High rate lithium iron phosphate battery

Abstract

The utility model discloses a high rate lithium iron phosphate battery pack, including metal shell and electric core group, electric core group sets up in metal shell, the number of electric core group is set to eight, and eight electric core group is mutually connected in series, every electric core group includes eight high rate lithium iron phosphate electric core that parallelly connects each other. The battery pack uses lithium iron phosphate electric core, and it has the advantages of high energy density, long cycle life, low maintenance cost and the like; and it uses sixty -four high rate lithium iron phosphate electric core, wherein eight high rate lithium iron phosphate electric core is parallelly connected and forms an electric core group, and then eight electric core groups are connected in series, effectively improve the charge, discharge rate of battery pack, satisfy the demand of the automatic handling car system usually needs fast charging, and use metal shell to reduce the overall volume of battery pack.

Description

Technical Field

[0001] This utility model relates to the field of batteries, and in particular to a high-rate lithium iron phosphate battery pack. Background Technology

[0002] Automated Guided Vehicle (AGV) systems have developed into one of the largest specialized branches of production logistics systems, becoming an indispensable and important component of modern enterprise automation equipment. The requirements for these devices are increasingly stringent, demanding high strength, long service life, heavy load capacity, stable performance, high degree of automation and intelligence, low noise and pollution-free operation, and suitability for both indoor and outdoor use. Currently, many AGV systems on the market use traditional lead-acid batteries and conventional lithium battery packs as their power source. Traditional lead-acid batteries used in AGVs suffer from drawbacks such as low energy density, large size, short cycle life (300-500 cycles), long charging time, high self-discharge rate, and high maintenance costs. Conventional lithium battery packs can only be charged at a 0.5C rate and discharged at a 1C rate, affecting operational efficiency. Utility Model Content

[0003] This invention provides a high-rate lithium iron phosphate battery pack, aiming to solve the problems in the prior art.

[0004] This utility model discloses a high-rate lithium iron phosphate battery pack, including a metal casing and a cell assembly. The cell assembly is disposed inside the metal casing, and the number of the cell assemblies is set to eight, with the eight cell assemblies connected in series. Each cell assembly includes eight high-rate lithium iron phosphate cells connected in parallel.

[0005] In some embodiments, each of the high-rate lithium iron phosphate cells has a charging rate of 20C and a capacity of 2.5Ah.

[0006] In some embodiments, the high-rate lithium iron phosphate battery pack further includes a molded bracket disposed within the metal casing, and the battery cell assembly is disposed in the molded bracket; the molded bracket includes a top seat and a base, the top end of the battery cell assembly contacts the top seat, and the bottom end of the battery cell assembly contacts the base.

[0007] In some embodiments, the forming support is configured as an upper support and a lower support stacked on top of each other; wherein, four of the battery cell groups are disposed in the upper support, and the remaining four of the battery cell groups are disposed in the lower support.

[0008] In some embodiments, the high-rate lithium iron phosphate battery pack further includes a fixing screw disposed on the outside of the cell pack, and threaded holes are provided on both the upper bracket and the lower bracket, with the fixing screw passing through the threaded holes of both the upper bracket and the lower bracket.

[0009] In some embodiments, the high-rate lithium iron phosphate battery pack further includes an epoxy fiberglass board disposed within the metal casing, the epoxy fiberglass board being disposed around the cell group and between the upper cell group and the lower cell group; wherein, the four cell groups disposed on the upper support are the upper cell groups, and the four cell groups disposed in the lower support are the lower cell groups.

[0010] In some embodiments, the high-rate lithium iron phosphate battery pack further includes a PCBA fixing plate, a PCBA protection plate, and a voltage acquisition line; the PCBA fixing plate is fixedly disposed on the top of the molding bracket, the PCBA protection plate is fixedly disposed on the PCBA fixing plate, the PCBA protection plate is used to mount the PCBA, and the voltage acquisition line connects the PCBA and the cell pack.

[0011] In some embodiments, the high-rate lithium iron phosphate battery pack further includes kilobar paper and EVA; the kilobar paper is attached to the top of the molding bracket; the EVA is attached to the kilobar paper and is located between the kilobar paper and the PCBA fixing plate.

[0012] In some embodiments, the high-rate lithium iron phosphate battery pack further includes a top cover, a positive terminal, and a negative terminal; the top cover is disposed on the top of the metal casing, the positive terminal and the negative terminal are disposed on the top cover, and the top cover has through holes at the positions where the positive terminal and the negative terminal are disposed, so that the interior of the positive terminal and the negative terminal can be connected to the cell pack.

