A low temperature resistant lithium battery module

Abstract

The present invention belongs to the field of battery technology, and specifically relates to a low-temperature resistant lithium battery module, comprising a shell layer, a temperature control structure and a battery pack, wherein the battery pack and the temperature control structure are installed inside the shell layer, and the battery cell group is composed of a plurality of battery cell groups connected in series and composed of battery cells connected in parallel, and a detection circuit is provided at the connection of each battery cell group, and the detection circuit and the temperature control structure are electrically connected to a computing terminal. The advantage of the present invention is that under low temperature conditions, a liquid control board absorbs cold air around the battery cell group and transmits it to the liquid inside the liquid control pipeline, which flows to the liquid control board, and a spherical capsule layer outside the liquid control board exchanges heat with the liquid inside the liquid control pipeline, so that the phase change material inside the phase change particles solidifies to store the cold air, thereby preventing the battery from being affected by the low temperature.

Description

Technical Field

[0001] The invention belongs to the technical field of batteries, and in particular relates to a low-temperature resistant lithium battery module. Background Art

[0002] Lithium batteries can only greatly improve their output power and energy recovery when the temperature is between 25℃ and 35℃. The battery is heated from a high-cold state to 20-35℃, and the power required is supplied by the battery itself, so it will greatly affect the overall battery life. For short distances, the overall battery life will drop more significantly due to the multiple activations of the battery pack temperature control system. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, the present invention provides a low-temperature resistant lithium battery module to solve the problems of reduced energy storage due to reduced battery activity at low temperatures and short circuit caused by temperature fluctuations in the prior art.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] A low temperature resistant lithium battery module, comprising a shell, a temperature control structure and a battery pack, wherein the battery pack and the temperature control structure are installed inside the shell, the battery pack is composed of a plurality of battery cell groups connected in parallel and connected in series, a detection circuit is provided at the connection of each battery cell group, and the detection circuit and the temperature control structure are electrically connected to a computing terminal;

[0006] The shell layer includes an upper shell, a lower shell, a main frame and a side guard plate. The outer side of the upper shell is provided with an embedded skirt, the inner wall of the embedded skirt is embedded with the outer wall of the lower shell, and both ends of the upper shell and the lower shell are provided with protrusions. The main frame is arranged at the bottom of the battery pack to fix the connection between it and the temperature control structure, and the side guard plate is arranged on the outer side of the battery pack to fix its series structure;

[0007] The temperature control structure includes a hydraulic control pipeline, a hydraulic control board, and a temperature assistant. The hydraulic control pipeline is conductively connected to the hydraulic control board and the temperature assistant. The hydraulic control board is in contact with the surface of the battery cell group. A ceramic plate is provided on the outside of the hydraulic control board. A spherical capsule layer is wrapped on the hydraulic control pipeline.

[0008] Furthermore, the temperature assistant is electrically connected to the battery cell group.

[0009] Furthermore, the spherical capsule layer includes a shell tube, the shell tube is filled with phase change particles, and the phase change particles are encapsulated in polyethylene spheres by phase change materials.

[0010] Furthermore, the shell tube is in a hollow cylindrical or rectangular shape.

[0011] Furthermore, carbon nanotubes or nano metal powder or nano wires are added to the phase change material.

[0012] Furthermore, the battery cell group includes a battery cell shell, a packaging layer, and an insulating layer. The battery cells are arranged in parallel inside the battery cell shell, the packaging layer is arranged between the battery cell shell and the battery cells, and the insulating layer is sandwiched between the packaging layer and the battery cells.

[0013] Furthermore, a series connection controller is provided outside the battery cell group, and the series connection controller includes a detection connector and a series connection board. The detection connector is connected to the detection circuit, and the series connection board connects multiple battery cell groups in series.

[0014] Furthermore, the detection circuit includes four switches S1, S2, S3, S4 and diodes D1, D2, D3, D4, and the diodes D1, D2, D3, D4 are connected in parallel with the corresponding switches S1, S2, S3, S4.

