Battery health state assessment method and device, computer equipment and storage medium

Abstract

The invention relates to the technical field of battery state evaluation, and discloses a battery health state evaluation method and device, computer equipment and a storage medium, and the method comprises the steps: obtaining single battery thermal parameters and battery system thermal parameters under different battery cycle numbers and set temperatures; calculating battery heat production based on the single battery thermal parameters, and obtaining a reference state function relationship based on a first single battery specific heat capacity change rate of the battery heat production and a first battery capacity change rate under different battery circulation turns; calculating the calorific value of all single batteries in the battery system based on the thermal parameters of the battery system, calculating the specific heat capacity change rate of a second single battery and the capacity change rate of the second battery based on the calorific value, and fitting to obtain a system function relationship; and evaluating the health state of the battery system based on the reference state function relationship and the system function relationship. The method can accurately evaluate the health state of the battery system, improves the evaluation precision and efficiency, and solves a problem that it is difficult to accurately evaluate the health state of the battery.

Description

Technical Field

[0001] The present invention relates to the technical field of battery status assessment, and in particular to a battery health status assessment method, device, computer equipment and storage medium. Background Art

[0002] Lithium-ion batteries, sodium-ion batteries, etc. are widely used in power batteries, energy storage batteries, and 3C consumer fields (computers, communications, and consumer electronics). Long-term use of batteries will be accompanied by aging, resulting in reduced storage capacity and rate performance, and may also pose safety hazards under extreme conditions. Currently, the commonly used SOH (State of Health) algorithms include the capacity method and the internal resistance method, but due to the limitations of actual usage, it is difficult to obtain a complete charging and discharging process; and the ohmic internal resistance is affected by state parameters such as discharge depth, temperature, SOC (State of Charge), and aging status, and there will be deviations in practice, making it difficult to accurately evaluate the battery health status. Summary of the invention

[0003] In view of this, the present invention provides a battery health status assessment method, apparatus, computer equipment and storage medium to solve the problem of difficulty in accurately assessing the battery health status.

[0004] In a first aspect, the present invention provides a method for evaluating a battery health status, the method comprising:

[0005] Obtain thermal parameters of single cells and battery systems at different battery cycle times and set temperatures;

[0006] Calculating the heat generation of the battery based on the thermal parameters of the single battery, and calculating the change rate of the specific heat capacity of the first single battery and the change rate of the first battery capacity under different battery cycle numbers based on the heat generation of the battery, and fitting the change rate of the specific heat capacity of the first single battery and the change rate of the first battery capacity to obtain a reference state function relationship;

[0007] Calculate the heat generated by all the single cells in the battery system based on the thermal parameters of the battery system, calculate the specific heat capacity change rate of the second single cell and the capacity change rate of the second battery based on the heat generated by all the single cells, and fit the specific heat capacity change rate of the second single cell and the capacity change rate of the second battery to obtain a system function relationship;

[0008] The displayed battery system health state is evaluated based on the reference state function relationship and the system function relationship, and the displayed unqualified battery system health state is corrected.

[0009] The battery health status assessment method provided by the present invention calculates the battery specific heat capacity change rate and the battery capacity change rate based on the changes in battery temperature and heat generation, and compares the calculated battery specific heat capacity change rate and battery capacity change rate with pre-collected specific heat capacity change rate data of the battery in a less aged state, so as to compare whether the SOH (State of Health) estimated by the current battery system has a large deviation, and judges the health status of the battery system based on the deviation. The health status of the battery system can be accurately assessed, the assessment accuracy and efficiency can be improved, the safety performance of the battery system is improved, and the problem of difficulty in accurately assessing the battery health status is solved.

[0010] In an optional embodiment, the thermal parameters of the single cell battery include the single cell specific heat capacity and the single cell temperature variation;

[0011] Calculation of battery heat generation based on thermal parameters of single battery includes:

[0012] The heat generated by the battery is calculated based on the specific heat capacity of the single battery and the temperature change of the single cell.

[0013] The battery health status assessment method provided by the present invention can accurately calculate the heat generation of the battery based on the specific heat capacity of the single cell battery and the temperature change of the single cell battery, providing conditions for subsequent fitting to obtain the reference state function relationship.

[0014] In an optional embodiment, the thermal parameters of the single cell battery further include the internal resistance of the single cell battery;

[0015] Based on the heat generation of the battery, the specific heat capacity change rate of the first single battery and the capacity change rate of the first battery are calculated, and the reference state function relationship is obtained by fitting the specific heat capacity change rate of the first single battery and the capacity change rate of the first battery under different battery cycle numbers:

[0016] Differentiate the heat generated by the battery to obtain a change rate of the specific heat capacity of the first single battery;

[0017] Obtaining the discharge capacity of a single battery and the initial capacity of a single battery under different battery cycle numbers, and calculating the first battery capacity change rate using a preset battery health status parameter model based on the discharge capacity of the single battery and the initial capacity of the single battery;

[0018] The first single cell specific heat capacity change rate and the first battery capacity change rate are fitted to obtain a functional relationship between the first specific heat capacity change rate and the battery health state. Meanwhile, the single cell internal resistance and the first battery capacity change rate are fitted to obtain a functional relationship between the first single cell internal resistance and the battery health. The functional relationship between the first specific heat capacity change rate and the battery health state and the functional relationship between the first single cell internal resistance and the battery health state are used as reference state functional relationships.

