Battery cycle life prediction method and device, storage medium and electronic equipment

Abstract

The application discloses a battery cycle life prediction method and device, a storage medium and an electronic device, which can perform a first battery cell cycle on a pre-lithiated battery and obtain a corresponding first discharge capacity, wherein the pre-lithiated battery has never been subjected to a battery cell cycle before the first battery cell cycle; the pre-lithiated battery is subjected to N times of the battery cell cycle, and a second discharge capacity corresponding to the Nth battery cell cycle is obtained, wherein the Nth battery cell cycle is counted from the first battery cell cycle; and the number of battery cycles of the pre-lithiated battery is determined according to the first discharge capacity and the second discharge capacity. It can be seen that the application can accurately predict the number of battery cycles of the pre-lithiated battery based on the discharge capacity of the pre-lithiated battery, and the prediction result is relatively accurate and the effect is relatively good.

Description

Technical Field

[0001] This invention relates to the field of energy storage, and in particular to a method, apparatus, storage medium, and electronic device for predicting battery cycle life. Background Technology

[0002] With the booming development of the automotive and energy storage industries, the requirements for the lifespan of lithium-ion power batteries and energy storage batteries are becoming increasingly stringent. Pre-lithiation of batteries is an effective method to improve the cycle life of lithium-ion batteries, but there is still no good method for predicting the cycle number of batteries after pre-lithiation. Therefore, how to accurately predict the cycle number of batteries after pre-lithiation has become a technical problem that urgently needs to be solved by researchers in this field. Summary of the Invention

[0003] In view of the above problems, the present invention provides a battery cycle life prediction method, apparatus, storage medium and electronic device that overcomes or at least partially solves the above problems.

[0004] Firstly, a method for predicting battery cycle life includes:

[0005] The pre-lithiated battery is subjected to its first cell cycle, and the corresponding first discharge capacity is obtained. Prior to the first cell cycle, the pre-lithiated battery has never undergone cell cycle.

[0006] The pre-lithiated battery is subjected to N cell cycles, and the second discharge capacity corresponding to the Nth cell cycle is obtained, wherein the Nth cell cycle is counted from the first cell cycle.

[0007] The number of battery cycles for the pre-lithiated battery is determined based on the first discharge capacity and the second discharge capacity.

[0008] Optionally, in some optional embodiments, the first cell cycle of the pre-lithiated battery to obtain the corresponding first discharge capacity includes:

[0009] The pre-lithiated battery is fully charged at a preset standard rate.

[0010] After the pre-lithiated battery is fully charged, it is discharged at the preset standard rate until the voltage of the pre-lithiated battery drops to the preset cutoff voltage.

[0011] When the voltage of the pre-lithiated battery drops to the preset cutoff voltage, the voltage of the pre-lithiated battery is maintained at the preset cutoff voltage, and the pre-lithiated battery is subjected to constant voltage discharge until the current of the pre-lithiated battery drops to the first preset cutoff current.

[0012] When the current of the pre-lithiated battery drops to the first preset cutoff current, the capacity discharged by the pre-lithiated battery during the constant voltage discharge is obtained as the first discharge capacity.

[0013] Optionally, in some optional embodiments, performing N cell cycles on the pre-lithiated battery and obtaining the second discharge capacity corresponding to the Nth cell cycle includes:

[0014] The pre-lithiated battery is subjected to N cell cycles, wherein each cell cycle comprises the following steps: fully charging the pre-lithiated battery at the preset standard rate; discharging the pre-lithiated battery at the preset standard rate after it is fully charged until its voltage drops to the preset cutoff voltage; maintaining the voltage of the pre-lithiated battery at the preset cutoff voltage while performing constant voltage discharge until its current drops to the first preset cutoff current;

[0015] After performing the Nth cell cycle on the pre-lithiated battery, the capacity discharged by the pre-lithiated battery during the constant voltage discharge of the Nth cell cycle is obtained as the second discharge capacity.

