Battery pack

Abstract

The utility model relates to a kind of battery pack, configured to power electric tool, including shell;Interface, configured to be detachably connected with electric tool or charging equipment;Interface includes terminal assembly, and terminal assembly includes positive electrode terminal and negative electrode terminal, and positive electrode terminal and negative electrode terminal are configured to the corresponding terminal of electric tool or charging equipment electrically connected, to realize the electric connection of battery pack and electric tool or charging equipment;Battery cell component, set in shell, with terminal assembly electrically connected, including multiple mutually electrically connected single battery cell, and single battery cell is cylindrical battery cell;When interface is electrically connected with charging equipment, and in the real-time voltage of single battery cell during charging process is 2.5-4.2V, single battery cell can be continuously charged with greater than or equal to 3C charging rate.

Description

Technical Field

[0001] This utility model relates to a battery pack. Background Technology

[0002] Due to the increasingly severe environmental pollution problem and the depletion of fossil energy, rechargeable battery packs have entered more and more application fields, such as the power tool industry.

[0003] To provide better performance, battery packs need to offer higher output characteristics. For example, to keep the cost per use low, battery packs need to have a long lifespan; and to improve the efficiency of power tools, battery packs need to offer higher discharge power.

[0004] This section provides background information related to this application, which is not necessarily prior art. Utility Model Content

[0005] This application provides a battery pack configured to power a power tool, comprising: a housing; an interface configured to be detachably connected to the power tool or a charging device; the interface including a terminal assembly comprising a positive terminal and a negative terminal, the positive terminal and the negative terminal being configured to electrically connect to corresponding terminals of the power tool or the charging device to achieve electrical connection between the battery pack and the power tool or the charging device; and a cell assembly disposed within the housing and electrically connected to the terminal assembly, comprising multiple interconnected individual cells, the individual cells being cylindrical cells; when the interface is electrically connected to the charging device, and during charging the real-time voltage of the individual cell is between 2.5-4.2V, the individual cell can be continuously charged at a charging rate greater than or equal to 3C.

[0006] This application provides a battery pack configured to power a power tool, comprising: a housing; an interface configured to be detachably connected to the power tool or a charging device; the interface including a terminal assembly comprising a positive terminal and a negative terminal configured to electrically connect corresponding terminals of the power tool or the charging device to achieve electrical connection between the battery pack and the power tool or the charging device; and a cell assembly disposed within the housing and electrically connected to the terminal assembly, comprising multiple interconnected individual cells, wherein each individual cell is a cylindrical cell; when the interface is electrically connected to the charging device, each individual cell can receive a charging current greater than or equal to 6A.

[0007] This application provides a battery pack configured to power a power tool, comprising: a housing; an interface configured to be detachably connected to the power tool or a charging device; the interface including a terminal assembly comprising a positive terminal and a negative terminal, the positive terminal and the negative terminal being configured to electrically connect to corresponding terminals of the power tool or the charging device to achieve electrical connection between the battery pack and the power tool or the charging device; and a cell assembly disposed within the housing and electrically connected to the terminal assembly, comprising multiple interconnected individual cells, the individual cells being cylindrical cells; when the interface is electrically connected to the charging device, the individual cells can be continuously charged at a charging rate of 3C and the charging time during the constant current charging phase is less than or equal to 20 minutes.

[0008] This application provides a battery pack configured to power a power tool, comprising: a housing; an interface configured to be detachably connected to the power tool or a charging device; the interface including a terminal assembly comprising a positive terminal and a negative terminal, the positive terminal and the negative terminal being configured to electrically connect to corresponding terminals of the power tool or the charging device to achieve electrical connection between the battery pack and the power tool or the charging device; and a cell assembly disposed within the housing and electrically connected to the terminal assembly, comprising multiple interconnected individual cells, the individual cells being cylindrical cells; when the interface is electrically connected to the charging device, the individual cells can be continuously charged at a charging rate of 3C, and the capacity charged into the individual cells during the constant current charging phase is greater than or equal to 80% of the nominal capacity of the individual cells.

[0009] In some embodiments, the single battery cell is a 21700 cell and / or an 18650 cell.

[0010] In some embodiments, the gravimetric energy density of the single cell is greater than or equal to 170Wh / Kg; and / or, the volumetric energy density of the single cell is greater than or equal to 420Wh / L.

[0011] In some embodiments, the single cell includes a positive electrode, a negative electrode, and tabs connected to the positive and / or negative electrodes, the tabs being configured to draw out the power of the single cell, and there are two or more tabs.

[0012] In some embodiments, the cell assembly further includes: a positive output terminal electrically connected to the positive electrode of at least one individual cell, outputting a positive potential of the cell assembly; a negative output terminal electrically connected to the negative electrode of at least one individual cell, outputting a negative potential of the cell assembly; a positive current-carrying plate electrically connected between the positive output terminal and the positive terminal; and a negative current-carrying plate electrically connected between the negative output terminal and the negative terminal.

[0013] In some embodiments, the width of the positive electrode current carrier plate and / or the negative electrode current carrier plate ranges from 7 to 10 mm.

[0014] In some embodiments, the battery pack further includes a circuit board configured to electrically connect the terminal assembly and the cell assembly, wherein the terminal assembly, the positive current-carrying plate, and the negative current-carrying plate are disposed on the same side of the circuit board.

[0015] In some embodiments, the positive and negative current-carrying plates are located on the side of the circuit board away from the individual battery cell.

[0016] In some embodiments, the circuit board is provided with a positive electrode welding hole, and the positive electrode current-carrying plate is welded to the circuit board through the positive electrode welding hole. A positive electrode through-hole is provided on the positive electrode current-carrying plate at a position corresponding to the positive electrode welding hole. The positive terminal passes through the positive electrode through-hole and the positive electrode welding hole to achieve welding with the circuit board. And / or, the circuit board is provided with a negative electrode welding hole, and the negative electrode current-carrying plate is welded to the circuit board through the negative electrode welding hole. A negative electrode through-hole is provided on the negative electrode current-carrying plate at a position corresponding to the negative electrode welding hole. The negative terminal passes through the negative electrode through-hole and the negative electrode welding hole to achieve welding with the circuit board.

[0017] In some embodiments, the battery pack further includes a fuse connected to the positive or negative current-carrying plate.

