of the connecting holes 130 can more evenly disperse stress in the entire current collector 100, can increase the mechanical strength and stability of the pole piece, and can reduce the risk of breaking the pole piece during winding, thereby improving the yield rate during battery processing. In addition, as known from the above embodiment, the connecting hole 130 is communicated with the first accommodating hole 2011 and the second accommodating hole 2021, the connecting hole 130 is arranged staggeredly, that is, the first accommodating hole 2011 on the first active material layer 201 is arranged staggeredly, and the second accommodating hole 2021 on the second active material is arranged staggeredly, so as to improve the current distribution of the pole piece and improve the performance and safety of the battery.
[0047] With reference to Figure 5 , Figure 5 As shown in the sectional view of the fifth kind of pole piece of the first aspect of the utility model, in some embodiments, the surface of the first active material part 210 away from the current collector 100 is a third surface 212, along the thickness direction of the current collector 100, the distance between the hole opening 2111 of the accommodating hole 211 away from the current collector 100 and the third surface 212 is L, and L>0. Specifically, it can be known that in the battery, the active material is pressed more solidly, the substances are more strongly connected with each other and are not easy to fall off. Based on this, in the present embodiment, the accommodating hole 211 is located inside the first active material part 210, that is, the second active material part 220 with a lower compaction density is located inside the first active material part with a higher compaction density, thereby reducing the risk of falling off of the active material and further improving the performance of the battery.
[0048] In some embodiments, the first surface 110 has an area S1, the sum of the areas of the cross sections of the connection holes 130 parallel to the first surface 110 is S2, and 0.01%≤S2 / S1≤10%. Specifically, it can be known that the greater the proportion of the connection holes 130, the lower the strength of the current collector 100, and the smaller the contact area between the active material layer 200 and the current collector 100, which means that less active material can participate in the charging and discharging process of the battery, thereby reducing the capacity and energy density of the battery. Based on this, in the present embodiment, the proportion of the connection holes 130 is set within a suitable range, i.e. 0.01%≤S2 / S1≤10%, so that when the tab of the present embodiment is used in a battery, the battery can have a higher energy density and capacity under the premise of improving the charging and discharging efficiency of the battery.
[0049] The second aspect embodiment of the utility model discloses a battery cell, including the tab of the first aspect embodiment, and the tab is for example the anode tab and / or cathode tab. Taking a lithium ion battery as an example, when being the anode tab, the current collector 100 is for example copper foil, and the active material is for example graphite. When being the cathode tab, the current collector 100 is for example aluminum foil, and the active material layer 200 is for example lithium ion compound such as lithium cobaltate (LiCoO2), lithium manganate (LiMnO4) or lithium iron phosphate (LiFePO4). The active material layer 200 of the tab includes the first active material part 210 and the second active material part 220, wherein the first active material part 210 has the accommodation hole 211, the second active material part 220 is located in the accommodation hole 211, and the compaction density of the second active material part 220 is less than the compaction density of the first active material part 210. That is, the porosity in the second active material part 220 is greater than the porosity in the first active material part 210, so that when the tab of the present embodiment is used in a battery, the electrolyte can quickly penetrate into the active material, so as to shorten the electrolyte soaking time, thereby improving the processing efficiency of the battery. In addition, the electrolyte fully soaking the active material can reduce the polarization phenomenon caused by uneven soaking, reduce the performance degradation of the battery in the cycle process, thereby prolonging the cycle life of the battery.
[0050] It should be noted that since the present embodiment adopts all the technical features of the first aspect embodiment, the present embodiment has all the beneficial effects brought by the first aspect embodiment, which will not be repeated here.
[0051] The battery of the third aspect embodiment, for example, is a soft package battery, or a hard shell battery such as a steel shell battery, an aluminum shell battery, etc., and comprises the battery cell of the second aspect embodiment. The active material layer 200 of the pole piece of the battery cell comprises a first active material portion 210 and a second active material portion 220, wherein the first active material portion 210 has a containing hole 211, the second active material portion 220 is located in the containing hole 211, and the second active material portion 220 has a smaller compaction density than the first active material portion 210. That is, the porosity in the second active material portion 220 is greater than the porosity in the first active material portion 210, so that the electrolyte can quickly penetrate into the active material, thereby shortening the electrolyte soaking time and improving the processing efficiency of the battery. In addition, sufficient electrolyte soaking in the active material can reduce the polarization phenomenon caused by uneven soaking, reduce the performance degradation of the battery during the cycle process, and thus prolong the cycle life of the battery. Therefore, when the battery of the embodiment is used in an electrical equipment, the service life of the electrical equipment can be prolonged.
[0052] The embodiments of the utility model are described in detail above in combination with the drawings, but the utility model is not limited to the above-mentioned embodiments, and various changes can be made within the knowledge range possessed by the ordinary skilled in the art without departing from the purpose of the utility model. In addition, in the description of the utility model, the description of the reference terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are contained in at least one embodiment or example of the utility model. In the specification, the illustrative description of the above-mentioned terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.
Claims
1. A pole piece characterized by, The positive plate includes: a current collector having a first surface and a second surface oppositely arranged along a thickness direction of the positive plate an active material layer arranged on at least one of the first surface and the second surface, the active material layer including a first active material portion and a second active material portion, the first active material portion being arranged on the current collector, the first active material portion having a receiving hole extending along the thickness direction of the positive plate, the second active material portion being located in the receiving hole, the first active material portion having a first compact density D1 and the second active material portion having a second compact density D2, D2 < D1.
2. The pole piece of claim 1, wherein The first surface and the second surface are both provided with the active material layer.
3. The pole piece of claim 2, wherein The current collector further has a plurality of connecting holes penetrating the first surface and the second surface.
4. The pole piece of claim 3, wherein The active material layer located on the first surface is a first active material layer, the receiving hole located inside the first active material layer is a first receiving hole, the active material layer located on the second surface is a second active material layer, the receiving hole located in the second active material layer is a second receiving hole, the first receiving hole, the connecting hole and the second receiving hole are in communication with each other, and part of the second active material portion is located in the connecting hole.
5. The pole piece of claim 3, wherein The positive plate has a set width and a set length, the current collector has a plurality of rows of the connecting holes distributed along the width direction of the positive plate, each row of the connecting holes includes a plurality of the connecting holes spaced apart along the length direction of the positive plate, and adjacent rows of the connecting holes are arranged staggered in the width direction of the positive plate.
6. The pole piece of claim 1, wherein A surface of the first active material portion facing away from the current collector is a third surface, and along the thickness direction of the current collector, a distance between an aperture of the receiving hole facing away from the current collector and the third surface is L, L > 0.
7. The pole piece of claim 3, wherein An area of the first surface is S1, a total area of cross sections of the connecting holes parallel to the first surface is S2, and 0.1% ≤ S2 / S1 ≤ 10%.
8. The pole piece of claim 1, wherein The first active material section has a compaction density in the range of 1 g / cm 3 to 2.5 g / cm 3 . The second active material section has a compaction density in the range of 0.8 g / cm 3 to 2.3 g / cm 3 .
9. An electric cell, characterized by The positive plate includes:
10. A battery characterized by The battery cell includes: