Secondary battery including thermal runaway prevention structure

Abstract

The present invention provides a secondary battery which prevents thermal runaway. A secondary battery according to an embodiment of the present invention comprises: a battery unit including a cathode, an anode, and a separator; a housing unit which accommodates the battery unit; and an oxygen absorption unit which is disposed on the inner surface of the housing unit and, when the temperature rises, absorbs oxygen inside the housing unit through an oxidation reaction.

Description

Secondary battery including thermal runaway prevention structure

[0001] The technical idea of ​​the present invention relates to a secondary battery, and more particularly, to a secondary battery including a thermal runaway prevention structure.

[0002] Secondary batteries are highly applicable across a wide range of product groups and possess electrical properties such as high energy density. Therefore, they are used in portable devices, electric or hybrid vehicles powered by electrical power sources, and power storage devices. These batteries are attracting attention as a new energy source for environmental friendliness and energy efficiency, as they offer the primary advantage of dramatically reducing fossil fuel use and produce no byproducts from energy use.

[0003] Unlike small mobile devices, medium- to large-sized devices such as automobiles require high output and large capacity. Therefore, medium- to large-sized battery modules are used, electrically connecting multiple battery cells. As multiple battery cells are stacked, if the temperature of one battery cell exceeds a certain level, nearby cells may be affected, potentially triggering thermal runaway. This thermal runaway can accelerate and potentially cause battery cell explosion. Therefore, there is a growing demand for technologies that prevent thermal runaway in secondary batteries.

[0004] The technical problem to be achieved by the technical idea of ​​the present invention is to provide a secondary battery including a thermal runaway prevention structure.

[0005] However, these tasks are exemplary and the technical idea of ​​the present invention is not limited thereto.

[0006] In one aspect of the present invention, a secondary battery may include a battery unit including a cathode, an anode, and a separator; a housing unit that accommodates the battery unit; and an oxygen absorption unit that is disposed on an inner surface of the housing unit and absorbs oxygen inside the housing unit by an oxidation reaction when the temperature rises.

[0007] In one embodiment of the present invention, the oxygen absorption unit includes a first vanadium oxide (VO2), and when the temperature rises, the first vanadium oxide (VO2) changes into a second vanadium oxide (V2O5), thereby allowing oxygen inside the housing unit to be absorbed.

[0008] In one embodiment of the present invention, the oxygen absorbing portion may be doped with a doping element of 1 wt% to 10 wt%.

[0009] In one embodiment of the present invention, the device may further include: a first current collector arranged in contact with one side of the cathode; a first metal-insulator transition portion arranged in contact with one side of the first current collector and changing from an insulator to a conductor when the temperature rises; and a first ground portion electrically connected to the first metal-insulator transition portion.

[0010] In one embodiment of the present invention, the first metal-insulator transition portion is an insulator at a first temperature and changes into a conductor at a second temperature higher than the first temperature, thereby allowing current to flow from the first current collector to the first ground portion.

[0011] In one embodiment of the present invention, the first metal-insulator transition region may include a first vanadium oxide (VO2).

[0012] In one embodiment of the present invention, the first metal-insulator transition region may be doped with a doping element of 1 wt% to 10 wt%.

[0013] In one embodiment of the present invention, a first thermal conductivity control unit may be further included between the first current collector and the first metal-insulator transition unit.

[0014] In one embodiment of the present invention, the device may further include a second current collector arranged in contact with one side of the anode; a second metal-insulator transition portion arranged in contact with one side of the second current collector and changing from an insulator to a conductor when the temperature rises; and a second ground portion electrically connected to the second metal-insulator transition portion.

[0015] In one embodiment of the present invention, the second metal-insulator transition portion is an insulator at a first temperature and changes into a conductor at a second temperature higher than the first temperature, thereby allowing current to flow from the second current collector to the second grounding portion.

[0016] In one embodiment of the present invention, the second metal-insulator transition region may include first vanadium oxide (VO2).

[0017] In one embodiment of the present invention, a second heat conduction control unit may be further included between the second current collector and the second metal-insulator transition unit.

[0018] In one embodiment of the present invention, the device may include: a first current collector arranged in contact with one side of the cathode; a first metal-insulator transition portion arranged in contact with one side of the first current collector and changing from an insulator to a conductor when temperature increases; a first control portion electrically connected to the first metal-insulator transition portion; and a first ground portion electrically connected to the first control portion.

[0019] In one embodiment of the present invention, the first metal-insulator transition portion is an insulator at a first temperature and changes into a conductor at a second temperature higher than the first temperature to provide a sensing signal to the first control portion, and the first control portion can cause current to flow from the first current collector to the first ground portion in response to the sensing signal.

