Plug-in type lithium battery, battery pack and equipment

Abstract

The invention discloses a plug-in type lithium battery and a battery pack, and relates to the technical field of lithium ion battery manufacturing. The plug-in type lithium battery comprises a battery body, a central channel, a positive pole, a negative pole and an anti-explosion valve, the battery body adopts a double-layer structure defined by an outer shell and an inner shell to accommodate the roll core, a central channel penetrating through two ends of the battery is defined by the inner shell, and the central channel is physically isolated from a sealed cavity for accommodating the roll core. And the positive pole and the negative pole are arranged on the end plate and are configured into detachable plugging matching structures with complementary shapes. The explosion-proof valve is configured to open to establish a pressure relief path to the central passage when the air pressure reaches a threshold. The invention aims to realize rapid grouping, disassembly and recovery of batteries through a plug-in structure, realize efficient thermal management and directional safety pressure relief by utilizing a central channel, and solve the problems of difficult heat dissipation and inconvenient recovery and disassembly of a traditional battery module.

Description

Technical Field

[0001] This invention relates to the field of lithium-ion battery manufacturing and application technology, and in particular to a plug-in lithium battery, battery pack and equipment. Background Technology

[0002] Lithium-ion batteries are widely used in electric vehicles and energy storage systems due to their high energy density and long cycle life. However, due to their electrochemical characteristics, lithium-ion batteries are quite sensitive to operating temperature, especially under conditions of low-temperature high-rate charging or high-temperature discharging, which can easily lead to lithium plating or thermal runaway risks.

[0003] In existing technologies, gases are generated inside batteries during service, leading to increased pressure. Furthermore, the stress caused by core expansion cannot be effectively monitored; the internal state is often only indirectly estimated through external voltage and current parameters, posing significant safety hazards. In addition, traditional battery pack assembly primarily relies on high-voltage connectors connected via laser welding or resistance welding. This method not only demands extremely high-precision welding equipment and processes but also makes non-destructive disassembly during battery retirement and recycling difficult, failing to meet the needs of secondary use. Once a battery experiences thermal runaway, high-temperature ejected materials can easily diffuse into the battery pack, igniting adjacent batteries and causing a chain reaction.

[0004] Therefore, designing a lithium battery that is structurally safe, has efficient thermal management capabilities, and is easy to assemble, disassemble, and recycle has become an urgent technical challenge. Summary of the Invention

[0005] The main objective of this invention is to provide a plug-in lithium battery, battery pack, and device, aiming to design a lithium battery that is structurally safe, has efficient thermal management capabilities, and is easy to assemble, disassemble, and recycle.

[0006] To achieve the above objectives, the present invention proposes a plug-in lithium battery, comprising: a battery body, including a casing, a winding core, and end plates sealing both ends of the casing; the casing includes an outer shell and an inner shell, the outer shell, the inner shell, and the end plates forming a sealed cavity for accommodating the winding core; a central channel, formed by the inner shell, defined at the center of the winding core, extending through both ends of the battery body, and physically isolated from the sealed cavity; a positive terminal and a negative terminal, disposed on the end plates, the positive terminal and the negative terminal being constructed as a detachable plug-in structure with complementary shapes; and an explosion-proof valve, disposed within the battery body, configured to open when the air pressure in the sealed cavity reaches a threshold, thereby establishing a pressure relief path from the sealed cavity to the central channel.

[0007] Preferably, one of the positive terminal and the negative terminal is convex and the other is concave; the convex terminal and the concave terminal are mechanically fastened by an interference fit or a locking structure.

[0008] Preferably, the explosion-proof valve is disposed in the connection area between the inner shell and the end plate; the central channel is configured to receive gas discharged from the sealed cavity when the explosion-proof valve is opened, and to allow the gas to contact the heat management medium flowing through the central channel.

[0009] Preferably, the battery body is cylindrical or elliptical.

[0010] Preferably, it further includes: a control unit, encapsulated inside the battery body, configured to collect operating data of the winding core; the operating data includes at least one of battery body voltage, winding core temperature, winding core stress value, winding core local displacement parameters, internal air pressure of the housing or internal gas composition of the housing.

