CN116973793A - Lithium battery health state monitoring and evaluating method, system, equipment and medium - Google Patents
Lithium battery health state monitoring and evaluating method, system, equipment and medium Download PDFInfo
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- 230000036541 health Effects 0.000 title claims abstract description 71
- 238000000034 method Methods 0.000 title claims abstract description 68
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 title claims abstract description 65
- 229910052744 lithium Inorganic materials 0.000 title claims abstract description 65
- 238000012544 monitoring process Methods 0.000 title claims abstract description 53
- 238000012937 correction Methods 0.000 claims abstract description 57
- 238000005259 measurement Methods 0.000 claims abstract description 35
- 230000007613 environmental effect Effects 0.000 claims abstract description 32
- 230000036760 body temperature Effects 0.000 claims abstract description 31
- 238000011156 evaluation Methods 0.000 claims abstract description 25
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims abstract description 23
- 229910001416 lithium ion Inorganic materials 0.000 claims abstract description 23
- 230000032683 aging Effects 0.000 claims description 27
- 230000008859 change Effects 0.000 claims description 20
- 230000003862 health status Effects 0.000 claims description 18
- 125000004122 cyclic group Chemical group 0.000 claims description 17
- 238000003860 storage Methods 0.000 claims description 16
- 238000004590 computer program Methods 0.000 claims description 12
- 238000001816 cooling Methods 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 7
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical group [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 claims description 6
- 230000003068 static effect Effects 0.000 claims description 6
- QHGJSLXSVXVKHZ-UHFFFAOYSA-N dilithium;dioxido(dioxo)manganese Chemical compound [Li+].[Li+].[O-][Mn]([O-])(=O)=O QHGJSLXSVXVKHZ-UHFFFAOYSA-N 0.000 claims description 3
- 206010005908 Body temperature conditions Diseases 0.000 claims description 2
- 229910000625 lithium cobalt oxide Inorganic materials 0.000 claims description 2
- BFZPBUKRYWOWDV-UHFFFAOYSA-N lithium;oxido(oxo)cobalt Chemical compound [Li+].[O-][Co]=O BFZPBUKRYWOWDV-UHFFFAOYSA-N 0.000 claims description 2
- 238000007599 discharging Methods 0.000 description 13
- 238000001514 detection method Methods 0.000 description 12
- 230000008569 process Effects 0.000 description 12
- 238000010586 diagram Methods 0.000 description 8
- 230000010354 integration Effects 0.000 description 8
- 238000012545 processing Methods 0.000 description 7
- 230000006870 function Effects 0.000 description 5
- 238000000691 measurement method Methods 0.000 description 5
- 238000002474 experimental method Methods 0.000 description 4
- 239000000178 monomer Substances 0.000 description 4
- 238000009529 body temperature measurement Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000013075 data extraction Methods 0.000 description 1
- 238000012983 electrochemical energy storage Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 238000012216 screening Methods 0.000 description 1
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Abstract
The application belongs to the technical field of battery state monitoring and evaluation, and discloses a lithium battery health state monitoring and evaluation method, a system, equipment and a medium; the method comprises the following steps: acquiring the working environment temperature, the battery body temperature and the capacity measured value of the lithium battery to be monitored and evaluated in the state of health; correcting the capacity measurement value based on the acquired working environment temperature and the battery body temperature to obtain a capacity correction value; and acquiring a health state monitoring and evaluating result of the lithium battery to be subjected to health state monitoring and evaluating based on the acquired capacity correction value. According to the application, the battery temperature and the environmental temperature of the lithium ion battery are monitored and analyzed in real time, the measured capacity of the battery is corrected according to the battery temperature and the environmental temperature, and the lithium battery health state monitoring and evaluating result is obtained based on the corrected capacity, so that the error of the battery capacity can be reduced, and the accuracy of the battery health state evaluation is improved.
Description
Technical Field
The application belongs to the technical field of battery state monitoring and evaluation, and particularly relates to a lithium battery health state monitoring and evaluation method, system, equipment and medium.