[0019] The battery health status assessment method provided by the present invention performs differential calculation on the heat generated by the battery to obtain the change in specific heat capacity of the first single cell battery; obtains the discharge capacity of the single cell battery and the initial capacity of the single cell battery under different battery cycle numbers, and calculates the first battery capacity change rate based on the discharge capacity of the single cell battery and the initial capacity of the single cell battery using a preset battery health status parameter model; fits the first single cell battery specific heat capacity change rate and the first battery capacity change rate to obtain a functional relationship between the first specific heat capacity change rate and the battery health status, and simultaneously fits the single cell battery internal resistance and the first battery capacity change rate to obtain a functional relationship between the first single cell battery internal resistance and the battery health, thereby achieving the purpose of obtaining a reference state functional relationship and providing reference data for battery health status assessment.

[0020] In an optional embodiment, the battery system thermal parameter includes the battery system heat generation;

[0021] The calculation of the heat generated by all cells in the battery system based on the thermal parameters of the battery system includes:

[0022] Obtaining multiple other components in the battery system in addition to all cells;

[0023] Calculate the heat generated by multiple other components;

[0024] The heat generated by all cells in the battery system is calculated based on the heat generated by the battery system, the heat generated by multiple other components, and the number of cells.

[0025] The battery health status assessment method provided by the present invention obtains the calorific value of all single cells in the battery system by calculating the calorific value of the battery system, the calorific value of multiple other components and the number of single cells in all cells. It has the advantages of simple calculation and high efficiency, and provides conditions for subsequent assessment of the health status of the battery system.

[0026] In an optional implementation, the specific heat capacity change rate of the second single battery and the second battery capacity change rate are calculated based on the heat generated by all single batteries, and the system function relationship is obtained by fitting the specific heat capacity change rate of the second single battery and the second battery capacity change rate, including:

[0027] Calculate the change rate of specific heat capacity of the second single cell based on the heat generated by all single cells;

[0028] Obtaining a second battery capacity change rate and a second single battery internal resistance calculated using a preset battery health status parameter model in the current state of the battery system;

[0029] The second single cell specific heat capacity change rate and the second battery capacity change rate are fitted to obtain a functional relationship between the second specific heat capacity change rate and the battery health state. At the same time, the second single cell internal resistance and the second battery capacity change rate are fitted to obtain a functional relationship between the second single cell internal resistance and the battery health. The functional relationship between the second specific heat capacity change rate and the battery health state and the functional relationship between the second single cell internal resistance and the battery health are used as the system functional relationship.

[0030] The battery health status assessment method provided by the present invention calculates the specific heat capacity change rate of the second single battery based on the heat generated by all single batteries; obtains the second battery capacity change rate and the second single battery internal resistance calculated by using a preset battery health status parameter model under the current state of the battery system; fits the second single battery specific heat capacity change rate and the second battery capacity change rate to obtain a functional relationship between the second specific heat capacity change rate and the battery health status, and simultaneously fits the second single battery internal resistance and the second battery capacity change rate to obtain a functional relationship between the second single battery internal resistance and the battery health, thereby achieving the purpose of obtaining a system functional relationship and providing comparative data for battery health status assessment.

[0031] In an optional implementation, evaluating the displayed battery system health status based on the reference state function relationship and the system function relationship includes:

[0032] Calculating a first difference between a functional relationship between a first specific heat capacity change rate and a battery health state and a second functional relationship between a specific heat capacity change rate and a battery health state, and calculating a second difference between a functional relationship between a first single cell internal resistance and a battery health state and a second single cell internal resistance and a battery health state;

[0033] It is determined whether the first difference and the second difference are within a preset error tolerance range. If so, the displayed battery system health status is deemed to have a qualified accuracy; otherwise, the displayed battery system health status is deemed to have an unqualified accuracy.

[0034] The battery health status assessment method provided by the present invention calculates a first difference between a functional relationship between a first specific heat capacity change rate and a battery health status and a functional relationship between a second specific heat capacity change rate and a battery health status, and calculates a second difference between a functional relationship between a first single cell internal resistance and a battery health status and a functional relationship between a second single cell internal resistance and a battery health status; determines whether the first difference and the second difference are within a preset error allowable range, and if so, it is deemed that the displayed battery system health status has qualified accuracy; otherwise, it is deemed that the displayed battery system health status has unqualified accuracy, and the battery system health status is accurately judged by two determination conditions, thereby improving the assessment accuracy and enhancing the safety performance of the battery system.

[0035] In an optional implementation, correcting the displayed unqualified battery system health status includes: when the displayed battery system health status accuracy is unqualified, using a preset correction coefficient or compensation method to correct a preset battery health status parameter model.

[0036] The battery health status assessment method provided by the present invention adopts a preset correction coefficient or compensation method to correct the preset battery health status parameter model when the accuracy of the displayed battery system health status is unqualified, thereby further improving the accuracy of the preset battery health status parameter model and thus improving the accuracy of the battery health status assessment.