[0015] Furthermore, the detection circuit also includes measuring devices M1, M2, M3, measuring resistors SH1, SH2 and resistors R1, R2, R3, wherein the first resistor of the resistors is related to the positive reference voltage, and the second resistor and the third resistor of the resistors have the same resistance value.

[0016] Furthermore, the detection circuit further includes short-circuit resistors SG1 and SG2, wherein the two short-circuit resistors SG1 and SG2 are grounded, and wherein the two short-circuit resistors SG1 and SG2 are connected to the battery voltage Vbat.

[0017] Furthermore, the resistance values ​​of the resistors R1, R2, and R3 are higher than the resistance values ​​of the measuring resistors SH1 and SH2.

[0018] Furthermore, the short-circuit resistors SG1 and SG2 are high-resistance when not short-circuited, and the directions of the currents passing through the measuring resistors SH1 and SH2 have different polarity signs.

[0019] Further, the measuring device is used to measure whether there is a difference between the currents flowing through the measuring resistors SH1 and SH2 in the mode, and the resistance value of at least one of the short-circuit resistors SG1 and SG2 becomes smaller during the measurement.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] Under low temperature conditions, the liquid control board absorbs the cold air around the battery cell group and transmits it to the liquid inside the liquid control pipeline, which flows to the liquid control board. The spherical capsule layer outside the liquid control board exchanges heat with the liquid inside the liquid control pipeline, so that the phase change material inside the phase change particles solidifies to store the cold energy, thereby preventing the battery from being affected by low temperature. When the temperature of the battery cell group rises, the phase change material inside the phase change particles liquefies and transmits the cold energy to the liquid control board through the liquid control pipeline, thereby reducing the temperature of the battery cell group and achieving the effect of shifting peaks and filling valleys. The advantage of this structure is that the temperature control structure can adjust the battery temperature by itself through external temperature changes in non-extreme environments, without the need for external power supply, thereby reducing battery life;

[0022] When the resistance of resistors SG1, SG2, SB1, and SB2 becomes smaller, incorrect power-on of the battery pack is detected. The detection circuit can accurately detect the working status of the battery cells under abnormal temperature or collision conditions, avoiding overall failure caused by short circuit of a single battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of an exploded three-dimensional structure of an embodiment of a low-temperature resistant lithium battery module of the present invention;

[0024] Figure 2 for Figure 1 A schematic diagram of the local enlarged structure at the X in the middle;

[0025] Figure 3 A schematic diagram of the partial decomposition structure of a low-temperature resistant lithium battery module embodiment of the present invention Figure 1 ;

[0026] Figure 4 This is a schematic diagram of a detection circuit in an embodiment of a low-temperature resistant lithium battery module of the present invention;

[0027] Figure 5 A schematic diagram of a spherical capsule layer of a part of an embodiment of a low-temperature-resistant lithium battery module of the present invention;

[0028] Figure 6 A schematic diagram of the partial decomposition structure of a low-temperature resistant lithium battery module embodiment of the present invention Figure 2 ;

[0029] Figure 7 for Figure 6 A schematic diagram of the local enlarged structure at Y in the middle;

[0030] The reference numerals in the drawings of the specification include:

[0031] Shell layer 1, upper shell 10, lower shell 100, interlocking skirt 101, protrusion 102, main frame 11, side guard plate 12, temperature control structure 2, spherical capsule layer 20, shell tube 200, phase change particles 2000, hydraulic control pipeline 21, hydraulic control board 22, temperature assistant 23, ceramic board 24, battery pack 3, battery cell 30, battery cell group 300, battery cell shell layer 301, packaging layer 302, insulating layer 303, series connection controller 304, detection connector 305, series connection board 306, detection circuit 4, computing terminal 40. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the present invention, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments:

[0033] It should be noted that the same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0034] In addition, the descriptions of "first", "second", etc. in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0035] In the description of the present invention, unless otherwise clearly specified and limited, if the term "connection" or the like appears to indicate the connection relationship between components, the term should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two components or the interaction relationship between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention. Example

