Cylindrical battery including a pressure sensor, swelling pressure monitoring device, and battery management system including the device

Abstract

The present invention relates to a cylindrical battery including a pressure sensor and a swelling pressure monitoring device. A cylindrical battery according to an embodiment of the present invention includes: an electrode assembly including a first electrode, a second electrode, and a separator interposed between the first and second electrodes, wound around a winding shaft to define a core and an outer circumferential surface; a battery housing including an open end and a closed portion opposite the open end, which houses the electrode assembly in a space between the open end and the closed portion and is electrically connected to one of the first and second electrodes and has a first polarity; a sealing body which seals the open end of the battery housing; a terminal which is electrically connected to the other of the first and second electrodes and has a surface exposed to the outside and has a second polarity; and a pressure sensor which is interposed between the outer circumferential surface of the electrode assembly and the inner circumferential surface of the battery housing, which senses a swelling pressure applied by the outer circumferential surface of the electrode assembly to the inner circumferential surface of the battery housing and outputs a pressure sensing signal to the outside.

Description

[Technical Field]

[0001] The present invention relates to a cylindrical battery and a swelling pressure monitoring device, and more particularly to a cylindrical battery including a pressure sensor that senses swelling pressure applied by an electrode assembly to a battery housing and can transmit the sensing result to an external device via wireless communication, a swelling pressure monitoring device, and a battery management system including the device.

[0002] This application claims priority based on Korean Patent Application No. 2022-0107706 filed on August 26, 2022, and Korean Patent Application No. 2023-0112248 filed on August 25, 2023, and the contents disclosed in the specifications and drawings of those applications are incorporated herein in their entirety. [Background technology]

[0003] Secondary batteries, which have high applicability to each product group and electrical properties such as high energy density, are commonly used not only in portable devices but also in motor-driven electric vehicles (EVs), hybrid vehicles (HEVs), plug-in hybrid vehicles (PHEVs), and other vehicles.

[0004] Hereinafter, the term "electric vehicle" will be used to refer to a vehicle that includes an electrically driven motor, such as an EV, HEV, or PHEV.

[0005] Secondary batteries have the primary advantage of dramatically reducing the use of fossil fuels, as well as the advantage of not producing any by-products from energy use, and are therefore attracting attention as a new energy source that is environmentally friendly and can improve energy efficiency.

[0006] Currently, secondary batteries such as lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries are widely used. The operating voltage of a unit secondary battery is approximately 2.5V to 4.5V. Therefore, if a higher output voltage is required, a battery pack is constructed by connecting multiple batteries in series. Alternatively, a battery pack may be constructed by connecting multiple batteries in parallel depending on the required charge / discharge capacity of the battery pack. Therefore, the number of batteries included in the battery pack and the electrical connection configuration can be variously set depending on the required output voltage and / or charge / discharge capacity.

[0007] Meanwhile, known types of secondary batteries include cylindrical, prismatic, and pouch-type batteries. In the case of cylindrical batteries, a separator, which is an insulator, is interposed between the positive and negative electrodes and wound up to form a jelly-roll-type electrode assembly. This is then inserted into a battery housing together with an electrolyte to form a battery. Strip-shaped electrode tabs are connected to the uncoated portions of the positive and negative electrodes, electrically connecting the electrode assembly to the electrode terminals exposed on the outside. For reference, in cylindrical batteries with form factors such as 1865 and 2170, the positive terminal is a sealing cap that seals the opening of the battery housing, and the negative terminal is the battery housing.

[0008] However, conventional cylindrical batteries have problems such as high resistance, excessive heat generation, and poor current collection efficiency because current is concentrated in the strip-shaped electrode tabs connected to the positive electrode uncoated region and / or the negative electrode uncoated region.

[0009] Resistance and heat generation are not major issues with small cylindrical batteries with form factors such as 1865 and 2170. However, when the form factor of cylindrical batteries is increased to be used in electric vehicles, a large amount of heat is generated around the electrode tabs during the fast charging process, which can cause the cylindrical battery to catch fire.

[0010] To solve this problem, a cylindrical battery (so-called tab-less cylindrical battery) has been proposed, which has a structure in which positive and negative electrode uncoated areas are located at the top and bottom of a jelly-roll type electrode assembly, respectively, and current collectors are welded to these uncoated areas to improve current collection efficiency.

[0011] 1a to 1c are diagrams showing the manufacturing process of a tabless cylindrical battery. Fig. 1a shows the structure of the electrode, Fig. 1b shows the electrode winding process, and Fig. 1c shows the process of welding a current collector to the bent surface of the uncoated portion. Fig. 1d is a cross-sectional view of the tabless cylindrical battery cut in the longitudinal direction (Y axis).

[0012] 1a to 1d, the positive electrode 10 and the negative electrode 11 have a structure in which an active material 21 is coated on a sheet-shaped current collector 20, and include a plain portion 22 on one long side along the winding direction (X-axis).

[0013] The electrode assembly A is fabricated by stacking a positive electrode 10 and a negative electrode 11 together with two separators 12 in order as shown in Fig. 1b, and then winding them in one direction (X-axis direction). At this time, the uncoated portion of the positive electrode 10 and the uncoated portion of the negative electrode 11 are arranged in opposite directions.

[0014] After the winding process, the uncoated portion 10a of the positive electrode 10 and the uncoated portion 11a of the negative electrode 11 are folded toward the core. Thereafter, the current collectors 30 and 31 are welded and joined to the uncoated portions 10a and 11a, respectively.

[0015] No separate electrode tabs are attached to the positive electrode uncoated region 10a and the negative electrode uncoated region 11a, and current collectors 30 and 31 are connected to external electrode terminals, forming a current path with a large cross-sectional area along the winding axis direction of electrode assembly A (see arrow), which has the advantage of reducing battery resistance, since resistance is inversely proportional to the cross-sectional area of ​​the path through which current flows.

[0016] The electrode assembly A is inserted into the battery housing 32. The current collector 31 is welded to the bottom surface of the battery housing 32. The outer periphery of the battery housing 32 is pressed into the upper periphery of the current collector 30, forming a beading portion 33. The inner surface of the beading portion 33 presses against the periphery of the current collector 30. This secures the electrode assembly A firmly inside the battery housing 32.

[0017] After the electrode assembly A is fixed in the battery housing 32, an electrolyte is injected into the battery housing 32. Then, a cap assembly 34 is attached to the opening of the battery housing 32.

[0018] The cap assembly 34 may include a cap 34 a, a connecting plate 34 c coupled to the bottom of the cap 34 a, and a sealing gasket 34 b that seals the periphery of the cap 34 a with the open portion of the battery housing 32 .

[0019] A crimping portion 35 is provided above the beading portion 33. The crimping portion 35 is formed by bending the opening of the battery housing 32 inward, and seals the opening of the battery housing 32 by pressing the sealing gasket 34b against the peripheral surface of the cap 34a.

[0020] The current collector 30 and the connecting plate 34c may be electrically connected by a lead 30a. The lead 30a may be manufactured as a separate component and connected to the current collector 30, or may be manufactured integrally with the current collector 30 and extend to and be connected to the connecting plate 34c.

[0021] An insulator 36 is disposed on top of the current collector 30. The periphery of the insulator 36 may be interposed between the beading portion 33 and the current collector 30. As a result, the beading portion 33 presses the electrode assembly A toward the bottom of the battery housing 32 via the insulator 36.

[0022] Meanwhile, as the number of charge / discharge cycles increases, the cylindrical battery 37 experiences swelling, increasing its internal pressure. Swelling refers to the increase in the volume of the active material coated on the positive electrode 10 and negative electrode 11 as the battery is repeatedly charged and discharged. The degree of swelling is relatively greater on the negative electrode 11 side. The core of the electrode assembly A manufactured through the winding process has cavities where the core member was inserted. Therefore, when the internal pressure of the cylindrical battery 37 increases due to swelling, stress is concentrated toward the core of the electrode assembly A. This is because the battery housing is made of a highly rigid metal, and most of the stress is concentrated toward the core of the electrode assembly A, where there is empty space.

[0023] When stress occurs in the electrode assembly A due to swelling, the stress also acts in the circumferential direction, causing the positive electrode 10 and the negative electrode 11 to rotate slightly while sliding against each other via the separator. Furthermore, as the number of charge / discharge cycles increases, the amount of rotation of the positive electrode 10 and the negative electrode 11 accumulates, creating a small gap between the positive electrode 10 and the negative electrode 11 near the core, resulting in a local change in curvature. Therefore, even if the electrode assembly A has good symmetry and roundness immediately after winding, if swelling occurs, the symmetry and roundness of the electrode assembly A will change from their initial state.

[0024] Furthermore, if the swelling phenomenon worsens while the symmetry and roundness of the electrode assembly A are changed, some areas of the core of the electrode assembly A cannot withstand the stress and collapse. In the process, the separator near the collapsed area may break or microcracks may occur in the electrode, causing an internal short circuit, which is considered to be the main cause of fires inside cylindrical batteries.

[0025] 2a to 2c are cross-sectional views of the electrode assembly A, which schematically show the process of the core of the electrode assembly A collapsing. These cross-sectional views show a surface of the electrode assembly A cut perpendicular to the axial direction.

[0026] Figure 2a shows the core structure of electrode assembly A when cylindrical battery 37 is in the beginning of life (BOL) state. Steps are formed at the ends of the negative and positive electrodes, resulting in a decrease in circularity near the ends. Furthermore, when lines L1 and L2 are drawn from the center of the core through the ends of the positive and negative electrodes, respectively, the curvature of the electrode winding turns located between L1 and L2 along the circumferential direction is not constant but varies.

[0027] 2b shows that the volume of the electrodes, particularly the negative electrode, increases as the charge-discharge cycle of the cylindrical battery 37 progresses, and the negative and positive electrodes rotate around the core. The volume change of the negative electrode is greatest during the initial charge of the cylindrical battery 37 during the activation process. This is because the chemicals that cause the electrochemical reaction move from the positive electrode to the negative electrode and are inserted into the negative electrode.

[0028] The core of electrode assembly A has a hollow portion. Therefore, rotation of the electrode occurs mainly in the core. Of course, the electrode also rotates slightly on the outer periphery of electrode assembly A, but the degree of rotation is not significant compared to the core side. This is because the core of electrode assembly A has a hollow portion, so the degree of rotational freedom of the electrode when rotational stress occurs is greater than that on the outer periphery of electrode assembly A.

[0029] The increase in volume of the negative electrode is relatively greater than that of the positive electrode. Furthermore, since the positive electrode is sandwiched between the wound turns of the negative electrode near the core of electrode assembly A, a relatively greater frictional force acts on the surface of the positive electrode than on the surface of the negative electrode. Therefore, the amount of rotation of the negative electrode is greater than that of the positive electrode. The greater the volume increase, the greater the rotational stress, and the smaller the frictional force, the greater the sliding. In Figure 2b, the rotation of the positive and negative electrodes can be seen from the clockwise rotation of the core-side ends of the positive and negative electrodes. The direction in which the electrode ends rotate around the core of the electrode assembly is opposite to the winding direction.

[0030] Figure 2c shows the core structure of a cylindrical battery 37 after several hundred charge / discharge cycles and swelling. As swelling progresses, the end of the negative electrode rotates to the point where the end of the positive electrode is located. This causes the core to collapse. When the core collapses, the structure of the electrode turns, which were previously bulging outward in an arc shape like the turns of the electrodes located between 3 o'clock and 6 o'clock, changes to a shape that bulges toward the core.

[0031] If the core of electrode assembly A collapses as shown in Figure 2c, the positive electrode 10 and the negative electrode 11 cannot maintain close contact with each other, causing minute gaps at the interface between the electrodes and a sudden decrease in battery capacity. In addition, the electrode and separator near the collapsed area collapse toward the core, causing the separator to break or minute cracks to form in the electrode, which causes contact between the positive electrode 10 and the negative electrode 11 and results in an internal short circuit.

[0032] If the core of the electrode assembly A collapses, not only will the capacity of the cylindrical battery 37 decrease, but there is also a high possibility of fire due to an internal short circuit. Therefore, the use of a cylindrical battery in which the core of the electrode assembly A collapses should be discontinued immediately.

[0033] To achieve this, a technique is required that can efficiently monitor the swelling pressure that the swollen electrode assembly A applies to the inner circumferential surface of the battery housing 32 during charging and discharging of the cylindrical battery 37. Summary of the Invention [Problem to be solved by the invention]

[0034] The present invention has been made in light of the background of the prior art described above, and an object of the present invention is to provide a cylindrical battery including a pressure sensor capable of monitoring the swelling pressure that a swollen electrode assembly applies to the inner circumferential surface of a battery housing during charging and discharging of the cylindrical battery.

[0035] Another object of the present invention is to provide a cylindrical battery including a pressure sensor capable of wirelessly transmitting a pressure sensing signal to the outside, and a device capable of quantitatively monitoring the swelling pressure of a cylindrical battery using such a pressure sensor.

[0036] It is yet another object of the present invention to provide a battery pack including a cylindrical battery including a pressure sensor, and a vehicle including the battery pack.

[0037] It is yet another object of the present invention to provide a battery management system including a device for monitoring the swelling pressure of a cylindrical battery.

[0038] The technical object of the present invention is not limited to the above-mentioned object, and other objects and advantages can be understood from the following description and will become more apparent from the embodiments of the present invention. In addition, the objects and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims. [Means for solving the problem]

[0039] To achieve the above object, according to one aspect of the present invention, a cylindrical battery includes: an electrode assembly in which a core and an outer circumferential surface are defined by winding a first electrode, a second electrode, and a separator interposed between the first and second electrodes around a winding shaft; a battery housing having an open end and a closed portion opposite the open end, which houses the electrode assembly in a space between the open end and the closed portion and is electrically connected to one of the first and second electrodes and has a first polarity; a sealing body which seals the open end of the battery housing; a terminal which is electrically connected to the other of the first and second electrodes and has a surface exposed to the outside and has a second polarity; and a pressure sensor which is interposed between the outer circumferential surface of the electrode assembly and the inner circumferential surface of the battery housing and senses a swelling pressure applied by the outer circumferential surface of the electrode assembly to the inner circumferential surface of the battery housing and outputs a pressure sensing signal to the outside.

[0040] The pressure sensor may be in a sheet shape and may be bonded to the outer circumferential surface of the electrode assembly along the shape of the outer circumferential surface of the electrode assembly.

[0041] The first electrode may include a first active material portion coated with an active material layer along the winding direction and a first uncoated portion not coated with an active material layer, and the second electrode may include a second active material portion coated with an active material layer along the winding direction and a second uncoated portion not coated with an active material layer.

[0042] The first uncoated region and the second uncoated region are exposed to the outside of the separator and face each other along the winding axis direction, and may be defined as electrode tabs themselves.

[0043] When a winding turn portion disposed between a line connecting the center of the core and the core-side end of the first active material portion and a line connecting the center of the core and the core-side end of the second active material portion on a cross section of the electrode assembly perpendicular to the winding axis direction is defined as a stress-weakened region, and a winding turn portion disposed between a line connecting the center of the core and the outer circumferential end of the first active material portion and a line connecting the center of the core and the outer circumferential end of the second active material portion is defined as a stress-amplifying region, the stress-amplifying region may be separated from the stress-weakened region along the circumferential direction of the electrode assembly on the cross section.

[0044] The pressure sensor may be interposed between an outer circumferential surface of the electrode assembly and an inner circumferential surface of the battery housing so as to cover at least a portion of the stress amplification region.

[0045] The first electrode and the second electrode may be a positive electrode and a negative electrode, respectively. An outer peripheral end of the second electrode may be disposed closer to the outer periphery of the electrode assembly than an outer peripheral end of the first electrode. The separator may be interposed between the outer peripheral end of the second electrode and the outer peripheral end of the first electrode. In the circumferential direction of the electrode assembly, the outer peripheral end of the second electrode may extend beyond the outer peripheral end of the first electrode along the winding direction of the electrode assembly.