[0018] In some embodiments, the positive electrode current-carrying plate includes a first positive electrode segment and a second positive electrode segment, and the fuse is connected between the first positive electrode segment and the second positive electrode segment; and / or, the negative electrode current-carrying plate includes a first negative electrode segment and a second negative electrode segment, and the fuse is connected between the first negative electrode segment and the second negative electrode segment.

[0019] In some embodiments, the battery pack further includes a circuit board electrically connected to the terminal assembly and the cell assembly; the cell assembly further includes connecting tabs, each connecting tab comprising: a first positive connecting tab and a second positive connecting tab interconnected and at least partially overlapping in the longitudinal direction of the individual cell, the first positive connecting tab being electrically connected to the positive electrode of at least one cell, the second positive connecting tab including a positive output terminal connected to the circuit board, the positive output terminal outputting a positive potential of the cell assembly; and a first negative connecting tab and a second negative connecting tab interconnected and at least partially overlapping in the longitudinal direction of the individual cell, the first negative connecting tab being electrically connected to the negative electrode of at least one cell, the second negative connecting tab including a negative output terminal connected to the circuit board, the negative output terminal outputting a negative potential of the cell assembly.

[0020] In some embodiments, the conductivity of the second positive electrode connector is greater than that of the first positive electrode connector; and / or, the conductivity of the second negative electrode connector is greater than that of the first negative electrode connector.

[0021] In some embodiments, the first positive electrode connector includes a first positive electrode welding portion and a second positive electrode welding portion respectively welded to the positive electrodes of two individual battery cells, and the overlapping area of ​​the first positive electrode connector and the second positive electrode connector is located in the current path between the first positive electrode welding portion and the second positive electrode welding portion; and / or, the first negative electrode connector includes a first negative electrode welding portion and a second negative electrode welding portion respectively welded to the negative electrodes of two individual battery cells, and the overlapping area of ​​the first negative electrode connector and the second negative electrode connector is located in the current path between the first negative electrode welding portion and the second negative electrode welding portion.

[0022] In some embodiments, the second positive electrode connector includes a positive electrode overlapping portion located at one end of the cell assembly along the longitudinal direction of the individual cell and a positive electrode bending portion arranged at an angle to the positive electrode overlapping portion and the positive electrode output terminal, wherein the positive electrode output terminal is bent towards the circuit board from the positive electrode bending portion and connected to the circuit board; and / or, the second negative electrode connector includes a negative electrode overlapping portion located at the other end of the cell assembly along the longitudinal direction of the individual cell and a negative electrode bending portion arranged at an angle to the negative electrode overlapping portion and the negative electrode output terminal, wherein the negative electrode output terminal is bent towards the circuit board from the negative electrode bending portion and connected to the circuit board.

[0023] In some embodiments, the battery pack further includes a circuit board and a temperature sensor. The circuit board is configured to electrically connect the terminal assembly and the cell assembly. The temperature sensor is electrically connected to the circuit board and includes a flexible sheet and a temperature-sensing block attached to the flexible sheet. The temperature sensor is configured to be clamped between two adjacent individual cells so that the temperature-sensing block is in close contact with at least one individual cell.

[0024] This application also provides a battery pack configured to power a power tool, comprising: a housing; an interface configured to be detachably connected to the power tool or a charging device, the interface including a terminal assembly including a positive terminal and a negative terminal, the positive terminal and the negative terminal being configured to electrically connect to corresponding terminals of the power tool to achieve electrical connection between the battery pack and the power tool; a cell assembly disposed within the housing, comprising multiple interconnected individual cells, the individual cells being cylindrical cells, the cell assembly being configured to be electrically connected to the terminal assembly; the individual cells being charged at a continuous charging rate of 5C and discharged at a continuous discharging rate of 5C, and after 3000 charge-discharge cycles, the capacity retention rate of the individual cells is at least 75%.

[0025] In some embodiments, the individual battery cell is charged at a continuous charging rate of 5C and discharged at a continuous discharging rate of 10C, and the capacity retention rate of the individual battery cell is at least 75% after 2000 charge-discharge cycles.

[0026] In some embodiments, the individual battery cell is charged at a continuous charging rate of 5C and discharged at a continuous discharging rate of 15C, and the capacity retention rate of the individual battery cell is at least 70% after 1600 charge-discharge cycles.

[0027] In some embodiments, when the interface is electrically connected to the power tool, and the battery pack discharges to the power tool at a continuous discharge current of 40A or more at room temperature, the depth of discharge of the battery pack is greater than or equal to 80%.

[0028] In some embodiments, when the interface is electrically connected to the power tool, the battery pack outputs a power greater than 700W to the power tool.

[0029] In some embodiments, when the interface is electrically connected to the power tool, and the individual battery cell discharges to the power tool at a continuous discharge rate of greater than or equal to 10C at room temperature, the depth of discharge of the individual battery cell is greater than or equal to 95%.

[0030] In some embodiments, when the interface is electrically connected to the power tool, the individual battery cell discharges to the power tool at a continuous discharge rate of 10C at room temperature, and the temperature rise of the individual battery cell does not exceed 48K when the discharge is completed. Attached Figure Description

[0031] The embodiments of this application will be further described in conjunction with the following figures:

[0032] Figure 1 This application provides a schematic diagram of a battery pack installed on a power tool.

[0033] Figure 2 This application provides a schematic diagram of the battery pack being installed in a charging device.

[0034] Figure 3 A schematic diagram of the battery pack provided in this application.

[0035] Figure 4 This is an exploded view of the battery pack provided in this application.

[0036] Figure 5 and Figure 6 These are schematic diagrams of the battery pack provided in this application after the casing has been removed, viewed from different angles.

[0037] Figure 7This is a schematic diagram of the terminal assembly, positive current-carrying plate, and negative current-carrying plate provided in this application mounted on a circuit board.

[0038] Figure 8 This is an exploded view of the battery cell assembly provided in this application.

[0039] Figure 9 This is a schematic diagram of the internal structure of a single battery cell provided in this application.

[0040] Figure 10 This is a schematic diagram of the first support provided in this application.

