A battery

Abstract

In order to overcome the problems of high manufacturing cost and insufficient energy density of existing secondary batteries, the present invention provides a battery, including a first pole piece, a second pole piece and a pole core, wherein the pole core is located between the first pole piece and the second pole piece, and the first pole piece and the second pole piece are surrounded to form a battery shell for accommodating the pole core; the inner side of the first pole piece is covered with a first active material layer, and a first barrier layer is provided between the first active material layer and the pole core; the inner side of the second pole piece is covered with a second active material layer, and a second barrier layer is provided between the second active material layer and the pole core; the first pole piece and the second pole piece and the pole core together form a primary battery structure. The battery provided by the present invention effectively improves the space utilization rate of the battery, reduces the preparation cost, and improves the energy density of the battery from a structural perspective.

Description

Technical Field

[0001] The invention belongs to the technical field of energy storage electronic components, and in particular relates to a battery. Background Art

[0002] As people's living standards improve, the demand for secondary batteries is gradually increasing. Since secondary batteries can be recharged and used repeatedly, they are more environmentally friendly, but secondary batteries are insufficient in energy density compared to fuels. Therefore, developers have put forward higher requirements for the energy density of secondary batteries. At the same time, the high production cost of secondary batteries is also a factor that restricts the promotion and application of secondary batteries. The development of new production technologies is the key to solving the above problems. In the prior art, in order to reduce manufacturing costs, many components of batteries are taking the "thinning" route, such as copper foil from 8um to 6um, diaphragm from 15um to 6um, aluminum shell from 0.8mm to 0.3mm, and so on. However, the above paths to reduce the cost of battery cells through thinning materials have basically reached their limits and cannot be further broken through in the short term. The development of new materials requires a long development cycle, which is difficult to meet the needs of existing secondary batteries. Summary of the invention

[0003] Aiming at the problems of high manufacturing cost and insufficient energy density of existing secondary batteries, the present invention provides a battery.

[0004] The technical solution adopted by the present invention to solve the above technical problems is as follows:

[0005] The present invention provides a battery, comprising a first pole piece, a second pole piece and a pole core, wherein the pole core is located between the first pole piece and the second pole piece, and the first pole piece and the second pole piece are surrounded to form a battery housing for accommodating the pole core;

[0006] A first active material layer is disposed on the inner side of the first pole piece, and a first barrier layer is disposed between the first active material layer and the pole core; a second active material layer is disposed on the inner side of the second pole piece, and a second barrier layer is disposed between the second active material layer and the pole core;

[0007] The pole core includes a plurality of stacked positive pole sheets, a third barrier layer and a negative pole sheet, and the outermost layers on both sides of the pole core are positive pole sheets or negative pole sheets, the polarity of the first pole sheet and the polarity of the second pole sheet are positive or negative, and the polarity of the outermost layers on both sides of the pole core is opposite to the first pole sheet or the second pole sheet facing it.

[0008] Optionally, the polarity of the first pole piece and the polarity of the second pole piece are both positive or both negative;

[0009] When the polarity of the first pole piece and the polarity of the second pole piece are both negative poles, the outermost layers on both sides of the pole core are both positive pole pieces, the first active material layer and the second active material layer are negative active material layers, the negative pole piece is electrically connected to the first pole piece and the second pole piece, and the positive pole pieces are electrically connected to each other and lead out of the battery housing;

[0010] When the polarity of the first electrode sheet and the polarity of the second electrode sheet are both positive, the outermost layers on both sides of the electrode core are both negative electrode sheets, the first active material layer and the second active material layer are positive electrode active material layers, the positive electrode sheet is electrically connected to the first electrode sheet and the second electrode sheet, and the negative electrode sheets are electrically connected to each other and led out of the battery casing.

[0011] Optionally, the positive electrode sheet comprises a positive electrode current collector and a positive electrode material layer, the positive electrode material layer covers the two surfaces of the positive electrode current collector, one end of the positive electrode current collector is formed with a positive electrode blank area not covered by the positive electrode material layer, and a plurality of positive electrode blank areas are stacked on each other;

[0012] The negative electrode sheet comprises a negative electrode current collector and a negative electrode material layer, wherein the negative electrode material layer covers the two surfaces of the negative electrode current collector, and a negative electrode blank area not covered by the negative electrode material layer is formed at one end of the negative electrode current collector, and a plurality of negative electrode blank areas are stacked on each other;

[0013] The negative electrode blank area and the positive electrode blank area are respectively located at two ends of the pole core facing different directions.

[0014] Optionally, when the polarity of the first pole piece and the polarity of the second pole piece are both positive, one end of the first pole piece, one end of the second pole piece and the multiple positive blank areas are stacked on top of each other and tightly connected, and the first pole piece and the two sides of the second pole piece are tightly connected; the multiple negative blank areas are led out from between the other end of the first pole piece and the other end of the second pole piece, and the negative blank areas are insulated from the first pole piece and the second pole piece and tightly connected.

[0015] Optionally, a first insulating layer is provided on the inner side of the other end of the first pole piece, a second insulating layer is provided on the inner side of the other end of the second pole piece, a first insulating glue is provided on the negative electrode blank area, and the first pole piece and the second pole piece are sealed with the negative electrode blank area by hot pressing through the first insulating glue;

[0016] A plurality of negative electrode blank areas are stacked on each other and led out from between the other end of the first electrode piece and the other end of the second electrode piece;

[0017] Alternatively, a plurality of negative electrode blank areas are respectively led out from between the other end of the first electrode sheet and the other end of the second electrode sheet and then stacked on top of each other.

[0018] Optionally, when the polarity of the first pole piece and the polarity of the second pole piece are both negative, one end of the first pole piece, one end of the second pole piece and the multiple negative pole blank areas are stacked on top of each other and tightly connected, and the two sides of the first pole piece and the second pole piece are tightly connected; the multiple positive pole blank areas are led out from between the other end of the first pole piece and the other end of the second pole piece, and the positive pole blank areas are insulated from the first pole piece and the second pole piece and tightly connected.

