Low-temperature charging method and application of lithium ion battery

Abstract

The invention provides a low-temperature charging method and application of a lithium ion battery. The charging method comprises the steps that the environment temperature of the lithium ion battery is determined; dividing the space between the environment temperature and the rated temperature into a plurality of temperature intervals; determining the maximum multiplying power of safe discharging and charging of the battery in the plurality of temperature intervals; discharging for a preset time at a preset discharging rate less than or equal to the maximum discharging rate and charging for a preset time at a preset charging rate less than or equal to the maximum charging rate at the ambient temperature; repeatedly charging and discharging until the temperature of the lithium ion battery reaches an adjacent temperature interval; after reaching the adjacent temperature interval, repeatedly charging and discharging at the re-determined preset discharging rate and the re-determined preset charging rate, and reaching the next adjacent temperature interval until reaching the rated temperature; and charging at a rated charging rate. According to the low-temperature charging method and application of the lithium ion battery, the battery pack structure can be simplified, and the charging time can be shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a low-temperature charging method and application of lithium-ion batteries. Background Art

[0002] With the rapid development of smart grids, electric vehicles, portable electronics and other fields, secondary batteries, mainly lithium-ion batteries, have become one of the most widely used electrochemical energy storage devices. However, under low temperature conditions, the capacity and power characteristics of lithium-ion batteries are severely attenuated, and preheating is required to increase the output power and available capacity of lithium-ion batteries.

[0003] At present, the mainstream solution for low-temperature charging of battery systems is to heat up the battery through an additional heating system to restore its normal performance. For example, Chinese patent CN103427137B discloses a "low-temperature charging heating system and heating method for power batteries of pure electric vehicles", which uses the PTC outside the power battery for heating. Chinese patent CN110635183B discloses a "power battery system and a charging method for low-temperature charging optimized heating strategy", which uses an external PTC heating plate or heating film to heat the battery pack. The above heating method not only has the problems of poor heating uniformity and low heating efficiency, but also adds an additional heating auxiliary energy system, increases the extra weight of the battery pack, reduces the energy density of the battery pack, and increases production costs.

[0004] Chinese patent CN109659637B discloses a "low-temperature charging method for lithium-ion batteries with AC / DC superposition", which uses AC / DC superposition to charge and heat the battery. This method has the following problems: (1) The power consumption is the remaining power of the battery, resulting in a short heating time and low conversion efficiency. When the remaining power is small, the heating effect cannot be achieved; (2) There is a great risk of lithium deposition in the battery when AC / DC is used for heating and charging at the same time; (3) The heating process is complicated, which increases the complexity of the battery pack system circuit control, reduces the system efficiency, and prolongs the charging time. Summary of the invention

[0005] The present invention provides a low-temperature charging method and application of a lithium-ion battery. The low-temperature charging method and application of a lithium-ion battery provided by the present invention can simplify the battery pack structure, shorten the charging time, and improve the energy utilization rate.

[0006] In order to solve the above technical problems, the present invention provides a low temperature charging method for a lithium ion battery, which at least comprises:

[0007] Determine the ambient temperature of the lithium-ion battery;

[0008] Dividing the temperature region between the ambient temperature and the rated temperature of the lithium-ion battery into a plurality of temperature intervals;

[0009] Determining the maximum rate at which the lithium-ion battery can be safely discharged and charged within the plurality of temperature ranges;

[0010] At the ambient temperature, discharging the lithium-ion battery for a preset time at a preset discharge rate that is less than or equal to a maximum discharge rate, and charging the lithium-ion battery for a preset time at a preset charge rate that is less than or equal to a maximum charge rate;

[0011] Repeating charging and discharging the lithium-ion battery at the preset discharge rate and the preset charge rate until the temperature of the lithium-ion battery reaches the adjacent temperature range;

[0012] After reaching the adjacent temperature interval, repeatedly charging and discharging the lithium-ion battery at the re-determined preset discharge rate and preset charge rate to reach the next adjacent temperature interval until the rated temperature is reached; and

[0013] The lithium-ion battery is charged at the rated temperature and at a rated charging rate.

[0014] In an embodiment of the present invention, the preset time is 1 ms to 50 ms.

[0015] In one embodiment of the present invention, the preset discharge rate is 0.8 to 1 times the maximum discharge rate.