[0041] Figure 11 This is a cross-sectional view of the battery cell assembly provided in this application. Detailed Implementation

[0042] The present application will now be described in detail with reference to the embodiments shown in the accompanying drawings. However, these embodiments do not limit the present application, and any structural, methodological, or functional modifications made by those skilled in the art based on these embodiments are included within the protection scope of the present application.

[0043] It should be noted that when an element is described as "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. In the illustrated embodiments, the directional representations, i.e., up, down, left, right, front, and back, are relative and used to explain the relative structure and movement of different components in this application. These representations are appropriate when the components are in the positions shown in the figures. However, if the description of the component positions changes, then these representations are considered to change accordingly.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0045] like Figure 1 As shown, the battery pack 10 is configured to be detachably mounted to the power tool 50. Figure 1 Only a portion of the power tools are shown in the diagram, to power power tool 50. It should be noted that the power tools in this application can be configured as handheld power tools such as electric drills, angle grinders, hot glue guns, and electric hammers, or as garden power tools such as chainsaws, lawnmowers, push lawnmowers, and smart lawnmowers. Additionally, as... Figure 2As shown, the battery pack 10 is also configured to be detachably mounted to the charging device 60 so that the charging device 60 supplies power to the battery pack 10.

[0046] It should be noted that when the battery pack 10 is installed on the power tool, the direction from which the power tool 50 is viewed from the battery pack 10 is defined as upward, and the opposite direction of upward is defined as downward. The sliding direction of the battery pack 10 when installed on the power tool 50 is defined as forward, and the sliding direction of the battery pack 10 when removed from the power tool 50 is defined as backward. The direction that is perpendicular to both the up-down and forward-backward directions is defined as the left-right direction.

[0047] like Figures 3 to 11 As shown, the battery pack 10 includes a housing 100, a cell assembly 200 disposed within the housing 100, and an interface 300.

[0048] In the illustrated embodiment, the housing 100 includes an upper housing 101 and a lower housing 102 connected to the upper housing 101. The upper housing 101 and the lower housing 102 can be connected by fasteners (such as screws or pins) or snap-fit ​​connections. When the upper housing 101 and the lower housing 102 are connected, they enclose a receiving cavity. The battery cell assembly 200 is located within the receiving cavity formed by the upper housing 101 and the lower housing 102.

[0049] Interface 300 is configured to be detachably connected to power tool 50 or charging device 60. Interface 300 includes terminal assembly 310, which includes a positive terminal 311 and a negative terminal 312. The positive terminal 311 and negative terminal 312 are configured to electrically connect to corresponding terminals of power tool 50 or charging device 60 to achieve electrical connection between battery pack 10 and power tool 50 or charging device 60. Optionally, there may be one or more positive terminals 311 and negative terminals 312. Optionally, terminal assembly 310 also includes signal terminal 313, which connects to corresponding terminals of power tool 50 or charging device 60 and can transmit control signals.

[0050] In some embodiments, the interface 300 further includes a pair of guide rails 301 and 302, which are configured to guide the mechanical connection between the battery pack 10 and the power tool 50 or the charging device 60. Specifically, the pair of guide rails 301 and 302 are respectively disposed on both sides of the housing 100 and extend longitudinally along the sliding direction. Optionally, the sliding direction is set to a front-to-back direction. Of course, those skilled in the art can also configure the guide rails in other forms, such as guide grooves, as long as they can guide the battery pack to a detachable mechanical connection with the electrical equipment; this application does not impose any limitations on this.

[0051] The cell assembly 200 is electrically connected to the terminal assembly 310. The cell assembly 200 includes multiple interconnected individual cells 201, wherein each individual cell 201 is a cylindrical cell. Cylindrical cells have low cost and good consistency due to standardized production, making them more suitable for assembling into battery packs of different specifications. Optionally, the individual cell 201 is a lithium-ion cell.

[0052] In the illustrated embodiments, such as Figure 7 As shown, the battery cell assembly 200 includes 10 individual battery cells 201, which are electrically connected to each other. Each individual battery cell 201 extends longitudinally in the left-right direction, and the 10 individual battery cells 201 are arranged in two rows, with 5 individual battery cells 201 arranged in each row. The individual battery cells 201 in each row are spaced apart in the front-back direction. The number of individual battery cells can also be other, such as 3, 6, 10, 15, etc.

[0053] Optionally, the nominal voltage of each individual cell 201 is 3.6V, and the maximum voltage of each individual cell 201 is 4.2V. The five individual cells 201 in the upper and lower rows are connected in series, and the two rows of individual cells 201 are connected in parallel. Therefore, the nominal voltage of the battery pack 10 is 18V, and the maximum voltage of the battery pack 10 is 20V. Of course, the nominal voltage of the battery pack can also be 36V, 48V, 56V, 72V, or others, and this application does not limit this. Correspondingly, the series and parallel connection method between individual cells can be adjusted according to the voltage of the individual cell and the nominal voltage of the battery pack. For example, individual cells can be connected in series or in parallel, or a combination of series and parallel connections, to form a cell assembly.

[0054] In some embodiments, at least one individual cell is an 18650 cylindrical cell having a diameter of about 18 mm and a length of about 65 mm. In some embodiments, at least one individual cell is a 21700 cylindrical cell having a diameter of about 21 mm and a length of about 70 mm.

[0055] As the core component of a battery pack, the performance of a single battery cell has a crucial impact on the output characteristics of the battery pack.

[0056] Cylindrical battery cells typically consist of a positive electrode, a negative electrode, a separator, an electrolyte, and a cylindrical casing. For example, the positive electrode, separator, and negative electrode are stacked sequentially, wound longitudinally, and then assembled into a cylindrical casing. In this wound configuration, the electrolyte is positioned between the opposing surfaces of the positive and negative electrodes. Optionally, the positive electrode material can be lithium cobalt oxide, ternary materials, or lithium iron phosphate, while the negative electrode material can be graphite or silicon-based composite materials.

[0057] like Figure 8As shown, a single battery cell 201 includes a positive electrode 201a, a negative electrode 201b, and tabs 201c connected to the positive electrode 201a and / or the negative electrode 201b. The tabs 201c are configured to draw power from the single battery cell 201, and there are at least two tabs 201c. For example, there can be three, four, five, etc. By setting the number of tabs to at least two, the lateral current transmission distance is shorter, the internal resistance of the single battery cell can be lower, resulting in less energy loss during charging and discharging, and thus improving efficiency.

