Charging and discharging management method

Abstract

The invention provides a charging and discharging management method. By implementing the charging and discharging management method provided by the embodiment of the invention, the electronic equipment can set the lower limit voltage of the battery to be higher than the theoretical lower limit voltage, and the lower limit voltage is continuously increased along with the promotion of battery circulation, so that the charging / discharging volume change rate of the silicon negative electrode is reduced as far as possible, and the service life of the battery is prolonged.

Description

A charging and discharging management method

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on August 23, 2022, with application number 202211014128.4 and application name “A Charging and Discharging Management Method”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of terminals, and in particular to a charge and discharge management method. Background Art

[0003] Due to people's demand for thinner and lighter electronic devices such as mobile phones and laptops, as well as longer battery life, and the demand for longer battery life in electric vehicles, the mass energy density and volume energy density of lithium-ion batteries are getting higher and higher. Increasing the gram capacity of positive and negative electrode materials is an important measure to improve battery life. At present, the gram capacity of graphite materials is close to the theoretical limit (372mAh / g), while the gram capacity of silicon (Si) is much higher than that of graphite (theoretical limit is 4200mAh / g). In addition, silicon has many advantages such as moderate lithium insertion and deintercalation potential, abundant reserves, low price, environmental protection and non-toxicity, and mature preparation technology. It is currently considered to be an ideal material to replace graphite as a negative electrode active material for batteries.

[0004] However, silicon has a significant volume effect. During repeated lithium insertion and extraction, the volume change rate caused by expansion and contraction can reach up to 400%. This results in particle pulverization, electrode film stripping, and repeated destruction and repair of the solid electrolyte interface (SEI) during charge and discharge, continuously consuming active lithium ions and forming a byproduct layer on the surface. This directly leads to a large cycle capacity decay rate and thickness expansion rate in silicon negative electrode batteries. As a result, their cycle life is unsatisfactory and cannot meet the requirements of electronic devices.

[0005] Summary of the Invention

[0006] In a first aspect, the present application provides a charge and discharge management method, which is applied to an electronic device, the electronic device including a battery, the method comprising: at a first moment, setting the lower limit voltage of the battery to a first value; when the voltage of the battery reaches the first value, the battery stops discharging; at a second moment, setting the lower limit voltage of the battery to a second value; at the second moment after the first moment, the second value is higher than the first value; when the voltage of the battery reaches the second value, the battery stops discharging.

[0007] By implementing the method provided in the first aspect, the electronic device can gradually increase the lower limit voltage of the battery, thereby suppressing the volume change rate of the battery, reducing the battery loss rate, and extending the battery life.

[0008] In some embodiments of the method provided in the first aspect, the first moment corresponds to a first battery cycle of the battery, the second moment corresponds to a second battery cycle of the battery, and the first battery cycle and the second battery cycle are different cycles.

[0009] By implementing the method provided in the above embodiment, the electronic device can increase the lower limit voltage of the battery based on the number of battery cycles.

[0010] In some embodiments of the method provided in the first aspect, the second battery cycle is a cycle subsequent to the first battery cycle.

[0011] By implementing the method provided in the above embodiment, the battery device can increase the battery's lower voltage limit every time a battery cycle begins. In this way, the electronic device can more flexibly adjust the battery's lower voltage limit, reduce the rate of battery capacity decay, and extend battery life.

[0012] In some embodiments of the method provided in the first aspect, the second battery cycle is separated from the first battery cycle by a first number of battery cycles.

[0013] Referring to the embodiment shown in Table 1, the electronic device can increase the lower limit voltage once every 200 battery cycles. This allows the electronic device to increase the lower limit voltage as the cycle progresses, reducing the rate of battery capacity decay and extending battery life, while also avoiding frequent upward adjustments, which is beneficial for energy conservation and extending the corresponding usage time of a single battery cycle.

[0014] In some embodiments of the method provided in the first aspect, the voltage difference between the second value and the first value corresponds to a first ratio of battery capacity.

[0015] By implementing the method provided in the above embodiment, each time the lower limit voltage is increased, the electronic device can determine the increase amount of the lower limit voltage according to the voltage difference corresponding to the fixed battery capacity loss amount.

[0016] Implementing the method provided in the first aspect, in some embodiments, within the first battery cycle, the capacity retention rate of the battery is a third value; within the second battery cycle, the capacity retention rate of the battery is a fourth value; the capacity retention rate is the ratio of the current total charge of the battery to the initial total charge; the third value and the fourth value are not equal.

[0017] By implementing the methods provided in the above embodiments, the electronic device can determine whether to increase the battery's lower voltage limit based on the battery's current capacity retention rate. Referring to the embodiment shown in Table 6, when the battery's capacity retention rate drops from 95% to 94%, the electronic device can determine to increase the lower voltage limit. This allows the electronic device to more flexibly adjust the battery's lower voltage limit based on the battery's current capacity retention rate.

[0018] In some embodiments of the method provided in the first aspect, the battery is preset with a first voltage value, which is the minimum value of the lower limit voltage of the battery; and the first value is greater than or equal to the first voltage value.

[0019] By implementing the method provided in the above embodiment, the electronic device can set the lower limit voltage to be higher than the theoretical minimum lower limit voltage when the battery starts to be used, thereby avoiding full discharge at the beginning, reducing the volume change rate of the battery, and delaying the battery loss rate.

[0020] In some embodiments of the method provided in the first aspect, the battery is preset with a second voltage value, the second voltage value is the maximum value of the lower limit voltage of the battery; and the second value is less than or equal to the second voltage value.

[0021] By implementing the method provided in the above embodiment, the electronic device does not excessively increase the lower limit voltage when increasing the lower limit voltage. When the lower limit voltage reaches the first voltage value, the electronic device no longer increases the lower limit voltage. This prevents the battery from experiencing issues such as low actual usable capacity and shortened battery life due to an increase in the lower limit voltage, thereby improving the user experience.

