Battery and battery operation method

Abstract

The invention provides a battery and a battery operation method, the battery comprises a laminated cell formed by alternately stacking first pole pieces and second pole pieces, and a diaphragm is arranged between the adjacent first pole piece and second pole piece; the first pole piece comprises a first current collector and a first active material layer positioned on at least one side of the first current collector, and the second pole piece comprises a second current collector and a second active material layer positioned on at least one side of the second current collector; the first pole piece comprises a first soft tab connected with the first current collector, and the second pole piece comprises a second soft tab connected with the second current collector; the laminated cell further comprises a third pole piece, and the third pole piece comprises a third current collector and at least two third soft tabs connected with the third current collector. Therefore, when the battery is charged at low temperature, lithium precipitation of the battery can be slowed down, so that the internal resistance of the battery is prevented from being increased, the cycle life of the battery is prolonged, and the quick-charge capacity is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery and a battery operation method. Background Art

[0002] In the field of batteries, especially lithium-ion batteries, due to their high energy density and good charge and discharge cycle capabilities, they have been widely used in mobile phones, laptops, electric vehicles and other fields. However, charging lithium-ion batteries at low temperatures will cause lithium deposition at the negative electrode of lithium-ion batteries. Lithium deposition in lithium-ion batteries will increase the internal resistance of the battery, shorten the cycle life, and limit the fast charging capacity.

[0003] In addition, the safety issues caused by battery thermal runaway are mainly because when the battery is under high load such as high power and high current or when the battery is used in a relatively harsh environment such as high temperature, a large amount of heat is often generated inside the battery, and the battery temperature rises further. When the battery temperature rise cannot be suppressed or eliminated, the chemical system inside the battery will further deteriorate, and the internal materials will be destroyed, resulting in thermal runaway, which will cause battery fires, explosions and other accidents. Among them, the higher the pass rate of the battery in the hot box test, the better the safety performance of the battery. Summary of the invention

[0004] In view of this, the present application provides a battery that solves the problems of increased internal resistance, shortened cycle life, and limited fast charging capacity caused by charging the battery at low temperatures. The present application also provides a battery operation method applicable to the above-mentioned battery.

[0005] In order to achieve the above objectives, this application provides the following technical solutions:

[0006] A battery comprises a laminated battery cell formed by alternately stacking first pole pieces and second pole pieces, and a diaphragm is arranged between adjacent first pole pieces and second pole pieces;

[0007] The first pole piece includes a first current collector and a first active material layer located on at least one side of the first current collector, and the second pole piece includes a second current collector and a second active material layer located on at least one side of the second current collector;

[0008] The first pole piece includes a first soft pole ear connected to the first current collector, and the second pole piece includes a second soft pole ear connected to the second current collector;

[0009] The laminated battery core further includes a third pole piece, and the third pole piece includes a third current collector and at least two third soft pole tabs connected to the third current collector.

[0010] Optionally, the third pole piece has the same polarity as the first pole piece, or the third pole piece has the same polarity as the second pole piece.

[0011] Optionally, the third pole piece has the same polarity as the first pole piece, all the first soft pole ears and one third soft pole ear of each third pole piece are welded to form a first hard pole ear, all the second soft pole ears are welded to form a second hard pole ear, and another third soft pole ear of each third pole piece is welded to form a third hard pole ear, the third hard pole ear and the second hard pole ear are connected via a connecting branch, and a switching piece for controlling the opening and closing of the connecting branch is provided on the connecting branch.

[0012] Optionally, the first hard pole tab and the third hard pole tab are positive pole tabs, and the second hard pole tab is a negative pole tab.

[0013] Optionally, the resistivity of the third current collector is 8*10 -7 ~1*10 -5 Ω·m.

[0014] Optionally, the third current collector is a metal current collector, an alloy current collector or a composite current collector.

[0015] Optional,

[0016] The third current collector is made of stainless steel, nickel-chromium alloy foil, iron-nickel alloy foil, iron-chromium-aluminum alloy, aluminum-nickel-iron alloy, or carbon paper; or

[0017] The third current collector is a metal foil plated on the surface of a polymer; or,

[0018] The composite current collector includes an aluminum foil and an oxide layer arranged on both sides of the aluminum foil, wherein the oxide layer is one or more of aluminum oxide, zirconium oxide, boron oxide, titanium oxide, nickel oxide, zinc oxide, gallium oxide, cerium oxide, tin oxide, antimony oxide, boron nitride, magnesium nitride, gallium nitride, and potassium nitride.

[0019] Optionally, the switch comprises a normally open temperature switch and a normally closed temperature switch arranged in series, wherein:

[0020] The normally open temperature switch is closed at a first temperature T1, the normally closed temperature switch is opened at a second temperature T2, and the normally closed temperature switch is closed when at a third temperature T3, wherein: T1, T2 and T3 satisfy: T2>T3>T1.

[0021] Optional,

[0022] T1 satisfies: 70℃≤T1≤90℃; and / or,

[0023] T2 satisfies: 130℃≤T2≤180℃; and / or,

[0024] T3 satisfies: 100℃≤T3<130℃.

[0025] Optionally, the normally open temperature switch is disconnected at a fourth temperature T4, wherein T4 satisfies: T4≤50°C.

[0026] Optionally, in the stacking direction of the laminated battery core, the third pole piece is located at the end of the laminated battery core.

[0027] Optionally, a third active material layer is disposed on a side of the third current collector close to the middle of the laminated battery core, and the third active material layer is not disposed on a side of the third current collector away from the middle of the laminated battery core.

[0028] Optionally, the first hard pole tab, the second hard pole tab and the third hard pole tab are arranged on the same side of the laminated battery core, and in the width direction of the battery, the second hard pole tab is arranged between the first hard pole tab and the third hard pole tab.

[0029] Optionally, the first hard pole tab and the second hard pole tab are arranged on the same side of the laminated battery core, and the first hard pole tab and the third hard pole tab are respectively arranged on different sides of the laminated battery core.

[0030] Optional,

[0031] A first insulating layer is disposed in the end region of the first soft electrode tab close to the first current collector, and in the length direction of the first electrode sheet, the size of the first insulating layer is D, where D satisfies: 0.5 mm ≤ D ≤ 2 mm;

[0032] A second insulating layer is disposed in the end region of the second soft pole ear close to the second current collector, and the size of the second insulating layer in the length direction of the second pole piece is E, where E satisfies: 0.5 mm ≤ E ≤ 2 mm;

[0033] A third insulating layer is disposed in the end region of the third soft electrode tab close to the third current collector, and a size of the third insulating layer in the length direction of the third electrode sheet is F, wherein F satisfies: 0.5 mm ≤ E ≤ 2 mm.