[0037] In a second aspect, the present invention provides a battery health status assessment device, the device comprising:

[0038] A parameter acquisition module is used to obtain thermal parameters of single cells and battery systems at different battery cycle numbers and set temperatures;

[0039] A reference state function calculation module is used to calculate the heat generation of the battery based on the thermal parameters of the single battery, and calculate the change rate of the specific heat capacity of the first single battery and the change rate of the first battery capacity under different battery cycle numbers based on the heat generation of the battery, and fit the change rate of the specific heat capacity of the first single battery and the change rate of the first battery capacity to obtain a reference state function relationship;

[0040] A system function calculation module, used to calculate the heat generated by all the single cells in the battery system based on the thermal parameters of the battery system, and calculate the specific heat capacity change rate of the second single cell and the second battery capacity change rate based on the heat generated by all the single cells, and fit the specific heat capacity change rate of the second single cell and the second battery capacity change rate to obtain a system function relationship;

[0041] The state evaluation module is used to evaluate the displayed battery system health state based on the reference state function relationship and the system function relationship, and to correct the displayed unqualified battery system health state.

[0042] In a third aspect, the present invention provides a computer device, comprising: a memory and a processor, the memory and the processor are communicatively connected to each other, computer instructions are stored in the memory, and the processor executes the battery health status assessment method of the first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0043] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the battery health status assessment method of the first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 is a flowchart of a battery health status assessment method according to an embodiment of the present invention;

[0046] Figure 2 is a flow chart of another battery health status assessment method according to an embodiment of the present invention;

[0047] Figure 3 is a flowchart of another battery health status assessment method according to an embodiment of the present invention;

[0048] Figure 4 is a schematic diagram of the f(dc, SOH) function relationship according to an embodiment of the present invention;

[0049] Figure 5 is a schematic diagram of the functional relationship of f(R, SOH) according to an embodiment of the present invention;

[0050] Figure 6 is a schematic diagram of the F(dc′, SOH′) function relationship according to an embodiment of the present invention;

[0051] Figure 7 is a schematic diagram of the F(R′, SOH′) function relationship according to an embodiment of the present invention;

[0052] Figure 8 is a schematic diagram comparing the functional relationship between f(dc, SOH) and F(dc′, SOH′) according to an embodiment of the present invention;

[0053] Fig. 9 is a schematic diagram comparing the functional relationship between f(R, SOH) and F(R′, SOH′) according to an embodiment of the present invention;

[0054] Fig.10 is a structural block diagram of a battery health status assessment device according to an embodiment of the present invention;

[0055] Fig.11 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0057] According to an embodiment of the present invention, an embodiment of a battery health status assessment method is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0058] In this embodiment, a battery health status assessment method is provided, which can be used in mobile terminals, such as tablet computers, central processing units, servers, etc. Figure 1 is a flow chart of a battery health status assessment method according to an embodiment of the present invention. Figure 1 As shown, the process includes the following steps:

[0059] Step S101, obtaining thermal parameters of single cells and battery system at different battery cycle numbers and set temperatures.

[0060] Specifically, the number of battery cycles refers to the number of cycles that the battery can maintain the rated capacity after completing a charge and discharge cycle, for example, it can be 1 cycle, 100 cycles, 200 cycles, 300 cycles, ..., and the number of battery cycles is determined according to the actual situation. The set temperature refers to the temperature of the single cell, which is set to T, for example, T = 25°C. The thermal parameters of the single cell include the heat generation Q1, Q2, Q3... under different battery cycle numbers, the specific heat capacity of the single cell c1, c2, c3..., the temperature change ΔT1, ΔT2, ΔT3...; and the DCR impedance (Direct Current Resistance) R1, R2, R3... under different cycles. DCR impedance is also called the internal resistance of the single cell. The thermal parameters of the battery system include the heat generation and temperature change of the battery system at the set temperature.

[0061] Step S102, calculating the heat generation of the battery based on the thermal parameters of the single battery, and calculating the change rate of the specific heat capacity of the first single battery and the change rate of the first battery capacity under different battery cycle numbers based on the heat generation of the battery, and fitting the change rate of the specific heat capacity of the first single battery and the change rate of the first battery capacity to obtain a reference state function relationship.

[0062] Specifically, the heat generation of the battery can be obtained based on the specific heat capacity and temperature change in the single cell parameters. For example, differential calculation can be used to obtain the specific heat capacity change rate of the first single cell and the first battery capacity change rate under different battery cycle numbers based on the battery heat generation, and the specific heat capacity change rate of the first single cell and the first battery capacity change rate are fitted to obtain a reference state function relationship.

[0063] Step S103, calculating the heat generated by all the single cells in the battery system based on the thermal parameters of the battery system, and calculating the specific heat capacity change rate of the second single cell and the second battery capacity change rate based on the heat generated by all the single cells, and fitting the specific heat capacity change rate of the second single cell and the second battery capacity change rate to obtain a system function relationship.

[0064] Specifically, the battery system is composed of components consisting of all single cells and other box components.

[0065] The heating value of other box components is calculated based on the thermal parameters of the battery system, and the heating value of all single cells is obtained based on the total heating value of the battery system and the heating value of other box components. The heating value of all single cells in the battery system can be obtained. For example, the second single cell specific heat capacity change rate and the second battery capacity change rate can be calculated based on the heating value of all single cells by differential calculation, and the second single cell specific heat capacity change rate and the second battery capacity change rate can be fitted to obtain the system function relationship.

