Battery cell capacity balance matching structure, battery pack and electric equipment
By connecting the main battery cell with a small capacity distribution battery cell in parallel in the battery cell capacity balanced distribution structure, the problems of poor use consistency, high production costs and waste after the battery cell is connected in series, and higher consistency of battery cell capacity and lower production costs are achieved.
Patent Information
- Application Number
- CN202421365373.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-14
- Publication Date
- 2025-06-10
- Estimated Expiration
- 2034-06-14
AI Technical Summary
The existing battery cells have poor consistency in use after series connection, high production costs and waste caused by not having a battery cell set.
The battery cell capacity balanced assembly structure is adopted. By connecting the main battery cell with a small capacity distribution cell in parallel, the capacity of each battery cell is the same, the capacity difference between the series battery cell groups is reduced, and the consistency of the battery cell capacity is improved.
It improves the consistency of battery cell capacity, reduces battery cell production costs, reduces waste, and improves the reliability and service life of battery cell sets.
Smart Images
Figure CN222966187U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of batteries, and particularly relates to a cell capacity equalization and matching structure, a battery pack and an electrical equipment. Background Art
[0002] When multiple cells are connected in series, when the capacities of all cells are the same, the capacity of the battery pack after the multiple cells are connected in series is based on the consistent capacity of all cells; if the cell capacities are inconsistent, the capacity of the battery pack will be limited by the cell with the smallest capacity, and the capacity of the battery pack is based on the capacity of the cell with the smallest capacity, thus affecting the overall capacity of the battery pack. To ensure the consistency during the use of the series-connected cells, it is necessary to match the cells, and connect the cells with capacity errors within a certain range in series. However, there are differences in capacity consistency of cells with the same capacity requirement in different production cycles. Therefore, to ensure the consistency after the cells are connected in series, the requirements for the material ratio and production process control of the cells during the production process are relatively high, resulting in an increase in the production cost of the cells. However, the capacity differences of cells at different production times and different batches are inevitable. After the cells are matched, there will still be cells that cannot be matched, resulting in product waste. Summary of the Utility Model
[0003] In view of this, the utility model provides a cell capacity equalization and matching structure, a battery pack and an electrical equipment to solve the problems of poor consistency in the use of existing series-connected cells, high production cost of cells, and waste caused by the remaining unmatched cells.
[0004] In a first aspect, the utility model provides a cell capacity equalization and matching structure, which is characterized by comprising:
[0005] At least two groups of cell groups, each group of the cell groups comprising a main cell, wherein at least one group of the cell groups comprises at least one matching cell, and the main cells in each cell group are connected in parallel with the matching cells; the capacity of the main cell is greater than the capacity of the matching cell; all the cell groups are connected in series, and the capacities of all the cell groups are the same.
[0006] Beneficial effects: In the cell capacity equalization and matching structure of this configuration, by connecting the main cells in parallel with the small-capacity matching cells, the capacities of each cell group are made the same, reducing the capacity difference between the series-connected cell groups, improving the consistency of cell capacity, enabling multiple main cells to meet the requirements of capacity ratio consistency, and further enhancing the reliability and capacity retention rate of all cell groups during long-term use. Moreover, connecting the main cells in parallel with the small-capacity matching cells to make the capacities of each cell group the same can reduce the requirements for material ratio and production process during the production of the main cells, reduce the product quality control cost, and lower the production cost of the cells. Additionally, for cells that have not been successfully matched, the cell can be re-matched after being connected in parallel with the small-capacity matching cells, improving the utilization rate of the cells and reducing waste. For manufacturers that produce large-capacity cells and small-capacity cells simultaneously, the large-capacity cells and small-capacity cells can be combined for use, thereby improving the utilization rate and flexibility of the cells.
[0007] In an alternative embodiment, the cell type of the matching cells is the same as that of the main cells.
[0008] Beneficial effects: The cell type of the matching cells being the same as that of the main cells facilitates the arrangement of the main cells and the matching cells on the electrical device; it also facilitates the production of the main cells and the matching cells on the same production line.
[0009] In an alternative embodiment, the main cells include soft-pack cells, and the thickness of the main cells is greater than that of the matching cells.
[0010] Beneficial effects: It is beneficial for the main cells and the matching cells to be accommodated in the electrical device after being stacked and combined.