[0034] Optionally, a temperature sensor for detecting the temperature of the battery is disposed on the surface of the battery.

[0035] A battery operation method, applicable to any of the above batteries, the battery operation method comprising a battery charging step and a battery discharging step, the battery charging step at least comprising the following steps:

[0036] S101: Before charging the battery, detecting the temperature of the battery;

[0037] S102: If the battery reaches the target temperature, charging the battery;

[0038] S103: If the battery has not reached the target temperature, the positive and negative electrodes of the external power source are respectively connected to the two tabs of the battery with the same polarity, and after the battery is heated to the target temperature, the positive and negative electrodes of the external power source are respectively connected to the two tabs of the battery with different polarities to charge the battery.

[0039] Optionally, the battery discharging step includes at least the following steps:

[0040] S201: During the battery discharging process, the switch component controls the connection branch circuit according to the temperature of the switch component;

[0041] S202: When the temperature of the switch is at a first temperature, the switch controls the connection branch to be connected;

[0042] S203: When the temperature of the switch element rises from the first temperature to the second temperature, the switch element controls the connection branch to be disconnected;

[0043] S204: When the temperature of the switch component drops from the second temperature to a third temperature, the switch component controls the connection branch to be connected;

[0044] S205: Repeat S203 and S204 according to the temperature of the battery.

[0045] The battery provided by the present application is provided with at least two third soft pole ears on the basis of providing the first soft pole ear and the second soft pole ear, and the third soft pole ear has the same polarity as one of the first soft pole ear and the second soft pole ear, so that at least three hard pole ears are formed, that is, two hard pole ears with the same polarity and one hard pole ear with a different polarity, so that in the initial stage of charging the battery, when the battery temperature is low, the positive and negative poles of the external power supply are respectively connected to the two pole ears with the same polarity of the battery, at this time, the pole ears with the same polarity act as resistors, and the resistors will heat up and the temperature of the battery will rise under the action of the external power supply, and then the positive and negative poles of the external power supply are respectively connected to the two pole ears with different polarities of the battery to realize charging of the battery. With such a configuration, when the battery is charged at a low temperature, the lithium precipitation of the battery can be slowed down to avoid the increase of the internal resistance of the battery, improve the cycle life of the battery, and improve the fast charging capacity.

[0046] The battery provided in the present application realizes self-discharge at high temperature and reduces battery energy by setting a connecting branch between the second hard pole ear and the third hard pole ear, and setting a switching piece on the connecting branch to control the on-off of the connecting branch, so as to reduce the risk of fire of the battery at high temperature, thereby improving the safety performance of the battery during use and improving the pass rate of the battery in the hot box test. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0048] Figure 1 A schematic diagram of a battery structure in an implementation manner provided in this embodiment;

[0049] Figure 2 is a schematic structural diagram of a first pole piece in one implementation manner;

[0050] Figure 3 is a schematic diagram of a battery structure in another embodiment;

[0051] Figure 4 is a schematic structural diagram of a first pole piece in another implementation manner;

[0052] Figure 5 is a schematic diagram of a battery structure in yet another embodiment;

[0053] Figure 6 is a schematic structural diagram of a first pole piece in yet another implementation manner;

[0054] Figure 7 Schematic diagram of the battery cell structure in the first embodiment;

[0055] Figure 8 is a schematic diagram of a battery cell structure in a second embodiment;

[0056] Fig. 9 Schematic diagram of the battery cell structure in the third embodiment.

[0057] exist Figure 1-Figure 9 middle:

[0058] 1-battery core, 2-first hard pole ear, 3-second hard pole ear, 4-connecting branch, 5-on / off piece, 6-third hard pole ear;

[0059] 11-first pole piece, 12-second pole piece, 13-diaphragm, 14-third pole piece, 51-normally open temperature switch, 52-normally closed temperature switch;

[0060] 111 - first current collector, 112 - first active material layer, 113 - first soft electrode tab, 121 - second current collector, 122 - second active material layer, 123 - second soft electrode tab, 141 - third current collector, 142 - third active material layer, 143 - third soft electrode tab. DETAILED DESCRIPTION

[0061] The present application provides a battery and a battery operation method applicable to the battery.

[0062] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0063] like Figures 1 to 9 As shown, the embodiment of the present application provides a battery, wherein the battery can be a lithium-ion battery, a nickel-hydrogen battery, a lead-acid battery, etc. The battery includes a laminated cell 1 formed by alternately stacking a first pole piece 11 and a second pole piece 12, and a diaphragm 13 is arranged between adjacent first pole pieces 11 and second pole pieces 12; the first pole piece 11 includes a first current collector 111 and a first active material layer 112 located on at least one side of the first current collector 111, and the second pole piece 12 includes a second current collector 121 and a second active material layer 122 located on at least one side of the second current collector 121; the first pole piece 11 includes a first soft pole ear 113 connected to the first current collector 111, and the second pole piece 12 includes a second soft pole ear 123 connected to the second current collector 121; the laminated cell 1 also includes a third pole piece 14, and the third pole piece 14 includes a third current collector 141 and at least two third soft pole ears 143 connected to the third current collector 141.

[0064] In this embodiment, an optional implementation is provided, in which the first soft pole tabs 113 in all the first pole pieces 11 and one third soft pole tab 143 of each third pole piece 14 are welded into a first hard pole tab 2, the second soft pole tabs 123 in all the second pole pieces 12 are welded into a second hard pole tab 3, and another third soft pole tab 143 of each third pole piece 14 is welded into a third hard pole tab 6. It should be noted that in this embodiment, the polarity of the first pole piece 11 and the third pole piece 14 are the same.

[0065] In this embodiment, another optional implementation is provided, in which the second soft pole tabs 123 in all the second pole pieces 12 and one third soft pole tab 143 of each third pole piece 14 are welded into a second hard pole tab 3, the first soft pole tabs 113 in all the first pole pieces 11 are welded into a first hard pole tab 2, and another third soft pole tab 143 of each third pole piece 14 is welded into a third hard pole tab 6. It should be noted that in this embodiment, the second pole piece 12 and the third pole piece 14 have the same polarity.

