Method for extending battery life, electric device and storage medium

Abstract

The present application provides a method for extending the life of a battery, an electric device, and a storage medium. The method is applied in an electric device, wherein the electric device includes a battery, and the battery includes a plurality of battery cells. The method includes: when the electric device is in a stationary state for a first preset time t1 and the voltage V1 of any one of the plurality of battery cells is in a first preset voltage range, discharging the battery through a current I0; when the electric device is in a non-stationary state or the voltage V2 of any one of the plurality of battery cells is less than or equal to any voltage value in a second preset voltage range, stopping discharging the battery, wherein V1>V2, and 0.02V≤V1‑V2≤1.1V. The present application can extend the service life of a battery without changing the chemical system of the battery.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a method for extending battery life, an electric device, and a storage medium. Background Art

[0002] Lithium manganese oxide is a material suitable for the electric equipment (two-wheeled and three-wheeled electric vehicles) market because of its advantages such as low cost, good safety, good low-temperature performance and high voltage platform. In recent years, the application of lithium manganese oxide in the lithium battery industry has become more and more extensive. The manganese-based multi-composite system is the mainstream technical route for batteries for electric equipment, and it also has a place in the field of passenger cars and commercial electric vehicles. At present, batteries with different lithium manganese oxide (LMO) material systems all have capacity loss after storage, which in turn affects the service life of the battery. Summary of the invention

[0003] In view of this, it is necessary to provide a method for extending the battery life, an electric device and a storage medium, which can extend the battery life of the battery.

[0004] An embodiment of the present application provides a method for extending battery life, which is applied to an electric device, wherein the electric device includes a battery, and the battery includes multiple battery cells. The method includes: when the electric device is in a stationary state for a first preset time t1 and the voltage V1 of any one of the multiple battery cells is in a first preset voltage range, discharging the battery through a current I0; when the electric device is in a non-stationary state or the voltage V2 of any one of the multiple battery cells is less than or equal to any voltage value in a second preset voltage range, stopping discharging the battery, wherein V1>V2, and 0.02V≤V1-V2≤1.1V.

[0005] According to some embodiments of the present application, 0.2V≤V1-V2≤1.0V.

[0006] According to some embodiments of the present application, the first preset voltage range is greater than or equal to 3.1V and less than or equal to 3.9V; the second preset voltage range is greater than or equal to 2.8V and less than 3.1V.

[0007] According to some embodiments of the present application, 0<t1≤8 days.

[0008] According to some embodiments of the present application, the method also includes: when the electric device is in a stationary state for a second preset time t2 and the voltage V3 of any one of the multiple battery cells is in a third preset voltage range, discharging the battery through the current I0; when the electric device is in a non-stationary state or the voltage V4 of any one of the multiple battery cells is less than or equal to any voltage value in the second preset voltage range, stopping discharging the battery, wherein V3>V4, and 0.8V≤V3-V4≤1.5V.

[0009] According to some embodiments of the present application, 1.0V≤V3-V4≤1.3V.

[0010] According to some embodiments of the present application, the third preset voltage range is greater than 3.9V and less than or equal to 4.1V.

[0011] According to some embodiments of the present application, 8 days ≤ t2 ≤ 365 days.

[0012] According to some embodiments of the present application, the current I0 is greater than 0 mA and less than or equal to 500 mA.

[0013] According to some embodiments of the present application, the current I0 is greater than or equal to 10 mA and less than or equal to 300 mA.

[0014] According to some embodiments of the present application, the current I0 is greater than or equal to 20 mA and less than or equal to 200 mA.

[0015] According to some embodiments of the present application, the battery includes a positive electrode plate, the positive electrode plate includes a positive electrode current collector and a positive electrode active material layer coated on the positive electrode current collector, the positive electrode active material layer includes a positive electrode active material, and the positive electrode active material includes a mixture of lithium manganate and LiMO, wherein the chemical formula of LiMO is: Li x Co y Ni z M 1-y-z O b- a X b , 0.8<x≤1.2, 0≤y≤0.5, 0.5≤z≤1.0, 1.8≤b≤2.2 and 0≤a≤1.0.