[0046] The pressure sensor may be interposed between the outer peripheral surface of the electrode assembly and the inner peripheral surface of the battery housing so as to intersect with a line connecting the center of the core and the outer peripheral end of the first electrode.

[0047] The pressure sensor may output the pressure sensing signal to the outside via wireless communication.

[0048] The pressure sensor may include an energy conversion unit that converts mechanical energy due to the swelling pressure into electrical energy; an energy storage unit that stores the converted electrical energy as a DC voltage; a pulse generation unit that receives the DC voltage from the energy storage unit and generates a pulsed surface acoustic wave; a sensing unit whose capacitance changes depending on the pressure; and a transponder that generates a reference surface acoustic wave having the same amplitude as the surface acoustic wave and a sensing surface acoustic wave having an amplitude different from the reference surface acoustic wave in accordance with the capacitance of the sensing unit and outputs the reference surface acoustic wave and the sensing surface acoustic wave through an antenna.

[0049] The cylindrical battery may further include a first bent surface region formed by bending a first uncoated portion of the first electrode toward the core, a first current collector coupled to the first bent surface region, a second bent surface region formed by bending a second uncoated portion of the second electrode toward the core, and a second current collector coupled to the second bent surface region.

[0050] The sealing body may include a cap electrically connected to the first current collector, a crimping portion that is bent in a centripetal direction of the electrode assembly while enclosing a periphery of the cap to fix the periphery of the cap to the open end of the battery housing, and a sealing gasket that is interposed between the crimping portion and the periphery of the cap to seal the open end of the battery housing.

[0051] The cylindrical battery may further include a rivet terminal that passes through a through-hole formed in a closing portion of the battery housing and is riveted to an inner surface of the closing portion, and an insulating gasket that is interposed between the rivet terminal and an inner surface of the through-hole to electrically insulate the rivet terminal from the battery housing, and the second polarity terminal may be the rivet terminal.

[0052] The cylindrical battery may further include a beading portion in which an outer peripheral surface of the battery housing adjacent to an open end of the battery housing is pressed in the winding axis direction, and at least a portion of the periphery of the second current collector may be in contact with the beading portion.

[0053] The cylindrical battery may further include a crimping portion formed by bending an open end of the battery housing in the direction of the winding axis.

[0054] The sealing body may include a cap placed on the beading portion and a sealing gasket interposed between a periphery of the cap and the open end of the battery housing, wherein one surface of the sealing gasket may be tightly fitted toward the periphery of the cap by the crimping portion, and the other surface of the sealing gasket may be tightly fitted toward the periphery of the second current collector coupled to the beading portion by the crimping portion.

[0055] The battery may have a height-to-diameter ratio greater than 0.4.

[0056] The battery form factor can be 46110, 4875, 48110, 4880 or 4680.

[0057] The above object is achieved by a battery pack including a cylindrical battery having at least one of the above-mentioned features, and a vehicle including the battery pack.

[0058] To achieve the above object, according to another aspect of the present invention, a cylindrical battery swelling pressure monitoring device may include: a receiver that receives a pressure sensing signal transmitted via wireless communication from a pressure sensor included in the cylindrical battery; a signal processor that demodulates the pressure sensing signal to an original signal; and a controller that determines the swelling pressure from the demodulated pressure sensing signal and generates time-series data of the swelling pressure.

[0059] The pressure sensor may be configured to wirelessly transmit a reference surface acoustic wave and a sensing surface acoustic wave having an amplitude different from that of the reference surface acoustic wave in response to the swelling pressure.

[0060] The control unit may be configured to determine an amplitude difference between the reference surface acoustic wave and the sensing surface acoustic wave, and to determine a swelling pressure corresponding to the determined amplitude difference using a predefined correlation between the amplitude difference and the swelling pressure.

[0061] The control unit may be configured to generate a swelling pressure profile from the time-series data of the swelling pressure, and, when at least one minimum peak is identified in the swelling pressure profile, diagnose that there is a symptom of core collapse of the electrode assembly, and output a diagnosis result.

[0062] The control unit may be configured to generate a swelling pressure profile from the time-series data of the swelling pressure, generate a differential swelling pressure profile by differentiating the swelling pressure profile with respect to time, and, when at least one peak is identified in the differential swelling pressure profile, diagnose that there is a symptom of core collapse of the electrode assembly and output a diagnosis result.

[0063] The cylindrical battery swelling pressure monitoring device may further include a voltage measuring unit that measures a voltage of the cylindrical battery.

[0064] The control unit may be configured to periodically receive voltage measurement values ​​from the voltage measurement unit to generate a voltage profile, generate a differential voltage profile by differentiating the voltage profile with time or a state of charge, and, when a swelling pressure of the cylindrical battery is equal to or greater than a critical value and at least one peak is identified in the differential voltage profile, diagnose that there is a symptom of core collapse of the electrode assembly and output a diagnosis result.

[0065] The cylindrical battery swelling pressure monitoring device may further include a display unit and / or a communication unit operably coupled to the control unit.

[0066] The control unit may be configured to output the diagnosis result through the display unit.

[0067] The control unit may be configured to transmit the diagnostic results to a computer system through the communication unit.

[0068] The diagnostic result may include a warning message or a message requesting inspection.

[0069] The above object is achieved by a battery management system including a cylindrical battery swelling pressure monitoring device including at least one of the above-mentioned features. [Effects of the Invention]

[0070] According to one aspect of the present invention, in an electrode assembly of a cylindrical battery, the relative positions of the positive electrode end and the negative electrode end on the core side and the outer periphery side are adjusted, thereby maintaining the symmetry and circularity of the electrode assembly and preventing or mitigating collapse of the core even when swelling occurs.

[0071] According to another aspect of the present invention, a cylindrical battery includes a pressure sensor capable of transmitting a pressure sensing signal via wireless communication, and continuously monitors changes in the swelling pressure applied by the outer surface of the electrode assembly to the inner surface of the battery housing, thereby easily detecting signs of core collapse.

[0072] According to another embodiment of the present invention, a battery pack manufactured using a cylindrical battery including a pressure sensor, and a vehicle including the battery pack can be provided.

[0073] According to another aspect of the present invention, there is provided a device that can monitor changes in swelling pressure that an outer surface of an electrode assembly applies to an inner surface of a battery housing during charging and discharging of a cylindrical battery, and can detect signs of core collapse of the electrode assembly, and a battery management system including the device.

[0074] The above-mentioned effects and specific effects of the present invention will be described later together with specific matters for carrying out the invention.

[0075] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention, serve to further understand the technical concept of the present invention. Therefore, the present invention should not be interpreted as being limited to only the matters described in the drawings. [Brief explanation of the drawings]

[0076] [Figure 1a] 1 is a plan view showing the structure of an electrode used in a conventional tabless cylindrical battery. [Figure 1b] 1A and 1B are diagrams illustrating a winding process of an electrode assembly included in a conventional tabless cylindrical battery. [Figure 1c] 1c is a view showing a process of welding a current collector to the bent surface of the non-coating portion in the electrode assembly of FIG. 1b. FIG. [Figure 1d] This is a cross-sectional view of a conventional tabless cylindrical battery cut in the axial direction (Y axis). [Figure 2a] 1A and 1B are cross-sectional views schematically illustrating a process in which a core of an electrode assembly according to the prior art collapses; [Figure 2b] 1A and 1B are cross-sectional views schematically illustrating a process in which a core of an electrode assembly according to the prior art collapses; [Figure 2c] 1A and 1B are cross-sectional views schematically illustrating a process in which a core of an electrode assembly according to the prior art collapses; [Figure 3] 1 is a cross-sectional view of an electrode assembly according to an embodiment of the present invention, taken perpendicular to the axial direction (Y-axis). [Figure 4] 3 is a diagram illustrating the relative positional relationship between a stress weakened region D1 and a stress amplification region D2 according to an embodiment of the present invention. FIG. [Figure 5a] 1 is a diagram showing the relative positions of a core-side end portion Ainner and an outer-periphery-side end portion Aouter of a negative electrode, and a core-side end portion Binner and an outer-periphery-side end portion Bouter of a positive electrode B according to an embodiment of the present invention. [Figure 5b] 10 is a diagram showing the relative positions of a core-side end Ainner and an outer-periphery-side end Aouter of a negative electrode, and a core-side end Binner and an outer-periphery-side end Bouter of a positive electrode B according to another embodiment of the present invention. FIG. [Figure 5c] 10 is a diagram showing the relative positions of a core-side end Ainner and an outer-periphery-side end Aouter of a negative electrode, and a core-side end Binner and an outer-periphery-side end Bouter of a positive electrode B according to still another embodiment of the present invention. FIG. [Figure 6a] 1 is a schematic cross-sectional view of a cylindrical battery including a pressure sensor Psensor according to an embodiment of the present invention, cut perpendicular to the axial direction. [Figure 6b] 1 is a schematic partial cross-sectional view of a cylindrical battery including a pressure sensor Psensor according to an embodiment of the present invention, cut along the axial direction. [Figure 6c] 1 is a diagram illustrating a configuration of a pressure sensor Psensor according to an embodiment of the present invention; [Figure 6d] FIG. 3 is a circuit diagram showing a circuit configuration of an energy storage unit according to an embodiment of the present invention. [Figure 6e]1 is a block diagram illustrating a schematic configuration of a cylindrical battery swelling pressure monitoring device according to an embodiment of the present invention; [Figure 6f] 1 is a graph illustrating an example swelling pressure profile f(t,p) according to an embodiment of the present invention. [Figure 6g] 1 is a graph illustrating a voltage profile g(t, V) according to an embodiment of the present invention. [Figure 6h] 10 is a graph illustrating a voltage profile h(SOC, V) according to another embodiment of the present invention. [Figure 7a] FIG. 2 is a plan view showing the structure of an electrode according to an embodiment of the present invention. [Figure 7b] FIG. 10 is a plan view showing the structure of an electrode according to another embodiment of the present invention. [Figure 7c] FIG. 10 is a plan view showing the structure of an electrode according to still another embodiment of the present invention. [Figure 7d] FIG. 10 is a plan view showing the structure of an electrode according to still another embodiment of the present invention. [Figure 7e] 10 is a plan view showing a modified structure of an electrode according to an embodiment of the present invention; FIG. [Figure 7f] 10 is a top view showing independent areas where multiple segments may be located when an electrode according to a modified embodiment of the present invention is wound into an electrode assembly. FIG. [Figure 8] 4 is a schematic diagram illustrating a cross section of a bent surface region formed by bending a segment toward a core of an electrode assembly according to an embodiment of the present invention; [Figure 9] 1 is a cross-sectional view of a cylindrical battery according to an embodiment of the present invention taken along the Y-axis direction. [Figure 10] 4 is a cross-sectional view of a cylindrical battery according to another embodiment of the present invention taken along the Y-axis direction. FIG. [Figure 11] FIG. 10 is a top view showing a state in which a plurality of cylindrical batteries are electrically connected. [Figure 12] FIG. 12 is a partially enlarged view of FIG. [Figure 13]1 is a diagram illustrating a schematic configuration of a battery pack and a battery management system according to an embodiment of the present invention; [Figure 14] 1 is a schematic diagram of a vehicle including a battery pack according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0077] The objects, features, and advantages of the present invention will be described in detail below with reference to the accompanying drawings, so that those skilled in the art can easily implement the technical concept of the present invention. In the description of the present invention, if a detailed description of related known technology is deemed to obscure the gist of the present invention, such detailed description will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals indicate the same or similar components.

[0078] Although terms such as "first" and "second" are used to indicate various components, these components are not limited by such terms. These terms are used merely to distinguish one component from another, and unless otherwise specified, a first component can also be a second component.

[0079] Throughout the specification, unless otherwise stated, each element may be singular or plural.

[0080] Hereinafter, when an arbitrary structure is placed "on (or under)" a component or "above (or below)" a component, it means not only that the arbitrary structure is placed in contact with the upper surface (or lower surface) of the component, but also that another structure may be interposed between the component and the arbitrary structure placed above (or below) the component.

[0081] Furthermore, when a component is referred to as being "coupled," "coupled," or "connected" to another component, this does not only mean that the components are directly coupled or connected to each other, but also that other components are "interposed" between the components, or that each component is "coupled," "coupled," or "connected" through other components.

[0082] Furthermore, as used herein, singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, terms such as "comprise" or "include" are not necessarily interpreted as including all of the components or steps described in the specification, and may mean that some of the components or steps may not be included, and that additional components or steps may also be included.

[0083] Throughout the specification, unless otherwise specified, "A and / or B" means A, B, or A and B, and "C to D" means C or more and D or less, unless otherwise specified.

[0084] For ease of explanation, in this specification, the direction along the length of the winding shaft of the electrode assembly wound into a jelly roll is referred to as the axial direction (Y-axis). Furthermore, the direction surrounding the winding shaft is referred to as the circumferential direction or outer circumferential direction (X-axis direction). Furthermore, the direction approaching or moving away from the winding shaft is referred to as the radial direction or radial direction (Z-axis direction). Of these, the direction approaching the winding shaft is particularly referred to as the centripetal direction, and the direction moving away from the winding shaft is particularly referred to as the centrifugal direction.

[0085] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0086] FIG. 3 is a cross-sectional view of an electrode assembly JR according to an embodiment of the present invention, taken perpendicular to the axial direction (Y-axis).

[0087] 3, the electrode assembly JR according to the embodiment of the present invention has a jelly roll structure in which a negative electrode A and a positive electrode B are wound around one axis with a separator S interposed therebetween. The winding direction (X-axis) is counterclockwise, but can be changed to clockwise.

[0088] A hollow portion is formed in the core C of the electrode assembly JR. The hollow portion is an empty space. There are two separators S, which are indicated by dotted lines and two-dot chain lines, respectively. The arrangement of the separators S can be varied in various ways as long as it can insulate the negative electrode A from the positive electrode B.

[0089] In the electrode assembly JR, the wound structure of the negative electrode A, positive electrode B, and separator S is shown schematically. In the actual wound structure of the electrode assembly JR, the negative electrode A, positive electrode B, and separator S are in close contact with each other.

[0090] In the electrode assembly JR, the negative electrode A is longer than the positive electrode B in the winding direction (X axis).

[0091] The winding turn of the negative electrode A begins before the winding turn of the positive electrode B. The winding turn of the positive electrode B begins after the winding turn of the negative electrode A has increased by a predetermined number of turns. The winding turn of the negative electrode A, which does not face the positive electrode B, can be 1 to 5 turns. The winding turn near the core C on which only the negative electrode A is wound reinforces the structural rigidity of the core. However, the winding turn on which only the negative electrode A is present does not contribute to the capacity of the cylindrical battery. Therefore, the number of winding turns on only the negative electrode A is appropriately selected taking into consideration the reinforcement of the structural rigidity and the capacity. Inside the winding turn consisting of only the negative electrode A, multiple winding turns consisting of only the separator S can be provided. The winding turn consisting of only the separator S can also reinforce the structural rigidity of the core.

[0092] First, a structure in which the positions of the ends of the negative electrode A and the positive electrode B are optimized to prevent or mitigate the collapse of the core of the electrode assembly JR due to rotational stress caused by the swelling phenomenon will be disclosed.

[0093] The end of the negative electrode A and the end of the positive electrode B refer to the core side end and the outer periphery side end in the wound turn structure of the negative electrode A and the positive electrode B.

[0094] For convenience of explanation, the present invention will describe an optimization embodiment for the positions of the end of the negative electrode A and the end of the positive electrode B by applying a two-dimensional polar coordinate system to a cross section perpendicular to the axial direction of the electrode assembly JR.

[0095] When a two-dimensional polar coordinate system is applied to the cross-sectional structure of the electrode assembly JR, a position within the cross-sectional structure can be expressed as the distance (r) measured from the center of the polar coordinate system to the corresponding position and the angle measured in the circumferential direction (counterclockwise) to the corresponding position based on the x-axis.

[0096] Even if the angular measurement direction of the position is changed to a clockwise direction, the technical idea of ​​the present invention can be applied substantially in the same way.

