A smart lithium battery with built-in micro sensor and manufacturing process thereof

Abstract

The application discloses a kind of intelligent lithium battery with built-in micro sensor and manufacturing process thereof, battery includes winding type electric core, battery shell, liquid injection sealing end cover, hollow insulating support skeleton is fixed in winding type electric core central cavity, multiple MEMS micro sensors and signal processing ASIC chips are fixed on the outer wall of skeleton, three composite packaging layers are covered outside chip, flexible flat lead extends along the axial direction of skeleton, and is coplanar with positive and negative pole lug from end cover heat-pressing sealing lead-out.Manufacturing process includes sensor prefabrication, skeleton assembly, winding integration, shell packaging, liquid injection formation steps, and sensing skeleton is integrated in winding core center synchronously with winding.The application does not affect the normal electrochemical performance of battery, the sensor is resistant to electrolyte corrosion, the sealing reliability is high, and is fully compatible with the existing lithium battery production line and can be mass-produced, can realize real-time monitoring of multiple parameters in battery, greatly advance thermal runaway warning time, and significantly improve the safety of lithium battery.

Description

Technical Field

[0001] This invention relates to the field of lithium battery technology, specifically to a smart lithium battery with built-in micro sensors and its manufacturing process. Background Technology

[0002] Thermal runaway in lithium-ion batteries is a core safety bottleneck restricting their large-scale application. Under conditions such as overcharging, internal short circuits, and mechanical abuse, an exothermic chain reaction will first occur inside the battery core, ultimately leading to fire and explosion. Existing battery management systems can only collect external parameters such as battery surface temperature and terminal voltage. Due to the thermal resistance of the multi-layered structure of the battery core, there is a temperature difference of 20-30°C between the internal and surface temperatures. External monitoring has a warning lag of 15-30 minutes, making it impossible to identify early signs of thermal runaway.

[0003] Existing built-in sensing solutions suffer from four inherent defects: First, the sensors embedded between the electrodes occupy the effective reaction area, hindering lithium-ion transport and resulting in a decrease in energy density of over 3% and a reduction in cycle life of 20%. Second, the sensors lack electrolyte-resistant encapsulation, making them prone to failure under prolonged operation in highly corrosive environments, and the dissolution of metal ions can also trigger battery self-discharge. Third, the leads protruding separately from the casing create weak points in the seal, leading to a leakage rate exceeding 5% after long-term cycling. Fourth, the sensor implantation process is incompatible with existing winding processes, hindering large-scale mass production. Developing a smart battery with built-in sensors that does not affect the battery's electrochemical performance, offers reliable sealing, and is mass-producible is a pressing technical problem that needs to be solved in this field. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention provides a smart lithium battery with built-in micro sensors and its manufacturing process, which can effectively solve the problems mentioned in the background technology.

[0005] The technical solution adopted by this invention to solve its technical problem is:

[0006] A smart lithium battery with built-in micro sensors includes a wound cell, a battery casing, a liquid-filled sealing end cap, and a built-in sensing component.

[0007] The wound battery cell has an axially penetrating central cavity, and a hollow insulating support frame is fixedly installed inside the central cavity.

[0008] The built-in sensing components include multiple MEMS micro-sensor chips, signal processing ASIC chips, and flexible flat leads. The multiple MEMS micro-sensor chips and signal processing ASIC chips are all fixed to the outer wall of the hollow insulating support frame with insulating adhesive, and the outer surface is covered with three composite encapsulation layers. The three composite encapsulation layers are, from the inside to the outside, a polyimide passivation layer, an alumina ceramic barrier layer, and a perfluorosulfonic acid resin protective layer.

[0009] The flexible flat lead extends along the axial direction of the hollow insulating support frame. One end is electrically connected to the signal processing ASIC chip, and the other end, together with the positive and negative tabs of the wound cell, is heat-sealed and led out to the outside of the battery from the liquid injection sealing end cap.

[0010] As a further description of the above technical solution, the hollow insulating support skeleton is a cylindrical structure made of polyetheretherketone. The outer diameter of the hollow insulating support skeleton is 2mm-4mm, and its outer wall is provided with positioning grooves that match the shape of the MEMS micro sensor chip and the signal processing ASIC chip. The MEMS micro sensor chip and the signal processing ASIC chip are embedded in the positioning grooves.