[0016] Optionally, in some optional embodiments, determining the number of battery cycles of the pre-lithiated battery based on the first discharge capacity and the second discharge capacity includes:

[0017] According to Formula 1: cycles=Q×η×N÷(C1-C2), the number of battery cycles of the pre-lithiated battery is calculated, where cycles is the number of battery cycles, Q is the preset pre-lithiation amount of the pre-lithiated battery, η is the pre-lithiation efficiency of the pre-lithiated battery, C1 is the first discharge capacity, and C2 is the second discharge capacity.

[0018] Optionally, in some alternative embodiments, before determining the number of battery cycles of the pre-lithiated battery based on the first discharge capacity and the second discharge capacity, the method further includes:

[0019] The battery without pre-lithiation is subjected to a first cell cycle to obtain a corresponding third discharge capacity. Prior to the first cell cycle, the battery without pre-lithiation has never undergone a cell cycle.

[0020] Optionally, in some optional embodiments, the first cell cycle of the un-lithiated battery to obtain the corresponding third discharge capacity includes:

[0021] The un-lithium-treated battery is fully charged at the preset standard rate.

[0022] After the un-lithiated battery is fully charged, it is discharged at the preset standard rate until the voltage of the un-lithiated battery drops to the preset cutoff voltage.

[0023] After the voltage of the un-lithiated battery drops to the preset cutoff voltage, the voltage of the un-lithiated battery is maintained at the preset cutoff voltage, and the un-lithiated battery is subjected to constant voltage discharge until the current of the un-lithiated battery drops to the first preset cutoff current.

[0024] When the current of the un-lithiated battery drops to the first preset cutoff current, the capacity discharged by the un-lithiated battery during the constant voltage discharge is obtained as the third discharge capacity.

[0025] Optionally, in some optional embodiments, determining the number of battery cycles of the pre-lithiated battery based on the first discharge capacity and the second discharge capacity includes:

[0026] According to Formula 2: cycles=(C1-C3)×N÷(C1-C2), the number of battery cycles of the pre-lithiated battery is calculated, where cycles is the number of battery cycles, C1 is the first discharge capacity, C2 is the second discharge capacity, and C3 is the third discharge capacity.

[0027] In a second aspect, a battery cycle life prediction device includes: a first capacity acquisition unit, a second capacity acquisition unit, and a cycle number determination unit;

[0028] The first capacity obtaining unit is used to perform the first cell cycle on the pre-lithiated battery and obtain the corresponding first discharge capacity, wherein the pre-lithiated battery has never been cell cycled before the first cell cycle is performed on the pre-lithiated battery.

[0029] The second capacity obtaining unit is used to perform N cell cycles on the pre-lithiated battery and obtain the second discharge capacity corresponding to the Nth cell cycle, wherein the Nth cell cycle is counted from the first cell cycle.

[0030] The cycle number determination unit is used to determine the number of battery cycles of the pre-lithiated battery based on the first discharge capacity and the second discharge capacity.

[0031] Thirdly, a computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the battery cycle life prediction method described in any of the preceding claims.

[0032] Fourthly, an electronic device includes at least one processor, and at least one memory and a bus connected to the processor; wherein the processor and the memory communicate with each other via the bus; the processor is configured to call program instructions in the memory to execute the battery cycle life prediction method described in any of the preceding claims.

[0033] By employing the above technical solution, the present invention provides a battery cycle life prediction method, apparatus, storage medium, and electronic device. This method allows for the first cell cycle of a pre-lithiated battery to be performed and the corresponding first discharge capacity to be obtained. Prior to this first cell cycle, the pre-lithiated battery has never undergone a cell cycle. The pre-lithiated battery is then subjected to N cell cycles, and a second discharge capacity corresponding to the Nth cell cycle is obtained. The Nth cell cycle is counted from the first cell cycle. Based on the first discharge capacity and the second discharge capacity, the number of battery cycles for the pre-lithiated battery is determined. Therefore, the present invention can accurately predict the number of battery cycles based on the discharge capacity of the pre-lithiated battery, with relatively accurate prediction results and good performance.