[0011] Preferably, the control unit is further configured to communicate and interact with an external battery system control system to provide feedback on the real-time status of the battery body.

[0012] This application also discloses a battery pack, including a plurality of plug-in lithium batteries as described in any of the preceding claims; adjacent plug-in lithium batteries are directly connected in series through the plug-in mating structure of the positive terminal and the negative terminal, and the central channels of adjacent plug-in lithium batteries are interconnected to form a fluid channel through the battery pack.

[0013] Preferably, the battery pack is further equipped with an external connector, which is connected to the positive terminal or the negative terminal to achieve parallel or series connection.

[0014] This application also discloses an apparatus comprising the battery pack described above.

[0015] The above technical solution has the following advantages: This invention employs a double-shell structure with an inner and outer shell, defining a physically isolated central channel at the center of the core. This central channel serves both as an independent thermal management fluid path for direct cooling or heating of the core's center and as a directional pressure relief channel after the explosion-proof valve opens, effectively preventing the risk of thermal runaway ejections contacting the electrolyte or external electrical connection components. The complementary positive and negative electrode post structures on the end plates enable mechanical insertion and electrical connection between battery cells, eliminating traditional welding processes and significantly improving battery assembly efficiency while facilitating subsequent reuse and recycling. The combined design of the explosion-proof valve and the central channel creates an inward pressure relief mechanism. Combined with the thermal management medium flowing through the central channel, this rapidly reduces the temperature of ejected material and prevents the spread of accidents, significantly improving the overall safety of the battery cells and modules. Attached Figure Description

[0016] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings, wherein: Figure 1 This is a first-view schematic diagram of a plug-in lithium battery provided in an embodiment of the present invention.

[0017] Figure 2 This is a second-view schematic diagram of a plug-in lithium battery provided in an embodiment of the present invention.

[0018] Figure 3 This is a schematic diagram of the connection structure of the battery pack provided in an embodiment of the present invention.

[0019] 1. Negative terminal plate; 1.1 Negative terminal post; 2. Positive terminal plate; 2.1 Positive terminal post; 3. Housing; 3.1 Outer shell; 3.2 Inner shell; 4. Central channel; 5. Explosion-proof valve; 6. Control unit. Detailed Implementation

[0020] To facilitate understanding of the technical solutions of this application, detailed descriptions are provided below in conjunction with specific embodiments. It should be understood that the following specific embodiments are merely illustrative of this application and do not constitute a limitation thereof. Any equivalent structural transformations made using the specifications of this application within the inventive concept of this application, or direct or indirect applications in other related technical fields, are included within the scope of patent protection of this application.

[0021] Example 1 This embodiment provides a plug-in lithium battery, the core of which lies in the use of a unique double-layer shell structure combined with a central through-channel, which not only achieves efficient physical connection of battery cells, but also completely solves the structural contradictions of traditional battery modules in terms of thermal management and safe pressure relief.

[0022] Please see Figure 1 and Figure 2 The main structure of this plug-in lithium battery includes the battery body, which serves as the core unit for energy storage and conversion. Its external shape is preferably cylindrical or elliptical. This geometry not only conforms to the natural shape of the winding process and effectively balances the radial expansion force generated by the core during charge-discharge cycles, ensuring the uniformity of internal stress distribution and thus extending the battery's lifespan, but also facilitates high-density spatial stacking during assembly.

[0023] The battery's encapsulation structure consists of a housing 3 and negative terminal plates 1 and positive terminal plates 2 at both ends of the sealed housing 3. Specifically, the housing 3 adopts a double-layer coaxial sleeve structure, including an outer shell 3.1 and an inner shell 3.2. The outer shell 3.1 and the inner shell 3.2 are airtightly connected by the negative terminal plates 1 and positive terminal plates 2, thereby forming an annular sealed cavity between the inner wall of the outer shell 3.1, the outer wall of the inner shell 3.2, and the negative terminal plates 1 and positive terminal plates 2 at both ends. This sealed cavity is used to accommodate the core component of the electrochemical reaction, namely the winding core and the electrolyte impregnating the winding core. The winding core is wound around the outer circumferential surface of the inner shell 3.2, making full use of the annular space.