[0022] In some embodiments of the method provided in the first aspect, the negative electrode material of the battery comprises one or more of the following: carbon, silicon, tin, and germanium. When the negative electrode material of the battery comprises one or more of carbon, silicon, tin, and germanium, the electronic device can significantly suppress the volume change rate of the battery, thereby slowing the battery loss rate and improving the battery cycle life.

[0023] In a second aspect, the present application provides a charge and discharge management method, which is applied to an electronic device, the electronic device including a battery, the method including: at a third moment, setting the lower limit voltage of the battery to a fifth value; when the battery voltage reaches the fifth value, the battery stops discharging; at a fourth moment, setting the lower limit voltage of the battery to a sixth value; the fourth moment is after the third moment, and the sixth value is lower than the fifth value; when the battery voltage reaches the sixth value, the battery stops discharging.

[0024] By implementing the method provided in the second aspect, the electronic device can gradually lower the lower limit voltage of the battery so that when the battery capacity decays, the battery can maintain the initial discharge capacity during a single discharge process, thereby reducing the user's perception of battery capacity decay and improving the user experience.

[0025] In some embodiments of the method provided in the second aspect, the third moment corresponds to a third battery cycle of the battery, the fourth moment corresponds to a fourth battery cycle of the battery, and the third battery cycle and the fourth battery cycle are different cycles.

[0026] By implementing the method provided in the above embodiment, the electronic device can lower the lower limit voltage of the battery in units of battery cycle times.

[0027] In some embodiments of the method provided in the second aspect, the fourth battery cycle is a cycle subsequent to the third battery cycle.

[0028] By implementing the method provided in the above embodiment, the battery device can lower the battery's lower voltage limit once every battery cycle. In this way, the electronic device can more flexibly adjust the battery's lower voltage limit, reduce the rate of battery capacity decay, and extend battery life.

[0029] In some embodiments of the method provided in the second aspect, the fourth battery cycle is separated from the third battery cycle by a first number of battery cycles.

[0030] Referring to the embodiment shown in Table 8, the electronic device can lower the lower voltage limit once every 200 battery cycles. This allows the electronic device to lower the lower voltage limit as the cycle progresses, reducing the rate of battery capacity degradation and extending battery life, while also avoiding frequent lowering of the voltage limit, thereby saving energy and extending the battery life per cycle.

[0031] In some embodiments of the method provided in the second aspect, the voltage difference between the sixth value and the fifth value corresponds to a first ratio of battery capacity.

[0032] By implementing the method provided in the above embodiment, each time the lower limit voltage is lowered, the electronic device can determine the amount by which the lower limit voltage is lowered according to the voltage difference corresponding to the fixed battery capacity loss.

[0033] Implementing the method provided in the second aspect, in some embodiments, within the third battery cycle, the capacity retention rate of the battery is a seventh value; within the fourth battery cycle, the capacity retention rate of the battery is an eighth value; the capacity retention rate is the ratio of the current total charge of the battery to the initial total charge; the seventh value and the eighth value are not equal.

[0034] By implementing the method provided in the above embodiment, the electronic device can determine whether to lower the battery's lower voltage limit based on the battery's current capacity retention rate. For example, when the battery's capacity retention rate drops from 95% to 94%, the electronic device can determine to lower the lower voltage limit. This allows the electronic device to more flexibly adjust the battery's lower voltage limit based on the battery's current capacity retention rate.

[0035] In some embodiments of the method provided in the second aspect, the battery is preset with a first voltage value, which is the minimum value of the lower limit voltage of the battery; and the sixth value is greater than or equal to the first voltage value.

[0036] When the lower limit voltage is lowered, the electronic device will not lower the lower limit voltage excessively. When the lower limit voltage reaches the first voltage value, the electronic device will no longer lower the lower limit voltage to avoid affecting the normal operation of the battery.

[0037] In some embodiments of the method provided in the second aspect, the battery is preset with a second voltage value, which is the maximum value of the lower limit voltage of the battery; and the fifth value is less than or equal to the second voltage value.

[0038] By implementing the method provided in the above embodiment, the electronic device will not set the lower limit voltage of the battery too high, thereby avoiding severely reducing the battery capacity at the beginning, reducing the battery life within a battery cycle, and affecting the user experience.

[0039] In some embodiments of the method provided in the second aspect, the negative electrode material of the battery comprises one or more of the following: carbon, silicon, tin, and germanium. When the negative electrode material of the battery comprises one or more of carbon, silicon, tin, and germanium, the electronic device can significantly suppress the volume change rate of the battery, thereby slowing the battery loss rate and improving the battery cycle life.

[0040] In a third aspect, the present application provides an electronic device comprising one or more processors and one or more memories; wherein the one or more memories are coupled to the one or more processors, and the one or more memories are used to store computer program code, and the computer program code comprises computer instructions. When the one or more processors execute the computer instructions, the electronic device executes the method described in the first aspect and any possible implementation of the first aspect, or executes the method described in the second aspect and any possible implementation of the second aspect.

[0041] In a fourth aspect, an embodiment of the present application provides a chip system, which is applied to an electronic device, and the chip system includes one or more processors, which are used to call computer instructions to enable the electronic device to execute the method described in the first aspect and any possible implementation of the first aspect, or execute the method described in the second aspect and any possible implementation of the second aspect.

[0042] In a fifth aspect, the present application provides a computer-readable storage medium comprising instructions. When the instructions are executed on an electronic device, the electronic device executes the method described in the first aspect and any possible implementation of the first aspect, or executes the method described in the second aspect and any possible implementation of the second aspect.

[0043] In a sixth aspect, the present application provides a computer program product comprising instructions, which, when the above-mentioned computer program product is run on an electronic device, enables the above-mentioned electronic device to execute the method described in the first aspect and any possible implementation of the first aspect, or execute the method described in the second aspect and any possible implementation of the second aspect.