[0066] In this embodiment, another optional implementation is also provided. On the basis of the above embodiment, a fourth pole piece (not shown in the figure) is further provided. The fourth pole piece includes a fourth current collector and at least two fourth soft pole ears connected to the fourth current collector. Further, the first soft pole ears 113 in all the first pole pieces 11 and a third soft pole ear 143 of each third pole piece 14 are welded into a first hard pole ear 2, the second soft pole ears 123 in all the second pole pieces 12 and a fourth soft pole ear of each fourth pole piece are welded into a second hard pole ear 3, another third soft pole ear 143 of each third pole piece 14 is welded into a third hard pole ear 6, and another fourth soft pole ear of each fourth pole piece is welded into a fourth hard pole ear. It should be noted that in this embodiment, the polarity of the first pole piece 11 and the third pole piece 14 is the same, and the polarity of the second pole piece 12 and the fourth pole piece is the same.

[0067] Here, through the above arrangement, at least three hard pole ears are arranged, and two of the at least three hard pole ears have the same polarity, and the other hard pole ear has a different polarity from the above two hard pole ears. With such arrangement, in the initial stage of charging the battery, when the battery temperature is low, the positive and negative electrodes of the external power source are respectively connected to the two hard pole ears of the battery with the same polarity. At this time, the third current collector connected between the two hard pole ears with the same polarity acts as a resistor. Under the action of the external power source, the resistor will generate heat and rise in temperature to increase the temperature of the battery. When it rises to a suitable temperature, the positive and negative electrodes of the external power source are respectively connected to the two hard pole ears of the battery with different polarities to realize charging of the battery. With such arrangement, when the battery is charged at a low temperature, the lithium deposition of the battery can be slowed down to avoid the increase of the internal resistance of the battery, improve the cycle life of the battery, and improve the fast charging capacity.

[0068] It should be noted that the third pole piece 14 has the same polarity as the first pole piece 11 or the second pole piece 12, wherein when the third pole piece 14 and the first pole piece 11 have the same polarity, the third pole piece 14 is disposed between adjacent second pole pieces 12, or the third pole piece 14 is disposed adjacent to the second pole piece 12; when the third pole piece 14 and the second pole piece 12 have the same polarity, the third pole piece 14 is disposed between adjacent first pole pieces 11, or the third pole piece 14 is disposed adjacent to the first pole piece 11. The first pole piece 11, the second pole piece 12 and the third pole piece 14 are stacked to form a laminated battery cell 1.

[0069] It should also be noted that the number of third soft pole ears 143 in the third pole piece 14 is not limited here, and two or more third soft pole ears 143 can be provided. Correspondingly, the number of fourth soft pole ears in the fourth pole piece is not limited, and two or more fourth soft pole ears can also be provided. Also, the number of third pole pieces 14 is not limited here, and one or more third pole pieces 14 can be provided.

[0070] It should also be noted that the first pole piece 11 and the second pole piece 12 are not limited here. The first pole piece can be a positive pole piece, and the second pole piece 12 is a negative pole piece. Of course, the first pole piece 11 can also be a negative pole piece, and the second pole piece 12 is a positive pole piece.

[0071] The battery of the above structure is provided with at least two third soft pole ears 143 on the basis of providing the first soft pole ear 113 and the second soft pole ear 123, and the third soft pole ear 143 has the same polarity as one of the first soft pole ear 113 and the second soft pole ear 123, so that at least three hard pole ears are formed, that is, two hard pole ears with the same polarity and one hard pole ear with a different polarity. In this way, in the initial stage of charging the battery, when the battery temperature is low, the positive and negative poles of the external power supply are respectively connected to the two pole ears with the same polarity of the battery. At this time, the pole ears with the same polarity act as resistors. Under the action of the external power supply, the resistor will heat up and the temperature of the battery will rise. When it rises to a suitable temperature, the positive and negative poles of the external power supply are respectively connected to the two pole ears with different polarities of the battery to realize charging of the battery. With such a configuration, when the battery is charged at a low temperature, the lithium deposition of the battery can be slowed down to avoid the increase of the internal resistance of the battery, improve the cycle life of the battery, and improve the fast charging capacity.

[0072] In some embodiments, the third pole piece 14 has the same polarity as the first pole piece 11, or the third pole piece 14 has the same polarity as the second pole piece 12. That is, when the first pole piece 11 is a positive pole piece, the third pole piece 14 is a positive pole piece, and the second pole piece 12 is a negative pole piece; when the first pole piece 11 is a negative pole piece, the third pole piece 14 is a negative pole piece, and the second pole piece 12 is a positive pole piece.

[0073] In some embodiments, the third pole piece 14 has the same polarity as the first pole piece 11, all the first soft pole ears 113 and one third soft pole ear 143 of each third pole piece 14 are welded into a first hard pole ear 2, all the second soft pole ears 123 are welded into a second hard pole ear 3, and another third soft pole ear 143 of each third pole piece 14 is welded into a third hard pole ear 6, and the third hard pole ear 6 and the second hard pole ear 3 are connected through a connecting branch 4, and a switching piece 5 for controlling the connection branch 4 to be turned on and off is provided on the connecting branch 4.

[0074] In this embodiment, an optional implementation is provided, in which the switch 5 is composed of a temperature switch. Furthermore, the temperature switch is a normally open temperature switch 51 and a normally closed temperature switch 52 arranged in series. Under normal temperature conditions, that is, when the battery is in normal use, the normally open temperature switch 51 is in an open state, and the normally closed temperature switch 52 is in a closed state. When the battery is under high loads such as high power and high current, or when the battery is used in a relatively harsh environment such as high temperature, the temperature of the battery will continue to rise, and the temperature rise of the normally open temperature switch 51 will cause the normally open temperature switch 51 to close. Since the normally closed temperature switch 52 is in a closed state, the connecting branch 4 connected between the second hard pole ear 3 and the third hard pole ear 6 is connected at this time, and the battery is self-discharged, thereby reducing the voltage and capacity of the battery, avoiding further deterioration of the battery caused by the temperature rise of the battery, avoiding thermal runaway of the battery, and improving the safety of the battery when in use. When the normally open temperature switch 51 is in the closed state, the temperature of the connecting branch 4 will continue to rise, and the normally closed temperature switch 52 will be disconnected after reaching a certain temperature, so that the connecting branch 4 is disconnected, avoiding the connecting branch 4 from continuing to heat up and preventing the connecting branch 4 from being melted, and the battery works normally at this time; when the temperature of the switching element 5 drops to a certain temperature, the normally closed temperature switch 52 will be closed again, so that the battery can be protected again, and pulse discharge can be achieved as the temperature changes, which can better protect the battery and improve the safety of the battery during use.