[0019] Optionally, a first insulating layer is provided on the inner side of the other end of the first pole piece, a second insulating layer is provided on the inner side of the other end of the second pole piece, a second insulating glue is provided on the positive electrode blank area, and the first pole piece and the second pole piece are sealed with the positive electrode blank area by hot pressing through the second insulating glue;

[0020] A plurality of positive electrode blank areas are stacked on each other and led out from between the other end of the first electrode piece and the other end of the second electrode piece;

[0021] Alternatively, a plurality of positive electrode blank areas are respectively led out from between the other end of the first electrode piece and the other end of the second electrode piece and then stacked on top of each other.

[0022] Optionally, the first pole piece, the second pole piece, the positive electrode current collector and the negative electrode current collector are sheet structures with flat surfaces.

[0023] Optionally, the thickness of the current collector of the first pole sheet and the thickness of the current collector of the second pole sheet are greater than or equal to the thickness of the positive electrode current collector and the negative electrode current collector.

[0024] Optionally, positive electrode accommodating grooves are provided on both surfaces of the positive electrode collector, the positive electrode material layer is located in the positive electrode accommodating groove, a third insulating layer is arranged around the periphery of the positive electrode material layer, the positive electrode accommodating grooves of two adjacent positive electrode collectors are connected to form a negative electrode accommodating cavity, the negative electrode sheet and the third barrier layer are located in the negative electrode accommodating cavity, and the negative electrode blank area of ​​the negative electrode sheet is led out from the negative electrode accommodating cavity and is insulated from the positive electrode sheet.

[0025] Optionally, negative electrode accommodating grooves are provided on both surfaces of the negative electrode current collector, the negative electrode material layer is located in the negative electrode accommodating groove, a fourth insulating layer is arranged around the outer periphery of the negative electrode material layer, the negative electrode accommodating grooves of two adjacent negative electrode current collectors are connected to form a positive electrode accommodating cavity, the positive electrode sheet and the third barrier layer are located in the positive electrode accommodating cavity, and the positive electrode blank area of ​​the positive electrode sheet is led out from the positive electrode accommodating cavity and is insulated from the negative electrode sheet.

[0026] Optionally, a first groove is provided on the inner side of the first pole piece, and the first active material layer and the first barrier layer are located in the first groove; a second groove is provided on the inner side of the second pole piece, and the second active material layer and the second barrier layer are located in the second groove.

[0027] Optionally, the first barrier layer, the second barrier layer and the third barrier layer are each independently selected from a separator, a solid electrolyte or a semi-solid electrolyte.

[0028] Optionally, the first barrier layer is respectively bonded to the first active material layer and the electrode core coating, the second barrier layer is respectively bonded to the second active material layer and the electrode core coating, and the third barrier layer is respectively bonded to the positive electrode sheet and the negative electrode sheet coating.

[0029] According to the battery provided by the present invention, a first pole piece covered with a first active material layer and a second pole piece covered with a second active material layer are provided. The first pole piece and the second pole piece are combined with a pole core of an outermost exposed positive pole piece or negative pole piece to form a primary battery structure. At the same time, the first pole piece and the second pole piece are sealed to form a battery shell for accommodating the pole core. Therefore, the first pole piece and the second pole piece not only contribute to the battery capacity as the primary battery structure, but also protect the battery as a battery shell. There is no need to additionally set up a hard shell or aluminum-plastic film for packaging as in the prior art, which effectively improves the space utilization of the battery, reduces the traditional packaging structure such as the shell, reduces the preparation cost, and also effectively reduces the overall mass of the battery, making the battery space more compact, thereby improving the energy density of the battery from a structural perspective. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is an exploded view of the first embodiment of the battery provided by the present invention;

[0031] Figure 2 yes Figure 1 An assembly cross-sectional view of the battery implementation structure 1;

[0032] Figure 3 yes Figure 1 An assembly side cross-sectional view of the middle battery implementation structure 1;

[0033] Figure 4 is an exploded view of the second embodiment of the battery provided by the present invention;

[0034] Figure 5 yes Figure 4 An assembly cross-sectional view of the second battery implementation structure;

[0035] Figure 6 yes Figure 4 Front structural view of the positive electrode;

[0036] Figure 7 yes Figure 4 Side structural view of the positive electrode;

[0037] Figure 8 is an exploded view of the third embodiment of the battery provided by the present invention;

[0038] Fig. 9 yes Figure 8 The assembly cross-section diagram of the battery implementation structure three;

[0039] Fig.10 is an exploded view of a fourth embodiment of a battery provided by the present invention;

[0040] Fig.11 yes Fig.10 Assembly cross-section diagram of the battery implementation structure four.

[0041] The reference numerals in the drawings of the specification are as follows:

[0042] 1. First pole piece; 11. First insulating layer; 12. First groove; 2. Second pole piece; 21. Second insulating layer; 22. Second groove; 3. First active material layer; 4. Second active material layer; 5. First barrier layer; 6. Second barrier layer; 7. Pole core; 71. Negative pole piece; 711. Negative current collector; 7111. Negative blank area; 7112. Negative receiving groove; 712. Negative material layer; 713. First insulating glue; 714. Fourth insulating layer; 72. Positive pole piece; 721. Positive current collector; 7211. Positive blank area; 7212. Positive receiving groove; 722. Positive material layer; 723. Second insulating glue; 724. Third insulating layer; 73. Third barrier layer. DETAILED DESCRIPTION

[0043] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0044] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0045] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] See also Figures 1 to 11 As shown, an embodiment of the present invention provides a battery, including a first pole piece 1, a second pole piece 2 and a pole core 7, wherein the pole core 7 is located between the first pole piece 1 and the second pole piece 2, and the first pole piece 1 and the second pole piece 2 are combined to form a battery casing for accommodating the pole core 7.