[0058] Because the internal resistance of a single battery cell is low, the temperature rise of the single cell during discharge is also low, resulting in a lower temperature rise for the entire battery pack after packaging. In some embodiments, when a single battery cell 201 is discharged at a continuous discharge rate of 10°C or higher at room temperature, the temperature rise of the single battery cell 201 is less than or equal to 48K. This avoids triggering over-temperature protection due to excessively high single-cell temperatures during high-rate discharge.

[0059] In some embodiments, the volumetric energy density of a single battery cell 201 is greater than or equal to 430 Wh / L. For example, the volumetric energy density of a single battery cell is greater than or equal to 450 Wh / L, or greater than or equal to 500 Wh / L, or greater than or equal to 550 Wh / L, or greater than or equal to 600 Wh / L.

[0060] In some embodiments, the gravimetric energy density of a single battery cell 201 is greater than or equal to 170 Wh / kg. For example, the gravimetric energy density of the battery cell is greater than or equal to 200 Wh / kg, or greater than or equal to 250 Wh / kg, or greater than or equal to 300 Wh / kg, or greater than or equal to 350 Wh / kg.

[0061] A high volumetric energy density or gravimetric energy density of a single battery cell results in a high energy density per unit volume or per unit weight. Therefore, battery packs can also achieve small size and high energy density, or light weight and high energy density, which not only makes them convenient for users but also provides long-lasting power for power tools.

[0062] For users who use power tools for extended periods daily, battery packs are essential for providing long-lasting power. Currently, there are generally two solutions to address the issue of continuous work over extended periods. The first is to purchase a large-capacity battery pack, but these are typically bulky and heavy, making them inconvenient to use and carry. The second solution is to purchase multiple small-capacity battery packs, allowing for relay charging when one runs out. To control costs and ensure portability, the number of battery packs should not be excessive. Therefore, if they can be quickly recharged after depletion, a relatively small number of battery packs can enable extended periods of uninterrupted work.

[0063] However, commercially available battery packs typically cannot meet the requirements for fast charging. Taking the common ternary lithium-ion 18650 battery pack as an example, its continuous charging rate is usually 0.5C-1C, resulting in a very slow charging speed that cannot meet the need for rapid switching of power to power tools. The charging rate of individual battery cells is a crucial factor affecting the overall charging rate of the battery pack.

[0064] To ensure the battery pack's charging rate meets the needs of power tools and improves their efficiency, when interface 300 is electrically connected to charging device 60, and the real-time voltage of individual battery cell 201 is between 2.5-4.2V during charging, individual battery cell 201 can continuously charge at a charging rate greater than or equal to 3C.

[0065] For safe and efficient charging, the charging process of a single battery cell typically includes a constant current charge (CC) stage and a constant voltage charge (CV) stage.

[0066] During the constant current charging phase, the charging device charges the individual battery cells with a constant, relatively large current. Most of the capacity is added to the individual cells during this phase. As the capacity stored in the individual cells increases, their voltage gradually rises. When the voltage of the individual cell reaches the set charging cutoff voltage, the constant current charging phase ends, and the charging device switches to the constant voltage charging phase. In the constant voltage charging phase, the charging device maintains a constant voltage (i.e., the set charging cutoff voltage) to charge the individual cells. As the internal chemical potential energy of the individual cell gradually approaches full charge, the current provided by the charging device gradually decreases. When the charging current decreases to the preset cutoff current, the charging process terminates. During the constant voltage charging phase, the charging device charges the individual cells to nearly 100% capacity, but the charging speed is slower, ensuring safe full charging and preventing overcharging.

[0067] Typically, the charging cutoff voltage of a lithium-ion battery cell is 4.2V. This means that in the above solution, during the entire process of a single battery cell going from low charge to constant current charging, the single battery cell can support continuous charging at a charging rate of 3C or higher, avoiding the problem of slow charging speed when the battery is low.

[0068] In some embodiments, when the interface 300 is electrically connected to the charging device 60, and the real-time voltage of the single cell 201 is between 2.5 and 4.2V during charging, the continuous charging rate of the single cell 201 can reach 3C to 10C. For example, it can be 3C, 4C, 6C, 7C, 8C, 9C, or 10C.

[0069] In some embodiments, the continuous charging rate of the battery pack 10 is not less than 3C. The higher the allowed charging rate of the battery pack, the shorter the time required to fully charge the battery pack, thereby saving users a significant amount of charging waiting time.

[0070] In some embodiments, when the interface 300 is electrically connected to the charging device 60, the individual battery cell 201 can receive a charging current of 6A or greater. For example, the current received by the individual battery cell from the charging device can be greater than 10A, greater than 15A, or greater than 20A. The greater the current received by the individual battery cell from the charging device, the shorter the time required for the individual battery cell to be fully charged, thereby saving users a significant amount of charging waiting time.

[0071] In some embodiments, when the interface 300 is electrically connected to the charging device 60, the individual battery cell 201 can be continuously charged at a 3C charging rate, and the charging time during the constant current charging phase is less than or equal to 20 minutes. For example, the charging time during the constant current charging phase of the individual battery cell at a 3C charging rate can be less than or equal to 15 minutes, less than or equal to 10 minutes, or less than or equal to 5 minutes. The shorter charging time required for the individual battery cell during the constant current charging phase reduces the overall charging time, allowing users to reduce charging waiting time.

[0072] In some embodiments, when the interface 300 is electrically connected to the charging device 60, the individual battery cell 201 can be continuously charged at a charging rate of 3C, and the ratio of the capacity charged by the individual battery cell 201 during the constant current charging phase to the nominal capacity of the individual battery cell 201 is greater than or equal to 80%. For example, the ratio is greater than or equal to 85%, greater than or equal to 90%, or greater than or equal to 95%. The large ratio of the capacity that the individual battery cell can be charged to its nominal capacity during the constant current charging phase results in a shorter charging time required for the individual battery cell, allowing users to reduce charging waiting time.