[0066] Step S104 , evaluating the displayed battery system health state based on the reference state function relationship and the system function relationship, and correcting the displayed unqualified battery system health state.

[0067] Specifically, the corresponding specific heat capacity change rate and battery capacity change rate in the reference state function relationship and the system function relationship are compared to evaluate the battery system health state and correct the displayed unqualified battery system health state.

[0068] The battery health status assessment method provided in this embodiment calculates the battery specific heat capacity change rate and the battery capacity change rate based on the changes in battery temperature and heat generation, and compares the calculated battery specific heat capacity change rate and battery capacity change rate with the pre-collected specific heat capacity change rate data of the battery in a less aged state, so as to compare whether the SOH (State of Health) estimated by the current battery system has a large deviation, and judge the health status of the battery system based on the deviation. It can accurately assess the health status of the battery system, improve the assessment accuracy and assessment efficiency, improve the safety performance of the battery system, solve the problem of difficulty in accurately assessing the battery health status, correct the displayed unqualified battery system health status, and further improve the accuracy of battery health status assessment.

[0069] In this embodiment, a battery health status assessment method is provided, which can be used in mobile terminals, such as tablet computers, central processing units, servers, etc. Figure 2 is a flow chart of a battery health status assessment method according to an embodiment of the present invention. Figure 2 As shown, the process includes the following steps:

[0070] Step S201, obtain the thermal parameters of the single battery and the battery system at different battery cycle times and set temperatures. Figure 1 Step S101 of the illustrated embodiment will not be described in detail here.

[0071] Step S202, the heat generation of the battery is calculated based on the thermal parameters of the single battery, and the specific heat capacity change rate of the first single battery and the first battery capacity change rate under different battery cycle numbers are calculated based on the battery heat generation, and the specific heat capacity change rate of the first single battery and the first battery capacity change rate are fitted to obtain a reference state function relationship.

[0072] Specifically, the thermal parameters of the single cell battery include the specific heat capacity of the single cell battery, the temperature change of the single cell battery, and the internal resistance of the single cell battery. The above step S202 includes:

[0073] Step S2021, calculating the heat generation of the battery based on the specific heat capacity of the single battery and the temperature change of the single cell.

[0074] Specifically, the formula for calculating the heat generation of the battery based on the specific heat capacity of the single battery and the temperature change of the single cell is as follows:

[0075] Q=c m ΔT(1);

[0076] Where Q is the heat generated, c m is the specific heat capacity of the single cell, ΔT is the temperature change, and m is the number of battery cycles.

[0077] Step S2022: Differentiate the heat generated by the battery to obtain a change rate of specific heat capacity of the first single battery.

[0078] Specifically, the calculation formula of the change rate of specific heat capacity of the first single cell is as follows:

[0079] dc=1 / m*(dQ / dT)(2);

[0080] Where: dc is the change rate of the specific heat capacity of the first single battery, and dQ / dT is the specific heat capacity under all battery cycle numbers.

[0081] Step S2023, obtaining the discharge capacity of the single battery and the initial capacity of the single battery under different battery cycle numbers, and calculating the first battery capacity change rate based on the discharge capacity of the single battery and the initial capacity of the single battery using a preset battery health status parameter model.

[0082] Specifically, the preset battery health status parameter model is a SOH parameter model set according to actual conditions, so that the computer can calculate the first battery capacity change rate of the single cell based on the single cell discharge capacity and the single cell initial capacity through the SOH parameter model and display the battery health status.

[0083] The calculation formula for calculating the first battery capacity change rate based on the single battery discharge capacity and the single battery initial capacity using the preset battery health status parameter model is as follows:

[0084] SOH = C / C0 (3);

[0085] Among them, SOH is the first battery capacity change rate that characterizes the battery health state, C is the single cell discharge capacity under all battery cycle numbers, and C0 is the single cell initial capacity.

[0086] Step S2024, fitting the first single cell specific heat capacity change rate and the first battery capacity change rate to obtain a functional relationship between the first specific heat capacity change rate and the battery health state, and fitting the single cell internal resistance and the first battery capacity change rate to obtain a functional relationship between the first single cell internal resistance and the battery health state, and taking the functional relationship between the first specific heat capacity change rate and the battery health state and the functional relationship between the first single cell internal resistance and the battery health state as the reference state functional relationship.

[0087] Specifically, the first single cell specific heat capacity change rate dc and the first battery capacity change rate SOH are fitted by computer data fitting to obtain a functional relationship between the first specific heat capacity change rate and the battery health state f(dc, SOH) or f′(dQ / dT, SOH).

[0088] In the actual battery charging and discharging process, the first single cell specific heat capacity change rate and the first battery capacity change rate data calculated in real time are used to fit the single cell internal resistance R and the first battery capacity change rate SOH through computer data fitting to obtain the functional relationship f(R, SOH) between the first single cell internal resistance and the battery health state. For the specific fitting process, please refer to the relevant technical content and will not be repeated here. The f(dc, SOH) functional relationship diagram and the f(R, SOH) functional relationship diagram are shown as follows: Figure 4 and Figure 5 shown.