[0047] In the description of the present invention, the term "encirclement" should be understood in a broad sense, and can be directly enclosing the edge of the first pole piece 1 and the edge of the second pole piece 2, or other structures can be provided between the edge of the first pole piece 1 and the edge of the second pole piece 2. The methods of directly enclosing the first pole piece 1 and the second pole piece 2 include: high-voltage impact integration, welding integration, or folding and hot pressing sealing. When the first pole piece 1 and the second pole piece 2 are provided with other structures: they can be connected by hot pressing with hot pressing glue, or they can be connected to each other through an intermediate piece. The intermediate piece can be the lead-out structure of the positive pole piece 72 and the negative pole piece 71, etc. When electrical connection needs to be achieved, they can be directly welded. When electrical connection is not required, they can be insulated and bonded to each other through hot pressing glue.

[0048] A first active material layer 3 is disposed on the inner side of the first pole piece 1, and a first barrier layer 5 is disposed between the first active material layer 3 and the pole core 7; a second active material layer 4 is disposed on the inner side of the second pole piece 2, and a second barrier layer 6 is disposed between the second active material layer 4 and the pole core 7;

[0049] The electrode core 7 includes a plurality of stacked positive electrode sheets 72, a third barrier layer 73 and a negative electrode sheet 71. The polarity of the first electrode sheet 1 and the polarity of the second electrode sheet 2 are positive or negative, and the outermost layers on both sides of the electrode core 7 have opposite polarities to the first electrode sheet 1 or the second electrode sheet 2 facing it.

[0050] The battery is provided with a first pole piece 1 covered with a first active material layer 3 and a second pole piece 2 covered with a second active material layer 4. The first pole piece 1 and the second pole piece 2 are combined with a pole core 7 of an outermost exposed positive pole piece 72 or a negative pole piece 71 to form a primary battery structure. At the same time, the first pole piece 1 and the second pole piece 2 are sealed to form a battery shell for accommodating the pole core 7. Therefore, the first pole piece 1 and the second pole piece 2 not only contribute to the battery capacity as the primary battery structure, but also protect the battery as a battery shell. There is no need to additionally set up a hard shell or aluminum-plastic film for packaging as in the prior art, which effectively improves the space utilization of the battery, reduces the traditional packaging structure such as the shell, reduces the preparation cost, and effectively reduces the overall mass of the battery, making the battery space more compact, and structurally improving the energy density of the battery.

[0051] It can be understood that when the first pole piece 1, the second pole piece 2 and the pole core 7 are combined to form a primary battery structure, since the first pole piece 1 is provided with a first active material layer 3 and the second pole piece 2 is provided with a second active material layer 4, the first pole piece 1 and the second pole piece 2 can be regarded as positive or negative poles, and the first active material layer 3 and the second active material layer 4 should have opposite polarity to the outermost layer of the pole core 7 facing them, that is, when the outermost layer of the pole core 7 facing the first pole piece 1 is the positive pole piece 72, the first active material layer 3 on the first pole piece 1 should be set as the negative active material layer, and when the outermost layer of the pole core 7 facing the first pole piece 1 is the negative pole piece 71, the first active material layer 3 on the first pole piece 1 should be set as the positive active material layer, and the same applies to the second active material layer 4 on the second pole piece 2.

[0052] like Figure 1 to Figure 3 As shown, in one embodiment, the polarity of the first pole piece 1 and the polarity of the second pole piece 2 are both positive or both negative.

[0053] When the polarity of the first pole piece 1 and the polarity of the second pole piece 2 are both negative, the outermost layers on both sides of the pole core 7 are both positive pole pieces 72, the first active material layer 3 and the second active material layer 4 are negative active material layers, the negative pole piece 71 is electrically connected to the first pole piece 1 and the second pole piece 2, and the positive pole pieces 72 are electrically connected to each other and led out of the battery casing.

[0054] like Figure 8 and Fig. 9 As shown, in another embodiment, the outermost layers on both sides of the pole core 7 are both negative electrode sheets 71 .

[0055] When the polarity of the first pole piece 1 and the polarity of the second pole piece 2 are both positive, the outermost layers on both sides of the pole core 7 are both negative pole pieces 71, the first active material layer 3 and the second active material layer 4 are positive active material layers, the positive pole piece 72 is electrically connected to the first pole piece 1 and the second pole piece 2, and the negative pole pieces 71 are electrically connected to each other and led out of the battery casing.

[0056] Compared with the implementation mode in which the two sides of the pole core 7 are respectively provided with a positive pole sheet 72 and a negative pole sheet 71, setting the outermost layers on both sides of the pole core 7 as the positive pole sheet 72 or the negative pole sheet 71 at the same time can ensure that the polarity of the first pole sheet 1 and the second pole sheet 2 are the same, so that when the first pole sheet 1 and the second pole sheet 2 are packaged, the first pole sheet 1 and the second pole sheet 2 can be directly abutted and connected, or the first pole sheet 1, the second pole sheet 2 and the positive pole sheet 72 of the same polarity or the negative pole sheet 71 of the same polarity in the middle can be stacked and sealed, thereby reducing the setting of the insulating structure and simplifying the processing technology.

[0057] like Figure 1 As shown, in one embodiment, the positive electrode sheet 72 includes a positive electrode current collector 721 and a positive electrode material layer 722, the positive electrode material layer 722 covers the two surfaces of the positive electrode current collector 721, and one end of the positive electrode current collector 721 is formed with a positive electrode blank area 7211 not covered with the positive electrode material layer 722, and a plurality of positive electrode blank areas 7211 are stacked on each other;

[0058] The negative electrode sheet 71 includes a negative electrode current collector 711 and a negative electrode material layer 712, wherein the negative electrode material layer 712 covers the two surfaces of the negative electrode current collector 711, and a negative electrode blank area 7111 not covered by the negative electrode material layer 712 is formed at one end of the negative electrode current collector 711, wherein a plurality of negative electrode blank areas 7111 are stacked on each other;

[0059] The negative electrode blank area 7111 and the positive electrode blank area 7211 are respectively located at two ends of the pole core 7 facing different directions.

[0060] By directly leading out the positive electrode blank areas 7211 of the plurality of positive electrode current collectors 721 and the negative electrode blank areas 7111 of the plurality of negative electrode current collectors 711 from the battery shell, respectively, during the operation of the battery, the heat generated can be conducted to the outside of the battery shell through the heat conduction of the positive electrode current collectors 721 and the negative electrode current collectors 711, which has better heat dissipation capacity and facilitates thermal management. At the same time, the internal resistance of the battery is also reduced through the large-area contact between the pole pieces.