[0073] To enable the battery pack to support the operation of high-power power tools, when interface 300 is electrically connected to power tool 50, the continuous discharge rate of a single battery cell 201 to power tool 50 must be greater than or equal to 10C. Optionally, the continuous discharge rate of a single battery cell can reach 10C–20C or 20C–30C. For example, the continuous discharge rate of a single battery cell can be 10C, 15C, 17C, 20C, 23C, 25C, 28C, or 30C. When the continuous discharge rate of a single battery cell is within this range, the battery pack can support the operation of high-power power tools.

[0074] In some embodiments, the continuous discharge rate of the battery pack 10 is also greater than or equal to 10C. Optionally, the continuous discharge rate of the battery pack 10 can reach 10C to 20C or 20C to 30C.

[0075] The higher the continuous discharge rate of the battery pack, the higher the output power of the battery pack, the higher the power available to the power tools powered by the battery pack, and thus the higher the user's work efficiency.

[0076] In some embodiments, when the interface 300 is electrically connected to the power tool 50, the battery pack 10 provides a continuous output power of 700W or more to the power tool 50. Optionally, the continuous output power of the battery pack 10 is greater than or equal to 800W, or greater than or equal to 900W, or greater than or equal to 1000W, or greater than or equal to 1200W. Therefore, the battery pack is capable of outputting high power to the power tool to support the operation of high-power power tools.

[0077] In some embodiments, when the interface 300 is electrically connected to the power tool 50, and the battery pack 10 discharges to the power tool 50 at room temperature with a continuous discharge current of greater than or equal to 40A, the depth of discharge of the battery pack 10 is greater than or equal to 80%.

[0078] It should be noted that the depth of discharge (DoD) of a battery pack refers to the percentage of its nominal capacity released during a single discharge.

[0079] Therefore, the battery pack can support high current output, thereby improving the working efficiency of power tools, and the battery pack can also maintain a high depth of discharge when the high current output is applied, so that the battery pack can release more usable energy when discharging, thereby significantly extending the service life of power tools.

[0080] Research has revealed that high-rate charging and discharging significantly impacts the lifespan of individual battery cells. Specifically, taking lithium-ion cells as an example, during high-rate charging, the insertion rate of lithium ions at the negative electrode may not keep pace with the current demand, leading to the direct deposition of lithium metal and the formation of dendrites. These dendrites can puncture the separator, causing internal short circuits, resulting in capacity decay or even thermal runaway. During high-rate discharging, the rapid insertion and extraction of lithium ions in the positive electrode material causes lattice stress accumulation, generating microcracks. This leads to the shedding of active material, resulting in a decrease in the capacity of the individual battery cell.

[0081] Even after multiple high-rate charge-discharge cycles, the individual cells in the battery pack provided by this application can still retain most of their capacity, thereby improving the service life of the battery pack and reducing the user's operating costs.

[0082] In some embodiments, the individual cell 201 is charged at a continuous charging rate of 5C and discharged at a continuous discharging rate of 5C, and the capacity retention rate of the individual cell 201 is at least 75% after 3000 charge-discharge cycles.

[0083] It should be noted that the capacity retention rate of a single battery cell can be understood as the ratio between the actual capacity of a single battery cell after two charges and its rated capacity. As the number of charges of a single battery cell increases, the actual capacity of the single battery cell will decrease. The smaller the rate of decrease, the higher the capacity retention rate of the single battery cell, and thus the better the capacity retention performance of the single battery cell.

[0084] It should also be noted that when conducting life tests on individual battery cells, after charging is completed, the temperature is allowed to drop to room temperature before discharging, and after discharging is completed, the temperature is allowed to drop to room temperature before charging.

[0085] In some embodiments, the single cell 201 is charged at a continuous charging rate of 5C and discharged at a continuous discharging rate of 10C, and the capacity retention rate of the single cell 201 is at least 75% after 2000 charge-discharge cycles.

[0086] In some embodiments, the single cell 201 is charged at a continuous charging rate of 5C and discharged at a continuous discharging rate of 15C, and the capacity retention rate of the single cell 201 is at least 70% after 1600 charge-discharge cycles.

[0087] In some embodiments, such as Figure 4 As shown, the battery pack 10 also includes a locking part 120 for engaging with a corresponding locking member of the power tool 50 or charging device 60 to lock the battery pack 10 to the power tool 50 or charging device 60. In the left-right direction, the locking part 120 is located between a pair of guide rails 301, 302. The locking part 120 is operably movable between a locked position and an unlocked position to lock or unlock the battery pack 10 to the power tool 50 or charging device 60. In the illustrated embodiment, the locking part 120 is configured as a snap-fit. In other embodiments, the locking part may also be configured as a recess. Further, the battery pack 10 also includes an operating part 121, which operably drives the locking part 120 to move between the locked position and the unlocked position. Optionally, the operating part 121 is configured as a button, located at one end of the housing 100, and is integrally formed with the locking part 120. When it is necessary to remove the battery pack 10 from the power tool 50 or the charging device 60, press the operating part 121 to move the locking part 120 from the locked position to the unlocked position, and then move the battery pack 10 along the rear to remove the battery pack 10 from the power tool 50 or the charging device 60.

[0088] In some embodiments, such as Figure 7As shown, the battery cell assembly 200 further includes a bracket 230 for fixing individual battery cells 201. The bracket 230 includes at least one cylindrical wall 231, each cylindrical wall 231 enclosing a receiving cavity 233, in which each individual battery cell 201 is at least partially housed. The outer peripheral surface of each individual battery cell 201 is coupled to the receiving cavity 233 in a shape-matched manner. In some embodiments, the bracket 230 is made of a thermally conductive material, and each cylindrical wall 233 can cover at least 50% of the outer peripheral surface of the corresponding individual battery cell, so that the heat generated by the individual battery cell during operation can be better conducted by the bracket, which is beneficial to the heat dissipation of the individual battery cell.

[0089] In the illustrated embodiment, the support 230 includes a first support 230a and a second support 230b connected to each other. The first support 230a and the second support 230b respectively fix the two ends of the single battery cell 201 in the longitudinal direction. Specifically, the first support 230a and the second support 230b each include a plurality of first cylindrical walls 231a and a plurality of second cylindrical walls 231b. When the first support 230a and the second support 230b are connected, the first cylindrical walls 231a and the second cylindrical walls 231b are joined to form a cylindrical wall 231. It should be noted that the cylindrical wall may completely cover the circumference of a single battery cell, or it may only cover a portion of the circumference of a single battery cell. In other embodiments, the support may also be integrally formed.