Background
The electrochemical energy storage technology is widely applied to the fields of micro-grids, new energy power generation, electric automobiles, industrial production and the like.
At present, the commonly used battery voltage is generally lower, and the battery voltage needs to be connected in series to form groups when in use, and is influenced by factors such as a battery processing production process and the like, and certain inconsistency exists among battery monomers; in addition, in the use process, the working environments of all the battery monomers are not completely the same, so that the inconsistency is further amplified; the above situation reduces the state of health of the battery, and the actual capacity of the battery pack often depends on the worst cell performance, which greatly reduces the capacity of the battery pack. Therefore, when the battery pack works, various parameters of different battery monomers need to be monitored in time, unhealthy battery monomers in the battery pack are found in time, and a battery health state monitoring and evaluating result is obtained.
In the prior art, battery health status monitoring and evaluation are generally carried out on the basis of obtaining battery capacity; the method is characterized in that an ampere-hour integration method is directly adopted when the battery capacity is measured, and the environment temperature and the battery temperature are not considered; however, the capacity of the battery fluctuates within a certain range under different ambient temperatures and battery temperatures, so that errors occur in battery capacity measurement, and finally, the evaluation result of the battery health state is not accurate enough.
Disclosure of Invention
The application aims to provide a lithium battery health state monitoring and evaluating method, system, equipment and medium, which are used for solving one or more of the technical problems. According to the technical scheme provided by the application, the battery temperature and the environmental temperature of the lithium ion battery are monitored and analyzed in real time, the measured capacity of the battery is corrected according to the battery temperature and the environmental temperature, the lithium battery health state monitoring and evaluating result is obtained based on the corrected capacity, the error of the battery capacity can be reduced, and the accuracy of the battery health state evaluation is improved.
In order to achieve the above purpose, the application adopts the following technical scheme:
the application provides a lithium battery health state monitoring and evaluating method, which comprises the following steps:
acquiring the working environment temperature, the battery body temperature and the capacity measured value of the lithium battery to be monitored and evaluated in the state of health;
correcting the capacity measurement value based on the acquired working environment temperature and the battery body temperature to obtain a capacity correction value;
and acquiring a health state monitoring and evaluating result of the lithium battery to be subjected to health state monitoring and evaluating based on the acquired capacity correction value.
The method of the present application is further improved in that the step of correcting the capacity measurement value based on the obtained operating environment temperature and the battery body temperature to obtain a capacity correction value specifically includes:
based on the battery body temperature, determining to obtain a battery state; the battery state is that the battery is in a static state, in a steady state operation state or in a high-frequency operation state;
if the battery is in a static state, according to Q A ＝aT A +b+cQ m Calculating to obtain a capacity correction value of the battery; wherein Q is m Is a measure of the capacity of the battery; a. b, c are fitting coefficients selected according to the cycle times of the lithium battery to be monitored and evaluated according to the state of health; t (T) A To the working environment temperature, Q A A capacity correction value for the battery;
if the battery is in a steady state operation state, according to Q B ＝dT B +e+fQ n Calculating to obtain a capacity correction value of the battery; wherein Q is n Is a measure of the capacity of the battery; d. e, f are fitting coefficients selected according to the cycle times of the lithium battery to be monitored and evaluated according to the state of health; t (T) B To the working environment temperature, Q B A capacity correction value for the battery;
if the battery is in a high-frequency working state, according to Q 3 ＝(aT A +b+cQ m )×50％+(dT B +e+fQ n ) Calculating the x 50% to obtain the corrected capacity of the battery; q (Q) 3 Is the capacity correction value of the battery.
The method of the application is further improved in that the step of judging to obtain the battery state based on the battery body temperature specifically comprises the following steps:
based on the fluctuation condition of the battery body temperature in a preset time period, the battery state is judged to be obtained.