[0061] Further, such as Figure 2 and Figure 3As shown, in this embodiment, when the polarity of the first pole piece 1 and the polarity of the second pole piece 2 are both positive, one end of the first pole piece 1, one end of the second pole piece 2 and the plurality of positive blank areas 7211 are stacked and tightly connected with each other, and the connection method is welding or bonding.

[0062] The first pole piece 1 and the second pole piece 2 are hermetically connected at both sides by welding or bonding.

[0063] A plurality of negative electrode blank areas 7111 are led out from between the other end of the first electrode sheet 1 and the other end of the second electrode sheet 2 , and the negative electrode blank areas 7111 are insulated from and hermetically connected to the first electrode sheet 1 and the second electrode sheet 2 .

[0064] In this embodiment, a first insulating layer 11 is provided on the inner side of the other end of the first pole piece 1, a second insulating layer 21 is provided on the inner side of the other end of the second pole piece 2, a first insulating glue 713 is provided on the negative electrode blank area 7111, and the first pole piece 1 and the second pole piece 2 are sealed with the negative electrode blank area 7111 by hot pressing with the first insulating glue 713.

[0065] like Figure 2 As shown, in one embodiment, a plurality of the negative electrode blank areas 7111 are stacked on top of each other and led out from between the other end of the first electrode sheet 1 and the other end of the second electrode sheet 2 .

[0066] Specifically, the plurality of negative electrode blank areas 7111 are welded together as one, and the first insulating glue 713 is disposed on both sides of the welded negative electrode blank areas 7111 to insulate each other and seal the other end of the first electrode piece 1 and the other end of the second electrode piece 2 .

[0067] like Figure 5 As shown, in other embodiments, a plurality of negative electrode blank areas 7111 are respectively led out from between the other end of the first electrode sheet 1 and the other end of the second electrode sheet 2 and then stacked on top of each other.

[0068] Specifically, the multiple negative electrode blank areas 7111 are led out from the gaps between the multiple positive electrode sheets 72 and are welded together after being led out. The first insulating glue 713 is located at the position where the negative electrode blank areas 7111 contact the positive electrode sheet 72 or the first electrode sheet 1 or the second electrode sheet 2, so as to insulate each other and seal the other end of the first electrode sheet 1 and the other end of the second electrode sheet 2.

[0069] like Fig.10 and Fig.11As shown, in another embodiment, when the polarity of the first pole piece 1 and the polarity of the second pole piece 2 are both negative, one end of the first pole piece 1, one end of the second pole piece 2 and the plurality of negative pole blank areas 7111 are stacked on top of each other and tightly connected, and the first pole piece 1 and the second pole piece 2 are tightly connected on both sides; the plurality of positive pole blank areas 7211 are led out from between the other end of the first pole piece 1 and the other end of the second pole piece 2, and the positive pole blank areas 7211 are insulated from the first pole piece 1 and the second pole piece 2 and tightly connected.

[0070] In this embodiment, a first insulating layer 11 is provided on the inner side of the other end of the first pole piece 1, a second insulating layer 21 is provided on the inner side of the other end of the second pole piece 2, a second insulating glue 723 is provided on the positive electrode blank area 7211, and the first pole piece 1 and the second pole piece 2 are sealed with the positive electrode blank area 7211 by hot pressing with the second insulating glue 723.

[0071] The first insulating layer 11 and the second insulating layer 21 are used to prevent the first pole piece 1 and the second pole piece 2 from short-circuiting by contacting with the negative electrode blank area 7111 or the positive electrode blank area 7211 of different polarities.

[0072] The first insulating layer 11 and the second insulating layer 21 are each independently selected from organic polymers and / or inorganic particles. In a preferred embodiment, the first insulating layer 11 and the second insulating layer 21 are selected from high molecular polymers that can be heat-pressed and sealed.

[0073] In other embodiments, the first insulating layer 11 may also be disposed around the first active material layer 3 , and the second insulating layer 21 may also be disposed around the second active material layer 4 .

[0074] In one embodiment, a plurality of positive electrode blank areas 7211 are stacked on top of each other and are led out from between the other end of the first electrode sheet 1 and the other end of the second electrode sheet 2;

[0075] like Fig.11 As shown, in another embodiment, a plurality of the positive electrode blank areas 7211 are respectively led out from between the other end of the first electrode sheet 1 and the other end of the second electrode sheet 2 and then stacked on top of each other.

[0076] like Figure 1 As shown, in one embodiment, the first pole piece 1, the second pole piece 2, the positive electrode current collector 721 and the negative electrode current collector 711 are sheet structures with flat surfaces.

[0077] In this embodiment, the thickness of the first pole piece 1 is 20-200 um, the thickness of the second pole piece 2 is 20-200 um, the thickness of the positive electrode current collector 721 is 3-20 um, and the thickness of the negative electrode current collector 711 is 3-20 um.

[0078] The thickness of the current collector of the first pole piece 1 and the thickness of the current collector of the second pole piece 2 are greater than or equal to the thickness of the positive electrode current collector 721 and the negative electrode current collector 711, ensuring that they have a certain packaging strength and avoiding the risk of leakage and short circuit caused by rupture of the battery shell during use.

[0079] like Figure 4 and Figure 5 As shown, in one embodiment, positive electrode accommodating grooves 7212 are provided on both surfaces of the positive electrode collector 721, the positive electrode material layer 722 is located in the positive electrode accommodating groove 7212, and a third insulating layer 724 is arranged around the outer periphery of the positive electrode material layer 722, and the positive electrode accommodating grooves 7212 of two adjacent positive electrode collectors 721 are connected to form a negative electrode accommodating cavity, the negative electrode sheet 71 and the third barrier layer 73 are located in the negative electrode accommodating cavity, and the negative electrode blank area 7111 of the negative electrode sheet 71 is led out from the negative electrode accommodating cavity and is insulated from the positive electrode sheet.