[0044] It is understandable that the electronic device provided in the third aspect, the chip system provided in the fourth aspect, the computer storage medium provided in the fifth aspect, and the computer program product provided in the sixth aspect are all used to perform the methods provided in this application. Therefore, the beneficial effects that can be achieved can be referred to the beneficial effects of the corresponding methods and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] FIG1 is a schematic diagram showing the relationship between the state of charge and thickness of a silicon negative electrode battery provided in an embodiment of the present application;

[0046] FIG2 is a flow chart of a charge and discharge management method for extending battery life provided by the present application;

[0047] 3A-3B are schematic diagrams showing the effect of extending battery life provided by an embodiment of the present application;

[0048] FIG4 is a schematic diagram showing the effect of extending battery life corresponding to another charge and discharge management method provided in an embodiment of the present application;

[0049] FIG5 is a schematic structural diagram of an electronic device 10 provided in an embodiment of the present application. DETAILED DESCRIPTION

[0050] The terms used in the following embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0051] FIG1 is a schematic diagram showing the relationship between the state of charge and thickness of a silicon negative electrode battery (graphite-doped silicon negative electrode battery) provided in an embodiment of the present application.

[0052] As shown in Figure 1, the horizontal axis represents the state of charge (SOC) of the silicon anode battery. SOC = 0 indicates that the battery is uncharged. SOC = 100% indicates that the battery is fully charged. The process from SOC = 0 to SOC = 100% is the charging process; the process from SOC = 100% to SOC = 0 is the discharging process.

[0053] The vertical axis is the thickness of the silicon negative electrode battery. When SOC=0, the thickness of the silicon negative electrode battery is recorded as T L . T L ≠0. When SOC=A% (A% is a state of charge slightly higher than 0), the thickness of the battery is recorded as T A When SOC=1-A% (1-A% is a state of charge slightly lower than 100%), the thickness of the battery is recorded as T B When SOC=100%, the thickness of the battery is recorded as T U .

[0054] During the charging process, the thickness of the battery increases as the charge increases, that is, it expands. Correspondingly, during the discharge process, the thickness of the battery decreases as the charge decreases, that is, it shrinks. Most of the thickness changes during the battery charging and discharging process come from the thickness changes of the negative electrode. As a result, during the repeated lithium insertion and extraction process, the volume change rate caused by the expansion / contraction of the negative electrode is extremely high, which directly leads to the pulverization of the negative electrode particles, the stripping of the electrode, and the repeated destruction / repair of the SEI, which in turn seriously affects the cycle life of the silicon negative electrode battery.

[0055] SOC = 0 is the extreme value that the battery can reach during a reasonable discharge process. The battery voltage corresponding to SOC = 0 is V min . V min It can be called the theoretical lower limit voltage. During a reasonable discharge process, the battery voltage is not lower than the theoretical lower limit voltage. SOC = 100% is the extreme value that the battery can reach during a reasonable charging process. The battery voltage corresponding to SOC = 100% is V max . V max It can be called the theoretical upper limit voltage. Accordingly, during a reasonable charging process, the battery voltage is not higher than the theoretical upper limit voltage. That is, V min ~V max Reasonable operating voltage window for the battery.

[0056] As shown in Figure 1, in the actual charge and discharge process, if the lower limit voltage is set to V min (theoretical lower limit voltage), the upper limit voltage is set to V max (theoretical upper limit voltage), that is, fully charged and discharged, then after the charge / discharge is completed, the battery thickness change rate K1: K1=(T U -T L ) / T L

[0057] If the lower limit voltage is set to V min , the upper limit voltage is set to V b2 (SOC = 1-A%), that is, not fully charged (limited upper limit voltage), then, after the charge / discharge is completed, the battery thickness change rate K2: K2 = (T B -T L ) / T L

[0058] If the lower limit voltage is set to V b1 (SOC = A%), the upper limit voltage is set to V max , that is, not fully discharged (limited lower voltage), then, after the charge / discharge is completed, the thickness change rate of the battery is K3: K3=(T U -T A ) / T A

[0059] From the changing trend of the SOC curve shown in Figure 1, we can see that: K1>K2>K3

[0060] This means that under the full charge and discharge management strategy, the battery's charge / discharge volume change rate is the highest, followed by limiting the upper voltage limit (sacrificing A% of capacity). The lowest charge / discharge volume change rate is achieved under the lower voltage limit charge and discharge management strategy (also sacrificing A% of capacity).

[0061] The greater the charge / discharge volume change rate of the silicon negative electrode battery, the greater the negative electrode loss, and the shorter the battery cycle life (including capacity life and expansion life). In view of this, the present application provides a charge and discharge management method. By implementing the charge and discharge management method provided in the embodiment of the present application, the electronic device 10 can set the lower limit voltage of the battery to be higher than the theoretical lower limit voltage, and, as the battery cycle progresses, continuously increase the lower limit voltage, thereby reducing the charge / discharge volume change rate of the silicon negative electrode as much as possible and extending the battery life.

[0062] FIG2 is a flow chart of a charge and discharge management method for extending battery life provided by the present application.

[0063] S101: Determine the current cycle number of the battery.

[0064] In the initial fully charged state, the battery charge is 100%. When the battery supplies power to an external circuit, the battery voltage gradually decreases, referring to the SOC curve of the discharge stage in Figure 1.

[0065] After the battery is depleted, it stops supplying power to external circuits. From the user's perspective, the battery charge is now zero. At this point, the charging circuit is connected. The external circuit performs work on the battery, gradually increasing the battery voltage until the negative electrode reaches saturation charge, as shown in the SOC curve for the charging phase in Figure 1. From the user's perspective, the battery charge is now 100%.

