Lithium ion battery and electric device

Abstract

This utility model discloses a lithium-ion battery and an electrical device. The lithium-ion battery includes two housings that surround and insulate each other to form a cavity. A battery cell is disposed within the cavity, and the battery cell includes a positive electrode unit and a negative electrode unit. The positive electrode unit and the negative electrode unit respectively have positive and negative electrode plates facing the corresponding housings. A conductive thermistor coating is applied between the positive electrode plate and the corresponding housing and / or between the negative electrode plate and the corresponding housing to electrically connect the electrode plate and the housing. This application replaces the traditional tabs with a conductive thermistor coating to conduct current, shortening the electron transmission path, reducing impedance and energy loss, and increasing energy density. Simultaneously, the conductive thermistor coating can adjust its conductivity with temperature. When the temperature rises to a set threshold, the conductivity drops sharply, quickly suppressing excessive current and preventing localized overheating. Under normal temperatures, it maintains good conductivity to ensure performance, thereby reducing the risk of thermal runaway while ensuring high energy density and improving application reliability and safety.

Description

Technical Field

[0001] This utility model relates to the field of lithium-ion battery technology, and in particular to a lithium-ion battery and electrical equipment. Background Technology

[0002] Throughout the development of electrochemical energy storage devices such as lithium-ion batteries, safety and energy density have always been the core factors restricting their large-scale application in fields such as new energy vehicles and energy storage power stations. As the demands of terminal devices for range and power output continue to increase, improving battery energy density (ED) has become one of the key research and development directions in the industry. However, the improvement of energy density is often accompanied by an increase in the risk of thermal runaway, and how to achieve a balance between the two has become a technical problem that urgently needs to be solved.

[0003] In existing lithium-ion battery structures, traditional tab designs are prone to generating significant impedance during high-current charging and discharging. This not only leads to energy loss and hinders further improvements in energy density, but may also cause abnormal heating due to localized current concentration. When the battery encounters extreme conditions such as short circuits, overcharging, or high temperatures, internal chemical reactions intensify, generating a large amount of heat. If this heat cannot be dissipated in time, it can easily lead to thermal runaway, and even cause serious safety accidents such as fires and explosions. Utility Model Content

[0004] The main purpose of this utility model is to propose a lithium-ion battery and electrical equipment, which aims to solve the technical problems of existing lithium-ion batteries, such as significant impedance, large energy loss, low energy density, and easy thermal runaway or even safety accidents caused by local heating due to the traditional tab design during high current charging and discharging.

[0005] To achieve the above objectives, this utility model proposes a lithium-ion battery, comprising:

[0006] Two housings that enclose a receiving cavity and are insulated from each other;

[0007] A battery cell is disposed in the receiving cavity. The battery cell includes a positive electrode unit and a negative electrode unit. The positive electrode unit is composed of a plurality of positive electrode plates, and the negative electrode unit is composed of a plurality of negative electrode plates. The positive electrode unit has a positive electrode plate facing one of the housings, and the negative electrode unit has a negative electrode plate facing the other housing.

[0008] A conductive thermistor coating is applied between the positive electrode and the housing corresponding to the positive electrode to electrically connect the positive electrode and the housing; and / or, the conductive thermistor coating is applied between the negative electrode and the housing corresponding to the negative electrode to electrically connect the negative electrode and the housing.

[0009] In some embodiments, the two housings are a first housing and a second housing, the positive electrode is disposed facing the first housing, and the negative electrode is disposed facing the second housing;

[0010] An insulating structure is provided between the first housing and the second housing to insulate the first housing from the second housing.

[0011] In some embodiments, the conductive thermistor coating is coated on the inner surface of the first housing facing the positive electrode, and the conductive thermistor coating is in contact with the positive electrode.

[0012] In some embodiments, the positive electrode includes a first current collector, the surface of the first current collector facing the first housing is a first empty foil area, and the conductive thermistor coating contacts the first empty foil area to achieve electrical connection.

[0013] In some embodiments, the conductive thermistor coating is coated on the inner surface of the second housing facing the negative electrode sheet, and the conductive thermistor coating is in contact with the negative electrode sheet.