[0080] like Figure 6 and Figure 7 Shown are the front view and side view of the positive electrode sheet 72.

[0081] The preparation method of the positive electrode sheet 72 is as follows: coating a positive electrode material layer 722 on a positive electrode collector 721, and coating a third insulating layer 724 on the periphery of the positive electrode material layer 722. At this time, the negative electrode collector 711 may be coated with a fourth insulating layer 714 corresponding to the third insulating layer 724 to avoid a short circuit between the positive electrode collector 721 and the negative electrode collector 711; the positive electrode sheet 72 is stamped using a stamping device so that both surfaces of the positive electrode sheet 72 have a positive electrode receiving groove 7212, and the depth of the positive electrode receiving groove 7212 is 0.1 to 300 μm. In this embodiment, the thickness of the positive electrode collector 721 should be greater than twice the depth of the positive electrode receiving groove 7212, and the coverage of the positive electrode receiving groove 7212 on the positive electrode sheet 72 is smaller than the coverage of the third insulating layer 724 on the positive electrode sheet 72.

[0082] In one embodiment, negative electrode accommodating grooves 7112 are provided on both surfaces of the negative electrode current collector 711, the negative electrode material layer 712 is located in the negative electrode accommodating grooves 7112, and a fourth insulating layer 714 is arranged around the outer periphery of the negative electrode material layer 712. The negative electrode accommodating grooves 7112 of two adjacent negative electrode current collectors 711 are connected to form a positive electrode accommodating cavity, the positive electrode sheet 72 and the third barrier layer 73 are located in the positive electrode accommodating cavity, and the positive electrode blank area 7211 of the positive electrode sheet 72 is led out from the positive electrode accommodating cavity and is insulated from the negative electrode sheet.

[0083] The preparation method of the negative electrode sheet 71 is as follows: coating a negative electrode material layer 712 on the negative electrode current collector 711, and coating a fourth insulating layer 714 on the periphery of the negative electrode material layer 712. At this time, the positive electrode current collector 721 may be coated with a third insulating layer 724 corresponding to the fourth insulating layer 714 to avoid a short circuit between the positive electrode current collector 721 and the negative electrode current collector 711; the negative electrode sheet 71 is stamped using a stamping device so that both surfaces of the negative electrode sheet 71 have a negative electrode accommodating groove 7112, and the depth of the negative electrode accommodating groove 7112 is 0.1 to 300 μm. In this embodiment, the thickness of the negative electrode current collector 711 should be greater than twice the depth of the negative electrode accommodating groove 7112, and the coverage of the negative electrode accommodating groove 7112 on the negative electrode sheet 71 is smaller than the coverage of the fourth insulating layer 714 on the negative electrode sheet 71.

[0084] The third insulating layer 724 and the fourth insulating layer 714 are each independently selected from organic polymers and / or inorganic particles.

[0085] like Figure 4 As shown, in one embodiment, a first groove 12 is provided on the inner side of the first pole piece 1, and the first active material layer 3 and the first barrier layer 5 are located in the first groove 12; a second groove 22 is provided on the inner side of the second pole piece 2, and the second active material layer 4 and the second barrier layer 6 are located in the second groove 22.

[0086] In some embodiments, the outer sides of the first pole piece 1 and the second pole piece 2 are covered with a polymer film layer or an insulating coating layer.

[0087] In a preferred embodiment, the outer side of the first pole piece 1 and the second pole piece 2 is covered with a polymer film layer, and the polymer film layer is selected from a nylon layer. The polymer film layer can improve the strength of the battery shell and avoid the risk of leakage and short circuit caused by the rupture of the battery shell during use. At the same time, when the battery is pierced by a conductive foreign object, a conductive path is easily formed, thereby causing a short circuit. The short circuit in this mode has the maximum heat generation power, and the battery has a high risk of loss of control. If a polymer film layer is provided on the outer surface of the first pole piece 1 and the second pole piece 2, the polymer film layer, as a polymer material, has good ductility and stretchability. When a foreign object pierces, it can be wrapped on the surface of the foreign object, so that the foreign object and the aluminum foil remain in a non-contact state, thereby avoiding the above-mentioned high-risk short circuit mode. In addition, nylon is non-conductive and is provided on the outer side of the first pole piece 1 and the second pole piece 2. The surface of the battery will not be charged, which is conducive to the high-voltage safety protection design of the module or battery pack.

[0088] In a preferred embodiment, the polymer film layer is selected from nylon layer.

[0089] In this embodiment, the thickness of the current collector of the first pole piece 1 and the thickness of the current collector of the second pole piece 2 are 3-200 um, and the thickness of the polymer film layer is 2-200 um.

[0090] In some embodiments, the first barrier layer 5 , the second barrier layer 6 , and the third barrier layer 73 are each independently selected from a separator, a solid electrolyte, or a semi-solid electrolyte.

[0091] In one embodiment, the first barrier layer 5 is respectively bonded to the first active material layer 3 and the pole core 7 by adhesive coating, the second barrier layer 6 is respectively bonded to the second active material layer 4 and the pole core 7 by adhesive coating, and the third barrier layer 73 is respectively bonded to the positive electrode sheet 72 and the negative electrode sheet 71 by adhesive coating.

[0092] The first barrier layer 5, the second barrier layer 6 and the third barrier layer 73 are coated with glue in a dotted distribution. After lamination, the battery is bonded into a whole through a hot pressing process, which can prevent the positive electrode sheet 72 and the negative electrode sheet 71 from moving and misaligning on the one hand, and prevent the positive electrode sheet 72 and the negative electrode sheet 71 from bending during use or transfer on the other hand.

[0093] In some embodiments, when the first barrier layer 5, the second barrier layer 6 and the third barrier layer 73 are diaphragms, the battery housing needs to be filled with an electrolyte, which is composed of a solvent and a lithium salt. The solvent includes: a mixed solvent of one or more of carbonates, carboxylates / ethers, sulfur-containing organic solvents, nitrile / phosphorus / silicon solvents, etc.; the lithium salt is mainly one or more of LiPF6, LiBF4, LiBOB, and LiTFSI.

