Battery device

Abstract

The utility model relates to battery equipment, a positive pole lug of a battery cell is connected with a positive pole column, a negative pole lug of the battery cell is connected with a negative pole column, the positive pole column and the negative pole column are used for being connected with an external load, and a charging and discharging loop is formed by the positive pole column, the external load, the negative pole column, the negative pole lug and the positive pole lug. And charging and discharging operations between the battery cell and the external load can be realized. The at least two positive temperature coefficient thermistors are connected in series in the charging and discharging loop formed by the positive pole, the external load, the negative pole, the negative tab and the positive tab, so that the resistance of the positive temperature coefficient thermistors is relatively small in a conventional state, and charging and discharging are not influenced. When the battery equipment is subjected to abnormal charging and discharging behaviors such as external positive and negative electrode short circuit, overcharging and over-discharging, the charging and discharging loop generates large current, the temperature of the loop is increased, the resistance value of the positive temperature coefficient thermistor is correspondingly increased, the current of the charging and discharging loop is further reduced, and the safety performance of the battery is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery device. Background Art

[0002] With the development of new energy technologies, secondary batteries represented by lithium batteries have gradually been applied to energy storage power systems, electric vehicles, military equipment, aerospace and other fields, bringing great convenience to people's daily production and life.

[0003] During operation, lithium batteries are prone to abnormal charging and discharging behaviors such as external positive and negative short circuits, overcharging, and over-discharging, which can cause the current in the battery charging and discharging circuit to increase, seriously affecting battery safety. Utility Model Content

[0004] Based on this, it is necessary to propose a battery device to alleviate the phenomenon of increased current in the battery charging and discharging circuit due to abnormal charging and discharging behavior and improve the battery safety performance.

[0005] The present application provides a battery device, including a battery cell, a positive electrode post, a negative electrode post and at least two positive temperature coefficient thermistors, wherein the battery cell includes a positive electrode tab and a negative electrode tab; the positive electrode post is connected to the positive electrode tab, and the positive electrode post is used to connect to an external load; the negative electrode post is connected to the negative electrode tab, and the negative electrode post is used to connect to an external load; the positive temperature coefficient thermistor is connected in series in a charge and discharge circuit formed by the positive electrode post, the external load, the negative electrode post, the negative electrode tab and the positive electrode tab.

[0006] In the above scheme, the positive electrode tab of the battery cell is connected to the positive electrode post, the negative electrode tab of the battery cell is connected to the negative electrode post, and the positive electrode post and the negative electrode post are used to connect to the external load. In this way, a charge and discharge circuit is formed by the positive electrode post, the external load, the negative electrode post, the negative electrode tab and the positive electrode tab, and the charging and discharging operations between the battery cell and the external load can be realized. By connecting at least two positive temperature coefficient thermistors in series in the charge and discharge circuit formed by the positive electrode post, the external load, the negative electrode post, the negative electrode tab and the positive electrode tab, under normal conditions, the resistance of the positive temperature coefficient thermistor is small and will not affect the charge and discharge. However, in the battery equipment, due to abnormal charge and discharge behaviors such as external positive and negative short circuits, overcharging, and over-discharging, the charge and discharge circuit generates a large current. After the circuit temperature is increased, the resistance of the positive temperature coefficient thermistor will increase accordingly, thereby reducing the current of the charge and discharge circuit and improving the battery safety performance.

[0007] In some embodiments, the number of the battery cells is multiple, the positive electrode tabs of each of the battery cells are connected, and the total positive electrode formed is connected to the positive electrode column, the negative electrode tabs of each of the battery cells are connected, and the total negative electrode formed is connected to the negative electrode column, and the positive temperature coefficient thermistor is connected in series in a charging and discharging circuit formed by the total positive electrode, the positive electrode column, the external load, the negative electrode column and the total negative electrode.

[0008] In the above scheme, the positive electrode tabs of multiple battery cells are connected to form a total positive electrode, and the negative electrode tabs of multiple battery cells are connected to form a total negative electrode. A positive temperature coefficient thermistor is connected in series in the charge and discharge circuit formed by the total positive electrode-positive electrode column-external load-negative electrode column-total negative electrode. There is no need to configure a positive temperature coefficient thermistor for each battery cell, so that all battery cells can be protected, thereby alleviating the phenomenon of increased battery volume due to the configuration of the positive temperature coefficient thermistor.

[0009] In some embodiments, the positive temperature coefficient thermistor includes a first positive temperature coefficient thermistor and a second positive temperature coefficient thermistor, the total positive electrode is connected to the positive electrode column through the first positive temperature coefficient thermistor, and the total negative electrode is connected to the negative electrode column through the second positive temperature coefficient thermistor.

[0010] The above scheme adopts two positive temperature coefficient thermistors, which are respectively connected in series between the total positive electrode and the positive electrode column and between the total negative electrode and the negative electrode column. When any battery cell heats up due to excessive loop current, the positive temperature coefficient thermistor can be used to reduce the loop current, thereby protecting the battery cell, with lower hardware cost.