[0016] In one embodiment of the present invention, the preset charging rate is 0.8 to 1 times the maximum charging rate.

[0017] In an embodiment of the present invention, the temperature difference in the temperature range is 5°C to 10°C.

[0018] In one embodiment of the present invention, within the same temperature range, the preset discharge time of the lithium-ion battery at the preset discharge rate is equal to the preset charge time of the lithium-ion battery at the preset charge rate.

[0019] In an embodiment of the present invention, the preset time is equal in different temperature intervals.

[0020] In an embodiment of the present invention, the preset time is not equal in different temperature ranges.

[0021] The present invention also provides a lithium ion battery which is charged by the low temperature charging method described above.

[0022] The present invention also provides an electronic device, comprising the lithium-ion battery described above.

[0023] In summary, the present invention proposes a low-temperature charging method and application of a lithium-ion battery, which can quickly increase the temperature of the lithium-ion battery, thereby shortening the charging time. Because the battery energy consumed by heating is also relatively low, the heating efficiency is greatly improved, the energy utilization rate is improved, and users of new energy vehicles can get a better experience in winter or low temperature conditions. At the same time, the charging method provided by the present application does not require an additional heating source, which can simplify the battery pack structure, reduce production costs, and improve the performance of lithium-ion batteries as a whole.

[0024] Of course, any method of implementing the present invention does not necessarily need to achieve all of the advantages mentioned above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0026] Figure 1 The figure is a flow chart of a low temperature charging method for a lithium ion battery according to an embodiment of the present invention.

[0027] Figure 2 The figure is a flow chart of a low temperature charging method for a lithium ion battery in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0028] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0029] It should be understood that the present invention can be implemented in different forms and should not be interpreted as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to make the disclosure thorough and complete and to fully convey the scope of the present invention to those skilled in the art.

[0030] The technical solution of the present invention is further described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] See also Figure 1As shown, the present invention provides a low-temperature charging method for a lithium-ion battery, and the charging method at least includes steps S10-S70.

[0032] Step S10: Determine the ambient temperature of the lithium-ion battery.

[0033] Step S20: dividing the temperature region between the ambient temperature and the rated temperature of the lithium-ion battery into a plurality of temperature intervals.

[0034] Step S30: determining the maximum rate at which the lithium-ion battery can be safely discharged and charged within a plurality of temperature ranges.

[0035] Step S40: at ambient temperature, the lithium-ion battery is discharged for a preset time at a preset discharge rate that is less than or equal to the maximum discharge rate, and the lithium-ion battery is charged for a preset time at a preset charge rate that is less than or equal to the maximum charge rate.

[0036] Step S50: repeatedly charging and discharging the lithium-ion battery at a preset discharge rate and a preset charge rate until the temperature of the lithium-ion battery reaches an adjacent temperature range.

[0037] Step S60: After reaching the adjacent temperature interval, repeatedly charge and discharge the lithium-ion battery at the re-determined preset discharge rate and preset charge rate to reach the next adjacent temperature interval until the rated temperature is reached.

[0038] Step S70: charging the lithium-ion battery at a rated charge rate at a rated temperature.

[0039] See also Figure 1 As shown, in one embodiment of the present invention, in steps S10-S20, in a low temperature environment, when charging the lithium-ion battery, the lithium-ion battery is connected to the temperature monitoring system, and the ambient temperature of the lithium-ion battery is first confirmed by the temperature monitoring system. The ambient temperature is compared with the rated temperature of the lithium-ion battery in the battery management system, and a plurality of preset temperatures are selected in the temperature range between the ambient temperature and the rated temperature, and the ambient temperature and the rated temperature are divided into a plurality of temperature ranges. Among them, the temperature difference of the temperature range is, for example, 5°C to 10°C, which is not specifically limited by the present invention.

[0040] See also Figure 1As shown, in one embodiment of the present invention, in step S30, the maximum safe discharge rate Dmax and the maximum charge rate Cmax of the lithium-ion battery are determined in multiple temperature intervals. Among them, the maximum discharge rate Dmax is the maximum discharge rate of the lithium-ion battery in the temperature interval, the voltage does not exceed the protection voltage during the discharge process, and the maximum charge rate Cmax is the maximum charge rate of the lithium-ion battery in the temperature interval, the voltage does not exceed the protection voltage during the charging process. By determining the maximum discharge rate Dmax and the maximum charge rate Cmax of the lithium-ion battery in each temperature interval, the safety of the lithium-ion battery is ensured during the charging and discharging process.

