A method for restoring the capacity of a lithium-ion secondary battery

Abstract

The present application provides a method for capacity recovery of a lithium-ion secondary battery, which comprises the following steps: (1) providing a lithium-ion battery with capacity attenuation; (2) providing a capacity recovery agent, which comprises lithium iodide and an organic solvent, and the organic solvent is used to dissolve the lithium iodide; (3) injecting the capacity recovery agent into the lithium-ion battery with capacity attenuation; (4) allowing the capacity recovery agent to react inside the lithium-ion battery; (5) pouring out the liquid mixture inside the lithium-ion battery after the reaction, and injecting an electrolyte into the lithium-ion battery.

Description

Technical Field

[0001] The present invention relates to the field of lithium-ion secondary batteries, and particularly to a method for restoring the capacity of a lithium-ion secondary battery and a lithium-ion secondary battery obtained by this method. Background Art

[0002] In recent years, with the increasingly wide application scope of lithium-ion secondary batteries (also known as "lithium-ion batteries"), lithium-ion batteries are widely used in energy storage power systems such as hydropower, thermal power, wind power, and solar power stations, as well as in multiple fields such as power tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, and aerospace. However, due to repeated use, the capacity of lithium-ion secondary batteries gradually decreases, affecting their service life and safety. At present, there is still a lack of in-depth research on the capacity restoration of lithium-ion secondary batteries with capacity attenuation. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for efficiently and precisely restoring the capacity of a lithium-ion secondary battery using a capacity restoration agent, and the capacity restoration agent does not remain in large amounts inside the secondary battery, ensuring the cycle stability of the subsequent use of the secondary battery.

[0004] To achieve the above purpose, the present application provides a method for restoring the capacity of a lithium-ion secondary battery, which comprises the following steps:

[0005] (1) Provide a lithium-ion battery with capacity attenuation;

[0006] (2) Provide a capacity restoration agent, the capacity restoration agent comprising lithium iodide and an organic solvent, and the organic solvent is used to dissolve the lithium iodide;

[0007] (3) Inject the capacity restoration agent into the lithium-ion battery with capacity attenuation;

[0008] (4) Make the capacity restoration agent react inside the lithium-ion battery;

[0009] (5) Pour out the liquid mixture inside the lithium-ion battery after the reaction, and inject an electrolyte into the lithium-ion battery.

[0010] Thus, the present application effectively restores the capacity of the lithium-ion secondary battery by using a specific type of capacity restoration agent and replacing the new electrolyte after the reaction of the capacity restoration agent, while ensuring the cycle stability of the subsequent use of the secondary battery.

[0011] In any embodiment, in the step (1), the lithium-ion secondary battery with capacity attenuation is an active lithium attenuation battery, the capacity to be restored of the lithium-ion battery with capacity attenuation is C, and the calculation method of C is:

[0012] C = C2 + C3 - C1,

[0013] where C2 = C1 / (1 - P1), and

[0014] P1 is the loss rate of active lithium of the lithium-ion battery with capacity attenuation;

[0015] C1 is the discharge capacity of the lithium-ion battery with capacity attenuation in the current state;

[0016] C2 is the discharge capacity corresponding to the maximum accommodation of active lithium by the positive electrode material of the lithium-ion battery;

[0017] C3 is the capacity that needs to be charged into the lithium-ion battery with capacity attenuation before capacity recovery;

[0018] All the above capacities are in Ah.

[0019] Thus, the capacity that needs to be recovered by the lithium-ion secondary battery can be accurately calculated, so as to perform targeted and precise regulation on the capacity recovery of the lithium-ion secondary battery.

[0020] In any implementation manner, the loss rate P1 of active lithium of the lithium-ion battery with capacity attenuation is greater than or equal to 5%. Thus, the method of the present invention can be used to recover the capacity of the lithium-ion secondary battery.

[0021] In any implementation manner, in the step (2), the added mass m of lithium iodide in the capacity recovery agent and the capacity C that needs to be recovered by the lithium-ion battery with capacity attenuation satisfy:

[0022] m = C * M * 1000 / (n * M li * 3860), where

[0023] M represents the relative molecular mass of lithium iodide, g / mol,

[0024] n represents the number of lithium atoms in lithium iodide,

[0025] M li represents the relative atomic mass of Li atoms, g / mol,

[0026] 3860 is the gram capacity of lithium metal, mAh / g.

[0027] Thus, the mass of lithium iodide required can be accurately calculated, so as to accurately control the capacity recovered by the lithium-ion secondary battery.

[0028] In any embodiment, in the capacity recovery agent of step (2), the content of lithium iodide is 0.5-15% by weight, optionally 0.5-6% by weight, based on the total mass of the capacity recovery agent. Thus, lithium iodide with a specific content in the capacity recovery agent reacts better with the electrode sheets inside the battery, thereby restoring the capacity of the lithium-ion secondary battery.

[0029] In any embodiment, in step (2), the organic solvent comprises a cyclic carbonate and a low-viscosity solvent. Thus, the organic solvent with a specific composition dissolves lithium iodide better, thereby restoring the capacity of the lithium-ion secondary battery.

[0030] In any embodiment, the cyclic carbonate is ethylene carbonate (EC) or propylene carbonate (PC) or a combination thereof; the content of the cyclic carbonate is 10-30% by weight based on the total mass of the organic solvent. Thus, the cyclic carbonate has a high dielectric constant, which can ensure a large solubility of lithium iodide in the organic solvent.