[0036] like Figure 1-Figure 7 As shown, a low-temperature resistant lithium battery module includes a shell 1, a temperature control structure 2 and a battery pack 3. The battery pack 3 and the temperature control structure 2 are installed inside the shell 1. The battery pack 3 is composed of a plurality of battery cell groups 300 connected in series, each battery cell group 300 is provided with a detection circuit 4 at the connection. The detection circuit 4 and the temperature control structure 2 are electrically connected to a computing terminal 40. The detection circuit 4 is electrically connected to the battery cell group 300. The detection circuit 4 is arranged as an H bridge or other arrangements. When the battery pack 3 is working, the battery cell 30 is connected in parallel to a DC motor. When used for a long time or a collision occurs, the independent battery cell 30 may be short-circuited with the parallel battery cell 30. The detection circuit 4 can detect each independent battery cell 30 or incorrect power-on when connecting the battery cell group 300 to ensure the safety of the battery cell group 300.

[0037] The shell 1 includes an upper shell 10, a lower shell 100, a main frame 11 and a side guard plate 12. An outer side of the upper shell 10 is provided with an embedded skirt 101, and the inner wall of the embedded skirt 101 is embedded with the outer wall of the lower shell 100. Both ends of the upper shell 10 and the lower shell 100 are provided with protrusions 102. The main frame 11 is arranged at the bottom of the battery pack 3 to fix its connection with the temperature control structure 2. The side guard plate 12 is arranged on the outer side of the battery pack 3 to fix its series structure. The embedded skirt 101 can completely wrap the outer circle of the lower shell 100, improve the sealing of the battery module, and avoid the intrusion of dust and water vapor. At the same time, both ends of the upper shell 10 and the lower shell 100 are provided with protrusions 102 that can be filled with other mechanical structures or buffers. When a collision occurs, the protrusion 102 can greatly absorb the collision kinetic energy and protect the safety of the battery cell 30.

[0038] The temperature control structure 2 includes a hydraulic control pipeline 21, a hydraulic control board 22, and a temperature assistant 23. The hydraulic control pipeline 21 is conductively connected with the hydraulic control board 22 and the temperature assistant 23. The hydraulic control board 22 contacts the surface of the battery cell group 300. A ceramic plate 24 is provided on the outer side of the hydraulic control board 22. A spherical capsule layer 20 is wrapped on the hydraulic control pipeline 21. The spherical capsule layer 20 includes a shell tube 200. The shell tube 200 is filled with phase change particles 2000. The phase change particles 2000 are encapsulated in a polyethylene sphere by a phase change material. Under low temperature conditions, the hydraulic control board 22 absorbs the cold air around the battery cell group 300 and transmits it to the liquid inside the hydraulic control pipeline 21. It flows to the liquid control plate 22, and the spherical capsule layer 20 outside the liquid control plate 22 exchanges heat with the liquid inside the liquid control pipeline 21, so that the phase change material inside the phase change particle 2000 solidifies to store the cold energy and prevents the battery from being affected by low temperature. When the temperature of the battery cell group 300 rises, the phase change material inside the phase change particle 2000 liquefies and conducts the cold energy to the liquid control plate 22 through the liquid control pipeline 21, thereby reducing the temperature of the battery cell group 300 and achieving the effect of shifting peaks and filling valleys. The advantage of this structure is that in non-extreme environments, the temperature control structure 2 can adjust the battery temperature by itself through external temperature changes, without the need for external power supply, thereby reducing battery life.

[0039] In extreme environments, the temperature assistant 23 can assist in heat release or cooling through the internal power supply of the battery cell group 300.

[0040] The shell tube 200 is in a hollow cylindrical or rectangular shape.

[0041] Carbon nanotubes or nano metal powder or nano wires are added to the phase change material to improve the heat storage and release efficiency of the phase change material.

[0042] The battery cell group 300 includes a battery cell shell 301 , a packaging layer 302 , and an insulating layer 303 . The battery cells 30 are arranged in parallel inside the battery cell shell 301 , the packaging layer 302 is arranged between the battery cell shell 301 and the battery cells 30 , and the insulating layer 303 is sandwiched between the packaging layer 302 and the battery cells 30 .