The method of the application is further improved in that the step of obtaining the fitting coefficients a, b, c comprises the steps of:
selecting and grouping a plurality of brand new lithium ion batteries with the same model as the lithium battery to be monitored and evaluated in the health state to obtain a plurality of battery packs; respectively carrying out cyclic aging charge and discharge operations of different times on each battery pack;
measuring and obtaining the capacity of each single battery in each battery pack after the cyclic aging charge-discharge operation at the room temperature of 25 ℃; placing each battery pack under a plurality of preset environmental temperature conditions different from room temperature, and carrying out capacity measurement on each single battery in each battery pack again;
taking the battery capacity at room temperature of 25 ℃ as a reference value, performing linear fitting on different preset environmental temperatures, different battery aging degrees and change data of the battery capacity at different environmental temperatures to obtain a linear relation between the battery capacity and the environmental temperature of the battery, wherein the expression is Q 1 ＝aT 1 +b+cQ x Obtaining fitting coefficients a, b and c;
wherein Q is x For measuring the capacity of the battery at different preset environmental temperatures, T 1 At ambient temperature, Q 1 Is the battery capacity measured at room temperature of 25 ℃.
The method of the application is further improved in that the step of obtaining the fitting coefficients d, e and f comprises the following steps:
selecting and grouping a plurality of brand new lithium ion batteries with the same model as the lithium battery to be monitored and evaluated in the health state to obtain a plurality of battery packs; respectively carrying out cyclic aging charge and discharge operations of different times on each battery pack;
placing each battery pack at room temperature of 25 ℃, standing the battery until the temperature of the battery is not changed any more, and measuring the capacity of the battery;
heating or cooling each battery pack to a plurality of preset battery body temperature conditions, and carrying out capacity measurement on each single battery in each battery pack again; based on the battery capacity data obtained by re-carrying out capacity measurement, carrying out linear fitting on different battery body temperatures, different battery aging degrees and capacity change data of the battery at different battery body temperatures to obtain a linear relation between the battery capacity and the battery body temperature, wherein the expression is Q 2 ＝dT 2 +e+fQ y Obtaining fitting coefficients d, e and f;
wherein Q is y For measuring capacity of battery, T 2 To the temperature of the battery body, Q 2 The corrected battery capacity.
The method of the application is further improved in that the step of obtaining the health state monitoring and evaluating result of the lithium battery to be monitored and evaluated based on the obtained capacity correction value specifically comprises the following steps:
and calculating according to the capacity correction value to obtain the state of health SOH of the battery, and obtaining the state of health monitoring and evaluating result of the lithium battery to be monitored and evaluated based on the state of health SOH.
The method is further improved in that the lithium battery is a lithium iron phosphate battery, a ternary lithium battery, a lithium cobalt oxide battery or a lithium manganate battery.
The second aspect of the present application provides a lithium battery health status monitoring and evaluating system, comprising:
the data acquisition module is used for acquiring the working environment temperature, the battery body temperature and the capacity measured value of the lithium battery to be monitored and evaluated in the state of health;
the correction module is used for correcting the capacity measurement value based on the acquired working environment temperature and the acquired battery body temperature to obtain a capacity correction value;
and the evaluation module is used for acquiring the health state monitoring evaluation result of the lithium battery to be subjected to health state monitoring evaluation based on the acquired capacity correction value.
An electronic device provided in a third aspect of the present application includes:
at least one processor; the method comprises the steps of,
a memory communicatively coupled to the at least one processor; wherein,,
the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the lithium battery state of health monitoring assessment method according to any one of the first aspects of the present application.
A fourth aspect of the present application provides a computer-readable storage medium storing a computer program, which when executed by a processor implements the lithium battery health status monitoring and assessment method according to any one of the first aspects of the present application.
Compared with the prior art, the application has the following beneficial effects:
the application provides a battery health state evaluation method considering the environment temperature and the battery temperature, which considers the influence condition of the environment temperature on the battery capacity accounting when the battery is in different working environment temperatures and also considers the influence of the body temperature of the battery on the battery capacity measurement value when the battery is in the working state; the measured battery capacity can be corrected based on the ambient temperature or the battery temperature, so that the battery capacity measurement error at different ambient temperatures and battery temperatures is effectively reduced; and based on the corrected capacity, a lithium battery health state monitoring and evaluating result is obtained, and the evaluation accuracy of the battery health state can be improved.