[0075] In this embodiment, another optional implementation is also provided, the switch 5 is composed of a temperature sensor, a switch and a control module, wherein the temperature sensor is communicatively connected with the control module, the switch is electrically connected with the control module, wherein the battery is in a normal working state and the switch is in a disconnected state. When the battery is under high load such as high power and high current or the battery is used in a relatively harsh environment such as high temperature, the temperature of the battery will continue to rise. As the temperature of the battery rises, the temperature of the temperature sensor will also rise. The temperature sensor transmits the temperature information to the control module, and the control module controls the switch to close according to the received temperature information. At this time, the connecting branch 4 connected between the second hard pole ear 3 and the third hard pole ear 6 is connected, and the battery self-discharges, thereby reducing the voltage and capacity of the battery, avoiding further deterioration of the battery caused by the battery temperature rise, avoiding thermal runaway of the battery, and improving the safety of the battery when in use. The control module receives the temperature information detected by the temperature sensor in real time. When the temperature rises high when the switch is in a closed state, the control module controls the switch to open, so that the connecting branch 4 is disconnected, and the connecting branch 4 is prevented from being fused. When the temperature detected by the temperature sensor drops, the control module controls the switch to close again, so that the battery can be protected again. As the temperature changes, pulse discharge can be achieved, which can better protect the battery and improve the safety of the battery during use.

[0076] It should be noted that the connecting branch 4 is a conductive branch, which is used to achieve electrical connection between the second hard pole tab 3 and the third hard pole tab 6 .

[0077] The battery of the above structure is provided with a switch 5 on the connecting branch 4 between the second hard pole ear 3 and the third hard pole ear 6 of the battery cell 1, and the switch 5 can control the opening and closing of the connecting branch 4. The switch 5 controls the connection of the connecting branch 4 to reduce the voltage and capacity of the battery, thereby avoiding further deterioration of the battery caused by the temperature rise of the battery, avoiding thermal runaway of the battery, and improving the safety of the battery when in use. Moreover, after the battery voltage is reduced, the connecting branch 4 can also be controlled to be disconnected by the switch 5 to enable the battery to work and use normally.

[0078] In some embodiments, the first hard pole ear 2 and the third hard pole ear 6 are positive pole ears, and the second hard pole ear 3 is a negative pole ear. That is to say, the first current collector 111 and the third current collector 141 are positive current collectors, and the second current collector 121 is a negative current collector. In this way, when the battery is charged at the initial stage and the battery temperature is low, the positive and negative electrodes of the external power supply are connected to the first hard pole ear 2 and the third hard pole ear 6 respectively, and the current flows through the first hard pole ear 2, the third current collector 141 and the third hard pole ear 6 in sequence. At this time, the third current collector 141 acts as a resistor, and heat is generated when the current passes through, thereby increasing the temperature of the battery to alleviate the lithium precipitation of the battery when charging at low temperature.

[0079] In addition, the first hard pole tab 2 , the second hard pole tab 3 and the third hard pole tab 6 may also be arranged in other ways, for example: the first hard pole tab 2 and the third hard pole tab 6 are negative pole tabs, and the second hard pole tab 3 is a positive pole tab.

[0080] On the basis of the above embodiment, further, the resistivity of the third current collector 141 is 8*10 -7 ~1*10 -5 Ω·mm. In the initial stage of charging the battery composed of the above-mentioned first pole piece 11, the second pole piece 12 and the third pole piece 14, the positive and negative poles of the external power supply are respectively connected to the first hard pole ear 2 and the third hard pole ear 6. At this time, the third current collector 141 generates heat as a resistor. In this way, heat is generated under the action of the external circuit current, thereby improving the heating efficiency of the battery to reduce lithium deposition in the battery during subsequent charging. Here, the resistivity of the third current collector 141 is ensured to be within the above range, which can improve the heating efficiency of the third current collector 141 as a resistor, thereby improving the efficiency of heating the battery from a low temperature to a suitable charging temperature, thereby improving the charging efficiency of the battery, and avoiding the melting of the current collector or the pole ear caused by excessive resistivity. Normally, the resistivity of the first current collector 111 and the second current collector 121 is less than 8*10 -7That is to say, the resistance of the first current collector 111 and the second current collector 121 is ensured to be less than the resistance of the third current collector 141, so that during the battery charging and discharging process, the impedance of the battery can be reduced and the energy loss can be reduced.

[0081] For example, the resistivity of the third current collector 141 may be: 8*10 -7 Ω·m、8.1*10 -7 Ω·m、8.5*10 -7 Ω·m、9*10 -7 Ω·m, 1*10 -6 Ω·m、2*10 -6 Ω·m、5*10 -6 Ω·m、8*10 -6 Ω·m、9*10 -6 Ω·m、9.5*10 -6 Ω·m, 1*10 -5 Ω·m, etc.

[0082] In addition, when a fourth electrode is provided with the second electrode 12, the resistivity of the fourth current collector may also be 8*10 -7 ~1*10 -5 Ω·m, which can also achieve the temperature increase of the battery in the early stage of battery charging.

[0083] In some embodiments, the third current collector 141 is a metal current collector, an alloy current collector or a composite current collector. In other words, the material of the third current collector 141 is not limited here, as long as the resistivity of the third current collector 141 is within 8*10 -7 ~1*10 -5 It can be within the range of Ω·mm. Such setting can improve the heating efficiency of the battery in the initial stage of charging.

[0084] Further, in some embodiments, when the third current collector 141 is a metal current collector, the third current collector 141 may be a metal such as aluminum; when the third current collector 141 is an alloy current collector, the third current collector 141 may be stainless steel, nickel-chromium alloy foil, iron-nickel alloy foil, iron-chromium-aluminum alloy, aluminum-nickel-iron alloy, etc.; when the third current collector 141 is a composite current collector, the third current collector 141 includes aluminum foil and an oxide layer disposed on both sides of the aluminum foil, and the oxide layer is one or more of aluminum oxide, zirconium oxide, boron oxide, titanium oxide, nickel oxide, zinc oxide, gallium oxide, cerium oxide, tin oxide, antimony oxide, boron nitride, magnesium nitride, gallium nitride, and potassium nitride. The third current collector 141 may also be an aluminum foil on a polymer surface (a sandwich structure conforming to an aluminum layer on a PET film surface), the metal oxide layer is formed on both sides of the aluminum foil, and the active material layer is formed on the metal oxide layer on one side.

[0085] In addition, the first electrode current collector may also be carbon paper or the like.

