Composite sensing element, battery, battery management system and electronic equipment

Abstract

The invention relates to the technical field of temperature and magnetic field measurement, and discloses a composite sensing element, a battery, a battery management system and electronic equipment. The composite sensing element comprises a magnetoresistive element used for sensing magnetic field information around the magnetoresistive element based on a magnetoresistive anisotropy effect; and the temperature sensing element is electrically coupled with the magnetoresistive element and is used for sensing temperature information around the magnetoresistive element based on the characteristic that the resistivity of the magnetoresistive element monotonically changes along with the temperature. Through the synergistic effect of the magnetoresistive element and the temperature sensing element, the composite sensing element can synchronously realize magnetic field measurement and temperature measurement, has a relatively small volume, and simultaneously realizes the beneficial effects of simple structure and easy realization.

Description

Technical Field

[0001] This invention relates to the field of temperature and magnetic field measurement technology, and particularly to a composite sensing element, a battery, a battery management system, and an electronic device. Background Technology

[0002] With the vigorous development of new energy vehicles and energy storage technologies, battery safety monitoring has become particularly important.

[0003] Traditional battery management relies primarily on external temperature sensors and voltage / current detection, which cannot provide real-time information on the battery's internal state or predict potential hazards. Integrating both temperature and voltage / current sensors inside the battery would result in an excessively large battery size.

[0004] Composite sensors for temperature and magnetic field detection can be used for both temperature monitoring and magnetic field detection, and indirectly obtain current information.

[0005] In summary, researching a small composite sensor that can be used for both temperature and magnetic field monitoring is of great significance. Summary of the Invention

[0006] The purpose of this invention is to propose a composite sensing element, battery, battery management system, and electronic device to improve the problem of the large size of existing composite sensors that are compatible with temperature and magnetic field monitoring.

[0007] To achieve the above objectives, a first aspect of the present invention provides a composite sensing element, the composite sensing element comprising: A magnetoresistive element is used to sense magnetic field information around the magnetoresistive element based on the magnetoresistive anisotropy effect. A temperature sensing element, electrically coupled to the magnetoresistive element, is used to sense temperature information around the magnetoresistive element based on the characteristic that the resistivity of the magnetoresistive element changes with temperature.

[0008] According to some embodiments of the present invention, the magnetoresistive element includes a first Wheatstone bridge composed of a first bridge arm, a second bridge arm, a third bridge arm, and a fourth bridge arm coupled in sequence; the differential signal of the first Wheatstone bridge is related to the strength of the magnetic field around the magnetoresistive element; The temperature sensing element includes a first resistor, a second resistor, and a third resistor coupled in sequence; the magnetoresistive element is electrically coupled to the third resistor and the first resistor to form a second Wheatstone bridge. The differential signal of the second Wheatstone bridge is related to the temperature around the magnetoresistive element.

[0009] According to some embodiments of the present invention, the first resistor, the second resistor, and the third resistor are the same as the resistance of the magnetoresistive element when the ambient temperature is a first temperature and the ambient magnetic field is a first magnetic field; The first bridge arm, the second bridge arm, the third bridge arm, and the fourth bridge arm have the same resistance when the surrounding magnetic field is zero.

[0010] According to some embodiments of the present invention, the first bridge arm, the second bridge arm, the third bridge arm and the fourth bridge arm each include N magnetoresistive elements, wherein N is greater than 1, and the magnetoresistive elements have magnetoresistive anisotropy effects.

[0011] According to some embodiments of the present invention, the magnetic reluctance element is an AMR, and the ferromagnetic material in the AMR is permalloy.

[0012] According to some embodiments of the present invention, the composite sensing element further includes a flexible substrate layer and a transition metal layer. The flexible substrate layer is used to surround the magnetoresistive element and the temperature sensing element; The transition metal layer is used to separate the flexible substrate from the magnetoresistive element and the temperature sensing element.