In the application, considering that the battery possibly has a plurality of states including a stable running state, a standing state and a high-frequency working state, different capacity correction schemes are provided for different working states of the battery, and the accuracy of the capacity correction of the battery can be further improved.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following description of the embodiments or the drawings used in the description of the prior art will make a brief description; it will be apparent to those of ordinary skill in the art that the drawings in the following description are of some embodiments of the application and that other drawings may be derived from them without undue effort.
Fig. 1 is a schematic flow chart of a method for monitoring and evaluating the health status of a lithium battery according to an embodiment of the present application;
fig. 2 is a schematic flow chart of a method for monitoring and evaluating the health status of a lithium battery, which considers the ambient temperature and the battery temperature in the embodiment of the application;
FIG. 3 is a schematic diagram of a table recording experimental temperature and capacity data in an embodiment of the present application;
fig. 4 is a schematic diagram of a lithium battery health status monitoring and evaluating system according to an embodiment of the present application.
Detailed Description
In order that those skilled in the art will better understand the present application, a technical solution in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present application without making any inventive effort, shall fall within the scope of the present application.
It should be noted that the terms "first," "second," and the like in the description and the claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the application described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The application is described in further detail below with reference to the attached drawing figures:
referring to fig. 1, a method for monitoring and evaluating a health state of a lithium battery according to an embodiment of the present application includes the following steps:
step 1, acquiring a working environment temperature, a battery body temperature and a capacity measured value of a lithium battery to be monitored and evaluated in a health state;
step 2, correcting the capacity measurement value based on the working environment temperature and the battery body temperature obtained in the step 1 to obtain a capacity correction value;
and step 3, acquiring a health state monitoring and evaluating result of the lithium battery to be subjected to health state monitoring and evaluating based on the capacity correction value acquired in the step 2.
In the technical scheme provided by the embodiment of the application, the influence condition of the environment temperature on the battery capacity accounting when the battery is in different working environment temperatures is considered, and the influence of the body temperature of the battery on the battery capacity measured value when the battery is in a working state is also considered; the measured battery capacity can be corrected based on the ambient temperature or the battery temperature, so that the battery capacity measurement error at different ambient temperatures and battery temperatures is effectively reduced; the lithium battery health state monitoring and evaluating result is obtained based on the corrected capacity, so that the evaluation accuracy of the battery health state can be improved; and then can realize the timely discovery of low health state battery and the screening of different health state batteries, promote the circulation capacity and the life of group battery.
In still another embodiment of the present application, in step 1, the step of obtaining the working environment temperature includes:
and acquiring the environmental temperature change condition in a preset time period by using a temperature acquisition device, and taking an average value to obtain the final working environmental temperature. Further exemplary, for different environmental characteristics, temperature acquisition devices are arranged on the upper and lower sides and parallel directions of the battery, and environmental temperature change conditions within 10 minutes are acquired and averaged to provide a reference for correcting the measured capacity of the battery.
In still another embodiment of the present application, in step 1, the step of obtaining the temperature of the battery body includes:
and acquiring the temperature change condition of the battery body in a preset time period by using a temperature acquisition device, and taking an average value to obtain the final temperature of the battery body. Further exemplary, a battery temperature acquisition device is used, and for the characteristics of different batteries, temperature sensing devices are attached to six sides of the battery, so as to acquire the environmental temperature change condition within 10 minutes, and judge the running state of the battery. When the battery capacity detection and correction module is used for measuring the capacity of the battery, the battery temperature acquisition device is responsible for measuring the temperature change condition of the battery in the capacity measurement process and calculating the average value of the battery temperature change condition so as to provide data reference for correcting the capacity of the battery.