[0020] In one embodiment of the present invention, the first metal-insulator transition region may include a first vanadium oxide (VO2).

[0021] In one embodiment of the present invention, a first thermal conductivity control unit may be further included between the first current collector and the first metal-insulator transition unit.

[0022] In one embodiment of the present invention, the device may further include: a second current collector arranged in contact with one side of the anode; a second metal-insulator transition portion arranged in contact with one side of the second current collector and changing from an insulator to a conductor when the temperature rises; a second control portion electrically connected to the second metal-insulator transition portion; and a second ground portion electrically connected to the second control portion.

[0023] In one embodiment of the present invention, the second metal-insulator transition portion is an insulator at a first temperature and changes into a conductor at a second temperature higher than the first temperature to provide a sensing signal to the second control portion, and the second control portion can cause current to flow from the second current collector to the second ground portion based on the sensing signal.

[0024] In one embodiment of the present invention, the second metal-insulator transition region may include first vanadium oxide (VO2).

[0025] In one embodiment of the present invention, a second heat conduction control unit may be further included between the second current collector and the second metal-insulator transition unit.

[0026] A secondary battery according to another aspect of the present invention may include a battery unit including a cathode, an anode, and a separator; a first current collector arranged in contact with one side of the cathode; a first metal-insulator transition unit arranged in contact with one side of the first current collector and changing from an insulator to a conductor when temperature increases; and a first ground unit electrically connected to the first metal-insulator transition unit.

[0027] According to another aspect of the present invention, a secondary battery may include a battery unit including a cathode, an anode, and a separator; a first current collector arranged in contact with one side of the cathode; a first metal-insulator transition unit arranged in contact with one side of the first current collector and changing from an insulator to a conductor when a temperature rises; a first control unit electrically connected to the first metal-insulator transition unit; and a first ground unit electrically connected to the first control unit.

[0028] The secondary battery according to the technical idea of ​​the present invention includes an oxygen absorption portion made of a metal-insulator transition material such as vanadium oxide as a thermal runaway prevention structure inside the housing portion, so that when the temperature rises, oxygen inside the housing portion is absorbed and removed by an oxidation reaction, thereby preventing thermal runaway.

[0029] In addition, the secondary battery includes a metal-insulator transition portion made of a metal-insulator transition material such as vanadium oxide as a thermal runaway prevention structure, so that when the temperature rises, it changes into a conductor and allows excess current to flow to the ground portion, thereby preventing thermal runaway.

[0030] The effects of the present invention described above are illustrative, and the scope of the present invention is not limited by these effects.

[0031] Figures 1 to 4 are schematic diagrams illustrating secondary batteries according to one embodiment of the present invention.

[0032] Figure 5 is a schematic diagram showing a battery section of a secondary battery according to one embodiment of the present invention.

[0033] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Embodiments of the present invention are provided to more completely explain the technical idea of ​​the present invention to those skilled in the art. The following embodiments may be modified in various different forms, and the scope of the technical idea of ​​the present invention is not limited to the following embodiments. Rather, these embodiments are provided to more faithfully and completely convey the technical idea of ​​the present invention to those skilled in the art. Like reference numerals throughout this specification denote like elements. Furthermore, various elements and areas in the drawings are schematically drawn. Therefore, the technical idea of ​​the present invention is not limited by the relative sizes or intervals drawn in the attached drawings.

[0034] Thermal runaway in secondary batteries occurs when the temperature within the battery rises abnormally due to factors such as a concentrated current. This causes the solid electrolyte interface and electrolyte to decompose, further increasing the temperature through an exothermic reaction. The cathode and electrolyte then react, and the electrolyte further decomposes, generating oxygen and generating heat. Therefore, to prevent thermal runaway, it is necessary to eliminate overcurrent and the generated oxygen.

[0035] Figures 1 to 4 are schematic diagrams illustrating secondary batteries according to one embodiment of the present invention.

[0036] Referring to FIG. 1, a secondary battery (100) may include a battery portion (110), a housing portion (190), and an oxygen absorption portion (180).

[0037] The battery unit (110) may include a cathode (111), an anode (112), and a separator (113). The battery unit (110) will be described in detail with reference to FIG. 5.

[0038] The housing portion (190) can accommodate the battery portion (110). The housing portion (190) can be made of metal, for example, aluminum, an aluminum alloy, etc.

[0039] The oxygen absorption unit (180) may be arranged on the inner surface of the housing unit (190). The oxygen absorption unit (180) may be arranged on the entire inner surface of the housing unit (190) or may be arranged on a portion of the inner surface.

[0040] The oxygen absorption unit (180) can function as a thermal runaway prevention structure. The oxygen absorption unit (180) can absorb oxygen within the housing unit (190) through an oxidation reaction when the temperature rises.