[0013] According to some embodiments of the present invention, the flexible substrate layer is made of polyimide; The material of the transition metal layer is Ta; The thickness of the magnetoresistive element is less than 50 μm.

[0014] To achieve the above objectives, a second aspect of the present invention provides a battery comprising a battery stack and the aforementioned composite sensing element; The battery stack includes a positive electrode, a negative electrode, and a separator located between the positive electrode and the negative electrode; The composite sensing element is located between the positive electrode and the separator; The composite sensing element is used to collect magnetic field and temperature information inside the battery.

[0015] To achieve the above objectives, a third aspect of the present invention provides a battery management system, the battery management system including a signal processing module and the aforementioned battery; The signal processing module is electrically coupled to the composite sensing element in the battery, and is used to receive magnetic field and temperature information in the battery, and to perform safety monitoring based on the magnetic field and temperature information.

[0016] To achieve the above objectives, a fourth aspect of the present invention provides an electronic device comprising the aforementioned sensing element.

[0017] Therefore, compared with the prior art, the present invention has the following beneficial effects: The composite sensing element provided by this invention includes a magnetoresistive element for sensing magnetic field information around the magnetoresistive element based on the magnetoresistive anisotropy effect; and a temperature sensing element electrically coupled to the magnetoresistive element for sensing temperature information around the magnetoresistive element based on the characteristic of the magnetoresistive element's resistivity changing with temperature. This invention, through the synergistic effect of the magnetoresistive element and the temperature sensing element, enables the composite sensing element to simultaneously achieve magnetic field and temperature measurements while maintaining a small size, and also achieves the advantages of simple structure and ease of implementation. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a composite sensing element according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a first Wheatstone bridge according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the stacked state of a composite sensing element according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the stacked structure of a battery according to an embodiment of the present invention.

[0020] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0023] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0024] With the vigorous development of new energy vehicles and energy storage technologies, battery safety monitoring has become particularly important.

[0025] Traditional battery management relies primarily on external temperature sensors and voltage / current detection, which cannot provide real-time information on the battery's internal state or predict potential hazards. Integrating both temperature and voltage / current sensors inside the battery would result in an excessively large battery size.

[0026] Composite sensors for temperature and magnetic field detection can be used for both temperature monitoring and magnetic field detection, and indirectly obtain current information.

[0027] Therefore, it is of great significance to study a small composite sensor that can be used for both temperature and magnetic field monitoring.

[0028] This invention discloses a composite sensing unit to improve the large size of existing composite sensors that are compatible with temperature and magnetic field monitoring.

[0029] like Figure 1 As shown, the composite sensing element in this embodiment of the invention includes a magnetoresistive element 100 and a temperature sensing element 200.

[0030] The magnetoresistive element 100 is used to sense the magnetic field information around the magnetoresistive element based on the magnetoresistive anisotropy effect. The temperature sensing element 200 is electrically coupled to the magnetoresistive element 100 and is used to sense the temperature information around the magnetoresistive element 100 based on the characteristic that the resistivity of the magnetoresistive element 100 changes with temperature.

[0031] It should be understood that magnetoresistive elements exhibit magnetoresistive anisotropy, thus the differential signal of the first Wheatstone bridge structure composed of magnetoresistive elements can be used to feedback the resistance changes of each arm of the magnetoresistive element under a magnetic field. The resistivity of the magnetoresistive element can change with temperature, thus the second Wheatstone bridge composed of the magnetoresistive element and the temperature sensing element can be used to feedback the resistance changes of the magnetoresistive element at different temperatures. Furthermore, since the magnetoresistive element is shared by both Wheatstone bridges, the composite sensing element can achieve simultaneous monitoring of temperature and magnetic field while simultaneously miniaturizing the sensing element.

[0032] It should be understood that a magnetoresistive element with magnetoresistive anisotropy can output a first differential signal V related to the strength of the external magnetic field through a first Wheatstone bridge. 1out Therefore, this first differential signal can be used to represent the current magnetic field.