[0013] In some embodiments, the high-rate lithium iron phosphate battery pack further includes a flat positive copper busbar, which connects the positive electrode of the battery cell pack to the positive terminal.

[0014] The beneficial effects of this utility model are as follows: This utility model discloses a high-rate lithium iron phosphate battery pack, comprising a metal casing and a cell assembly. The cell assembly is disposed within the metal casing, and the number of cell assemblies is set to eight, with the eight cell assemblies connected in series. Each cell assembly includes eight high-rate lithium iron phosphate cells connected in parallel. Using lithium iron phosphate cells offers advantages such as high energy density, long cycle life, and low maintenance costs. Furthermore, by using sixty-four high-rate lithium iron phosphate cells, with eight high-rate lithium iron phosphate cells connected in parallel to form a cell assembly, and then connecting these eight cell assemblies in series, the charge and discharge rates of the battery pack are effectively improved, meeting the rapid charging requirements typically needed by automated guided vehicle (AGV) systems. The use of a metal casing reduces the overall size of the battery pack. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 Exploded view of the structure of the high-rate lithium iron phosphate battery pack provided in this embodiment of the utility model;

[0017] Figure 2 for Figure 1 A magnified view of part A of the high-rate lithium iron phosphate battery pack shown.

[0018] Figure 3 for Figure 1 A magnified view of part B of the high-rate lithium iron phosphate battery pack shown.

[0019] Figure 4 A graph showing the voltage variation over time during charging of a high-rate lithium iron phosphate battery pack provided in this embodiment of the utility model.

[0020] Figure 5 The graph shows the voltage change over time during discharge of the high-rate lithium iron phosphate battery pack provided in this embodiment of the utility model.

[0021] Reference numerals: 1. Metal casing; 2. Battery cell assembly; 3. Molded bracket; 31. Upper bracket; 311. Second top mount; 312. Second base; 32. Lower bracket; 321. First top mount; 322. First base; 4. Fixing screw; 5. Epoxy fiberglass board; 6. PCBA fixing plate; 7. PCBA protection board; 8. Voltage acquisition line; 9. Quick-release paper; 10. EVA; 11. Top cover; 12. Positive terminal; 13. Negative terminal; 14. Positive copper busbar; 15. Handle; 16. Screw; 17. Insulating sleeve. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0023] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and, or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and, or collections thereof.

[0024] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0025] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0026] It should also be further understood that the terms "and" and "or" as used in this specification and the appended claims refer to any combination of one or more of the associated listed items and all possible combinations, and include such combinations.

[0027] like Figure 1As shown in the figure, this utility model embodiment discloses a high-rate lithium iron phosphate battery pack, including a metal casing 1 and a cell group 2. The cell group 2 is disposed inside the metal casing 1, and the number of the cell groups 2 is set to eight, and the eight cell groups 2 are connected in series with each other. Each cell group 2 includes eight high-rate lithium iron phosphate cells connected in parallel with each other.

[0028] In this embodiment, the high-rate lithium iron phosphate battery pack can be applied in an automated guided vehicle (AGV) system. This high-rate lithium iron phosphate battery pack uses a lithium iron phosphate system, which has advantages such as high energy density, long cycle life, and low maintenance costs. Furthermore, by using sixty-four high-rate lithium iron phosphate cells, the charge and discharge rates of the battery pack are increased, meeting the rapid charging requirements typically needed by AGV systems, thereby reducing downtime and significantly improving work efficiency. Specifically, eight high-rate lithium iron phosphate cells are connected in parallel to form a cell group 2, and eight cell groups 2 are connected in series to form the high-rate lithium iron phosphate battery pack. The metal casing 1 is integrally molded and can be a square metal casing with an opening at the top. It is blackened to ensure the insulation of the metal casing 1 and provide reliable safety protection. In the design of automated guided vehicles, the metal casing 1 provides a robust casing and protective device for the battery pack to prevent damage to the battery pack from external forces such as collisions and compression. At the same time, it ensures the normal operation of the battery pack in harsh environments such as high temperature, low temperature, and humidity, thereby improving the overall safety of the system. Using the metal casing 1 can reduce the size of the battery pack, improve the durability of the battery pack, and adapt to harsh operating environments.