[0016] An embodiment of the present application provides an electric device, which includes: a battery and a processor, the battery is used to power the electric device, and the battery includes a plurality of battery cells; the processor is used to execute the method for extending the battery life as described above.

[0017] An embodiment of the present application provides a storage medium on which at least one computer instruction is stored. The computer instruction is loaded by a processor and used to execute the method for extending battery life as described above.

[0018] A method for extending the life of a battery provided in an embodiment of the present application is targeted at a battery system that is an LMO material system and a mixed system containing LMO materials. When the BMS detects that the voltage of any cell in the battery is within a first preset voltage range and the standing time exceeds a certain time, the self-discharge strategy is started until the detected voltage is less than or equal to any voltage value in a second preset voltage range, and the self-discharge strategy is turned off. Starting from the storage capacity loss unique to LMO materials and their mixed materials, the present application can utilize the BMS self-discharge strategy without changing the overall design of the cell and without increasing costs, to solve the problem of reducing the probability of battery storage capacity loss at a specific voltage from a system level, thereby extending the battery's service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of an electric device according to an embodiment of the present application.

[0020] Figure 2 The present invention is a flowchart of a method for extending battery life according to an embodiment of the present invention.

[0021] Figure 3 This is a flow chart of a method for extending battery life according to another embodiment of the present application.

[0022] Figure 4 This is a battery life prediction graph obtained by using the method for extending battery life provided in this application for the battery prepared in Example 1.

[0023] Figure 5 A battery life prediction graph obtained by using the method for extending battery life provided in this application for the battery prepared in Example 2.

[0024] Figure 6 A battery life prediction graph obtained by using the method for extending battery life provided in the present application for the battery prepared in Example 3.

[0025] Figure 7 A battery life prediction graph obtained by using the method for extending battery life provided in this application for the battery prepared in Example 4.

[0026] Main component symbols

[0027] Electric equipment 100

[0028] Memory 11

[0029] Processor 12

[0030] Battery 13

[0031] Battery Cell 130

[0032] Collection device 14

[0033] Timer 15

[0034] The following specific implementation methods will further illustrate the present application in detail in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0036] See also Figure 1 , Figure 1 The schematic diagram of an electric device according to an embodiment of the present application is as follows. The electric device 100 includes, but is not limited to, a memory 11, at least one processor 12, a battery 13, a collection device 14, and a timer 15, and the above components may be connected via a bus or directly.

[0037] It should be noted that Figure 1 The electric device 100 is merely an example. In other embodiments, the electric device 100 may include more or fewer components, or have a different component configuration. The electric device 100 may be an electric tool, an electric motorcycle, an electric bicycle, an electric car, a mobile phone, a tablet computer, a digital assistant, a personal computer, or any other suitable rechargeable device.

[0038] In one embodiment, the battery 13 is a rechargeable battery for providing electrical energy to the electric device 100. For example, the battery 13 can be a lead-acid battery, a nickel-cadmium battery, a nickel-metal hydride battery, a lithium-ion battery, a lithium polymer battery, and a lithium iron phosphate battery. The battery 13 is logically connected to the processor 12 through a battery management system (Battery Management System, BMS), so that the battery management system can realize functions such as charging and discharging. The battery management system can be connected to the energy storage inverter (Power Conversion System, PCS) via CAN or RS485. The battery 13 includes a plurality of battery cells 130 (only one is shown in the figure), and the battery can be repeatedly charged in a cyclic and rechargeable manner.