[0033] The magnetoresistive element and the temperature sensing element output a second temperature-related differential signal V through a second Wheatstone bridge. 2out The second differential signal V 2out Conforms to the formula: {V}_{2out}={V}_{cc}\left [ {\frac {1} {1+\frac {R(T)} {{R}_{1}}}-\frac {{R}_{2}} {{R}_{2}+{R}_{3}}} \right ] V cc The input voltage is given; the resistance values ​​of the magnetoresistive element and the three resistors coupled sequentially in the second Wheatstone bridge are R(T), R1, R2, and R3, respectively.

[0034] The resistance of the magnetoresistive element increases monotonically with temperature, and the second differential signal V 2out When the value of the second differential signal V increases synchronously with the increase of the resistance of the magnetoresistive element, the value of the second differential signal V... 2out The value of [value] increases monotonically with temperature. The resistance of the magnetoresistive element decreases monotonically with temperature, and the second differential signal V [value]... 2out When the value of the second differential signal V increases synchronously with the increase of the resistance of the magnetoresistive element, the value of the second differential signal V... 2out The value of this signal decreases monotonically with temperature. Therefore, this second differential signal can be used to represent the current temperature.

[0035] like Figure 1 As shown, the magnetoresistive element 100 in this embodiment of the invention includes a first Wheatstone bridge composed of a first bridge arm R41, a second bridge arm R42, a third bridge arm R43, and a fourth bridge arm R44 coupled in sequence; and the differential signal V of the first Wheatstone bridge 1out It is related to the strength of the magnetic field around the magnetoresistive element.

[0036] It should be understood that the first, second, third and / or fourth arms of the magnetoresistive element have magnetoresistive anisotropy, meaning that their resistance changes with the direction of the applied magnetic field relative to the direction of the current.

[0037] The temperature sensing element 200 of this embodiment includes a first resistor R1, a second resistor R2, and a third resistor R3 coupled in sequence; a magnetoresistive element 100 is electrically coupled to the third resistor R3 and the first resistor R1 to form a second Wheatstone bridge; and then the differential signal V of the second Wheatstone bridge... 2out It is related to the temperature around the magnetoresistive element.

[0038] It should be understood that the resistance values ​​of the first resistor R1, the second resistor R2, and the third resistor R3 are unaffected by temperature and magnetic field within a certain temperature range and a certain magnetic field range, i.e., they remain constant. Within a certain temperature range, the resistivity of the magnetoresistive element 100 can change linearly, monotonically, or monotonically with temperature variations.

[0039] To better achieve temperature measurement, the first resistor R1, the second resistor R2, and the third resistor R3 in this embodiment of the invention have the same resistance as the magnetoresistive element 100 when the ambient temperature is the first temperature and the ambient magnetic field is the first magnetic field.

[0040] It should be noted that the resistances of the first resistor R1, the second resistor R2, the third resistor R3, and the magnetoresistive element 100 can be the same or nearly the same when the ambient temperature and the ambient magnetic field are at the first temperature and the first magnetic field, and are not specifically limited here. The first temperature can be 25 degrees Celsius, or it can be adjusted according to the actual situation; the first magnetic field can be zero magnetic field, and is not specifically limited here.

[0041] The first bridge arm R11, the second bridge arm R12, the third bridge arm R13, and the fourth bridge arm R14 have the same resistance when the surrounding magnetic field is zero (0Oe).

[0042] Figure 2 This is a schematic diagram of the structure of the first Wheatstone bridge according to an embodiment of the present invention. Figure 2 As shown, in the first Wheatstone bridge, the first, second, third, and fourth arms are coupled sequentially. Each arm includes nine magnetic reluctance elements, which exhibit magnetoresistive anisotropy. The magnetic reluctance elements are strip-shaped, arranged in a serpentine pattern. The linewidth of each element is 30 μm, and the spacing between adjacent elements is 20 μm.

[0043] It should be noted that the number of magnetoresistive elements in each bridge arm is not limited to 9, but can be N, where N is greater than 1.