In still another embodiment of the present application, in step 1, the step of obtaining the capacity measurement value includes:
the battery capacity detection device is used, an ampere-hour integration method is used as a theoretical basis, and a small current is used for measuring the capacity of the battery to obtain a capacity measurement value.
In yet another embodiment of the present application, step 2 specifically includes the following steps:
if the battery is in a static state, the battery is in accordance with formula Q A ＝aT A +b+cQ m Calculating to obtain a capacity correction value of the battery; wherein Q is m Is a measure of the capacity of the battery; a. b and c are fitting coefficients selected according to the cycle times of the battery to be tested; t (T) A To the working environment temperature, Q A A capacity correction value for the battery; wherein the working environment temperature T A Is obtained and the capacity measurement value Q of the battery m The measurement method of (2) is the same as that in the above-mentioned step 1;
if the battery is in a steady state operation state, the battery is in accordance with formula Q B ＝dT B +e+fQ n Calculating a capacity correction value of the battery; wherein Q is n Is a measure of the capacity of the battery; d. e, f are pre-acquired fitting coefficients selected according to the cycle times of the battery to be tested; t (T) B To the working environment temperature, Q B A capacity correction value for the battery; wherein the working environment temperature T B Is obtained and the capacity measurement value Q of the battery n The determination of (2) is the same as described in step 1;
if the battery is in a high-frequency working state, comprehensively adopting a lithium ion battery capacity correction method considering the ambient temperature and a lithium ion battery capacity correction method considering the battery temperature, and according to a formula Q 3 ＝(aT A +b+cQ m )×50％+(dT B +e+fQ n ) Calculating the correction capacity of the battery by x 50%; q (Q) 3 The corrected battery capacity.
In a further embodiment of the present application, the step of obtaining the fitting coefficients a, b, c includes:
selecting a plurality of new lithium ion batteries with the same model as the lithium battery to be monitored and evaluated in a health state, and grouping to obtain a plurality of groups of battery packs; respectively carrying out cyclic aging charge and discharge operations of different times on each group of battery packs; the specific example is that 25 new lithium ion batteries are selected, 5 batteries are taken as a group, the batteries are divided into 5 groups, and the battery groups are respectively subjected to 200 times, 400 times, 600 times, 800 times and 1000 times of cyclic aging charge and discharge operations; the method comprises the steps of firstly charging the battery capacity to a charge cut-off voltage with the rated current of the battery, and then discharging the battery to a discharge cut-off voltage with the rated current, wherein the specified one-time cyclic aging charge-discharge operation is that the battery capacity is charged to the charge cut-off voltage with the rated current of the battery;
measuring and obtaining the capacity of each single battery in each battery pack after the cyclic aging charge-discharge operation at the room temperature of 25 ℃; in a specific example, each group of batteries is firstly placed under the condition of room temperature of 25 ℃, and each single battery in the battery group is subjected to capacity measurement and recording, wherein the capacity measurement method is defined that firstly, the battery is discharged to a discharge cut-off voltage by using a small current of 0.1C, then the battery is charged to a charge cut-off voltage by using the current of 0.1C, the purpose of charging and discharging by using the small current of 0.1C is to reduce the influence of the temperature change of the battery on an experiment result in the charging and discharging process, and the capacity of the battery is calculated by using an ampere-hour integration method, so that a relatively accurate battery capacity Q is obtained 1 ；
Placing each group of batteries at 0 ℃,10 ℃,20 ℃,30 ℃,40 ℃ and 50 ℃ respectively, and re-measuring and recording the capacity of each single battery in each battery group; taking the battery capacity at the room temperature of 25 ℃ as a reference value, performing linear fitting on different preset environmental temperatures, different battery aging degrees and change data of the battery capacity at different environmental temperatures to establish a linear relation Q between the battery capacity and the environmental temperature of the battery 1 ＝aT 1 +b+cQ x Obtaining fitting coefficients a, b and c; wherein Q is x For measuring capacity of the battery at different ambient temperatures, T 1 At ambient temperature, Q 1 Is the battery capacity measured at room temperature of 25 ℃; illustratively, batteries of different degrees of aging have different fitting coefficients.