[0039] In this embodiment, the battery 13 includes a positive electrode sheet, a negative electrode sheet, a separator and an electrolyte. The positive electrode sheet includes a positive current collector and a positive active material layer coated on the positive current collector. The positive active material layer includes a positive active material, a binder and a conductive agent. The positive active material includes a mixture of lithium manganese oxide (Li2MnO4) and LiMO, wherein the chemical formula of LiMO is: Li x Co y Ni z M 1-y-z O b-a X b . Wherein, M is selected from at least one of boron (B), magnesium (Mg), aluminum (Al), silicon (Si), phosphorus (P), sulfur (S), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), yttrium (Y), zirconium (Zr), molybdenum (Mo), silver (Ag), barium (Ba), tungsten (W), indium (In), tin (Sn), lead (Pb) and antimony (Sb). In some embodiments, the value ranges of x, y, z, a and b are: 0.8<x≤1.2, 0≤y≤0.5, 0.5≤z≤1.0, 0≤a≤1.0 and 1.8≤b≤2.2, respectively.

[0040] In this embodiment, the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer coated on the negative electrode current collector, the negative electrode active material layer includes a negative electrode active material and a binder, and the negative electrode active material is a carbon material or a non-carbon material. The carbon material can be natural graphite, artificial graphite, etc. The non-carbon material can be a transition metal (Sn / Sb), spinel type (Li4Ti5O 12 , LTO), one or more combinations of tin-based compounds and silicon-based compounds. It should be noted that in the following embodiments, carbon materials are used as the negative electrode active material for illustration.

[0041] In this embodiment, the electrolyte includes a solvent and a lithium salt. The solvent includes one or several of dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), ethyl propyl carbonate (EPC), ethyl butyl carbonate (EBC), dipropyl carbonate (DPC), ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), γ-butyrolactone (γ-BL), vinylene carbonate (VC), and propylene sulfite (PS); the lithium salt includes one or several of lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium hexafluoroarsenate (LiAsF6), lithium perchlorate (LiClO4), and lithium trifluoromethylsulfonate (CF3SO3Li).

[0042] In this embodiment, the acquisition device 14 is used to collect the voltage of the battery 13 and the charging current of the battery 13. In this embodiment, the acquisition device 14 is used to collect the voltage of the battery cell of the battery 13. In this embodiment, the acquisition device 14 is an analog-to-digital converter. It is understandable that the acquisition device 14 can also be other voltage acquisition devices and current acquisition devices. The timer 15 is used to record the length of time that the battery cell 130 of the battery 13 is in a static state. It is understandable that the electric device 100 can also include other devices, such as a pressure sensor, a light sensor, a gyroscope, a hygrometer, an infrared sensor, etc.

[0043] See also Figure 2 , Figure 2 This is a flow chart of a method for extending battery life according to an embodiment of the present application. The method for extending battery life is applied to a battery of an electric device. The method for extending battery life comprises the following steps:

[0044] Step S20: when the electric device is in a stationary state for a first preset time t1 and the voltage V1 of any one of the plurality of battery cells is within a first preset voltage range, the battery is discharged through the current I0.

[0045] In this embodiment, for a battery whose cathode chemical system is an LMO system, the LMO system has the problem of Mn dissolution during storage (high temperature / normal temperature), and Mn dissolution will destroy the anode SEI (solid electrolyte interphase) film of the battery and deposit on the anode, which is easy to cause the capacity loss of the battery. For example, when the voltage of any one of the multiple battery cells 130 in the battery 13 reaches a preset voltage (for example, 3.9V) and the time for which the electric device 100 is in a static state reaches the first preset time length t1, the structure of the battery 13 will be unstable, resulting in a loss of capacity of the battery 13, so that the battery life of the battery 13 decreases rapidly. In order to avoid the capacity loss of the battery 13, the present application discharges the battery cell 130 of the battery 13 through the self-discharge strategy of the BMS without changing the chemical system of the battery 13, reduces the probability of storage capacity loss of the battery 13 at the preset voltage, prolongs the service life of the battery cell 130, and thus prolongs the battery life of the battery 13.