[0044] The magnetoresistive element in this embodiment of the invention is an AMR with magnetoresistive anisotropy. The AMR includes a ferromagnetic layer made of permalloy.

[0045] It should be understood that permalloy has high permeability, low coercivity, and moderate AMR effect, while its resistivity increases with temperature. This allows composite sensing elements with permalloy to be used for both magnetic field and temperature measurements.

[0046] It should be noted that cobalt is a ferromagnetic material with a resistivity temperature coefficient of 0.006 / ℃, meaning that the resistivity of cobalt increases by approximately 0.6% for every 1℃ increase; iron is a ferromagnetic material with a resistivity temperature coefficient of 0.00651 / ℃, meaning that the resistivity of iron increases by approximately 0.651% for every 1℃ increase. The material of the ferromagnetic layer in AMR is not limited to permalloy; it can also be Co, Fe, or other ferromagnetic materials, which are not specifically limited here.

[0047] The composite sensing element of this invention further includes a flexible substrate layer and a transition metal layer. The flexible substrate layer is used to surround the magnetoresistive element and the temperature sensing element to enhance the electrical insulation performance of the composite sensing element. The transition metal layer is used to separate the flexible substrate layer from the magnetoresistive element and the temperature sensing element to enhance the chemical stability of the composite sensing element.

[0048] Specifically, such as Figure 3 As shown, the composite sensing element of this embodiment includes a first flexible substrate layer 110, a first transition metal layer 120, a ferromagnetic layer 130, a resistive layer 210, a second transition metal layer 140, and a second flexible substrate layer 150. The first transition metal layer is located above the first flexible substrate layer, the ferromagnetic layer and the resistive layer are located above the first transition metal layer, the second transition metal layer is located above the ferromagnetic layer and the resistive layer, and the second flexible substrate layer is located above the second transition metal layer. The first and second flexible substrate layers are made of polyimide, the first and second transition metal layers are made of Ta, and the ferromagnetic layer is made of permalloy. The ferromagnetic layer comprises magnetoresistive elements with magnetoresistive anisotropy. The resistive layer comprises a first resistor, a second resistor, and a third resistor with fixed resistance values ​​in a temperature sensing element.

[0049] It should be understood that both the ferromagnetic layer and the resistive layer are surrounded by a transition metal layer and a flexible substrate layer, providing multi-layer protection for the composite sensing element. Composite sensing elements with flexible substrates can be bent, folded, and stretched as needed, expanding the application range of composite sensing elements.

[0050] The present invention also discloses a battery, which includes a battery stack and the aforementioned composite sensing element.

[0051] like Figure 4As shown, the battery stack includes a positive electrode, a negative electrode, and a separator located between the positive and negative electrodes. A composite sensing element is located between the positive electrode and the separator. This composite sensing element is used to acquire temperature and magnetic field information of the battery.

[0052] It should be noted that the composite sensing element can also be located between the negative electrode and the diaphragm; this is not specifically limited here.

[0053] This invention also discloses a battery management system, which includes a signal processing module and the aforementioned battery.

[0054] In this embodiment of the invention, the signal processing module is electrically coupled to the composite sensing element inside the battery. The signal processing module is used to receive magnetic field and temperature information inside the battery and to perform safety monitoring based on the magnetic field and temperature information.

[0055] Specifically, the signal processing module is used to receive the magnetic field signal output by the composite sensing element and determine the current magnetic field information based on the magnetic field signal, determine the current current information based on the current magnetic field information, determine whether there is a first risk such as overcharging or over-discharging based on the current current information, and automatically send an alarm or reminder or trigger action command when there is a first risk.

[0056] The signal processing module is also used to receive the temperature electrical signal output by the composite sensing element and determine the current temperature information based on the temperature electrical signal, determine whether there is a second risk such as overheating based on the current temperature information, and automatically send alarm, reminder or trigger action command when there is a second risk.