[0086] In some embodiments, the switch 5 includes a normally open temperature switch 51 and a normally closed temperature switch 52 which are arranged in series, wherein: the normally open temperature switch 51 is closed when it is at a first temperature T1, the normally closed temperature switch 52 is opened when it is at a second temperature T2, and the normally closed temperature switch 52 is closed when it is at a third temperature T3, wherein: T1, T2 and T3 satisfy: T2>T3>T1. Specifically, when the battery is working normally, the normally open temperature switch 51 is in an open state and the normally closed temperature switch 52 is in a closed state, and when the battery is under high load such as high power and high current or the battery is used in a relatively harsh environment such as high temperature, the temperature of the battery will continue to rise, and the temperature of the normally open temperature switch 51 will also rise. When the normally open temperature switch 51 is at temperature T1, the normally open temperature switch 51 is closed, and the normally closed temperature switch 52 itself is in a closed state. At this time, the two switches connected in series on the connecting branch 4 are both in a closed state, and the connecting branch 4 is turned on, then the voltage and capacity of the battery will decrease; Since the connecting branch 4 is in the conducting state, the temperature of the normally closed temperature switch 52 will continue to rise. When the temperature of the normally closed temperature switch 52 is at the temperature T2, the normally closed temperature switch 52 will be in the disconnected state. At this time, the connecting branch 4 is in the disconnected state, and the number of normally closed temperature switches 52 on the connecting branch 4 will decrease. When the temperature of the normally closed temperature switch 52 drops to the temperature T3, the normally closed temperature switch 52 will be closed again. At this time, the connecting branch 4 will be turned on again. When the battery continues to work, the normally closed temperature switch 52 will repeat the above process, thereby realizing the pulse discharge of the battery. To ensure the safety of the battery during use.

[0087] It should be noted that the number of normally open temperature switches 51 and normally closed temperature switches 52 is not limited here, and one or more of each can be provided.

[0088] In addition, by providing the normally open temperature switch 51 and the normally closed temperature switch 52, the safety performance of the battery can be improved without affecting the chemical system. This is applicable to various types of batteries and has little effect on the energy density of the battery.

[0089] It should also be noted that the connection method between the normally open temperature switch 51 and the normally closed temperature switch 52 and the second hard pole ear 3 and the third hard pole ear 6 is limited. For example, the electrical connection can be achieved by connecting with a wire, by welding methods such as soldering, resistance welding, laser welding, etc., or by bonding with electrical adhesive.

[0090] It should also be noted that the normally open temperature switch 51, the normally closed temperature switch 52 and the connecting branch 4 can be located inside the battery or outside the battery, and can also be connected between the poles of different polarities in the PACK or PCM protection board circuit.

[0091] In some embodiments, T1 satisfies: 70° C. ≤ T1 ≤ 90° C. For example, T1 may be 70° C., 71° C., 72° C., 75° C., 80° C., 82° C., 85° C., 88° C., 89° C., 90° C., and the like.

[0092] In some embodiments, T2 satisfies: 130° C. ≤ T2 ≤ 180° C. For example, T2 may be 130° C., 131° C., 132° C., 135° C., 140° C., 150° C., 160° C., 170° C., 175° C., 177° C., 179° C., 180° C., and the like.

[0093] In some embodiments, T3 satisfies: 100° C. ≤ T3 < 130° C. For example, T3 may be 100° C., 101° C., 102° C., 105° C., 110° C., 115° C., 120° C., 125° C., 127° C., 129° C., and the like.

[0094] Here, ensuring that T1, T2 and T3 are within the above range can more flexibly control the battery discharge voltage and capacity, better avoid further deterioration of the battery caused by battery temperature rise, avoid thermal runaway of the battery, and improve the safety of the battery during use.

[0095] In some embodiments, the normally open temperature switch 51 is disconnected when the temperature is at the fourth temperature T4. Based on the operation of the normally open temperature switch 51 and the normally closed temperature switch 52, when the battery stops working, the temperature of the normally open temperature switch 51 and the normally closed temperature switch 52 will gradually decrease. When the temperature decreases to the temperature T4, the normally open temperature switch 51 in the closed state will be disconnected, so that the connecting branch 4 will be disconnected, so that the normally open temperature switch 51 will be disconnected when the battery is used next time, so that the normally open temperature switch 51 and the normally closed temperature switch 52 set on the connecting branch 4 will return to the initial state, so that the switch 5 can still protect the battery from thermal runaway when the battery is used subsequently.

[0096] Wherein T4 satisfies: T4≤50° C. For example, T4 may be 50° C., 49° C., 45° C., 42° C., 40° C., 35° C., 30° C., 25° C., and the like.

[0097] In some embodiments, in the stacking direction of the laminated battery core 1, the third pole piece 14 is located at the end of the laminated battery core 1. Specifically, the first hard pole ear 2 and the third hard pole ear 6 are positive pole ears, and the second hard pole ear 3 is a negative pole ear. Under normal circumstances, the third current collector 141 located at the end of the laminated battery core 1 is only coated with an active material layer on one side. Since the resistance of the third current collector 141 is greater than the resistance of the first current collector 111 and the second current collector 121, the third current collector 141 is connected to at least two third soft pole ears 143. In this way, when the battery provided with the above-mentioned current collector is discharged, compared with the third current collector 141 being arranged in the middle of the stacking direction of the laminated battery core 1, the increase in the impedance of the battery can be reduced, thereby ensuring the performance of the battery.

[0098] It should be noted that the stacking direction of the laminated battery cell 1 refers to Figure 7 The direction is indicated by the double-headed arrow Z.

[0099] Furthermore, in one embodiment, the third active material layer 142 is disposed on the side of the third current collector 141 close to the middle of the laminated battery core 1, and the third active material layer 142 is not disposed on the side of the third current collector 141 away from the middle of the laminated battery core 1. In other words, the third active material layer 142 is disposed on only one side of the third current collector 141, and the side on which the third active material layer 142 is disposed is the side close to the center of the laminated battery core 1. In this configuration, since the resistivity of the third current collector 141 is between 8*10 -7 ~1*10 -5 Ω·m range, at this time, the battery composed of the first electrode sheet 11, the second electrode sheet 12 and the third electrode sheet 14 is provided with the third active material layer 142 only on one side of the third current collector 141, which can further reduce the increase of the impedance of the battery, thereby further improving the performance of the battery.

[0100] In addition, in the stacking direction of the laminated battery core 1 , the third current collector 141 may also be located in the middle of the laminated battery core 1 , so that the problem of lithium deposition at low battery temperature in the initial stage of battery charging can be solved.