[0024] The space enclosed by the inner wall of the inner shell 3.2 is defined as the central channel 4. This central channel 4 is located on the geometric center axis of the winding core and runs through both the upper and lower ends of the battery body. It is noteworthy that, due to the physical isolation provided by the inner shell 3.2, the central channel 4 is completely isolated from the sealed cavity containing the electrolyte in physical space. This structural layout brings a significant technical advantage: the central channel 4 can serve as an independent fluid channel, allowing the introduction of cooling or heating media to achieve direct cooling or heating of the winding core, solving the problem of heat dissipation difficulties inside large cylindrical batteries. It can also serve as a dedicated path for safe pressure relief without concern about unintended chemical contact between the medium and the electrolyte.

[0025] Regarding electrical connections, the battery body has a negative terminal 1.1 and a positive terminal 2.1 at each end. The negative terminal 1.1 is located on the negative terminal plate 1, and the positive terminal 2.1 is located on the positive terminal plate 2. To enable rapid series connection between battery cells, the positive terminal 2.1 and the negative terminal 1.1 are constructed with complementary shapes for a detachable plug-in fit. In this embodiment, the positive terminal 2.1 is designed as a protruding anode head structure, while the negative terminal 1.1 is designed as a concave cathode seat structure. Of course, the protrusion / concavity relationship can be interchanged depending on the actual installation direction. This protrusion / concavity fit structure achieves mechanical fastening through interference fit or snap-fit ​​structure. For example, when two batteries are axially connected, the protruding terminal of one battery is directly inserted into the concave terminal of the other battery. The elastic deformation of the metal material generates sufficiently large contact pressure, achieving both a rigid mechanical connection and low-contact-resistance electrical series connection. This plug-in connection method eliminates the need for traditional laser welding or bolt connections, allowing battery packs to be easily disassembled by applying axial tensile force during recycling, greatly improving the convenience of reusing retired batteries.

[0026] To enhance battery safety, this embodiment also includes an explosion-proof valve 5 within the battery body. Unlike existing technologies where the explosion-proof valve is located on the surface of the outer casing 3.1 to release pressure to the external environment, this embodiment creatively places the explosion-proof valve 5 in the connection area between the inner casing 3.2 and the negative terminal plate 1 and / or the positive terminal plate 2. In a preferred embodiment, explosion-proof valves 5 are provided at both ends of the battery body to achieve bidirectional rapid pressure relief. The explosion-proof valve 5 is configured to automatically open when the gas pressure inside the sealed cavity reaches a preset threshold. This preset threshold is specifically 0.5 MPa to 1.1 MPa. Once the explosion-proof valve 5 opens, the high-temperature, high-pressure gas mainly generated by thermal runaway within the sealed cavity will directly break through the explosion-proof valve 5 and enter the physically isolated central channel 4.

[0027] This "inward pressure relief" design has profound safety implications. First, the high-temperature ejected material is confined to the controlled path of the central channel 4, preventing it from directly spraying into the internal space of the battery pack and igniting adjacent batteries or surrounding wiring harnesses. Second, when the batteries are operating in a group, the central channel 4 typically contains a liquid thermal management medium. When the high-temperature gas discharged from the sealed cavity enters the central channel 4, it immediately comes into contact with and mixes with the thermal management medium within the channel. The high specific heat capacity of the liquid medium can instantly absorb a large amount of heat, achieving rapid cooling and extinguishing of the high-temperature ejected material, thereby preventing the spread of thermal runaway at its source.

[0028] Furthermore, the plug-in lithium battery also houses a control unit 6. Located within a sealed cavity, the control unit 6 can directly contact or be at very close range sense the operating status of the winding core. The control unit 6 integrates various micro-sensors configured to collect real-time operating data of the winding core. This data specifically includes battery voltage, winding core temperature, winding core stress value, local displacement parameters of the winding core, internal air pressure of the casing, and gas composition inside the casing. For example, by monitoring the winding core stress value and local displacement parameters, it is possible to accurately determine whether lithium plating expansion or mechanical deformation has occurred inside the battery, thus providing early warning before a safety accident occurs. The control unit 6 is also equipped with a communication module, capable of transmitting the collected real-time status data to an external battery system control system, achieving intelligent management from the cell level.