[0034] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0035] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0036] Figure 1 A flowchart of a battery cycle life prediction method provided by the present invention is shown;

[0037] Figure 2 A schematic diagram of a cell cycling process provided by the present invention is shown;

[0038] Figure 3 A schematic diagram of the structure of a battery cycle life prediction device provided by the present invention is shown;

[0039] Figure 4 A schematic diagram of the structure of an electronic device provided by the present invention is shown. Detailed Implementation

[0040] With the booming development of the automotive and energy storage industries, the requirements for the lifespan of lithium-ion power batteries and energy storage batteries are becoming increasingly stringent. Pre-lithiation is an effective method to improve the cycle life of lithium-ion batteries, but there is still no good method for predicting the number of cycles after pre-lithiation. Pre-lithiation refers to adding lithium to the inside of the lithium-ion battery to replenish lithium ions before it is put into operation. By replenishing lithium to the electrode materials through pre-lithiation, the irreversible lithium loss caused by the formation of the SEI film is offset, thereby improving the total capacity and energy density of the battery. During the first charge of the cell, an SEI film forms on the surface of the negative electrode, consuming active lithium. Pre-lithiation replenishes the consumed active lithium, thereby improving the specific capacity and cycle performance of the cell.

[0041] When designing battery cells, factors such as process tolerance and non-lithiation during charging are taken into account. Therefore, the CB value (capacity per unit area of ​​negative electrode or capacity per unit area of ​​positive electrode) of the battery cell is set to be greater than 1, usually around 1.1. Through pre-lithiation, the remaining uncharged negative electrode material can be intercalated with lithium, further increasing the active lithium storage of the negative electrode sheet.

[0042] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0043] like Figure 1 As shown, the present invention provides a battery cycle life prediction method, including: S100, S200 and S300;

[0044] S100. Perform the first cell cycle on the pre-lithiated battery and obtain the corresponding first discharge capacity.

[0045] Prior to the first cell cycle of the pre-lithiated battery, the pre-lithiated battery had never undergone cell cycle.

[0046] Optionally, the pre-lithiated battery mentioned in S100 can be understood as a battery that has completed pre-lithiation but has not yet been charged. Therefore, in S100, the present invention can perform the first cell cycle on the battery. It should be noted that: cell cycle refers to the complete process of charging and discharging the battery.

[0047] For example, in some optional implementations, S100 includes: steps 1.1, 1.2, 1.3, and 1.4;

[0048] Step 1.1: Fully charge the pre-lithiated battery at a preset standard rate;

[0049] Optionally, different battery cell products have different standard rates, which can be set according to the actual product. This invention does not impose any restrictions on this. It should be noted that the standard rate used in the charging and discharging processes is the same when the battery cells are cycled.

[0050] Optionally, fully charging the pre-lithiated battery means fully charging the pre-lithiated battery. That is, when charging the battery, the present invention can continuously monitor the battery's state of charge to ensure that the battery is fully charged. The present invention will not describe this in detail.

[0051] Step 1.2: After the pre-lithiated battery is fully charged, discharge the pre-lithiated battery at the preset standard rate until the voltage of the pre-lithiated battery drops to the preset cutoff voltage.

[0052] Optionally, different battery cell products have different cutoff voltages, which can be set according to the actual product. This invention does not impose any restrictions on this. It should be noted that during the battery discharge process, this invention can continuously monitor the battery voltage status. When the voltage drops to the preset cutoff voltage, the current discharge is stopped to facilitate switching to the discharge mode in step 1.3.

[0053] Step 1.3: When the voltage of the pre-lithiated battery drops to the preset cutoff voltage, maintain the voltage of the pre-lithiated battery at the preset cutoff voltage and perform constant voltage discharge on the pre-lithiated battery until the current of the pre-lithiated battery drops to the first preset cutoff current.

[0054] Optionally, when the voltage drops to a preset cutoff voltage, the present invention can switch to step 1.3. That is, the battery continues to discharge in a constant voltage manner, and the current state of the battery is continuously monitored until the current drops to a first preset cutoff current. The present invention does not limit this step.

[0055] Optionally, during constant voltage discharge, the battery voltage remains constant at a preset cutoff voltage. Through constant voltage discharge, the capacity of the cell polarization is released, and some of the pre-lithiated active lithium is stored in the remaining lithium vacancies in the positive electrode. The remaining active lithium is stored in the positive electrode in a lithium-rich state and as pseudocapacitively; this invention does not limit this process.