[0066] The aforementioned process of one discharge followed by one charge, i.e., the process of the battery charge going from 100% to 0 and then back to 100% as shown in FIG1 , can be referred to as one battery cycle. A battery's entire lifecycle includes multiple battery cycles. The more battery cycles performed, the shorter the remaining life of the battery. In some embodiments, a battery cycle can also refer to the process of a battery reaching a single full charge or a single full discharge.

[0067] In an embodiment of the present application, when the electronic device 10 starts a new battery cycle, it can dynamically adjust the upper and lower voltage limits of the battery according to the number of battery cycles that have been executed, thereby avoiding excessive volume change rate of the battery and reducing battery loss.

[0068] The electronic device 10 may set a cycle interval for adjusting the lower limit voltage based on factors such as the number of battery cycles that have been performed and the current actual capacity of the battery.

[0069] The electronic device 10 can set cycle numbers 1 to n0 as the first cycle interval, cycle numbers n0+1 to n1 as the second cycle interval, cycle numbers n1+1 to n2 as the third cycle interval, and so on. The electronic device 10 can set M cycle intervals. Depending on the basis for dividing the cycle intervals, the number of battery cycles in different intervals can be the same or different.

[0070] When the electronic device 10 starts a new battery cycle, the electronic device 10 may confirm the current cycle number.

[0071] S102: When the current cycle number of the battery is between 1 and n0 (the first cycle interval), the electronic device 10 sets the lower limit voltage to V min (theoretical lower limit voltage), the upper limit voltage is set to V max (Theoretical upper limit voltage). Optionally, in the first cycle interval, the electronic device 10 may also set the lower limit voltage to V x , V x Higher than V min , in order to reduce battery loss and extend battery cycle life. The above theoretical lower limit voltage is also called the first voltage value.

[0072] As the number of cycles increases, S103: when the current number of cycles of the battery is between n0+1 and n1 (the second cycle interval), the electronic device 10 increases the lower limit voltage to V min +V0, the upper limit voltage is maintained at V max At this time, compared with the first cycle interval, the volume change rate of the battery in the second cycle interval is reduced, thereby reducing the battery capacity attenuation rate and thickness expansion rate, and extending the battery cycle life.

[0073] S104: When the current cycle number of the battery is between n1+1 and n2 (the third cycle interval), the electronic device 10 increases the lower limit voltage to V min +V0+V1, the upper limit voltage is maintained at V max S105: Similarly, as the number of cycles increases, the electronic device 10 gradually increases the lower limit voltage. In this way, while maintaining the battery capacity, the electronic device 10 can gradually reduce the battery capacity attenuation rate and thickness expansion rate, thereby extending the battery cycle life, thereby extending the user's usage time and improving the user experience.

[0074] 3A and 3B are schematic diagrams showing the effect of extending battery life provided by an embodiment of the present application.

[0075] The criterion for battery life is that the battery capacity reaches the minimum value C required to maintain normal operation of the battery. min , or the thickness of the battery expands to the maximum value T required to maintain normal operation of the battery max .

[0076] The greater the charge / discharge volume change rate of a silicon anode battery, the greater the battery loss, that is, the faster the battery capacity decays. As shown in Figure 1, the lower the lower limit voltage of a silicon anode battery, the greater the charge / discharge volume change rate. As the battery cycle number increases, the lower limit voltage gradually increases and the charge / discharge volume change rate gradually decreases. Correspondingly, the battery capacity decay rate gradually decreases.

[0077] As shown in Figure 3A, C0 represents the initial capacity of the battery, C min Indicates the minimum value of the capacity to maintain the normal operation of the battery, and the slope indicates the decay rate of the battery capacity. In the first cycle interval (1 to n0), the lower limit voltage of the battery is the lowest and the charge / discharge volume change rate is the highest. Therefore, the decay rate of the battery capacity is the largest, which is S0. If the method for charge and discharge management provided in the embodiment of the present application is not performed, the decay rate of the battery capacitance remains S0. At this time, the change of the battery capacity with the battery cycle is shown as the dotted line in Figure 3A. The total number of battery cycles of the battery is N.

[0078] If the charge and discharge management method provided in the embodiment of the present application is executed, after the battery cycle reaches the endpoint values ​​of the interval n0, n1, n2, etc., the electronic device 10 can gradually increase the lower limit voltage of the battery, reduce the charge / discharge volume change rate, and then gradually reduce the decay rate of the battery capacitance, such as S1, S2, S3, etc. At this time, the change of the battery capacity with the battery cycle is shown as the solid line in Figure 3A. The total number of cycles of the battery increases to N+N1, extending the cycle life of the battery.

[0079] As shown in Figure 3B, T0 represents the initial thickness of the battery, T max It represents the maximum value of the thickness of the battery cell that maintains the normal operation of the battery, and the slope represents the charge / discharge volume change rate of the battery. As shown in Figure 1: the lower the lower limit voltage of the battery, the greater the charge / discharge volume change rate. In the first cycle interval (1 to n0), the lower limit voltage of the battery is the lowest, and the charge / discharge volume change rate is the highest, which is P0. At this time, if the charge and discharge management method provided in the embodiment of the present application is not performed, the charge / discharge volume change rate of the battery remains P0. At this time, the change in the thickness of the battery with the battery cycle is shown as the dotted line in Figure 3B. The total number of battery cycles of the battery is N'.

[0080] If the method for gradually increasing the battery's lower voltage limit, as provided in the embodiments of this application, is followed, the battery's charge / discharge volume change rate gradually decreases, for example, P1, P2, and P3. At this point, the change in battery thickness over battery cycles is shown by the solid line in Figure 3B. The total number of battery cycles is N' + N2, extending the battery's cyclic expansion life.

[0081] In some embodiments, the electronic device 10 may set cycle intervals with different lower-limit voltages based on the number of battery cycles performed. Specifically, the electronic device 10 may set each cycle interval based on a fixed number of cycles. For example, the electronic device 10 may define 200 consecutive battery cycles as one cycle interval. For example, Table 1 shows a rule for adjusting the cycle interval and lower-limit voltage.