[0011] In some embodiments, the positive temperature coefficient thermistor includes a first positive temperature coefficient thermistor and a second positive temperature coefficient thermistor, the first positive temperature coefficient thermistor is embedded in the positive electrode column, and the second positive temperature coefficient thermistor is embedded in the negative electrode column.

[0012] The above solution embeds two positive temperature coefficient thermistors into the positive electrode column and the negative electrode column respectively, which can improve the battery space utilization and the battery energy density to a certain extent.

[0013] In some embodiments, the number of the battery cells is multiple, the positive electrode tabs of each of the battery cells are connected, and the total positive electrode formed is connected to the positive electrode column, the negative electrode tabs of each of the battery cells are connected, and the total negative electrode formed is connected to the negative electrode column, the positive temperature coefficient thermistor is arranged between the positive electrode tab of at least one of the battery cells and the total positive electrode, and the positive temperature coefficient thermistor is arranged between the negative electrode tab of at least one of the battery cells and the total negative electrode.

[0014] In the above scheme, the positive temperature coefficient thermistor is simultaneously connected in series between the positive electrode tab of at least one battery cell and the total positive electrode, and between the negative electrode tab of at least one battery cell and the total negative electrode, thereby limiting the increase of the loop current from the positive electrode and the negative electrode respectively, thereby improving the operating safety of a single battery cell.

[0015] In some embodiments, there are multiple battery cells, the positive electrode tabs of each battery cell are connected, and the total positive electrode formed is connected to the positive electrode column, the negative electrode tabs of each battery cell are connected, and the total negative electrode formed is connected to the negative electrode column, and the positive temperature coefficient thermistor is respectively arranged between the positive electrode tabs of at least two of the battery cells and the total positive electrode.

[0016] In the above scheme, multiple positive temperature coefficient thermistors are connected in series between the positive electrode tabs of each battery cell and the total positive electrode, so as to protect a single battery cell from the positive electrode and reduce the influence of the configuration of the positive temperature coefficient thermistor on the volume of a single battery cell.

[0017] In some embodiments, there are multiple battery cells, the positive electrode tabs of each battery cell are connected, and the total positive electrode formed is connected to the positive electrode column, the negative electrode tabs of each battery cell are connected, and the total negative electrode formed is connected to the negative electrode column, and the positive temperature coefficient thermistor is respectively arranged between the negative electrode tabs of at least two of the battery cells and the total negative electrode.

[0018] In the above scheme, multiple positive temperature coefficient thermistors are connected in series between the negative electrode tabs of each battery cell and the total negative electrode, respectively, to protect a single battery cell from the negative electrode, thereby reducing the impact of the configuration of the positive temperature coefficient thermistor on the volume of a single battery cell.

[0019] In some embodiments, the positive temperature coefficient thermistor is a positive temperature coefficient thermistor having a transition temperature of 80° C.-300° C.

[0020] The above scheme uses a positive temperature coefficient thermistor with a transition temperature of 80°C-300°C to limit the loop current of the battery equipment. The loop current can be limited while maintaining the normal operation of the battery cell, thereby improving the operating reliability of the battery equipment.

[0021] In some embodiments, the positive temperature coefficient thermistor is a positive temperature coefficient thermistor having a transition temperature of 80° C.-200° C.

[0022] The above scheme further uses a positive temperature coefficient thermistor with a transition temperature of 80°C-200°C to limit the loop current of the battery device, further improving the battery operation reliability and safety.

[0023] In some embodiments, the positive temperature coefficient thermistor is a positive temperature coefficient thermistor of the type having a resistance value less than or equal to 2 mΩ before reaching the transition temperature.

[0024] The above scheme uses a positive temperature coefficient thermistor with a resistance value less than or equal to 2mΩ when the transition temperature is not reached to limit the loop current of the battery device, thereby reducing the influence of the thermistor on the charge and discharge current of the battery device under normal operating conditions.

[0025] In some embodiments, the positive temperature coefficient thermistor is a type of positive temperature coefficient thermistor having a resistance value less than or equal to 1 mΩ before reaching the transition temperature.

[0026] The above scheme further uses a positive temperature coefficient thermistor with a resistance value less than or equal to 1mΩ when the transition temperature is not reached to limit the loop current of the battery device, which can further reduce the impact of the thermistor on the charge and discharge current under normal operating conditions and improve the operating reliability of the battery device. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0028] Figure 1 This is a schematic diagram of the battery device structure in some embodiments of the present application;

[0029] Figure 2 This is a schematic diagram of the structure of a battery device in some other embodiments of the present application;

[0030] Figure 3 This is a schematic diagram of the structure of a battery device in some other embodiments of the present application;

[0031] Figure 4 This is a schematic diagram of the battery device structure in some further embodiments of the present application.

[0032] Description of reference numerals:

[0033] 10-battery cell, 20-positive electrode column, 30-negative electrode column, 40-positive temperature coefficient thermistor, 11-positive electrode ear, 12-negative electrode ear; 21-total positive electrode, 22-total negative electrode, 41-first positive temperature coefficient thermistor, 42-second positive temperature coefficient thermistor. DETAILED DESCRIPTION

[0034] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0036] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0037] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0038] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0039] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0040] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0041] At present, judging from the development of the market situation, the application of batteries is becoming more and more extensive. They are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of battery application fields, the market demand is also constantly expanding.