[0011] As a further description of the above technical solution, the plurality of MEMS micro sensor chips include at least an NTC temperature sensor, a MEMS piezoresistive pressure sensor, and a capacitive strain sensor.

[0012] The NTC temperature sensor is located at the axial midpoint of the hollow insulating support frame, the MEMS piezoresistive pressure sensor is located at one end of the hollow insulating support frame near the liquid injection sealing end cap, and there are two capacitive strain sensors, which are symmetrically arranged at both ends of the hollow insulating support frame near the positive and negative tabs, respectively.

[0013] As a further description of the above technical solution, the thickness of the polyimide passivation layer is 5μm-10μm, completely covering the chip surface and the pad position;

[0014] The alumina ceramic barrier layer has a thickness of 2μm-5μm and is formed by atomic layer deposition.

[0015] The thickness of the perfluorosulfonic acid resin protective layer is 15μm-20μm, and it is formed by dip coating process.

[0016] As a further description of the above technical solution, the flexible flat lead includes a polyimide substrate and copper foil conductors formed on the substrate. The copper foil conductors have a width of 0.3mm-0.5mm, a thickness of 12μm-18μm, and a spacing of 0.2mm-0.3mm between adjacent conductors.

[0017] As a further description of the above technical solution, the liquid injection sealing end cap is provided with three parallel lead-out positions. The positive electrode tab and the negative electrode tab are located at the two side lead-out positions, and the flexible flat lead wire is located at the middle lead-out position. The three are sealed by hot-pressing and fusion on the same horizontal plane with polypropylene hot melt adhesive.

[0018] As a further description of the above technical solution, the sidewall of the hollow insulating support frame is provided with multiple connecting holes, the diameter of which is 0.5mm-1mm and is evenly distributed along the axial and circumferential directions.

[0019] A manufacturing process for a smart lithium battery with built-in microsensors includes the following steps:

[0020] Step S1, Sensor Prefabrication: The MEMS micro sensor chip and the signal processing ASIC chip are mounted on one end of a flexible flat lead. After wire bonding is completed, a polyimide passivation layer and an alumina ceramic barrier layer are deposited in sequence, and a perfluorosulfonic acid resin protective layer is applied to form a prefabricated sensing module.

[0021] Step S2, skeleton assembly: Align the prefabricated sensing module with and embed it into the positioning groove on the outer wall of the hollow insulating support skeleton, apply insulating glue to fix it, and complete the preparation of the sensing skeleton assembly.

[0022] Step S3, winding integration: The sensor skeleton assembly is mounted on the winding needle of the winding machine. After stacking the positive electrode, separator and negative electrode in sequence, the winding is started, so that the sensor skeleton assembly is naturally formed in the central cavity of the wound cell during the winding process.

[0023] Step S4, casing and encapsulation: The wound cell is installed into the battery casing. The flexible flat lead wire is aligned with the positive and negative tabs and placed together at the corresponding lead-out position of the liquid injection sealing end cap. It is then heat-sealed.

[0024] Step S5, Liquid Injection and Formation: After vacuum drying, liquid injection, formation, and capacity testing, the finished smart lithium battery is obtained.

[0025] As a further description of the above technical solution, in step S3, at the beginning of winding, the diaphragm first wraps around the sensing skeleton assembly at least two turns before starting to stack the positive and negative electrode sheets. The sensing skeleton assembly and the winding needle are in a gap fit. After winding is completed, the winding needle is pulled out, and the sensing skeleton assembly is left in the center of the wound cell.

[0026] As a further description of the above technical solution, in step S4, the hot-press sealing temperature is 185℃-195℃, the pressure is 0.3MPa-0.5MPa, the pressure holding time is 8s-12s, and helium mass spectrometry leak detection is performed after the hot pressing is completed.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] The present invention provides a smart lithium battery with a built-in micro-sensor, which has at least one of the following beneficial effects during use:

[0029] By integrating sensors into a hollow insulating support frame within the core cavity, the sensor is positioned at the critical location of thermal runaway, enabling precise monitoring without occupying the effective reaction area of ​​the electrode and thus not affecting the normal electrochemical performance of the battery. This solves the problem of sensor implantation leading to battery performance degradation in existing technologies. A three-layer composite encapsulation structure provides triple protection: insulation passivation, ion barrier, and resistance to electrolyte corrosion. The sensor can operate stably in the electrolyte for extended periods without metal ion leaching and contamination of the battery system. A flat lead wire and coplanar thermo-pressed sealing structure with positive and negative tabs fundamentally eliminates the leakage risk caused by isolated lead wires, ensuring high sealing reliability. The synchronous winding integration process ensures full compatibility with existing lithium battery production lines, requiring no significant equipment modifications and making it suitable for large-scale mass production. Multi-sensor zoned arrangement enables multi-parameter collaborative monitoring, significantly advancing the thermal runaway warning time and substantially improving lithium battery safety performance. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the axial cross-sectional structure of a smart lithium battery with a built-in micro sensor according to the present invention.