[0041] The above oxygen may flow into the secondary battery (100) from the outside due to cracking or may be generated from the electrolyte contained in the battery unit (110).

[0042] The above oxygen absorption unit (180) may include a first vanadium oxide (VO2). When the temperature rises and reaches the oxide transition temperature, the first vanadium oxide (VO2) changes into a second vanadium oxide (V2O5) as shown in Equation 1 below, thereby absorbing and removing oxygen within the housing unit (190), thereby preventing thermal runaway.

[0043] [Formula 1] 4VO2+ O2-> 2V2O5

[0044] In addition, since the reaction in which the first vanadium oxide (VO2) is changed into the second vanadium oxide (V2O5) is an endothermic reaction, the temperature can be lowered, and thus thermal runaway can be additionally prevented.

[0045] The above oxide transition temperature may be, for example, in the range of 400°C to 600°C.

[0046] The oxygen absorption unit (180) may include a doping element to change the oxide transition element. For example, the oxygen absorption unit (180) may be doped with the doping element at 1 wt% to 10 wt%. The oxygen absorption unit (180) may be doped with, for example, magnesium (Mg), copper (Cu), zinc (Zn), tungsten (W), niobium (Nb), molybdenum (Mo), tantalum (Ta), fluorine (F), or a mixture thereof at 1 wt% to 10 wt%, thereby reducing the oxide transition temperature. Alternatively, the oxygen absorption unit (180) may be doped with, for example, chromium (Cr), iron (Fe), or a mixture thereof at 1 wt% to 10 wt%, thereby increasing the oxide transition temperature.

[0047] In addition, the oxide transition temperature may change depending on the structure and process conditions of the oxygen absorption unit (180), and the transition width and hysteresis may also change.

[0048] Additionally, the oxide transition temperature can be changed, for example, reduced, by forming a defect in the oxygen absorption portion (180).

[0049] The secondary battery (100) may further include a first current collector (120), a first metal-insulator transition portion (130), and a first ground portion (140).

[0050] The housing portion (190) can accommodate a first current collector portion (120), a first metal-insulator transition portion (130), and a first ground portion (140).

[0051] The first current collector (120) may be arranged in contact with one side of the cathode (111). The first current collector (120) may collect current from the cathode (111). The first current collector (120) may include a conductive material, for example, a metal, for example, aluminum (Al), copper (Cu), or an alloy thereof.

[0052] The first metal-insulator transition portion (130) may be arranged in contact with one side of the first current collector (120). The cathode (111) and the first metal-insulator transition portion (130) may be arranged on opposite sides with respect to the first current collector (120).

[0053] The first metal-insulator transition region (130) can function as a thermal runaway prevention structure. The first metal-insulator transition region (130) can change from an insulator to a conductor when the temperature increases. The first metal-insulator transition region (130) is an insulator at a first temperature and can change into a conductor at a second temperature higher than the first temperature. The first temperature can be, for example, a temperature below 60°C, for example, in the range of 0°C to 60°C. The second temperature can be a phase transition temperature at which the metal-insulator transitions from an insulator to a conductor, for example, in the range of 60°C to 80°C, for example, in the range of 65°C to 70°C.

[0054] The first metal-insulator transition region (130) may include a metal-insulator transition (MIT) material, for example, first vanadium oxide (VO2). In addition, the first metal-insulator transition region (130) may include a doping element to change the second temperature. For example, the first metal-insulator transition region (130) may be doped with 1 wt% to 10 wt% of the doping element. The first metal-insulator transition region (130) may be doped with, for example, magnesium (Mg), copper (Cu), zinc (Zn), tungsten (W), niobium (Nb), molybdenum (Mo), tantalum (Ta), fluorine (F), or a mixture thereof, at 1 wt% to 10 wt%, thereby reducing the second temperature. Alternatively, the first metal-insulator transition (130) may be doped with, for example, 1 wt% to 10 wt% of chromium (Cr), iron (Fe), or a mixture thereof, thereby increasing the second temperature.

[0055] Additionally, the second temperature may change depending on the structure and process conditions of the first metal-insulator transition region (130), and the transition width and hysteresis may also change.

[0056] The first grounding portion (140) can be electrically connected to the first metal-insulator transition portion (130). When the first metal-insulator transition portion (130) increases in temperature and changes into a conductor, the first current collector (120) is electrically connected to the first grounding portion (140), so that current can flow from the first current collector (120) to the first grounding portion (140). Therefore, the overcurrent within the battery portion (110) can be removed, thereby preventing thermal runaway. In addition, since the reaction in which the first vanadium oxide (VO2) changes from an insulator to a conductor is an endothermic reaction, the temperature can be lowered, thereby further preventing thermal runaway.