[0046] In this embodiment, the operating status of the electric device 100 can be automatically monitored by the BMS. When it is detected that the electric device 100 is in a stationary state, the timer 15 is controlled to record the first preset time length that the electric device 100 is in the stationary state, and the acquisition device 14 is controlled to collect the voltage of each battery cell 130 in the multiple battery cells 130 to obtain multiple voltage values; when the BMS determines that any one of the multiple voltage values ​​is within the first preset voltage range, the BMS controls the battery 13 to start the discharge function, and the discharge current is I0.

[0047] In this embodiment, the first preset time length is less than or equal to 8 days, that is, the first preset time length t1 satisfies 0d<t1≤8d.

[0048] In this embodiment, the first preset voltage range is greater than or equal to 3.1V and less than or equal to 3.9V.

[0049] In this embodiment, the current I0 is greater than 0 mA and less than or equal to 500 mA. In other embodiments, the current I0 is greater than or equal to 10 mA and less than or equal to 300 mA. In other embodiments, the current I0 is greater than or equal to 20 mA and less than or equal to 200 mA.

[0050] It should be noted that when the electric device 100 is in a stationary state, it means that the battery 13 is in a stationary state, that is, the battery 13 is neither charged nor discharged.

[0051] Step S21: When the electric device 100 is in a non-stationary state or the voltage V2 of any one of the multiple battery cells 130 is less than or equal to any voltage value in a second preset voltage range, stop discharging the battery 13, wherein V1>V2, and 0.02V≤V1-V2≤1.1V.

[0052] In some other embodiments, 0.2V≤V1-V2≤1.0V.

[0053] In this embodiment, in order to avoid discharging all the power in the battery 13 and bringing adverse effects to the battery 13. When the electric device 100 meets the non-stationary state, or when the voltage V2 of any one of the multiple battery cells 130 meets the preset conditions, the battery 13 is stopped from being discharged. Specifically, the BMS continuously monitors the operating state of the electric device 100, and controls the acquisition device 14 to continuously acquire the voltage of each battery cell 130 in the multiple battery cells 130 to obtain multiple voltage values. If the electric device 100 is in a non-stationary state, the battery 13 is stopped from being discharged. The non-stationary state includes the electric device 100 being in a charging state or a riding state. If any voltage value V2 among the multiple voltage values ​​is less than or equal to any voltage value in the second preset voltage range, the battery 13 is stopped from being discharged.

[0054] In this embodiment, the second preset voltage range is greater than or equal to 2.8V and less than 3.1V.

[0055] It should be noted that after the battery 13 is self-discharged, the voltage V2 of the battery cell 130 and the voltage V1 of the battery cell 130 before the battery 13 is self-discharged satisfy the following conditions: V1>V2, and 0.02V≤V1-V2≤1.1V.

[0056] In some other embodiments, after step S21, the BMS continuously monitors the operating status of the electric device, and when the electric device is stationary, the above steps S20 and S21 are re-executed.

[0057] See also Figure 3 , Figure 3 This is a flow chart of a method for extending battery life according to another embodiment of the present application. The method for extending battery life is applied to a battery of an electric device. The method for extending battery life comprises the following steps:

[0058] Step S30: when the electric device 100 is in a stationary state for a second preset time t2 and the voltage V3 of any one of the plurality of battery cells 130 is within a third preset voltage range, the battery 13 is discharged through the current I0.

[0059] In this embodiment, the BMS continuously monitors the operating state of the electric device 100, and controls the acquisition device 14 to continuously acquire the voltage of each battery cell 130 in the multiple battery cells 130. When the voltage of any one of the multiple battery cells 130 in the battery 13 is greater than the preset voltage (for example, 3.9V), the battery 13 may not be in an unstable state, and the battery 13 does not need to be self-discharged at this time. However, if it is detected that the electric device 100 is in a stationary state for a second preset time t2 and the voltage V3 of any one of the multiple battery cells 130 is in the third preset voltage range, the BMS will start the self-discharge strategy for the battery. Therefore, the BMS controls the battery 13 to self-discharge, and the discharge current is I0.