[0011] In an alternative embodiment, the main cells include square-shell cells, and the thickness of the main cells is greater than that of the matching cells.
[0012] In an alternative embodiment, the internal resistance of the matching cells in each cell group is greater than that of the main cells.
[0013] Beneficial effects: The internal resistance of the matching cells in each cell group being greater than that of the main cells ensures that a large current passes through the main cells and a small current passes through the matching cells during the charge and discharge processes, achieving automatic matching of the current during the charge and discharge processes, ensuring the overall cycle reliability of the cell group, and simultaneously increasing the service life of the cell group.
[0014] In an alternative embodiment, there are three sets of the cell groups.
[0015] In a second aspect, the present invention also provides a battery pack, including the cell capacity equalization and matching structure described in any one of the above.
[0016] Beneficial effects: For the battery pack with this structure, by connecting the main battery cells in parallel with the small-capacity matching battery cells, the capacities of all battery cell groups are made the same, the capacity difference between the series-connected battery cell groups is reduced, the consistency of the battery cell capacities is improved, so that multiple main battery cells meet the requirements of capacity ratio consistency, and further the reliability and capacity retention rate of all battery packs during long-term use are enhanced. At the same time, the requirements for material ratio and production process in the production process of the main battery cells can be reduced, and the quality control cost of the product can be reduced. Moreover, for the battery cells that fail to be matched successfully, they can be re-matched after being connected in parallel with the small-capacity matching battery cells, improving the utilization rate of the battery cells and reducing waste.
[0017] In an alternative embodiment, it includes a protection circuit, and the protection circuit is electrically connected to the battery cell capacity equalization and matching structure.
[0018] Beneficial effects: The protection circuit is used to protect the safety and stability of the battery cells. The protection circuit is used to detect the power, voltage, and temperature of the battery cells, prevent accidents such as overcharging, over-discharging, and short-circuiting, and ensure the service life and safety of the battery cells.
[0019] In an alternative embodiment, the protection circuit includes a battery collector, a voltage collector, a current collector, an input / output switch, and a connection port. The voltage collector is connected in parallel with each battery cell group; the current collector, the input / output switch, and the connection port are connected in series with all the battery cell groups; the voltage collector, the current collector, and the input / output switch are all electrically connected to the battery collector.
[0020] In a third aspect, the present invention further provides an electrical equipment, including the battery pack described in any one of the above. Description of the Drawings
[0021] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required to be used in the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.
[0022] Figure 1 It is a connection schematic diagram of a battery pack according to an embodiment of the present invention;
[0023] Figure 2 is Figure 1 a schematic diagram of the main battery cells in
[0024] Figure 3 is Figure 1 a schematic diagram of the matching battery cells in
[0025] Description of the reference numerals:
[0026] 1. Battery cell group; 101. Main battery cell; 102. Matching battery cell; 2. Protection circuit; 201. Battery collector; 202. Voltage collector; 203. Current collector; 204. Input / output switch; 205. Connection port. Detailed implementation manners
[0027] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some but not all of the embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.
[0028] When the capacities of battery cells are inconsistent, the capacity of the battery pack formed by connecting multiple battery cells in series is limited by the capacity of the battery cell with the smallest capacity; while the total capacity after the battery cells are connected in parallel is equal to the sum of the capacities of each battery cell. For the battery cells in the prior art, due to different production times, production batches and production raw materials, the actual capacities of the battery cells with the same nominal capacity requirement produced are different. When multiple battery cells are connected in series, it is necessary to select battery cells with similar actual capacities for matching and connecting in series. However, the difference in the actual capacities of battery cells produced at different times and in different batches cannot be avoided. After the battery cells are matched, there will still be remaining battery cells that cannot be matched, resulting in product waste.
[0029] The following combines Figures 1 to 3 , to describe the embodiments of the present utility model.
[0030] According to the embodiments of the present utility model, on the one hand, a battery cell capacity equalizing and matching structure is provided, which includes at least two groups of battery cell groups 1. Each group of battery cell groups 1 includes a main battery cell 101, and at least one group of battery cell groups 1 includes at least one matching battery cell 102. The main battery cell 101 and the matching battery cell 102 in each battery cell group 1 are connected in parallel; the capacity of the main battery cell 101 is greater than the capacity of the matching battery cell 102; all the battery cell groups 1 are connected in series, and the capacities of all the battery cell groups 1 are the same.