[0031] In any embodiment, the low-viscosity solvent is one or more of dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, methyl propyl carbonate, methyl formate, ethyl formate, methyl acetate, ethyl acetate, propyl propionate, ethyl butyrate, ethyl propionate, propyl butyrate, tetrahydrofuran, 1,3-dioxolane; the content of the low-viscosity solvent is 70-90% by weight based on the mass of the organic solvent. Thus, the low-viscosity solvent with a specific type and content can alleviate the too-high viscosity of the cyclic carbonate, enabling the inside of the battery to be fully wetted, thereby ensuring the capacity recovery of the lithium-ion secondary battery.

[0032] In any embodiment, in step (4), the capacity recovery agent is allowed to react inside the lithium-ion secondary battery by standing at 20-60°C. Under the reaction conditions, the capacity recovery agent fully wets the inside of the lithium-ion secondary battery, ensuring the capacity recovery of the lithium-ion secondary battery.

[0033] In any embodiment, in step (4), the capacity recovery agent can be made to react inside the lithium-ion battery by ultrasonic treatment or heating. Thus, the wetting of the capacity recovery agent on the electrode sheets inside the lithium-ion secondary battery can be accelerated, the reaction rate can be increased, and the efficiency of the capacity recovery of the secondary battery can be improved.

[0034] In any embodiment, in step (5), after pouring out the liquid mixture inside the lithium-ion secondary battery after the reaction, an organic cleaning agent is injected for cleaning, then vacuum drying is performed, and finally an electrolyte is injected into the lithium-ion battery. Thus, there is no residue of the capacity recovery agent inside the battery, ensuring the cycle stability and safety of the lithium-ion secondary battery after capacity recovery.

[0035] The second aspect of the present application provides a lithium-ion secondary battery, characterized in that it is a lithium-ion secondary battery obtained by the method described in the first aspect of the present application. The positive electrode active material of the lithium-ion secondary battery is at least one of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and lithium-containing phosphate in olivine structure. Optionally,

[0036] The lithium-containing phosphate in olivine structure is at least one of lithium iron phosphate, a composite material of lithium iron phosphate and carbon, lithium manganese phosphate, a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon.

[0037] The third aspect of the present application provides a battery module, including the secondary battery of the second aspect of the present application.

[0038] The fourth aspect of the present application provides a battery pack, including the battery module of the third aspect of the present application.

[0039] The fifth aspect of the present application provides an electrical device, including at least one selected from the secondary battery of the second aspect of the present application, the battery module of the third aspect of the present application, or the battery pack of the fourth aspect of the present application.

[0040] The present application adds a capacity recovery agent containing lithium iodide to a lithium-ion secondary battery with capacity attenuation, supplements active lithium to the positive electrode plate inside the lithium-ion secondary battery, and activates the inactive lithium at the negative electrode, ensuring efficient and precise control of the capacity recovery of the lithium-ion secondary battery; and replaces the electrolyte with a new one after the capacity recovery agent reacts to eliminate the impact of the capacity recovery agent on the safety and cycle stability of the subsequent operation of the lithium-ion secondary battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic flow chart of the method of a preferred embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] Hereinafter, embodiments of the method for recovering the capacity of the lithium-ion secondary battery, the corresponding secondary battery, battery module, battery pack, and electrical device of the present application are specifically disclosed with appropriate reference to the drawings. However, there may be cases where unnecessary details are omitted. For example, there are cases where details of well-known matters are omitted and repeated descriptions of actually identical structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter recited in the claims.

[0043] The "ranges" disclosed in this application are defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The ranges defined in this way can include or exclude the end values, and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60 - 120 and 80 - 110 are listed for a specific parameter, ranges of 60 - 110 and 80 - 120 are also contemplated. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, then the following ranges are all contemplated: 1 - 3, 1 - 4, 1 - 5, 2 - 3, 2 - 4, and 2 - 5. In this application, unless otherwise stated, the numerical range "a - b" represents an abbreviated representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "0 - 5" means that all real numbers between "0 - 5" are fully listed herein, and "0 - 5" is only an abbreviated representation of these numerical combinations. Additionally, when stating that a certain parameter is an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, the integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0044] If there is no special instruction, all embodiments and optional embodiments of this application can be combined with each other to form a new technical solution.

[0045] If there is no special instruction, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0046] If there is no special instruction, all steps of this application can be carried out in sequence or randomly, preferably in sequence. For example, the method includes steps (a) and (b), which means that the method can include steps (a) and (b) carried out in sequence, or can also include steps (b) and (a) carried out in sequence. For example, when it is mentioned that the method may further include step (c), it means that step (c) can be added to the method in any order. For example, the method can include steps (a), (b), and (c), or can also include steps (a), (c), and (b), or can also include steps (c), (a), and (b), etc.

[0047] If there is no special instruction, the "including" and "comprising" mentioned in this application mean open-ended or can also be closed-ended. For example, the "including" and "comprising" can mean that other components not listed can also be included or comprised, or can only include or comprise the listed components.