[0042] Battery safety is an important means to maintain the safe operation of energy storage power systems, electric vehicles, military equipment, etc. However, the current batteries are prone to overheating during use, and as the battery temperature rises, it may even cause the battery to explode.

[0043] Through in-depth research, it was found that the above phenomenon is generally caused by abnormal charging and discharging behaviors such as short circuit of the positive and negative poles outside the battery cell, overcharging, and over-discharging. When the external positive and negative poles of the battery cell are short-circuited, if the external short resistance is small (for example, less than the first resistance threshold), the loop current of the battery cell will be particularly large, and the internal adapter will form a weak area, acting as a fuse and directly melting, thereby improving the safety of the battery cell. When the external short resistance is large (for example, greater than the second resistance threshold, where the second resistance threshold is greater than the first resistance threshold), the loop current of the battery cell will be relatively small, which is not enough to cause abnormal temperature rise of the battery cell, and the battery cell can still operate normally. However, when the external short resistance is between the first resistance threshold and the second resistance threshold, the loop current is not enough to cause the internal adapter to melt, but it will cause abnormal temperature rise of the battery cell, eventually leading to excessive temperature of the battery cell, which may cause smoke when the valve opens, and may cause explosion in severe cases.

[0044] In order to alleviate the above phenomenon, it is possible to consider connecting a load in series with the charging and discharging circuit of the battery cell. When the battery cell temperature is low, this load will not affect the normal charging and discharging of the battery cell. When the battery cell heats up due to abnormal use, the current in the charging and discharging circuit can be suppressed or reduced, thereby alleviating the temperature rise of the battery cell and allowing the battery cell to operate normally.

[0045] Based on the above considerations, the positive electrode tab of the battery cell can be connected to the positive electrode post, the negative electrode tab of the battery cell can be connected to the negative electrode post, and the positive electrode post and the negative electrode post are used to connect to the external load. In this way, a charging and discharging circuit is formed by the positive electrode post, the external load, the negative electrode post, the negative electrode tab and the positive electrode tab, and the charging and discharging operations between the battery cell and the external load can be realized.

[0046] By connecting at least two positive temperature coefficient thermistors in series in the charge and discharge circuit formed by the positive pole, external load, negative pole, negative pole tab and positive pole tab, under normal conditions, the resistance of the positive temperature coefficient thermistor is small and will not affect the charge and discharge. However, due to abnormal charge and discharge behaviors such as external positive and negative pole short circuit, overcharge, over discharge, etc., the charge and discharge circuit of the battery equipment generates a large current. After the circuit temperature is increased, the resistance of the positive temperature coefficient thermistor will increase accordingly, thereby reducing the current of the charge and discharge circuit and improving the safety performance of the battery.

[0047] The temperature monitoring circuit provided in the embodiment of the present application is applied to a battery device, and the battery device includes at least one battery cell. When there are multiple battery cells, the multiple battery cells can be connected in series and / or in parallel. The battery device can be a power battery that provides power for electric vehicles, etc., or an energy storage battery used in energy storage systems and other scenarios, without specific limitation.

[0048] See also Figure 1 The present application provides a battery device, including a battery cell 10, a positive electrode column 20, a negative electrode column 30 and at least two positive temperature coefficient thermistors 40, the battery cell 10 includes a positive electrode tab 11 and a negative electrode tab 12; the positive electrode column 20 is connected to the positive electrode tab 11, and the positive electrode column 20 is used to connect to an external load; the negative electrode column 30 is connected to the negative electrode tab 12, and the negative electrode column 30 is used to connect to an external load; the positive temperature coefficient thermistor 40 is connected in series in a charge and discharge circuit formed by the positive electrode column 20, the external load, the negative electrode column 30, the negative electrode tab 12 and the positive electrode tab 11.

[0049] Specifically, the positive electrode tab 11 is a metal conductor used to draw out the positive current of the battery cell 10 in the battery device. Its main function is to connect the positive active material inside the battery cell 10 with the external circuit to achieve the output of electric energy. The negative electrode tab 12 is a metal conductor used to draw out the negative current of the battery cell 10 in the battery device. Its main function is to connect the negative active material inside the battery cell 10 with the external circuit to complete the current loop. In lithium-ion batteries, the positive electrode tab 11 and the negative electrode tab 12 are usually made of conductive metal materials. For example, in some embodiments, the positive electrode tab 11 can be made of aluminum material, which has good conductivity and corrosion resistance, and the negative electrode tab 12 can be made of pure nickel strip or nickel-plated copper strip.

[0050] The positive pole 20 is an interface of the battery device. It is connected to the external circuit as the positive pole of the battery device and is used to transmit the electric energy of the battery device to the external circuit. It usually uses metals such as lead, zinc, copper, and cadmium as conductive materials. The negative pole 30 is another interface of the battery device. It is connected to the external circuit as the negative pole of the battery device to complete the current loop. It is usually made of metal materials with good conductive properties. The positive temperature coefficient thermistor 40 (Positive Temperature Coefficient, PTC) is a temperature-sensitive semiconductor resistor whose resistance value increases with the increase of temperature.