[0014] In some embodiments, the negative electrode includes a second current collector, the surface of the second current collector facing the second housing is a second empty foil region, and the conductive thermistor coating contacts the second empty foil region to achieve electrical connection.

[0015] In some embodiments, a plurality of positive electrode plates of the positive electrode unit are arranged sequentially along the thickness direction of the battery cell, a plurality of negative electrode plates of the negative electrode unit are arranged sequentially along the thickness direction of the battery cell, and a separator is alternately disposed between the positive electrode plates and the negative electrode plates.

[0016] The positive electrode plate located on the outermost side of the positive electrode unit is positioned facing the first housing, and the negative electrode plate located on the outermost side of the negative electrode unit is positioned facing the second housing.

[0017] In some embodiments, the conductive thermosensitive coating is a continuous film structure or a strip structure with intervals.

[0018] In some embodiments, the thickness of the conductive thermosensitive coating is 10µm-30µm.

[0019] This utility model also provides an electrical device, including a lithium-ion battery.

[0020] This application incorporates a conductive thermistor coating between the positive electrode and its corresponding casing, and / or between the negative electrode and its corresponding casing. This conductive thermistor coating serves as the conductive connection medium between the positive electrode and the casing, and between the negative electrode and the casing, replacing traditional tabs to conduct current. This shortens the electron transport path, reduces the impedance introduced by traditional tab designs, reduces energy loss, and effectively improves battery energy density. Simultaneously, the conductive thermistor coating adjusts its conductivity according to temperature changes. When the battery temperature rises to a set threshold due to abnormal conditions, its conductivity drops sharply, quickly suppressing excessive current and preventing further localized overheating. Within the normal operating temperature range, it maintains good conductivity to ensure battery performance. Thus, while ensuring high energy density output, it establishes a temperature-responsive active safety protection mechanism, reducing the risk of thermal runaway and improving the reliability and safety of batteries in applications such as new energy vehicles and energy storage power stations. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of an embodiment of the lithium-ion battery of this utility model.

[0022] Explanation of icon numbers:

[0023] 100 Lithium-ion batteries 10 case 11 Receiving cavity 20 battery cells 21 Positive electrode unit 22 negative electrode unit 211 Positive electrode film 221 negative electrode sheet 201 diaphragm 30 Conductive thermal coating 101 First shell 102 Second shell 103 Insulation structure

[0024] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0025] The solutions in the embodiments of this utility model 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 this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0026] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0027] It should also be noted that when a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component present. When a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component present.

[0028] Furthermore, the use of terms such as "first" and "second" in this utility model is 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. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0029] Please refer to Figure 1 This application provides a lithium-ion battery 100, which includes two housings 10, a battery cell 20 and a conductive thermal coating 30. The two housings 10 enclose a cavity 11 and are insulated from each other.

[0030] The battery cell 20 is disposed in the receiving cavity 11. The battery cell 20 includes a positive electrode unit 21 and a negative electrode unit 22. The positive electrode unit 21 is composed of a plurality of positive electrode plates 211, and the negative electrode unit 22 is composed of a plurality of negative electrode plates 221. The positive electrode unit 21 has a positive electrode plate 211 facing one of the housings 10, and the negative electrode unit 22 has a negative electrode plate 221 facing the other housing 10.

[0031] A conductive thermistor coating 30 is applied between the positive electrode 211 and the housing 10 corresponding to the positive electrode 211 to electrically connect the positive electrode 211 and the corresponding housing 10; and / or, a conductive thermistor coating 30 is applied between the negative electrode 221 and the housing 10 corresponding to the negative electrode 221 to electrically connect the negative electrode 221 and the corresponding housing 10.

[0032] The two housings 10 serve as the main packaging body of the lithium-ion battery 100, forming a sealed cavity 11 to provide physical protection and a closed environment for the cell 20. The two housings 10 achieve electrical isolation through insulation connection to avoid direct conduction between the positive and negative electrodes, which could cause a short circuit. At the same time, the housings 10 serve as a carrier for current conduction, forming a complete current transmission path in conjunction with the conductive thermistor coating 30.