[0060] In this embodiment, the third preset voltage range is greater than 3.9V and less than or equal to 4.1V.

[0061] Step S31: When the electric device 100 is in a non-stationary state or the voltage V4 of any one of the multiple battery cells 130 is less than or equal to any voltage value in the second preset voltage range, stop discharging the battery 13, wherein V3>V4, and 0.8V≤V3-V4≤1.5V.

[0062] In some other embodiments, 1.0V≤V3-V4≤1.3V.

[0063] Similarly, after the battery 13 is self-discharged, in order to avoid discharging all the electricity in the battery 13, it is necessary to stop discharging the battery 13. Specifically, the BMS continuously monitors the operating status of the electric device 100, and controls the acquisition device 14 to continuously collect the voltage of each battery cell 130 in the multiple battery cells 130 to obtain multiple voltage values. If the electric device 100 is in a non-stationary state, stop discharging the battery 13. Or if the voltage V4 of any one of the multiple battery cells 130 is less than or equal to any voltage value in the second preset voltage range, stop discharging the battery 13.

[0064] It should be noted that after the battery 13 is self-discharged, the voltage V4 of the battery cell 130 and the voltage V3 of the battery cell 130 before the battery 13 is self-discharged satisfy the following conditions: V3>V4, and 0.8V≤V3-V4≤1.5V.

[0065] In some other embodiments, after step S31, the BMS continuously monitors the operating status of the electric device, and when the electric device is stationary, the above steps S30 and S31 are re-executed.

[0066] In order to make the purpose, technical solution and advantages of the present application more clear, the following is a further detailed description of the method for extending the battery life of the present application in combination with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present application and are not used to limit the present application.

[0067] Example 1

[0068] The positive electrode sheet, negative electrode sheet, separator and electrolyte of the battery 13, and the battery cell 130 are prepared by the following method:

[0069] 1. Preparation of positive electrode sheet

[0070] Lithium nickel cobalt manganese oxide, lithium manganese oxide, conductive carbon black, carbon nanotubes, and polyvinylidene fluoride are dissolved in N-methylpyrrolidone solution at a weight ratio of 9.6:86.4:0.8:0.8:2.4 to form a positive electrode slurry. Aluminum foil is used as a positive electrode current collector (16 μm), and the positive electrode slurry is coated on the positive electrode current collector. After drying, cold pressing, and cutting procedures, a positive electrode sheet is obtained.

[0071] 2. Preparation of negative electrode sheet

[0072] Artificial graphite, styrene-butadiene rubber and sodium carboxymethyl cellulose are dissolved in deionized water at a weight ratio of 97.7:1.0:1.3 to form a negative electrode slurry. Copper foil is used as a negative electrode current collector, and the negative electrode slurry is applied to the negative electrode current collector. After drying, cold pressing and cutting procedures, a negative electrode sheet is obtained.

[0073] 3. Preparation of electrolyte

[0074] In an environment where the water content is less than 10 ppm, lithium hexafluorophosphate and a non-aqueous organic solvent are prepared in a weight ratio of 10:90 to form an electrolyte. The non-aqueous organic solvent is prepared by a weight ratio of ethylene carbonate (EC): diethyl carbonate (DEC): propylene carbonate (PC): propyl propionate: vinylene carbonate (VC) of 20:30:20:28:2.

[0075] 4. Preparation of isolation membrane

[0076] A single layer of polypropylene (PP) is selected as the isolation film.

[0077] 5. Preparation of battery cells

[0078] The negative electrode sheet, the positive electrode sheet, and the separator are stacked in order, so that the separator is between the positive electrode sheet and the negative electrode sheet to play a role of isolation, and then wound into an electrode assembly. The electrode assembly is then packed into an aluminum-plastic film packaging bag, and after dehydration at 80°C, a dry electrode assembly is obtained. The electrolyte is then injected into the dry electrode assembly, and after vacuum packaging, standing, forming, shaping and other processes, the preparation of the battery cell is completed.