[0082] Table 1

[0083] The life of the battery is limited, so the cycle interval is also limited. At the same time, the increase in the lower limit voltage leads to a decrease in battery capacity. If the lower limit voltage is set too high, the battery capacity is too low, the battery's endurance is poor, and the battery needs to be charged frequently, which is not conducive to user use. Therefore, after a certain number of battery cycles have been executed, the subsequent cycles can be defined as a cycle interval, and the lower limit voltage of the battery will no longer be adjusted upward. For example, the cycle starting from the 601st cycle and thereafter can be defined as a cycle period. Starting from the 601st cycle, thereafter, the lower limit voltage of the battery is V min +300mV, the electronic device 10 no longer increases the lower limit voltage of the battery.

[0084] After determining the cycle interval, the electronic device 10 can determine the lower limit voltage of the battery cycle according to the cycle interval of the current cycle number. For example, when starting the first battery cycle, the electronic device 10 can set the lower limit voltage of the battery to V min , for example V min =3.0V, set the upper limit voltage to V max , for example V max =4.45V. During the battery discharge process, the voltage gradually decreases to V min Then, during battery charging, the voltage returns to V max Thereafter, during the 2nd, 3rd, ... to 200th battery cycles, the battery is kept at the above V min =3.0V, V max =4.45V for discharge and charge.

[0085] When the battery starts the 201st battery cycle, the electronic device 10 can increase the lower limit voltage of the battery. For example, the electronic device 10 can increase the lower limit voltage of the battery to 3.1V (V0=100mV). The electronic device 10 can keep the upper limit voltage unchanged. During the battery discharge process, when the battery voltage drops to 3.1V, the battery no longer discharges. Then, the battery can enter the charging process. During the charging process, the battery's own voltage returns to 4.45V. Thereafter, the battery enters the 202nd battery cycle and begins to discharge. During the 201st, 202nd... to 400th battery cycles, the battery is charged according to the above V min +V0=3.1V、V max =4.45V for discharge and charge.

[0086] When the battery starts the 401st battery cycle, the electronic device 10 continues to increase the lower limit voltage. For example, the electronic device 10 can increase the lower limit voltage of the battery to 3.2V (V1=100mV) while keeping the upper limit voltage unchanged. During the battery discharge process, when the battery voltage drops to 3.2V, the discharge is stopped. Then, the battery can enter the charging process. During the charging process, the battery's own voltage returns to 4.45V. Thereafter, the battery enters the 402nd battery cycle and begins to discharge. During the 401st, 402nd... to 600th battery cycles, the battery is charged according to the above V min +V0+V1=3.2V、V max =4.45V for discharge and charge.

[0087] In the above embodiment, the electronic device 10 sets the lower limit voltage of the battery to V min (3.0V), set the upper voltage limit to V max The moment when the electronic device 10 increases the lower limit voltage of the battery to 3.1V may be referred to as the first moment, and the moment when the electronic device 10 increases the lower limit voltage of the battery to 3.1V may be referred to as the second moment. The electronic device 10 may set the lower limit voltage at any time before the end of discharge of a cycle. The lower limit voltage 3.0V corresponding to the first moment may be referred to as the first value, and the lower limit voltage 3.1V corresponding to the second moment may be referred to as the second value. The first battery cycle corresponding to the first moment may be referred to as the first battery cycle, and the 201st battery cycle corresponding to the second moment may be referred to as the second battery cycle. The second battery cycle is 200 battery cycles apart from the first battery cycle. The above 200 battery cycles are the first number of battery cycles.

[0088] It is understood that the moment when the electronic device 10 sets the battery's lower voltage limit to 3.1V can be referred to as the first moment, and the moment when the electronic device 10 increases the battery's lower voltage limit to 3.2V can be referred to as the second moment. In this case, the lower voltage limit of 3.1V corresponding to the first moment can be referred to as the first value, and the lower voltage limit of 3.2V corresponding to the second moment can be referred to as the second value. The first battery cycle corresponding to the first moment can be referred to as the first battery cycle, and the 201st battery cycle corresponding to the second moment can be referred to as the second battery cycle.

[0089] As shown in FIG3A , the sooner the lower limit voltage is raised, the sooner the battery capacity decay rate can be reduced, thereby improving the battery cycle life as much as possible. Therefore, the electronic device 10 may also optionally raise the lower limit voltage after each battery cycle, thereby reducing the battery capacity decay rate in a more real-time manner and extending the battery life. See Table 2:

[0090] Table 2

[0091] As shown in Table 2, the voltage limit is adjusted once per battery cycle. Therefore, the increase should not be too high. Otherwise, after several or even dozens of battery cycles, the battery's lower voltage limit will be too high. Therefore, a rapid voltage increase will also lead to a rapid decrease in battery capacity. While this theoretically extends battery life, the user experience may be worse than the natural loss caused by volume effect.

[0092] Therefore, when implementing the adjustment strategy shown in Table 2, the increase in the lower limit voltage corresponding to one battery cycle is much smaller than the increase in the one cycle interval shown in Table 1. Preferably, the increase in the lower limit voltage corresponding to one battery cycle can be 1*0.3mV.

[0093] Similarly, increasing the lower limit voltage will result in a decrease in battery capacity. Therefore, in order to ensure the battery's power supply capacity and avoid the battery capacity being too small to affect the user experience (insufficient battery life, requiring frequent charging), the lower limit voltage cannot be increased indefinitely. Therefore, the electronic device 10 can also set a maximum value for the lower limit voltage. When the increase in the lower limit voltage reaches the above-mentioned maximum value, the electronic device 10 can stop increasing the lower limit voltage. For example, the above-mentioned maximum value can be 3.5V (where V min =3.0V). When (i-1)*0.3mV>0.5V, the electronic device 10 may stop increasing the lower limit voltage.