[0051] In actual scenarios, after the positive pole 20 and the negative pole 30 are connected to an external load, the current of the battery cell 10 can be transmitted to the external load through the positive pole tab 11 and the positive pole 20 in sequence, and then return to the battery cell 10 through the external load, the negative pole 30 and the negative pole tab 12 in sequence, forming a complete charge and discharge circuit, and at least two (including two) positive temperature coefficient thermistors 40 are connected in series to this charge and discharge circuit. In this way, when the battery cell 10 has an external short circuit and the circuit current increases, and the temperature of the battery cell 10 rises, the positive temperature coefficient thermistor 40 increases due to the increase in temperature, which reduces the current of the charge and discharge circuit, thereby suppressing the temperature rise of the battery cell 10, so that the battery cell 10 can continue to operate normally.

[0052] It should be pointed out that in actual scenarios, a connecting component such as an adapter may be configured between the positive electrode tab 11 and the positive electrode column 20, which will not be elaborated here. It is only necessary to connect the positive temperature coefficient thermistor 40 in series in the charging and discharging circuit of the battery equipment to reduce the circuit current by increasing the resistance.

[0053] In the above scheme, the positive electrode tab 11 of the battery cell 10 is connected to the positive electrode post 20, the negative electrode tab 12 of the battery cell 10 is connected to the negative electrode post 30, and the positive electrode post 20 and the negative electrode post 30 are used to connect to the external load. In this way, a charge and discharge circuit is formed by the positive electrode post 20, the external load, the negative electrode post 30, the negative electrode tab 12 and the positive electrode tab 11, and the charging and discharging operations between the battery cell 10 and the external load can be realized. By connecting at least two positive temperature coefficient thermistors 40 in series in the charge and discharge circuit formed by the positive electrode post 20, the external load, the negative electrode post 30, the negative electrode tab 12 and the positive electrode tab 11, under normal conditions, the resistance of the positive temperature coefficient thermistor 40 is small and will not affect the charging and discharging. However, due to abnormal charging and discharging behaviors such as external positive and negative short circuits, overcharging, and over-discharging in the battery device, a large current is generated in the charging and discharging circuit. After the circuit temperature is increased, the resistance of the positive temperature coefficient thermistor 40 will increase accordingly, thereby reducing the current in the charging and discharging circuit and improving the battery safety performance.

[0054] Furthermore, in the technical solution of the present application, by setting at least two positive temperature coefficient thermistors 40, when any one of the positive temperature coefficient thermistors 40 fails, the battery equipment protection can also be achieved through another positive temperature coefficient thermistor 40. When any one of the positive temperature coefficient thermistors 40 detects that the temperature of the battery cell 10 is too high, it can trigger an increase in resistance to reduce the loop current. When multiple positive temperature coefficient thermistors 40 simultaneously detect that the temperature of the battery cell 10 is too high, they can simultaneously trigger an increase in resistance, which can reduce the loop current more quickly. In this way, the operating reliability of the battery equipment can be further improved.

[0055] See also Figure 2 In some embodiments, there are multiple battery cells 10, the positive electrode tabs 11 of each battery cell 10 are connected, and the total positive electrode 21 formed is connected to the positive electrode column 20, the negative electrode tabs 12 of each battery cell 10 are connected, and the total negative electrode 22 formed is connected to the negative electrode column 30, and the positive temperature coefficient thermistor 40 is connected in series in the charging and discharging circuit formed by the total positive electrode 21, the positive electrode column 20, the external load, the negative electrode column 30 and the total negative electrode 22.

[0056] Specifically, in actual scenarios, the number of battery cells 10 is often not unique, and the positive pole tabs 11 of each battery cell 10 are connected to each other, and the common connection point of the positive pole tabs 11 of each battery cell 10 is used as the total positive pole 21; the negative pole tabs 12 of each battery cell 10 are connected to each other, and the common connection point of the negative pole tabs 12 of each battery cell 10 is used as the total negative pole 22. In this way, the electric energy of multiple battery cells 10 can be transmitted to the electrode pole through the total positive pole 21, and flow back to each battery cell 10 through the total negative pole 22, so that multiple battery cells 10 can supply power to external loads.

[0057] In the solution of this embodiment, the positive temperature coefficient thermistor 40 is connected in series in the charge and discharge circuit formed by the total positive electrode 21, the positive electrode column 20, the external load, the negative electrode column 30 and the total negative electrode 22. That is, the positive temperature coefficient thermistor 40 can be connected in series between the total positive electrode 21 and the external load, or between the total negative electrode 22 and the external load. In this way, multiple battery cells 10 share the positive temperature coefficient thermistor 40.