[0090] In some embodiments, such as Figure 5 and Figure 6 As shown, the battery pack 10 also includes a circuit board 150, which is configured to electrically connect the terminal assembly 310 and the cell assembly 200. Specifically, the circuit board 150 is located above the bracket 230, and the terminal assembly 310 is soldered onto the circuit board 150. The circuit board 150 is used to control the charging and discharging of the battery pack 10.

[0091] In some embodiments, the cell assembly 200 further includes: a positive output terminal 210, electrically connected to the positive electrode of at least one individual cell 201, outputting a positive potential of the cell assembly 200; a negative output terminal 220, electrically connected to the negative electrode of at least one individual cell 201, outputting a negative potential of the cell assembly 200; a positive current-carrying plate 211, electrically connected between the positive output terminal 210 and the positive terminal 311; and a negative current-carrying plate 221, electrically connected between the negative output terminal 220 and the negative terminal 312.

[0092] This configuration allows the large current during charging and discharging to be transmitted directly through the positive and negative current carrier plates without going through the circuit board, thus avoiding the problem of excessive heat generation caused by the limited current transmission capacity of the circuit board.

[0093] Optionally, the width of the positive electrode current carrier 211 and / or the negative electrode current carrier 221 ranges from 7 to 10 mm. A larger width of the positive electrode current carrier and / or the negative electrode current carrier increases the current-carrying area and reduces the resistance of the positive electrode current carrier and / or the negative electrode current carrier, thereby reducing the heat generated by the current carrier and improving the safety and reliability of the battery pack. It should be noted that the width range of the positive electrode current carrier and / or the negative electrode current carrier refers to an optional range in the left-right direction. For ease of wiring layout, the terminal assembly 310, the positive electrode current carrier 211, and the negative electrode current carrier 221 are arranged on the same side of the circuit board 150. Specifically, the positive electrode current carrier 211 and the negative electrode current carrier 221 are located on the side of the circuit board 150 away from the individual battery cell 201.

[0094] In some embodiments, such as Figure 7 As shown, the circuit board 150 is provided with a positive electrode soldering hole 151, and the positive electrode current carrier 211 is soldered to the circuit board 150 through the positive electrode soldering hole 151. A positive electrode through hole 212 is provided on the positive electrode current carrier 211 at the position corresponding to the positive electrode soldering hole 151. The positive terminal 311 passes through the positive electrode through hole 212 and the positive electrode soldering hole 151 to achieve soldering with the circuit board 150. And / or, the circuit board 150 is provided with a negative electrode soldering hole 153, and the negative electrode current carrier 221 is soldered to the circuit board 150 through the negative electrode soldering hole 153. A negative electrode through hole 222 is provided on the negative electrode current carrier 221 at the position corresponding to the negative electrode soldering hole 153. The negative terminal 312 passes through the negative electrode through hole 222 and the negative electrode soldering hole 153 to achieve soldering with the circuit board 150. This configuration allows the positive and / or negative current-carrying plates to fit more tightly with their corresponding terminals, thereby increasing the contact area between the positive and / or negative current-carrying plates and their corresponding terminals, reducing internal resistance, and avoiding overheating caused by high-current charging and discharging.

[0095] In some embodiments, the battery pack 10 further includes a fuse 160, which is connected to the positive current-carrying plate 211 or the negative current-carrying plate 221. This facilitates the arrangement of the fuse and simplifies the wiring.

[0096] Specifically, the positive electrode current-carrying plate includes a first positive electrode segment and a second positive electrode segment, with a fuse connected between the first positive electrode segment and the second positive electrode segment; and / or, the negative electrode current-carrying plate includes a first negative electrode segment and a second negative electrode segment, with a fuse connected between the first negative electrode segment and the second negative electrode segment. In the illustrated embodiment, as... Figure 5 As shown, fuse 160 is connected between the first positive terminal 211a and the second positive terminal 211b.

[0097] In some embodiments, the cell assembly 200 further includes a connecting piece 240, through which multiple individual cells 201 are connected in series and / or in parallel.

[0098] In some embodiments, such as Figure 8 As shown, the connecting piece 240 includes: a first positive connecting piece 241 and a second positive connecting piece 242 that are interconnected and at least partially overlap in the longitudinal direction of a single cell 201. The first positive connecting piece 241 is electrically connected to the positive electrode of at least one single cell 201. The second positive connecting piece 242 includes a positive output terminal 210 connected to the circuit board 150, and the positive output terminal 210 outputs the positive potential of the cell assembly 200. It also includes a first negative connecting piece 243 and a second negative connecting piece 244 that are interconnected and at least partially overlap in the longitudinal direction of a single cell 201. The first negative connecting piece 243 is electrically connected to the negative electrode of at least one single cell 201. The second negative connecting piece 244 includes a negative output terminal 220 connected to the circuit board 150, and the negative output terminal 220 outputs the negative potential of the cell assembly 200.

[0099] During charging and discharging, a large current flows through the connector, causing it to heat up. By designing the connector to include at least two overlapping parts, the thickness of the connector is increased, thereby reducing resistance and heat generation, thus preventing the connector from overheating.

[0100] In some embodiments, the conductivity of the second positive electrode connector 242 is greater than that of the first positive electrode connector 241; and / or, the conductivity of the second negative electrode connector 244 is greater than that of the first negative electrode connector 243. Since the second positive electrode connector and the second negative electrode connector respectively comprise the positive output terminal of the output cell assembly's positive potential and the negative output terminal of the output cell assembly's negative potential, they require the passage of a large current, which may lead to severe heat generation. Increasing the conductivity reduces the resistance, thus reducing heat generation and preventing excessively high temperatures.