[0041] See also Figure 1 As shown, in one embodiment of the present invention, in step S40, at the initial ambient temperature, the lithium-ion battery is discharged for a preset time at a preset discharge rate less than or equal to the maximum discharge rate, and the lithium-ion battery is charged for a preset time at a preset charge rate less than or equal to the maximum charge rate. The preset discharge rate is, for example, 0.8 to 1 times the maximum discharge rate Dmax, and the preset charge rate is, for example, 0.8 to 1 times the maximum charge rate Cmax. The preset times for charging and discharging are, for example, equal, for example, 1ms to 50ms. In other embodiments, the preset times for charging and discharging may also be unequal, that is, the frequency of charging and discharging has adjustable space to meet different charging processes.

[0042] See also Figure 1 As shown, in one embodiment of the present invention, in step S50, after selecting a preset discharge rate and a preset charge rate, the lithium-ion battery is repeatedly charged and discharged at the preset discharge rate and the preset charge rate until the temperature of the lithium-ion battery reaches an adjacent temperature range. In order to ensure energy efficiency, the discharge energy / charge energy is controlled to be between 5% and 15%, that is, through repeated rapid charging and discharging, the temperature of the lithium-ion battery is increased to reach the end value of the adjacent temperature range, and at the same time, the safety performance of the lithium-ion battery is ensured.

[0043] See also Figure 1As shown, in one embodiment of the present invention, in step S60, after the temperature of the lithium-ion battery monitored by the temperature monitoring system reaches the adjacent preset temperature, after the adjacent temperature interval, the lithium-ion battery is repeatedly charged and discharged with the preset discharge rate and preset charge rate re-determined at the maximum discharge rate Dmax and the maximum charge rate Cmax in the temperature interval, until the next adjacent temperature interval is reached, until the rated temperature is reached. In different temperature intervals, the preset time for charging and discharging may be equal or unequal. That is, in this embodiment, in different temperature intervals, repeated charging and discharging operations are performed with different preset discharge rates and preset charge rates, so that the temperature of the lithium-ion battery gradually rises to the rated temperature, wherein the rated temperature is the starting temperature for normal charging of the lithium-ion battery. In one embodiment of the present invention, the rated temperature is, for example, 10°C.

[0044] See also Figure 1 As shown, in one embodiment of the present invention, in step S70, after the temperature of the lithium-ion battery reaches the rated temperature, the lithium-ion battery is charged according to the rated charging rate required by the specific battery corresponding specification. The charging method provided by the present application can charge the lithium-ion battery at low temperature. At the same time, the original additional auxiliary energy heating methods such as PTC or heating film are abandoned, which not only simplifies the battery pack structure and reduces production costs, but also shortens the low-temperature charging time and improves energy utilization, which can enable new energy vehicle users to have a better experience in winter or low-temperature conditions.

[0045] See also Figure 2 As shown, in one embodiment of the present invention, the present invention provides a specific charging method for a lithium-ion battery, wherein, for example, the temperature between the ambient temperature of the lithium-ion battery and the rated temperature is divided into three temperature intervals, and the lithium-ion battery is charged, and the charging method includes at least steps S11-S21.

[0046] Step S11: discharging the lithium-ion battery at a first preset discharge rate for a first preset time at an ambient temperature.

[0047] Step S12: charging the lithium-ion battery at a first preset charging rate for a first preset time.

[0048] Step S13, repeating steps S11-S12 until the temperature of the lithium-ion battery rises from the ambient temperature to the first temperature.

[0049] Step S14: discharging the lithium-ion battery for a second preset time using a second preset discharge rate.

[0050] Step S15: charging the lithium-ion battery for a second preset time using a second preset charging rate.

[0051] Step S16, repeating steps S14-S15 until the temperature of the lithium-ion battery rises from the first temperature to the second temperature.

[0052] Step S17: discharging the lithium-ion battery for a third preset time using a third preset discharge rate.

[0053] Step S18: charging the lithium-ion battery at a third preset charging rate for a third preset time.

[0054] Step S19, repeat steps S17-S18 until the temperature of the lithium-ion battery rises from the second temperature to the third temperature.