[0058] In the above scheme, the positive electrode tabs 11 of multiple battery cells 10 are connected to form a total positive electrode 21, and the negative electrode tabs 12 of multiple battery cells 10 are connected to form a total negative electrode 22. A positive temperature coefficient thermistor 40 is connected in series in the charge and discharge circuit formed by the total positive electrode 21-positive electrode column 20-external load-negative electrode column 30-total negative electrode 22. There is no need to configure a positive temperature coefficient thermistor 40 for each battery cell 10, so that all battery cells 10 can be protected, thereby alleviating the phenomenon of increased battery volume due to the configuration of the positive temperature coefficient thermistor 40.

[0059] Please continue reading Figure 2 In some embodiments, the positive temperature coefficient thermistor 40 includes a first positive temperature coefficient thermistor 41 and a second positive temperature coefficient thermistor 42, the total positive electrode 21 is connected to the positive electrode column 20 through the first positive temperature coefficient thermistor 41, and the total negative electrode 22 is connected to the negative electrode column 30 through the second positive temperature coefficient thermistor 42.

[0060] Specifically, the positive temperature coefficient thermistor 40 is connected in series between the total positive electrode 21 and the external load, and specifically can be any position of the connection line between the total positive electrode 21 and the external load. The positive temperature coefficient thermistor 40 is connected in series between the total negative electrode 22 and the external load, and specifically can be any position of the connection line between the total negative electrode 22 and the external load. The solution of this embodiment is specifically explained by taking two positive temperature coefficient thermistors 40 as an example, one of which is connected in series between the total positive electrode 21 and the positive electrode pole 20, and the other is connected in series between the total negative electrode 22 and the negative electrode pole 30, so as to reduce the influence of the positive temperature coefficient thermistor 40 on the charging and discharging operation.

[0061] The above scheme adopts two positive temperature coefficient thermistors 40, which are respectively connected in series between the total positive electrode 21 and the positive electrode column 20 and between the total negative electrode 22 and the negative electrode column 30. When any battery cell 10 heats up due to excessive loop current, the positive temperature coefficient thermistor 40 can reduce the loop current and thus protect the battery cell 10, with lower hardware cost.

[0062] See also Figure 3 In some embodiments, the positive temperature coefficient thermistor 40 includes a first positive temperature coefficient thermistor 41 and a second positive temperature coefficient thermistor 42 , the first positive temperature coefficient thermistor 41 is embedded in the positive electrode 20 , and the second positive temperature coefficient thermistor 42 is embedded in the negative electrode 30 .

[0063] Specifically, this embodiment also uses two positive temperature coefficient thermistors 40 as an example for explanation. In the solution of this embodiment, the two positive temperature coefficient thermistors 40 are respectively embedded in the positive electrode column 20 and the negative electrode column 30, and the effect of being connected in series to the charge and discharge circuit can also be achieved. In addition, through this setting method, there is no need to reserve a position for the positive temperature coefficient thermistor 40 in the battery device. It is only necessary to improve the structure of the original positive electrode column 20 and the negative electrode column 30 and open a setting space for the positive temperature coefficient thermistor 40 therein.

[0064] In the above solution, two positive temperature coefficient thermistors 40 are respectively embedded in the positive electrode column 20 and the negative electrode column 30, which can improve the battery space utilization rate and the battery energy density to a certain extent.

[0065] Furthermore, in some embodiments, the positive temperature coefficient thermistor 40 can be connected between the total electrode (i.e., the total positive electrode 21 or the total negative electrode 22) and the pole (i.e., the positive pole 20 or the negative pole 30) in an additional configuration setting position, and embedded in the interior of the pole in an embedded form.

[0066] For example, the number of positive temperature coefficient thermistors 40 is two, one of which is embedded in the positive electrode column 20 or the negative electrode column 30, and the other is connected in series between the positive electrode column 20 and the total positive electrode 21, or connected in series between the negative electrode column 30 and the total negative electrode 22. In another embodiment, the number of positive temperature coefficient thermistors 40 is four, the first one is embedded in the positive electrode column 20, the second one is embedded in the negative electrode column 30, the third one is connected in series between the positive electrode column 20 and the total positive electrode 21, and the fourth one is connected in series between the negative electrode column 30 and the total negative electrode 22.

[0067] See also Figure 4 In some embodiments, there are multiple battery cells 10, the positive electrode tabs 11 of each battery cell 10 are connected to form a total positive electrode 21 connected to the positive electrode column 20, the negative electrode tabs 12 of each battery cell 10 are connected to form a total negative electrode 22 connected to the negative electrode column 30, a positive temperature coefficient thermistor 40 is arranged between the positive electrode tab 11 of at least one battery cell 10 and the total positive electrode 21, and a positive temperature coefficient thermistor 40 is arranged between the negative electrode tab 12 of at least one battery cell 10 and the total negative electrode 22.

[0068] Specifically, when there are multiple cells 10 in the battery device, all cells 10 may be respectively configured with a positive temperature coefficient thermistor 40, or only some cells 10 may be configured with a positive temperature coefficient thermistor 40. When all cells 10 are respectively configured with a positive temperature coefficient thermistor 40, each cell 10 may be configured with only one positive temperature coefficient thermistor 40 (connected in series between the negative electrode tab 12 and the total negative electrode 22, or connected in series between the positive electrode tab 11 and the total positive electrode 21), or at least one cell 10 may be configured with two positive temperature coefficient thermistors 40 (connected in series between the negative electrode tab 12 and the total negative electrode 22, and between the positive electrode tab 11 and the total positive electrode 21). When only some cells 10 are configured with a positive temperature coefficient thermistor 40, these (more than two) cells 10 may be respectively configured with one positive temperature coefficient thermistor 40, or these cells 10 may be configured with two positive temperature coefficient thermistors 40, and there is no specific limitation.