[0031] Since the total capacity after the parallel connection of the battery cells is equal to the sum of the capacities of each battery cell, the battery cell capacity equalization and matching structure makes the capacities of each battery cell group 1 the same by connecting the main battery cell 101 in parallel with the small-capacity matching battery cell 102, reducing the capacity difference between the series-connected battery cell groups 1, improving the consistency of the battery cell capacity, enabling multiple main battery cells 101 to meet the requirements of capacity ratio consistency, and further enhancing the reliability and capacity retention rate of all battery cell groups 1 during long-term use. Moreover, connecting the main battery cell 101 in parallel with the small-capacity matching battery cell 102 to make the capacities of each battery cell group 1 the same can reduce the requirements for material ratio and production process in the production process of the main battery cell 101, reduce the product quality control cost, and lower the production cost of the battery cell. And for the battery cells that are not successfully matched, the battery cell can be re-matched after being connected in parallel with the small-capacity matching battery cell 102, improving the utilization rate of the battery cells and reducing waste. For manufacturers that produce large-capacity battery cells and small-capacity battery cells simultaneously, the large-capacity battery cells and small-capacity battery cells can be combined for use, thus improving the utilization rate and flexibility of the battery cells.
[0032] The theoretical value of the battery cell capacity determined in the design stage is the nominal capacity of the battery cell. Due to differences in production time, production batches, and production raw materials, the actual capacities of the battery cells with the same nominal capacity requirement produced are different. After the battery cells are produced, the battery cells are first subjected to an activation test to obtain the actual capacity of the battery cells. The capacity of the matching battery cell 102 is determined according to the difference between the actual capacity of the battery cell and the theoretical nominal capacity. The required matching battery cell 102 with the required capacity is connected in parallel with the main battery cell 101 to obtain the battery cell group 1 with the required actual capacity, so as to ensure that the actual capacities of the series-connected battery cell groups 1 in the battery pack are the same.
[0033] Optionally, in one embodiment, the type of the battery cell of the matching battery cell 102 is the same as that of the battery cell of the main battery cell 101. For example, if the main battery cell 101 is a cylindrical battery cell, the matching battery cell 102 is also a cylindrical battery cell; if the main battery cell 101 is a square shell battery cell, the matching battery cell 102 is also a square shell battery cell; if the main battery cell 101 is a soft-pack battery cell, the matching battery cell 102 is also a soft-pack battery cell. The shape of the matching battery cell 102 is the same as that of the main battery cell 101, which is convenient for arranging the main battery cell 101 and the matching battery cell 102 on the electrical equipment; at the same time, it is also convenient for producing the main battery cell 101 and the matching battery cell 102 on the same production line.
[0034] In other embodiments, the shape of the matching battery cell 102 may also be different from that of the main battery cell 101. For example, the main battery cell 101 is a cylindrical battery cell, while the matching battery cell 102 is a square shell battery cell or a soft-pack battery cell. Another example is that the main battery cell 101 is a soft-pack battery cell, and the matching battery cell 102 is a cylindrical battery cell.
[0035] For example, optionally, in one embodiment, the main battery cell 101 includes a pouch cell, and the matching battery cell 102 is also a pouch cell. The large surface area of the matching battery cell 102 is the same as that of the main battery cell 101. The length and width of the large surface of the matching battery cell 102 are respectively the same as the length and width of the large surface of the main battery cell 101. The thickness of the main battery cell 101 is greater than that of the matching battery cell 102, which is beneficial to the main battery cell 101 and the matching battery cell 102 being stacked and combined and then accommodated in the electrical device.
[0036] In other embodiments, the main battery cell 101 includes a prismatic cell, and the matching battery cell 102 is also a prismatic cell. The large surface area of the matching battery cell 102 is the same as that of the main battery cell 101. The length and width of the large surface of the matching battery cell 102 are respectively the same as the length and width of the large surface of the main battery cell 101. The thickness of the main battery cell 101 is greater than that of the matching battery cell 102.