[0057] Additionally, the secondary battery (100) may further include a second current collector (122), a second metal-insulator transition portion (132), and a second ground portion (142).

[0058] Additionally, the housing portion (190) can accommodate a second current collector (122), a second metal-insulator transition portion (132), and a second ground portion (142).

[0059] The second current collector (122) may be arranged in contact with one side of the anode (112). The second current collector (122) may collect current from the anode (112). The second current collector (122) may include a conductive material, for example, a metal, for example, aluminum (Al), copper (Cu), or an alloy thereof. The first current collector (120) and the second current collector (122) may include the same material or different materials.

[0060] The second metal-insulator transition portion (132) may be arranged in contact with one side of the second current collector (122). The anode (112) and the second metal-insulator transition portion (132) may be arranged on opposite sides with respect to the second current collector (122).

[0061] The second metal-insulator transition region (132) can function as a thermal runaway prevention structure. The second metal-insulator transition region (132) can change from an insulator to a conductor when the temperature increases. The second metal-insulator transition region (132) is an insulator at the first temperature and can change into a conductor at the second temperature that is higher than the first temperature. The first temperature can be, for example, a temperature below 60°C, and can be, for example, in the range of 0°C to 60°C. The second temperature can be, for example, in the range of 60°C to 80°C, and can be, for example, in the range of 65°C to 70°C.

[0062] The second metal-insulator transition region (132) may include a metal-insulator transition (MIT) material, for example, first vanadium oxide (VO2). The second metal-insulator transition region (132) may include a doping element to change the second temperature. The second metal-insulator transition region (132) may be doped with 1 wt% to 10 wt% of the doping element. The second metal-insulator transition region (132) may be doped with, for example, magnesium (Mg), copper (Cu), zinc (Zn), tungsten (W), niobium (Nb), molybdenum (Mo), tantalum (Ta), fluorine (F), or a mixture thereof, for example, 1 wt% to 10 wt%, thereby reducing the second temperature. Alternatively, the second metal-insulator transition region (132) may be doped with, for example, 1 wt% to 10 wt% of chromium (Cr), iron (Fe), or a mixture thereof, thereby increasing the second temperature.

[0063] Additionally, the second temperature may change depending on the structure and process conditions of the second metal-insulator transition region (132), and the transition width and hysteresis may also change.

[0064] The second metal-insulator transition region (132) may include the same material as the first metal-insulator transition region (130) or may include different materials.

[0065] The second grounding portion (142) can be electrically connected to the second metal-insulator transition portion (132). When the second metal-insulator transition portion (132) increases in temperature and changes into a conductor, the second current collector (122) is electrically connected to the second grounding portion (142), so that current can flow from the second current collector (122) to the second grounding portion (142). Therefore, the overcurrent within the battery portion (110) can be removed, thereby preventing thermal runaway. In addition, since the reaction in which the first vanadium oxide (VO2) changes from an insulator to a conductor is an endothermic reaction, the temperature can be lowered, thereby preventing thermal runaway.

[0066] The first grounding portion (140) and the second grounding portion (142) may be provided as separate components or as integrated components.

[0067] Referring to FIG. 2, the secondary battery (200) may include a battery section (110), a first current collector section (120), a first metal-insulator transition section (130), and a first ground section (140).

[0068] In addition, the secondary battery (200) may further include a second current collector (122), a second metal-insulator transition portion (132), and a second ground portion (142). Components that overlap with those described with reference to Fig. 1 will be omitted.

[0069] Additionally, the secondary battery (200) may further include a first thermal conductivity control unit (160) interposed between the first current collector (120) and the first metal-insulator transition unit (130).

[0070] The first thermal conductivity control unit (160) can control thermal conduction from the first current collector (120) to the first metal-insulator transition unit (130) and may include, for example, an insulator having lower thermal conductivity than metal. The first thermal conductivity control unit (160) may include, for example, ceramic fibers made of an inorganic composite such as glass fibers, silica glass, or alumina.

[0071] The first heat conduction control unit (160) can slow down the heat conduction from the first current collector (120) to the first metal-insulator transition unit (130), thereby controlling the temperature of the first metal-insulator transition unit (130) to be lower than the temperature of the first current collector (120).

[0072] For example, if the phase transition temperature of the first metal-insulator transition region (130) is 70°C and the allowable temperature of the battery section (110) is a temperature higher than 70°C, for example, 100°C, in the absence of the first thermal conductivity control section (160), when the temperature of the battery section (110) reaches 70°C, current flows to the first ground section (140), which reduces the efficiency of the battery section (110). At this time, the first metal-insulator transition region (130) may be treated by doping or the like to increase the phase transition temperature to 100°C, thereby increasing the efficiency of the battery section (110). Alternatively, by further including the first heat conduction control unit (160), the efficiency of the battery unit (110) can be increased by slowing down the heat transfer so that the first metal-insulator transition unit (130) reaches the phase transition temperature of 70°C when the battery unit (110) is at 100°C.