[0033] As the core component of the lithium-ion battery 100 for energy storage and conversion, the battery cell 20 has positive electrode unit 21 and negative electrode unit 22 completing the charging and discharging process through lithium ion insertion / extraction reaction; the stacked structure of several positive electrode plates 211 and negative electrode plates 221 improves the energy storage capacity, and multiple positive electrode plates 211 are electrically connected to each other, and multiple negative electrode plates 221 are electrically connected to each other; the positive electrode plates 211 and negative electrode plates 221 facing the housing 10 serve as the interface for the battery cell 20 to connect with the external conductive structure, ensuring the orderly output of current.

[0034] The conductive thermistor coating 30 has dual functions of conductive connection and temperature response: on the one hand, it acts as a conductive medium to directly connect the positive electrode 211 to the corresponding housing 10 and the negative electrode 221 to the corresponding housing 10, thus constructing a current transmission path to replace the traditional tab function; on the other hand, it utilizes the characteristic of its conductivity changing with temperature to maintain a low impedance conduction state when the lithium-ion battery 100 is working normally, ensuring efficient current transmission. When the internal temperature of the lithium-ion battery 100 rises abnormally to a set threshold, its conductivity drops sharply, forming current limiting protection and suppressing the risk of thermal runaway from the source.

[0035] It should be understood that the conductive thermistor coating 30 can be applied only between the positive electrode 211 and the corresponding housing 10 to achieve electrical connection between the two; or the conductive thermistor coating 30 can be applied only between the negative electrode 221 and the corresponding housing 10 to achieve electrical connection between the two; or the conductive thermistor coating 30 can be applied simultaneously between the positive electrode 211 and the corresponding housing 10, and between the negative electrode 221 and the corresponding housing 10, to achieve two electrical connections respectively. Regardless of whether it is applied only on the positive electrode side, only on the negative electrode side, or simultaneously on both positive and negative electrode sides, the conductive thermistor coating 30 can replace the traditional electrode tab to complete the current conduction on the corresponding side. At the same time, by utilizing its temperature-sensitive characteristics, it can achieve current limiting protection through its own conductivity changes when the temperature is abnormal. However, a single-sided application focuses on the conductivity and protection of the corresponding electrode side, while a dual-sided application can achieve more comprehensive conductivity optimization and safety protection. The specific implementation method can be selected according to the actual application requirements.

[0036] In this embodiment, the conductive thermistor coating 30 can be a positive temperature coefficient coating, meaning its resistance increases with temperature. It maintains a low resistance at normal operating temperatures to ensure good conductivity, and when the temperature rises to a set threshold, the resistance increases sharply, thereby quickly suppressing current and achieving overheat protection for the lithium-ion battery 100, thus meeting the temperature-responsive safety protection requirements of this application. For example, the conductive thermistor coating 30 can be a PTC coating, which can be made of existing materials such as barium titanate semiconductor ceramics.

[0037] This application embodiment provides a conductive thermistor coating 30 between the positive electrode 211 and the corresponding housing 10 and / or between the negative electrode 221 and the corresponding housing 10. The conductive thermistor coating 30 serves as a conductive connection medium between the positive electrode 211 and the housing 10, and between the negative electrode 221 and the housing 10, replacing the traditional tabs to achieve current conduction. This shortens the electron transmission path, reduces the impedance caused by the traditional tab design, reduces energy loss, and effectively improves the battery energy density. At the same time, the conductive thermistor coating 30 can adjust its conductivity according to temperature changes. When the battery temperature rises to a set threshold due to abnormal conditions, its conductivity drops sharply, which can quickly suppress excessive current and avoid aggravated local overheating. Within the normal operating temperature range, it maintains good conductivity to ensure battery performance. Thus, while ensuring high energy density output, it builds an active safety protection mechanism based on temperature response, reduces the risk of thermal runaway, and improves the reliability and safety of the battery in new energy vehicles, energy storage power stations, and other scenarios.

[0038] In some embodiments, the two housings 10 are a first housing 101 and a second housing 102, with the positive electrode 211 facing the first housing 101 and the negative electrode 221 facing the second housing 102.

[0039] An insulating structure 103 is provided between the first housing 101 and the second housing 102 to insulate the first housing 101 from the second housing 102.