[0089] Step S203, calculating the heat generated by all the single cells in the battery system based on the thermal parameters of the battery system, and calculating the specific heat capacity change rate of the second single cell and the second battery capacity change rate based on the heat generated by all the single cells, and fitting the specific heat capacity change rate of the second single cell and the second battery capacity change rate to obtain a system function relationship.

[0090] Specifically, the thermal parameters of the battery system include the heat generation and temperature data of the battery system, and the heat generation q of the battery system at different temperatures is recorded. The heat generation during the charging and discharging process of the battery system can be obtained by a heat flow meter or other means, and the temperature data is collected by a temperature sensor. According to the temperature data of other components of the battery system except all cells, the temperature change rate of the battery system is obtained as Δt. The above step S203 includes:

[0091] Step S2031, obtaining multiple components other than all cells in the battery system; calculating the heat generated by multiple other components; and calculating the heat generated by all single cells in the battery system based on the heat generated by the battery system, the heat generated by multiple other components and the number of single cells in all cells.

[0092] Specifically, the heat generation calculation formulas of multiple other components are as follows:

[0093] q t =∑c i m i Δt i (4);

[0094] Among them, q t is the heat generated by multiple other components, i is the i-th other component of the battery system, c i is the specific heat capacity of the i-th other component, m i is the mass of the i-th other component, Δt i is the temperature rise of the i-th other component.

[0095] The calculation formula for calculating the heat generated by all cells in the battery system based on the heat generated by the battery system, the heat generated by multiple other components, and the total number of cells in the battery system is as follows:

[0096] Q′=(qq t ) / x(5);

[0097] Among them, Q' is the heat generated by all single cells in the battery system, and x is the number of single cells.

[0098] Step S2032: Calculate the change rate of specific heat capacity of the second single battery based on the heat generated by all single batteries.

[0099] Specifically, the temperature change of the single battery in the battery system is ΔT′, and the specific heat capacity of the second single battery is calculated to be c′=dQ′ / dT′. The second specific heat capacity change rate is obtained according to Q′, ΔT′ and c′ collected under multiple states, and the calculation formula is as follows:

[0100] dc′=1 / m*(dQ′ / dT′)(6);

[0101] Wherein, dc′ is the second specific heat capacity change rate, and dQ′ / dT′ is the second single cell specific heat capacity.

[0102] Step S2033, obtaining a second battery capacity change rate and a second single battery internal resistance calculated by using a preset battery health status parameter model in the current state of the battery system.

[0103] Specifically, in a battery system including multiple single cells, in order to save time and improve calculation efficiency, a preset battery health status parameter model is used to batch calculate the specific heat capacity change rate SOH′ of the second single cell, thereby achieving the effect of fast and accurate calculation.

[0104] The SOH′ calculated and displayed by using the preset battery health status parameter model under different temperature conditions of the current battery system is the second battery capacity change rate SOH′. 2 Q′x′ (x′ is time, I is current), calculate the internal resistance R′ of the second single battery, or calculate and obtain the internal resistance R′ of the second single battery under the pulse condition of the battery system.

[0105] Step S2034, fitting the second single cell specific heat capacity change rate and the second battery capacity change rate to obtain a functional relationship between the second specific heat capacity change rate and the battery health state, and fitting the second single cell internal resistance and the second battery capacity change rate to obtain a functional relationship between the second single cell internal resistance and the battery health, and taking the functional relationship between the second specific heat capacity change rate and the battery health state and the functional relationship between the second single cell internal resistance and the battery health as the system functional relationship.

[0106] Specifically, during the actual battery charge and discharge process, the functional relationship between the second battery capacity change rate SOH′ and the second single cell specific heat capacity change rate dc′ or dQ′ / dT′ is fitted using computer data to obtain the functional relationship between the second specific heat capacity change rate dc′ or dQ′ / dT′ and the battery health state F(dc′, SOH′) or F′(dQ′ / dT′, SOH′).

[0107] By fitting the second single cell internal resistance R' and the second battery capacity change rate SOH' through computer data, the functional relationship F(R', SOH') between the second single cell internal resistance R' and the battery health state is obtained. For the specific fitting process, please refer to the relevant technical content and will not be repeated here.

[0108] The diagrams of the functional relationship of F(dc′, SOH′) and F(R′, SOH′) are shown in the figure below. Figure 6 and Figure 7 shown.

[0109] Step S204: Evaluate the health status of the battery system based on the reference state function relationship and the system function relationship. Figure 1 Step S104 of the illustrated embodiment will not be described in detail here.

[0110] The battery health status assessment method provided in this embodiment obtains the reference state function relationship and the system function relationship through the thermal parameters of the single cell battery and the thermal parameters of the battery system respectively, has the advantages of simple calculation and high efficiency, and provides conditions for the subsequent assessment of the battery system health status.

[0111] In this embodiment, a battery health status assessment method is provided, which can be used in mobile terminals, such as tablet computers, central processing units, servers, etc. Figure 3 is a flow chart of a battery health status assessment method according to an embodiment of the present invention. Figure 3 As shown, the process includes the following steps:

[0112] Step S301, obtain the thermal parameters of the single battery and the battery system at different battery cycle times and set temperatures. Figure 2 Step S201 of the illustrated embodiment will not be described in detail here.