[0073] Additionally, the secondary battery (200) may further include a second thermal conductivity control unit (162) interposed between the second current collector (122) and the second metal-insulator transition unit (132).

[0074] The second thermal conductivity control unit (162) can control thermal conduction from the second current collector (122) to the second metal-insulator transition unit (132) and can include, for example, an insulator having lower thermal conductivity than metal. The second thermal conductivity control unit (162) can include, for example, ceramic fibers made of an inorganic composite such as glass fibers, silica glass, or alumina.

[0075] The second heat conduction control unit (162) can slow down the heat conduction from the second current collector (122) to the second metal-insulator transition unit (132), thereby controlling the temperature of the second metal-insulator transition unit (132) to be lower than the temperature of the second current collector (122).

[0076] The first heat conduction control unit (160) and the second heat conduction control unit (162) may contain the same material or different materials.

[0077] Referring to FIG. 3, the secondary battery (300) may include a battery unit (110), a first current collector (120), a first metal-insulator transition unit (130), a first ground unit (140), and a first control unit (150).

[0078] The battery unit (110) may include a cathode (111), an anode (112), and a separator (113).

[0079] The first current collector (120) may be arranged in contact with one side of the cathode (111). The first current collector (120) may collect current from the cathode (111). The first current collector (120) may include a conductive material, for example, a metal, for example, aluminum (Al), copper (Cu), or an alloy thereof.

[0080] The first metal-insulator transition portion (130) may be arranged in contact with one side of the first current collector (120). The cathode (111) and the first metal-insulator transition portion (130) may be arranged on opposite sides with respect to the first current collector (120).

[0081] The first metal-insulator transition region (130) can change from an insulator to a conductor when the temperature increases. The first metal-insulator transition region (130) is an insulator at a first temperature and can change into a conductor at a second temperature that is higher than the first temperature. The first temperature can be, for example, a temperature below 60°C, for example, a range from 0°C to 60°C. The second temperature can be a phase transition temperature at which the metal changes from an insulator to a conductor, for example, a range from 60°C to 80°C, for example, a range from 65°C to 70°C.

[0082] The first metal-insulator transition region (130) may include a metal-insulator transition (MIT) material, for example, first vanadium oxide (VO2). In addition, the first metal-insulator transition region (130) may include a doping element to change the second temperature. For example, the first metal-insulator transition region (130) may be doped with the above-described doping element at 1 wt% to 10 wt%.

[0083] The above first metal-insulator transition portion (130) is an insulator at a first temperature and changes into a conductor at a second temperature higher than the first temperature, thereby providing a sensing signal to the first control portion (150).

[0084] The first grounding unit (140) can be electrically connected to the first control unit (150).

[0085] The first control unit (150) can be electrically connected to the first metal-insulator transition unit (130). The first control unit (150) can cause current to flow from the first current collector (120) to the first ground unit (140) based on the sensing signal. Therefore, overcurrent within the battery unit (110) can be removed, thereby preventing thermal runaway. In addition, since the reaction in which the first vanadium oxide (VO2) changes from an insulator to a conductor is an endothermic reaction, the temperature can be lowered, thereby preventing thermal runaway. In order to change the current path in this way, the first control unit (150) can have a switch configuration.

[0086] That is, when the first metal-insulator transition portion (130) is at the first temperature, current flows from the first current collector (120) to the load. On the other hand, when the first metal-insulator transition portion (130) is at the second temperature, the sensing signal is provided to the first control portion (150), and the first control portion (150) can block the current flowing to the load and allow the current to flow to the first ground portion (140) according to the sensing signal.

[0087] Additionally, the secondary battery (300) may further include a second current collector (122), a second metal-insulator transition unit (132), a second control unit (152), and a second ground unit (142).

[0088] The second current collector (122) may be arranged in contact with one side of the anode (112). The second current collector (122) may collect current from the anode (112). The second current collector (122) may include a conductive material, for example, a metal, for example, aluminum (Al), copper (Cu), or an alloy thereof. The first current collector (120) and the second current collector (122) may include the same material or different materials.

[0089] The second metal-insulator transition portion (132) may be arranged in contact with one side of the second current collector (122). The anode (112) and the second metal-insulator transition portion (132) may be arranged on opposite sides with respect to the second current collector (122).

[0090] The second metal-insulator transition region (132) can change from an insulator to a conductor when the temperature increases. The second metal-insulator transition region (132) is an insulator at the first temperature and can change to a conductor at the second temperature that is higher than the first temperature. The first temperature can be, for example, a temperature below 60°C, and can be, for example, in the range of 0°C to 60°C. The second temperature can be a phase transition temperature at which the material changes from an insulator to a conductor, and can be, for example, in the range of 60°C to 80°C, and can be, for example, in the range of 65°C to 70°C.