[0094] In the above embodiment, the kth battery cycle can be called the first battery cycle, 1≤k≤i, and the k+1th battery cycle can be called the second battery cycle. After the kth battery cycle begins, the electronic device sets the lower limit voltage to V minThe moment of +(k-1)*0.3mV can be called the first moment. After the k+1th battery cycle begins, the electronic device sets the lower limit voltage to V min The moment when +k*0.3mV can be called the second moment. min +(k-1)*0.3mV is the first value, V min +k*0.3mV is the second value. The highest value of the lower limit voltage (3.5V) can be called the second voltage value.

[0095] In the example shown in Table 1, the increment of the lower limit voltage between two adjacent cycle intervals is the same, for example, V0=V1=100mV. Optionally, the increment of the lower limit voltage can also be different, refer to Table 3:

[0096] Table 3

[0097] As shown in Table 3, V0 = 200mV and V1 = 100mV. The charge-discharge curves shown in Figure 1 indicate that the closer the lower limit voltage is to the theoretical lower limit voltage, the greater the battery's charge / discharge volume change rate. Therefore, when first increasing the lower limit voltage, the electronic device 10 can initially set a larger increase, then gradually reduce the increase. This can further slow the rate of battery capacity decay and extend the battery's cycle life.

[0098] Furthermore, when starting the first battery cycle, the electronic device 10 may also set the lower limit voltage to be higher than the theoretical lower limit voltage, that is, V x ≠V min , refer to Table 4:

[0099] Table 4

[0100] Among them, V x >V min For example, in V min =3.0V, V x It can be 3.1 V. In this way, starting from the first battery cycle, the battery is not fully charged and discharged, thereby avoiding the high volume change rate during the process of the voltage dropping to the theoretical lower limit voltage, further improving the battery cycle life.

[0101] In the example shown in Table 1, the increment of the lower limit voltage between two adjacent cycle intervals is the same, for example, V0 = V1 = 100mV. Optionally, the increment of the lower limit voltage can also be different, but the increment of capacity loss is kept the same, and the corresponding voltage is determined according to the capacity loss. Refer to Table 5:

[0102] Table 5

[0103] As shown in Table 5, in the first cycle interval (1st to 200th battery cycle), the electronic device 10 can set the lower limit voltage of the battery to V min . In the second cycle interval (201st to 400th battery cycle), the capacity loss is set to 1% to increase the lower limit voltage, which is Vmin+V(1% loss). Among them, V(1% loss) refers to the voltage corresponding to 1% of the battery capacity. The relationship between battery capacity and voltage is nonlinear. Each time the lower limit voltage is increased, the increment of the lower limit voltage corresponding to 1% of the capacity is not equal. The specific value can be determined according to the voltage-capacity SOC relationship in the initial charge and discharge curve. By analogy, the electronic device 10 can determine the lower limit voltage corresponding to the third and fourth cycle intervals after entering the third and fourth cycle intervals, thereby gradually reducing the volume change rate of charge / discharge and extending the battery cycle life.

[0104] In the embodiment of the present application, when the first value is V min The second value is V min When +V(1% loss), the voltage difference between the first value and the second value, namely V(1% loss), can be referred to as the voltage corresponding to the battery capacity of the first ratio.

[0105] As the battery charges and discharges, its capacity gradually decreases. Therefore, in other embodiments, the electronic device 10 can monitor the actual battery capacity in real time and adjust the cycle interval for the lower voltage limit based on the actual capacity. For example, every time the battery capacity decreases by 5%, the electronic device 10 can set a new cycle interval. For example, Table 6 shows another adjustment rule for the cycle interval and the lower voltage limit.

[0106] Table 6

[0107] The capacity retention rate refers to the ratio of the current battery capacity to the initial battery capacity. As shown in Table 3, the capacity retention rate of 100% to 95% can be demarcated as the first cycle interval, 95% to 90% (excluding 95%) as the second cycle interval, and so on. When the capacity retention rate is lower than 95%, the electronic device 10 can increase the lower limit voltage by 100mV to reduce the charge / discharge volume change rate of the battery and reduce the decay rate of the battery capacity. Similarly, the electronic device 10 can increase the lower limit voltage of the battery according to the actual battery capacity, thereby extending the battery cycle life. Similarly, considering the user experience, when the capacity retention rate is reduced to a preset value, the electronic device 10 no longer increases the lower limit voltage. For example, when the capacity retention rate is lower than 85%, the lower limit voltage of the battery is maintained at V min +300mV.

[0108] Similarly, in the method of adjusting the lower limit voltage according to the previous actual capacity shown in Table 6, the electronic device 10 can set the lower limit voltage of the first cycle interval to be higher than V min , and / or the electronic device 10 may also refer to the method shown in Table 2 to adjust the lower limit voltage more frequently, and / or the electronic device 10 may also refer to the method shown in Table 3 to gradually reduce the increase amount of the lower limit voltage.

[0109] By implementing the above charge and discharge management method, the electronic device 10 can adjust the lower limit voltage of the battery as the battery cycle progresses, control the charge / discharge volume change rate of the battery, thereby reducing the silicon negative electrode loss and extending the battery life.

[0110] In the above embodiment, when the third value is any value in the range of 100% to 95% and the fourth value is any value in the range of 95% to 90%, the first value is V min The second value is V min +100mV. When the third value is any value within the range of 95% to 90%, and the fourth value is any value within the range of 90% to 85%, the first value is V min +100mV, the second value is V min +200mV.

[0111] In some embodiments, the electronic device 10 can also adjust the upper limit voltage of the battery at the same time. Refer to Table 7:

[0112] Table 7

[0113] As shown in Table 7, the electronic device 10 can gradually reduce the upper limit voltage of the battery as the battery cycle progresses. This further reduces the battery volume change rate, thereby reducing the irreversible damage to the silicon negative electrode caused by volume expansion and contraction during charge and discharge, and extending the battery cycle life.