[0031] Figure 2 This is a schematic diagram of the sensor skeleton axial structure of a smart lithium battery with a built-in micro sensor according to the present invention.

[0032] Figure 3 This is an enlarged schematic diagram of the packaging structure of a smart lithium battery with a built-in micro sensor according to the present invention.

[0033] Figure 4 This is a manufacturing process flow diagram of a smart lithium battery with a built-in micro-sensor according to the present invention.

[0034] Numbering on the map:

[0035] 1. Battery casing; 2. Winded cell; 3. Liquid filling and sealing end cap; 4. Hollow insulating support frame; 5. NTC temperature sensor; 6. Capacitive strain sensor; 7. MEMS piezoresistive pressure sensor; 8. Signal processing ASIC chip; 9. Flexible flat lead wire; 10. Positive tab; 11. Negative tab; 12. Frame sidewall connecting hole; 13. Sensor chip substrate; 14. Polyimide passivation layer; 15. Alumina ceramic barrier layer; 16. Perfluorosulfonic acid resin protective layer; 17. Stitching lead wire. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] like Figures 1-4 As shown, this invention provides a smart lithium battery with a built-in micro-sensor and its manufacturing process. The specific structure is as follows: a wound cell 2 is encapsulated inside a battery casing 1, and a liquid-filled sealing end cap 3 is sealed at the opening of the battery casing 1. After the wound cell 2 is wound, a central cavity is naturally formed in the center, which is axially penetrating. A hollow insulating support frame 4 is fixed in this central cavity and does not directly contact the electrode. It is naturally fixed by the winding tension, avoiding displacement of the frame and damage to the electrode during cycling.

[0038] The hollow insulating support frame 4 is made of polyetheretherketone (PEEK), a material that is resistant to electrolyte corrosion, has good insulation, high mechanical strength, and good dimensional stability, and will not release impurities inside the battery. The frame has a cylindrical structure with an outer diameter of 2mm-4mm: when the outer diameter is less than 2mm, the internal space of the frame is insufficient, making it impossible to install the sensor chip, and the frame itself is prone to deformation due to insufficient strength; when the outer diameter is greater than 4mm, it will occupy too much internal space of the winding core, reducing the battery's energy density. The wall thickness is set to 0.2mm-0.5mm: when the wall thickness is less than 0.2mm, the frame's mechanical strength is insufficient, and it is prone to deformation during winding; when the wall thickness is greater than 0.5mm, it wastes material and increases unnecessary volume. Positioning grooves are formed on the outer wall of the frame, and the sensor chip is embedded in these grooves to prevent the chip from protruding from the frame surface and being damaged by the electrode plates.

[0039] Multiple connecting holes 12 are formed on the sidewall of the core, with a diameter of 0.5mm-1mm, and are evenly distributed along the axial and circumferential directions. The function of the connecting holes is to ensure that the electrolyte can flow freely, so that the electrode at the center of the core is fully wetted, avoiding lithium plating and capacity decay caused by insufficient electrolyte in the center. When the hole diameter is less than 0.5mm, the electrolyte flow resistance is large and the wetting effect is poor; when the hole diameter is greater than 1mm, it will reduce the mechanical strength of the core.

[0040] Multiple MEMS micro-sensors and signal processing ASIC chips 8 are fixed on the outer wall of the skeleton and arranged in a partitioned manner: NTC temperature sensor 5 is located at the midpoint of the skeleton axis, which is the location where the core temperature is the highest and thermal runaway occurs earliest, and can detect internal temperature anomalies earliest; MEMS piezoresistive pressure sensor 7 is located at one end of the skeleton near the liquid injection sealing end cap 3. Gas generated in the early stage of thermal runaway will accumulate upward to the gas cavity on the end cap side, and this location can detect changes in gas generation pressure earliest; two capacitive strain sensors 6 are located at the two ends of the skeleton near the positive electrode tab 10 and the negative electrode tab 11, respectively. The root of the tab is the location where the electrode expansion stress is most concentrated, and it is also the location where electrode breakage and internal short circuit are common. The strain sensors can monitor electrode expansion deformation and provide early warning of lithium plating and electrode breakage risks.