[0079] The specific process of using the method for extending the battery life of the battery 13 provided in the embodiment of the present application includes: the BMS automatically monitors the operating status of the electric device 100. If it is detected that the electric device 100 is in a static state (i.e. not riding / not charging), the BMS controls the timer 15 to record the first preset time length that the electric device 100 is in the static state. If the first preset time length is greater than or equal to zero, and the voltage of one of the multiple battery cells 130 is 3.88V, the BMS controls the battery 13 to start the discharge function, and the discharge current is 5mA; the BMS continuously monitors the time that the electric device 100 is in a static state and the voltage of the battery cell. If the voltage of any battery cell 130 is ≥3.1V, the self-discharge is stopped. In this way, the following can be obtained: Figure 4 The battery life curve of the battery 13 after adopting the method for extending the battery life of the battery 13 provided by the embodiment of the present application is shown. Compared with the battery life curve of the battery 13 without adopting the method for extending the battery life of the battery 13 provided by the embodiment of the present application, after the battery 13 is self-discharged by a 5mA current, when the life of the battery 13 decays to 70%, the method provided by the embodiment of the present application can increase the battery life of the battery 13 by 6%. Specifically, after the battery 13 is self-discharged by a 5mA current (I0), it takes 3.18 years for the life of the battery 13 to decay to 70%; while when the self-discharge is not turned on, it takes 3 years for the life of the battery 13 to decay to 70%. It can be seen that the method provided by the embodiment of the present application can increase the battery life of the battery 13 by (3.18-3.0) / 3.0=6%.

[0080] Example 2

[0081] The positive electrode sheet, negative electrode sheet, separator and electrolyte of the battery 13, and the battery cell 130 are prepared by the following method:

[0082] 1. Preparation of positive electrode sheet

[0083] Nickel cobalt manganese, lithium iron phosphate, lithium manganate, conductive carbon black, carbon nanotubes, and polyvinylidene fluoride are mixed in a weight ratio of 28.8:28.8:38.4:0.8:0.6:2.4 (corresponding to a ratio of nickel cobalt manganese: lithium iron phosphate: lithium manganate of 3:3:4), and the preparation process is the same as in Example 1.

[0084] 2. Preparation of negative electrode sheet

[0085] Artificial graphite, Si, styrene-butadiene rubber and sodium carboxymethyl cellulose were mixed in a weight ratio of 92.8:4.9:1.0:1.3 (corresponding to a ratio of artificial graphite:Si of 95:5), and the preparation process was the same as in Example 1.

[0086] 3. The preparation process of the electrolyte is the same as that of Example 1.

[0087] 4. Preparation of isolation membrane

[0088] A single layer of polyethylene (PE) is selected as the isolation membrane, and ceramic is coated on one side.

[0089] 5. The preparation process of the battery cell is as described in Example 1.

[0090] The specific process of the method for extending the battery life of the battery 13 provided by the embodiment of the present application is as shown in Example 1, wherein, when the second preset time length when the electric device 100 is in a static state is recorded as 90 days and the voltage of one of the multiple battery cells 130 is 3.95V, the BMS controls the battery 13 to start the discharge function, and the discharge current is 10mA; the BMS continuously monitors the static time of the electric device 100 and the voltage of the battery cell, and stops self-discharge if the voltage of any battery cell 130 is ≥3.1V. In this way, it can be obtained as follows Figure 5 The battery life comparison is shown. Specifically, after the battery 13 is self-discharged by a 10mA current (I0), it takes 3.69 years for the life of the battery 13 to decay to 50%; while when the self-discharge is not turned on, it takes 4.99 years for the life of the battery 13 to decay to 50%. It can be seen that the method provided in the embodiment of the present application can increase the battery life of the battery 13 by (4.99-3.69) / 3.69=35%.