[0040] The first housing 101 serves as the current-carrying carrier on the positive electrode side, and is electrically connected to the positive electrode 211 facing it through a conductive thermistor coating 30. It receives and conducts the positive electrode current, while also providing directional structural support and spatial positioning for the positive electrode 211. The second housing 102 serves as the current-carrying carrier on the negative electrode side, and is electrically connected to the negative electrode 221 facing it through a conductive thermistor coating 30. It receives and conducts the negative electrode current, while also providing directional structural support and spatial positioning for the negative electrode 221.

[0041] The insulating structure 103 is located at the connection between the first housing 101 and the second housing 102. By using its non-conductive properties, it blocks the current path between the two housings 10, thereby achieving electrical isolation between the positive and negative sides. This structurally eliminates the risk of short circuit between the housings 10, while also ensuring the airtightness of the cavity 11 formed by the two housings 10.

[0042] In this embodiment, the first housing 101 and the second housing 102 are physically connected and electrically isolated through the insulating structure 103, forming independent conductive carriers corresponding to the positive and negative sides respectively: the positive electrode 211 is oriented towards the first housing 101 and the negative electrode 221 is oriented towards the second housing 102. With the connection effect of the conductive thermistor coating 30, the current can be independently discharged through their respective housings 10, avoiding short circuits caused by direct conduction between the positive and negative electrodes. At the same time, it ensures the orderliness of the current transmission path, avoids current cross-interference, and improves the stability of current transmission.

[0043] In some embodiments, the inner surface of the first housing 101 facing the positive electrode 211 is coated with a conductive thermistor coating 30, and the conductive thermistor coating 30 is in contact with the positive electrode 211.

[0044] The conductive thermal coating 30 serves as a conductive medium between the positive electrode 211 and the first housing 101, directly receiving the current output from the positive electrode 211 and transmitting it to the first housing 101; at the same time, it serves as a temperature sensing element, capturing temperature signals in real time through contact with the positive electrode 211 and adjusting conductivity according to temperature changes.

[0045] The inner surface of the first housing 101 provides an adhesion substrate for the conductive thermal coating 30, ensuring that the conductive thermal coating 30 is stably fixed in a preset position. At the same time, it receives the conducted current through contact with the conductive thermal coating 30, thus completing the output of the positive electrode current.

[0046] The positive electrode 211 transfers current to the conductive thermistor coating 30 through contact with the conductive thermistor coating 30. At the same time, its own temperature change directly affects the conductive thermistor coating 30, triggering the adjustment of the conductivity of the conductive thermistor coating 30.

[0047] In this embodiment, the conductive thermistor coating 30 is directly coated on the inner surface of the first housing 101 and contacts the positive electrode 211, reducing the impedance of the intermediate connection links, improving current conduction efficiency, and helping to reduce energy loss. Moreover, the conductive thermistor coating 30 is fixed to the inner surface of the first housing 101 by coating, forming an integrated structure with the second housing 102, reducing the risk of loosening or falling off, ensuring the long-term stability of the conductive path and temperature sensing, and extending the service life of the lithium-ion battery 100.

[0048] In some embodiments, the positive electrode 211 includes a first current collector, the surface of the first current collector facing the first housing 101 is a first empty foil area, and the conductive thermistor coating 30 contacts the first empty foil area to achieve electrical connection.

[0049] The first empty foil region of the first current collector serves as the connection interface between the positive electrode 211 and the conductive thermistor coating 30. It achieves low-impedance current transmission by virtue of the conductive properties of the current collector (such as aluminum foil). At the same time, since it is not covered by active material, it can directly conduct the temperature signal of the positive electrode 211 to the conductive thermistor coating 30, avoiding interference from the active material layer on the electrical connection and temperature transmission.

[0050] The conductive thermal coating 30 accurately receives the positive electrode current and conducts it to the first housing 101 through direct contact with the first empty foil area. At the same time, it receives the temperature information transmitted by the first empty foil area and adjusts its own conductivity according to temperature changes to ensure the stability of current transmission and timely safety protection.