[0101] On the basis of the above embodiment, further, in the stacking direction of the laminated battery core 1, the pole pieces at both ends of the laminated battery core 1 are the third pole pieces 14, and the first pole piece 11 and the third pole piece 14 are both positive pole pieces. In this way, the heating efficiency of the battery is further improved.

[0102] It should be noted that the stacking direction of the battery cell 1 refers to Figure 7 The direction is indicated by the double-headed arrow Z.

[0103] It should also be noted that the number of third pole pieces 14 is not limited herein, and one or more third pole pieces 14 may be provided.

[0104] In some embodiments, Figure 1 As shown, the first hard pole ear 2, the second hard pole ear 3 and the third hard pole ear 6 are arranged on the same side of the battery cell 1, and in the width direction of the battery, the second hard pole ear 3 is arranged between the first hard pole ear 2 and the third hard pole ear 6. Specifically, when the battery temperature is low, the positive and negative electrodes of the external power source are connected to the first hard pole ear 2 and the third hard pole ear 6, respectively. When the battery is heated to the target temperature, the positive and negative electrodes of the external power source are connected to the first hard pole ear 2 and the second hard pole ear 3 of the battery, respectively. Here, by arranging the second hard pole ear 3 between the first hard pole ear 2 and the third hard pole ear 6, the convenience of heating and charging the battery can be improved.

[0105] In some embodiments, the first hard tab 2 and the second hard tab 3 are arranged on the same side of the battery cell 1, and the first hard tab 2 and the third hard tab 6 are respectively arranged on different sides of the battery cell 1. Exemplarily, the first hard tab 2 and the third hard tab 6 can be arranged on adjacent sides of the battery cell 1, such as Figure 3 or Figure 5 As shown; the first hard pole ear 2 and the third hard pole ear 6 can also be arranged on the opposite side of the battery cell 1. When the battery temperature is low, the positive and negative electrodes of the external power supply are respectively connected to the first hard pole ear 2 and the third hard pole ear 6 of the battery, and the third current collector 141 of the first hard pole ear 2 and the third hard pole ear 6 will release heat as a resistor, and the size of the resistor is positively correlated with the length of the resistor, that is, the greater the distance between the first hard pole ear 2 and the third hard pole ear 6, the greater the resistance when heating the battery, and the higher the heating efficiency of the battery, such a setting can further improve the heating efficiency of the battery.

[0106] On the basis of the above embodiment, further, the first hard pole ear 2 and the third hard pole ear 6 are respectively arranged at two opposite corners of the battery cell 1, similar to Figure 3 The arrangement positions of the first hard pole ear 2 and the third hard pole ear 6 shown in the figure can further increase the distance between the first hard pole ear 2 and the third hard pole ear 6, and further increase the length of the third current collector 141 when heating the battery, so as to further improve the heating efficiency of the battery.

[0107] In some embodiments, a first insulating layer is provided at an end region of the first soft pole ear 113 near the first current collector 111, and in the length direction of the first pole piece 11, a size of the first insulating layer is D, wherein D satisfies: 0.5mm≤D≤2mm; a second insulating layer is provided at an end region of the second soft pole ear 123 near the second current collector 121, and in the length direction of the second pole piece 1212, a size of the second insulating layer is E, wherein E satisfies: 0.5mm≤E≤2mm; a third insulating layer is provided at an end region of the third soft pole ear 143 near the third current collector 141, and in the length direction of the third pole piece 14, a size of the third insulating layer is F, wherein F satisfies: 0.5mm≤E≤2mm. Typically, the first soft pole ear 113, the second soft pole ear 123 and the third soft pole ear 143 are all formed by die-cutting the first current collector 111 and the second current collector 121. When a plurality of first soft pole ears 113 arranged in the stacking direction of the laminated battery core 1 are welded into the first hard pole ear 2 of the battery, a plurality of second soft pole ears 123 arranged in the stacking direction of the laminated battery core 1 are welded into the second hard pole ear 3 of the battery, and a plurality of third soft pole ears 143 arranged in the stacking direction of the laminated battery core 1 are welded into the third hard pole ear 6 of the battery, the first soft pole ear 113 may contact the second current collector 121, and the second soft pole ear 123 may also contact the third hard pole ear 6 of the battery. The third soft pole ear 143 may also be in contact with the second current collector 121, which may cause a short circuit in the battery. By setting a first insulating layer at the end of the first soft pole ear 113 close to the first current collector 111, setting a second insulating layer at the end of the second soft pole ear 123 close to the second current collector 121, and setting a third insulating layer at the end of the third soft pole ear 143 close to the third current collector 141, the first soft pole ear 113 can be prevented from contacting the second current collector 121, the second soft pole ear 123 can be prevented from contacting the first current collector 111, and the third soft pole ear 143 can be prevented from contacting the second current collector 121, so as to avoid a short circuit in the battery.

[0108] Exemplarily, the size of the first insulating layer can be 0.5mm, 0.55mm, 0.7mm, 0.9mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 1.9mm, 1.95mm, 2mm, etc.; the size of the second insulating layer can be 0.5mm, 0.55mm, 0.7mm, 0.9mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 1.9mm, 1.95mm, 2mm, etc.

[0109] It should be noted that the length direction of the first pole piece 11 and the length direction of the second pole piece 12 are Figure 2 The direction is indicated by the double-headed arrow Y.

[0110] In some embodiments, a temperature sensor for detecting the battery temperature is provided on the surface of the battery. Specifically, by providing the temperature sensor, the battery temperature can be detected, so that when the battery temperature is low at the initial stage of battery charging, the positive and negative electrodes of the external power source are connected to the battery lugs with the same polarity to heat the battery, and the temperature sensor can detect the battery temperature to conveniently monitor the battery temperature, so that when the battery is heated to the target temperature, the positive and negative electrodes of the external power source are connected to the battery lugs with different polarities to conveniently and efficiently charge the battery.