[0069] For example, in one embodiment, a positive temperature coefficient thermistor 40 may be connected in series between the positive electrode tab 11 of each battery cell 10 and the total positive electrode 21, and a positive temperature coefficient thermistor 40 may also be connected in series between the negative electrode tab 12 of each battery cell 10 and the total negative electrode 22. In another embodiment, a positive temperature coefficient thermistor 40 may be connected in series between the positive electrode tab 11 of a portion of the battery cells 10 and the total positive electrode 21, and a positive temperature coefficient thermistor 40 may be connected in series between the negative electrode tab 12 of another portion of the battery cells 10 and the total negative electrode 22.

[0070] In the above scheme, the positive temperature coefficient thermistor 40 is simultaneously connected in series between the positive electrode tab 11 of at least one battery cell 10 and the total positive electrode 21, and between the negative electrode tab 12 of at least one battery cell 10 and the total negative electrode 22, thereby limiting the increase of the loop current from the positive electrode and the negative electrode respectively, thereby improving the operating safety of a single battery cell 10.

[0071] In some embodiments, there are multiple battery cells 10, the positive electrode tabs 11 of each battery cell 10 are connected, and the total positive electrode 21 formed is connected to the positive electrode column 20, the negative electrode tabs 12 of each battery cell 10 are connected, and the total negative electrode 22 formed is connected to the negative electrode column 30, and a positive temperature coefficient thermistor 40 is respectively arranged between the positive electrode tabs 11 of at least two battery cells 10 and the total positive electrode 21.

[0072] Specifically, in the solution of this embodiment, the positive temperature coefficient thermistor 40 is configured at the positive electrode of the battery device, and the positive temperature coefficient thermistor 40 is independently configured for each battery cell 10. In more detail, in one embodiment, a positive temperature coefficient thermistor 40 may be connected in series between the positive electrode tab 11 of each battery cell 10 and the total positive electrode 21, and a positive temperature coefficient thermistor 40 may be partially or completely connected in series between the negative electrode tab 12 and the total negative electrode 22, or no positive temperature coefficient thermistor 40 may be connected in series between the positive electrode tab 11 and the total positive electrode 21.

[0073] In the above scheme, multiple positive temperature coefficient thermistors 40 are respectively connected in series between the positive electrode tabs 11 of each battery cell 10 and the total positive electrode 21, so as to protect the single battery cell 10 from the positive electrode and reduce the influence of the configuration of the positive temperature coefficient thermistor 40 on the volume of the single battery cell 10.

[0074] In some embodiments, there are multiple battery cells 10, the positive electrode tabs 11 of each battery cell 10 are connected, and the total positive electrode 21 formed is connected to the positive electrode column 20, the negative electrode tabs 12 of each battery cell 10 are connected, and the total negative electrode 22 formed is connected to the negative electrode column 30, and a positive temperature coefficient thermistor 40 is respectively arranged between the negative electrode tabs 12 of at least two battery cells 10 and the total negative electrode 22.

[0075] Specifically, in the solution of this embodiment, the positive temperature coefficient thermistor 40 is configured at the negative electrode of the battery device, and the positive temperature coefficient thermistor 40 is independently configured for each battery cell 10. In more detail, in one embodiment, a positive temperature coefficient thermistor 40 may be connected in series between the negative electrode tab 12 of each battery cell 10 and the total negative electrode 22, and a positive temperature coefficient thermistor 40 may be partially or completely connected in series between the positive electrode tab 11 and the total positive electrode 21, or no positive temperature coefficient thermistor 40 may be connected in series between the positive electrode tab 11 and the total positive electrode 21.

[0076] In the above scheme, multiple positive temperature coefficient thermistors 40 are connected in series between the negative electrode tabs 12 of each battery cell 10 and the total negative electrode 22, respectively, to protect the single battery cell 10 from the negative electrode, thereby reducing the impact of the configuration of the positive temperature coefficient thermistor 40 on the volume of the single battery cell 10.

[0077] In some embodiments, the battery cell 10 is a wound battery cell 10 .

[0078] Specifically, the Jelly Roll (JR) battery cell 10 is a battery cell 10 formed by rolling the positive electrode tab 11, the negative electrode tab 12 and the separator together in a certain order and tension through the winding needle mechanism of the winding machine, which has the advantages of high energy density, good safety and strong flexibility. In this embodiment, a plurality of JR battery cells 10 are connected in parallel, the positive electrode tabs 11 of each JR battery cell 10 are connected to the total positive electrode 21, and the negative electrode tabs 12 of each JR battery cell 10 are connected to the total negative electrode 22, and charging and discharging are achieved through the positive electrode column 20 and the negative electrode column 30. In more detail, in one embodiment, the battery device is a cylindrical battery or a square shell battery.