[0051] In this embodiment, the first empty foil area is the exposed portion of the metal current collector. The contact between it and the conductive thermistor coating 30 is a direct connection between the metal and the conductive material. Compared with the contact with the active material layer, the conductive resistance is lower and the connection stability is stronger, reducing impedance fluctuations caused by poor contact. Moreover, since there is no active material barrier in the first empty foil area, the actual temperature of the positive electrode 211 can be transferred to the conductive thermistor coating 30 without attenuation, making the conductive thermistor coating 30 respond to temperature changes faster and improving the timeliness of thermal runaway early warning.

[0052] In some embodiments, the inner surface of the second housing 102 facing the negative electrode 221 is coated with a conductive thermistor coating 30, and the conductive thermistor coating 30 is in contact with the negative electrode 221.

[0053] The conductive thermal coating 30 serves as a conductive medium between the negative electrode 221 and the second housing 102, receiving the current output from the negative electrode 221 and transmitting it to the second housing 102; at the same time, it serves as a temperature sensing component, acquiring temperature information in real time through contact with the negative electrode 221 and adjusting its conductivity according to temperature fluctuations.

[0054] The inner surface of the second housing 102 provides an adhesion base for the conductive thermal coating 30, ensuring that the conductive thermal coating 30 is stably positioned in a preset position. At the same time, it receives the current conducted through contact with the conductive thermal coating 30, thus completing the output of the negative electrode current.

[0055] The negative electrode 221 transmits current to the conductive thermistor coating 30 through contact with the conductive thermistor coating 30. At the same time, its own temperature change directly affects the conductive thermistor coating 30, triggering the adjustment of the conductivity of the conductive thermistor coating 30.

[0056] In this embodiment, the conductive thermistor coating 30 is directly coated on the inner surface of the second housing 102 and contacts the negative electrode 221, reducing the impedance caused by intermediate connection links, improving current conduction efficiency, and helping to reduce energy loss. Moreover, the conductive thermistor coating 30 is fixed to the inner surface of the second housing 102 by coating, forming an integral structure with the second housing 102, reducing the possibility of loosening or falling off, ensuring the long-term stability of the conductive path and temperature sensing, and helping to extend the battery's service life.

[0057] In some embodiments, the negative electrode 221 includes a second current collector, the surface of the second current collector facing the second housing 102 is a second empty foil area, and the conductive thermistor coating 30 contacts the second empty foil area to achieve electrical connection.

[0058] The second empty foil region of the second current collector serves as the connection interface between the negative electrode 221 and the conductive thermistor coating 30. It achieves low-impedance current transmission by virtue of the metallic conductivity of the current collector. At the same time, since it is not covered by active material, it can directly conduct the temperature signal of the negative electrode 221 to the conductive thermistor coating 30, avoiding interference from the active material layer on the electrical connection and temperature transmission.

[0059] The conductive thermal coating 30 accurately receives the negative electrode current and conducts it to the second housing 102 through direct contact with the second empty foil area. At the same time, it receives the temperature information transmitted by the second empty foil area and adjusts its own conductivity according to temperature changes to ensure the stability of current transmission and timely safety protection.

[0060] In this embodiment, the second empty foil area is the exposed portion of the metal current collector. The contact between it and the conductive thermistor coating 30 is a direct connection between the metal and the conductive material. Compared to contact with the negative electrode active material layer, the conductivity resistance is lower and the connection stability is better, reducing contact problems caused by active material shedding. Moreover, since there is no active material barrier in the second empty foil area, the actual temperature of the negative electrode 221 can be transferred to the coating without attenuation, making the coating respond to temperature changes faster and improving the timeliness and accuracy of thermal runaway early warning.

[0061] In some embodiments, a plurality of positive electrode plates 211 of the positive electrode unit 21 are arranged sequentially along the thickness direction of the cell 20, and a plurality of negative electrode plates 221 of the negative electrode unit 22 are arranged sequentially along the thickness direction of the cell 20, and a separator 201 is alternately disposed between the positive electrode plates 211 and the negative electrode plates 221.

[0062] The positive electrode 211 located on the outermost side of the positive electrode unit 21 is positioned facing the first housing 101, and the negative electrode 221 located on the outermost side of the negative electrode unit 22 is positioned facing the second housing 102.