[0114] The adjustment amount and adjustment period of the lower limit voltage can refer to the specific rules of the upper limit voltage, which will not be repeated here. The electronic device 10 can adjust the upper limit voltage and the lower limit voltage synchronously.

[0115] Referring to the battery thickness-SOC curve shown in Figure 1: the thickness change of the silicon negative electrode battery caused by the same charge in the low voltage region is higher than that in the high voltage region. This means that, under the premise of losing the same capacity, the effect of suppressing the expansion / contraction of the silicon material by lowering the upper limit voltage is not as good as that of raising the lower limit voltage. Therefore, optionally, the frequency of adjusting the upper limit voltage of the electronic device 10 can be lower than the frequency of adjusting the lower limit voltage. For example, raising the lower limit voltage twice corresponds to adjusting the upper limit voltage once. Optionally, the voltage amount by which the electronic device 10 lowers the upper limit voltage once can be lower than the voltage amount by which the lower limit voltage is raised once.

[0116] In some embodiments, the electronic device 10 may also first set the lower limit voltage to be higher than the theoretical lower limit voltage V min , and then lower the lower limit voltage in subsequent battery cycles so that when the battery capacity decays, the battery can maintain the initial discharge capacity during a single discharge process, thereby reducing the user's perception of battery capacity decay and improving the user experience.

[0117] Table 8

[0118] For example, initially, the electronic device 10 may set the lower limit voltage of the battery to V Y , V Y >V min , for example V Y =3.5V; set the upper limit voltage to V max , for example V max =4.45V. In the first cycle, the battery is kept at the above V Y =3.5V, V max =4.45V for discharge and charge.

[0119] When the battery starts the 201st battery cycle, the electronic device 10 can lower the lower limit voltage of the battery. For example, the electronic device 10 can lower the lower limit voltage V Y Then, the battery is adjusted down to 3.4V. max =4.45V for discharge and charge. By analogy, the electronic device 10 can continuously lower the battery lower limit voltage based on the initially set lower limit voltage as the battery cycle progresses until the lower limit voltage reaches the theoretical lower limit voltage V min .

[0120] FIG4 is a schematic diagram showing the effect of extending battery life corresponding to the charge and discharge management method corresponding to Table 8 provided in the embodiment of the present application. C0 represents the initial capacity of the battery, C minrepresents the minimum capacity required to maintain normal battery operation, and the slope represents the rate of battery capacity decay. During full charge and discharge, the battery capacity gradually decreases as the negative electrode material loses power, with the number of battery cycles being N, as shown by the dotted line in Figure 4. If the charge and discharge management method shown in Table 8 is implemented, initially, the lower limit voltage is set higher than the theoretical lower limit voltage, resulting in the current actual battery capacity C1 being lower than C0. However, since the lower limit voltage is set higher than the theoretical lower limit voltage, the volume change rate of the battery during charge / discharge is lower than the volume change rate during full charge and discharge. When the number of cycles reaches n0, the electronic device 10 increases the lower limit voltage, allowing the battery capacity to be expanded based on the original decay. This allows the user to maintain the initial discharge capacity as much as possible during a single discharge, thereby reducing the user's perception of battery capacity decay and improving the user experience. Furthermore, using the method shown in Table 8, the battery's cycle life can be extended to N+N3.

[0121] Referring to the method shown in Table 2, in the embodiment of lowering the lower limit voltage (Table 8), the electronic device 10 may also lower the lower limit voltage of the battery each time a new battery cycle starts. Referring to the method shown in Table 3, in the embodiment of lowering the lower limit voltage, the amount of reduction of the lower limit voltage each time the electronic device 10 lowers the lower limit voltage may also be different. Referring to the method shown in Table 5, the electronic device 10 may determine the above-mentioned reduction amount based on the capacity loss. Referring to the method shown in Table 6, the electronic device 10 may also determine the above-mentioned reduction amount based on the current capacity retention rate of the battery, etc., which will not be repeated here.

[0122] In the above embodiment, the electronic device 10 sets V Y The moment of V can be called the third moment. The electronic device 10 can set V at any time before the discharge end moment of the cycle. Y In the 201st battery cycle, the electronic device 10 sets V Y The moment of -100mV can be called the fourth moment. Correspondingly, V Y Can be called the fifth value, V Y -100mV can be called the sixth value. It can be understood that the electronic device 10 sets V Y The moment of -100mV can be called the third moment. Y The moment of -200mV can be called the fourth moment. Correspondingly, V Y -100mV can be called the fifth value, V Y -200mV may be referred to as the sixth value.

[0123] FIG5 is a schematic structural diagram of an electronic device 10 provided in an embodiment of the present application.

[0124] As shown in Figure 5, the electronic device 10 includes a processor 101, a USB interface 102, a battery 103, and a battery management module 104. It should be understood that the structure shown in the embodiment of the present invention does not constitute a specific limitation on the electronic device 10. In other embodiments of the present application, the electronic device 10 may include more or fewer components than shown, or combine or separate certain components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0125] Processor 101 may include one or more processing units. For example, processor 101 may include an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a digital signal processor (DSP), a baseband processor, and the like. The different processing units may be independent devices or integrated into one or more processors. The controller may generate operation control signals based on instruction opcodes and timing signals to control instruction fetching and execution. Processor 101 may also include a memory for storing instructions and data.

[0126] The USB interface 102 is an interface that complies with USB standards, and may be a Mini USB interface, a Micro USB interface, a USB Type C interface, etc. The USB interface 102 can be used to connect a charger to charge the electronic device 10, and can also be used to transfer data between the electronic device 10 and peripheral devices.

