Laminated battery
By interleaving positive and negative electrodes in a stacked battery and coating them with a solid electrolyte, the stacking of electrodes and separators is optimized, solving the problems of uneven heat distribution and high internal resistance in stacked batteries. This improves the battery's charge-discharge performance and cycle stability, and enhances its safety.
Patent Information
- Application Number
- CN202423232871.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-26
- Publication Date
- 2026-03-06
- Estimated Expiration
- 2034-12-26
AI Technical Summary
Stacked batteries suffer from uneven heat distribution and high internal resistance during thermal failure, which affects battery performance and lifespan, and also poses safety hazards.
The positive and negative electrodes are arranged in an alternating manner, and a solid electrolyte is coated on the electrode surface. The stacking order of the electrodes and the separator is optimized. The electrodes are compacted by pressure in the width or length direction of the shell to form a tight contact, ensuring uniform distribution of current and heat.
It reduces battery internal resistance, improves charge/discharge performance and cycle life, enhances safety, adapts to battery volume changes during charge/discharge, and reduces expansion stress.
Smart Images
Figure CN223977928U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery technology, and in particular to a stacked battery cell. Background Technology
[0002] With the rapid development of new energy technologies, batteries have been widely used in electronic devices, electric vehicles, electric two-wheelers, power tools, and other fields. Lithium-ion batteries have advantages such as high energy density, low self-discharge, good cycle performance, long service life, and safety with no pollution, and are currently widely used in electric vehicles and related fields. As the market continues to develop and consumer demands increase, higher requirements are being placed on the safety performance and thermal management of lithium-ion batteries. Improving the safety of lithium-ion batteries is closely related to the safety of individual cells, and can be achieved through improvements in cell raw materials, cell structure, and other aspects. Cell structure improvements include improvements to structural components and the overall structure of the cell.
[0003] Currently, battery cell structures include two types: wound and stacked. Stacked batteries stack the positive and negative electrode materials and the separator, unlike the traditional wound method. Compared to wound cells, stacked cells can improve energy density and safety, offering advantages in energy density, thickness control, and cycle performance. However, they also bring some specific problems: 1. In the event of thermal failure, the heat from a stacked cell diffuses two-dimensionally, causing greater impact on the casing. The stacked structure may lead to uneven heat distribution, affecting battery performance and lifespan. 2. High internal resistance affects battery charge / discharge performance, cycle life, safety performance, and rate performance. For example, batteries with high internal resistance may experience sudden voltage drops and current failure to reach rated values during high-rate discharge. 3. During charging and discharging, due to the placement direction of the electrodes, expansion and contraction, and uneven electrolyte distribution, the battery generates internal stress. This may cause the battery to bulge or expand in the thickness direction, leading to performance degradation or structural damage. Utility Model Content
[0004] The purpose of this invention is to provide a stacked battery that can reduce the internal resistance of the battery and ensure uniform distribution of current and heat inside the battery, thereby improving the charging and discharging performance and cycle life of the battery.
[0005] To achieve this objective, the present invention adopts the following technical solution:
[0006] This utility model discloses a stacked battery, comprising: a casing, the casing having a length of L, a width of W, and a thickness of T, where L > W > T; and a battery cell, the battery cell comprising a plurality of stacked electrodes, the stacking direction of the plurality of electrodes being either the length direction or the width direction of the casing.
[0007] In some embodiments, the plurality of electrodes include alternating positive and negative electrodes, at least one of the positive and negative electrodes having a solid electrolyte on its surface.
[0008] In some specific embodiments, at least one of the two surfaces of the positive electrode and the negative electrode along the stacking direction is provided with the solid electrolyte.
[0009] In some specific embodiments, the solid electrolyte is a polymer solid electrolyte, a sulfide electrolyte, or an oxide electrolyte.
[0010] In some more specific embodiments, the polymer solid electrolyte includes any one of polyethylene oxide, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, and polypropylene oxide.
[0011] In some specific embodiments, the thickness of the solid electrolyte is 5 μm-100 μm.
[0012] In some embodiments, the plurality of electrodes include alternating positive and negative electrodes, and the cell further includes a separator sandwiched between the positive and negative electrodes.
[0013] In some specific embodiments, the thickness of the diaphragm is 8μm-10μm.
[0014] In some embodiments, the plurality of electrodes include staggered positive and negative electrodes, wherein the width of the negative electrode is greater than the width of the positive electrode; wherein the width direction of the electrode is the thickness direction of the housing.
[0015] In some specific embodiments, along the width direction of the electrode, the negative electrode is positioned on both sides that extend beyond the positive electrode.
[0016] The beneficial effects of this novel stacked battery are as follows: By pressing the electrode sheets into the width or length of the casing to form a cell, the resulting cell has lower internal resistance, achieving a good stacking effect and tight contact. There is sufficient contact area between the electrode sheets, and the electrolyte can uniformly wet the electrode sheets. The stacking sequence of the electrode sheets and the separator is optimized to ensure uniform current and heat distribution inside the stacked battery, thereby improving the charge and discharge performance and cycle life of the stacked battery, as well as its charge and discharge rate performance and cycle stability. At the same time, it can adapt to the volume changes of the stacked battery during the charge and discharge process, thereby reducing the internal expansion stress of the cell.