[0055] Step S21, charging according to the rated charging rate required by the corresponding specification of the lithium-ion battery.

[0056] See also Figure 2 As shown, in one embodiment of the present invention, the ambient temperature is less than the first temperature, the first temperature is less than the second temperature, the second temperature is less than the third temperature, and the third temperature is, for example, the rated temperature, thereby dividing the temperature between the ambient temperature and the rated temperature into three temperature intervals. By monitoring the negative electrode potential, the critical rate under different discharge times is determined to take the maximum value of the negative electrode potential close to 0 but not less than 0, thereby determining the maximum discharge rate Dmax and the maximum charge rate Cmax between different temperature intervals under different preset times. Among them, in different temperature intervals, the first preset time, the second preset time and the third preset time for charging and discharging may be equal or unequal. By charging and discharging in different temperature intervals, the temperature of the lithium-ion battery is raised to the rated temperature, and then charged at the rated charge rate required by the corresponding specification of the lithium-ion battery to ensure the output power and available capacity of the lithium-ion battery.

[0057] The present invention also provides a lithium ion battery, including a positive electrode sheet, a separator, a negative electrode sheet and an electrolyte, wherein the separator is located between the positive electrode sheet and the negative electrode sheet, and the electrolyte is filled between the positive electrode sheet, the separator and the negative electrode sheet. Among them, the positive electrode sheet includes a positive electrode active material, and the positive electrode active material includes at least one of lithium iron phosphate, ternary materials, lithium manganate, lithium cobaltate or nickel cobalt manganate. The negative electrode sheet includes a negative electrode active material, and the negative electrode active material is selected from any one or a combination of at least two of artificial graphite, natural graphite, soft carbon, hard carbon, pure silicon, silicon oxide or silicon carbon compound. The separator is, for example, a polyethylene film (Polyethylene, PE), a polypropylene film (Polypropylene, PP), a glass fiber film, a polyethylene film or a composite film, and the electrolyte can be any suitable commercial electrolyte. The positive electrode sheet, the negative electrode sheet, the separator and the electrolyte are assembled into a single lithium ion battery, a battery module or a battery pack, etc., and then charged using the above-mentioned charging method. By controlling the preset time, preset discharge rate and preset charge rate, etc., the problem of serious attenuation of the capacity and power characteristics of lithium-ion batteries caused by low temperatures can be solved. The lithium-ion batteries can be charged at low temperatures to improve the output power and available capacity of the lithium-ion batteries.

[0058] Hereinafter, the present invention will be explained in more detail by citing examples, which should not be construed as limiting. Appropriate modifications may be made within the scope consistent with the gist of the present invention, all of which fall within the technical scope of the present invention.

[0059] Example 1

[0060] A lithium-ion battery is provided, wherein the rated capacity of the lithium-ion battery is 20Ah, the rated charge and discharge window is 2.5V to 3.65V, the primary protection voltage is 3.7V, and the secondary protection voltage is 3.8V. To ensure the safety of the battery, the protection device is triggered to stop charging when the voltage reaches 3.7V. The lithium-ion battery is fully discharged with a current of 1C and placed in an environment with an ambient temperature of -20°C for 8 hours to complete the battery cooling. Subsequent low-temperature charging is also carried out in an environment of -20°C.

[0061] Select a low temperature range of -20°C to 10°C, divide the temperature range into sections, select -20°C to -10°C as the first temperature range, -10°C to 0°C as the second temperature range, and 0°C to 10°C as the third temperature range. That is, -20°C is the ambient temperature, -10°C is the first temperature, 0°C is the second temperature, and 10°C is the third temperature.

[0062] The maximum charge and discharge rates in different temperature ranges were confirmed through gradient charge and discharge tests: in the first temperature range of 50ms, the maximum currents at which the lithium-ion battery can be safely discharged and charged are 1C and 0.9C respectively; in the second temperature range of 50ms, the maximum currents at which the battery can be safely discharged and charged are 1.2C and 1.1C respectively; in the third temperature range of 50ms, the maximum currents at which the battery can be safely discharged and charged are 1.6C and 1.4C respectively.

[0063] When the ambient temperature is -20℃, the battery is discharged with a current of 1C for 50ms, and then charged with a current of 0.9C for 50ms. The above discharge and charge cycles are repeated until the battery temperature rises from -20℃ to -10℃.