[0113] Step S302, calculating the heat generation of the battery based on the thermal parameters of the single battery, and calculating the change rate of the specific heat capacity of the first single battery and the change rate of the first battery capacity under different battery cycle numbers based on the heat generation of the battery, and fitting the change rate of the specific heat capacity of the first single battery and the change rate of the first battery capacity to obtain a reference state function relationship.

[0114] Step S303, calculating the heat generated by all the single cells in the battery system based on the thermal parameters of the battery system, and calculating the specific heat capacity change rate of the second single cell and the second battery capacity change rate based on the heat generated by all the single cells, and fitting the specific heat capacity change rate of the second single cell and the second battery capacity change rate to obtain a system function relationship.

[0115] Step S304 , evaluating the displayed battery system health state based on the reference state function relationship and the system function relationship, and correcting the displayed unqualified battery system health state.

[0116] Specifically, the above step S304 includes:

[0117] Step S3041, calculating a first difference between a functional relationship between a first specific heat capacity change rate and a battery health state and a first difference between a functional relationship between a second specific heat capacity change rate and a battery health state, and calculating a second difference between a functional relationship between a first single cell internal resistance and a battery health state and a second difference between a functional relationship between a second single cell internal resistance and a battery health state.

[0118] Specifically, the functional relationship between the first specific heat capacity change rate and the battery health state f(dc, SOH) or f′(dQ / dT, SOH) and the functional relationship between the second specific heat capacity change rate and the battery health state F(dc′, SOH′) or F′(dQ′ / dT′, SOH′) are subtracted to obtain a first difference δ. The schematic diagram of the functional relationship comparison between f(dc, SOH) and F(dc′, SOH′) is as shown in FIG. Figure 8 The functional relationship between the first single cell internal resistance and battery health f(R, SOH) and the functional relationship between the second single cell internal resistance and battery health F(R′, SOH′) are subtracted to obtain the second difference δ′. The comparison diagram of the functional relationship between f(R, SOH) and F(R′, SOH′) is shown in the figure. Fig. 9 shown.

[0119] Step S3042, determining whether the first difference and the second difference are within a preset error tolerance range. If so, the displayed battery system health status is deemed to have a qualified accuracy; otherwise, the displayed battery system health status is deemed to have an unqualified accuracy.

[0120] Specifically, the preset error tolerance range is set according to the actual situation and is not specifically limited here. If the first difference and the second difference are both within the preset error tolerance range, the displayed battery system health status is deemed to have qualified accuracy; if the first difference and the second difference are both not within the preset error tolerance range, the displayed battery system health status is deemed to have unqualified accuracy.

[0121] Step S3043: when the displayed battery system health status accuracy is unqualified, a preset correction coefficient or compensation method is used to correct the preset battery health status parameter model.

[0122] Specifically, the preset correction coefficient can be calculated based on the first difference and the second difference, or can be obtained based on neural network model training. The preset battery health status parameter model is corrected according to the correction coefficient to obtain a new first difference and a new second difference that meet the preset error tolerance range. The compensation method refers to directly performing difference compensation according to the first difference and the second difference, so that the first difference and the second difference meet the preset error tolerance range.

[0123] The battery health status assessment method provided in this embodiment calculates the first difference between the functional relationship between the first specific heat capacity change rate and the battery health status and the functional relationship between the second specific heat capacity change rate and the battery health status, and calculates the second difference between the functional relationship between the first single cell internal resistance and the battery health and the functional relationship between the second single cell internal resistance and the battery health; determines whether the first difference and the second difference are within the preset error allowable range, and if they are within the preset error allowable range, it is considered that the accuracy of the battery system health status is qualified; otherwise, it is considered that the accuracy of the battery system health status is unqualified, and the battery system health status is accurately judged through two judgment conditions, thereby improving the assessment accuracy and enhancing the safety performance of the battery system. When the displayed battery system health status accuracy is unqualified, a preset correction coefficient or compensation method is used to correct the preset battery health status parameter model, further improving the accuracy of the preset battery health status parameter model, thereby improving the battery health status assessment accuracy.

[0124] In this embodiment, a battery health status assessment device is also provided, which is used to implement the above-mentioned embodiments and preferred implementation modes, and will not be repeated here. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0125] This embodiment provides a battery health status assessment device, such as Fig.10 As shown, including:

[0126] The parameter acquisition module 1001 is used to acquire thermal parameters of single cells and thermal parameters of the battery system at different battery cycle numbers and set temperatures.

[0127] The reference state function calculation module 1002 is used to calculate the heat generation of the battery based on the thermal parameters of the single battery, and calculate the change rate of the specific heat capacity of the first single battery and the change rate of the first battery capacity under different battery cycle numbers based on the battery heat generation, and fit the change rate of the specific heat capacity of the first single battery and the change rate of the first battery capacity to obtain the reference state function relationship.

[0128] The system function calculation module 1003 is used to calculate the heat generated by all the single cells in the battery system based on the thermal parameters of the battery system, and calculate the specific heat capacity change rate of the second single cell and the second battery capacity change rate based on the heat generated by all the single cells, and fit the specific heat capacity change rate of the second single cell and the second battery capacity change rate to obtain a system function relationship.