[0127] It is understood that the interface connection relationship between the modules illustrated in the embodiment of the present invention is merely an illustrative illustration and does not constitute a structural limitation on the electronic device 10. In other embodiments of the present application, the electronic device 10 may also adopt a different interface connection method from the above embodiment, or a combination of multiple interface connection methods.

[0128] The negative electrode material of battery 103 is a material with a significant volume effect, such as silicon, tin (Sn), or germanium, as well as a mixed negative electrode composed of these materials and graphite. For example, battery 103 can be a lithium battery with a silicon negative electrode (graphite doped with silicon). Battery 103 can power other modules of electronic device 10, such as the processor, to maintain the normal operation of electronic device 10. After the stored energy of battery 103 is exhausted, battery 103 can receive charging input from a charger via USB port 102, store the energy, and then continue to power electronic device 10.

[0129] The battery management module 104 connects the USB interface 102, the battery 103, and the processor 101. The battery management module 104 can charge the battery 103 while also powering the electronic device. The battery management module 104 is configured to receive charging input from a charger. The battery management module 104 receives input from the battery 103 to power other modules of the electronic device 10, such as the processor 101. The battery management module 104 can also monitor parameters such as battery capacity, battery cycle count, and battery health status (leakage, impedance). In other embodiments, the battery management module 104 can also be located within the processor 101.

[0130] In an embodiment of the present application, the battery management module 104 can adjust the lower limit voltage and / or upper limit voltage of the negative electrode when monitoring the battery capacity and battery cycle number to reduce the volume change rate of the negative electrode material, reduce battery loss, and extend the battery cycle life.

[0131] In the embodiment of the present application, the electronic device 10 can be a mobile phone, a tablet computer, or a desktop computer, a laptop computer, a handheld computer, a notebook computer, an ultra-mobile personal computer (UMPC), a netbook, a cellular phone, a personal digital assistant (PDA), an augmented reality (AR) device, a virtual reality (VR) device, an artificial intelligence (AI) device, a wearable device, an in-vehicle device, a smart home device and / or a smart city device. The embodiment of the present application does not impose any special restrictions on the specific type of the electronic device 10.

[0132] As used in the specification and appended claims of the present application, the singular expressions "a", "an", "said", "above", "the" and "this" are intended to include plural expressions as well, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used in the present application refers to and includes any or all possible combinations of one or more of the listed items. As used in the above embodiments, the term "when..." can be interpreted to mean "if..." or "after..." or "in response to determining..." or "in response to detecting...". Similarly, the phrase "when determining..." or "if (stated condition or event) is detected" can be interpreted to mean "if determining..." or "in response to determining..." or "when (stated condition or event) is detected" or "in response to detecting (stated condition or event)", depending on the context.

[0133] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrations. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state hard disk).

[0134] Those skilled in the art will appreciate that all or part of the process steps in the above-described method embodiments can be implemented by a computer program instructing the relevant hardware. The program can be stored in a computer-readable storage medium. When executed, the program can include the process steps in the above-described method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM or random access memory (RAM), magnetic disks, or optical disks.

[0135] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A charge and discharge management method, characterized in that: Applied to an electronic device, the electronic device includes a battery, and the method includes: At a first moment, the lower limit voltage of the battery is set to a first value; when the voltage of the battery reaches the first value, the battery stops discharging; At a second moment, the lower limit voltage of the battery is set to a second value; the second moment is after the first moment, and the second value is higher than the first value; when the voltage of the battery reaches the second value, the battery stops discharging.

2. The method according to claim 1, characterized in that The first time corresponds to a first battery cycle of the battery, and the second time corresponds to a second battery cycle of the battery, and the first battery cycle and the second battery cycle are different cycles.

3. The method according to claim 2, characterized in that The second battery cycle is a next cycle to the first battery cycle.

4. The method according to claim 2, characterized in that The second battery cycle is separated from the first battery cycle by a first number of battery cycles.

5. The method according to claim 4, characterized in that The voltage difference between the second value and the first value corresponds to a first ratio of battery capacity.

6. The method according to claim 2, characterized in that In the first battery cycle, the capacity retention rate of the battery is a third value; in the second battery cycle, the capacity retention rate of the battery is a fourth value; the capacity retention rate is the ratio of the current total charge of the battery to the initial total charge; the third value is not equal to the fourth value.

7. The method according to claim 1, characterized in that The battery is preset with a first voltage value, which is the minimum value of the lower limit voltage of the battery; the first value is greater than or equal to the first voltage value.

8. The method according to claim 1, characterized in that The battery is preset with a second voltage value, which is the maximum value of the lower limit voltage of the battery; and the second value is less than or equal to the second voltage value.

9. The method according to claim 1, characterized in that The negative electrode material of the battery includes one or more of the following: carbon, silicon, tin, and germanium.

10. A charge and discharge management method, applied to an electronic device, wherein the electronic device includes a battery, the method comprising: At the third moment, setting the lower limit voltage of the battery to a fifth value; When the voltage of the battery reaches the fifth value, the battery stops discharging; At a fourth moment, the lower limit voltage of the battery is set to a sixth value; the fourth moment is after the third moment, and the sixth value is lower than the fifth value; when the voltage of the battery reaches the sixth value, the battery stops discharging.

11. An electronic device, characterized in that: The method comprises one or more processors and one or more memories; wherein the one or more memories are coupled to the one or more processors, and the one or more memories are used to store computer program code, wherein the computer program code comprises computer instructions, and when the one or more processors execute the computer instructions, the method according to any one of claims 1 to 9 or claim 10 is executed.

12. A chip system, applied to electronic equipment, characterized in that: The chip system includes one or more processors, and the processors are used to call computer instructions to execute the method according to any one of claims 1 to 9 or claim 10.

13. A computer-readable storage medium comprising instructions, characterized in that: When the instructions are executed on an electronic device, the method according to any one of claims 1 to 9 or claim 10 is executed.

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