[0097] Referring to FIG. 3, the core side end A of the negative electrode A inner Angle and outer edge A outer The angles are θ A,inner and θ A,outer It can be expressed as:

[0098] Similarly, the core side end B of the positive electrode B inner Angle and outer edge B outer The angles are θ B,inner and θ B,outer It can be expressed as:

[0099] According to one embodiment, when the negative electrode A and the positive electrode B are wound in a counterclockwise direction, the core-side end A of the negative electrode A is wound as the charge-discharge cycle is repeated. inner and the core side end B of positive electrode B inner The amount of rotation is relatively large during the initial charge-discharge cycle (particularly during the activation process when the battery is fully charged), and then gradually decreases and converges to nearly zero during subsequent charge-discharge cycles.

[0100] The amount of swelling of the negative electrode A is relatively larger than that of the positive electrode B. Therefore, the core side end A of the negative electrode A inner The amount of rotation of the positive electrode B is the core side end B inner is larger than the amount of rotation.

[0101] As an example, the core side end A of negative electrode A inner The rotation amount is several tens of degrees, and the core side end B of the positive electrode B inner The amount of rotation may be less than ten degrees.

[0102] As the charge-discharge cycle is repeated, the outer edge A of the negative electrode A outer and the outer peripheral end B of the positive electrode B outer The amount of rotation is relatively large during the initial charge-discharge cycle and is small, less than a few degrees, during subsequent charge-discharge cycles.

[0103] The amount of swelling of the negative electrode A is relatively larger than that of the positive electrode B. Therefore, the amount of swelling of the outer peripheral end A of the negative electrode A is relatively larger than that of the positive electrode B. outer The amount of rotation of the positive electrode B is outer is larger than the amount of rotation.

[0104] According to another embodiment, the distance from the center of the core C of the electrode assembly JR to the core side end A of the negative electrode A inner Line L connecting A,inner and the center of the core C of the electrode assembly JR to the core side end B of the positive electrode B inner Line L connecting B,inner The wound turn portion located between and is vulnerable to stress applied to the core C side when the electrode assembly JR swells because the circularity decreases near the core C.

[0105] According to still another embodiment, the distance from the center of the core C of the electrode assembly JR to the outer peripheral end A of the negative electrode A is outer Line L connecting A,outer and the outer peripheral end B of the positive electrode B from the center of the core C of the electrode assembly JR outer Line L connecting B,outer The wound turn portion located between the positive electrode B and the core C amplifies the stress applied to the core C when the electrode assembly JR swells. outerThe wound turn portion where the electrode assembly JR is located contains the largest number of layers of electrodes and separators in the radial direction. Therefore, when the electrode assembly JR swells, the outer peripheral end B of the positive electrode B outer The wound turn portion where is located and the outer peripheral end A of the negative electrode A adjacent thereto outer This is because the area comes into contact with the battery housing H before other peripheral areas and is pressed against the battery housing H the most, thereby increasing the stress in the direction of the core C.

[0106] According to the experiment, the gap between the electrode assembly JR and the battery housing H is so small that the outer peripheral end B of the positive electrode B is already broken after one to three charge / discharge cycles. outer The wound turn portion where is located begins to contact the inner circumferential surface of the battery housing H. Also, the outer circumferential end B of the positive electrode B outer If the wound turn portion where the electrode assembly JR is located begins to contact the battery housing H, the swelling of the electrode assembly JR becomes severe, and the wound turn portion is gradually pushed toward the inner circumferential surface of the battery housing H. Therefore, as charge / discharge cycles are repeated, the outer peripheral end A of the negative electrode A outer and the outer peripheral end B of the positive electrode B outer The positive electrode B cannot rotate significantly and is substantially fixed. outer The degree of compression at the point becomes more severe, amplifying the stress at that point to the maximum.

[0107] For the sake of convenience, the line L A,inner and L B,inner The winding turn portion located between the line L and the line L is defined as the stress-weakened region D1. A,outer and L B,outer The wound turn portion located between is defined as a stress amplification region D2.

[0108] According to yet another embodiment, the stress vulnerable region D1 and the stress amplification region D2 change in angle and position over the useful life of the cylindrical battery, i.e., from BOL (Beginning of Life, at the time of shipment) to EOL (End of Life, the life required by the customer).

[0109] EOL can be defined as the number of charge / discharge cycles, and can be 200, 300, 400, 500, 600, 700, 800, 900, or more.

[0110] EOL can be defined by a capacity retention rate, such as 90%, 85%, 80%, or a capacity retention rate lower than this.

[0111] Cylindrical batteries that reach EOL can be replaced or used in other applications.

[0112] In order to prevent or mitigate collapse of the core C during the useful life of the cylindrical battery, it is preferable to optimally design the relative positions of the stress weak region D1 and the stress amplification region D2 so that the stress weak region D1 and the stress amplification region D2 are spaced apart at a predetermined angle in the circumferential direction.

[0113] Alternatively, to prevent or mitigate the collapse of the core C during the useful life of the cylindrical battery, the outer peripheral end B of the positive electrode B in the stress amplification region D2 may be outer However, it is preferable to optimally design the relative positions of the stress weakened region D1 and the stress amplification region D2 so that they are spaced apart from the stress weakened region D1 at a predetermined angle along the circumferential direction.

[0114] The relative positions of the stress-weakened region D1 and the stress-amplifying region D2 are optimized by the core-side end A of the negative electrode A. inner and the core side end B of positive electrode B inner and the outer peripheral end A of negative electrode A outer and the outer edge B of positive electrode B outer This can be done by adjusting the position of

[0115] In one embodiment, the core side end A of the negative electrode A inner and the core side end B of positive electrode B inner The angle in the circumferential direction (circumferential angle) between |θ A,inner-θ B,inner | maintains an angle of 30° to 150° throughout the life of the cylindrical battery. inner and the core side end B of positive electrode B inner The position of the ion beam can be appropriately designed.

[0116] Core side end A of negative electrode A inner and the core side end B of positive electrode B inner When designing the position of the inner , B inner The total rotation amount can be determined in advance through a charge-discharge cycle experiment of a cylindrical battery.

[0117] As a specific example, |θ A,inner -θ B,inner | maintains an angle of 40° or less, 50° or less, 60° or less, 70° or less, 80° or less, 90° or less, 100° or less, 120° or less, 130° or less, 140° or less, 150° or less, 160° or less, 170° or less, or less than 180° during the useful life of the cylindrical battery inner and the core side end B of positive electrode B inner The position of the ion beam can be appropriately designed.

[0118] In another embodiment, the core side end A of the negative electrode A inner and the core side end B of positive electrode B inner The angle in the circumferential direction (circumferential angle) between |θ A,inner -θ B,inner | converges to a specific angle selected from the range of 30° or more and less than 180° during the useful life of the cylindrical battery. inner and the core side end B of positive electrode B inner The position of the ion beam can be appropriately designed.

[0119] As a specific example, |θ A,inner -θ B,inner| converges to 30°, 40°, 50°, 60°, 70°, 80°, 90°, 100°, 110°, 120°, 130°, 140°, 150°, 160°, or 170° during the useful life of the cylindrical battery. inner and the core side end B of positive electrode B inner The position of the ion beam can be appropriately designed.

[0120] As a preferred example, |θ A,inner -θ B,inner The angle of the core side end A of the negative electrode A is preferably in the range of 110° to 130°, more preferably in the range of 115° to 125°, and even more preferably in the range of 120° during the useful life of the cylindrical battery. inner and the core side end B of positive electrode B inner The position of the ion beam can be appropriately designed.

[0121] As described above, the negative electrode A is longer in the winding direction (X axis) than the positive electrode B, and the positive electrode B is located inside the negative electrode A in the winding direction (X axis). outer Angle θ A,outer is the outer edge B of positive electrode B outer Angle θ A,outer is greater than.

[0122] That is, the outer peripheral end A of the negative electrode A outer is the outer peripheral end B of the positive electrode B outer and is located closer to the outer periphery of the electrode assembly JR than the outer periphery end B of the positive electrode B along the winding direction (X axis) in the circumferential direction. outer The outer peripheral end A of the negative electrode A can extend further beyond the outer and the outer edge B of positive electrode B outer A separation membrane S is interposed between them.

[0123] In the example, the outer peripheral end A of the negative electrode A outer Angle θ A,outer and the outer edge B of positive electrode B outer Angle θ A,outer The difference between |θ A,outer -θ B,outerThe outer edge A of the negative electrode A is rotated so that the angle of the negative electrode A is maintained within the range of 10° to 90° during the useful life of the cylindrical battery. outer and the outer peripheral end B of the positive electrode B outer The position can be designed.

[0124] When the electrode assembly JR swells (swells), in order to relieve the imbalance of stress applied to the core C side, |θ A,outer -θ B,outer | is |θ A,inner -θ B,inner can be designed to be smaller than |

[0125] As a specific example, |θ A,outer -θ B,outer | maintains an angle of 90° or less, 80° or less, 70° or less, 60° or less, 50° or less, 40° or less, 30° or less, or 20° or less during the useful life of the cylindrical battery. outer and the outer peripheral end B of the positive electrode B outer The position can be designed.

[0126] In another embodiment, the outer peripheral end A of the negative electrode A outer Angle θ A,outer and the outer edge B of positive electrode B outer Angle θ B,outer The difference between |θ A,outer -θ B,outer The outer edge A of the negative electrode A is set so that | converges to a specific angle selected from the range of 100° to 90° during the useful life of the cylindrical battery. outer and the outer peripheral end B of the positive electrode B outer The position can be designed.

[0127] As a specific example, |θ A,outer -θ B,outer | converges to an angle of 90°, 80°, 70°, 60°, 50°, 40°, 30°, 20° or 10° during the useful life of the cylindrical battery. outer and the outer peripheral end B of the positive electrode B outer The position can be designed.

[0128] As a more specific example, |θ A,outer -θ B,outer The outer peripheral end A of the negative electrode A is adjusted so that the angle of | remains between 10° and 40° during the useful life of the cylindrical battery or converges to a specific angle selected from 10° to 40°. outer and the outer peripheral end B of the positive electrode B outer The position can be designed.

[0129] FIG. 4 is a diagram for explaining the relative positional relationship between the stress weakened region D1 and the stress amplification region D2 according to an embodiment of the present invention.

[0130] 4, the stress weakened region D1 has a circumferential angle (θ1), and the stress amplification region D2 has a circumferential angle (θ2).

[0131] The line segment that divides the circumferential angle (θ1) of the stress-weakened area D1 into two equal parts is L. a and define the line segment L a When a diameter line segment O1O2 that is perpendicular to the diameter line segment O1O2 and passes through the center of the core C of the electrode assembly JR is defined as O1O2, the cross section of the electrode assembly JR can be divided into a first semicircular region CL1 and a second semicircular region CL2 that face each other based on the diameter line segment O1O2.

[0132] The closer the stress amplification region D2 is to the stress weakened region D1 in the circumferential direction, the greater the likelihood of the core C collapsing at the stress weakened region D1.

[0133] Therefore, the stress amplification region D2 is positioned within the second semicircular region CL2 defined based on the stress vulnerable region D1 even if the stress vulnerable region D1 rotates during the effective use period of the cylindrical battery. inner and the core side end B of positive electrode B inner , outer peripheral end A of negative electrode A outer and the outer edge B of positive electrode B outer The relative positions of the electrode assembly JR can be preset during the winding stage of the electrode assembly JR.

[0134] This design prevents the stress applied to the core C in the stress-weakened region D1 from increasing above a critical level due to the superposition of the stress applied to the core C in the stress-amplifying region D2. Here, the critical level may be a stress level that induces the collapse of the core C in the stress-weakened region D1.

[0135] Preferably, from the viewpoint of stress distribution, the position of the stress amplification region D2 is set so that the stress applied to the core C side in the stress fragile region D1 and the stress applied to the core C side in the stress amplification region D2 are at least partially opposed to each other.

[0136] Therefore, the stress amplification region D2 is located at the core side end A of the negative electrode A. inner and the core side end B of positive electrode B inner Even if the cylindrical battery rotates during its effective use, the stress amplification region D2 is located within the second semicircular region CL2 defined based on the stress vulnerable region D1, and a part or all of the stress amplification region D2 is located within the sector region R that is point-symmetric with the stress vulnerable region D1 around the core C. * The core side end A of negative electrode A is overlapped with inner and the core side end B of positive electrode B inner , outer peripheral end A of negative electrode A outer and the outer edge B of positive electrode B outer The relative positions of the electrode assembly JR can be preset during the winding stage of the electrode assembly JR.

[0137] Alternatively, the stress amplification region D2 is formed at the core side end A of the negative electrode A. inner and the core side end B of positive electrode B inner Even if the cylindrical battery rotates during its useful life, the positive electrode B is located within the second semicircular region CL2 defined based on the stress vulnerable region D1, and the outer peripheral end B of the positive electrode B outer is the sector area R * The core side end A of negative electrode A is positioned on the arc of the inner and the core side end B of positive electrode B inner , outer peripheral end A of negative electrode A outer and the outer edge B of positive electrode B outer The relative positions of the electrode assembly JR can be preset during the winding stage of the electrode assembly JR.

[0138] More preferably, the stress amplification region D2 is formed at the core side end A of the negative electrode A. inner and the core side end B of positive electrode B inner Even if the cylindrical battery rotates during its useful life, the stress amplification region D2 is located within the second semicircular region CL2 defined based on the stress vulnerable region D1, and the stress amplification region D2 is located within the sector region R * The core side end A of negative electrode A is aligned with the line that divides the circumference angle into two. inner and the core side end B of positive electrode B inner , outer peripheral end A of negative electrode A outer and the outer edge B of positive electrode B outer The relative positions of the electrode assembly JR can be preset during the winding stage of the electrode assembly JR.

[0139] More preferably, the stress amplification region D2 is formed at the core side end A of the negative electrode A. inner and the core side end B of positive electrode B inner Even if the cylindrical battery rotates during its useful life, the positive electrode B is located within the second semicircular region CL2 defined based on the stress vulnerable region D1, and the outer peripheral end B of the positive electrode B outer is the sector area R * The core side end A of negative electrode A is aligned with the line that divides the circumference angle of inner and the core side end B of positive electrode B inner , outer peripheral end A of negative electrode A outer and the outer edge B of positive electrode B outer The relative positions of the electrode assembly JR can be preset during the winding stage of the electrode assembly JR.

[0140] According to the above-described design, at least a portion of the stress applied to the core C side in the stress amplification region D2 opposes the stress applied to the core C side in the stress fragile region D1, thereby improving the symmetry of the stress applied to the core C side, thereby preventing the collapse of the core C or mitigating the collapse phenomenon of the core C.

[0141] According to yet another aspect of the present invention, the core side end A of the negative electrode inner and outer edge A outer , core side end B of positive electrode B inner and outer edge B outer Depending on the relative position of the positive electrode B, the outer peripheral end Bouter The rate at which the outer peripheral region of the electrode assembly corresponding to the electrode assembly contacts the inner peripheral surface of the battery housing can vary.

[0142] 5a to 5c show the core side end A of the negative electrode. inner and outer edge A outer , core side end B of positive electrode B inner and outer edge B outer 1 is a cross-sectional view of a cylindrical battery showing three embodiments of the relative positions of the battery.

[0143] The electrode assembly JR shown in FIGS. 5a to 5c has specifications that allow it to be used in a cylindrical battery with a form factor of 4680 (diameter: 46 mm, height: 80 mm).

[0144] In the cylindrical battery of FIG. 5a, when it is in a BOL state, the core side end A of the negative electrode A inner and the outer edge B of positive electrode B outer and are positioned on the same line in the radial direction of the electrode assembly JR.

[0145] In the cylindrical battery of FIG. 5b, when the battery is in a BOL state, the core side end B of the positive electrode B inner and the outer edge B of positive electrode B outer and are positioned on the same line in the radial direction of the electrode assembly JR.