[0029] See also Figure 4 and Figure 5 Specifically, each of the high-rate lithium iron phosphate cells has a charging rate of 20C and a capacity of 2.5Ah. The rated voltage of each high-rate lithium iron phosphate cell is 3.0V. The high-rate lithium iron phosphate battery pack, composed of sixty-four high-rate lithium iron phosphate cells, has a rated voltage of 25.6V and a capacity of 20Ah. This high-rate lithium iron phosphate battery pack can continuously operate at a 3C charging and discharging rate, significantly improving battery efficiency compared to conventional lithium battery packs which can only be charged at a 0.5C rate and discharged at a 1C rate.

[0030] In other embodiments, this high-rate lithium iron phosphate battery pack can also be used in automotive starting power supplies, UPS (Uninterruptible Power Supply) backup power supplies, golf carts, power station energy storage systems, and other fields.

[0031] In some embodiments, the high-rate lithium iron phosphate battery pack further includes a molded bracket 3 disposed within the metal casing 1, and the battery cell assembly 2 is disposed in the molded bracket 3; the molded bracket 3 includes a top seat and a base, the top end of the battery cell assembly 2 contacts the top seat, and the bottom end of the battery cell assembly 2 contacts the base.

[0032] In this embodiment, the molding bracket 3 can better fix multiple high-rate lithium iron phosphate cells. The molding bracket 3 only includes a top seat and a base, that is, there is no additional surrounding plate between the top seat and the base, so that the gap between the top seat and the base is large enough to ensure that the cell group 2 can dissipate heat from the gap between the top seat and the base of the molding bracket 3, thereby ensuring the safety performance of the battery group. The integrated molding bracket 3 can also meet the requirements of automated welding production for battery assembly.

[0033] In some embodiments, the forming support 3 is configured as an upper support 31 and a lower support 32 stacked on top of each other; wherein, four of the battery cell groups 2 are disposed in the upper support 31, and the remaining four of the battery cell groups 2 are disposed in the lower support 32.

[0034] In this embodiment, the upper support 31 or the lower support 32 is a 4×8 molded support 3, meaning that one layer of the support can accommodate thirty-two high-rate lithium iron phosphate cells, and the upper support 31 and the lower support 32 can accommodate a total of sixty-four high-rate lithium iron phosphate cells. By setting the molded support 3 in the form of an upper support 31 and a lower support 32, the horizontal area occupied by the molded support 3 can be reduced, thereby reducing the length or width of the high-rate lithium iron phosphate battery pack.

[0035] The lower support 32 includes a first base 322 and a first top seat 321. The upper support 31 includes a second base 312 and a second top seat 311, with the bottom end of the second base 312 stacked on top of the first top seat 321.

[0036] In some embodiments, the high-rate lithium iron phosphate battery pack further includes a fixing screw 4 disposed on the outside of the cell group 2. Both the upper bracket 31 and the lower bracket 32 ​​are provided with threaded holes, and the fixing screw 4 passes through the threaded holes of the upper bracket 31 and the lower bracket 32.

[0037] In this embodiment, multiple fixing screws 4 can be provided, which are spaced apart along the side of the molding bracket 3. The fixing screws 4 are used to connect the upper bracket 31 and the lower bracket 32 ​​to ensure the stability of the connection between the upper bracket 31 and the lower bracket 32. On the other hand, they are used to limit the position of the cell group 2 to prevent the cell group 2 from coming out of the gap between the top seat and the base of the molding bracket 3 due to accidental circumstances. Thus, the structural stability of the high-rate lithium iron phosphate battery pack is guaranteed from the above two aspects.

[0038] See also Figure 2 In some embodiments, the high-rate lithium iron phosphate battery pack further includes an epoxy fiberglass board 5 disposed within the metal casing 1. The epoxy fiberglass board 5 is disposed around the cell group 2 and between the upper cell group 2 and the lower cell group 2. The four cell groups 2 disposed on the upper support 31 are the upper cell groups 2, and the four cell groups 2 disposed in the lower support 32 are the lower cell groups 2.

[0039] In this embodiment, the epoxy fiberglass board 5 comprises two parts. One part is disposed around the battery cell assembly 2, which can be formed by four rectangular epoxy fiberglass boards 5 joined together. The battery cell assembly 2 and the forming bracket 3 are disposed in the space between the four epoxy fiberglass boards 5. The other part is disposed between the upper battery cell assembly 2 and the lower battery cell assembly 2, specifically between the bottom end of the second base 312 and the top end of the first top seat 321. The epoxy fiberglass board 5 serves to insulate and protect the internal battery cell assembly 2.