[0056] Optionally, the present invention does not impose specific limitations on the first preset cutoff current, and it can be set to a suitable value according to actual needs. For example, the first preset cutoff current mentioned in the present invention can be equal to 0.04C. Here, "C" refers to the nominal capacity, which is the capacity of the battery when it leaves the factory; for example: nominal capacity = 100Ah; cutoff current = 0.04C = 0.04 × 100 = 4A, and the present invention does not impose any limitations on this.

[0057] Step 1.4: When the current of the pre-lithiated battery drops to the first preset cutoff current, the capacity discharged by the pre-lithiated battery during the constant voltage discharge is obtained as the first discharge capacity.

[0058] Optionally, as described above, constant voltage discharge is initiated once the battery voltage drops to a preset cutoff voltage. This invention can collect the total discharge capacity of the battery during constant voltage discharge as a first discharge capacity; however, this invention does not limit this.

[0059] S200: Perform N cell cycles on the pre-lithiated battery and obtain the second discharge capacity corresponding to the Nth cell cycle.

[0060] The Nth cell cycle is counted starting from the first cell cycle;

[0061] Optionally, as mentioned above, each cell cycle can be roughly divided into three processes: full charging at a preset standard rate, discharging at a preset standard rate, and constant voltage discharging. To accurately predict the active lithium lost in each cell cycle, and thus predict how many cell cycles the pre-lithiated battery can undergo, this invention can collect the corresponding second discharge capacity after the battery has undergone N cell cycles. It should be noted that this invention does not impose a specific limitation on N, which can be set according to actual needs. Generally speaking, the smaller the value of N, the earlier the cell cycle life can be predicted while ensuring accuracy; the larger the value of N, the more it reduces the impact of cell testing errors and activation factors on battery life prediction. The range of N can be: 50 ≤ N ≤ 200.

[0062] For example, in some optional implementations, S200 includes: steps 2.1 and 2.2;

[0063] Step 2.1: Perform N cell cycles on the pre-lithiated battery, wherein each cell cycle includes the following steps: fully charging the pre-lithiated battery at the preset standard rate; discharging the pre-lithiated battery at the preset standard rate after it is fully charged until the voltage of the pre-lithiated battery drops to the preset cutoff voltage; maintaining the voltage of the pre-lithiated battery at the preset cutoff voltage while performing constant voltage discharge on the pre-lithiated battery until the current of the pre-lithiated battery drops to the first preset cutoff current;

[0064] Step 2.2: After performing the Nth cell cycle on the pre-lithiated battery, the capacity discharged by the pre-lithiated battery during the constant voltage discharge of the Nth cell cycle is obtained as the second discharge capacity.

[0065] Optionally, the N mentioned in this invention is counted starting from the first cell cycle. For example, if N equals 100, it means that 100 cell cycles are performed on the pre-lithiated battery, including the first cell cycle and the 99 cell cycles after the first cell cycle. This invention does not limit this.

[0066] S300. Determine the number of battery cycles for the pre-lithiated battery based on the first discharge capacity and the second discharge capacity.

[0067] Optionally, the battery cycle count mentioned in this invention can be understood as the theoretical battery cycle life. That is, how many times the battery can be charged and discharged; this invention does not limit this.

[0068] Optionally, the present invention does not impose specific limitations on the process of determining the number of battery cycles, and can set it according to actual needs.

[0069] For example, in some alternative implementations, S300 includes:

[0070] According to Formula 1: cycles=Q×η×N÷(C1-C2), the number of battery cycles of the pre-lithiated battery is calculated, where cycles is the number of battery cycles, Q is the preset pre-lithiation amount of the pre-lithiated battery, η is the pre-lithiation efficiency of the pre-lithiated battery, C1 is the first discharge capacity, and C2 is the second discharge capacity.

[0071] Optionally, the preset pre-lithiation amount of the pre-lithiated battery can be obtained directly after the battery is pre-lithiated, and the pre-lithiation efficiency is also a theoretical value that can be obtained. N has been explained in S200 above.