[0029] Example 2 Based on Embodiment 1, this embodiment further provides a battery pack assembly, aiming to solve the technical problems of complex battery module assembly process, difficulty in disassembling and recycling welded connections, and easy diffusion of thermal runaway in the prior art.

[0030] The battery pack comprises multiple plug-in lithium batteries as described in Example 1. During assembly, the multiple plug-in lithium batteries are arranged end-to-end along an axial direction. Specifically, the positive terminal 2.1 of the preceding plug-in lithium battery is directly inserted into the complementary negative terminal 1.1 of the following plug-in lithium battery, or vice versa, achieving physical connection and series connection in the circuit through a plug-in mating structure. This connection method eliminates the need for traditional high-voltage connectors and complex laser welding processes, making the battery module assembly process similar to building with blocks, greatly reducing manufacturing energy consumption and equipment costs. More importantly, when the battery pack is retired and enters the recycling stage, only reverse mechanical force needs to be applied to disassemble each battery unit without damage, fully meeting the disassembly and assembly requirements for battery cascade utilization and environmentally friendly recycling.

[0031] As adjacent plug-in lithium batteries are connected, their respective central channels 4 naturally interconnect axially, forming a fluid channel that runs through the entire battery pack. This fluid channel has a dual function. On one hand, it constitutes a highly efficient thermal management loop. Cooling or heating media can be directly introduced into this fluid channel, flowing through the geometric center of each battery body. Since the battery center is usually the area where heat accumulates most severely, this direct cooling or heating method can control the battery temperature with the highest efficiency. For example, in low-temperature environments, the heating medium flowing through the channel can quickly heat the battery to its optimal operating range of 10°C to 30°C; under high-temperature or high-rate discharge conditions, the cooling medium can quickly remove heat from the core center, preventing localized overheating. On the other hand, this fluid channel forms a closed exhaust network. If a battery cell in a battery pack experiences thermal runaway, the high-temperature gas released by its explosion-proof valve 5 will be confined within this fluid channel and either discharged with the fluid medium within the channel or extinguished by the cooling fluid medium. This physically isolates the thermal runaway battery from the thermal radiation and flame impact on adjacent batteries, preventing arcing and the chain propagation of thermal runaway within the battery pack.

[0032] To meet different voltage and capacity requirements, the battery pack is also equipped with an external connector. One end of this external connector is designed with a plug structure that matches the positive terminal 2.1 or the negative terminal 1.1. By connecting the first and last terminals of different series branches through the external connector, parallel connection or series connection of longer paths between battery series branches can be flexibly realized, thereby freely combining the required battery module form and avoiding the limitations of the fixed structure of traditional modules.

[0033] Example 3 This embodiment focuses on the intelligent control system inside the plug-in lithium battery and the optimized selection of core materials, and is a further development of Embodiment 1 and Embodiment 2.

[0034] In this embodiment, the control unit 6, encapsulated inside the battery body, is not merely a passive data acquisition device, but rather the intelligent brain of the battery body. The control unit 6 is configured to collect real-time operating data of the winding core, which includes at least one of the following: battery body voltage, winding core temperature, winding core stress value, winding core local displacement parameters, internal air pressure of the casing, and internal gas composition of the casing.

[0035] For core temperature monitoring, control unit 6, in conjunction with the thermal management system, performs precise temperature range control. It is known that lithium-ion batteries operate relatively safely within a temperature range of 5°C to 40°C, and perform optimally within the range of 10°C to 30°C. When control unit 6 detects that the core temperature is below 0°C, it sends a heating request to the external battery system control system, introducing a heating medium through the central channel 4 to prevent lithium plating caused by high-rate charging at low temperatures. When the detected temperature is above 60°C, it sends a cooling request or cuts off the charge / discharge circuit to prevent the risk of thermal runaway.