[0094] In some embodiments, when the first barrier layer 5, the second barrier layer 6 and the third barrier layer 73 are all-solid electrolytes, the all-solid electrolytes include a mixture of one or more of the following substances: (1) polyethylene oxide (PEO), polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), polymethyl acrylate (PMMA), polypropylene oxide (PPO), polyvinylidene chloride (PVC), and composite materials of the above materials obtained by crosslinking, copolymerization, blending and inorganic material filling; (2) oxide glass ceramics, NASICON (sodium super ion conductors) structure, garnet structure, perovskite and antiperovskite materials; (3) Li2S-SiS2, Li2S-P2S5, Li2S-GeS2, Li2S-MeS2-P2S5 (Me=Si, Ge, Sn, Al), Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 (LSPSC) and Li 9.6 P3S 12 Such as glass sulfide solid electrolyte, glass ceramic sulfide solid electrolyte and ceramic sulfide solid electrolyte.

[0095] In some embodiments, when the first barrier layer 5, the second barrier layer 6 and the third barrier layer 73 are semi-solid electrolytes, the semi-solid electrolytes are composed of three major parts: a polymer matrix, a liquid plasticizer and a lithium salt, wherein the polymer matrix includes: one or a mixture of polymers such as polyethylene oxide (PEO), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), polyvinyl chloride (PVC), polymethyl methacrylate (PMMA), polyacrylonitrile (PAN), etc.; the liquid plasticizer and the lithium salt are commercial lithium-ion battery electrolytes.

[0096] In some embodiments, the positive electrode current collector 721 is aluminum foil, the negative electrode current collector 711 is copper foil, and when the polarity of the first pole piece 1 and the second pole piece 2 is positive, the first pole piece 1 and the second pole piece 2 are selected from aluminum foil; when the polarity of the first pole piece 1 and the second pole piece 2 is negative, the first pole piece 1 and the second pole piece 2 are selected from copper foil.

[0097] It should be noted that the features of the embodiments provided by the present invention above can be combined with each other to obtain specific embodiments. All embodiments obtained by combining the above features should be included in the protection scope of the present invention. The following describes some feature combinations in the present invention through specific embodiments:

[0098] like Figure 1 to Figure 3 As shown, a schematic diagram of an implementation structure 1 of a battery is provided;

[0099] In the first embodiment, the first pole piece 1 , the second pole piece 2 , the positive electrode current collector 721 , and the negative electrode current collector 711 are sheet structures with flat surfaces.

[0100] The inner side of the first pole piece 1 is covered with a first active material layer 3, and a first barrier layer 5 is provided between the first active material layer 3 and the pole core 7; the inner side of the second pole piece 2 is covered with a second active material layer 4, and a second barrier layer 6 is provided between the second active material layer 4 and the pole core 7;

[0101] The pole core 7 includes a plurality of stacked positive electrode sheets 72 , a third barrier layer 73 and a negative electrode sheet 71 , and the outermost layers on both sides of the pole core 7 are negative electrode sheets 71 , and the first active material layer 3 and the second active material layer 4 are positive active material layers.

[0102] The positive electrode sheet 72 includes a positive electrode current collector 721 and a positive electrode material layer 722. The positive electrode material layer 722 covers two surfaces of the positive electrode current collector 721. A positive electrode blank area 7211 not covered by the positive electrode material layer 722 is formed at one end of the positive electrode current collector 721.

[0103] The negative electrode sheet 71 includes a negative electrode current collector 711 and a negative electrode material layer 712. The negative electrode material layer 712 covers the two surfaces of the negative electrode current collector 711. One end of the negative electrode current collector 711 is formed with a negative electrode blank area 7111 not covered by the negative electrode material layer 712.

[0104] One end of the first pole piece 1, one end of the second pole piece 2 and the plurality of positive electrode blank areas 7211 are stacked and tightly connected to each other, and the first pole piece 1 and the second pole piece 2 are tightly connected on both sides; the plurality of negative electrode blank areas 7111 are led out from between the other end of the first pole piece 1 and the other end of the second pole piece 2, and the negative electrode blank areas 7111 are insulated from the first pole piece 1 and the second pole piece 2 and tightly connected;

[0105] A first insulating layer 11 is disposed inside the other end of the first pole piece 1, a second insulating layer 21 is disposed inside the other end of the second pole piece 2, a first insulating glue 713 is disposed on the negative electrode blank area 7111, and the first pole piece 1 and the second pole piece 2 are sealed with the negative electrode blank area 7111 by hot pressing with the first insulating glue 713;

[0106] The plurality of negative electrode blank areas 7111 are stacked and connected to each other and are led out from between the other end of the first electrode sheet 1 and the other end of the second electrode sheet 2 .

[0107] like Figure 4 and Figure 5 As shown, a schematic diagram of the second implementation structure of the battery is provided;

[0108] Implementation structure 2 includes most of the structural features of implementation structure 1, and the differences are:

[0109] In the second embodiment, the plurality of negative electrode blank areas 7111 are respectively led out from between the other end of the first electrode sheet 1 and the other end of the second electrode sheet 2 and then are stacked and connected to each other.

[0110] Positive electrode accommodating grooves 7212 are provided on both surfaces of the positive electrode collector 721, the positive electrode material layer 722 is located in the positive electrode accommodating grooves 7212, and a third insulating layer 724 is arranged around the outer periphery of the positive electrode material layer 722. The positive electrode accommodating grooves 7212 of two adjacent positive electrode collectors 721 are connected to form a negative electrode accommodating cavity, the negative electrode sheet 71 and the third barrier layer 73 are located in the negative electrode accommodating cavity, and the negative electrode blank area 7111 of the negative electrode sheet 71 is led out of the negative electrode accommodating cavity.

[0111] A first groove 12 is provided on the inner side of the first pole piece 1, the first active material layer 3 and the first barrier layer 5 are located in the first groove 12, and a first insulating layer 11 is provided around the outer periphery of the first active material layer 3 of the first pole piece 1; a second groove 22 is provided on the inner side of the second pole piece 2, the second active material layer 4 and the second barrier layer 6 are located in the second groove 22, and a second insulating layer 21 is provided around the outer periphery of the second active material layer 4 of the second pole piece 2.