[0043] A series connection controller 304 is disposed outside the battery cell group 300 . The series connection controller 304 includes a detection connector 305 and a series connection board 306 . The detection connector 305 is connected to the detection circuit 4 . The series connection board 306 connects multiple battery cell groups 300 in series.

[0044] The detection circuit 4 includes four switches S1, S2, S3, S4 and continuous discharge diodes D1, D2, D3, D4. The continuous discharge diodes D1, D2, D3, D4 are connected in parallel with the corresponding switches S1, S2, S3, S4.

[0045] When switches S1, S4 are turned on and switches S2, S3 are turned off, the current flowing through the battery pack 312 increases. If switches S1, S2 are turned off and switches S3, S4 are turned on in the continuous discharge mode, the current flowing through the battery pack 3 decreases.

[0046] The current flows in the direction indicated by the arrow. M1, M2, and M3 represent measuring devices. SH1 and SH2 are measuring resistors. The current passes through the measuring devices M1 and M3 and the measuring resistors SH1 and SH2, and is measured by the measuring devices M1 and M3.

[0047] M1 and SH1 are connected in parallel between switch S3 (node ​​V1) and GND, M2 and SH1 and SH2 are connected in parallel between node V2 and GND. M3 and SH2 are connected in parallel between switch S3 (node ​​V3) and GND, SG1 and SG2 are short-circuit resistors connected to ground GND. SB1 and SB2 are short-circuit resistors connected to battery voltage Vbat.

[0048] The detection circuit 4 further comprises measuring devices M1, M2, M3, measuring resistors SH1, SH2 and resistors R1, R2, R3, wherein a first one of the resistors is associated with a positive reference voltage and a second one and a third one of the resistors have the same resistance value.

[0049] The detection circuit 4 further includes short-circuit resistors SG1 and SG2 , wherein the two short-circuit resistors SG1 and SG2 are grounded, and wherein the two short-circuit resistors SG1 and SG2 are connected to the battery voltage Vbat.

[0050] R1 represents a positive reference voltage, R2 and R3 have the same resistance value, and the resistance values ​​of the resistors R1, R2 and R3 are significantly higher than the resistance values ​​of the measuring resistors SH1 and SH2.

[0051] If there is no short circuit, the resistors SG1, SG2, SB1, and SB2 are high resistance. At this time, the currents flowing through SH1 and SH2 are in opposite directions and have different current magnitudes, but only different polarity signs.

[0052] The measuring device is used to measure whether there is a difference between the currents flowing through the measuring resistors SH1 and SH2 in the continuous discharge mode, and the resistance value of at least one of the short-circuit resistors SG1 and SG2 becomes smaller during the measurement.

[0053] The voltage at node V3 is positive, and the voltage at node V1 is negative. The voltage V3 can be measured by the measuring device M3. By determining the resistance values ​​of resistors R1, R2 and R3, which are significantly higher than the resistance value of the measuring resistor, a positive voltage can be set at V2, which is used to measure the current difference between SH1 and SH2. R1 refers to the positive reference voltage, and R2 and R3 have the same resistance value. During the continuous discharge mode, as long as the same current passes through SH1 and SH2, but the polarity signs are different, and the tolerance of the components is ignored, the voltage at V2 remains constant. The measuring device M2 is used to measure whether there is a difference between the currents flowing through SH1 and SH2 in the continuous discharge mode. When the resistance of resistors SG1, SG2, SB1, and SB2 becomes smaller, the incorrect power-on of the battery pack 3 is detected. The working state of the battery cell 30 of the battery pack 3 under abnormal temperature or collision can be accurately detected through the detection circuit 4, avoiding the overall failure caused by the short circuit of a single battery cell 30.