[0072] Optionally, in some alternative embodiments, before step S300, the method further includes: step 3.1;

[0073] Step 3.1: Perform the first cell cycle on the un-pre-lithiated battery and obtain the corresponding third discharge capacity. Before performing the first cell cycle on the un-pre-lithiated battery, the un-pre-lithiated battery has never been cell cycled.

[0074] Optionally, a non-pre-lithiated battery refers to a battery that has not yet undergone pre-lithiation, that is, a battery whose negative electrode material has not been lithium-intercalated. This invention does not limit this.

[0075] Optionally, the un-pre-lithiated battery in step 3.1 is also a battery that has not been charged. In order to determine the corresponding lithium loss of the un-pre-lithiated battery during the first cell cycle, the present invention can perform a first cell cycle on it.

[0076] For example, in some alternative implementations, step 3.1 includes: step 4.1, step 4.2, step 4.3, and step 4.4;

[0077] Step 4.1: Fully charge the un-pre-lithiated battery using the preset standard charging rate;

[0078] Optionally, for step 4.1, please refer to step 1.1 above for the same understanding, and the present invention will not repeat it.

[0079] Step 4.2: After the un-lithiated battery is fully charged, discharge the un-lithiated battery at the preset standard rate until the voltage of the un-lithiated battery drops to the preset cutoff voltage.

[0080] Optionally, for step 4.2, please refer to step 1.2 above for the same understanding, and this invention will not repeat it.

[0081] Step 4.3: After the voltage of the un-lithiated battery drops to the preset cutoff voltage, maintain the voltage of the un-lithiated battery at the preset cutoff voltage and perform constant voltage discharge on the un-lithiated battery until the current of the un-lithiated battery drops to the first preset cutoff current.

[0082] Optionally, for step 4.3, please refer to step 1.3 above for the same understanding, and this invention will not repeat it.

[0083] Step 4.4: When the current of the un-lithiated battery drops to the first preset cutoff current, the capacity discharged by the un-lithiated battery during the constant voltage discharge is obtained as the third discharge capacity.

[0084] Optionally, for step 4.4, please refer to step 1.4 above for the same understanding, and this invention will not repeat it.

[0085] Optionally, based on the embodiments including steps 4.1, omitting 4.2, 4.3, and 4.4, in some optional embodiments, S300 includes:

[0086] According to Formula 2: cycles=(C1-C3)×N÷(C1-C2), the number of battery cycles of the pre-lithiated battery is calculated, where cycles is the number of battery cycles, C1 is the first discharge capacity, C2 is the second discharge capacity, and C3 is the third discharge capacity.

[0087] It should be noted that the battery cycle count calculated based on Formula 1 or Formula 2 above can be understood as the predicted horizontal segment cycle life. The cell cycling process can be divided into horizontal and inclined segments; please refer to [link to relevant documentation] for details. Figure 2 To understand.

[0088] Optionally, to further clarify the present invention, specific examples are provided below to illustrate the solution and effects of the present invention.

[0089] The pre-lithiation method for lithium iron phosphate lithium-ion cells in this invention can be one or more of the following: positive electrode pre-lithiation, negative electrode pre-lithiation, electrochemical pre-lithiation, and chemical pre-lithiation.

[0090] As shown in Table 1, the specific parameters in Examples 1-8 are as follows:

[0091] The pre-lithiation method is lithium powder pre-lithiation;

[0092] The main cathode material is lithium iron phosphate (LPF), and the cathode formula is lithium iron phosphate:SP:PVDF = 97%:1%:2%;

[0093] The negative electrode material is graphite, and the formulation of the example is graphite: SP: CMC: SBR: 96.7%: 1%: 0.8%: 1.5%;

[0094] The cell's CB value is 1.12;

[0095] The electrolyte used is commercially available lithium iron phosphate electrolyte;

[0096] The diaphragm is made of PP and is 14 micrometers thick.

[0097] As shown in Table 1, the specific parameters in Examples 9-13 are as follows:

[0098] The pre-lithiation method is lithium powder pre-lithiation;

[0099] The positive electrode material uses NCM, with the following formula: NCM811:SP:CNTs:PVDF = 97.8%:0.8%:0.5%:0.9%.