[0101] In some embodiments, such as Figure 8 As shown, the first positive electrode connecting piece 241 includes a first positive electrode welding portion 241a and a second positive electrode welding portion 241b, which are respectively welded to the positive electrodes of two individual battery cells 201a and 201b. The overlapping area of ​​the first positive electrode connecting piece 241 and the second positive electrode connecting piece 242 is located in the current path between the first positive electrode welding portion 241a and the second positive electrode welding portion 241b. And / or, the first negative electrode connecting piece 243 includes a first negative electrode welding portion 243a and a second negative electrode welding portion 243b, which are respectively welded to the positive electrodes of two individual battery cells 201c and 201d. The overlapping area of ​​the first negative electrode connecting piece 243 and the second negative electrode connecting piece 244 is located in the current path between the first negative electrode welding portion 243a and the second negative electrode welding portion 243b. This arrangement allows the overlapping area to be located in the path through which a large current flows, resulting in a larger cross-sectional area and lower resistance in this area, thereby preventing excessive temperature rise in this area.

[0102] It should be noted that the overlapping area of ​​the first positive electrode connecting piece 241 and the second positive electrode connecting piece 242 refers to the overlapping area of ​​the first positive electrode connecting piece 241 and the second positive electrode connecting piece 242 in the longitudinal direction (left and right direction in the figure) of the single cell 201, and the overlapping area of ​​the first negative electrode connecting piece 243 and the second negative electrode connecting piece 244 refers to the overlapping area of ​​the first negative electrode connecting piece 243 and the second negative electrode connecting piece 244 in the longitudinal direction (left and right direction in the figure) of the single cell 201.

[0103] Specifically, two individual battery cells 201a and 201b are arranged side-by-side in the vertical direction. The first positive electrode welding part 241a is welded to the positive electrode of the individual battery cell 201a, and the second positive electrode welding part 241b is welded to the positive electrode of the individual battery cell 201b. Two individual battery cells 201c and 201d are arranged side-by-side in the vertical direction. The first negative electrode welding part 243a is welded to the negative electrode of the individual battery cell 201c, and the second positive electrode welding part 243b is welded to the negative electrode of the individual battery cell 201d.

[0104] In some embodiments, such as Figure 5 and Figure 6 As shown, the second positive electrode connector 242 includes a positive electrode overlapping portion 242a located at one end of the cell assembly 200 along the longitudinal direction of the individual cell 201, and a positive electrode bending portion 242b arranged at an angle to the positive electrode overlapping portion 242a and the positive electrode output terminal 210. The positive electrode output terminal 210 is bent towards the circuit board 150 from the positive electrode bending portion 242b and connected to the circuit board 150. The second negative electrode connector 244 includes a negative electrode overlapping portion 244a located at the other end of the cell assembly 200 along the longitudinal direction of the individual cell 201, and a negative electrode bending portion 244b arranged at an angle to the negative electrode overlapping portion 244a and the negative electrode output terminal 220. The negative electrode output terminal 220 is bent towards the circuit board 150 from the negative electrode bending portion 244b and connected to the circuit board 150. Optionally, in the longitudinal direction of the single cell 201, the positive electrode overlapping portion 242a and the positive electrode bending portion 242b overlap with at least a portion of the first positive electrode connecting piece 241, and the negative electrode overlapping portion 244a and the negative electrode bending portion 244b overlap with at least a portion of the first negative electrode connecting piece 243. Optionally, the positive electrode bending portion 242b is substantially perpendicular to the positive electrode overlapping portion 242a and the positive electrode output terminal 210, and the negative electrode bending portion 244b is substantially perpendicular to the negative electrode overlapping portion 244a and the negative electrode output terminal 220.

[0105] In some embodiments, such as Figure 7 , Figure 10 and Figure 11As shown, the battery pack 10 also includes a temperature sensor 170. The circuit board 150 is configured to electrically connect the terminal assembly 310 and the cell assembly 200. The temperature sensor 170 is electrically connected to the circuit board 150. The temperature sensor 170 includes a flexible sheet 171 and a temperature-sensing block 172 attached to the flexible sheet 171. The temperature sensor 170 is configured to be sandwiched between two adjacent individual cells 201e and 201f, so that the temperature-sensing block 172 is in close contact with at least one individual cell 201e or 201f. This allows the temperature sensor to be in close contact with the individual cell being measured, enabling more accurate measurement of the individual cell's temperature, thereby improving the accuracy and reliability of individual cell temperature detection. It should be noted that "close contact between the temperature-sensing block and at least one individual cell" means that at least a portion of the temperature-sensing block can abut against the peripheral surface of at least one individual cell, allowing the temperature-sensing block to obtain an accurate temperature of the individual cell.

[0106] Specifically, a temperature sensor 170 extends from the side of the circuit board 150 near the cell assembly 200. A through hole 235 is provided on the bracket 230 corresponding to the position of the temperature sensor 170, and an opening 236 is provided between the adjacent cylindrical walls 231e and 231f that accommodate two adjacent individual cells 201e and 201f. The temperature sensor 170 passes through the through hole 235 and the temperature sensing block 172 is located in the opening 236, so that the temperature sensing block 172 is clamped between the two adjacent individual cells 201e and 201f. Optionally, the through hole 235 is provided on the first bracket 230a, and the temperature sensing block 172 is set as a thermistor.

[0107] This application also provides a battery pack 10 configured to power a power tool. The battery pack 10 includes: a housing 100; an interface 300 configured to be detachably connected to a power tool 50 or a charging device 60, the interface 300 including a terminal assembly 310, the terminal assembly 310 including a positive terminal 311 and a negative terminal 312, the positive terminal 311 and the negative terminal 312 being configured to electrically connect to corresponding terminals of the power tool 50 or the charging device 60 to realize the electrical connection between the battery pack 10 and the power tool 50 or the charging device 60; and a cell assembly 200 disposed within the housing 100 and electrically connected to the terminal assembly 310, including multiple interconnected individual cells 201, the individual cells 201 being cylindrical cells; when the interface 300 is electrically connected to the charging device 60, the individual cells 201 can receive a charging current greater than or equal to 6A.

[0108] With this configuration, the greater the current received by a single battery cell from the charging device, the shorter the time required for the single battery cell to be fully charged, thus saving users a significant amount of charging waiting time.

[0109] For details regarding the specific structure and performance parameters of battery pack 10, please refer to the appendix. Figures 1 to 11And the corresponding expressions mentioned above will not be repeated here.