[0054] If a detection error occurs in the measuring device M3, it will be determined that the battery pack 3 is energized incorrectly. The above is only an embodiment of the present invention. The common sense such as the known specific structure and characteristics in the scheme is not described too much here. The ordinary technicians in the relevant field know all the common technical knowledge in the technical field of the invention before the application date or priority date, can know all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for the technicians in this field, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A low temperature resistant lithium battery module, characterized in that: The invention comprises a shell (1), a temperature control structure (2) and a battery pack (3), wherein the battery pack (3) and the temperature control structure (2) are installed inside the shell (1), the battery pack (3) is composed of a plurality of battery cell groups (300) connected in series and composed of battery cells (30) connected in parallel, a detection circuit (4) is provided at the connection point of each battery cell group (300), and the detection circuit (4) and the temperature control structure (2) are electrically connected to a computing terminal (40); The shell layer (1) comprises an upper shell (10), a lower shell (100), a main frame (11) and a side guard plate (12); the outer side of the upper shell (10) is provided with an engaging skirt (101); the inner wall of the engaging skirt (101) engages with the outer wall of the lower shell (100); both ends of the upper shell (10) and the lower shell (100) are provided with protrusions (102); the main frame (11) is arranged at the bottom of the battery pack (3) to fix the connection between the battery pack and the temperature control structure (2); and the side guard plate (12) is arranged at the outer side of the battery pack (3) to fix the series structure; The temperature control structure (2) comprises a hydraulic control pipeline (21), a hydraulic control plate (22), and a temperature assistant (23); the hydraulic control pipeline (21) is conductively connected to the hydraulic control plate (22) and the temperature assistant (23); the hydraulic control plate (22) is in contact with the surface of the battery pack (3); a ceramic plate (24) is provided on the outside of the hydraulic control plate (22); and a spherical capsule layer (20) is wrapped on the hydraulic control pipeline (21); The spherical capsule layer (20) comprises a shell tube (200), the shell tube (200) is filled with phase change particles (2000), and the phase change particles (2000) are encapsulated in a polyethylene sphere by a phase change material; carbon nanotubes or nano metal powder or nano wires are added to the phase change material; The battery cell group (300) comprises a battery cell shell layer (301), a packaging layer (302), and an insulating layer (303); the battery cells (30) are arranged in parallel with the inside of the battery cell shell layer (301); the packaging layer (302) is arranged between the battery cell shell layer (301) and the battery cells (30); and the insulating layer (303) is sandwiched between the packaging layer (302) and the battery cells (30); In a low temperature state, the liquid control plate (22) absorbs cold air around the battery cell group (300) and transmits it to the liquid inside the liquid control pipeline (21), which flows to the liquid control plate (22). The spherical capsule layer (20) outside the liquid control plate (22) exchanges heat with the liquid inside the liquid control pipeline (21), so that the phase change material inside the phase change particles (2000) solidifies to store cold energy, thereby preventing the battery from being affected by low temperature. When the temperature of the battery cell group (300) rises, the phase change material inside the phase change particles (2000) liquefies to conduct cold energy through the liquid control pipeline (21) to the liquid control plate (22), thereby reducing the temperature of the battery cell group (300). The detection circuit (4) comprises four switches and a diode, wherein the diode is connected in parallel with the corresponding switch; The detection circuit (4) further comprises a measuring device, a measuring resistor and a resistor, wherein a first resistor of the resistors is associated with a positive reference voltage, and a second resistor and a third resistor of the resistors have the same resistance value; The detection circuit (4) further comprises short-circuit resistors, wherein two of the short-circuit resistors are grounded, and two of the short-circuit resistors are connected to the battery voltage; The resistance value of the resistor is higher than the resistance value of the measuring resistor; The short-circuit resistor is high-resistance when not short-circuited, and the directions of the currents passing through the measuring resistors have different polarity signs.

2. A low temperature resistant lithium battery module according to claim 1, characterized in that: A series connection controller (304) is provided outside the battery cell group (300), the series connection controller (304) comprising a detection connector (305) and a series connection board (306), the detection connector (305) being connected to a detection circuit (4), and the series connection board (306) connecting a plurality of battery cell groups (300) in series.

Images