[0100] The negative electrode material is a graphite and silicon oxide composite material with a ratio of graphite:silicon = 8:2; the electrode formulation is: main material: SP:CNTS:PAA:SBR = 95%:1.5%:0.1%:1.1%:2.2%;

[0101] The cell's CB value is 1.08;

[0102] The electrolyte used is a commercially available electrolyte suitable for high-nickel silicon-carbon materials;

[0103] The diaphragm is made of PE and has a thickness of 9 micrometers.

[0104] Testing method:

[0105] The cycling modes for both examples included: charging: 1C constant voltage charging to the upper limit voltage, cutoff current 0.05C; discharging: 1C constant current discharging to the lower limit voltage. The cycle life of different pre-lithiation capacities is compared in Table 1 below.

[0106] Table 1

[0107]

[0108] As shown in Table 1 above, different pre-lithiation levels will affect both the predicted and actual lifespan of the battery. This invention can determine the pre-lithiation levels for different cell products through continuous testing and experimentation, ensuring the accuracy of the prediction results. Furthermore, this invention can achieve rapid prediction results in a short period by reducing the number of cycles N, resulting in a faster response.

[0109] like Figure 3 As shown, the present invention provides a battery cycle life prediction device, including: a first capacity acquisition unit 100, a second capacity acquisition unit 200, and a cycle number determination unit 300;

[0110] The first capacity obtaining unit 100 is used to perform the first cell cycle on the pre-lithiated battery and obtain the corresponding first discharge capacity, wherein the pre-lithiated battery has never been cell cycled before the first cell cycle is performed on the pre-lithiated battery.

[0111] The second capacity obtaining unit 200 is used to perform N cell cycles on the pre-lithiated battery and obtain the second discharge capacity corresponding to the Nth cell cycle, wherein the Nth cell cycle is counted from the first cell cycle.

[0112] The cycle number determination unit 300 is used to determine the number of battery cycles of the pre-lithiated battery based on the first discharge capacity and the second discharge capacity.

[0113] Optionally, in some optional embodiments, the first capacity obtaining unit 100 includes: a first charging subunit, a first discharging unit, a first constant voltage subunit, and a first obtaining subunit;

[0114] The first charging subunit is used to fully charge the pre-lithiated battery at a preset standard rate;

[0115] The first discharge unit is used to discharge the pre-lithiated battery at the preset standard rate after the pre-lithiated battery is fully charged, until the voltage of the pre-lithiated battery drops to the preset cutoff voltage.

[0116] The first constant voltage subunit is used to maintain the voltage of the pre-lithiated battery at the preset cutoff voltage when the voltage of the pre-lithiated battery drops to the preset cutoff voltage, and to perform constant voltage discharge on the pre-lithiated battery until the current of the pre-lithiated battery drops to the first preset cutoff current.

[0117] The first obtaining subunit is used to obtain the capacity discharged by the pre-lithiated battery during the constant voltage discharge as the first discharge capacity when the current of the pre-lithiated battery drops to the first preset cutoff current.

[0118] Optionally, in some alternative embodiments, the second capacity obtaining unit 200 includes: a loop subunit and a second obtaining subunit;

[0119] The cycling subunit is used to perform N cell cycles on the pre-lithiated battery, wherein each cell cycle performs the following: fully charging the pre-lithiated battery at the preset standard rate; discharging the pre-lithiated battery at the preset standard rate after it is fully charged until the voltage of the pre-lithiated battery drops to the preset cutoff voltage; maintaining the voltage of the pre-lithiated battery at the preset cutoff voltage and performing constant voltage discharge on the pre-lithiated battery until the current of the pre-lithiated battery drops to the first preset cutoff current;

[0120] The second obtaining subunit is used to obtain, after performing the Nth cell cycle on the pre-lithiated battery, the capacity discharged by the pre-lithiated battery during the constant voltage discharge of the Nth cell cycle as the second discharge capacity.