[0111] Taking a battery with two positive electrode tabs and one negative electrode tab to form a three-tab structure battery as an example, the following examples and comparative examples are carried out:

[0112] Example 1

[0113] A battery with a three-pole structure, the battery has two positive pole tabs and one negative pole tab, the positive pole tabs are located on both sides of the negative pole tab. A special positive electrode sheet with two soft pole tabs, the positive electrode current collector is a 5μm thick stainless steel foil, and a positive electrode sheet with a soft pole tab, the positive electrode current collector is an 8um aluminum foil and a negative electrode sheet with a soft pole tab. The positive pole sheet with a single positive pole tab, the separator 13, the single negative pole tab pole sheet, and the separator 13 are sequentially stacked and assembled, and finally the positive pole sheet with two pole tabs is assembled on the upper and lower surfaces of the stacked structure to prepare a battery stack such as Figure 7 As shown, after stacking, the negative soft pole ears overlap in the vertical direction, the positive soft pole ears overlap, and the aluminum pole ears are transferred and welded. After being loaded into the aluminum plastic film shell, the packaging, liquid injection, formation, sorting and other processes are carried out. A 75℃ normally open temperature switch 51 (internal resistance 4mΩ) and a 160℃ normally closed temperature switch 52 (recovery temperature 110℃, internal resistance 4mΩ) are welded between the negative pole ear and the right positive pole ear (soft pole ear transferred to hard pole ear) of the qualified battery. Figure 1 As shown. The welded battery is subjected to hot box test and charging heating test.

[0114] Embodiment 2:

[0115] Double positive soft pole ear, one soft pole ear at the head, one soft pole ear at the bottom of the side. Figure 3 As shown, other designs are the same as those in Example 1.

[0116] Example 3

[0117] Double positive soft pole ear, one soft pole ear is on the head, and one soft pole ear is in the middle of the side. Figure 5 As shown, other designs are the same as those in Example 1.

[0118] Example 4

[0119] The double positive electrode soft ear design uses 5μm stainless steel as the current collector, and the active material layer is coated on both sides of the current collector. The pole piece is placed in the middle of the stack. Figure 8 shown.

[0120] Example 5

[0121] A double positive electrode soft ear design is added to the structure of Example 1, the current collector is made of 5 μm stainless steel, and active material layers are coated on both sides of the current collector, such as Fig. 9 shown.

[0122] Comparative Example 1

[0123] The bipolar lug structure has no third positive lug, no welding temperature switch, and the positive current collector uses 8um aluminum foil. Other designs are the same as those in Example 1.

[0124] Comparative Example 2

[0125] The double-pole ear structure has no third positive electrode ear. A temperature switch is welded between the positive electrode and the negative electrode, and the positive electrode current collector uses 8um aluminum foil. Other designs are the same as those in Example 1.

[0126] Comparative Example 3

[0127] The battery structure is the same as that in Example 1, except that the positive electrode current collector uses 8um aluminum foil, and other materials are the same as those in Example 1.

[0128] Comparative Example 4

[0129] The battery structure is the same as that of Embodiment 1, except that the normally open temperature switch 51 and the normally closed temperature switch 52 are not provided.

[0130] Table 1

[0131]

[0132]

[0133] A battery operating method is applicable to the above-mentioned battery. Since the operating method is applicable to the battery, the beneficial effects brought by the battery operating method are shown in the above-mentioned contents and will not be described in detail here.

[0134] The battery operation method includes a battery charging step and a battery discharging step, and the battery charging step includes at least the following steps: S101: before charging the battery, detecting the temperature of the battery; S102: if the battery reaches the target temperature, charging the battery; S103: if the battery does not reach the target temperature, connecting the positive and negative electrodes of the external power source to two tabs of the battery with the same polarity, respectively, heating the battery to the target temperature, and then connecting the positive and negative electrodes of the external power source to two tabs of the battery with different polarities, respectively, to charge the battery.

[0135] Specifically, before charging the battery, the temperature of the battery is detected by a temperature sensor arranged on the battery; when the battery temperature detected by the temperature sensor reaches the target temperature, the positive and negative electrodes of the external power supply are connected to two pole ears of the battery with different polarities to charge the battery; when the battery temperature detected by the temperature sensor does not reach the target temperature, the positive and negative electrodes of the external power supply are connected to two pole ears of the battery with the same polarity. At this time, the current collector connected to the two pole ears acts as a resistor, so that the temperature of the battery will increase, and the temperature sensor will detect the temperature of the battery in real time. When the battery temperature rises to the target temperature, the positive and negative electrodes of the external power supply are connected to the two pole ears of the battery with different polarities to charge the battery.

[0136] It should be noted that the target temperature refers to the battery being at a suitable charging temperature. At this temperature, less or even no lithium deposition occurs when the battery is charged compared to charging under low temperature conditions.

[0137] In some embodiments, the battery discharging step includes at least the following steps:

[0138] S201: During the discharge process of the battery, the switch 5 controls the connection of the connecting branch 4 according to the temperature of the switch 5; S202: When the temperature of the switch 5 is at the first temperature, the switch 5 controls the connection of the connecting branch 4; S203: When the temperature of the switch 5 rises from the first temperature to the second temperature, the switch 5 controls the connection branch 4 to be disconnected; S204: When the temperature of the switch 5 drops from the second temperature to the third temperature, the switch 5 controls the connection branch 4 to be connected; S205: Repeat S203 and S204 according to the temperature of the battery.

[0139] Specifically, when the battery is discharging, especially when the battery is under high load such as high power and high current or when the battery is used in a relatively harsh environment such as high temperature, a large amount of heat is often generated inside the battery, and the battery temperature further rises. When the temperature rise of the battery causes the temperature of the normally open temperature switch 51 to be at a first temperature, the normally open temperature switch 51 is closed, and the connecting branch 4 connected between the second hard pole ear 3 and the third hard pole ear 6 is turned on. At this time, the battery self-discharges to reduce the battery voltage to avoid thermal runaway and other faults of the battery. When the normally open temperature switch 51 and the normally closed temperature switch 51 are turned on, the battery self-discharges to reduce the battery voltage to avoid thermal runaway and other faults. The temperature switches 52 are all in the closed state. Although the voltage of the external power supply is reduced, the temperature of the connecting branch 4 will continue to rise. When the temperature of the normally closed temperature switch 52 rises to the second temperature, the normally closed temperature switch 52 is disconnected. At this time, the connecting branch 4 is disconnected synchronously. At this time, the external power supply is working normally. Since the connecting branch 4 is not working, the temperature of the normally closed temperature switch 52 will drop. When the temperature of the normally closed temperature switch 52 drops to the third temperature, the normally closed temperature switch 52 will be closed again. At this time, the connecting branch 4 is turned on again, and the battery will self-discharge again, reducing the battery voltage again. During the operation of the battery, when the battery temperature rises, the normally open temperature switch 51 and the normally closed temperature switch 52 will repeat the above process to realize pulse discharge of the battery, and finally realize self-discharge of the battery at high temperature, so as to reduce the battery capacity and improve the battery safety while the battery body will not cause high-temperature thermal runaway.