[0091] Example 3

[0092] The positive electrode sheet, negative electrode sheet, separator and electrolyte of the battery 13, and the battery cell 130 are prepared by the following method:

[0093] 1. The preparation process of the positive electrode plate is as described in Example 1, wherein the lithium iron phosphate, lithium manganese oxide, conductive carbon black, carbon nanotubes, and polyvinylidene fluoride that form the positive electrode slurry are in a weight ratio of 29.0:68.0:0.8:0.8:1.4, and the aluminum foil used as the positive electrode current collector is 10 μm.

[0094] 2. The preparation process of the negative electrode plate is as described in Example 1, wherein the weight ratio of natural graphite, artificial graphite, styrene-butadiene rubber and sodium carboxymethyl cellulose forming the negative electrode slurry is 30:67.7:1.0:1.3.

[0095] 3. The preparation process of the electrolyte is the same as in Example 1, wherein the weight ratio of lithium hexafluorophosphate and non-aqueous organic solvent forming the electrolyte is 9:91.

[0096] 4. Preparation of isolation membrane

[0097] A three-layer composite isolation membrane of polypropylene / polyethylene / polypropylene is selected, and ceramic is coated on one side.

[0098] 5. The preparation of the battery cell is the same as that of the battery cell in Example 1.

[0099] The specific process of the method for extending the battery life of the battery 13 provided by the embodiment of the present application is referred to in the embodiment, wherein, when the second preset time length when the electric device 100 is in a static state is recorded as 15 days and the voltage of one of the multiple battery cells 130 is collected to be ≤3.95V, the BMS controls the battery 13 to start the discharge function, and the discharge current is 5mA; the BMS continuously monitors the static time of the electric device 100 and the voltage of the battery cell, and stops self-discharge if the voltage of any battery cell 130 is ≥3.75V. In this way, it can be obtained as follows Figure 6 The battery life comparison is shown. Specifically, after the battery 13 is self-discharged by a 5mA current (I0), it takes 4.66 years for the battery 13 to decay to 50% of its life; while when the self-discharge is not turned on, it takes 5.01 years for the battery 13 to decay to 50%. It can be seen that the method provided in the embodiment of the present application can increase the battery life of the battery 13 by (5.01-4.66) / 4.66=7.5%.

[0100] Example 4

[0101] The positive electrode sheet, negative electrode sheet, separator and electrolyte of the battery 13, and the battery cell 130 are prepared by the following method:

[0102] 1. Preparation of positive electrode sheet: Lithium manganate, conductive carbon black, carbon nanotubes, and polyvinylidene fluoride are dissolved in N-methylpyrrolidone solution at a weight ratio of 19.2:76.8:0.8:0.6:2.4 to form positive electrode slurry, wherein the preparation process is the same as that of Example 2.

[0103] 2. Preparation of negative electrode sheet The negative electrode sheet is prepared as in Example 1.

[0104] 3. Preparation of electrolyte The electrolyte was prepared as in Example 1.

[0105] 4. Preparation of isolation membrane.

[0106] A three-layer composite release film of polypropylene / polyethylene / polypropylene is selected, and ceramic is coated on one side.

[0107] 5. The preparation of the battery cell is the same as that of the battery cell in Example 1.

[0108] The specific process of the method for extending the battery life of the battery 13 provided by the embodiment of the present application is as shown in Example 1, wherein, after recording the first preset time that the electric device 100 is in a static state, which is 6 days, and collecting that the voltage of one of the multiple battery cells 130 is 3.79V, the BMS controls the battery 13 to start the discharge function, and the discharge current is 10mA; the BMS continuously monitors the static time of the electric device 100 and the voltage of the battery cell, and stops self-discharge if the voltage of any battery cell 130 is ≥3.1V. In this way, it can be obtained as follows Figure 7 The battery life comparison is shown. Specifically, after the battery 13 is self-discharged by a 10mA current (I0), it takes 3.306 years for the battery 13 to decay to 60% of its life; while when the self-discharge is not turned on, it takes 3.68 years for the battery 13 to decay to 60%. It can be seen that the method provided in the embodiment of the present application can increase the battery life of the battery 13 by (3.68-3.306) / 3.306=11.3%.