[0121] Optionally, in some optional embodiments, the loop number determination unit 300 includes: a first number determination subunit;

[0122] The first cycle number determination subunit is used to calculate the number of battery cycles of the pre-lithiated battery according to formula 1: cycles=Q×η×N÷(C1-C2), where cycles is the number of battery cycles, Q is the preset pre-lithiated amount of the pre-lithiated battery, η is the pre-lithiated efficiency of the pre-lithiated battery, C1 is the first discharge capacity, and C2 is the second discharge capacity.

[0123] Optionally, in some alternative embodiments, the apparatus further includes: a third capacity acquisition unit;

[0124] The third capacity obtaining unit is used to perform a first cell cycle on the un-lithiated battery before determining the number of battery cycles of the pre-lithiated battery based on the first discharge capacity and the second discharge capacity, and to obtain the corresponding third discharge capacity, wherein the un-lithiated battery has never been cell cycled before performing the first cell cycle on the un-lithiated battery.

[0125] Optionally, in some alternative embodiments, the third capacity acquisition unit includes: a second charging subunit, a second discharging subunit, a second constant voltage subunit, and a third acquisition subunit;

[0126] The second charging subunit is used to fully charge the un-lithium-charged battery at the preset standard rate;

[0127] The second discharge unit is used to discharge the un-lithiated battery at the preset standard rate after the un-lithiated battery is fully charged, until the voltage of the un-lithiated battery drops to the preset cutoff voltage.

[0128] The second constant voltage subunit is used to maintain the voltage of the un-lithiated battery at the preset cutoff voltage after the voltage of the un-lithiated battery drops to the preset cutoff voltage, and to perform constant voltage discharge on the un-lithiated battery until the current of the un-lithiated battery drops to the first preset cutoff current.

[0129] The third obtaining subunit is used to obtain the capacity discharged by the un-lithiated battery during the constant voltage discharge as the third discharge capacity when the current of the un-lithiated battery drops to the first preset cutoff current.

[0130] Optionally, in some alternative embodiments, the loop number determination unit 300 includes: a second number determination subunit;

[0131] The second cycle determination subunit is used to calculate the number of battery cycles of the pre-lithiated battery according to formula 2: cycles=(C1-C3)×N÷(C1-C2), where cycles is the number of battery cycles, C1 is the first discharge capacity, C2 is the second discharge capacity, and C3 is the third discharge capacity.

[0132] The present invention provides a computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the battery cycle life prediction method described in any of the preceding claims.

[0133] like Figure 4 As shown, the present invention provides an electronic device 70, which includes at least one processor 701, at least one memory 702 and a bus 703 connected to the processor 701; wherein the processor 701 and the memory 702 communicate with each other through the bus 703; the processor 701 is used to call program instructions in the memory 702 to execute the battery cycle life prediction method described above.

[0134] In this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, without necessarily requiring or implying any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0135] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0136] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined in this invention may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0137] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A method for predicting battery cycle life, characterized in that, include: The pre-lithiated battery is subjected to its first cell cycle, and the corresponding first discharge capacity is obtained. Prior to the first cell cycle, the pre-lithiated battery has never undergone cell cycle. The pre-lithiated battery is subjected to N cell cycles, and the second discharge capacity corresponding to the Nth cell cycle is obtained, wherein the Nth cell cycle is counted from the first cell cycle. The number of battery cycles of the pre-lithiated battery is determined based on the first discharge capacity and the second discharge capacity, including: according to Formula 1: The number of battery cycles of the pre-lithiated battery is calculated, wherein the... The number of battery cycles, the The preset pre-lithiation amount of the pre-lithiated battery, the The pre-lithiation efficiency of the pre-lithiated battery is... For the first discharge capacity, the This is the second discharge capacity.

2. The method according to claim 1, characterized in that, The process of performing the first cell cycle on the pre-lithiated battery and obtaining the corresponding first discharge capacity includes: The pre-lithiated battery is fully charged at a preset standard rate. After the pre-lithiated battery is fully charged, it is discharged at the preset standard rate until the voltage of the pre-lithiated battery drops to the preset cutoff voltage. When the voltage of the pre-lithiated battery drops to the preset cutoff voltage, the voltage of the pre-lithiated battery is maintained at the preset cutoff voltage, and the pre-lithiated battery is subjected to constant voltage discharge until the current of the pre-lithiated battery drops to the first preset cutoff current. When the current of the pre-lithiated battery drops to the first preset cutoff current, the capacity discharged by the pre-lithiated battery during the constant voltage discharge is obtained as the first discharge capacity.