[0091] The second metal-insulator transition region (132) may include a metal-insulator transition (MIT) material, for example, vanadium oxide (VO2). The second metal-insulator transition region (132) may include a doping element to change the second temperature. For example, the second metal-insulator transition region (132) may be doped with the above-described doping element at 1 wt% to 10 wt%. The second metal-insulator transition region (132) may include the same material as the first metal-insulator transition region (130) or may include different materials.

[0092] The second metal-insulator transition portion (132) is an insulator at a first temperature and changes into a conductor at a second temperature higher than the first temperature, thereby providing a sensing signal to the second control portion (152).

[0093] The second grounding unit (142) can be electrically connected to the second control unit (152).

[0094] The second control unit (152) may be electrically connected to the second metal-insulator transition unit (132). The second control unit (152) may allow current to flow from the second current collector (122) to the second ground unit (142) based on the sensing signal. Accordingly, overcurrent within the battery unit (110) may be removed, thereby preventing thermal runaway. In addition, since the reaction in which the first vanadium oxide (VO2) changes from an insulator to a conductor is an endothermic reaction, the temperature may be lowered, thereby preventing thermal runaway. In order to change the current path in this way, the second control unit (152) may have a switch configuration.

[0095] That is, when the second metal-insulator transition portion (132) is at the first temperature, current flows from the second current collector (122) to the load. On the other hand, when the second metal-insulator transition portion (132) is at the second temperature, the sensing signal is provided to the second control portion (152), and the second control portion (152) can block the current flowing to the load and allow the current to flow to the second ground portion (142) according to the sensing signal.

[0096] The first grounding portion (140) and the second grounding portion (142) may be provided as separate components or as integrated components.

[0097] The first control unit (150) and the second control unit (152) may be provided as separate components or as integrated components.

[0098] Referring to FIG. 4, the secondary battery (400) may include a battery unit (110), a first current collector (120), a first metal-insulator transition unit (130), a first ground unit (140), and a first control unit (150).

[0099] In addition, the secondary battery (400) may further include a second current collector (122), a second metal-insulator transition portion (132), a second ground portion (142), and a second control portion (152). Components that overlap with those described with reference to FIG. 3 will be omitted.

[0100] Additionally, the secondary battery (400) may further include a first thermal conductivity control unit (160) interposed between the first current collector (120) and the first metal-insulator transition unit (130).

[0101] The first thermal conductivity control unit (160) can control thermal conduction from the first current collector (120) to the first metal-insulator transition unit (130), and may include, for example, an insulator having lower thermal conductivity than a metal.

[0102] The first heat conduction control unit (160) can slow down the heat conduction from the first current collector (120) to the first metal-insulator transition unit (130), thereby controlling the temperature of the first metal-insulator transition unit (130) to be lower than the temperature of the first current collector (120).

[0103] Additionally, the secondary battery (400) may further include a second thermal conductivity control unit (162) interposed between the second current collector (122) and the second metal-insulator transition unit (132).

[0104] The second thermal conductivity control unit (162) can control thermal conduction from the second current collector (122) to the second metal-insulator transition unit (132), and may include, for example, an insulator having lower thermal conductivity than a metal.

[0105] The second heat conduction control unit (162) can slow down the heat conduction from the second current collector (122) to the second metal-insulator transition unit (132), thereby controlling the temperature of the second metal-insulator transition unit (132) to be lower than the temperature of the second current collector (122).

[0106] The first heat conduction control unit (160) and the second heat conduction control unit (162) may include the same material.

[0107] Figure 5 is a schematic diagram showing a battery section of a secondary battery according to one embodiment of the present invention.

[0108] Referring to FIG. 5, the battery unit (110) includes a cathode (111), an anode (112), and a separator (113) arranged alternately.

[0109] For example, in FIG. 5, from the front to the back, a first separator layer (113_1), a first cathode layer (111_1), a second separator layer (113_2), a first anode layer (112_1), a third separator layer (113_3), a second cathode layer (111_2), a fourth separator layer (113_4), a second anode layer (112_2), and a fifth separator layer (113_5) may be arranged. That is, the separator (113) may be arranged between the cathode (111) and the anode (112) to separate them from each other.

[0110] The cathode (111), anode (112), and separator (113) each have a sheet shape and may have a wound shape together.

[0111] Below, the materials constituting the cathode (111), the anode (112), and the separator (113) will be described. However, this is exemplary and the technical idea of ​​the present invention is not limited thereto.