[0048] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0049] Currently, lithium-ion secondary batteries are widely used in various fields with a large usage volume. However, their capacity gradually decays during repeated charging and discharging. Most of the existing technical solutions add lithium supplement additives to the fresh battery cells to make the initial active lithium content in the cells relatively high; but there is no mention of the recovery after the battery capacity decays. Regarding the capacity recovery of secondary batteries with capacity decay, the research by those skilled in the art is very limited. It is only mentioned that a capacity recovery agent can be added to the secondary battery with capacity decay, but the degree of capacity recovery is limited and precise control of capacity recovery cannot be achieved. Moreover, the capacity recovery agent remains in the electrolyte system after capacity recovery, which will affect the subsequent cycle stability of the battery cells. Through a large amount of research, the inventors have found that the method in the first aspect of the present invention can efficiently and precisely recover the capacity of lithium-ion secondary batteries by precisely controlling the addition of a capacity recovery agent of a specific type and content and replacing the electrolyte, and the capacity recovery agent does not remain inside the secondary battery, ensuring the subsequent cycle stability of the secondary battery.

[0050] Method for recovering the capacity of a lithium-ion secondary battery

[0051] In one embodiment of the present application, referring to Figure 1 , the present application provides a method for recovering the capacity of a lithium-ion secondary battery, which comprises the following steps:

[0052] (1) Provide a lithium-ion battery with capacity decay;

[0053] (2) Provide a capacity recovery agent, which comprises lithium iodide and an organic solvent, and the organic solvent is used to dissolve the lithium iodide;

[0054] (3) Inject the capacity recovery agent into the lithium-ion battery with capacity decay;

[0055] (4) Make the capacity recovery agent react inside the lithium-ion battery;

[0056] (5) Pour out the liquid mixture inside the lithium-ion battery after the reaction, and inject an electrolyte into the lithium-ion battery.

[0057] Although the mechanism is not yet clear, the applicant unexpectedly found that: by using a capacity recovery agent containing lithium iodide and replacing the electrolyte with a new one after the reaction of the capacity recovery agent, the capacity of the lithium-ion secondary battery was effectively restored, while ensuring the cycle stability of the secondary battery during subsequent use. Specifically, taking the lithium iron phosphate type lithium-ion secondary battery as an example, lithium iodide reacts with iron phosphate of the lithium-depleted cathode to form lithium iron phosphate and triiodide ions (I3 - ):

[0058] 2Li + +3I ˉ +2FePO4=2LiFePO4+I3 ˉ ;

[0059] During this reaction process, lithium in lithium iodide enters the cathode as an external lithium source through a redox reaction, increasing the total amount of available active lithium inside the secondary battery.

[0060] Meanwhile, at the anode, triiodide ions (I3 - ) can react with inactive lithium (lithium oxide in the SEI film (solid electrolyte interface film) and lithium deposited on the anode surface) to form soluble LiI;

[0061] 3Li2O+3I3 ˉ =6Li + +IO3 ˉ +8I ˉ ;

[0062] The soluble LiI can then react with FePO4 of the anode to form LiFePO4:

[0063] 2Li+I3 ˉ =2Li + +3I ˉ ;

[0064] Therefore, this activates the inactive lithium, thus achieving the capacity recovery of the secondary battery.

[0065] The term "active lithium" refers to lithium ions that can participate in redox reactions during the charge and discharge process of the battery.

[0066] In some embodiments, in step (1), the lithium-ion secondary battery with capacity attenuation is an active lithium attenuation battery, and the capacity to be restored of the lithium-ion battery with capacity attenuation is C. The calculation method of C is:

[0067] C=C2+C3-C1,

[0068] where C2=C1 / (1-P1),

[0069] where,

[0070] P1 is the active lithium loss rate of the lithium-ion battery with capacity attenuation;

[0071] C1 is the discharge capacity of the lithium-ion battery with capacity attenuation in its current state;

[0072] C2 is the discharge capacity corresponding to the maximum amount of active lithium that the positive electrode material of the lithium-ion battery can accommodate;

[0073] C3 is the capacity that needs to be charged into the lithium-ion battery with capacity attenuation before capacity recovery;

[0074] All the above capacities are in Ah.

[0075] Thus, the capacity that the lithium-ion secondary battery needs to recover can be accurately calculated, so as to perform targeted and precise regulation on the capacity recovery of the lithium-ion secondary battery.

[0076] The "active lithium attenuation battery" is a secondary battery in which the active lithium in the positive electrode gradually decreases after the first formation and / or during use.

[0077] The calculation method of the active lithium loss rate P1 of the lithium-ion secondary battery with capacity attenuation is as follows:

[0078] Active lithium loss rate P1 = (C20 - C10) / C20;

[0079] where C10 is the capacity corresponding to the active lithium in the current state of the battery cathode at 154.025mm 2 C20 is the capacity corresponding to the active lithium that the battery cathode can accommodate at 154.025mm 2 of the battery cathode.

[0080] The test methods for C10 and C20 are as follows:

[0081] Take the cathode electrode of the fully discharged battery, and use a punching machine to punch the cathode electrode into circular pieces with an area of 154.025mm 2 in size, and prepare a button battery of this cathode and lithium. Charge the button battery, and the charging process is shown in Table 1, and record its charging capacity as C10. Discharge and then charge the above button battery, and the process is shown in Table 2, and record its recharging capacity as C20 (here, the active lithium loss caused by the loss of cathode active material is not considered). Among them, the U1 and U2 values of different lithium-ion secondary batteries are shown in Table 3.

[0082] Table 1 Charging process of button battery

[0083]

[0084] Note:

[0085] "0.04C" represents the current of 0.04 times the capacity size.

[0086] Table 2 Discharge and Recharge Process of Button Batteries

[0087]

[0088] Table 3 U1 and U2 of Different Lithium-Ion Secondary Batteries

[0089] Positive electrode active material <![CDATA[U1(V)]]> <![CDATA[U2(V)]]> Lithium iron phosphate 3.75 2 NCM532 4.25 2.8 Lithium cobalt oxide 4.25 2.8 Lithium manganate 4.3 2.5

[0090] When the secondary battery performs capacity recovery in a fully discharged state, if C3 is 0 Ah, then C = C2 - C1.