[0140] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0141] The block diagrams of the devices, apparatuses, equipment, and systems involved in this application are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The words "such as" used here refer to the phrase "such as but not limited to", and can be used interchangeably with them.

[0142] It should also be noted that in the apparatus, device and method of the present application, each component or each step can be decomposed and / or recombined. Such decomposition and / or recombination should be regarded as equivalent solutions of the present application.

[0143] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0144] It should be understood that the qualifiers "first", "second", "third", "fourth", "fifth" and "sixth" used in the description of the embodiments of the present application are only used to more clearly explain the technical solutions and cannot be used to limit the scope of protection of the present application.

[0145] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A battery, characterized in that: A laminated battery cell is formed by alternately stacking first pole pieces and second pole pieces, and a diaphragm is arranged between adjacent first pole pieces and second pole pieces; The first pole piece includes a first current collector and a first active material layer located on at least one side of the first current collector, and the second pole piece includes a second current collector and a second active material layer located on at least one side of the second current collector; The first pole piece includes a first soft pole ear connected to the first current collector, and the second pole piece includes a second soft pole ear connected to the second current collector; The laminated battery core further includes a third pole piece, and the third pole piece includes a third current collector and at least two third soft pole tabs connected to the third current collector.

2. The battery according to claim 1, characterized in that The third pole piece has the same polarity as the first pole piece, or the third pole piece has the same polarity as the second pole piece.

3. The battery according to claim 1 or 2, characterized in that: The third pole piece has the same polarity as the first pole piece, all the first soft pole ears and one third soft pole ear of each third pole piece are welded into a first hard pole ear, all the second soft pole ears are welded into a second hard pole ear, and another third soft pole ear of each third pole piece is welded into a third hard pole ear, and the third hard pole ear and the second hard pole ear are connected by a connecting branch, and a switching piece for controlling the opening and closing of the connecting branch is provided on the connecting branch.

4. The battery according to claim 3, characterized in that The first hard pole tab and the third hard pole tab are positive pole tabs, and the second hard pole tab is a negative pole tab.

5. The battery according to claim 3, characterized in that The resistivity of the third current collector is 8*10 -7 ~1*10 -5 Ω·m.

6. The battery according to claim 5, characterized in that The third current collector is a metal current collector, an alloy current collector or a composite current collector.

7. The battery according to claim 6, characterized in that The third current collector is made of stainless steel, nickel-chromium alloy foil, iron-nickel alloy foil, iron-chromium-aluminum alloy, aluminum-nickel-iron alloy, or carbon paper; or The third current collector is a metal foil plated on the surface of a polymer; or, The composite current collector includes an aluminum foil and an oxide layer arranged on both sides of the aluminum foil, wherein the oxide layer is one or more of aluminum oxide, zirconium oxide, boron oxide, titanium oxide, nickel oxide, zinc oxide, gallium oxide, cerium oxide, tin oxide, antimony oxide, boron nitride, magnesium nitride, gallium nitride, and potassium nitride.

8. The battery according to claim 3, characterized in that The switch comprises a normally open temperature switch and a normally closed temperature switch arranged in series, wherein: The normally open temperature switch is closed at a first temperature T1, the normally closed temperature switch is opened at a second temperature T2, and the normally closed temperature switch is closed when at a third temperature T3, wherein: T1, T2 and T3 satisfy: T2>T3>T1.

9. The battery according to claim 8, characterized in that T1 satisfies: 70℃≤T1≤90℃; and / or, T2 satisfies: 130℃≤T2≤180℃; and / or, T3 satisfies: 100℃≤T3<130℃.

10. The battery according to claim 8, characterized in that The normally open temperature switch is disconnected at a fourth temperature T4, wherein T4 satisfies: T4≤50°C.

11. The battery according to claim 5, characterized in that In the stacking direction of the laminated battery core, the third pole piece is located at the end of the laminated battery core.

12. The battery according to claim 11, characterized in that A third active material layer is disposed on a side of the third current collector close to the middle of the laminated battery core, and no third active material layer is disposed on a side of the third current collector away from the middle of the laminated battery core.

13. The battery according to claim 3, characterized in that The first hard pole tab, the second hard pole tab and the third hard pole tab are arranged on the same side of the laminated battery core, and in the width direction of the battery, the second hard pole tab is arranged between the first hard pole tab and the third hard pole tab.

14. The battery according to claim 3, characterized in that The first hard pole tab and the second hard pole tab are arranged on the same side of the laminated battery core, and the first hard pole tab and the third hard pole tab are respectively arranged on different sides of the laminated battery core.

15. The battery according to claim 1, characterized in that A first insulating layer is disposed in the end region of the first soft electrode tab close to the first current collector, and in the length direction of the first electrode sheet, the size of the first insulating layer is D, where D satisfies: 0.5 mm ≤ D ≤ 2 mm; A second insulating layer is disposed in the end region of the second soft pole ear close to the second current collector, and the size of the second insulating layer in the length direction of the second pole piece is E, where E satisfies: 0.5 mm ≤ E ≤ 2 mm; A third insulating layer is disposed in the end region of the third soft electrode tab close to the third current collector, and a size of the third insulating layer in the length direction of the third electrode sheet is F, wherein F satisfies: 0.5 mm ≤ E ≤ 2 mm.

16. The battery according to claim 1, characterized in that A temperature sensor for detecting the temperature of the battery is arranged on the surface of the battery.

17. A battery operation method, characterized in that: Applicable to the battery according to any one of claims 1 to 16, the battery operation method comprises a battery charging step and a battery discharging step, and the battery charging step comprises at least the following steps: S101: Before charging the battery, detecting the temperature of the battery; S102: If the battery reaches the target temperature, charging the battery; S103: If the battery has not reached the target temperature, the positive and negative electrodes of the external power source are respectively connected to the two tabs of the battery with the same polarity, and after the battery is heated to the target temperature, the positive and negative electrodes of the external power source are respectively connected to the two tabs of the battery with different polarities to charge the battery.

18. The battery operation method according to claim 17, characterized in that: The battery discharging step comprises at least the following steps: S201: During the battery discharging process, the switch component controls the connection branch circuit according to the temperature of the switch component; S202: When the temperature of the switch is at a first temperature, the switch controls the connection branch to be connected; S203: When the temperature of the switch component rises from the first temperature to the second temperature, the switch component controls the connection branch to be disconnected; S204: When the temperature of the switch component drops from the second temperature to a third temperature, the switch component controls the connection branch to be connected; S205: Repeat S203 and S204 according to the temperature of the battery.

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