[0129] The state evaluation and correction module 1004 is used to evaluate the displayed battery system health state based on the reference state function relationship and the system function relationship, and to correct the displayed unqualified battery system health state.

[0130] In some optional embodiments, the thermal parameters of the single cell battery include the specific heat capacity of the single cell battery, the temperature change of the single cell battery, and the internal resistance of the single cell battery. The reference state function calculation module 1002 includes:

[0131] The battery heat generation calculation unit is used to calculate the battery heat generation based on the specific heat capacity of the single battery and the temperature change of the single cell.

[0132] The first single cell specific heat capacity change rate calculation unit is used to perform differential calculation on the heat generated by the battery to obtain the first single cell specific heat capacity change rate.

[0133] The first battery capacity change rate calculation unit is used to obtain the discharge capacity of the single battery and the initial capacity of the single battery under different battery cycle numbers, and calculate the first battery capacity change rate based on the discharge capacity of the single battery and the initial capacity of the single battery using a preset battery health status parameter model.

[0134] The reference state functional relationship calculation unit is used to fit the first single cell specific heat capacity change rate and the first battery capacity change rate to obtain the functional relationship between the first specific heat capacity change rate and the battery health state, and simultaneously fit the single cell internal resistance and the first battery capacity change rate to obtain the functional relationship between the first single cell internal resistance and the battery health state, and use the functional relationship between the first specific heat capacity change rate and the battery health state and the functional relationship between the first single cell internal resistance and the battery health state as the reference state functional relationship.

[0135] In some optional implementations, the battery system thermal parameters include the battery system heat generation, and the system function calculation module 1003 includes:

[0136] The total single-cell battery calorific value calculation unit is used to obtain multiple other components in the battery system except all single cells; all single cells include multiple single cells; calculate the calorific value of multiple other components; calculate the calorific value of all single cells in the battery system based on the calorific value of the battery system, the calorific value of multiple other components and the number of single cells in all single cells. The second single-cell battery specific heat capacity change rate calculation unit is used to calculate the second single-cell battery specific heat capacity change rate based on the heat generated by all single cells;

[0137] A battery system parameter acquisition unit, used to acquire a second battery capacity change rate and a second single battery internal resistance calculated using a preset battery health state parameter model in the current state of the battery system;

[0138] The system function relationship calculation unit is used to fit the second single cell specific heat capacity change rate and the second battery capacity change rate to obtain the functional relationship between the second specific heat capacity change rate and the battery health state, and simultaneously fit the second single cell internal resistance and the second battery capacity change rate to obtain the functional relationship between the second single cell internal resistance and the battery health state, and use the functional relationship between the second specific heat capacity change rate and the battery health state and the functional relationship between the second single cell internal resistance and the battery health as the system function relationship.

[0139] In some optional implementations, the state assessment and correction module 1004 includes:

[0140] The difference calculation unit is used to calculate a first difference between a functional relationship between a first specific heat capacity change rate and a battery health state and a functional relationship between a second specific heat capacity change rate and a battery health state, and to calculate a second difference between a functional relationship between a first single cell internal resistance and a battery health and a functional relationship between a second single cell internal resistance and a battery health.

[0141] The judgment unit is used to judge whether the first difference and the second difference are within a preset error tolerance range. If so, the displayed battery system health status is deemed to have qualified accuracy; otherwise, the displayed battery system health status is deemed to have unqualified accuracy.

[0142] The correction unit is used to correct the preset battery health state parameter model by using a preset correction coefficient or compensation method when the displayed battery system health state accuracy is unqualified.

[0143] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0144] The battery health status assessment device in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0145] The embodiment of the present invention also provides a computer device having the above Fig.10 The battery health status assessment device shown.

[0146] See also Fig.11 , Fig.11 is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Fig.11As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Fig.11 A processor 10 is taken as an example.

[0147] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0148] The memory 20 stores instructions executable by at least one processor 10, so that the at least one processor 10 executes the method shown in the above embodiment.

[0149] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0150] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0151] The computer device also includes an input device 30 and an output device 40. The processor 10, the memory 20, the input device 30 and the output device 40 may be connected via a bus or other means. Fig.11 The example of connecting through bus is taken in the following.

[0152] The input device 30 can receive input digital or character information, and generate key signal input related to the user settings and function control of the computer device, such as a touch screen, a keypad, a mouse, a track pad, a touch pad, an indicator bar, one or more mouse buttons, a trackball, a joystick, etc. The output device 40 may include a display device, an auxiliary lighting device (e.g., an LED) and a tactile feedback device (e.g., a vibration motor), etc. The above-mentioned display device includes but is not limited to a liquid crystal display, a light emitting diode, a display and a plasma display. In some optional embodiments, the display device can be a touch screen.

[0153] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0154] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A battery health status assessment method, characterized in that: The method comprises: Obtain thermal parameters of single cells and battery systems at different battery cycle times and set temperatures; Calculating the heat generation of the battery based on the thermal parameters of the single battery, and calculating the change rate of specific heat capacity of the first single battery and the change rate of first battery capacity under different battery cycle numbers based on the heat generation of the battery, and fitting the change rate of specific heat capacity of the first single battery and the change rate of first battery capacity to obtain a reference state function relationship; Calculating the heat generated by all the single cells in the battery system based on the thermal parameters of the battery system, and calculating the specific heat capacity change rate of the second single cell and the second battery capacity change rate based on the heat generated by all the single cells, and fitting the specific heat capacity change rate of the second single cell and the second battery capacity change rate to obtain a system function relationship; The displayed battery system health state is evaluated based on the reference state function relationship and the system function relationship, and the displayed unqualified battery system health state is corrected.