[0091] In some embodiments, the active lithium loss rate P1 of the lithium-ion secondary battery with capacity attenuation is greater than or equal to 5%. Thus, the method of the present invention can be used to recover the capacity of the lithium-ion secondary battery.

[0092] In some embodiments, in step (2), the added mass m of lithium iodide in the capacity recovery agent and the capacity C to be recovered of the lithium-ion battery with capacity attenuation satisfy:

[0093] m = C * M * 1000 / (n * M li * 3860), where

[0094] M represents the relative molecular mass of lithium iodide, g / mol,

[0095] n represents the number of lithium atoms in lithium iodide,

[0096] M li represents the relative atomic mass of Li atoms, g / mol,

[0097] 3860 is the gram capacity of lithium metal, mAh / g.

[0098] Thus, the mass of lithium iodide required can be accurately calculated, thereby accurately controlling the capacity recovered by the lithium-ion secondary battery.

[0099] In some embodiments, in the capacity recovery agent, the content of lithium iodide is 0.5-15% by weight, optionally 0.5-6% by weight, based on the total mass of the capacity recovery agent. Thus, a specific content of lithium iodide in the capacity recovery agent can better react with the electrode sheets inside the battery, thereby recovering the capacity of the lithium-ion secondary battery. When the capacity to be recovered by the lithium-ion secondary battery is fixed, the lower the concentration of lithium iodide in the capacity recovery agent, the greater the total amount of the capacity recovery agent required. Therefore, the concentration of lithium iodide is not easily lower than 0.5% by weight. At the same time, the higher the concentration of lithium iodide, the greater the viscosity of the solvent recovery agent, which will make it difficult for the capacity recovery agent to diffuse on the electrode sheets, resulting in uneven distribution of the capacity recovery effect on the cathode electrode sheet, and even the middle part of the electrode sheet cannot react with the capacity recovery agent and no capacity recovery can be obtained. Therefore, the concentration of lithium iodide is not easily higher than 15% by weight.

[0100] In some embodiments, in step (2), the organic solvent comprises a cyclic carbonate and a low-viscosity solvent. The cyclic carbonate has a high dielectric constant, which can ensure that lithium iodide has a large solubility in the organic solvent, so that adding a small amount of the capacity recovery agent can also achieve the expected capacity recovery effect. However, the cyclic carbonate has a relatively high viscosity, which will affect the diffusion of the capacity recovery agent between the electrode sheets, making the middle position of the electrode sheet not well infiltrated and unable to participate in the reaction; or reducing the reaction time between the middle position and the solvent recovery agent, making the middle part of the electrode sheet not well activated. At this time, a low-viscosity solvent is added to reduce the viscosity of the system, so that the electrode sheet is fully infiltrated, thereby ensuring that the electrode sheet is fully activated.

[0101] In some embodiments, the cyclic carbonate is ethylene carbonate (EC) or propylene carbonate (PC) or a combination thereof, preferably ethylene carbonate; the content of the cyclic carbonate is 10-30% by weight, preferably 20-30% by weight, based on the total mass of the organic solvent. Thus, a specific type of cyclic carbonate further ensures that lithium iodide has a large solubility in the organic solvent, so that adding a small amount of the capacity recovery agent can also achieve the expected capacity recovery effect.

[0102] In some embodiments, the low-viscosity solvent is one or more of dimethyl carbonate (DMC), diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, methyl formate, ethyl formate, methyl acetate, ethyl acetate, propyl propionate, ethyl butyrate, ethyl propionate, butyl propionate, tetrahydrofuran, 1,3-dioxolane; preferably dimethyl carbonate; the content of the low-viscosity solvent is 70-90% by weight, preferably 70-80% by weight, based on the mass of the organic solvent. Thus, a specific type and content of the low-viscosity solvent can alleviate the too high viscosity of the cyclic carbonate, so that the inside of the battery is fully infiltrated, thereby ensuring the capacity recovery of the lithium-ion secondary battery.

[0103] In some embodiments, in step (3), the capacity recovery agent is injected into the lithium-ion battery with capacity fade. Before injecting the capacity recovery agent, the electrolyte in the battery can be poured out, or the capacity recovery agent can be directly injected without pouring out the electrolyte. Preferably, the electrolyte in the battery is poured out before injecting the capacity recovery agent. Those skilled in the art should be aware that when the capacity of the lithium-ion battery fades severely, there is very little free electrolyte remaining in the battery. At this time, the capacity recovery agent can be directly injected into the battery. The injection method of the capacity recovery agent can be any method known to those skilled in the art, such as injection through a syringe.

[0104] In some embodiments, in step (4), the capacity recovery agent is allowed to react inside the lithium-ion battery by standing at a temperature of 20 - 60 °C, preferably 20 - 45 °C. Generally, the standing time is 24 - 72 hours, preferably 45 - 55 hours. Under the reaction conditions, the capacity recovery agent fully infiltrates the inside of the lithium-ion secondary battery, ensuring the capacity recovery of the lithium-ion secondary battery.