[0036] To monitor the stress values ​​and local displacement parameters of the battery core, the control unit 6 uses miniature pressure sensors and displacement sensors to sense the physical state of the core. During charge-discharge cycles, especially when using high-energy-density negative electrode materials, the core undergoes volume expansion. In this embodiment, the core preferably uses a silicon-carbon negative electrode core, or a core structure of a solid-state battery or semi-solid-state battery. These high-energy-density systems are typically accompanied by larger volume changes. A cylindrical or elliptical cylindrical shell design can better balance the radial pressure during core expansion, ensuring the shell has maximum load-bearing capacity and minimal volume deformation. The control unit 6 monitors these stress changes in real time. Once an abnormal increase in stress value or unexpected displacement is detected, it is determined that serious lithium plating or structural damage may have occurred inside the battery, thus providing an early safety warning.

[0037] The control unit 6 is also configured to communicate with an external battery system control system. This communication can be wireless or via terminal carrier communication. The control unit 6 feeds back the processed real-time status of the battery to the system, enabling the battery management system (BMS) to manage at a granular level from the module level to the cell level, greatly improving the safety and control precision of the entire energy system.

[0038] Example 4 This embodiment provides a device that includes a battery pack as described in Embodiment 2. Specifically, this device can be an electric vehicle, an energy storage power station, a power tool, or a consumer electronics product.

[0039] Taking electric vehicles as an example, when using the plug-in lithium battery pack of this application as a power source, the electric vehicle can achieve a longer driving range and faster charging speed due to the battery pack's extremely high energy density and central heat dissipation capacity. Simultaneously, in extreme situations such as vehicle collisions, even if the battery casing is compressed, the internal explosion-proof valve 5, combined with the pressure relief mechanism of the central channel 4, can minimize the risk of battery fire and explosion, ensuring passenger safety. Furthermore, when the battery reaches the end of its lifespan and needs replacement, maintenance personnel can quickly disassemble the battery pack, reuse the healthy batteries, and recycle the materials from the scrapped batteries, significantly reducing the overall life-cycle cost and environmental impact.

[0040] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A plug-in lithium battery, characterized in that, include: The battery body includes a casing, a winding core, and end plates sealing both ends of the casing. The casing includes an outer shell and an inner shell, which, together with the end plates, form a sealed cavity to accommodate the winding core. A central channel, formed by the inner shell, is located at the center of the winding core, extends through both ends of the battery body, and is physically isolated from the sealed cavity. A positive terminal and a negative terminal are disposed on the end plates, and are configured as a detachable plug-in structure with complementary shapes. An explosion-proof valve is disposed within the battery body and configured to open when the air pressure in the sealed cavity reaches a threshold, thereby establishing a pressure relief path from the sealed cavity to the central channel.

2. The plug-in lithium battery according to claim 1, characterized in that, One of the positive and negative terminals is convex, and the other is concave; the convex terminal and the concave terminal are mechanically fastened by an interference fit or a locking structure.

3. The plug-in lithium battery according to claim 1, characterized in that, The explosion-proof valve is located in the connection area between the inner shell and the end plate; the central channel is configured to receive gas discharged from the sealed cavity when the explosion-proof valve is open, and to allow the gas to contact the heat management medium flowing through the central channel.

4. The plug-in lithium battery according to claim 1, characterized in that, The battery body is cylindrical or elliptical in shape.

5. The plug-in lithium battery according to any one of claims 1 to 4, characterized in that, Also includes: The control unit, encapsulated inside the battery body, is configured to collect the operating data of the winding core; the operating data includes at least one of the following: battery body voltage, winding core temperature, winding core stress value, winding core local displacement parameters, internal air pressure of the housing, or internal gas composition of the housing.

6. The plug-in lithium battery according to claim 5, characterized in that, The control unit is also configured to communicate and interact with an external battery system control system to provide feedback on the real-time status of the battery body.

7. A battery pack, characterized in that, It includes multiple plug-in lithium batteries as described in any one of claims 1 to 6; adjacent plug-in lithium batteries are directly connected in series through the plug-in mating structure of the positive terminal and the negative terminal, and the central channels of adjacent plug-in lithium batteries are interconnected to form a fluid channel that runs through the battery pack.

8. The battery pack according to claim 7, characterized in that, The battery pack is also equipped with an external connector, which is connected to the positive terminal or the negative terminal to achieve parallel or series connection.

9. A device, characterized in that, Includes the battery pack as described in claim 7.

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