[0110] This application also provides a battery pack 10 configured to power a power tool. The battery pack 10 includes: a housing 100; an interface 300 configured to be detachably connected to a power tool 50 or a charging device 60, the interface 300 including a terminal assembly 310, the terminal assembly 310 including a positive terminal 311 and a negative terminal 312, the positive terminal 311 and the negative terminal 312 being configured to electrically connect to corresponding terminals of the power tool 50 or the charging device 60 to realize the electrical connection between the battery pack 10 and the power tool 50 or the charging device 60; and a cell assembly 200 disposed within the housing 100 and electrically connected to the terminal assembly 310, including multiple interconnected individual cells 201, the individual cells 201 being cylindrical cells; when the interface 300 is electrically connected to the charging device 60, the individual cells 201 can be continuously charged at a charging rate of 3C and the charging time during the constant current charging phase is less than or equal to 20 minutes.

[0111] With this configuration, the charging time required for a single battery cell during the constant current charging phase is shorter, thereby reducing the total charging time and allowing users to reduce charging waiting time.

[0112] For details regarding the specific structure and performance parameters of battery pack 10, please refer to the appendix. Figures 1 to 11 And the corresponding expressions mentioned above will not be repeated here.

[0113] This application also provides a battery pack 10 configured to power a power tool 50. The battery pack 10 includes: a housing 100; and an interface 300 configured to be detachably connected to the power tool 50 or a charging device 60. The interface 300 includes a terminal assembly 310, which includes a positive terminal 311 and a negative terminal 312. The positive terminal 311 and the negative terminal 312 are configured to electrically connect to corresponding terminals of the power tool 50 or the charging device 60 to realize the battery pack 10. Electrical connection to power tool 50 or charging device 60; battery cell assembly 200, disposed within housing 100 and electrically connected to terminal assembly 310, comprising multiple interconnected individual battery cells 201, each individual battery cell 201 being a cylindrical battery cell; when interface 300 is electrically connected to charging device 60, each individual battery cell 201 can be continuously charged at a charging rate of 3C and the ratio of the capacity charged into the individual battery cell 201 during the constant current charging phase to the nominal capacity of the individual battery cell 201 is greater than or equal to 80%.

[0114] With this configuration, the capacity that a single battery cell can be charged during the constant current charging phase is a larger proportion of its nominal capacity, resulting in a shorter charging time for each battery cell and allowing users to reduce charging waiting time.

[0115] For details regarding the specific structure and performance parameters of battery pack 10, please refer to the appendix. Figures 1 to 11 And the corresponding expressions mentioned above will not be repeated here.

[0116] This application also provides a battery pack 10 configured to power a power tool 50. The battery pack 10 includes: a housing 100; an interface 300 configured to be detachably connected to the power tool 50 or a charging device 60, the interface 300 including a terminal assembly 310, the terminal assembly 310 including a positive terminal 311 and a negative terminal 312, the positive terminal 311 and the negative terminal 312 being configured to electrically connect to corresponding terminals of the power tool 50 or the charging device 60 to achieve electrical connection between the battery pack 10 and the power tool 50 or the charging device 60; and a cell assembly 200 disposed within the housing 100, including multiple interconnected individual cells 201, each cell 201 being a cylindrical cell, the cell assembly 200 being configured to be electrically connected to the terminal assembly 310; the individual cells 201 being charged at a continuous charging rate of 5C and discharged at a continuous discharging rate of 5C, and after 3000 charge-discharge cycles, the capacity retention rate of the individual cells 201 is at least 75%.

[0117] Even after multiple high-rate charge-discharge cycles, the individual cells in the battery pack provided by this application can still retain most of their capacity, thereby improving the service life of the battery pack and reducing the user's operating costs.

[0118] For details regarding the specific structure and performance parameters of battery pack 10, please refer to the appendix. Figures 1 to 11 Furthermore, the technical features corresponding to the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should all be considered to be within the scope of this specification.

[0119] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A battery pack (10) configured to power a power tool (50), characterized in that, include: Casing (100); An interface (300) is configured to be detachably connected to the power tool (50) or charging device (60), the interface (300) including a terminal assembly (310) including a positive terminal (311) and a negative terminal (312), the positive terminal (311) and the negative terminal (312) being configured to electrically connect to corresponding terminals of the power tool (50) or charging device (60) to achieve electrical connection between the battery pack (10) and the power tool (50) or charging device (60); A cell assembly (200) is disposed within the housing (100) and includes multiple interconnected individual cells (201), wherein each individual cell (201) is a cylindrical cell, and the cell assembly (200) is configured to be electrically connected to the terminal assembly (310); The single cell (201) is charged at a continuous charging rate of 5C and discharged at a continuous discharging rate of 5C, and after 3000 charge-discharge cycles, the capacity retention rate of the single cell (201) is at least 75%.

2. The battery pack (10) according to claim 1, characterized in that, The single cell (201) is charged at a continuous charging rate of 5C and discharged at a continuous discharging rate of 10C, and after 2000 charge-discharge cycles, the capacity retention rate of the single cell (201) is at least 75%.

3. The battery pack (10) according to any one of claims 1-2, characterized in that, The single cell (201) is charged at a continuous charging rate of 5C and discharged at a continuous discharging rate of 15C, and after 1600 charge-discharge cycles, the capacity retention rate of the single cell (201) is at least 70%.

4. The battery pack (10) according to claim 1, characterized in that, When the interface (300) is electrically connected to the power tool (50), and the battery pack (10) discharges to the power tool (50) at room temperature with a continuous discharge current of greater than or equal to 40A, the depth of discharge of the battery pack (10) is greater than or equal to 80%.

5. The battery pack (10) according to claim 1, characterized in that, When the interface (300) is electrically connected to the power tool (50), the battery pack (10) outputs a power greater than 700W to the power tool (50).

6. The battery pack (10) according to claim 1, characterized in that, When the interface (300) is electrically connected to the power tool (50), and the single cell (201) discharges to the power tool (50) at a continuous discharge rate of greater than or equal to 10C at room temperature, the depth of discharge of the single cell (201) is greater than or equal to 95%.

7. The battery pack (10) according to claim 1, characterized in that, When the interface (300) is electrically connected to the power tool (50), the single battery cell (201) discharges to the power tool (50) at a continuous discharge rate of 10C at room temperature, and the temperature rise of the single battery cell (201) does not exceed 48K when the discharge is completed.

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