[0146] In the cylindrical battery of FIG. 5c, when the battery is in the BOL state, the stress amplification region D2 is located within a second semicircular region CL2 defined based on the stress vulnerable region D1, and is point-symmetric with the stress vulnerable region D1. * It is located so as to overlap with the approximate center of the

[0147] In the cylindrical battery of FIG. 5a and the cylindrical battery of FIG. 5b, when the volume of the negative electrode A increases by about 2.5%, the outer peripheral end B of the positive electrode B outer begins to contact the inside surface of the battery housing H.

[0148] On the other hand, in the cylindrical battery shown in Figure 5c, when the volume of the negative electrode A increases by about 5% after repeated charge and discharge, the outer edge B of the positive electrode B outer begins to contact the inside surface of the battery housing H.

[0149] As in the cylindrical battery of Figure 5c, the outer edge B of the positive electrode B outer The fact that the time when the electrode assembly JR comes into contact with the inner surface of the battery housing H is delayed means that the circularity of the cross section of the electrode assembly JR is maintained relatively well.

[0150] If the circularity of the cross section of the electrode assembly is maintained relatively well, as in the cylindrical battery of Figure 5c, the possibility of core collapse can be reduced even with an increase in charge / discharge cycles compared to the cylindrical batteries of Figures 5a and 5b.

[0151] Meanwhile, the cylindrical battery according to an embodiment of the present invention includes a pressure sensor P that senses the swelling pressure that the outer surface of the electrode assembly JR applies to the inner surface of the battery housing H when the electrode assembly JR swells and provides a pressure sensing signal to the outside. sensor may include:

[0152] FIG. 6a shows a pressure sensor P according to an embodiment of the present invention. sensor 6b is a schematic cross-sectional view of a cylindrical battery including a pressure sensor P according to an embodiment of the present invention, cut perpendicular to the axial direction. sensor 1 is a schematic partial cross-sectional view of a cylindrical battery including the battery shown in FIG.

[0153] Referring to FIGS. 6a and 6b, the pressure sensor P sensor The pressure sensor P may be interposed between the outer peripheral surface of the electrode assembly JR and the battery housing H. sensor can be attached to the outer peripheral surface of the electrode assembly JR using an adhesive or adhesive tape that conforms to the shape of the outer peripheral surface of the electrode assembly JR.

[0154] Outer edge B of positive electrode outerThe area where the positive electrode is located is the area that first comes into contact with the inner circumferential surface of the battery housing H when the electrode assembly JR swells. outer The maximum swelling pressure is applied to the inner peripheral surface of the battery housing H that the battery abuts against.

[0155] In one embodiment, the pressure sensor P sensor is the center of the core of the electrode assembly JR and the outer peripheral end B of the positive electrode. outer The electrode assembly JR may be interposed between the outer peripheral surface of the electrode assembly JR and the inner peripheral surface of the battery housing H so as to intersect with the line connecting the lines.

[0156] In another embodiment, the pressure sensor P sensor is the center of the core of the electrode assembly JR and the outer peripheral end B of the positive electrode. outer and the outer peripheral end A of the negative electrode outer and the line connecting the electrode assembly JR and the battery housing H.

[0157] In yet another embodiment, the pressure sensor P sensor may be interposed between the outer peripheral surface of the electrode assembly JR and the inner peripheral surface of the battery housing H so as to overlap at least a portion of the stress amplification region (D2 in FIG. 3).

[0158] Pressure sensor P sensor Even without external power supply, the device can measure the swelling pressure that the outer circumferential surface of the electrode assembly JR applies to the inner circumferential surface of the battery housing H and transmit a pressure sensing signal to the outside via wireless communication.

[0159] FIG. 6c shows a pressure sensor P according to an embodiment of the present invention. sensor FIG. 1 is a diagram showing a schematic configuration of the

[0160] Referring to FIG. 6c, the pressure sensor P sensor is in the form of a sheet and may include an energy conversion unit 101, an energy storage unit 102, a pulse generation unit 103, a sensing unit 104, and a transponder 105.

[0161] Pressure sensor P sensor The pressure sensor P may be covered by a thin, transparent insulating film. sensor The insulating film may be sandwiched between an upper insulating film and a lower insulating film. There are no particular limitations on the insulating film, as long as it is transparent and has insulating properties. The insulating film may be a polyethylene terephthalate (PET) film or a polyimide (PI) film.

[0162] The energy conversion unit 101 is a piezoelectric power generator that converts mechanical energy due to pressure into electrical energy, and generates voltage according to the force applied to the piezoelectric body. The magnitude of the voltage is proportional to the magnitude of the applied force. The voltage generated by the energy conversion unit 101 is applied to the energy storage unit 102. The piezoelectric generator may alternatively use a conventional piezoelectric element.

[0163] The energy storage unit 102 transforms the voltage generated by the energy conversion unit 101 to a voltage of an appropriate level, rectifies it, and stores it as a DC voltage.

[0164] FIG. 6d is a circuit diagram showing the circuit configuration of the energy storage unit 102 in more detail.

[0165] 6d, the voltage generated by the energy conversion unit 101 is stepped down to an appropriate level by the transformer 102a, then full-wave rectified by the bridge rectifier 102b, and charged as a DC voltage to the capacitors C1 and 102c. The voltage charged in the capacitor C1 is boosted by the boost circuit 102d, then adjusted by the voltage adjustment unit 102e to a voltage (Vcc) capable of driving the pulse generation unit 103, and output to the pulse generation unit 103. When the capacitor C1 is charged to a predetermined level, the energy storage unit 102 discharges the stored electrical energy to drive the pulse generation unit 103. Therefore, the pulse generation unit 103 can be repeatedly driven at time intervals.

[0166] 6c, the pulse generator 103 is a voltage controlled oscillator (VCO) that generates an RF signal at an oscillation frequency adjusted according to the voltage (Vcc) output from the energy storage unit 102 and applies the RF signal to the transponder 105, thereby inducing surface acoustic waves in the transponder 105. The pulse generator 103 generates an RF signal by itself without receiving an RF signal wirelessly from an external device, thereby inducing surface acoustic waves. Preferably, the transponder 105 may be a SAW transponder.

[0167] The sensing unit 104 is a variable capacitance pressure sensing means using MEMS (Micro Electro Mechanical System) technology, and its capacitance changes in response to pressure applied from the outside, and the impedance to the sensor IDT (Interdigital Transducer) 105b of the transponder 105 changes depending on the degree of change. That is, the impedance to the sensor IDT 105b changes depending on the pressure applied to the sensing unit 104, and the amplitude of the surface acoustic wave passing through the sensor IDT 105b changes depending on the change in impedance. Therefore, the pressure applied to the sensing unit 104 can be determined by calculating the degree of change in the amplitude. Pressure sensor P sensor When the sensing portion 104 is disposed, the surface of the sensing portion 104 is preferably perpendicular to the direction in which the swelling pressure is applied.

[0168] The transponder 105 generates surface acoustic waves upon receiving an RF signal from the pulse generating unit 103, and outputs a pressure sensing signal measured by the surface acoustic waves as a wireless signal via the antenna 105e. That is, unlike conventional transponders, the transponder 105 does not generate surface acoustic waves upon receiving an RF signal from an external source, but generates electrical energy using an energy converting unit 101 provided within the sensor, and then generates an RF signal internally using the electrical energy to generate surface acoustic waves. The transponder 105 may include a number of IDT metal electrodes arranged in parallel on a substrate (LiNbO3) having piezoelectric properties.

[0169] The transponder 105 includes a launching IDT 105a, a sensor IDT 105b, a reference IDT 105c, an output IDT 105d, and an antenna 105e.

[0170] The oscillator IDT 105a receives an RF signal from the pulse generator 103, converts it into a surface acoustic wave, and outputs it to the sensor IDT 105b.

[0171] The sensor IDT 105b is electrically connected to the sensing unit 104 and is provided on a wave propagation path between the oscillator IDT 105a and the output IDT 105d, along which the surface acoustic wave generated by the oscillator IDT 105a is applied to the output IDT 105d. That is, the surface acoustic wave generated by the oscillator IDT 105a passes through the sensor IDT 105b and is applied to the output IDT 105d. At this time, if a swelling pressure is applied to the sensing unit 104 and the capacitance of the sensing unit 104 changes, the impedance of the sensor IDT 105b changes accordingly. This changes the amplitude of the surface acoustic wave passing through the sensor IDT 105b.

[0172] The reference IDT 105c is disposed opposite the oscillating IDT 105a with respect to the output IDT 105d. When an RF signal is applied from the pulse generator 103, the reference IDT 105c converts the RF signal into a surface acoustic wave and outputs it to the output IDT 105d. The surface acoustic wave generated by the reference IDT 105c has the same amplitude as the surface acoustic wave generated by the oscillating IDT 105a. The surface acoustic wave generated by the reference IDT 105c is a surface acoustic wave that serves as a reference for comparing how much the amplitude of the surface acoustic wave generated by the oscillating IDT 105a has changed in the sensor IDT 105b due to the swelling pressure applied to the sensing unit 104. Therefore, the oscillating IDT 105a and the reference IDT 105c are designed so that the surface acoustic waves generated by the two IDTs (105a, 105c) have the same amplitude. The distance between the reference IDT 105c and the output IDT 105d is designed to be shorter than the distance between the oscillation IDT 105a and the output IDT 105d.

[0173] The output IDT 105d converts the surface acoustic waves applied from the reference IDT 105c and the sensor IDT 105b into RF signals, and the converted RF signals are transmitted wirelessly to an external swelling pressure monitoring device via an antenna 105e.

[0174] The external swelling pressure monitoring device (300 in FIG. 6e) sequentially receives an RF signal corresponding to the surface acoustic wave generated by the reference IDT 105c and an RF signal corresponding to the surface acoustic wave generated by the oscillating IDT 105a, and then processes the received RF signals to compare the amplitudes, thereby quantitatively detecting the magnitude of the swelling pressure applied to the sensing unit 104.

[0175] Pressure sensor P sensorThe device operates as follows: When a swelling pressure is applied to the energy conversion unit 101, the energy conversion unit 101 converts the mechanical energy due to the swelling pressure into electrical energy and outputs it. The electrical energy generated by the energy conversion unit 101 is charged to a capacitor C1 of the energy storage unit 102. When a predetermined voltage level is charged in the capacitor C1, the energy storage unit 102 releases the stored electrical energy to the pulse generator 103 to drive the pulse generator 103.

[0176] When the pulse generator 103 receives electrical energy from the energy storage unit 102, it adjusts the oscillation frequency according to the voltage of the supplied electrical energy and generates an RF signal according to the corresponding frequency. The RF signal generated by the pulse generator 103 is applied to the reference IDT 105c and the oscillator IDT 105a, respectively.

[0177] When an RF signal is applied, the reference IDT 105c and the oscillating IDT 105a convert the RF signal into a surface acoustic wave and output it. At this time, the surface acoustic wave generated by the reference IDT 105c (hereinafter referred to as the "reference surface acoustic wave") and the surface acoustic wave generated by the oscillating IDT 105a (hereinafter referred to as the "sensing surface acoustic wave") have the same amplitude.

[0178] The reference surface acoustic wave and the sensing surface acoustic wave generated by the reference IDT 105c and the oscillator IDT 105a, respectively, are applied to the output IDT 105d. That is, the reference surface acoustic wave generated by the reference IDT 105c is applied directly to the output IDT 105d, and the surface acoustic wave generated by the oscillator IDT 105a is applied to the output IDT 105d via the sensor IDT 105b. At this time, since the distance between the reference IDT 105c and the output IDT 105d (the traveling distance of the reference surface acoustic wave) is shorter than the distance between the oscillator IDT 105a and the output IDT 105d (the traveling distance of the sensing surface acoustic wave), the reference surface acoustic wave is applied to the output IDT 105d before the sensing surface acoustic wave.

[0179] As a result, the reference surface acoustic wave generated by the reference IDT 105c is first converted into a reference RF signal by the output IDT 105d, and then wirelessly transmitted through the antenna 105e to the external swelling pressure monitoring device 300. At this time, the reference surface acoustic wave does not pass through other IDT metals during its propagation, so it maintains the waveform generated by the reference IDT 105c.

[0180] The sensing surface acoustic wave generated by the oscillator IDT 105a is then applied to the output IDT 105d, converted into a sensing RF signal, and wirelessly transmitted via the antenna 105e to the external swelling pressure monitoring device 300. Because the sensor IDT 105b is located between the oscillator IDT 105a and the output IDT 105d, the sensing surface acoustic wave, unlike the reference surface acoustic wave, changes in amplitude as it passes through the sensor IDT 105b on its way to the output IDT 105d. The degree of change in amplitude depends on the impedance of the sensor IDT 105b, i.e., the magnitude of the capacitance that changes due to the swelling pressure applied to the sensing unit 104. In other words, the capacitance of the sensing unit 104 changes depending on the magnitude of the swelling pressure applied to the sensing unit 104, and the amplitude of the sensing surface acoustic wave changes depending on the degree of this change.

[0181] The sensing surface acoustic wave, the amplitude of which has been changed by the sensor IDT 105b, is converted into a sensing RF signal by the output IDT 105d and transmitted through the antenna 105e to the external swelling pressure monitoring device 300. The external swelling pressure monitoring device 300 processes the sensing RF signal corresponding to the sensing surface acoustic wave and the reference RF signal corresponding to the previously arrived reference surface acoustic wave, and then compares the amplitudes of the two signals to calculate the difference, thereby quantitatively calculating the magnitude of the swelling pressure applied to the sensing unit 104.

[0182] FIG. 6e is a block diagram showing a schematic configuration of a cylindrical battery swelling pressure monitoring device 300 according to an embodiment of the present invention.

[0183] Referring to FIG. 6e, the cylindrical battery swelling pressure monitoring device 300 may include a receiving unit 301, a signal processing unit 302, a control unit 303, a recording unit 304, a display unit 305, and a communication unit 306.

[0184] The receiving unit 301 is a circuit that can receive an RF signal through an antenna, and is connected to the pressure sensor P sensor The pressure sensing signal includes a reference RF signal and a sensing RF signal which sequentially arrive at the antenna. sensor The signal may be repeatedly received whenever the energy storage unit 102 stores electrical energy above a certain level.

[0185] The signal processing unit 302 is a circuit that removes noise from a signal received through wireless communication and restores the original signal, and demodulates the reference RF signal and the sensing RF signal to generate a sensing surface acoustic wave and a reference surface acoustic wave, which are input to the control unit 303. The sensing surface acoustic wave and the reference surface acoustic wave are generated by the pressure sensor P sensor Here, the RF circuit technology for demodulating the RF signal to the original signal is well known in the art, so a detailed description thereof will be omitted.

[0186] The control unit 303 is a circuit that generally controls the cylindrical battery swelling pressure monitoring device 300. The control unit 303 may determine the amplitude of a sensing surface acoustic wave and the amplitude of a reference surface acoustic wave through signal processing, and determine the difference between the two amplitudes. The control unit 303 may also determine the swelling pressure corresponding to the difference between the two amplitudes by referring to a lookup table that predefines swelling pressures according to the difference between the amplitude of the sensing surface acoustic wave and the amplitude of the reference surface acoustic wave. The lookup table may be pre-recorded in the recording unit 304 and referenced by the control unit 303.

[0187] The control unit 303 may also accumulate and record the determined swelling pressures together with timestamps in the recording unit 304, thereby generating time-series data of the swelling pressure in the recording unit 304. The length of the time interval during which the time-series data of the swelling pressure is generated may be set arbitrarily. The control unit 303 may also generate a swelling pressure profile using the time-series data of the swelling pressure generated in the recording unit 304.

[0188] 6f is a graph illustrating a swelling pressure profile f(t,p) according to an embodiment of the present invention, where t represents time and p is a variable representing swelling pressure.