[0105] In some embodiments, in step (4), the capacity recovery agent can be made to react inside the lithium-ion battery by ultrasonic treatment or heating. In some embodiments, ultrasonic treatment can be carried out at a frequency of 25 KHz - 80 KHz, preferably 30 - 50 KHz for 2 - 4 h, preferably 2 h, to accelerate the reaction of the capacity recovery agent inside the lithium-ion secondary battery. In some embodiments, heating can be carried out in an oven at 20 - 45 °C for 1 - 4 h to accelerate the reaction of the capacity recovery agent inside the lithium-ion secondary battery. Thus, the infiltration of the capacity recovery agent into the electrode sheets inside the lithium-ion secondary battery can be accelerated, the reaction rate can be increased, and the efficiency of capacity recovery of the secondary battery can be improved.

[0106] In some embodiments, in step (5), after pouring out the liquid mixture inside the lithium-ion battery after the reaction, an organic cleaning agent is injected for cleaning, then vacuum drying is carried out, and finally an electrolyte is injected into the lithium-ion battery. Thereby, no residue of the capacity recovery agent remains inside the battery, ensuring the cycle stability and safety of the lithium-ion secondary battery after capacity recovery.

[0107] In some embodiments, the organic cleaning agent is the same as the above-mentioned low-viscosity solvent, preferably DMC. After cleaning with the organic cleaning agent, the secondary battery is usually vacuum dried at a temperature of 20 - 45 °C, preferably at room temperature, under a vacuum degree of -0.08 to -0.1 MPa. Usually, the vacuum drying time is 0.2 - 1 hour, preferably 0.5 hour.

[0108] In some embodiments, by implementing the method of the present application, the capacity recovery rate of the lithium-ion secondary battery is 0.5% - 15%.

[0109] The capacity recovery rate P of the secondary battery is calculated by the following formula:

[0110] P = (Ca - Cb) / Cb * 100%;

[0111] Where

[0112] Cb is the discharge capacity of the battery before capacity recovery, in Ah;

[0113] Ca is the discharge capacity of the battery after capacity recovery, in Ah.

[0114] The test methods for Ca and Cb are as follows:

[0115] At 25 °C, the lithium-ion secondary battery is charged at a constant current of 0.04C to U 10 , left to stand for 5 min, and then discharged at 0.04C to U 20 . The obtained discharge capacity is recorded as the initial discharge capacity C0, where U 10 and U 20 values are shown in Table 4.

[0116] Table 4 U of different lithium-ion secondary batteries 10 and U 20

[0117] Positive electrode active material <![CDATA[U 10 (V)]]> <![CDATA[U 20 (V)]]> Lithium iron phosphate 3.65 2.5 NCM532 4.25 2.8 Lithium cobalt oxide 4.25 2.8 Lithium manganate 4.25 2.5

[0118] Repeat the above steps 3 times for the same battery, and record the discharge capacity Cn of the battery after the nth time at the same time. Take the average value of the 3 discharge capacities as the discharge capacity Cb of the battery before capacity recovery. After the battery undergoes capacity recovery, repeat the above charge-discharge process 3 times; take the average value of the 3 discharge capacities as the discharge capacity Ca of the battery after capacity recovery.

[0119] The test method for the capacity C1 of the current state of the lithium-ion secondary battery with capacity attenuation is the same as the test method for Cb.

[0120] The second aspect of the present application provides a lithium-ion secondary battery, characterized in that it is a lithium-ion secondary battery obtained by the method described in the first aspect of the present application, and the positive electrode active material of the lithium-ion secondary battery is at least one of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and lithium-containing phosphate with olivine structure. Optionally,

[0121] The lithium-containing phosphate with olivine structure is at least one of lithium iron phosphate, a composite material of lithium iron phosphate and carbon, lithium manganese phosphate, a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon.

[0122] Under normal circumstances, a secondary battery includes a positive electrode sheet, a negative electrode sheet, an electrolyte, and a separator. During the charge and discharge process of the battery, active ions are embedded and extracted back and forth between the positive electrode sheet and the negative electrode sheet. The electrolyte plays a role in conducting ions between the positive electrode sheet and the negative electrode sheet. The separator is disposed between the positive electrode sheet and the negative electrode sheet, mainly to prevent short circuit between the positive and negative electrodes, and at the same time allows ions to pass through.

[0123] [Positive electrode sheet]

[0124] The positive electrode sheet includes a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector, and the positive electrode film layer includes the positive electrode active material of the first aspect of the present application.

[0125] As an example, the positive electrode current collector has two surfaces opposite to each other in its own thickness direction, and the positive electrode film layer is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.

[0126] In some embodiments, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum foil can be used. The composite current collector may include a polymer material substrate and a metal layer formed on at least one surface of the polymer material substrate. The composite current collector can be formed by forming a metal material (such as aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0127] In some embodiments, the positive electrode active material may be a positive electrode active material known in the art for use in batteries. As an example, the positive electrode active material is lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (which can also be abbreviated as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (which can also be abbreviated as NCM523), LiNi 0.5 Co 0.25 Mn 0.25 O2 (which can also be abbreviated as NCM211), LiNi 0.6 Co 0.2 Mn 0.2 O2 (which can also be abbreviated as NCM622), LiNi 0.8 Co 0.1Mn 0.1 O2 (which can also be abbreviated as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2), at least one of the lithium-containing phosphates with olivine structure. Optionally, the lithium-containing phosphates with olivine structure may include, but are not limited to, lithium iron phosphate (such as LiFePO4 (which can also be abbreviated as LFP)), composite materials of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), composite materials of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and composite materials of lithium manganese iron phosphate and carbon. However, the present application is not limited to these materials, and other conventional materials that can be used as the positive electrode active material of the battery can also be used. These positive electrode active materials can be used alone or in combination of two or more.