2. The method according to claim 1, characterized in that: The thermal parameters of the single cell battery include the specific heat capacity of the single cell and the temperature variation of the single cell; Calculating the heat generation of the battery based on the thermal parameters of the single battery includes: The heat generation of the battery is calculated based on the specific heat capacity of the single battery and the temperature change of the single cell.

3. The method according to claim 1, characterized in that The thermal parameters of the single cell battery also include the internal resistance of the single cell battery; Calculating the specific heat capacity change rate of the first single battery and the first battery capacity change rate based on the battery heat generation, and fitting the first single battery specific heat capacity change rate and the first battery capacity change rate under different battery cycle numbers to obtain a reference state function relationship includes: Differentiating the heat generated by the battery to obtain a specific heat capacity change rate of the first single battery; Obtaining the discharge capacity of a single battery and the initial capacity of a single battery under different battery cycle numbers, and calculating the first battery capacity change rate using a preset battery health status parameter model based on the discharge capacity of the single battery and the initial capacity of the single battery; Fitting the first single cell specific heat capacity change rate and the first battery capacity change rate to obtain a functional relationship between the first specific heat capacity change rate and the battery health state, and fitting the single cell internal resistance and the first battery capacity change rate to obtain a functional relationship between the first single cell internal resistance and the battery health state; The functional relationship between the first specific heat capacity change rate and the battery health state and the functional relationship between the first single battery internal resistance and the battery health are used as reference state functional relationships.

4. The method according to claim 3, characterized in that: The battery system thermal parameters include the heat generated by the battery system; Calculating the heat generated by all single cells in the battery system based on the thermal parameters of the battery system includes: Obtain multiple other components in the battery system in addition to all single cells; Calculate the heat generated by multiple other components; The heat generated by all cells in the battery system is calculated based on the heat generated by the battery system, the heat generated by multiple other components, and the number of cells.

5. The method according to claim 4, characterized in that Calculating the second single cell specific heat capacity change rate and the second battery capacity change rate based on the heat generated by all single cells, and fitting the second single cell specific heat capacity change rate and the second battery capacity change rate to obtain a system function relationship includes: Calculate the specific heat capacity change rate of the second single battery based on the heat generated by all the single batteries; Obtaining a second battery capacity change rate and a second single battery internal resistance calculated using a preset battery health status parameter model in the current state of the battery system; Fitting the second single cell specific heat capacity change rate and the second battery capacity change rate to obtain a functional relationship between the second specific heat capacity change rate and the battery health state, and fitting the second single cell internal resistance and the second battery capacity change rate to obtain a functional relationship between the second single cell internal resistance and the battery health state; The functional relationship between the second specific heat capacity change rate and the battery health state and the functional relationship between the second single battery internal resistance and the battery health are taken as system functional relationships.

6. The method according to claim 5, characterized in that Evaluating the displayed battery system health status based on the reference state function relationship and the system function relationship includes: Calculating a first difference between a functional relationship between a first specific heat capacity change rate and a battery health state and a second functional relationship between a specific heat capacity change rate and a battery health state, and calculating a second difference between a functional relationship between a first single cell internal resistance and a battery health state and a second single cell internal resistance and a battery health state; It is determined whether the first difference and the second difference are within a preset error tolerance range. If so, the displayed battery system health status is deemed to have a qualified accuracy; otherwise, the displayed battery system health status is deemed to have an unqualified accuracy.

7. The method according to claim 6, characterized in that Correcting the displayed unqualified battery system health state includes: when the displayed battery system health state accuracy is unqualified, correcting the preset battery health state parameter model using a preset correction coefficient or compensation method.

8. A battery health status assessment device, characterized in that: The device comprises: A parameter acquisition module is used to obtain thermal parameters of single cells and battery systems at different battery cycle numbers and set temperatures; A reference state function calculation module, used to calculate the heat generation of the battery based on the thermal parameters of the single battery, and calculate the change rate of the specific heat capacity of the first single battery and the change rate of the first battery capacity under different battery cycle numbers based on the battery heat generation, and fit the change rate of the specific heat capacity of the first single battery and the change rate of the first battery capacity to obtain a reference state function relationship; a system function calculation module, used to calculate the heat generated by all the single cells in the battery system based on the thermal parameters of the battery system, and to calculate the specific heat capacity change rate of the second single cell and the second battery capacity change rate based on the heat generated by all the single cells, and to fit the specific heat capacity change rate of the second single cell and the second battery capacity change rate to obtain a system function relationship; The state evaluation module is used to evaluate the displayed battery system health state based on the reference state function relationship and the system function relationship, and to correct the displayed unqualified battery system health state.

9. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the battery health status assessment method according to any one of claims 1 to 7 by executing the computer instructions.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the battery health status assessment method according to any one of claims 1 to 7.

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