[0064] After the temperature of the lithium-ion battery rises to -10°C, the battery is discharged with a current of 1.2C for 50ms, and then charged with a current of 1.1C for 50ms. The above discharge and charge cycles are repeated until the battery temperature rises from -10°C to 0°C.

[0065] After the temperature of the lithium-ion battery rises to 0°C, the battery is discharged with a current of 1.6C for 50ms, and then charged with a current of 1.4C for 50ms. The above discharge and charge cycles are repeated until the battery temperature rises from 0°C to 10°C. After the temperature of the lithium-ion battery rises to 10°C, it is charged at the rated rate. During the charging process, the charging time, temperature rise rate, and battery energy consumed of the lithium-ion battery are recorded.

[0066] Example 2

[0067] A lithium-ion battery is provided, wherein the rated capacity of the lithium-ion battery is 20Ah, the rated charge and discharge window is 2.5V to 3.65V, the primary protection voltage is 3.7V, and the secondary protection voltage is 3.8V. To ensure the safety of the battery, the protection device is triggered to stop charging when the voltage reaches 3.7V. The lithium-ion battery is fully discharged with a current of 1C and placed in an environment with an ambient temperature of -20°C for 8 hours to complete the battery cooling. Subsequent low-temperature charging is also carried out in an environment of -20°C.

[0068] Select a low temperature range of -20°C to 10°C, divide the temperature range into sections, select -20°C to -10°C as the first temperature range, -10°C to 0°C as the second temperature range, and 0°C to 10°C as the third temperature range. That is, -20°C is the ambient temperature, -10°C is the first temperature, 0°C is the second temperature, and 10°C is the third temperature.

[0069] The maximum charge and discharge rates in different temperature ranges were confirmed through gradient charge and discharge tests: in the first temperature range of 5ms, the maximum currents at which the lithium-ion battery can be safely discharged and charged are 6.4C and 5.8C respectively; in the second temperature range of 5ms, the maximum currents at which the battery can be safely discharged and charged are 7.9C and 7.2C respectively; in the third temperature range of 5ms, the maximum currents at which the battery can be safely discharged and charged are 10.8C and 9.8C respectively.

[0070] When the ambient temperature is -20℃, the battery is discharged with a current of 6.4C for 5ms, and then charged with a current of 5.8C for 5ms. The above discharge and charge cycles are repeated until the battery temperature rises from -20℃ to -10℃.

[0071] After the temperature of the lithium-ion battery rises to -10°C, the battery is discharged with a current of 7.9C for 5ms, and then charged with a current of 7.2C for 5ms. The above discharge and charge cycles are repeated until the battery temperature rises from -10°C to 0°C.

[0072] After the temperature of the lithium-ion battery rises to 0°C, the battery is discharged with a current of 10.8C for 5ms, and then charged with a current of 9.8C for 5ms. The above discharge and charge cycles are repeated until the battery temperature rises from 0°C to 10°C. After the temperature of the lithium-ion battery rises to 10°C, it is charged at the rated rate. During the charging process, the charging time, temperature rise rate, and battery energy consumed of the lithium-ion battery are recorded.

[0073] Comparative Example 1

[0074] The lithium-ion battery is the same as in Example 1-2, and is first heated from -20°C to 10°C by a heating film, and then charged at a rated rate. During the charging process, the charging time, heating rate, and battery energy consumed of the lithium-ion battery are recorded.

[0075] Table 1. Charging performance of lithium ion batteries in Examples 1-2 and Comparative Example 1

[0076] Group Charging time (min) Heating rate (℃ / min) Consume battery power Example 1 16.2 1.85 2.7％ Example 2 12.2 2.45 1.2％ Comparative Example 1 66 0.45 8.6％

[0077] Please refer to Table 1, compared with Example 1-2, in a low temperature environment, in different temperature ranges, different preset charging rates and preset discharge rates are used for heavy discharge, so that the temperature of the lithium-ion battery is increased, thereby shortening the charging time, increasing the heating rate, and reducing the energy consumption of the lithium-ion battery. At the same time, as the preset time of charging and discharging is shortened, the charging time can be further reduced, the heating rate can be increased, and the energy consumption of the lithium-ion battery can be reduced, which is conducive to the charging of the lithium-ion battery in a low temperature environment. Compared with Example 1-2 and Comparative Example 1, relative to heating the lithium-ion battery with an external heating source, the charging method provided by the present application can greatly shorten the charging time and increase the heating rate of the lithium-ion battery. Because the battery energy consumed by heating is also relatively low, the heating efficiency is greatly improved, and the energy utilization rate is improved, which can enable new energy vehicle users to obtain a better experience in winter or low temperature conditions. At the same time, the present application does not require an additional heating source, can simplify the battery pack structure, reduce production costs, and improve the performance of lithium-ion batteries as a whole.