[0040] In some embodiments, the high-rate lithium iron phosphate battery pack further includes a PCBA fixing plate 5, a PCBA protection plate 6, and a voltage acquisition line 8; the PCBA fixing plate 5 is fixedly disposed on the top of the molding bracket 3, the PCBA protection plate 6 is fixedly disposed on the PCBA fixing plate 5, the PCBA protection plate 6 is used to set the PCBA, and the voltage acquisition line 8 connects the PCBA and the cell pack 2.

[0041] In this embodiment, the PCBA fixing plate 5 is fixedly mounted on the top of the second top seat 311, and the PCBA protection plate 6 is fixedly mounted on the upper surface of the PCBA fixing plate 5. The PCBA fixing plate 5 also has protrusions on opposite sides for limiting the position of the PCBA protection plate 6. The PCBA fixing plate 5 can improve the stability of the PCBA and prevent damage to the PCBA caused by vibration in AGV usage scenarios. The voltage acquisition line 8 is used to realize the electrical connection between the PCBA and the cell group 2. By acquiring the voltage of the cell group 2, the PCBA can accurately control the charging and discharging energy of the cell group 2, realizing overcharge and over-discharge protection and battery balancing functions. The PCBA includes two independently controlled MOS groups as charging switches and two independently controlled MOS groups as discharging switches, operating in full-duplex mode, which can better protect the safety of the battery and enable the high-rate lithium iron phosphate battery group to pass IEC certification testing.

[0042] In some embodiments, the high-rate lithium iron phosphate battery pack further includes a kibbling paper 9 and an EVA 10; the kibbling paper 9 is attached to the top of the molding bracket 3; the EVA 10 is attached to the kibbling paper 9 and is located between the kibbling paper 9 and the PCBA fixing plate 5.

[0043] In this embodiment, the PVC paper 9 is attached to the upper surface of the second top seat 311 of the upper support 31, serving as an insulating and protective layer. EVA10 (Ethylene-Vinyl Acetate Copolymer) is attached to the PVC paper 9, and the bottom surface of the PCBA fixing plate 5 is placed on the EVA10, which serves as an insulating and heat-insulating layer.

[0044] In some embodiments, the high-rate lithium iron phosphate battery pack further includes a top cover 11, a positive terminal 12, and a negative terminal 13; the top cover 11 is disposed on the top of the metal casing 1, the positive terminal 12 and the negative terminal 13 are disposed on the top cover 11, and the top cover 11 has through holes at the positions where the positive terminal 12 and the negative terminal 13 are disposed, so that the interior of the positive terminal 12 and the negative terminal 13 can be connected to the cell assembly 2.

[0045] In this embodiment, after the high-rate lithium iron phosphate battery pack portion inside the metal casing 1 is assembled and placed into the metal casing 1, the top cover 11 is assembled and sealed to the metal casing 1 using screws. Sealant is applied to the screw locations to achieve waterproofing, meeting the IP54 protection standard. The positive terminal 12 is made of brass to improve conductivity and is internally connected to the positive terminal of the cell assembly 2. The negative terminal 13 is also made of brass to improve conductivity and is internally connected to the negative terminal of the cell assembly 2. When using a high-rate lithium iron phosphate battery pack externally, since the positive terminal 12 and negative terminal 13 are internally connected to the cell assembly 2, they can output voltage and energy to the electrical equipment through the positive terminal 12 and negative terminal 13.

[0046] In some embodiments, the high-rate lithium iron phosphate battery pack further includes a flat positive copper busbar 14, which connects the positive electrode of the cell pack 2 to the positive terminal 12.

[0047] In this embodiment, the positive electrode copper busbar 14 is also disposed inside the metal casing 1, that is, it is assembled with other components before being placed into the metal casing 1. One end of the positive electrode copper busbar 14 is the positive electrode of the cell assembly 2, and the other end is connected to the inside of the positive terminal 12. The positive electrode copper busbar 14 is convenient for production and assembly. The positive electrode copper busbar 14 is flat, which can save internal space of the metal casing 1. The positive electrode copper busbar 14 has good conductivity, which can meet the high-rate charging and discharging requirements of high-rate lithium iron phosphate battery packs.