[0017] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the stacked battery structure according to Embodiment 1 of this utility model;
[0019] Figure 2 This is a schematic diagram of the stacked battery structure according to Embodiment 2 of this utility model.
[0020] Figure label:
[0021] 100, casing; 200, battery cell. Detailed Implementation
[0022] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.
[0023] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0024] In the description of this embodiment, the terms "upper," "lower," "left," "right," "front," and "rear," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.
[0025] This utility model discloses a stacked battery, referenced... Figure 1 and Figure 2 As shown, the stacked battery includes a housing 100 and a cell 200. The housing 100 has a length of L, a width of W, and a thickness of T, where L > W > T. The cell 200 includes multiple stacked electrodes, and the stacking direction of the multiple electrodes is either the length direction or the width direction of the housing 100.
[0026] Understandably, compared to the existing technology of stacking electrodes along the thickness direction of the battery casing 100, the stacking direction of multiple electrodes in this embodiment is either the length or width direction of the casing 100. This shortens the electron transport path, and the distance electrons travel from one end of the electrode to the other is relatively short, meaning that electrons encounter less resistance during conduction, thereby reducing electronic impedance. It also achieves a multi-electrode parallel effect; the width-direction stacking can be equivalent to multiple small electrodes connected in parallel. This multi-electrode parallel structure can significantly reduce the internal resistance of the cell 200, giving it better conductivity. Furthermore, it ensures uniform current distribution, preventing localized excessive or insufficient current, thus reducing additional resistance caused by uneven current distribution. Finally, it ensures good contact between the electrodes; during the stacking process, the electrodes in both the width and length directions can achieve relatively tight and good contact, allowing electrons to conduct more easily between the electrodes, further reducing internal resistance. Thus, by pressing the electrode sheets into the width or length of the casing 100 to form the cell 200, the cell 200 has a lower internal resistance, achieving a good stacking effect and tight contact. There is sufficient contact area between the electrode sheets, and the electrolyte can uniformly wet the electrode sheets. The stacking order of the electrode sheets and the separator is optimized to ensure uniform current and heat distribution inside the stacked battery, thereby improving the charge and discharge performance and cycle life of the stacked battery, improving the charge and discharge rate performance and cycle stability of the stacked battery. At the same time, it can adapt to the volume changes of the stacked battery during the charge and discharge process, thereby reducing the internal expansion stress of the cell 200.
[0027] Optionally, the multiple electrodes include staggered positive and negative electrodes, with at least one surface of the positive and negative electrodes coated with a solid electrolyte. Current stacked batteries often use electrolyte as the conductive medium. Due to the liquid nature of the electrolyte, safety issues such as electrolyte leakage, combustion, and even explosion are prone to occur. In this embodiment, in the alternately stacked positive and negative electrodes, a solid electrolyte layer is formed by coating at least one surface of adjacent positive and negative electrodes. This ensures uniform wetting inside the battery and promotes uniform electrolyte penetration and long-term retention, thereby improving the performance, safety, and production efficiency of the stacked battery. Furthermore, the ion transport path of the electrodes coated with solid electrolyte is relatively fixed, the migration rate is relatively stable, the interface stability is better, and side reactions are less likely to occur. This better maintains the integrity of the electrode / electrolyte interface, reduces the increase in interface impedance, and helps maintain the cycle stability and coulombic efficiency of the stacked battery. Safety is greatly improved, and the risk of thermal runaway is reduced. Furthermore, solid electrolytes do not participate in electrode reactions and can be made thinner, saving more space for stacked batteries to accommodate active materials, thereby increasing the energy density of the battery.
[0028] Optionally, at least one of the two surfaces of the positive and negative electrodes along the stacking direction is provided with a solid electrolyte. It should be noted that in some embodiments, both surfaces of each positive electrode are provided with a solid electrolyte, while no solid electrolyte is provided on the negative electrode; in other embodiments, both surfaces of each negative electrode are provided with a solid electrolyte, while no solid electrolyte is provided on the positive electrode; in some embodiments, the downstream surface of each positive electrode and the downstream surface of each negative electrode along the stacking direction are provided with a solid electrolyte; and sometimes, the upstream surface of each positive electrode and the upstream surface of each negative electrode along the stacking direction are provided with a solid electrolyte. In other words, the position and distribution of the solid electrolyte can be adjusted according to actual needs, as long as there is solid electrolyte between adjacent positive and negative electrodes.
[0029] Optionally, the solid electrolyte can be a polymer solid electrolyte, a sulfide electrolyte, or an oxide electrolyte. Specifically, polymer solid electrolytes include any one of polyethylene oxide, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, and polypropylene oxide. Of course, the type of solid electrolyte can also be manufactured from other materials according to actual needs, and is not limited to the above limitations.