[0037] The main battery cell 101 and the matching battery cell 102 in the same battery cell group 1 are connected in parallel. During the charge and discharge process, the large current preferentially passes through the battery cell with a small internal resistance, and the current passing through the battery cell with a large internal resistance is small. The capacity of the main battery cell 101 is greater than that of the matching battery cell 102. The battery cell capacity is the time that the battery cell can continuously discharge when the battery cell discharges at a specific current. If the internal resistance of the main battery cell 101 is greater than that of the matching battery cell 102, then during the charge and discharge process, the current passing through the main battery cell 101 is small, and the current passing through the matching battery cell 102 is large. The main battery cell 101 has a long discharge time, and the matching battery cell 102 has a short discharge time, resulting in the charge and discharge cycle times of the main battery cell 101 being much greater than those of the matching battery cell 102, leading to poor overall cycle reliability of the battery cell group 1 and a short service life of the battery cell group 1.
[0038] To solve this problem, optionally, in one embodiment, the internal resistance of the matching battery cell 102 in each battery cell group 1 is greater than that of the main battery cell 101, so as to ensure that a large current passes through the main battery cell 101 and a small current passes through the matching battery cell 102 during the charge and discharge process, realizing the automatic matching of the current during the charge and discharge process, ensuring the overall cycle reliability of the battery cell group 1, and at the same time improving the service life of the battery cell group 1.
[0039] Optionally, as Figure 1 shown, in one embodiment, there are three battery cell groups 1, and the three battery cell groups 1 are connected in series. For example, for a 3S1P (3 series and 1 parallel) application product, the nominal capacity of the battery cell is 4000 mah. The normally matched battery cells are three battery cells, and the actual capacity of each battery cell is 4000 mah, and the three battery cells are connected in series.
[0040] However, due to differences in production processes and production batches, for the produced battery cells with a nominal capacity of 4000 mah, there will still be battery cells with actual capacities of 3800 mah and 3900 mah. These battery cells with a large difference between the actual capacity and the nominal capacity need to be scrapped during normal use (such as when the capacity difference between series-connected battery cells is required to be less than 30 mah), resulting in a great waste. After adopting the battery cell capacity equalization and matching structure of the present utility model, the different battery cells with a large difference between the actual capacity and the nominal capacity can be connected in parallel with small-capacity battery cells (battery cells for various wearable products) to meet the matching requirements, enabling the product to be used normally. That is, the main battery cell 101 with a capacity of 3800 mah is connected in parallel with the matching battery cell 102 with a capacity of 200 mah, and the main battery cell 101 with a capacity of 3900 mah is connected in parallel with the matching battery cell 102 with a capacity of 100 mah.
[0041] For another example, the main battery cell 101 with an actual capacity of 3500 mah is connected in parallel with the matching battery cell 102 with a capacity of 500 mah to meet the matching requirements. Thus, the requirements for material ratio and production process during the production of the main battery cell 101 can be significantly reduced, and the product quality control cost and the manufacturing cost of the battery cell can be reduced.
[0042] In other embodiments, the battery cell group 1 can also be provided with two groups, four groups, five groups, etc. The overall capacity of the battery pack can be increased by connecting the battery cell groups 1 in series, and the number of the battery cell groups 1 can be flexibly adjusted according to the actual capacity requirements. Each battery cell group 1 can include one matching battery cell 102 or more than two matching battery cells 102.
[0043] In other embodiments, among all the battery cell groups 1, only one group of the main battery cells 101 of the battery cell group 1 can be connected in parallel with the matching battery cells 102, or the main battery cells 101 of some battery cell groups 1 or all the battery cell groups 1 can be connected in parallel with the matching battery cells 102.
[0044] According to an embodiment of the present utility model, on the other hand, a battery pack is further provided, including the battery cell capacity equalization and matching structure in any one of the above.
[0045] For the battery pack with this structure, by connecting the main battery cell 101 in parallel with the small-capacity matching battery cell 102, the capacities of each battery cell group 1 are made the same, the capacity difference between the series-connected battery cell groups 1 is reduced, the consistency of the battery cell capacity is improved, so that multiple main battery cells 101 meet the capacity ratio consistency requirements, and further the reliability and capacity retention rate of all battery packs during long-term use are improved. At the same time, the requirements for material ratio and production process during the production of the main battery cell 101 can be reduced, and the product quality control cost can be reduced. And for the battery cells that are not successfully matched, the battery cell can be re-matched after being connected in parallel with the small-capacity matching battery cell 102, improving the utilization rate of the battery cell and reducing waste.