[0112] The cathode (111) may include a cathode current collector and a cathode active material formed on the cathode current collector.

[0113] The above positive electrode active material may be a compound capable of reversible intercalation and deintercalation of lithium (lithiated intercalation compound). Specifically, at least one compound oxide of lithium and a metal such as cobalt, manganese, nickel, or a combination thereof may be used. The above positive electrode active material may include lithium and Ni, Co, Mn, Al, Cr, Fe, Mg, La, Ce, Sr, V, Ti, Mo, Sc, Y, rare earth elements, etc.

[0114] The cathode (111) includes a binder and may optionally include a conductive material.

[0115] The above binder serves to adhere the positive electrode active material particles well to each other and also to adhere the positive electrode active material well to the cathode current collector, and representative examples thereof include, but are not limited to, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, nylon, etc.

[0116] The above conductive material is used to provide conductivity to the electrode, and any material that does not cause chemical change and is electronically conductive in the battery to be constructed can be used. For example, natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, metal powders such as copper, nickel, aluminum, and silver, metal fibers, etc. can be used, and also one or more types of conductive materials such as polyphenylene derivatives can be used in combination.

[0117] The anode (112) may include an anode current collector and an anode active material formed on the anode current collector.

[0118] The anode active material may include a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0119] The material capable of reversibly intercalating / deintercalating the lithium ions may be a carbon material, for example, crystalline carbon, amorphous carbon, or a combination thereof. Examples of the crystalline carbon include graphite such as natural graphite or artificial graphite in an amorphous, plate-like, flake-like, spherical, or fibrous form, and examples of the amorphous carbon include soft carbon (low-temperature calcined carbon) or hard carbon, mesophase pitch carbide, calcined coke, etc.

[0120] As the above lithium metal alloy, an alloy of lithium with a metal such as Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al or Sn can be used.

[0121] Materials capable of doping and dedoping the lithium include Si, SiO, Si-C composites, Si-Q alloys (wherein Q is an alkali metal, an alkaline earth metal, a group 13 to 16 element, a transition metal, a rare earth element, or a combination thereof, and is not Si), Sn, SnO2, Sn-C composites, Sn-R (wherein R is an alkali metal, an alkaline earth metal, a group 13 to 16 element, a transition metal, a rare earth element, or a combination thereof).

[0122] Examples of the above transition metal oxides include vanadium oxide, lithium vanadium oxide, etc.

[0123] The anode (112) includes a binder and may optionally include a conductive material.

[0124] The above binder serves to adhere the negative electrode active material particles well to each other and also to adhere the negative electrode active material well to the anode current collector, and examples thereof include, but are not limited to, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, nylon, etc.

[0125] The above conductive material is used to provide conductivity to the electrode, and any material that does not cause chemical changes in the battery to be formed and is electronically conductive can be used. For example, a conductive material including a carbon-based material such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, etc.; a metal-based material such as metal powder or metal fiber such as copper, nickel, aluminum, silver, etc.; a conductive polymer such as a polyphenylene derivative; or a mixture thereof can be used.

[0126] The anode current collector may be a copper foil, a nickel foil, a stainless steel foil, a titanium foil, a nickel foam, a copper foam, a polymer substrate coated with a conductive metal, or a combination thereof.

[0127] A separator (113) can separate the cathode (111) and the anode (112) and provide a passage for lithium ions to move. The separator (113) can include an electrolyte.

[0128] The above electrolyte may include a non-aqueous organic solvent and a lithium salt.

[0129] The non-aqueous organic solvent acts as a medium through which ions involved in the electrochemical reaction of the battery can move. Carbonate-based, ester-based, ether-based, ketone-based, alcohol-based, or aprotic solvents can be used as the non-aqueous organic solvent.

[0130] The lithium salt is a substance that is dissolved in the non-aqueous organic solvent and acts as a source of lithium ions within the battery, enabling the basic operation of a lithium secondary battery and promoting the movement of lithium ions between the positive and negative electrodes. Representative examples of the lithium salt may include LiPF6, LiBF4, LiSbF6, LiAsF6, LiC4F9SO3, LiClO4, LiAlO2, LiAlCl4, LiCl, LiI, LiB(C2O4)2, or a combination thereof.

[0131] Referring to FIGS. 1 to 4, the secondary battery (100, 200, 300, 400) includes an oxygen absorption unit (180). However, the present invention is not limited thereto, and the secondary battery (100, 200, 300, 400) may not include the oxygen absorption unit (180). Even in this case, since the first metal-insulator transition unit (130) and / or the second metal-insulator transition unit (132) composed of a metal-insulator transition material are included as a thermal runaway prevention structure, when the temperature rises, they change into conductors to allow excessive current to flow to the first ground unit (140) and / or the second battery unit (142), thereby preventing thermal runaway.