[0030] Optionally, the thickness of the solid electrolyte is 5μm-150μm. Alternatively, the thickness of the solid electrolyte can be 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm, or 100μm. Of course, other values within the range of 5μm-100μm are also possible, and it is not limited to the examples listed above. It is understood that in actual manufacturing, an excessively large or small thickness of the solid electrolyte will affect the performance of the stacked battery. In this embodiment, controlling the thickness of the solid battery medium between 5μm and 100μm ensures the performance of the stacked battery. Of course, in other embodiments of this invention, the thickness of the solid battery medium can be selected according to actual needs and is not limited to the above limitations.
[0031] Optionally, the multiple electrodes include alternating positive and negative electrodes, and the cell 200 also includes a separator sandwiched between the positive and negative electrodes. The separator thickness is 8μm-10μm. Specifically, the separator thickness can be 8μm, 8.1μm, 8.2μm, 8.3μm, 8.4μm, 8.5μm, 8.6μm, 8.7μm, 8.8μm, 8.9μm, 9μm, 9.1μm, 9.2μm, 9.3μm, 9.4μm, 9.5μm, 9.6μm, 9.7μm, 9.8μm, 9.9μm, or 10μm. Of course, other values within the range of 8μm-10μm are also possible, and the thickness is not limited to the examples listed above. It is understandable that in actual manufacturing, excessively thick or thin separators will affect the performance of stacked batteries. In this embodiment, a separator thickness of 8μm-10μm ensures the performance of the stacked batteries. Of course, in other embodiments of this invention, the separator thickness can be selected according to actual needs and is not limited to the above limitations.
[0032] Optionally, the multiple electrodes include staggered positive and negative electrodes, with the width of the negative electrode being greater than the width of the positive electrode. The width direction of the electrode is the thickness direction of the casing 100. It is understood that the portion of the negative electrode extending beyond the positive electrode is called the overhang region. The main function of the overhang region is to provide sufficient lithium storage space for the negative electrode, preventing lithium ions released from the positive electrode from reaching the negative electrode, thereby avoiding lithium plating on the negative electrode.
[0033] Alternatively, along the width of the electrode, both sides of the negative electrode extend beyond the positive electrode. This minimizes the possibility of lithium plating on the negative electrode.
[0034] Refer to the table below for the performance differences between the stacked battery of this embodiment and the stacked battery of the prior art.
[0035] Table 1
[0036]
[0037] In Table 1, Scheme A is a stacked cell with stacked sheets in the thickness direction; Scheme B is a stacked cell with stacked sheets in the width direction; Scheme C is a stacked cell with stacked sheets in the length direction; Scheme D is a stacked cell coated with a solid electrolyte and stacked in the width direction; and Scheme E is a stacked cell coated with a solid electrolyte and stacked in the length direction.
[0038] As shown in Table 1, the stacked battery of scheme A (i.e., the prior art) has a larger cell internal resistance, thickness expansion rate, and charge / discharge temperature rise. Schemes B, C, D, and E are all schemes proposed by this utility model. The cell internal resistance, thickness expansion rate, and charge / discharge temperature rise of the stacked battery of the above four schemes are all lower than those of scheme A, indicating that the stacked battery disclosed by this utility model has good performance.
[0039] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0040] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.
Claims
1. A stacked battery, characterized by, Comprising: A shell (100), the shell (100) has a length L, a width W, and a thickness T, L>W>T; An electric core (200), the electric core (200) comprises a plurality of laminated electrode sheets, the laminated direction of the plurality of electrode sheets is the length direction or the width direction of the shell (100).
2. The stacked battery of claim 1, wherein The plurality of electrode sheets comprises positive electrode sheets and negative electrode sheets arranged alternately, at least one surface of the positive electrode sheets and the negative electrode sheets is provided with a solid-state electrolyte.
3. The stacked battery of claim 2, wherein, At least one of the two surfaces of the positive electrode sheets and the negative electrode sheets in the stacking direction is provided with the solid-state electrolyte.
4. The stacked battery of claim 2, wherein, The solid-state electrolyte is a polymer solid-state electrolyte, a sulfide electrolyte or an oxide electrolyte.
5. The stacked battery of claim 4, wherein, The polymer solid-state electrolyte comprises any one of polyethylene oxide, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, polypropylene oxide.
6. The stacked battery of claim 2, wherein, The thickness of the solid-state electrolyte is 5-100 μm.
7. The stacked battery of claim 1, wherein The plurality of electrode sheets comprises positive electrode sheets and negative electrode sheets arranged alternately, the electric core (200) further comprises a separator clamped between the positive electrode sheets and the negative electrode sheets.
8. The stacked battery of claim 7, wherein, The thickness of the separator is 8-10 μm.
9. The stacked battery of claim 1, wherein, The plurality of electrode sheets comprises positive electrode sheets and negative electrode sheets arranged alternately, the width of the negative electrode sheets is greater than that of the positive electrode sheets; wherein: the width direction of the electrode sheets is the thickness direction of the shell (100).
10. The stacked battery of claim 9, wherein, Along the width direction of the electrode sheets, the two sides of the negative electrode sheets arranged oppositely both exceed the positive electrode sheets.