[0189] Referring to the swelling pressure profile f(t,p) shown in FIG. 6f, the swelling pressure gradually increases over time and reaches a saturation point. The section where the swelling pressure increases is the section where the battery housing H elastically deforms due to the swelling of the electrode assembly JR, increasing the outer diameter of the battery housing H. Meanwhile, the section after the swelling pressure reaches a saturation point is the section where the battery housing H undergoes plastic deformation as the swelling of the electrode assembly JR deepens. If the battery housing H undergoes plastic deformation, it will not return to its original shape even if the electrode assembly JR is removed from the battery housing H.

[0190] The core collapse phenomenon of the electrode assembly JR may occur after the swelling pressure reaches a saturated state in the swelling pressure profile f(t,p). Signs of core collapse of the electrode assembly JR may be detected by an abnormal pattern, as shown by the dotted line profile, in which the swelling pressure suddenly decreases in a short period of time and then gradually increases again. That is, if at least one minimum peak is identified in the swelling pressure profile f(t,p), it can be diagnosed as a sign of core collapse of the electrode assembly JR. This is because signs of core collapse of the electrode assembly JR occur when the stress in the electrode assembly JR decreases slightly and the swelling pressure suddenly and minutely decreases in a short period of time. Therefore, the control unit 303 can detect signs of core collapse of the electrode assembly JR in advance using the swelling pressure profile f(t,p).

[0191] In one embodiment, the control unit 303 may generate a swelling pressure profile f(t,p) as shown in Fig. 6f using the time-series data of the swelling pressure periodically generated in the recording unit 304. Furthermore, when at least one minimum peak is identified from the swelling pressure profile f(t,p), the control unit 303 may diagnose that there is a symptom of core collapse of the electrode assembly JR and output the diagnosis result.

[0192] In another embodiment, the control unit 303 may generate a differential swelling pressure profile f′(t,p) through time differentiation of the swelling pressure profile f(t,p) as shown in FIG. diag If a minimum peak appears at time t, the differential swelling pressure profile f'(t,p) diag Moving forward and backward in time, t diag,1 A minimum peak appears at time t diag,2 A maximum peak may appear at time t. In the swelling pressure profile f(t,p), a minimum peak appears at time t. diag t diag,1 time and t diag,2This is because an inflection point occurs at time t. Therefore, when at least one peak is identified from the differential swelling pressure profile f′(t,p), the control unit 303 may diagnose that there is a symptom of core collapse of the electrode assembly JR and output the diagnosis result. diag earlier than time t diag,1 At this point, signs of core collapse of the electrode assembly JR can be detected.

[0193] In yet another embodiment, the control unit 303 can simultaneously monitor not only the swelling pressure but also the battery voltage to detect signs of core collapse of the electrode assembly JR in advance. To this end, the cylindrical battery swelling pressure monitoring device 300 may further include a voltage measurement unit 307. The voltage measurement unit 307 includes a voltage measurement circuit known in the art.

[0194] The control unit 303 periodically receives input of voltage measurement values ​​from the voltage measurement unit 307 and accumulates and records the values ​​together with timestamps in the recording unit 304, thereby generating time-series data of voltage in the recording unit 304. The length of the time interval during which the time-series data of voltage is generated can be set arbitrarily.

[0195] The control unit 303 can generate a voltage profile g(t, V) using the time-series data of voltage periodically generated in the recording unit 304. In g(t, V), t represents time, and V is a variable representing voltage.

[0196] FIG. 6g is a graph illustrating an example voltage profile g(t,V) according to an embodiment of the present invention.

[0197] The control unit 303 can generate a differential voltage profile g′(t,V) by time-differentiating the voltage profile g(t,V).

[0198] The control unit 303 can detect in advance the signs of core collapse of the electrode assembly JR by using the periodically generated differential voltage profile g'(t, V).

[0199] That is, the control unit 303 may refer to the time-series data of the swelling pressure generated in the recording unit 304, and when the conditions that the swelling pressure at the current time point is equal to or greater than a predetermined critical value and at least one peak is identified from the differential voltage profile g'(t, V) are satisfied, the control unit 303 may diagnose that there is a symptom of core collapse of the electrode assembly JR, and output the diagnosis result.

[0200] In this embodiment, signs of core collapse of the electrode assembly JR can be detected in advance more quickly than when signs of core collapse of the electrode assembly JR are detected using the swelling pressure profile f(t,p) or the differential swelling pressure profile f'(t,p). This is because when signs of core collapse of the electrode assembly JR occur, before a change in swelling pressure appears, the adhesion between the electrodes and the separator near the core deteriorates, reducing the effective area where an electrochemical reaction occurs, which can cause the battery voltage to slightly decrease and then increase, as shown by the dotted line profile in Figure 6g.

[0201] Such minute voltage changes can be detected by monitoring whether or not a peak appears in the differential voltage profile g'(t, V). For example, as shown in Figure 6g, * diag If a minute voltage decrease pattern occurs in the voltage profile g(t,V) at time t, the differential voltage profile g'(t,V) * diag Moving forward and backward in time, t * diag,1 A minimum peak appears at time t * diag,2 A maximum peak may appear at time t in the voltage profile g(t,V). * diag Moving forward and backward in time, t * diag,1 time and t * diag,2 This is because an inflection point occurs at time t * diagThe time t is the time when a symptom of core collapse of the electrode assembly JR is detected based on the swelling pressure profile f(t,p) or the differential swelling pressure profile f'(t,p). diag or t diag,1 Therefore, the method of monitoring both the swelling pressure and the minute voltage change over time is more effective in diagnosing the core collapse symptom of the electrode assembly JR in advance.

[0202] The voltage profile g(t,V) showing the voltage change over time can be replaced by a voltage profile h(SOC,V) showing the voltage change over time depending on the battery's State of Charge (SOC), where SOC is a variable indicating the state of charge and V is a variable indicating the voltage.

[0203] The cylindrical battery swelling pressure monitoring device 300 may further include a current measurement unit 308 to generate a voltage profile h(SOC, V). The current measurement unit 308 may include a current measurement circuit known in the art.

[0204] The control unit 303 measures the charging current or discharging current using the current measurement unit 308 while the battery is being charged or discharged, determines the state of charge of the battery using an ampere counting method, and accumulates and records the measured current together with a timestamp in the recording unit 304, thereby generating time-series data of the state of charge in the recording unit 304.

[0205] The control unit 303 can generate a voltage profile h(SOC, V) that indicates voltage changes according to the state of charge, using the time-series data of voltage and time-series data of the state of charge that are periodically generated in the recording unit 304.

[0206] FIG. 6h is a graph illustrating a voltage profile h(SOC, V) according to another embodiment of the present invention.

[0207] The control unit 303 may periodically generate a differential voltage profile g′(SOC, V) by differentiating the state of charge with respect to the voltage profile h(SOC, V).

[0208] As in the above-described embodiment, the control unit 303 can detect in advance the signs of core collapse of the electrode assembly JR by using the periodically generated differential voltage profile h'(SOC, V).

[0209] That is, the control unit 303 may refer to the time-series data of the swelling pressure generated in the recording unit 304, and when the conditions that the swelling pressure at the current time point is equal to or greater than a predetermined critical value and at least one peak is identified in the differential voltage profile h′(SOC, V) are satisfied, the control unit 303 may diagnose that there is a symptom of core collapse of the electrode assembly JR, and output the diagnosis result.

[0210] In this embodiment, signs of core collapse of the electrode assembly JR can be detected in advance more quickly than when signs of core collapse of the electrode assembly JR are detected using the swelling pressure profile f(t,p) or the differential swelling pressure profile f'(t,p). This is because when signs of core collapse of the electrode assembly JR occur, before a change in swelling pressure appears, the adhesion between the electrodes and the separator near the core deteriorates, reducing the effective area where an electrochemical reaction occurs. As a result, the battery voltage may slightly decrease and then increase according to the state of charge, as shown by the dotted line profile in Figure 6h.

[0211] Such minute voltage changes can be detected by monitoring whether a peak appears in the differential voltage profile h'(SOC, V). For example, as shown in Figure 6h, * diag If a minute voltage decrease pattern occurs in the voltage profile h(SOC, V) at time t, the differential voltage profile h'(SOC, V) * diag Moving forward and backward in time, t * diag,1 A minimum peak appears at time t * diag,2 A maximum peak may appear at time t in the voltage profile h(SOC, V). * diag Moving forward and backward in time, t* diag,1 time and t * diag,2 This is because an inflection point occurs at time t * diag The time t is the time when a symptom of core collapse of the electrode assembly JR is detected based on the swelling pressure profile f(t,p) or the differential swelling pressure profile f'(t,p). diag or t diag,1 Therefore, a method of monitoring both the swelling pressure and minute voltage changes according to the state of charge is more effective in pre-diagnosing signs of core collapse of the electrode assembly JR.

[0212] In yet another embodiment, the control unit 303 may visually output the diagnostic results of the above-described embodiments through the display unit 305. The display unit 305 may be provided in a device that receives power from a battery and may be a known display such as a liquid crystal display (LCD) or an organic light-emitting diode (OLED). The device may be an electric vehicle, and the display unit 305 may be an integrated display provided in the electric vehicle. However, the present invention is not limited by the type of device.

[0213] In yet another embodiment, the control unit 303 may transmit the diagnostic results of the above-described embodiments to another computer system 310 through the communication unit 306. The communication unit 306 may be a communication interface capable of transmitting and receiving data signals to and from an external device, and may be a communication modem. The communication modem may support wired or wireless communication. The computer system 310 may be a diagnostic device. The diagnostic device may be provided in a service center that can professionally perform battery testing and diagnosis.

[0214] The diagnosis result may include a warning message or a diagnosis request message. The warning message may include information notifying a user that a safety problem has occurred in the battery. The inspection request message may include a request for the user to perform a safety diagnosis of the battery. When the warning message or the diagnosis request message is provided, the user visits a service center that specializes in inspections of devices equipped with the battery, has the battery thoroughly inspected, and if collapse of the electrode assembly core is confirmed, replaces the battery.

[0215] The control unit 303 may read the time-series data of the swelling pressure from the recording unit 304 in accordance with the control command, and output the data through the display unit 305 or transmit the data to another computer system through the communication unit 306. The control command may be input from the battery diagnostic device through the communication unit 306. If the display unit 305 is a display including a touch sensor, the control command may be input directly through the display unit 305.

[0216] In one embodiment of the present invention, the control unit 303 may optionally include a processor, an application-specific integrated circuit (ASIC), other chipsets, logic circuits, registers, a communication modem, a data processing device, or the like, known in the art, to execute various control logics. Furthermore, when the control logic is embodied as software, the control unit 303 may be embodied as a collection of program modules. In this case, the program modules may be stored in memory and executed by the processor. The memory may be provided inside or outside the processor and may be connected to the processor by various well-known computer components. Furthermore, the memory may be included in the recording unit 304 according to one embodiment of the present invention. Furthermore, the memory is a general term for devices in which information is recorded, regardless of the type of device, and does not refer to a specific memory device.

[0217] At least one of the various control logics of the control unit 303 may be combined, and the combined control logic may be created as a computer-readable code system and recorded on a computer-readable recording medium. The type of the recording medium is not particularly limited as long as it is accessible by a processor included in a computer. For example, the recording medium may include at least one selected from the group consisting of ROM, RAM, register, CD-ROM, magnetic disk, hard disk, floppy disk, and optical data recording device. The code system may also be distributed and recorded on and executed by computers connected via a network. Functional programs, codes, and code segments for implementing the combined control logic may be easily construed by a programmer skilled in the art to which the present invention pertains.

[0218] In one embodiment of the present invention, the recording unit 304 may include at least one form of recording medium selected from the group consisting of flash memory, a hard disk, a solid state disk (SSD), a silicon disk drive (SDD), a multimedia microcard, random access memory (RAM), static RAM (SRAM), read only memory (ROM), electrically erasable programmable ROM (EEPROM), and programmable ROM (PROM).

[0219] The recording unit 304 may record data and programs required for the calculation operation by the control unit 303. The recording unit 304 may record data indicating the results of the calculation operation by the control unit 303. In particular, the control unit 303 may record data indicating the results of the calculation operation by the pressure sensor P sensor The time series data of the swelling pressure, the time series data of the battery voltage, the time series data of the battery charge / discharge current, and / or the time series data of the battery state of charge determined by processing the RF signal transmitted from the storage unit 304 may be accumulated and recorded in the recording unit 304.

[0220] In one embodiment of the present invention, the pressure sensor P sensor A plurality of cylindrical batteries including the above may be connected in series and / or in parallel to form a battery pack.

[0221] To save costs, pressure sensor P sensor It is also possible to include the battery pack in only some of the cylindrical batteries that make up the battery pack.

[0222] The cylindrical battery swelling pressure monitoring device 300 may be included in a battery management system that generally controls the charging and discharging of the battery pack.

[0223] The battery management system uses the swelling pressure monitoring device 300 to periodically monitor the change in swelling pressure over time, and optionally the change in voltage over time or the state of charge, for (a plurality of) cylindrical batteries including a pressure sensor among the cylindrical batteries included in the battery pack, to diagnose signs of core collapse of the electrode assembly in advance, and may output the diagnosis results through the display unit 305 or transmit them to another computer system through the communication unit 306.

[0224] In the above-described embodiments, components referred to as "units" may be embodied as electronic circuits. Those skilled in the art can easily design electronic circuits by recognizing the functions of the components. Furthermore, the components of the device should be understood as functionally separated elements, not physically separated elements. Therefore, each component may be selectively integrated with other components, or each component may be divided into subcomponents for efficient execution of control logic. However, it will be obvious to those skilled in the art that, even if components are integrated or divided, as long as the functional identity can be recognized, the integrated or divided components are also construed as being within the scope of the present invention.

[0225] Other features of the cylindrical battery according to an embodiment of the present invention will be described in detail below.

[0226] FIG. 7a is a plan view showing the structure of an electrode 40 included in an electrode assembly according to an embodiment of the present invention.

[0227] Referring to FIG. 7a, electrode 40 includes current collector 41 made of metal foil and active material layer 42. The metal foil may be made of a conductive metal, such as aluminum or copper, and is appropriately selected depending on the polarity of electrode 40. Active material layer 42 is formed on at least one surface of current collector 41. Active material layer 42 is formed along the winding direction (X-axis). Electrode 40 includes uncoated portion 43 at the end of the long side in the winding direction (X-axis). Uncoated portion 43 is a portion of current collector 41 that is not coated with active material. The region of current collector 41 on which active material layer 42 is formed may be referred to as the active material portion.

[0228] In electrode 40, the width of the active material portion in the direction of the short sides of current collector 41 may be 50 mm to 120 mm, and the length of the active material portion in the direction of the long sides of current collector 41 may be 3 m to 5 m. Therefore, the ratio of the short sides to the long sides of the active material portion may be 1.0% to 4.0%.

[0229] Preferably, in electrode 40, the width of the active material portion in the direction of the short sides of current collector 41 may be 60 mm to 70 mm, and the length of the active material portion in the direction of the long sides of current collector 41 may be 3 m to 5 m. Therefore, the ratio of the short sides to the long sides of the active material portion may be 1.2% to 2.3%.

[0230] The ratio of the short side to the long side of the active material portion is significantly smaller than the 6% to 11% ratio of the long side to the short side of the active material portion of electrodes used in cylindrical batteries having 1865 or 2170 form factors.

[0231] Preferably, an insulating coating layer 44 may be formed at the boundary between the active material layer 42 and the uncoated portion 43. The insulating coating layer 44 is formed so that at least a portion thereof overlaps the boundary between the active material layer 42 and the uncoated portion 43. The insulating coating layer 44 prevents short-circuiting between two electrodes of opposite polarity that face each other via a separator. The insulating coating layer 44 may cover the boundary between the active material layer 42 and the uncoated portion 43 with a width of 0.3 mm to 5 mm.

[0232] The uncoated portion 43 includes a core-side uncoated portion B1 adjacent to the core side of the electrode assembly, an outer-periphery-side uncoated portion B3 adjacent to the outer periphery side of the electrode assembly, and an intermediate uncoated portion B2 interposed between the core-side uncoated portion B1 and the outer-periphery-side uncoated portion B3.