[0078] The present invention also provides an electronic device, the electronic device includes at least one of the above-mentioned lithium-ion batteries, and the lithium-ion battery is used to provide electrical energy. Among them, the electronic device can be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy and an electric tool, etc. In one embodiment of the present invention, the vehicle is, for example, a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. Spacecraft include airplanes, rockets, space shuttles and spacecrafts, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers, etc. And the electronic device also includes a temperature monitoring system connection to confirm the ambient temperature of the lithium-ion battery and the temperature during charging.

[0079] In summary, the present invention proposes a low-temperature charging method and application of lithium-ion batteries. By using different preset charging rates and preset discharge rates for re-discharging at low temperatures, the temperature of the lithium-ion battery can be quickly increased, thereby shortening the charging time. Since the battery energy consumed by heating is also relatively low, the heating efficiency is greatly improved, the energy utilization rate is improved, and new energy vehicle users can get a better experience in winter or low temperature conditions. At the same time, the present application does not require an additional heating source, which can simplify the battery pack structure, reduce production costs, and improve the performance of lithium-ion batteries as a whole.

[0080] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept, such as the technical solution formed by replacing the above features with the technical features with similar functions disclosed in this application (but not limited to). In addition to the technical features described in the specification, the remaining technical features are known technologies to those skilled in the art. In order to highlight the innovative features of the present invention, the remaining technical features will not be described in detail here.

Claims

1. A low temperature charging method for a lithium ion battery, characterized in that: At least the following steps are included: Determine the ambient temperature of the lithium-ion battery; Dividing the temperature region between the ambient temperature and the rated temperature of the lithium-ion battery into a plurality of temperature intervals; Determining the maximum rate at which the lithium-ion battery can be safely discharged and charged within the plurality of temperature ranges; At the ambient temperature, discharging the lithium-ion battery for a preset time at a preset discharge rate that is less than or equal to a maximum discharge rate, and charging the lithium-ion battery for a preset time at a preset charge rate that is less than or equal to a maximum charge rate; Repeating charging and discharging the lithium-ion battery at the preset discharge rate and the preset charge rate until the temperature of the lithium-ion battery reaches the adjacent temperature range; After reaching the adjacent temperature interval, repeatedly charging and discharging the lithium-ion battery at the re-determined preset discharge rate and preset charge rate to reach the next adjacent temperature interval until the rated temperature is reached; as well as The lithium-ion battery is charged at the rated temperature and at a rated charging rate.

2. The low temperature charging method for lithium ion batteries according to claim 1, characterized in that: The preset time is 1 ms to 50 ms.

3. The low temperature charging method for lithium ion batteries according to claim 1, characterized in that: The preset discharge rate is 0.8 to 1 times the maximum discharge rate.

4. The low temperature charging method for lithium ion batteries according to claim 1, characterized in that: The preset charging rate is 0.8 to 1 times the maximum charging rate.

5. The low temperature charging method for lithium ion batteries according to claim 1, characterized in that: The temperature difference in the temperature range is 5°C to 10°C.

6. The low temperature charging method for lithium ion batteries according to claim 1, characterized in that: In the same temperature range, the preset discharge time of the lithium-ion battery at the preset discharge rate is equal to the preset charge time of the lithium-ion battery at the preset charge rate.

7. The low temperature charging method for lithium ion batteries according to claim 6, characterized in that: In different temperature intervals, the preset time is equal.

8. The low temperature charging method for lithium ion batteries according to claim 6, characterized in that: In different temperature intervals, the preset time is not equal.

9. A lithium ion battery, characterized in that: Charging is performed using the low-temperature charging method described in any one of claims 1 to 8.

10. An electronic device, characterized in that: Includes the lithium ion battery as claimed in claim 9.

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