[0112] like Figure 8 and Fig. 9 As shown, a schematic diagram of the implementation structure three of the battery is provided;

[0113] In the third embodiment, the first pole piece 1 and the second pole piece 2 are sheet structures with flat surfaces.

[0114] The inner side of the first pole piece 1 is covered with a first active material layer 3, and a first barrier layer 5 is provided between the first active material layer 3 and the pole core 7; the inner side of the second pole piece 2 is covered with a second active material layer 4, and a second barrier layer 6 is provided between the second active material layer 4 and the pole core 7;

[0115] The pole core 7 includes a plurality of stacked positive electrode sheets 72 , a third barrier layer 73 and a negative electrode sheet 71 , and the outermost layers on both sides of the pole core 7 are positive electrode sheets 72 , and the first active material layer 3 and the second active material layer 4 are negative electrode active material layers.

[0116] Positive electrode accommodating grooves 7212 are provided on both surfaces of the positive electrode collector 721, the positive electrode material layer 722 is located in the positive electrode accommodating grooves 7212, and a third insulating layer 724 is arranged around the outer periphery of the positive electrode material layer 722. The positive electrode accommodating grooves 7212 of two adjacent positive electrode collectors 721 are connected to form a negative electrode accommodating cavity, the negative electrode sheet 71 and the third barrier layer 73 are located in the negative electrode accommodating cavity, and the negative electrode blank area 7111 of the negative electrode sheet 71 is led out of the negative electrode accommodating cavity.

[0117] One end of the first pole piece 1, one end of the second pole piece 2 and the plurality of negative electrode blank areas 7111 are stacked on top of each other and are tightly connected, and the first pole piece 1 and the second pole piece 2 are tightly connected on both sides; the plurality of positive electrode blank areas 7211 are led out from between the other end of the first pole piece 1 and the other end of the second pole piece 2, and the positive electrode blank areas 7211 are insulated from the first pole piece 1 and the second pole piece 2 and are tightly connected.

[0118] like Fig. 9 and Fig.10 As shown, a schematic diagram of a fourth embodiment of a battery is provided;

[0119] Implementation structure 4 includes most of the structural features of implementation structure 2, and the differences are:

[0120] The inner side of the first pole piece 1 is covered with a first active material layer 3, and a first barrier layer 5 is provided between the first active material layer 3 and the pole core 7; the inner side of the second pole piece 2 is covered with a second active material layer 4, and a second barrier layer 6 is provided between the second active material layer 4 and the pole core 7;

[0121] The pole core 7 includes a plurality of stacked positive electrode sheets 72 , a third barrier layer 73 and a negative electrode sheet 71 , and the outermost layers on both sides of the pole core 7 are positive electrode sheets 72 , and the first active material layer 3 and the second active material layer 4 are negative electrode active material layers.

[0122] The positive electrode sheet 72 includes a positive electrode current collector 721 and a positive electrode material layer 722. The positive electrode material layer 722 covers two surfaces of the positive electrode current collector 721. A positive electrode blank area 7211 not covered by the positive electrode material layer 722 is formed at one end of the positive electrode current collector 721.

[0123] The negative electrode sheet 71 includes a negative electrode current collector 711 and a negative electrode material layer 712. The negative electrode material layer 712 covers the two surfaces of the negative electrode current collector 711. One end of the negative electrode current collector 711 is formed with a negative electrode blank area 7111 not covered by the negative electrode material layer 712.

[0124] One end of the first pole piece 1, one end of the second pole piece 2 and the plurality of negative electrode blank areas 7111 are stacked and tightly connected to each other, and the first pole piece 1 and the second pole piece 2 are tightly connected to each other; the plurality of positive electrode blank areas 7211 are led out from between the other end of the first pole piece 1 and the other end of the second pole piece 2, and the positive electrode blank areas 7211 are insulated from the first pole piece 1 and the second pole piece 2 and tightly connected to each other;

[0125] The negative electrode blank area 7111 is provided with a first insulating glue 713, and the first pole piece 1 and the second pole piece 2 are sealed with the negative electrode blank area 7111 by heat pressing through the first insulating glue 713;

[0126] The plurality of positive electrode blank areas 7211 are respectively led out from between the other end of the first electrode sheet 1 and the other end of the second electrode sheet 2 and then are stacked and connected to each other.

[0127] Negative electrode accommodating grooves 7112 are provided on both surfaces of the negative electrode current collector 711, the negative electrode material layer 712 is located in the negative electrode accommodating grooves 7112, and a fourth insulating layer 714 is arranged around the outer periphery of the negative electrode material layer 712. The negative electrode accommodating grooves 7112 of two adjacent negative electrode current collectors 711 are connected to form a positive electrode accommodating cavity, the positive electrode sheet 72 and the third barrier layer 73 are located in the positive electrode accommodating cavity, and the positive electrode blank area 7211 of the positive electrode sheet 72 is led out of the positive electrode accommodating cavity.

[0128] A first groove 12 is provided on the inner side of the first pole piece 1, the first active material layer 3 and the first barrier layer 5 are located in the first groove 12, and a first insulating layer 11 is provided around the outer periphery of the first active material layer 3 of the first pole piece 1; a second groove 22 is provided on the inner side of the second pole piece 2, the second active material layer 4 and the second barrier layer 6 are located in the second groove 22, and a second insulating layer 21 is provided around the outer periphery of the second active material layer 4 of the second pole piece 2.