[0109] Please continue reading Figure 1 In this embodiment, the memory 11 may be an internal memory of the electric device 100, that is, a memory built into the electric device 100. In other embodiments, the memory 11 may also be an external memory of the electric device 100, that is, a memory externally connected to the electric device 100.

[0110] In some embodiments, the memory 11 is used to store program codes and various data, and to achieve high-speed and automatic access to programs or data during the operation of the electric device 100 .

[0111] The memory 11 may include a random access memory and may also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0112] In one embodiment, the processor 12 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor, or the processor may be any other conventional processor, etc.

[0113] If the program code and various data in the memory 11 are implemented in the form of a software functional unit and sold or used as an independent product, they can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, such as the steps in the method for extending battery life, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), etc.

[0114] It is understandable that the module division described above is a logical function division, and there may be other division methods in actual implementation. In addition, the functional modules in each embodiment of the present application may be integrated in the same processing unit, or each module may exist physically separately, or two or more modules may be integrated in the same unit. The above-mentioned integrated modules may be implemented in the form of hardware or in the form of hardware plus software functional modules.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application and are not intended to limit it. Although the present application has been described in detail with reference to the preferred embodiments, a person of ordinary skill in the art should understand that the technical solution of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present application.

Claims

1. A method for extending battery life, applied in an electric device, wherein the electric device comprises a battery, wherein the battery comprises a plurality of cells, wherein: The method comprises: When the electric device is in a stationary state for a first preset time t1 and the voltage V1 of any one of the plurality of battery cells is within a first preset voltage range, discharging the battery through a current I0; When the electric device is in a non-stationary state or the voltage V2 of any one of the multiple battery cells is less than or equal to any voltage value in a second preset voltage range, the battery is stopped from being discharged, wherein V1>V2, and 0.02V≤V1-V2≤1.1V, the first preset voltage range is greater than or equal to 3.1V and less than or equal to 3.9V; the second preset voltage range is greater than or equal to 2.8V and less than 3.1V.

2. The method for extending battery life according to claim 1, characterized in that: 0 days<t1≤8 days.

3. The method for extending battery life as claimed in claim 1, characterized in that: The method further comprises: When the electric device is in a stationary state for a second preset time t2 and the voltage V3 of any one of the plurality of battery cells is within a third preset voltage range, discharging the battery through the current I0; When the electric device is in a non-stationary state or the voltage V4 of any one of the multiple battery cells is less than or equal to any voltage value in the second preset voltage range, discharging the battery is stopped, wherein V3>V4, and 0.8V≤V3-V4≤1.5V.

4. The method for extending battery life according to claim 3, characterized in that: The third preset voltage range is greater than 3.9V and less than or equal to 4.1V.

5. The method for extending battery life according to claim 3, characterized in that: 8 days ≤ t2 ≤ 365 days.

6. The method for extending battery life according to claim 1, wherein: The current I0 is greater than 0 mA and less than or equal to 500 mA.

7. The method for extending battery life according to claim 1, characterized in that: The battery comprises a positive electrode sheet, the positive electrode sheet comprises a positive electrode current collector and a positive electrode active material layer coated on the positive electrode current collector, the positive electrode active material layer comprises a positive electrode active material, and the positive electrode active material comprises a mixture of lithium manganate and LiMO, wherein the chemical formula of LiMO is: Li x Co y Ni z M 1-y-z O b-a X b , 0.8<x≤1.2, 0≤y≤0.5, 0.5≤z≤1.0, 1.8≤b≤2.2 and 0≤a≤1.

0.

8. An electric device, characterized in that: The electric device comprises: A battery, used to power the electric device, the battery comprising a plurality of cells; and A processor, configured to execute the method for extending battery life as claimed in any one of claims 1 to 7.

9. A storage medium having at least one computer instruction stored thereon, characterized in that: The instructions are loaded by a processor and used to execute the method for extending battery life according to any one of claims 1 to 7.

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