[0079] The above solution specifically configures the positive temperature coefficient thermistor 40 in a battery device of the type of wound battery cell 10 , thereby improving the operating safety of the battery device assembled by the wound battery cell 10 .

[0080] In some embodiments, the PTC thermistor 40 is a type of PTC thermistor 40 having a transition temperature of 80° C. (Celsius) to 300° C.

[0081] Specifically, the transition temperature, i.e., the Curie temperature of the positive temperature coefficient thermistor 40, refers to the temperature point at which the resistance of the positive temperature coefficient thermistor 40 changes significantly with temperature. When the temperature is lower than the Curie temperature, the resistance of the positive temperature coefficient thermistor 40 is small, and the resistance remains basically unchanged with temperature changes; once the temperature exceeds the Curie temperature, its resistance increases sharply.

[0082] When the temperature of the battery device is below 80°C, the mechanical parts in the charge and discharge circuit can operate normally, so the transition temperature of the positive temperature coefficient thermistor can be configured to be greater than or equal to 80°C. When the temperature of the battery cell 10 is greater than 300°C, the battery cell 10 generally has a safety failure problem, and even if the positive temperature coefficient thermistor 40 is connected, it is difficult to save the failure of the battery cell 10, so the transition temperature of the positive temperature coefficient thermistor 40 can be configured to be less than or equal to 300°C.

[0083] Therefore, in actual scenarios, the transition temperature of the positive temperature coefficient thermistor 40 can be configured to 80°C-300°C, that is, a positive temperature coefficient thermistor 40 with a transition temperature of 80°C, 300°C, or any value between 80°C-300°C can be selected.

[0084] The above scheme uses a positive temperature coefficient thermistor 40 with a transition temperature of 80°C-300°C to limit the loop current of the battery device. The loop current can be limited while maintaining the normal operation of the battery cell 10, thereby improving the operating reliability of the battery device.

[0085] In some embodiments, the PTC thermistor 40 is a PTC thermistor 40 of a type having a transition temperature of 80° C. to 200° C.

[0086] Specifically, in actual scenarios, when the temperature of the battery cell 10 is greater than 300°C, the failure of the battery cell 10 will be difficult to recover. To alleviate this phenomenon, a positive temperature coefficient thermistor 40 with a transition temperature of 80°C-200°C can be used, that is, a positive temperature coefficient thermistor 40 with a transition temperature of 80°C, 200°C, or any value between 80°C-200°C can be selected. In this way, when the temperature of the battery cell 10 does not reach 300°C, the loop current can be reduced by the thermistor, thereby suppressing the increase of the temperature of the battery cell 10 and alleviating the failure of the battery cell 10.

[0087] The above scheme further uses a positive temperature coefficient thermistor 40 with a transition temperature of 80°C-200°C to limit the loop current of the battery device, thereby further improving the operating reliability and safety of the battery.

[0088] In some embodiments, the PTC thermistor 40 is a type of PTC thermistor 40 having a resistance value less than or equal to 2 mΩ (milliohm) before reaching the transition temperature.

[0089] Specifically, the thermistor is connected in series to the charge and discharge circuit, which will increase the total resistance of the charge and discharge circuit, and the polarization of the battery cell 10 is relatively large during the charge and discharge process, which reduces the energy conversion efficiency of the battery cell 10. In order to alleviate the occurrence of this phenomenon, a positive temperature coefficient thermistor 40 with a smaller resistance value when the transition temperature is not reached should be selected. Therefore, this embodiment reduces the circuit resistance and improves the energy conversion efficiency level of the battery cell 10 by selecting a positive temperature coefficient thermistor 40 with a resistance value less than or equal to 2mΩ when the transition temperature is not reached.

[0090] For example, in one embodiment, the positive temperature coefficient thermistor 40 may be selected to have a resistance value of 2 mΩ, 1.5 mΩ, 1 mΩ, etc. when the transition temperature is not reached, and this is not limited here.

[0091] The above scheme uses a positive temperature coefficient thermistor 40 of a type whose resistance value is less than or equal to 2mΩ when the transition temperature is not reached to limit the loop current of the battery device, thereby reducing the influence of the thermistor on the charge and discharge current of the battery device under normal operating conditions.

[0092] In some embodiments, the PTC thermistor 40 is a type of PTC thermistor 40 having a resistance value less than or equal to 1 mΩ before reaching the transition temperature.

[0093] Specifically, the solution of this embodiment further uses a positive temperature coefficient thermistor 40 of the type with a resistance value less than or equal to 1mΩ when the transition temperature is not reached to limit the loop current of the battery device, which can further reduce the impact of the thermistor on the charge and discharge current under normal operating conditions and improve the operating reliability of the battery device.

[0094] In order to facilitate understanding of the technical solution of the present application, the present application is explained below in conjunction with detailed embodiments.