In the embodiment of the application, a brand-new lithium ion battery is selected, cyclic charge-discharge aging operations are performed for different times, the capacity of the lithium ion battery is measured at room temperature, then the lithium ion battery is placed at other different environmental temperatures, and the capacity of the lithium ion battery is measured, so that a method capable of correcting the measured capacity of the lithium ion battery which is at different environmental temperatures and has different aging degrees is provided, and the error of measuring the capacity of the lithium ion battery at different environmental temperatures is reduced by the method.
In the embodiment of the application, the steps of obtaining the fitting coefficients d, e and f comprise the following steps:
selecting a plurality of new lithium ion batteries with the same model as the lithium battery to be monitored and evaluated in a health state, and grouping to obtain a plurality of groups of battery packs; respectively carrying out cyclic aging charge and discharge operations of different times on each group of battery packs; the specific operation mode can be the same as that in the steps of obtaining the fitting coefficients a, b and c;
placing each group of batteries at room temperature of 25 ℃, standing the batteries until the temperature of the batteries is not changed any more, measuring the capacity of the batteries and recording; the specified capacity measurement method comprises the steps of firstly discharging a battery to a discharge cut-off voltage by using a small current of 0.05C, then charging the battery to a charge cut-off voltage by using a current of 0.05C, further reducing the influence of the temperature change of the battery on an experimental result in the charge and discharge process by using the purpose of charging and discharging the small current of 0.05C, and calculating the capacity of the battery by using an ampere-hour integration method to obtain a relatively accurate battery capacity;
heating or cooling each group of batteries to 0 ℃,10 ℃,20 ℃,30 ℃,40 ℃ and 50 ℃ by using a battery heating or cooling device, and carrying out capacity measurement and recording on each single battery in the battery group again; according to the recorded battery capacity data, linear fitting is carried out on different battery body temperatures, different battery aging degrees and capacity change data of the battery at different battery body temperatures, and a linear relation Q between battery capacity and battery temperature is established 2 ＝dT 2 +e+fQ y Obtaining fitting coefficients d, e, f, wherein Q y For measuring capacity of battery, T 2 For battery temperature, Q 2 The corrected battery capacity.
In the embodiment of the application, brand-new lithium ion batteries are selected, different times of cyclic charge-discharge aging operation are carried out on different lithium ion batteries, the capacity of the lithium ion batteries is measured at room temperature, the single batteries are heated or cooled to different temperatures through a battery heating or cooling device, and then the capacity of the batteries is measured.
In another embodiment of the present application, the step 3 of performing health status monitoring and evaluation on the lithium battery to obtain a health status evaluation result includes the following steps:
and calculating the state of health SOH of the battery according to the corrected battery capacity of the battery, wherein when the SOH of the battery is more than 90%, the state of health of the battery is set to be excellent, 80% -90% is good, 70% -80% is good, and less than 70% is bad.
In summary, the technical solution of the embodiment of the present application is specifically an evaluation method for evaluating the health status of a multi-parameter battery by considering the environmental temperature, which specifically considers the influence of the environmental temperature of the environment where the battery is located on the battery capacity during the battery capacity accounting, thereby improving the evaluation accuracy of the health status of the battery; the influence condition of the battery temperature of the battery on the battery capacity during the battery capacity accounting is considered, so that the evaluation accuracy of the battery health state is improved; in addition, by analyzing the running state of the battery, different correction methods are adopted for the batteries in different running states, so that the working efficiency and correction accuracy of battery capacity correction are improved.
Further exemplary embodiments of the present application provide that the battery cells in the battery pack may be lithium iron phosphate batteries, ternary lithium batteries, lithium cobaltate batteries, lithium manganate batteries, and the like.