[0132] Secondary batteries according to the technical concept of the present invention can be implemented in various shapes, such as cylindrical, square, coin-shaped, and pouch-shaped, and can be classified into bulk and thin-film types depending on their size. The structure and manufacturing method of such secondary batteries are widely known in the art, so a detailed description will be omitted.

[0133] It will be apparent to a person skilled in the art to which the technical idea of ​​the present invention pertains that the technical idea of ​​the present invention described above is not limited to the above-described embodiments and the attached drawings, and that various substitutions, modifications, and changes are possible within a scope that does not depart from the technical idea of ​​the present invention.

[0134] Using the present invention, a secondary battery including a thermal runaway prevention structure can be manufactured.

Claims

1. A battery section including a cathode, an anode, and a separator; A housing portion that accommodates the above battery portion; A secondary battery comprising an oxygen absorption unit disposed on the inner surface of the housing portion and absorbing oxygen inside the housing portion by an oxidation reaction when the temperature rises.

2. In claim 1, A secondary battery in which the oxygen absorption unit includes a first vanadium oxide (VO2), and absorbs oxygen inside the housing unit by changing the first vanadium oxide (VO2) into a second vanadium oxide (V2O5) when the temperature rises.

3. In claim 2, A secondary battery, wherein the oxygen absorbing portion is doped with 1 to 10 wt% of a doping element.

4. In claim 1, A first current collector arranged in contact with one side of the cathode; A first metal-insulator transition portion that is placed in contact with one side of the first current collector and changes from an insulator to a conductor when the temperature rises; and A secondary battery further comprising a first grounding portion electrically connected to the first metal-insulator transition portion.

5. In claim 4, A secondary battery, wherein the first metal-insulator transition region is an insulator at a first temperature and changes into a conductor at a second temperature higher than the first temperature, thereby allowing current to flow from the first current collector to the first grounding region.

6. In claim 4, A secondary battery, wherein the first metal-insulator transition region comprises a first vanadium oxide (VO2).

7. In claim 4, A secondary battery, wherein the first metal-insulator transition region is doped with 1 to 10 wt% of a doping element.

8. In claim 4, A secondary battery further comprising a first thermal conductivity control unit interposed between the first current collector and the first metal-insulator transition unit.

9. In claim 1, A second current collector arranged in contact with one side of the anode; A second metal-insulator transition portion that is placed in contact with one side of the second current collector and changes from an insulator to a conductor when the temperature rises; and A secondary battery further comprising a second grounding portion electrically connected to the second metal-insulator transition portion.

10. In claim 9, A secondary battery, wherein the second metal-insulator transition portion is an insulator at a first temperature and changes into a conductor at a second temperature higher than the first temperature, thereby allowing current to flow from the second current collector to the second ground portion.

11. In claim 9, A secondary battery, wherein the second metal-insulator transition region comprises a first vanadium oxide (VO2).

12. In claim 9, A secondary battery further comprising a second thermal conductivity control unit interposed between the second current collector and the second metal-insulator transition unit.

13. In claim 1, A first current collector arranged in contact with one side of the cathode; A first metal-insulator transition portion that is placed in contact with one side of the first current collector and changes from an insulator to a conductor when the temperature rises; a first control unit electrically connected to the first metal-insulator transition region; and A secondary battery comprising a first grounding portion electrically connected to the first control portion.

14. In claim 13, The first metal-insulator transition region is an insulator at a first temperature and changes into a conductor at a second temperature higher than the first temperature to provide a sensing signal to the first control unit. A secondary battery in which the first control unit causes current to flow from the first current collector to the first ground unit in response to the sensing signal.

15. In claim 13, A secondary battery, wherein the first metal-insulator transition region comprises a first vanadium oxide (VO2).

16. In claim 13, A secondary battery further comprising a first thermal conductivity control unit interposed between the first current collector and the first metal-insulator transition unit.

17. In claim 13, A second current collector arranged in contact with one side of the anode; A second metal-insulator transition portion that is placed in contact with one side of the second current collector and changes from an insulator to a conductor when the temperature rises; a second control unit electrically connected to the second metal-insulator transition region; and A secondary battery further comprising a second grounding portion electrically connected to the second control portion.

18. In claim 17, The second metal-insulator transition region is an insulator at a first temperature and changes into a conductor at a second temperature higher than the first temperature to provide a sensing signal to the second control region. A secondary battery in which the second control unit causes current to flow from the second current collector to the second ground unit in response to the sensing signal.

19. In claim 17, A secondary battery, wherein the second metal-insulator transition region comprises a first vanadium oxide (VO2).

20. In claim 17, A secondary battery further comprising a second thermal conductivity control unit interposed between the second current collector and the second metal-insulator transition unit.

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