[0057] The signal processing module is also used to determine the presence of a third risk based on the current magnetic field and temperature information, and automatically send alarms, reminders, or trigger action commands when a third risk exists. It uses the electrical signal output by the information composite sensing element to determine the current magnetic field and temperature information, and to determine whether the third risk exists based on the current magnetic field and temperature information.

[0058] The present invention also discloses an electronic device, which includes the aforementioned composite sensing element.

[0059] Therefore, compared with the prior art, the present invention has the following beneficial effects: The composite sensing element provided by this invention includes a magnetoresistive element for sensing magnetic field information around the magnetoresistive element based on the magnetoresistive anisotropy effect; and a temperature sensing element electrically coupled to the magnetoresistive element for sensing temperature information around the magnetoresistive element based on the characteristic of the magnetoresistive element's resistivity changing with temperature. This invention, through the synergistic effect of the magnetoresistive element and the temperature sensing element, enables the composite sensing element to simultaneously achieve magnetic field and temperature measurements while maintaining a small size, and also achieves the advantages of simple structure and ease of implementation.

[0060] The above are merely exemplary embodiments of the present invention and do not limit the scope of the patent of the present invention. All equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. A composite sensing element, characterized in that, include: A magnetoresistive element is used to sense magnetic field information around the magnetoresistive element based on the magnetoresistive anisotropy effect. A temperature sensing element, electrically coupled to the magnetoresistive element, is used to sense temperature information around the magnetoresistive element based on the characteristic that the resistivity of the magnetoresistive element changes monotonically with temperature.

2. The composite sensing element according to claim 1, characterized in that, The magnetoresistive element includes a first Wheatstone bridge composed of a first bridge arm, a second bridge arm, a third bridge arm, and a fourth bridge arm coupled in sequence; the differential signal of the first Wheatstone bridge is related to the strength of the magnetic field around the magnetoresistive element. The temperature sensing element includes a first resistor, a second resistor, and a third resistor coupled in sequence; the magnetoresistive element is electrically coupled to the third resistor and the first resistor to form a second Wheatstone bridge. The differential signal of the second Wheatstone bridge is related to the temperature around the magnetoresistive element.

3. The composite sensing element according to claim 2, characterized in that, The first resistor, the second resistor, and the third resistor have the same resistance as the magnetoresistive element when the ambient temperature is a first temperature and the ambient magnetic field is a first magnetic field. The first bridge arm, the second bridge arm, the third bridge arm, and the fourth bridge arm have the same resistance when the surrounding magnetic field is zero.

4. The composite sensing element according to claim 3, characterized in that, The first bridge arm, the second bridge arm, the third bridge arm and the fourth bridge arm each include N magnetoresistive elements, where N is greater than 1, and the magnetoresistive elements have magnetoresistive anisotropy effect.

5. The composite sensing element according to claim 4, characterized in that, The magnetoresistive element is an AMR, and the ferromagnetic layer in the AMR is made of permalloy.

6. The composite sensing element according to claim 2, characterized in that, The composite sensing element also includes a flexible substrate layer and a transition metal layer. The flexible substrate layer is used to surround the magnetoresistive element and the temperature sensing element; The transition metal layer is used to separate the flexible substrate from the magnetoresistive element and the temperature sensing element.

7. The composite sensing element according to claim 6, characterized in that, The flexible substrate layer is made of polyimide; The material of the transition metal layer is Ta; The thickness of the magnetoresistive element is less than 50 μm.

8. A battery, characterized in that, The battery includes a battery stack and a composite sensing element as described in any one of claims 1-7; The battery stack includes a positive electrode, a separator, and a negative electrode stacked in sequence; The composite sensing element is used to collect magnetic field and temperature information inside the battery.

9. A battery management system, characterized in that, Includes a signal processing module and the battery as described in claim 8; The signal processing module is electrically coupled to the composite sensing element in the battery, and is used to receive magnetic field and temperature information in the battery, and to perform safety monitoring based on the magnetic field and temperature information.

10. An electronic device, characterized in that, Includes the sensing element according to any one of claims 1-7.

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