[0233] When the electrode 40 is wound into a jelly roll-type electrode assembly, the core-side uncoated area B1, the outer-periphery-side uncoated area B3, and the middle uncoated area B2 can be defined as the uncoated area adjacent to the core side, the uncoated area adjacent to the outer periphery, and the uncoated area excluding these, respectively.

[0234] Hereinafter, the core-side uncoated portion B1, the outer-periphery-side uncoated portion B3, and the middle uncoated portion B2 will be referred to as the first portion, the second portion, and the third portion, respectively.

[0235] The height of the non-coating portion 43 is not constant but varies relatively in the winding direction (X-axis). That is, the height (length in the Y-axis direction) of the second portion B3 is equal to or greater than 0 and is relatively shorter than the first portion B1 and the third portion B2. In the winding direction (X-axis), the length of the third portion B2 is longer than the first portion B1 and the second portion B3.

[0236] FIG. 7b is a plan view showing the structure of an electrode 45 according to another embodiment of the present invention.

[0237] Referring to FIG. 7b, the electrode 45 is substantially the same as the electrode 40 described above in other respects, except that the height of the second portion B3 gradually decreases toward the outer periphery.

[0238] In one variant, the second portion B3 can be deformed in the shape of a staircase (see dotted lines) with a stepwise decrease in height.

[0239] FIG. 7c is a plan view showing the structure of an electrode 50 according to yet another embodiment of the present invention.

[0240] 7c, the electrode 50 has a first portion B1 and a second portion B3 each having a height greater than or equal to 0 and lower than the third portion B2. The heights of the first portion B1 and the second portion B3 may be the same or different.

[0241] Preferably, the height of the third portion B2 may be in a step shape that increases stepwise from the core side toward the outer periphery side.

[0242] Patterns 1 to 7 divide the third portion B2 around the positions where the height of the uncoated portion 43 changes. Preferably, the number of patterns and the height (length in the Y-axis direction) and width (length in the X-axis direction) of each pattern can be adjusted to maximize stress distribution during the bending process of the uncoated portion 43. The stress distribution is intended to prevent the uncoated portion 43 from breaking when it is bent toward the core of the electrode assembly.

[0243] The width dB1 of the first portion B1 is designed so that the core of the electrode assembly is not blocked when the pattern of the third portion B2 is bent toward the core. The core refers to the cavity present at the center of the winding of the electrode assembly.

[0244] For example, the width dB1 of the first portion B1 may increase in proportion to the bending length of the pattern 1. The bending length corresponds to the height of the pattern based on the bending point of the pattern.

[0245] Preferably, the width dB1 of the first portion B1 can be set so that the width in the radial direction of the wound turn formed by the first portion B1 is equal to or greater than the bending length of the pattern 1.

[0246] In a specific example, when the electrode 50 is used to manufacture an electrode assembly for a cylindrical battery with a form factor of 4680, the width dB1 of the first portion B1 may be set to 180 mm to 350 mm depending on the diameter of the core of the electrode assembly and the bending length of pattern 1.

[0247] In another example, the height of the third portion B2 may have a step shape that increases and then decreases from the core side toward the outer periphery side.

[0248] In yet another example, the second portion B3 can be modified to have the structure of the electrode 45 of Figure 7b.

[0249] In yet another example, a pattern structure applied to the third portion B2 may be extended to the second portion B3 (see dotted line).

[0250] FIG. 7d is a plan view showing the structure of an electrode 60 according to yet another embodiment of the present invention.

[0251] 7d, the height of the first portion B1 and the second portion B3 in the winding axis (Y-axis) direction of the electrode 60 is equal to or greater than 0 and is relatively lower than the third portion B2. The height of the first portion B1 and the height of the second portion B3 in the winding axis (Y-axis) direction may be the same or different.

[0252] Preferably, at least a portion of the third portion B2 may include a plurality of segmented pieces 61. The height of the plurality of segmented pieces 61 may increase stepwise from the core side to the outer periphery side. The plurality of segmented pieces 61 may have a geometric shape whose width decreases from bottom to top. Preferably, the geometric shape is a trapezoid. The geometric shape may be variously modified, such as a rectangle, a parallelogram, a semicircle, or a semi-ellipse.

[0253] The segment 61 may be laser notched or may be formed by known metal foil cutting processes such as ultrasonic cutting or punching.

[0254] In one embodiment, the plurality of segment pieces 61 may be arranged in a plurality of segment piece groups from the core side toward the outer periphery side. At least one of the width, height, and spacing pitch of the segment pieces belonging to the same segment piece group may be substantially the same. Preferably, the width, height, and spacing pitch of the segment pieces belonging to the same segment piece group may be the same.

[0255] When the uncoated portion 43 of the electrode 60 has a segment structure, the electrode 60 may include a segment-omitted section 64 in which some of the multiple segments are regularly or irregularly omitted, as shown in Figure 7e.

[0256] Preferably, there may be a plurality of segment-omitted sections 64. As one example, the width of the segment-omitted sections 64 may be constant from the core side to the outer periphery side. As another example, the width of the segment-omitted sections 64 may increase or decrease regularly or irregularly from the core side to the outer periphery side. Preferably, the height of the uncoated portion present in the segment-omitted sections 64 may correspond to the height of the first portion B1 and / or the second portion B3.

[0257] The number of the segment segments 61 present between the segment-omitted sections 64 may be at least one. The electrode 60 may include uncoated sections in which the number of segment segments 61 present between the segment-omitted sections 64 increases from the core toward the outer periphery, as shown in FIG. 7e.

[0258] Preferably, the width of the segment omission section 64 can be set so that when the electrode 60 is wound, the segment located on each winding turn is located within a predetermined independent area 66 based on the center C of the core of the electrode assembly 65, as shown in Figure 7f.

[0259] That is, when the electrode assembly 65 is viewed in the winding axis direction, the plurality of segments 61 may be located within a plurality of independent regions 66 based on the center of the core. The number of independent regions 66 may vary, such as two, three, four, or five.

[0260] Preferably, the independent regions 66 may be fan-shaped. In this case, the angles between the independent regions 66 may be substantially uniform. Furthermore, the circumferential angle δ of the independent regions 66 may be 20° or more, optionally 25° or more, optionally 30° or more, optionally 35° or more, or optionally 40° or more.

[0261] In alternative embodiments, the independent regions 66 may have the form of a geometric figure such as a square, rectangle, parallelogram, trapezoid, or the like.

[0262] According to yet another aspect of the present invention, after the electrode 60 is wound into an electrode assembly, the exposed portions on the upper and lower sides of the electrode assembly may overlap in multiple ways along the radial direction of the electrode assembly to form a folded surface region.

[0263] 8 is a schematic diagram showing a cross section of a folded surface region F formed by bending a divided piece 61 toward a core C of an electrode assembly 80 according to an embodiment of the present invention. In FIG. 8, the cross section of the folded surface region F is shown only on the left side based on the winding axis of the electrode assembly 80. The folded surface region F may be formed on both the top and bottom of the electrode assembly 80.

[0264] Referring to FIG. 8, the folded surface region F has a structure in which the split segments 61 are stacked in multiple layers in the winding axis direction. The stacking direction is the winding axis direction (Y axis). Section 1 is a split segment-free section (first part B1) where there are no split segments, and sections 2 and 3 are sections where winding turns including split segments are located. Section 2 is a height-variable section where the height of the split segments 61 varies, and section 3 is a height-uniform section where the split segment height is maintained uniform up to the outer periphery of the electrode assembly. As will be described later, the radial lengths of sections 2 and 3 may vary. Meanwhile, the uncoated portion (second part B3) included in at least one winding turn, including the outermost winding turn, may not include a split segment structure.

[0265] Preferably, by adjusting the height, width and spacing pitch of the segment 61 according to the radius of the winding turn containing the segment 61, the number of stacked segments 61 at each position of the folded surface area F can be designed to a minimum of 10 or more in accordance with the required welding strength of the current collector.

[0266] The electrode structure of the above-described embodiment (variant) may be applied to at least one of the first electrode and the second electrode having different polarities included in the jelly roll-type electrode assembly. Furthermore, when the electrode structure of the embodiment (variant) is applied to one of the first electrode and the second electrode, a conventional electrode structure may be applied to the other. Furthermore, the electrode structures applied to the first electrode and the second electrode may not be the same, but may be different.

[0267] As an example, when the first electrode and the second electrode are positive and negative electrodes, respectively, any one of the embodiments (variants) may be applied to the first electrode, and a conventional electrode structure (see FIG. 1) may be applied to the second electrode.

[0268] As another example, when the first electrode and the second electrode are positive and negative electrodes, respectively, one of the embodiments (variants) may be selectively applied to the first electrode, and another of the embodiments (variants) may be selectively applied to the second electrode.

[0269] In one embodiment of the present invention, the positive electrode active material coated on the positive electrode and the negative electrode active material coated on the negative electrode may be any active material known in the art without limitation.

[0270] As an example, the positive electrode active material has the general chemical formula A[A x M y ]O 2+z (A includes at least one element of Li, Na, and K; M includes at least one element selected from Ni, Co, Mn, Ca, Mg, Al, Ti, Si, Fe, Mo, V, Zr, Zn, Cu, Al, Mo, Sc, Zr, Ru, and Cr; x≧0, 1≦x+y≦2, −0.1≦z≦2; and the stoichiometric coefficients x, y, and z are selected to maintain electroneutrality of the compound).

[0271] As another example, the positive electrode active material is an alkali metal compound xLiM disclosed in U.S. Patent No. 6,677,082, U.S. Patent No. 6,680,143, etc. 1 O2-(1-x)Li2M 2 O3 (M 1 contains at least one element having an average oxidation state of 3; M 2 contains at least one element having an average oxidation state of 4; 0 ≦ x ≦ 1).

[0272] As yet another example, the positive electrode active material has the general chemical formula Li a M 1 x Fe 1-x M 2 y P 1-y M 3 z O 4-z (M 1 contains at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, and Al; M 2 contains at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, Al, As, Sb, Si, Ge, V, and S; M 3 contains a halogen group element selectively containing F; 0 < a ≦ 2, 0 ≦ x ≦ 1, 0 ≦ y < 1, 0 ≦ z < 1; the stoichiometric coefficients a, x, y, and z are selected so that the compound maintains electrical neutrality), or Li3M2(PO4)3 [M contains at least one element selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Al, Mg, and Al].

[0273] Preferably, the positive electrode active material may include primary particles and / or secondary particles formed by aggregation of primary particles.

[0274] For example, the negative electrode active material may be a carbon material, lithium metal or a lithium metal compound, silicon or a silicon compound, or tin or a tin compound. Metal oxides such as TiO2 and SnO2, which have a potential of less than 2 V, may also be used as the negative electrode active material. The carbon material may be either low-crystalline carbon or high-crystalline carbon.

[0275] The separator may be a porous polymer film, for example, a porous polymer film made of a polyolefin polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, an ethylene / methacrylate copolymer, etc., either alone or in a laminate. Alternatively, the separator may be a conventional porous nonwoven fabric, for example, a nonwoven fabric made of high-melting-point glass fiber, polyethylene terephthalate fiber, etc.

[0276] At least one surface of the separator may include a coating layer of inorganic particles. Alternatively, the separator itself may be made of a coating layer of inorganic particles. The particles constituting the coating layer may have a structure in which they are bound with a binder so that there is interstitial volume between adjacent particles.

[0277] The inorganic particles may be made of an inorganic material having a dielectric constant of 5 or more. Non-limiting examples of the inorganic particles include Pb(Zr,Ti)O3 (PZT), Pb 1-x La x ZR 1-y Ti y O3(PLZT), PB(Mg3Nb 2 / 3 )O3-PbTiO3 (PMN-PT), BaTiO3, hafnia (HfO2), SrTiO3, TiO2, Al2O3, ZrO2, SnO2, CeO2, MgO, CaO, ZnO, and Y2O3.

[0278] In one embodiment of the present invention, the cylindrical battery may be a cylindrical battery having a form factor ratio (defined as the diameter divided by the height of the cylindrical battery, i.e., the ratio of height (H) to diameter (Φ)) of greater than about 0.4, where form factor refers to a value indicating the diameter and height of the cylindrical battery.

[0279] Preferably, the diameter of the cylindrical battery may be 40 mm to 50 mm, and the height may be 60 mm to 130 mm. The form factor of the cylindrical battery according to one embodiment may be, for example, 46110, 4875, 48110, 4880, or 4680. In the number indicating the form factor, the first two digits indicate the diameter of the battery, and the remaining digits indicate the height of the battery. The number of winding turns of the electrode assembly may be 50 to 60 turns.

[0280] FIG. 9 is a cross-sectional view of a cylindrical battery 190 according to an embodiment of the present invention taken along the Y-axis direction.

[0281] Referring to FIG. 9, a cylindrical battery 190 according to an embodiment of the present invention includes an electrode assembly 110 including a first electrode, a separator, and a second electrode, a battery housing 142 that houses the electrode assembly 110, and a seal 143 that seals the open end of the battery housing 142.

[0282] The battery housing 142 is a cylindrical container with an opening at the top. The battery housing 142 is made of a conductive metal material such as aluminum, steel, or stainless steel. A nickel coating layer may be formed on the surface of the battery housing 142. The battery housing 142 accommodates the electrode assembly 110 in the internal space through the opening at the top, along with the electrolyte.

[0283] As shown in FIG. 2, the electrode assembly 110 may be manufactured by stacking a lower separator, a first electrode, an upper separator, and a second electrode in sequence at least once, and winding the stack around a winding shaft C.

[0284] The first electrode and the second electrode have opposite polarities. That is, one has a positive polarity and the other has a negative polarity. At least one of the first electrode and the second electrode may have an electrode structure according to the above-described embodiment (variant). The other of the first electrode and the second electrode may have a conventional electrode structure or an electrode structure according to the embodiment (variant). The number of electrode pairs included in the electrode assembly 110 is not limited to one, but may be two or more.

[0285] Between the outer circumferential surface of the electrode assembly 110 and the inner circumferential surface of the battery housing 142, a pressure sensor P sensor A pressure sensor P sensor The detailed configuration and installation position of the pressure sensor P have already been described above. sensor The electrode assembly 110 may sense the swelling pressure that the outer circumferential surface of the electrode assembly 110 applies to the inner circumferential surface of the battery housing 142, and transmit the pressure sensing signal to an external swelling pressure monitoring device (300 in FIG. 6e) via wireless communication.

[0286] A first uncoated portion 146a of the first electrode and a second uncoated portion 146b of the second electrode protrude from the top and bottom, respectively, of the electrode assembly 110. The first uncoated portion 146a and the second uncoated portion 146b may be bent toward the core of the electrode assembly 110 to form a bent surface region F. The second portion B3 of the first electrode is spaced a predetermined distance from the inner circumferential surface of the battery housing 142, particularly the beading portion 147. Therefore, the second portion B3 of the first electrode does not contact the battery housing 142, which is electrically connected to the second electrode, thereby preventing an internal short circuit.

[0287] The second uncoated portion 146b of the second electrode may have substantially the same structure as the first uncoated portion 146a. In another variant, the second uncoated portion 146b may selectively have the structure of the uncoated portion of the electrode according to the embodiment (variant).

[0288] The sealing body 143 may include a plate-shaped cap 143a, an insulating sealing gasket 143b that provides airtightness between the cap 143a and the battery housing 142, and a connecting plate 143c that is electrically and mechanically connected to the cap 143a.

[0289] The cap 143a is a part made of a conductive metal material and covers the upper opening of the battery housing 142. The cap 143a is electrically connected to the first uncoated portion 146a of the first electrode and is electrically insulated from the battery housing 142 via a sealing gasket 143b. Therefore, the cap 143a can function as a first electrode terminal (e.g., a positive electrode) of the cylindrical battery 190.