[0128] In some embodiments, the positive electrode film layer may further optionally include a binder. As an example, the binder may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resin.

[0129] In some embodiments, the positive electrode film layer may further optionally include a conductive agent. As an example, the conductive agent may include at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0130] In some embodiments, the positive electrode plate can be prepared by the following method: dispersing the above components for preparing the positive electrode plate, such as the positive electrode active material, the conductive agent, the binder, and any other components, in a solvent (such as N-methylpyrrolidone) to form a positive electrode slurry; coating the positive electrode slurry on the positive electrode current collector, and after processes such as drying and cold pressing, the positive electrode plate can be obtained.

[0131] [Negative electrode plate]

[0132] The negative electrode plate includes a negative electrode current collector and a negative electrode film layer provided on at least one surface of the negative electrode current collector, and the negative electrode film layer includes a negative electrode active material.

[0133] As an example, the negative electrode current collector has two surfaces opposite to each other in its own thickness direction, and the negative electrode film layer is provided on any one or both of the two opposite surfaces of the negative electrode current collector.

[0134] In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, copper foil may be used. The composite current collector may include a polymer material substrate and a metal layer formed on at least one surface of the polymer material substrate. The composite current collector may be formed by forming a metal material (such as copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0135] In some embodiments, the negative electrode active material may be a negative electrode active material for batteries well-known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other conventional materials that can be used as battery negative electrode active materials may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0136] In some embodiments, the negative electrode film layer may also optionally include a binder. The binder may be selected from at least one of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS).

[0137] In some embodiments, the negative electrode film layer may also optionally include a conductive agent. The conductive agent may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0138] In some embodiments, the negative electrode film layer may also optionally include other additives, such as thickeners (such as sodium carboxymethyl cellulose (CMC-Na)), etc.

[0139] In some embodiments, the negative electrode plate may be prepared in the following manner: dispersing the components for preparing the negative electrode plate described above, such as the negative electrode active material, the conductive agent, the binder, and any other components, in a solvent (such as deionized water) to form a negative electrode slurry; coating the negative electrode slurry on the negative electrode current collector, and after processes such as drying and cold pressing, the negative electrode plate can be obtained.

[0140] [Electrolyte]

[0141] The electrolyte functions to conduct ions between the positive electrode plate and the negative electrode plate. There is no specific limitation on the type of electrolyte in this application, and it can be selected according to requirements. For example, the electrolyte can be liquid, gel-like, or all-solid state.

[0142] In some embodiments, the electrolyte uses an electrolytic solution. The electrolytic solution includes an electrolyte salt and a solvent.

[0143] In some embodiments, the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium bis(oxalate) borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0144] In some embodiments, the solvent can be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone.

[0145] In some embodiments, the electrolytic solution may also optionally include additives. For example, the additives can include negative electrode film-forming additives, positive electrode film-forming additives, and can also include additives that can improve certain battery performance, such as additives for improving battery overcharge performance, additives for improving battery high-temperature or low-temperature performance, etc.

[0146] [Separator membrane]

[0147] In some embodiments, the secondary battery further includes a separator membrane. There is no particular limitation on the type of separator membrane in this application, and any well-known porous structure separator membrane with good chemical stability and mechanical stability can be selected.

[0148] In some embodiments, the material of the separator membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator membrane can be a single-layer thin film or a multi-layer composite thin film, with no particular limitation. When the separator membrane is a multi-layer composite thin film, the materials of each layer can be the same or different, with no particular limitation.

[0149] In some embodiments, the positive electrode plate, the negative electrode plate, and the separator membrane can be made into an electrode assembly by a winding process or a stacking process.

[0150] In some embodiments, the secondary battery can include an outer package. The outer package can be used to encapsulate the above electrode assembly and electrolyte.

[0151] In some embodiments, the outer packaging of the secondary battery can be a hard case, such as a hard plastic case, an aluminum case, a steel case, etc. The outer packaging of the secondary battery can also be a soft package, such as a pouch soft package. The material of the soft package can be plastic. As plastics, polypropylene, polybutylene terephthalate, and polybutylene succinate can be listed, etc. Preferably, the outer packaging of the secondary battery is a soft package.

[0152] This application does not particularly limit the shape of the secondary battery, which can be cylindrical, square, or any other arbitrary shape.

[0153] In some embodiments, secondary battery products of different shapes include a box body and the secondary battery of the present invention encapsulated in the box body. The box body can include a housing and a cover plate. Among them, the housing can include a bottom plate and side plates connected to the bottom plate, and the bottom plate and the side plates enclose a receiving cavity. The housing has an opening communicating with the receiving cavity, and the cover plate can be covered on the opening to close the receiving cavity. The positive electrode plate, the negative electrode plate, and the separator can form an electrode assembly through a winding process or a stacking process. The electrolyte is infiltrated into the electrode assembly to form the secondary battery monomer of the present invention. The secondary battery monomer is encapsulated in the receiving cavity. The number of secondary battery monomers contained in the secondary battery 5 can be one or more, and those skilled in the art can select according to specific actual needs.

[0154] In some embodiments, the secondary batteries can be assembled into a battery module. The number of secondary batteries contained in the battery module can be one or more, and the specific number can be selected by those skilled in the art according to the application and capacity of the battery module.

[0155] In the battery module, multiple secondary batteries can be arranged in sequence along the length direction of the battery module. Of course, they can also be arranged in any other arbitrary manner. Further, the multiple secondary batteries can be fixed by fasteners.