[0041] All sensor chips are coated with a three-layer composite encapsulation layer, from the inside out: a polyimide passivation layer 14, 5μm-10μm thick, completely covering the chip surface and pads, serving as the first layer of insulation and passivation to protect the chip surface circuitry from electrolyte corrosion; a thickness less than 5μm cannot completely cover the pads and chip edges, resulting in pinhole defects; a thickness greater than 10μm affects the transmission accuracy of temperature and strain signals. An alumina ceramic barrier layer 15, 2μm-5μm thick, is formed through atomic layer deposition. This dense, pinhole-free layer completely blocks lithium ions and hydrofluoric acid penetration from the electrolyte, serving as the core anti-corrosion layer; a thickness less than 2μm results in pinhole defects and incomplete barrier function; a thickness greater than 5μm generates significant internal stress, making interlayer cracking more likely. The perfluorosulfonic acid resin protective layer 16, with a thickness of 15μm-20μm, is formed through a dip-coating process. This material is resistant to strong corrosion and has a certain degree of ion selectivity. The outermost layer directly contacts the electrolyte and can buffer the compressive stress on the chip. A thickness less than 15μm provides insufficient buffering protection, while a thickness greater than 20μm can affect the transmission of pressure signals. The three-layer encapsulation works synergistically to achieve a working life of more than 10 years for the sensor in the electrolyte.

[0042] The sensor signal is led out through a flexible flat lead wire 9. The lead wire is made of polyimide substrate, with a copper foil conductor width of 0.3mm-0.5mm, a thickness of 12μm-18μm, and a spacing of 0.2mm-0.3mm between adjacent conductors. The total thickness does not exceed 0.1mm. The flat structure is key to achieving coplanar sealing, and the thin design does not increase the thickness difference at the sealing position. The lead wire is arranged along the axis of the skeleton and parallel to the positive and negative tabs. Three parallel lead-out positions are provided on the liquid injection sealing end cap 3: the positive tab 10 and the negative tab 11 on the two sides, and the flexible flat lead wire 9 in the middle. The three are sealed by hot-pressing with polypropylene hot melt adhesive on the same horizontal plane. This structure avoids the weak points in the seal caused by separate openings for the lead wire, and the sealing reliability is consistent with the tab seal, fundamentally solving the leakage problem.

[0043] The specific manufacturing process is as follows: Step S1, sensor prefabrication: The MEMS micro-sensor chip and the signal processing ASIC chip 8 are attached to one end of the flexible flat lead 9 with conductive adhesive, and the bonding lead 17 is formed by thermo-ultrasonic bonding process to achieve electrical connection. First, polyimide adhesive is spin-coated on the chip surface, and after curing, a 5μm-10μm polyimide passivation layer 14 is formed; then, an alumina ceramic barrier layer 15 of 2μm-5μm is deposited on the surface by atomic layer deposition process; finally, the entire module is immersed in a perfluorosulfonic acid resin solution, pulled up and dried to form a 15μm-20μm perfluorosulfonic acid resin protective layer 16, completing the prefabrication of the sensor module.

[0044] Step S2, skeleton assembly: Align the prefabricated sensing module with the positioning groove on the outer wall of the hollow insulating support skeleton 4, apply electrolyte-resistant insulating epoxy glue to the groove, embed the sensing module into the groove, heat and cure to firmly fix the sensor and lead wires on the skeleton, and complete the preparation of the sensing skeleton assembly.

[0045] Step S3, Winding Integration: The assembled sensor skeleton assembly is fitted onto the winding needle of the winding machine. The skeleton and the winding needle are fitted with a gap to ensure the needle can be easily withdrawn after winding. At the start of winding, the diaphragm first wraps around the sensor skeleton assembly at least two turns to form an insulating layer, preventing the electrode from directly contacting the skeleton or sensor and causing a short circuit. Then, the positive electrode, diaphragm, and negative electrode are stacked to begin winding. During winding, the skeleton rotates synchronously with the winding needle. After winding is complete, the winding needle is withdrawn, and the sensor skeleton assembly naturally remains in the central cavity of the wound cell 2, fixed by the winding tension and will not shift.