[0290] The cap 143a is placed on a beading portion 147 formed on the battery housing 142 and fixed by a crimping portion 148. A sealing gasket 143b may be interposed between the cap 143a and the crimping portion 148 to ensure airtightness of the battery housing 142 and to provide electrical insulation between the battery housing 142 and the cap 143a. The cap 143a may have a protrusion 143d formed to protrude upward from the center thereof.

[0291] The battery housing 142 is electrically connected to the second uncoated portion 146b of the second electrode. Therefore, the battery housing 142 has the same polarity as the second electrode. If the second electrode has a negative polarity, the battery housing 142 also has a negative polarity.

[0292] The battery housing 142 has a beading portion 147 and a crimping portion 148 at its upper end. The beading portion 147 is formed by pressing in around the outer periphery of the battery housing 142. The beading portion 147 prevents the electrode assembly 110 housed inside the battery housing 142 from slipping out of the upper opening of the battery housing 142, and can also function as a support on which the sealing body 143 is placed.

[0293] The inner circumferential surface of the beading portion 147 is spaced a predetermined distance from the second portion B3 of the first electrode. More specifically, the lower end of the inner circumferential surface of the beading portion 147 is spaced a predetermined distance from the second portion B3 of the first electrode. In addition, because the second portion B3 has a low height, it is not substantially affected when the battery housing 142 is pressed from the outside to form the beading portion 147. Therefore, the second portion B3 is not compressed by other components such as the beading portion 147, which prevents partial deformation of the electrode assembly 110 and internal short circuits in the cylindrical battery 190.

[0294] Preferably, the relationship "D1≦D2" can be satisfied, where D1 is the pressing depth of the beading portion 147 and D2 is the radial length from the inner circumferential surface of the battery housing 142 to the boundary between the second portion B3 and the third portion B2. In this case, damage to the second portion B3 is substantially prevented when the battery housing 142 is pressed to form the beading portion 147.

[0295] The crimping portion 148 is formed on the upper portion of the beading portion 147. The crimping portion 148 is extended and bent to enclose the outer circumferential surface of the cap 143a disposed on the beading portion 147 and a part of the upper surface of the cap 143a.

[0296] The cylindrical battery 190 may further include a first current collector 144 and / or a second current collector 145 and / or an insulator 146 .

[0297] The first current collector 144 is coupled to the upper part of the electrode assembly 110. The first current collector 144 is made of a conductive metal material such as aluminum, copper, steel, nickel, etc., and is electrically connected to the first uncoated portion 146a of the first electrode. The electrical connection may be made by welding. A lead 149 may be connected to the first current collector 144. The lead 149 may extend above the electrode assembly 110 and be coupled to the connection plate 143c, or may be directly coupled to the lower surface of the cap 143a. The lead 149 may be coupled to other components by welding.

[0298] Preferably, the first current collector 144 may be integrally formed with the lead 149. In this case, the lead 149 may have a long plate shape extending outward from near the center of the first current collector 144.

[0299] The first current collector 144 is bonded to the folded surface region F of the first uncoated portion 146a. The bonding between the folded surface region F of the first uncoated portion 146a and the first current collector 144 may be performed by, for example, laser welding. Laser welding may be performed by partially melting the base material of the first current collector 144. Laser welding may be replaced by resistance welding, ultrasonic welding, spot welding, etc.

[0300] A second current collector 145 may be coupled to the bottom surface of the electrode assembly 110. One surface of the second current collector 145 may be coupled to the folded surface region F of the second uncoated portion 146b by welding, and the other surface may be coupled to the inner bottom surface of the battery housing 142 by welding. The coupling structure between the second current collector 145 and the second uncoated portion 146b may be substantially the same as the coupling structure between the first current collector 144 and the first uncoated portion 146a.

[0301] When the first current collector 144 and the second current collector 145 are welded to the bent surface regions F of the first uncoated portion 146a and the second uncoated portion 146b, respectively, it is possible to prevent the electrodes from rotating when the electrode assembly 110 swells. This effect is also achieved in the following embodiments.

[0302] The uncoated portions 146a, 146b are not limited to the structure shown in the figure, and therefore may selectively have the structure of an uncoated portion of an electrode according to an embodiment (variant) as well as the structure of a conventional uncoated portion.

[0303] The insulator 146 can cover the first current collector 144. By covering the first current collector 144 on the upper surface of the first current collector 144, the insulator 146 can prevent direct contact between the first current collector 144 and the inner circumferential surface of the battery housing 142.

[0304] The insulator 146 has a lead hole 151 through which the lead 149 extending upward from the first current collector 144 is drawn out. The lead 149 is drawn out upward through the lead hole 151 and is coupled to the lower surface of the connecting plate 143c or the lower surface of the cap 143a.

[0305] The peripheral region of the insulator 146 may be interposed between the first current collector 144 and the beading portion 147 to fix the combination of the electrode assembly 110 and the first current collector 144. This limits movement of the combination of the electrode assembly 110 and the first current collector 144 in the winding axis direction (Y-axis direction) of the cylindrical battery 190, thereby improving the assembly stability of the cylindrical battery 190.

[0306] The insulator 146 may be made of an insulating polymer resin. For example, the insulator 146 may be made of polyethylene, polypropylene, polyimide, or polybutylene terephthalate.

[0307] The battery housing 142 may further include a vent 152 formed on its bottom surface. The vent 152 corresponds to a region on the bottom surface of the battery housing 142 that is thinner than the surrounding region. The vent 152 is structurally weaker than the surrounding region. Therefore, if an abnormality occurs in the cylindrical battery 190 and the internal pressure increases above a certain level, the vent 152 may burst, causing gas generated inside the battery housing 142 to be released to the outside.

[0308] The vents 152 may be formed in a continuous or discontinuous circular pattern on the underside of the battery housing 142. Alternatively, the vents 152 may be formed in a linear pattern or other patterns.

[0309] FIG. 10 is a cross-sectional view of a cylindrical battery 200 according to another embodiment of the present invention taken along the Y axis.

[0310] Referring to FIG. 10, a cylindrical battery 200 is different from the cylindrical battery 190 shown in FIG. 9 in that the structure of the electrode assembly is substantially the same, but other structures except for the electrode assembly have been changed.

[0311] Cylindrical battery 200 is a pressure sensor P sensor Includes pressure sensor P sensor The pressure sensor P may be interposed between the outer circumferential surface of the electrode assembly 110 and the inner circumferential surface of the battery housing 171. sensor The detailed configuration and installation position of the pressure sensor P have already been described above. sensor The electrode assembly 110 may sense the swelling pressure that the outer circumferential surface of the electrode assembly 110 applies to the inner circumferential surface of the battery housing 171, and transmit the pressure sensing signal to an external swelling pressure monitoring device (300 in FIG. 6e) via wireless communication.

[0312] The cylindrical battery 200 includes a battery housing 171 through which a terminal 172 is inserted. The terminal 172 is attached through a through-hole formed in the closed surface (top surface in the drawing) of the battery housing 171. The terminal 172 is riveted into the through-hole of the battery housing 171 with an insulating gasket 173 made of an insulating material interposed therebetween. The terminal 172 is exposed outward in the direction opposite to the direction of gravity.

[0313] The terminal 172 may be a rivet terminal including a terminal exposure portion 172a and a terminal insertion portion 172b. The terminal exposure portion 172a is exposed to the outside of the closed surface of the battery housing 171. The terminal exposure portion 172a may be located approximately at the center of the closed surface of the battery housing 171. The maximum diameter of the terminal exposure portion 172a may be larger than the maximum diameter of the through-hole formed in the battery housing 171. The terminal insertion portion 172b may penetrate approximately the center of the closed surface of the battery housing 171 to be electrically connected to the first uncoated portion 146a of the first electrode. The bottom edge of the terminal insertion portion 172b may be riveted onto the inner surface of the battery housing 171. That is, the bottom edge of the terminal insertion portion 172b may be bent toward the inner surface of the battery housing 171. A flat portion 172c may be included on the inside of the bottom edge of the terminal insertion portion 172b. The maximum diameter of the bottom of the riveted terminal insert 172b can be even larger than the maximum diameter of the through hole in the battery housing 171.

[0314] The flat portion 172c of the terminal insertion portion 172b may be welded to the center of the first current collector 144 connected to the first uncoated portion 146a of the first electrode. Laser welding is a preferred welding method, but other welding methods such as ultrasonic welding may be used instead.

[0315] An insulator 174 made of an insulating material may be interposed between the first current collector 144 and the inner surface of the battery housing 171. The insulator 174 covers the upper portion of the first current collector 144 and the upper peripheral edge portion of the electrode assembly 110. This prevents a short circuit from occurring due to contact between the first uncoated portion 146a of the electrode assembly 110 having opposite polarities and the inner surface of the battery housing 171.

[0316] The thickness of the insulator 174 corresponds to or is slightly larger than the distance between the top surface of the first current collector 144 and the inner surface of the closed portion of the battery housing 171. Thus, the insulator 174 can contact the top surface of the first current collector 144 and the inner surface of the closed portion of the battery housing 171.

[0317] The terminal insertion portion 172b of the terminal 172 may be welded to the first current collector 144 through a through-hole in the insulator 174. The diameter of the through-hole formed in the insulator 174 may be larger than the diameter of the rivet portion at the bottom of the terminal insertion portion 172b. Preferably, the through-hole may expose the bottom of the terminal insertion portion 172b and the insulating gasket 173.

[0318] The insulating gasket 173 is interposed between the battery housing 171 and the terminal 172 to prevent electrical contact between the battery housing 171 and the terminal 172, which have opposite polarities. This allows the upper surface of the battery housing 171, which has a substantially flat shape, to function as a second electrode terminal (e.g., a negative electrode) of the cylindrical battery 200.

[0319] The insulating gasket 173 includes a gasket exposing portion 173a and a gasket inserting portion 173b. The gasket exposing portion 173a is interposed between the terminal exposing portion 172a of the terminal 172 and the battery housing 171. The gasket inserting portion 173b is interposed between the terminal inserting portion 172b of the terminal 172 and the battery housing 171. The gasket inserting portion 173b may be deformed when the terminal inserting portion 172b is riveted, thereby being tightly attached to the inner surface of the battery housing 171. The insulating gasket 173 may be made of, for example, an insulating polymer resin.

[0320] The gasket exposing portion 173a of the insulating gasket 173 may extend to cover the outer peripheral surface of the terminal exposing portion 172a of the terminal 172. When the insulating gasket 173 covers the outer peripheral surface of the terminal 172, it is possible to prevent a short circuit from occurring during the process of connecting an electrical connection part such as a bus bar to the upper surface of the battery housing 171 and / or the terminal 172. Although not shown, the gasket exposing portion 173a may extend to cover not only the outer peripheral surface of the terminal exposing portion 172a but also a portion of the upper surface.

[0321] When insulating gasket 173 is made of a polymer resin, insulating gasket 173 can be joined to battery housing 171 and terminal 172 by heat sealing. In this case, the airtightness is enhanced at the joining interface between insulating gasket 173 and terminal 172 and at the joining interface between insulating gasket 173 and battery housing 171. On the other hand, when gasket exposed portion 173a of insulating gasket 173 has a configuration that extends to the upper surface of terminal exposed portion 172a, terminal 172 may be joined integrally with insulating gasket 173 by insert injection molding.

[0322] On the upper surface of the battery housing 171, a region 175 other than the region occupied by the terminal 172 and the insulating gasket 173 corresponds to a second electrode terminal having a polarity opposite to that of the terminal 172.

[0323] The second current collector 176 is coupled to the lower part of the electrode assembly 110. The second current collector 176 is made of a conductive metal material such as aluminum, steel, copper, or nickel, and is electrically connected to the second uncoated portion 146b of the second electrode.

[0324] Preferably, the second current collector 176 is electrically connected to the battery housing 171. Therefore, the second current collector 176 may be fixed with at least a portion of its peripheral edge interposed between the inner surface of the battery housing 171 and the sealing gasket 178b. As an example, at least a portion of the peripheral edge of the second current collector 176 may be fixed to the beading portion 180 by welding while being supported on the lower end surface of the beading portion 180 formed at the lower end of the battery housing 171. In a modified example, at least a portion of the peripheral edge of the second current collector 176 may be directly welded to the inner circumferential surface of the battery housing 171.

[0325] Preferably, the second current collector 176 and the folded surface region F of the second uncoated portion 146b may be joined by welding, for example, laser welding. In addition, the welded portion between the second current collector 176 and the second uncoated portion 146b may be spaced a predetermined distance from the inner circumferential surface of the beading portion 180 toward the core C.

[0326] The sealing body 178, which seals the lower open end of the battery housing 171, includes a plate-shaped cap 178a and a sealing gasket 178b. The sealing gasket 178b electrically isolates the cap 178a from the battery housing 171. The crimping portion 181 secures the periphery of the cap 178a and the sealing gasket 178b together. The cap 178a is provided with a vent portion 179. The configuration of the vent portion 179 is substantially the same as in the above-described embodiment (variant). The lower surface of the cap 178a may be located above the lower end of the crimping portion 181. In this case, a space is formed below the cap 178a, allowing for smooth venting. This is particularly useful when the cylindrical battery 200 is installed with the crimping portion 181 facing the direction of gravity.

[0327] Preferably, cap 178a is made of a conductive metal material. However, cap 178a does not have electrical polarity because sealing gasket 178b is interposed between cap 178a and battery housing 171. Sealing body 178 seals the open end of the lower part of battery housing 171 and primarily functions to release gas when the internal pressure of battery 200 exceeds a critical value.

[0328] Preferably, the terminal 172 electrically connected to the first uncoated portion 146a of the first electrode is used as the first electrode terminal. Furthermore, a portion 175 of the upper surface of the battery housing 171, excluding the terminal 172, electrically connected to the second uncoated portion 146b of the second electrode via the second current collector 176 is used as the second electrode terminal having the opposite polarity to the first electrode terminal. When two electrode terminals are located on the upper portion of the cylindrical battery 200, electrical connection components such as bus bars can be disposed on only one side of the cylindrical battery 200. This simplifies the battery pack structure and improves energy density. Furthermore, the portion 175 used as the second electrode terminal has a substantially flat shape, ensuring a sufficient connection area for connecting electrical connection components such as bus bars. This allows the cylindrical battery 200 to reduce resistance at the connection points of the electrical connection components to a desirable level.

[0329] The cylindrical battery 200 according to an embodiment of the present invention has the advantage that electrical connections can be made at the top.

[0330] FIG. 11 is a top view showing a state in which a plurality of cylindrical batteries 200 are electrically connected according to an embodiment of the present invention, and FIG. 12 is a partially enlarged view of FIG.

[0331] 11 and 12, a plurality of cylindrical batteries 200 may be connected in series and parallel at the top of the cylindrical batteries 200 using bus bars 210. The number of cylindrical batteries 200 may be increased or decreased depending on the capacity of the battery pack.

[0332] In each cylindrical battery 200, the terminal 172 may have a positive polarity, and the flat surface 171a around the terminal 172 of the battery housing 171 may have a negative polarity. Of course, the opposite is also possible.

[0333] Preferably, the cylindrical batteries 200 may be arranged in a plurality of rows and columns. In the drawings, columns are in the vertical direction, and rows are in the horizontal direction. To maximize space efficiency, the cylindrical batteries 200 may be arranged in the closest packing structure. The closest packing structure is formed when an equilateral triangle is drawn when the centers of the terminals 172 exposed on the outside of the battery housings 171 are connected to each other. Preferably, the bus bars 210 connect the cylindrical batteries 200 arranged in the same column in parallel with each other, and connect the cylindrical batteries 200 arranged in two adjacent columns in series with each other.

[0334] Preferably, the bus bar 210 may include a body portion 211, a plurality of first bus bar terminals 212, and a plurality of second bus bar terminals 213 for series and parallel connection.

[0335] The body portion 211 may extend along the row of cylindrical batteries 200 between adjacent terminals 172. Alternatively, the body portion 211 may extend along the row of cylindrical batteries 200 but may be bent regularly, such as in a zigzag shape.