3. The method according to claim 2, characterized in that, The step of performing N cell cycles on the pre-lithiated battery and obtaining the second discharge capacity corresponding to the Nth cell cycle includes: The pre-lithiated battery is subjected to N cell cycles, wherein each cell cycle comprises the following steps: fully charging the pre-lithiated battery at the preset standard rate; discharging the pre-lithiated battery at the preset standard rate after it is fully charged until its voltage drops to the preset cutoff voltage; maintaining the voltage of the pre-lithiated battery at the preset cutoff voltage while performing constant voltage discharge until its current drops to the first preset cutoff current; After performing the Nth cell cycle on the pre-lithiated battery, the capacity discharged by the pre-lithiated battery during the constant voltage discharge of the Nth cell cycle is obtained as the second discharge capacity.

4. The method according to claim 3, characterized in that, Before determining the number of battery cycles of the pre-lithiated battery based on the first discharge capacity and the second discharge capacity, the method further includes: The battery without pre-lithiation is subjected to a first cell cycle to obtain a corresponding third discharge capacity. Prior to the first cell cycle, the battery without pre-lithiation has never undergone a cell cycle.

5. The method according to claim 4, characterized in that, The process of performing the first cell cycle on the un-lithiated battery and obtaining the corresponding third discharge capacity includes: The un-lithium-treated battery is fully charged at the preset standard rate. After the un-lithiated battery is fully charged, it is discharged at the preset standard rate until the voltage of the un-lithiated battery drops to the preset cutoff voltage. After the voltage of the un-lithiated battery drops to the preset cutoff voltage, the voltage of the un-lithiated battery is maintained at the preset cutoff voltage, and the un-lithiated battery is subjected to constant voltage discharge until the current of the un-lithiated battery drops to the first preset cutoff current. When the current of the un-lithiated battery drops to the first preset cutoff current, the capacity discharged by the un-lithiated battery during the constant voltage discharge is obtained as the third discharge capacity.

6. The method according to claim 5, characterized in that, Determining the number of battery cycles for the pre-lithiated battery based on the first discharge capacity and the second discharge capacity includes: According to formula 2: The number of battery cycles of the pre-lithiated battery is calculated, where is the number of battery cycles, and is... For the first discharge capacity, the The second discharge capacity, the This refers to the third discharge capacity.

7. A battery cycle life prediction device, characterized in that, include: The unit comprises a first capacity acquisition unit, a second capacity acquisition unit, and a cycle number determination unit. The first capacity obtaining unit is used to perform the first cell cycle on the pre-lithiated battery and obtain the corresponding first discharge capacity, wherein the pre-lithiated battery has never been cell cycled before the first cell cycle is performed on the pre-lithiated battery. The second capacity obtaining unit is used to perform N cell cycles on the pre-lithiated battery and obtain the second discharge capacity corresponding to the Nth cell cycle, wherein the Nth cell cycle is counted from the first cell cycle. The cycle number determination unit is used to determine the battery cycle number of the pre-lithiated battery based on the first discharge capacity and the second discharge capacity, including: according to Formula 1: The number of battery cycles of the pre-lithiated battery is calculated, wherein the... The number of battery cycles, the The preset pre-lithiation amount of the pre-lithiated battery, the The pre-lithiation efficiency of the pre-lithiated battery is... For the first discharge capacity, the This is the second discharge capacity.

8. A computer-readable storage medium having a program stored thereon, characterized in that, When the program is executed by the processor, it implements the battery cycle life prediction method as described in any one of claims 1 to 6.

9. An electronic device, characterized in that, The electronic device includes at least one processor, and at least one memory and a bus connected to the processor; wherein the processor and the memory communicate with each other through the bus; the processor is used to call program instructions in the memory to execute the battery cycle life prediction method as described in any one of claims 1 to 6.

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