[0156] Optionally, the battery module can further include a housing having a receiving space, and multiple secondary batteries are received in the receiving space.

[0157] In some embodiments, the above battery module can also be assembled into a battery pack. The number of battery modules contained in the battery pack can be one or more, and the specific number can be selected by those skilled in the art according to the application and capacity of the battery pack.

[0158] The battery pack can include a battery box and multiple battery modules arranged in the battery box. The battery box includes an upper box body and a lower box body. The upper box body can be covered on the lower box body and form a closed space for receiving the battery modules. The multiple battery modules can be arranged in the battery box in any arbitrary manner.

[0159] In addition, the present application also provides an electrical device, which includes at least one of the secondary battery, battery module, or battery pack provided by the present application. The secondary battery, battery module, or battery pack can be used as the power source of the electrical device or as the energy storage unit of the electrical device. The electrical device can include mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships, satellites, energy storage systems, etc., but is not limited thereto.

[0160] As the electrical device, the secondary battery, battery module, or battery pack can be selected according to its usage requirements.

[0161] The electrical device is a pure electric vehicle, hybrid electric vehicle, or plug-in hybrid electric vehicle, etc. In order to meet the high power and high energy density requirements of the electrical device for the secondary battery, a battery pack or battery module can be used.

[0162] As another example of the device, it can be a mobile phone, tablet computer, laptop, etc. This device usually requires being thin and light, and a secondary battery can be used as the power source.

[0163] Embodiment

[0164] Hereinafter, embodiments of the present application will be described. The embodiments described below are exemplary and are only used to explain the present application and should not be construed as a limitation to the present application. For those not specified in the embodiments regarding specific technologies or conditions, they shall be carried out according to the technologies or conditions described in the literature in the art or according to the product specifications. For reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0165] Embodiment 1

[0166] (1) Take a lithium iron phosphate secondary battery with capacity attenuation; measure the active lithium loss rate P1 of the secondary battery as 20% according to the method described in the instruction manual, and measure the discharge capacity C1 of the battery in the current state as 116 mAh. The tested battery cell is in a fully discharged state, that is, the capacity C3 that needs to be charged into the battery before capacity recovery is 0. Then calculate the capacity C that needs to be recovered for the lithium iron phosphate battery with capacity attenuation as 29 mAh according to the following formula:

[0167] C = C2 + C3 - C1,

[0168] where C2 = C1 / (1 - P1),

[0169] where,

[0170] P1 is the active lithium loss rate of the lithium iron phosphate battery with capacity attenuation;

[0171] C1 is the discharge capacity of the lithium iron phosphate battery with capacity attenuation at the current state;

[0172] C2 is the discharge capacity corresponding to the maximum accommodation of active lithium in the cathode material of the lithium iron phosphate battery;

[0173] C3 is the capacity that needs to be charged into the lithium iron phosphate battery with capacity attenuation before capacity recovery;

[0174] Each of the above capacities is in Ah;

[0175] (2) Calculate the added mass m of lithium iodide as 0.146 g according to the capacity C to be recovered of the lithium iron phosphate battery obtained in step (1):

[0176] m = C * M * 1000 / (n * M li * 3860), where

[0177] M represents the relative molecular mass of lithium iodide, g / mol,

[0178] n represents the number of lithium atoms in lithium iodide,

[0179] M li represents the relative atomic mass of Li atoms, g / mol,

[0180] 3860 represents the gram capacity of lithium metal, mAh / g.

[0181] Dissolve the above amount of lithium iodide in 14.6 g of a mixed solvent of ethylene carbonate and dimethyl carbonate with a mass ratio of 3:7 to provide a capacity recovery agent

[0182] (3) Use a tool to cut open a corner of the soft-pack lithium iron phosphate battery cell, and pour out the electrolyte. Then use a syringe to inject 10 g of the capacity recovery agent obtained in step (2) into the lithium ion secondary battery cell. Then use a heat sealer to seal the cell, and the encapsulation conditions are 140 °C and 10 s.

[0183] (4) Let the above cell stand at 25 °C for 48 h to allow the capacity recovery agent to react inside the lithium iron phosphate battery;

[0184] (5) Cut open a corner of the cell in step (4), and pour out the liquid mixture inside the lithium iron phosphate battery after reaction. Then inject 10 g of DMC into the cell and soak for 30 min, and then pour it out. Repeat the above operation 6 times. Then dry the cell at 25 °C under a vacuum of -0.1 MPa for 30 min. Then inject electrolyte into the cell. Then use a heat sealer to seal the cell, and the encapsulation conditions are 140 °C and 10 s.

[0185] Example 2-18

[0186] The same steps as in Example 1 were carried out, except for changing the type and mass of the mixed solvent in the solvent recovery agent, the ratio of different solvents in the mixed solvent, the type of battery, the state of charge of the battery before recovery, and the reaction conditions. See Table 1 for details.

[0187] Comparative Example 1

[0188] The same steps as in Example 1 were carried out, except that in step (3), the electrolyte was not poured out and step (5) was not carried out.

[0189] Comparative Example 2

[0190] The same steps as in Example 1 were carried out, except that lithium iodide was not added.

[0191] Table 1

[0192]

[0193] Battery performance test

[0194] For the batteries after capacity recovery in the above examples and comparative examples, the discharge capacities before and after capacity recovery were tested according to the method described in the specification, and the corresponding capacity recovery rate P was calculated. The results are shown in Table 2.