[0336] The plurality of first bus bar terminals 212 may extend from one side of the body portion 211 and be electrically coupled to the terminals 172 of the cylindrical battery 200 located on the one side. The electrical coupling between the first bus bar terminals 212 and the terminals 172 may be performed by laser welding, ultrasonic welding, or the like.

[0337] A plurality of second bus bar terminals 213 may extend from the other side of the body portion 211 and be electrically connected to the flat surface 171a around the terminals 172 located on the other side. The electrical connection between the second bus bar terminals 213 and the flat surface 171a may be performed by laser welding, ultrasonic welding, or the like.

[0338] Preferably, the body portion 211, the plurality of first bus bar terminals 212, and the plurality of second bus bar terminals 213 may be formed from a single conductive metal plate. The metal plate may be, for example, an aluminum plate or a copper plate, but the present invention is not limited thereto. Alternatively, the body portion 211, the plurality of first bus bar terminals 212, and the second bus bar terminals 213 may be manufactured as separate pieces and then joined together by welding or the like.

[0339] The cylindrical battery 200 according to the embodiment of the present invention has a structure in which resistance is minimized by expanding the welding area through the bent surface area F, multiple current paths using the second current collector 176, and minimizing the length of the current paths. The AC resistance of the cylindrical battery 200 measured by a resistance meter between the positive and negative electrodes, i.e., between the terminal 172 and the surrounding flat surface 171a, may be 0.5 mΩ to 4 mΩ, and preferably 1 mΩ to 4 mΩ, which is suitable for fast charging.

[0340] In the cylindrical battery 200 according to one embodiment of the present invention, the terminal 172 having a positive polarity and the flat surface 171a having a negative polarity are positioned in the same direction, so that electrical connection between the cylindrical batteries 200 can be easily achieved using the bus bar 210.

[0341] In addition, since the terminal 172 of the cylindrical battery 200 and the surrounding flat surface 171a have a large area, the connection area of ​​the bus bar 210 can be sufficiently secured, thereby sufficiently reducing the resistance of the battery pack including the cylindrical battery 200.

[0342] In addition, since electrical wiring can be performed on the top of the cylindrical battery 200, the energy density per unit volume of the battery module / pack can be maximized.

[0343] The cylindrical batteries according to the above-described embodiments (variations) are used to manufacture battery packs.

[0344] FIG. 13 is a diagram schematically illustrating the configuration of a battery pack according to an embodiment of the present invention.

[0345] 13, a battery pack 400 according to one embodiment of the present invention includes an assembly of electrically connected cylindrical batteries 401 and a pack housing 402 that accommodates the assembly. The cylindrical battery 401 may be any one of the batteries according to the above-described embodiments (variants). For convenience of illustration, components such as bus bars for electrical connection of the cylindrical battery 401, a cooling unit, and external terminals are not shown.

[0346] The plurality of cylindrical batteries 401 are connected to a pressure sensor P according to an embodiment of the present invention. sensor Optionally, only a portion of the plurality of cylindrical batteries 401 may include a pressure sensor P according to an embodiment of the present invention. sensor may include:

[0347] The battery pack 400 may be operatively coupled to a battery management system (BMS) that controls charging and discharging of the battery pack 400, calculates and monitors operating parameters such as a state of charge (SOC), a state of health (SOH), and available power, and can take protective action such as overcurrent / overcharge / overdischarge shutdown.

[0348] A battery management system (BMS) may include a swelling pressure monitoring device 300 according to an embodiment of the present invention. The swelling pressure monitoring device 300 includes a pressure sensor P sensorThe pressure sensing signal is collected via wireless communication from a cylindrical battery including the electrode assembly, and time series data of the swelling pressure applied by the outer surface of the electrode assembly to the inner surface of the battery housing is generated. The time series data of the swelling pressure and, optionally, the time series data of the voltage are used to diagnose signs of core collapse of the electrode assembly, and the diagnosis result may be visually output through a display unit or transmitted to another computer system through a communication unit.

[0349] The battery pack 400 is mounted on a vehicle. The vehicle may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle may be a four-wheeled vehicle or a two-wheeled vehicle.

[0350] FIG. 14 is a diagram illustrating a vehicle including the battery pack 400 of FIG.

[0351] 14, an automobile V according to an embodiment of the present invention includes a battery pack 400 according to an embodiment of the present invention. The automobile V operates by receiving power from the battery pack 400 according to an embodiment of the present invention.

[0352] According to one aspect of the present invention, in an electrode assembly of a cylindrical battery, the relative positions of the positive electrode end and the negative electrode end on the core side and the outer periphery side are adjusted, so that even if swelling occurs, the symmetry and circularity of the electrode assembly can be maintained and collapse of the core can be prevented or mitigated.

[0353] According to another aspect of the present invention, a cylindrical battery may include a pressure sensor capable of transmitting a pressure sensing signal via wireless communication, and continuously monitor changes in the swelling pressure applied by the outer circumferential surface of the electrode assembly to the inner circumferential surface of the battery housing, thereby easily detecting signs of core collapse.

[0354] According to yet another aspect of the present invention, a battery pack manufactured using a cylindrical battery including a pressure sensor, and a vehicle including the battery pack can be provided.

[0355] According to yet another aspect of the present invention, there can be provided an apparatus that can monitor changes in swelling pressure that an outer surface of an electrode assembly applies to an inner surface of a battery housing during charging and discharging of a cylindrical battery, and can detect signs of core collapse of the electrode assembly, and a battery management system including the apparatus.

[0356] As described above, the present invention has been described using limited embodiments and drawings, but the present invention is not limited thereto, and it goes without saying that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the technical spirit of the present invention and the equivalent scope of the claims. [Explanation of symbols]

[0357] 10 positive electrode 10a Positive electrode uncoated area 11 Negative electrode 11a Negative electrode uncoated area 12 Separation membrane 20 Current collector 21 Active material 22 Plain area 30 Current collector 30a lead 31 Current collector 32 Battery housing 33 Beading section 34 Cap assembly 34a Cap 34b Sealing gasket 34c connecting plate 35 Crimping section 36 Insulator 37 Cylindrical Battery 40 electrodes 41 Current collector 42 Active material layer 43 Plain area 44 insulating coating layer 45 electrode 50 electrodes 60 electrodes 61-minute sections 65 Electrode assembly 66 Independent area 80 Electrode assembly 101 Energy Conversion Unit 102 Energy storage unit 102a Transformers 102b bridge rectifier 102c capacitor 102d Boost circuit 102e Voltage adjustment unit 103 Pulse generator 104 Sensing part 105 Transponder 105e Antenna 110 Electrode assembly 142 Battery housing 143 Sealed body 143a Cap 143b Sealing gasket 143c connecting plate 143d Protrusion 144 First current collector 145 Second current collector 146 Insulators 147 Beading section 148 Crimping section 149 leads 151 Lead hole 152 Vent 171 Battery housing 172 terminals 173 Insulating gasket 174 Insulators 175 areas 175 parts 176 Second current collector 178 Sealed body 179 Vent 180 Beading section 181 Crimping section 190 Cylindrical Battery 200 Cylindrical Battery 210 Busbar 211 Body 212 First bus bar terminal 213 Second bus bar terminal 300 Swelling Pressure Monitoring Device 301 Receiving unit 302 Signal Processing Unit 303 Control Unit 304 Recording Department 305 Display section 306 Communications Department 307 Voltage measurement unit 308 Current measurement section 310 Computer Systems 400 battery pack 401 Cylindrical Battery 402 Pack Housing

Claims

1. an electrode assembly in which a first electrode, a second electrode, and a separator interposed between the first electrode and the second electrode are wound around a winding shaft to define a core and an outer circumferential surface; a battery housing including an open end and a closed portion facing the open end, the battery housing accommodating the electrode assembly in a space between the open end and the closed portion, the battery housing being electrically connected to one of the first electrode and the second electrode and having a first polarity; a seal that seals the open end of the battery housing; a terminal having a second polarity and electrically connected to the other of the first electrode and the second electrode, the terminal having a surface exposed to the outside; a pressure sensor interposed between an outer peripheral surface of the electrode assembly and an inner peripheral surface of the battery housing, the pressure sensor sensing a swelling pressure applied by the outer peripheral surface of the electrode assembly to the inner peripheral surface of the battery housing and outputting a pressure sensing signal to the outside.

2. The cylindrical battery according to claim 1 , wherein the pressure sensor has a sheet shape and is bonded to the outer circumferential surface of the electrode assembly along the shape of the outer circumferential surface of the electrode assembly.

3. the first electrode includes a first active material portion coated with an active material layer along the winding direction and a first uncoated portion not coated with an active material layer, and the second electrode includes a second active material portion coated with an active material layer along the winding direction and a second uncoated portion not coated with an active material layer, the first uncoated region and the second uncoated region are exposed to the outside of the separator and face each other along the winding axis direction, and are defined as electrode tabs themselves; 3. The cylindrical battery of claim 1, wherein, on a cross section of the electrode assembly perpendicular to the winding axis direction, a winding turn portion disposed between a line connecting the center of the core and the core-side end of the first active material portion and a line connecting the center of the core and the core-side end of the second active material portion is defined as a stress vulnerable region, and a winding turn portion disposed between a line connecting the center of the core and the outer circumferential end of the first active material portion and a line connecting the center of the core and the outer circumferential end of the second active material portion is defined as a stress amplification region, and the stress amplification region is spaced apart from the stress vulnerable region along a circumferential direction of the electrode assembly on the cross section.

4. 4. The cylindrical battery according to claim 3, wherein the pressure sensor is interposed between the outer circumferential surface of the electrode assembly and the inner circumferential surface of the battery housing so as to cover at least a portion of the stress amplification region.

5. the first electrode and the second electrode are a positive electrode and a negative electrode, respectively; an outer peripheral end of the second electrode is disposed closer to the outer periphery of the electrode assembly than an outer peripheral end of the first electrode; the separation film is interposed between an outer peripheral end of the second electrode and an outer peripheral end of the first electrode, In the circumferential direction of the electrode assembly, an outer peripheral end of the second electrode extends beyond an outer peripheral end of the first electrode along the winding direction of the electrode assembly, 5. The cylindrical battery according to claim 4, wherein the pressure sensor is interposed between the outer peripheral surface of the electrode assembly and the inner peripheral surface of the battery housing so as to intersect with a straight line connecting the center of the core and the outer peripheral end of the first electrode.

6. The cylindrical battery according to claim 1 or 2, wherein the pressure sensor outputs the pressure sensing signal to an outside via wireless communication.

7. a first bent surface region formed by bending a first uncoated portion of the first electrode toward the core; a first current collector coupled to the first folded surface region; a second bent surface region formed by bending the second uncoated portion of the second electrode toward the core; 4. The cylindrical battery of claim 3, further comprising a second current collector coupled to the second folded surface region.

8. The sealing body is a cap electrically connected to the first current collector; a crimping portion that is bent in a centripetal direction of the electrode assembly while enclosing the periphery of the cap, thereby fixing the periphery of the cap to the open end of the battery housing; 8. The cylindrical battery according to claim 7, further comprising: a sealing gasket interposed between the crimping portion and the periphery of the cap to seal the open end of the battery housing.

9. The cylindrical battery comprises: a rivet terminal that passes through a through hole formed in a closing portion of the battery housing and is riveted to an inner surface of the closing portion; an insulating gasket interposed between the rivet terminal and an inner peripheral surface of the through hole to electrically insulate the rivet terminal from the battery housing; 8. The cylindrical battery according to claim 7, wherein the terminal of the second polarity is the rivet terminal.

10. The outer circumferential surface of the battery housing adjacent to the open end of the battery housing further includes a beading portion pressed in the winding axis direction, 10. The cylindrical battery according to claim 9, wherein at least a portion of the periphery of the second current collector is in contact with the beading portion.

11. The open end of the battery housing further includes a crimping portion formed by bending the open end in the winding axis direction, the sealing body includes a cap placed on the beading portion, and a sealing gasket interposed between a periphery of the cap and an open end of the battery housing; 11. The cylindrical battery of claim 10, wherein one surface of the sealing gasket is tightly fitted toward the periphery of the cap by the crimping portion, and the other surface of the sealing gasket is tightly fitted toward the periphery of the second current collector that is in contact with the beading portion by the crimping portion.

12. 3. The cylindrical battery according to claim 1, wherein the cylindrical battery has a height-to-diameter ratio of greater than 0.

4.

13. 3. The cylindrical battery according to claim 1 or 2, wherein the form factor of the cylindrical battery is 46110, 4875, 48110, 4880, or 4680.

14. A battery pack comprising the cylindrical battery according to claim 1 or 2.

15. A motor vehicle comprising the battery pack of claim 14.

16. a battery housing having an open end and a closed portion opposite the open end, the battery housing housing containing the electrode assembly in a space between the open end and the closed portion, the battery housing being electrically connected to one of the first and second electrodes and having a first polarity; a sealing body sealing the open end of the battery housing; a terminal electrically connected to the other of the first and second electrodes and having a surface exposed to the outside, the terminal having a second polarity; and a pressure sensor interposed between the outer peripheral surface of the electrode assembly and the inner peripheral surface of the battery housing, the pressure sensor sensing a swelling pressure applied by the outer peripheral surface of the electrode assembly to the inner peripheral surface of the battery housing and outputting a pressure sensing signal to an outside via wireless communication, a receiving unit that receives the pressure sensing signal transmitted from the pressure sensor through wireless communication; a signal processing unit that demodulates the pressure sensing signal into an original signal; a control unit that determines the swelling pressure from the demodulated pressure sensing signal and generates time-series data of the swelling pressure.

17. the pressure sensor is configured to transmit, via wireless communication, a reference surface acoustic wave and a sensing surface acoustic wave having an amplitude different from that of the reference surface acoustic wave in response to the swelling pressure; 17. The cylindrical battery swelling pressure monitoring device of claim 16, wherein the control unit is configured to determine an amplitude difference between the reference surface acoustic wave and the sensing surface acoustic wave, and to determine a swelling pressure corresponding to the determined amplitude difference using a predefined correlation between the amplitude difference and the swelling pressure.

18. 18. The swelling pressure monitoring device for a cylindrical battery according to claim 16 or 17, wherein the control unit is configured to generate a swelling pressure profile from the time-series data of the swelling pressure, and, when at least one minimum peak is identified in the swelling pressure profile, diagnose that there is a symptom of core collapse of the electrode assembly, and output a diagnosis result.

19. 18. The swelling pressure monitoring device for a cylindrical battery according to claim 16, wherein the control unit is configured to generate a swelling pressure profile from the time-series data of the swelling pressure, generate a differential swelling pressure profile by differentiating the swelling pressure profile with respect to time, and, when at least one peak is identified in the differential swelling pressure profile, diagnose that there is a symptom of core collapse of the electrode assembly and output a diagnosis result.

20. Further comprising a voltage measuring unit for measuring a voltage of the cylindrical battery; The control unit periodically receiving voltage measurement values ​​from the voltage measurement unit to generate a voltage profile; generating a differential voltage profile through time or state-of-charge differentiation of the voltage profile; 18. The cylindrical battery swelling pressure monitoring device according to claim 16 or 17, wherein, when the swelling pressure is equal to or greater than a critical value and at least one peak is identified in the differential voltage profile, the device is configured to diagnose that there is a symptom of core collapse of the electrode assembly and output a diagnosis result.

21. further comprising a display operably coupled to the control unit; The device for monitoring swelling pressure of a cylindrical battery according to claim 18 , wherein the control unit is configured to output the diagnosis result through the display unit.

22. further comprising a communication unit operably coupled to the control unit; The device for monitoring swelling pressure of a cylindrical battery according to claim 18 , wherein the control unit is configured to transmit the diagnosis result to a computer system through the communication unit.

23. The device for monitoring swelling pressure of a cylindrical battery according to claim 18 , wherein the diagnosis result includes a warning message or a message requesting inspection.

24. A battery management system comprising the cylindrical battery swelling pressure monitoring device according to claim 16 or 17.

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