[0063] In this embodiment, multiple positive electrode plates 211 of the positive electrode unit 21 and multiple negative electrode plates 221 of the negative electrode unit 22 are arranged alternately along the thickness direction of the cell 20, and a separator 201 is provided between adjacent positive electrode plates 211 and negative electrode plates 221 to achieve ion conduction and electronic isolation, forming a stacked cell 20 structure; wherein, the outermost positive electrode plate 211 of the positive electrode unit 21 is oriented towards the first housing 101, and the outermost negative electrode plate 221 of the negative electrode unit 22 is oriented towards the second housing 102, so that the current inside the cell 20 can be orderly conducted to the corresponding housing 10 through the outermost electrode plate via the conductive thermistor coating 30, and at the same time, the electrode reaction area is expanded by means of the stacked structure, thereby improving energy storage and conversion efficiency.

[0064] In this embodiment, the orderly arrangement of the multilayer electrodes along the thickness direction maximizes the utilization of the cavity 11 space, increases the loading of active material, and significantly improves the energy storage capacity of the cell 20 to meet the demand for long-lasting battery life. Furthermore, the directional arrangement of the outermost electrodes allows for concentrated current output, avoiding impedance losses caused by chaotic current paths in the multilayer electrodes, and further optimizes conductivity efficiency in conjunction with the conductive thermistor coating 30. Simultaneously, the alternating arrangement of the separator 201 ensures effective isolation between the positive electrode 211 and the negative electrode 221. Combined with the stability of the stacked structure, this reduces the risk of short circuits caused by electrode misalignment, improving the long-term reliability of the cell 20 structure.

[0065] In some embodiments, the conductive thermal coating 30 has a continuous film structure or an intermittently distributed strip structure.

[0066] The conductive thermal coating 30 is filled between the electrode and the housing 10 in a continuous film form. Through full contact, it ensures that the current is uniformly conducted between the electrode and the housing 10, reducing local current concentration. At the same time, the continuity of the film allows it to capture the overall temperature change of the electrode surface, realizing comprehensive monitoring of temperature anomalies.

[0067] In the conductive thermistor coating 30 with spaced strips, each strip independently contacts the electrode and the housing 10, respectively conducting the current in the corresponding area to form a distributed conductive path; the strip spacing design allows it to avoid special areas on the electrode surface (such as the edge of the active material layer), while multiple strip units sense the temperature at different locations, achieving accurate monitoring of local temperature.

[0068] In this embodiment, the continuous film structure has a large and uniform conductive area, which can reduce contact impedance and improve current conduction efficiency; it also provides more comprehensive monitoring of electrode temperature and can detect overall temperature anomalies in a timely manner, making it suitable for scenarios with high requirements for conductivity uniformity and comprehensive temperature monitoring.

[0069] The spaced strip structure uses less material, which helps reduce costs; it can flexibly adapt to the structural constraints of the electrode and the casing 10, and can be effectively arranged on complex surfaces; the independent working characteristics of the local strip units allow them to maintain basic conductivity and monitoring functions even when the coating fails in some areas, improving the fault tolerance of the overall structure. In particular, multiple strip structures can reduce the pulling force on the electrode when the lithium-ion battery 100 is dropped, reducing the risk of electrode damage due to external forces and improving the impact resistance and service life of the lithium-ion battery 100.

[0070] It should be understood that the two structures can be selected according to actual application needs. The continuous membrane structure focuses on high efficiency and comprehensiveness, while the strip structure focuses on economy and flexibility, which enriches the implementation methods of the technical solution and meets the performance and cost requirements of different scenarios.

[0071] In some embodiments, the thickness of the conductive thermal coating 30 is 10µm-30µm.

[0072] In this embodiment, the thickness of the conductive thermistor coating 30 is set to 10µm-30µm. This thickness range ensures that a continuous conductive network is formed inside the conductive thermistor coating 30, ensuring efficient current conduction between the electrode and the housing 10. It also enables the conductive thermistor coating 30 to have good temperature sensitivity. That is, the thinner thickness can shorten the temperature conduction path, allowing the conductive thermistor coating 30 to respond quickly to the temperature change of the electrode and adjust its conductivity in a timely manner. At the same time, it avoids the increase in impedance or temperature sensing lag caused by excessive thickness, thus achieving a balance between conductivity efficiency and temperature response speed.