[0046] Step S4, Encapsulation: The wound battery cell is inserted into the battery casing 1. The flexible flat lead 9, positive tab 10, and negative tab 11 are aligned and placed at the three corresponding lead-out positions on the liquid-filled sealing end cap 3. A hot-pressing process is used for sealing. The hot-pressing temperature is set to 185℃-195℃: below 185℃, the polypropylene hot melt adhesive cannot fully melt and fuse, resulting in insufficient sealing strength; above 195℃, the polypropylene adhesive will flow excessively and leak, potentially causing the tab adhesive to melt and short-circuit. The pressure is set to 0.3MPa-0.5MPa: below 0.3MPa, the adhesive layer will not bond tightly and gaps may appear; above 0.5MPa, the adhesive will be completely squeezed out, resulting in an excessively thin sealing layer. The holding time is 8s-12s: ensuring sufficient flow and fusion of the adhesive layer without causing excessive adhesive loss. After hot pressing, helium mass spectrometry leak detection is performed; the leak rate is less than [value missing]. To ensure the battery is qualified and will not leak during long-term use.

[0047] Step S5, electrolyte injection and formation: The sealed and qualified battery cells are vacuum dried at 85°C for 24 hours to remove moisture, and then injected with conventional lithium battery electrolyte. After standing and soaking, the cells undergo formation, capacity testing and inspection processes to obtain the finished smart lithium battery.

[0048] Furthermore, the hollow insulating support skeleton is made of polyetheretherketone (PEEK) because this material has good chemical stability in lithium battery electrolytes, does not dissolve impurities, and has excellent insulation and mechanical properties, making it suitable as an internal support structure.

[0049] To further explain, the sensor zoning arrangement is designed based on the thermal runaway mechanism of lithium batteries: temperature monitoring core points, pressure monitoring gas generation points, and strain monitoring stress points. The three parameters work together to cover the entire stage of thermal runaway from early lithium plating and internal short circuit to gas generation and temperature rise, achieving multi-level early warning.

[0050] To further explain, the three-layer encapsulation structure is the optimal combination verified by a large number of tests: a single polyimide encapsulation will swell in the electrolyte for a long time, a single alumina encapsulation is brittle and prone to cracking, and a single perfluorosulfonic acid encapsulation cannot block metal ions. The three-layer composite structure synergistically solves the multiple requirements of corrosion resistance, ion penetration prevention, and mechanical buffering.

[0051] Furthermore, the coplanar hot-press sealing structure overcomes the technical prejudice in this field that "leads and tabs cannot be sealed together." Through the design of the insulating substrate for flat leads, reliable insulation between leads and tabs is ensured, while the three lead positions are completed in one hot-pressing operation, resulting in good sealing consistency.

[0052] Furthermore, the synchronous winding integration process is 100% compatible with existing lithium battery winding processes. It only requires the installation of a prefabricated sensor skeleton on the winding needle, without the need for additional equipment or significant process modifications. The mass production yield can reach over 99%, solving the industry pain point that batteries with built-in sensors cannot be mass-produced.

[0053] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A smart lithium battery with a built-in micro-sensor, characterized in that: Includes wound battery cells, battery casing, liquid-filled sealing end caps, and built-in sensing components; The wound battery cell has an axially penetrating central cavity, and a hollow insulating support frame is fixedly installed inside the central cavity. The built-in sensing components include multiple MEMS micro-sensor chips, signal processing ASIC chips, and flexible flat leads. The multiple MEMS micro-sensor chips and signal processing ASIC chips are all fixed to the outer wall of the hollow insulating support frame with insulating adhesive, and the outer surface is covered with three composite encapsulation layers. The three composite encapsulation layers are, from the inside to the outside, a polyimide passivation layer, an alumina ceramic barrier layer, and a perfluorosulfonic acid resin protective layer. The flexible flat lead extends along the axial direction of the hollow insulating support frame. One end is electrically connected to the signal processing ASIC chip, and the other end, together with the positive and negative tabs of the wound cell, is heat-sealed and led out to the outside of the battery from the liquid injection sealing end cap.