[0048] See also Figure 3 In some embodiments, the high-rate lithium iron phosphate battery pack further includes a handle 15, a screw 16, and an insulating sleeve 17. The handle 15 is rotatably connected to the top cover 11, facilitating the handling of the high-rate lithium iron phosphate battery pack by personnel. The screw 16 is used to tightly connect the positive terminal 12 to the external power line, and the negative terminal 13 to the external power line, thereby reducing contact resistance, enhancing conductivity, and preventing overheating caused by loose connections between the positive and negative terminals 12 and 13. Specifically, the screw 16 can be an M6 hexagonal screw. When connecting to the external power line, the external power line can be wound around the M6 ​​hexagonal screw corresponding to the positive and negative terminals 12 and 13, and then the M6 ​​hexagonal screw can be rotated to ensure a tight connection between the external power line and the positive and negative terminals 12 and 13. The insulating sleeve 17 is used to cover the M6 ​​hexagonal screw 16 to provide insulation protection.

[0049] Other performance parameters of this high-rate lithium iron phosphate battery pack are as follows:

[0050] Internal resistance ≤30mΩ;

[0051] Charging current ≤60A;

[0052] The maximum continuous current is 60A / 120A for 5 seconds.

[0053] Temperature range: charging temperature: 0℃~45℃; discharging temperature: -20℃~60℃.

[0054] The above are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A high-rate lithium iron phosphate battery pack, characterized in that, It includes a metal casing and a battery cell assembly, wherein the battery cell assembly is disposed inside the metal casing, and the number of the battery cell assemblies is set to eight, and the eight battery cell assemblies are connected in series with each other. Each battery cell assembly includes eight high-rate lithium iron phosphate cells connected in parallel with each other.

2. The high-rate lithium iron phosphate battery pack according to claim 1, characterized in that, Each of the high-rate lithium iron phosphate cells has a charging rate of 20C and a capacity of 2.5Ah.

3. The high-rate lithium iron phosphate battery pack according to claim 2, characterized in that, It also includes a molded bracket disposed within the metal casing, wherein the battery cell assembly is disposed within the molded bracket; the molded bracket includes a top seat and a base, wherein the top end of the battery cell assembly contacts the top seat and the bottom end of the battery cell assembly contacts the base.

4. The high-rate lithium iron phosphate battery pack according to claim 3, characterized in that, The forming support is configured as an upper support and a lower support stacked on top of each other; wherein, four of the battery cell groups are arranged in the upper support, and the remaining four of the battery cell groups are arranged in the lower support.

5. The high-rate lithium iron phosphate battery pack according to claim 4, characterized in that, It also includes a fixing screw disposed on the outside of the battery cell assembly. Both the upper bracket and the lower bracket are provided with threaded holes, and the fixing screw passes through the threaded holes of both the upper bracket and the lower bracket.

6. The high-rate lithium iron phosphate battery pack according to claim 4, characterized in that, It also includes an epoxy fiberglass board disposed within the metal casing, the epoxy fiberglass board being disposed around the battery cell assembly and between the upper battery cell assembly and the lower battery cell assembly; wherein, the four battery cell assemblies disposed on the upper support are the upper battery cell assemblies, and the four battery cell assemblies disposed in the lower support are the lower battery cell assemblies.

7. The high-rate lithium iron phosphate battery pack according to claim 3, characterized in that, It also includes a PCBA fixing plate, a PCBA protection plate, and a voltage acquisition line; the PCBA fixing plate is fixedly mounted on the top of the molding bracket, the PCBA protection plate is fixedly mounted on the PCBA fixing plate, the PCBA is mounted on the PCBA protection plate, and the voltage acquisition line connects the PCBA and the battery cell assembly.

8. The high-rate lithium iron phosphate battery pack according to claim 7, characterized in that, It also includes kraft paper and EVA; the kraft paper is attached to the top of the molding bracket; the EVA is attached to the kraft paper and is located between the kraft paper and the PCBA fixing plate.

9. The high-rate lithium iron phosphate battery pack according to claim 1, characterized in that, It also includes a top cover, a positive terminal, and a negative terminal; the top cover is disposed on the top of the metal casing, the positive terminal and the negative terminal are disposed on the top cover, and the top cover has through holes at the positions where the positive terminal and the negative terminal are disposed, so that the interior of the positive terminal and the negative terminal can be connected to the battery cell assembly.

10. The high-rate lithium iron phosphate battery pack according to claim 9, characterized in that, It also includes a flat positive copper busbar, which connects the positive electrode of the battery cell assembly to the positive terminal.

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