[0073] For example, the thickness of the conductive thermistor coating 30 can be selected as 10µm, 20µm, or 30µm to achieve good results: at 10µm, the conductive thermistor coating 30 is thinner, the temperature conduction path is shortest, the response speed to the temperature change of the electrode is fastest, and the space occupation can be minimized, making it suitable for scenarios with extremely high requirements for temperature sensitivity and structural compactness; 20µm, as an intermediate value, can achieve a balance between the continuity of the conductive network and the temperature response speed, ensuring that the conductive particles form a stable path to reduce impedance, while also quickly sensing temperature changes, adapting to most conventional application requirements; at 30µm, the thickness of the conductive thermistor coating 30 is moderate, the conductive particles are more fully distributed, the stability of the conductive network is stronger, it can better cope with high current conduction scenarios, while still maintaining good temperature response efficiency, avoiding performance lag caused by excessive thickness.

[0074] This application also provides an electrical device, including the lithium-ion battery 100 as described above. Specifically, the electrical device can be a new energy vehicle, a storage device, a computer, a mobile phone, or other electrical equipment. This electrical device can possess all the technical features and corresponding beneficial effects of the lithium-ion battery 100 described above, which will not be elaborated further here.

[0075] The above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make other variations or modifications based on the above description. It is impossible to exhaustively list all possible implementations here. All obvious variations or modifications derived from the technical solutions of this utility model are still within the protection scope of this utility model.

Claims

1. A lithium-ion battery, characterized in that, include: Two housings that enclose a receiving cavity and are insulated from each other; A battery cell is disposed in the receiving cavity. The battery cell includes a positive electrode unit and a negative electrode unit. The positive electrode unit is composed of a plurality of positive electrode plates, and the negative electrode unit is composed of a plurality of negative electrode plates. The positive electrode unit has a positive electrode plate facing one of the housings, and the negative electrode unit has a negative electrode plate facing the other housing. A conductive thermistor coating is applied between the positive electrode and the housing corresponding to the positive electrode to electrically connect the positive electrode and the housing; and / or, the conductive thermistor coating is applied between the negative electrode and the housing corresponding to the negative electrode to electrically connect the negative electrode and the housing.

2. The lithium-ion battery according to claim 1, characterized in that, The two housings are a first housing and a second housing, with the positive electrode facing the first housing and the negative electrode facing the second housing; An insulating structure is provided between the first housing and the second housing to insulate the first housing from the second housing.

3. The lithium-ion battery according to claim 2, characterized in that, The first housing is coated with the conductive thermistor coating on its inner surface facing the positive electrode, and the conductive thermistor coating is in contact with the positive electrode.

4. The lithium-ion battery according to claim 3, characterized in that, The positive electrode includes a first current collector, the surface of the first current collector facing the first housing is a first empty foil area, and the conductive thermistor coating contacts the first empty foil area to achieve electrical connection.

5. The lithium-ion battery according to claim 2, characterized in that, The second housing has the conductive thermistor coating coated on its inner surface facing the negative electrode, and the conductive thermistor coating is in contact with the negative electrode.

6. The lithium-ion battery according to claim 5, characterized in that, The negative electrode includes a second current collector, the surface of the second current collector facing the second housing is a second empty foil area, and the conductive thermistor coating contacts the second empty foil area to achieve electrical connection.

7. The lithium-ion battery according to any one of claims 2 to 6, characterized in that, The positive electrode unit has multiple positive electrode plates arranged sequentially along the thickness direction of the battery cell, and the negative electrode unit has multiple negative electrode plates arranged sequentially along the thickness direction of the battery cell, with separators alternately disposed between the positive electrode plates and the negative electrode plates. The positive electrode plate located on the outermost side of the positive electrode unit is positioned facing the first housing, and the negative electrode plate located on the outermost side of the negative electrode unit is positioned facing the second housing.

8. The lithium-ion battery according to any one of claims 1 to 6, characterized in that, The conductive and thermosensitive coating has a continuous film structure or an intermittently distributed strip structure.

9. The lithium-ion battery according to any one of claims 1 to 6, characterized in that, The thickness of the conductive thermosensitive coating is 10um-30um.

10. An electrical appliance, characterized in that, Including the lithium-ion battery as described in any one of claims 1 to 9.

Images