2. The smart lithium battery with a built-in micro-sensor according to claim 1, characterized in that: The hollow insulating support frame is a cylindrical structure made of polyetheretherketone (PEEK). The outer diameter of the hollow insulating support frame is 2mm-4mm. Its outer wall has positioning grooves that match the shape of the MEMS micro sensor chip and the signal processing ASIC chip. The MEMS micro sensor chip and the signal processing ASIC chip are embedded in the positioning grooves.

3. The intelligent lithium battery with a built-in micro-sensor according to claim 1, characterized in that: The plurality of said MEMS micro-sensor chips include at least an NTC temperature sensor, a MEMS piezoresistive pressure sensor, and a capacitive strain sensor; The NTC temperature sensor is located at the axial midpoint of the hollow insulating support frame, the MEMS piezoresistive pressure sensor is located at one end of the hollow insulating support frame near the liquid injection sealing end cap, and there are two capacitive strain sensors, which are symmetrically arranged at both ends of the hollow insulating support frame near the positive and negative tabs, respectively.

4. A smart lithium battery with a built-in micro-sensor according to claim 1, characterized in that: The thickness of the polyimide passivation layer is 5μm-10μm, completely covering the chip surface and the pad positions; The alumina ceramic barrier layer has a thickness of 2μm-5μm and is formed by atomic layer deposition. The thickness of the perfluorosulfonic acid resin protective layer is 15μm-20μm, and it is formed by dip coating process.

5. A smart lithium battery with a built-in micro-sensor according to claim 1, characterized in that: The flexible flat lead includes a polyimide substrate and copper foil conductors formed on the substrate. The copper foil conductors have a width of 0.3mm-0.5mm, a thickness of 12μm-18μm, and a spacing of 0.2mm-0.3mm between adjacent conductors.

6. A smart lithium battery with a built-in micro-sensor according to claim 1, characterized in that: The liquid injection sealing end cap is provided with three parallel lead-out positions. The positive and negative tabs are located on the two side lead-out positions, and the flexible flat lead wire is located in the middle lead-out position. The three are sealed by hot-pressing and fusion of polypropylene hot melt adhesive on the same horizontal plane.

7. A smart lithium battery with a built-in micro-sensor according to claim 1, characterized in that: The hollow insulating support frame has multiple connecting holes on its sidewalls. The diameter of the connecting holes is 0.5mm-1mm and they are evenly distributed along the axial and circumferential directions.

8. A manufacturing process for a smart lithium battery with a built-in micro-sensor as described in any one of claims 1-7, characterized in that, Includes the following steps: Step S1, Sensor Prefabrication: The MEMS micro sensor chip and the signal processing ASIC chip are mounted on one end of a flexible flat lead. After wire bonding is completed, a polyimide passivation layer and an alumina ceramic barrier layer are deposited in sequence, and a perfluorosulfonic acid resin protective layer is applied to form a prefabricated sensing module. Step S2, skeleton assembly: Align the prefabricated sensing module with and embed it into the positioning groove on the outer wall of the hollow insulating support skeleton, apply insulating glue to fix it, and complete the preparation of the sensing skeleton assembly. Step S3, winding integration: The sensor skeleton assembly is mounted on the winding needle of the winding machine. After stacking the positive electrode, separator and negative electrode in sequence, the winding is started, so that the sensor skeleton assembly is naturally formed in the central cavity of the wound cell during the winding process. Step S4, casing and encapsulation: The wound cell is installed into the battery casing. The flexible flat lead wire is aligned with the positive and negative tabs and placed together at the corresponding lead-out position of the liquid injection sealing end cap. It is then heat-sealed. Step S5, Liquid Injection and Formation: After vacuum drying, liquid injection, formation, and capacity testing, the finished smart lithium battery is obtained.

9. The manufacturing process according to claim 8, characterized in that, In step S3, at the start of winding, the diaphragm first wraps around the sensing frame assembly at least two turns before the positive and negative electrode sheets are stacked. The sensing frame assembly and the winding needle are in a gap fit. After winding is completed, the winding needle is pulled out, and the sensing frame assembly is left in the center of the wound cell.

10. The manufacturing process according to claim 8, characterized in that, In step S4, the hot-press sealing temperature is 185℃-195℃, the pressure is 0.3MPa-0.5MPa, the pressure holding time is 8s-12s, and helium mass spectrometry leak detection is performed after hot pressing is completed.

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