[0046] Such as Figure 1As shown, the battery pack further includes a protection circuit 2, and the protection circuit 2 is electrically connected to the cell capacity equalization and matching structure. The protection circuit 2 is used to protect the safety and stability of the cells. The protection circuit 2 is used to detect the power, voltage, and temperature of the cells, prevent accidents such as overcharging, over-discharging, and short circuits, and ensure the lifespan and safety of the cells.
[0047] Specifically, as Figure 1 shown, the protection circuit 2 includes a battery collector 201, a voltage collector 202, a current collector 203, an input / output switch 204, and a connection port 205. The voltage collector 202 is connected in parallel with each cell group 1; the current collector 203, the input / output switch 204, and the connection port 205 are connected in series with all the cell groups 1; the voltage collector 202, the current collector 203, and the input / output switch 204 are all electrically connected to the battery collector 201. The voltage collector 202 is connected in parallel with each cell group 1 to measure the voltage of each cell group 1; the current collector 203 is connected in series with all the cell groups 1 and is used to collect the current of the cell groups 1; the input / output switch 204 controls the charging and discharging of the cells; the connection port 205 serves as the connection port 205 for connecting to the outside during the charging and discharging process of the cells. The voltage collector 202, the current collector 203, and the input / output switch 204 are all electrically connected to the battery collector 201. The battery collector 201 collects parameters such as the cell temperature, voltage, and current, and the battery collector 201 controls the charging and discharging process of the cells, prevents accidents such as overcharging, over-discharging, and short circuits, and ensures the lifespan and safety of the cells.
[0048] According to an embodiment of the present invention, on the other hand, an electrical device is also provided, including the above-mentioned battery pack.
[0049] Optionally, the electrical device includes a laptop computer.
[0050] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.
Claims
1. A cell capacity balanced grouping structure, characterized in that: include: At least two groups of battery cell groups (1), each of the battery cell groups (1) comprising a main battery cell (101), wherein at least one group of the battery cell groups (1) comprises at least one matching battery cell (102), the main battery cell (101) and the matching battery cell (102) in each of the battery cell groups (1) being connected in parallel; the capacity of the main battery cell (101) being greater than the capacity of the matching battery cell (102); all the battery cell groups (1) being connected in series, and the capacities of all the battery cell groups (1) being the same; The internal resistance of the matching battery cell (102) in each battery cell group (1) is greater than the internal resistance of the main battery cell (101).
2. The cell capacity balancing group structure according to claim 1, characterized in that: The cell type of the matched cell (102) is the same as the cell type of the main cell (101).
3. The cell capacity balancing group structure according to claim 2, characterized in that: The main battery cell (101) comprises a soft-pack battery cell, and the thickness of the main battery cell (101) is greater than the thickness of the matched battery cell (102).
4. The cell capacity balancing group structure according to claim 2, characterized in that: The main battery cell (101) comprises a square shell battery cell, and the thickness of the main battery cell (101) is greater than the thickness of the matched battery cell (102).
5. The cell capacity balancing group structure according to any one of claims 1 to 4, characterized in that: The battery cell groups (1) are provided with three groups.
6. A battery pack, characterized in that: The invention comprises the battery cell capacity balancing grouping structure as described in any one of claims 1 to 5.
7. The battery pack according to claim 6, characterized in that: It also includes a protection circuit (2), wherein the protection circuit (2) is electrically connected to the battery cell capacity balancing grouping structure.
8. The battery pack according to claim 7, characterized in that: The protection circuit (2) comprises a battery collector (201), a voltage collector (202), a current collector (203), an input-output switch (204) and a connection port (205); the voltage collector (202) is connected in parallel with each of the battery cell groups (1); the current collector (203), the input-output switch (204) and the connection port (205) are connected in series with all of the battery cell groups (1); and the voltage collector (202), the current collector (203) and the input-output switch (204) are all electrically connected to the battery collector (201).
9. An electrical device, characterized in that: A battery pack comprising any one of claims 6 to 8.