[0195] Table 2

[0196]

[0197] According to the above results, it can be seen that for the lithium-ion secondary batteries of Examples 1-17 of the present invention, after capacity recovery by the method of the present invention, their capacity recovery rates all reached the ideal range (all greater than or equal to 5%, and even up to more than 20%), and the cycle retention rate of the battery after capacity recovery after 500 cycles at 25 °C still remained at a high level (above 80%).

[0198] In contrast, for Comparative Example 1, the capacity recovery rate was 13% without pouring out the reaction mixture after the reaction of the capacity recovery agent and directly using it, but the cycle retention rate was only 80%, both lower than those of the examples. For Comparative Example 2, the capacity recovery agent did not contain lithium iodide. After treating the battery using the same method as the present invention, the capacity of the battery basically did not change, and the effect of battery capacity recovery could not be achieved.

[0199] It should be noted that this application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and embodiments with the same structure in essence as the technical idea and achieving the same effects within the scope of the technical solution of this application are all included in the technical scope of this application. In addition, within the scope of not departing from the gist of this application, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways constructed by combining some of the constituent elements in the embodiments are also included in the scope of this application.

Claims

1. A method for capacity recovery of a lithium-ion battery, characterized in that, It includes the following steps: (1) Provide a lithium-ion battery with capacity attenuation; (2) Provide a capacity recovery agent, which contains lithium iodide and an organic solvent for dissolving the lithium iodide; (3) Inject the capacity recovery agent into the lithium-ion battery with capacity attenuation; (4) Make the capacity recovery agent react inside the lithium-ion battery; (5) Pour out the liquid mixture inside the lithium-ion battery after the reaction, and inject electrolyte into the lithium-ion battery; In the step (1), the lithium-ion battery with capacity attenuation is an active lithium attenuation battery, and the capacity to be recovered by the lithium-ion battery with capacity attenuation is C. The calculation method of C is as follows: C = C2 + C3 - C1, where C2 = C1 / (1 - P1), where, P1 is the active lithium loss rate of the lithium-ion battery with capacity attenuation; C1 is the discharge capacity of the lithium-ion battery with capacity attenuation in the current state; C2 is the discharge capacity corresponding to the maximum accommodation of active lithium by the cathode material of the lithium-ion battery; C3 is the capacity that needs to be charged into the lithium-ion battery with capacity attenuation before capacity recovery; All the above capacities are in Ah.

2. The method according to claim 1, characterized in that The active lithium loss rate P1 of the lithium-ion battery with capacity attenuation is greater than or equal to 5%.

3. The method according to claim 1, wherein in the step (2), the added mass m of lithium iodide in the capacity recovery agent and the capacity C to be recovered by the lithium-ion battery with capacity attenuation satisfy: m = C * M * 1000 / (n * M li * 3860), where, M represents the relative molecular mass of lithium iodide, g / mol, n represents the number of lithium atoms in lithium iodide, M li represents the relative atomic mass of Li atoms, g / mol, 3860 is the gram capacity of lithium metal, mAh / g.

4. The method according to claim 1, wherein in the capacity recovery agent in the step (2), the content of lithium iodide is 0.5 - 15% by weight, based on the total mass of the capacity recovery agent.

5. The method according to claim 1, wherein the content of lithium iodide is 0.5 - 6% by weight, based on the total mass of the capacity recovery agent.

6. The method according to claim 1, wherein In the step (2), the organic solvent includes cyclic carbonates and low-viscosity solvents.

7. The method according to claim 6, characterized in that, The cyclic carbonate is ethylene carbonate (EC) and / or propylene carbonate (PC); the content of the cyclic carbonate is 10 - 30% by weight, based on the mass of the organic solvent.

8. The method according to claim 6 or 7, characterized in that, The low-viscosity solvent is one or more of dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, methyl propyl carbonate, methyl formate, ethyl formate, methyl acetate, ethyl acetate, propyl propionate, ethyl butyrate, ethyl propionate, propyl butyrate, tetrahydrofuran, 1,3-dioxolane; the content of the low-viscosity solvent is 70 - 90% by weight, based on the total mass of the organic solvent.

9. The method according to claim 1, wherein In the step (4), the capacity recovery agent reacts inside the lithium-ion battery by standing at 20 - 60°C.

10. The method according to claim 8, characterized in that, In the step (4), the capacity recovery agent reacts inside the lithium-ion battery by ultrasonic or heating.

11. The method according to claim 1, characterized in that In the step (5), after pouring out the liquid mixture inside the lithium-ion battery after the reaction, an organic cleaning agent is injected for cleaning, then vacuum drying is carried out, and finally an electrolyte is injected into the lithium-ion battery.

12. A lithium-ion battery after capacity recovery, characterized in that, It is a lithium-ion battery obtained by the method according to any one of claims 1-11, and the positive electrode active material of the lithium-ion battery is at least one of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and lithium-containing phosphate with an olivine structure.

13. The lithium-ion battery according to claim 12, wherein the lithium-containing phosphate with an olivine structure is at least one of lithium iron phosphate, a composite material of lithium iron phosphate and carbon, lithium manganese phosphate, a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon.

14. A battery module, characterized in that, It includes the lithium-ion battery according to claim 12 or 13.

15. A battery pack, characterized in that, It includes the battery module according to claim 14.

16. An electrical device, characterized in that, It includes at least one selected from the lithium-ion battery according to claim 12 or 13, the battery module according to claim 14, or the battery pack according to claim 15.

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