[0095] The battery device includes a plurality of JR cells 10 connected in parallel, the positive pole tabs 11 of each JR cell 10 are connected, and the common connection point formed is used as the total positive pole 21, the total positive pole 21 is connected to the positive pole column 20, and the negative pole tabs 12 of each JR cell 10 are connected, and the common connection point formed is used as the total negative pole 22, and the total negative pole 22 is connected to the negative pole column 30. The positive temperature coefficient thermistor 40 includes a first positive temperature coefficient thermistor 41 and a second positive temperature coefficient thermistor 42, and the transition temperature of the first positive temperature coefficient thermistor 41 and the second positive temperature coefficient thermistor 42 are both 200°C. When the transition temperature is not reached, the resistance value of the first positive temperature coefficient thermistor 41 and the second positive temperature coefficient thermistor 42 is both 2mΩ. Among them, the first positive temperature coefficient thermistor 41 is connected in series between the total positive pole 21 and the positive pole column 20, and the second positive temperature coefficient thermistor 42 is connected in series between the total negative pole 22 and the negative pole column 30.

[0096] In actual operation, if the temperature detected by the first positive temperature coefficient thermistor 41 and the second positive temperature coefficient thermistor 42 does not reach 200°C, the battery device operates normally. However, when an abnormal charge and discharge behavior such as an external positive and negative short circuit, overcharging, over-discharging, etc. occurs, and the temperature detected by the first positive temperature coefficient thermistor 41 and / or the second positive temperature coefficient thermistor 42 reaches 200°C, the resistance value of the first positive temperature coefficient thermistor 41 and / or the second positive temperature coefficient thermistor 42 increases, reducing the loop current, thereby suppressing the temperature increase of the battery device.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery device, characterized in that: include: A battery cell, including a positive electrode tab and a negative electrode tab; A positive electrode post connected to the positive electrode lug, the positive electrode post being used for connecting to an external load; A negative electrode pole connected to the negative electrode tab, the negative electrode pole being used for connecting to an external load; At least two positive temperature coefficient thermistors are connected in series in a charge and discharge circuit formed by the positive electrode column, the external load, the negative electrode column, the negative electrode tab and the positive electrode tab; wherein the positive temperature coefficient thermistor is a positive temperature coefficient thermistor of the type with a transition temperature of 80°C-300°C.

2. The battery device according to claim 1, characterized in that: There are multiple battery cells, the positive pole tabs of each battery cell are connected, and the total positive pole formed is connected to the positive pole column, the negative pole tabs of each battery cell are connected, and the total negative pole formed is connected to the negative pole column, and the positive temperature coefficient thermistor is connected in series in a charging and discharging circuit formed by the total positive pole, the positive pole column, the external load, the negative pole column and the total negative pole.

3. The battery device according to claim 2, characterized in that: The positive temperature coefficient thermistor includes a first positive temperature coefficient thermistor and a second positive temperature coefficient thermistor. The total positive electrode is connected to the positive electrode column through the first positive temperature coefficient thermistor, and the total negative electrode is connected to the negative electrode column through the second positive temperature coefficient thermistor.

4. The battery device according to claim 2, characterized in that: The positive temperature coefficient thermistor includes a first positive temperature coefficient thermistor and a second positive temperature coefficient thermistor, wherein the first positive temperature coefficient thermistor is embedded in the positive electrode column, and the second positive temperature coefficient thermistor is embedded in the negative electrode column.

5. The battery device according to claim 1, characterized in that: There are multiple battery cells, the positive pole tabs of each battery cell are connected, and the total positive pole formed is connected to the positive pole column, the negative pole tabs of each battery cell are connected, and the total negative pole formed is connected to the negative pole column, the positive temperature coefficient thermistor is arranged between the positive pole tab of at least one battery cell and the total positive pole, and the positive temperature coefficient thermistor is arranged between the negative pole tab of at least one battery cell and the total negative pole.

6. The battery device according to claim 1, characterized in that: There are multiple battery cells, the positive pole tabs of each battery cell are connected, and the total positive pole formed is connected to the positive pole column, the negative pole tabs of each battery cell are connected, and the total negative pole formed is connected to the negative pole column, and the positive temperature coefficient thermistor is respectively arranged between the positive pole tabs of at least two battery cells and the total positive pole.

7. The battery device according to claim 1, characterized in that: There are multiple battery cells, the positive pole tabs of each battery cell are connected, and the total positive pole formed is connected to the positive pole column, the negative pole tabs of each battery cell are connected, and the total negative pole formed is connected to the negative pole column, and the positive temperature coefficient thermistor is respectively arranged between the negative pole tabs of at least two of the battery cells and the total negative pole.

8. The battery device according to any one of claims 1 to 7, characterized in that: The positive temperature coefficient thermistor is a positive temperature coefficient thermistor of the type with a transition temperature between 80° C. and 200° C.

9. The battery device according to any one of claims 1 to 7, characterized in that: The positive temperature coefficient thermistor is a type of positive temperature coefficient thermistor whose resistance value is less than or equal to 2 mΩ when the transition temperature is not reached.

10. The battery device according to claim 9, characterized in that: The positive temperature coefficient thermistor is a type of positive temperature coefficient thermistor whose resistance value is less than or equal to 1 mΩ when the transition temperature is not reached.

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