[0129] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A battery, characterized in that: The battery comprises a first pole piece, a second pole piece and a pole core, wherein the pole core is located between the first pole piece and the second pole piece, and the first pole piece and the second pole piece are surrounded together to form a battery housing for accommodating the pole core; A first active material layer is disposed on the inner side of the first pole piece, and a first barrier layer is disposed between the first active material layer and the pole core; a second active material layer is disposed on the inner side of the second pole piece, and a second barrier layer is disposed between the second active material layer and the pole core; The pole core comprises a plurality of stacked positive pole sheets, a third barrier layer and a negative pole sheet, the polarity of the first pole sheet and the polarity of the second pole sheet are positive or negative, and the outermost layers on both sides of the pole core have opposite polarities to the first pole sheet or the second pole sheet facing the first pole sheet or the second pole sheet; The positive electrode sheet comprises a positive electrode current collector and a positive electrode material layer, wherein the positive electrode material layer covers the two surfaces of the positive electrode current collector, and a positive electrode blank area not covered by the positive electrode material layer is formed at one end of the positive electrode current collector, and a plurality of positive electrode blank areas are stacked on each other; The negative electrode sheet comprises a negative electrode current collector and a negative electrode material layer, wherein the negative electrode material layer covers the two surfaces of the negative electrode current collector, and a negative electrode blank area not covered by the negative electrode material layer is formed at one end of the negative electrode current collector, and a plurality of negative electrode blank areas are stacked on each other; Positive electrode accommodating grooves are provided on both surfaces of the positive electrode current collector, the positive electrode material layer is located in the positive electrode accommodating grooves, a third insulating layer is provided around the periphery of the positive electrode material layer, the positive electrode accommodating grooves of two adjacent positive electrode current collectors are butted together to form a negative electrode accommodating cavity, the negative electrode sheet and the third barrier layer are located in the negative electrode accommodating cavity, and the negative electrode blank area of ​​the negative electrode sheet is led out of the negative electrode accommodating cavity and is insulated from the positive electrode sheet; or Negative electrode accommodating grooves are provided on both surfaces of the negative electrode current collector, the negative electrode material layer is located in the negative electrode accommodating groove, a fourth insulating layer is arranged around the outer periphery of the negative electrode material layer, the negative electrode accommodating grooves of two adjacent negative electrode current collectors are connected to form a positive electrode accommodating cavity, the positive electrode sheet and the third barrier layer are located in the positive electrode accommodating cavity, and the positive electrode blank area of ​​the positive electrode sheet is led out from the positive electrode accommodating cavity and is insulated from the negative electrode sheet.

2. The battery according to claim 1, characterized in that The polarity of the first pole piece and the polarity of the second pole piece are both positive or both negative; When the polarity of the first pole piece and the polarity of the second pole piece are both negative poles, the outermost layers on both sides of the pole core are both positive pole pieces, the first active material layer and the second active material layer are negative active material layers, the negative pole piece is electrically connected to the first pole piece and the second pole piece, and the positive pole pieces are electrically connected to each other and lead out of the battery housing; When the polarity of the first electrode sheet and the polarity of the second electrode sheet are both positive, the outermost layers on both sides of the electrode core are both negative electrode sheets, the first active material layer and the second active material layer are positive electrode active material layers, the positive electrode sheet is electrically connected to the first electrode sheet and the second electrode sheet, and the negative electrode sheets are electrically connected to each other and led out of the battery casing.

3. The battery according to claim 2, characterized in that The negative electrode blank area and the positive electrode blank area are respectively located at two ends of the pole core facing different directions.

4. The battery according to claim 3, characterized in that When the polarity of the first pole piece and the polarity of the second pole piece are both positive, one end of the first pole piece, one end of the second pole piece and the multiple positive blank areas are stacked on each other and tightly connected, and the first pole piece and the two sides of the second pole piece are tightly connected; the multiple negative blank areas are led out from between the other end of the first pole piece and the other end of the second pole piece, and the negative blank areas are insulated from the first pole piece and the second pole piece and tightly connected.

5. The battery according to claim 4, characterized in that A first insulating layer is disposed inside the other end of the first pole piece, a second insulating layer is disposed inside the other end of the second pole piece, a first insulating glue is disposed on the negative electrode blank area, and the first pole piece and the second pole piece are sealed with the negative electrode blank area by hot pressing through the first insulating glue; A plurality of negative electrode blank areas are stacked on each other and led out from between the other end of the first electrode piece and the other end of the second electrode piece; Alternatively, a plurality of negative electrode blank areas are respectively led out from between the other end of the first electrode sheet and the other end of the second electrode sheet and then stacked on top of each other.

6. The battery according to claim 3, characterized in that When the polarity of the first pole piece and the polarity of the second pole piece are both negative, one end of the first pole piece, one end of the second pole piece and the multiple negative pole blank areas are stacked on each other and tightly connected, and the first pole piece and the two sides of the second pole piece are tightly connected; the multiple positive pole blank areas are led out from between the other end of the first pole piece and the other end of the second pole piece, and the positive pole blank areas are insulated from the first pole piece and the second pole piece and tightly connected.

7. The battery according to claim 6, characterized in that A first insulating layer is disposed inside the other end of the first pole piece, a second insulating layer is disposed inside the other end of the second pole piece, a second insulating glue is disposed on the positive electrode blank area, and the first pole piece and the second pole piece are sealed with the positive electrode blank area by hot pressing through the second insulating glue; A plurality of positive electrode blank areas are stacked on each other and led out from between the other end of the first electrode piece and the other end of the second electrode piece; Alternatively, a plurality of positive electrode blank areas are respectively led out from between the other end of the first electrode piece and the other end of the second electrode piece and then stacked on top of each other.

8. The battery according to claim 3, characterized in that The thickness of the current collector of the first pole sheet and the thickness of the current collector of the second pole sheet are greater than or equal to the thickness of the positive electrode current collector and the negative electrode current collector.

9. The battery according to claim 1, characterized in that A first groove is provided on the inner side of the first pole piece, and the first active material layer and the first barrier layer are located in the first groove; a second groove is provided on the inner side of the second pole piece, and the second active material layer and the second barrier layer are located in the second groove.

10. The battery according to claim 1, characterized in that The first barrier layer, the second barrier layer and the third barrier layer are selected from a separator, a solid electrolyte or a semi-solid electrolyte.

11. The battery according to claim 1, characterized in that The first barrier layer is respectively bonded to the first active material layer and the core glue, the second barrier layer is respectively bonded to the second active material layer and the core glue, and the third barrier layer is respectively bonded to the positive electrode sheet and the negative electrode sheet glue.

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