Further exemplary embodiments of the present application provide an ambient temperature acquisition process comprising: and (3) adopting an accurate thermometer for experiments, placing the thermometer in six directions of six sides of the battery, wherein the directions are one meter away from the battery, measuring the ambient temperature within 10 minutes at intervals of 1 minute when the ambient temperature of the battery begins to be measured, measuring ten ambient temperature data, calculating the average value of the ambient temperature according to the ten ambient temperature data, transmitting the average value to a battery capacity detecting and correcting device, and extracting the ambient temperature data again for 10 minutes if the ambient temperature changes too much.
Further exemplary embodiments of the present application provide a battery temperature acquisition process comprising: the accurate temperature sensor for experiments is adopted to be attached to six sides of the battery, and when the measurement of the battery temperature is started, the battery temperature within 10 minutes is measured at the measurement interval of 1 minute and is transmitted to the battery capacity detection and correction device; when the battery capacity detection and correction device starts to measure the capacity of the battery to be measured, the battery temperature acquisition device records the battery temperature of the battery to be measured at intervals of half a minute, and when the capacity measurement is finished, the temperature measurement is stopped at the same time, and the average value of the battery temperature in the time range of the battery capacity measurement is calculated and transmitted to the battery capacity detection and correction device.
Further exemplary embodiments of the present application determine that a battery state is obtained based on a fluctuation of a battery temperature within a preset time period. Specifically, the battery operation state is determined by the temperature change within 10 minutes of the battery acquired by the battery temperature acquisition device: if the temperature of the battery is less than 2 ℃ within 10 minutes, judging that the battery is in a standing state; if the temperature fluctuation range of the battery is within plus or minus 5 ℃, judging that the battery is in a steady state operation state; and if the temperature fluctuation range of the battery exceeds plus or minus 10 ℃, judging that the battery is in a high-frequency working state.
In summary, in the technical scheme provided by the embodiment of the application, the ampere-hour integration method is adopted to measure the capacity of the battery, the battery is charged to the battery charging cut-off voltage with a small current of 0.1C, and then the battery is discharged to the discharging cut-off voltage with a small current of 0.1C, and the formula Q= Special 0 t Mu Idt is used for calculating the total discharge capacity of the battery, wherein mu is the discharge efficiency, and I is the discharge current; the battery capacity correction device corrects the battery capacity measured by the battery capacity detection device according to the determined battery working state, the corrected reference ambient temperature is the collected ambient temperature average value, and the referenced battery temperature is the calculated temperature average value in the process of measuring the battery capacity, specificallyThe capacity correction method comprises the following steps: if the battery is in a static state, the battery is in accordance with formula Q T ＝aT A +b+cQ calculates the corrected capacity of the battery, where Q T The corrected battery capacity; if the battery is in a steady state operation state, the battery is in accordance with formula Q T ＝dT B +e+fQ calculates the corrected capacity of the battery; if the battery is in a high-frequency working state, the battery is in a high-frequency working state according to a formula Q T ＝(aT A +b+cQ)×50％+(dT B +e+fQ). Times.50% to calculate the corrected capacity of the battery; the battery capacity can be corrected to obtain more accurate battery capacity, and the accurate health state of the battery can be further calculated.
Referring to fig. 2 and 3, in an embodiment of the present application, a lithium iron phosphate battery is taken as an example, the rated voltage of the lithium iron phosphate battery is 3.2V, the rated capacity is 20AH, the ohmic resistance is about 1.5mΩ, the charge cut-off voltage is 3.65V, the discharge cut-off voltage is 2.3V, and the maximum discharge current is 3-5C;
summarizing a lithium ion battery capacity correction method considering ambient temperature, the method comprises: selecting 25 new lithium iron phosphate batteries, taking 5 batteries as a group, dividing the batteries into 5 groups, respectively performing 200 times, 400 times, 600 times, 800 times and 1000 times of cyclic aging charge and discharge operation on the battery groups, and prescribing the cyclic aging charge and discharge operation for one time as follows: (1) Standing the battery for 30s after the experiment is started, so that the battery is stable and reaches electrochemical balance in the state; (2) Discharging to the discharge cut-off voltage of 2.8V by constant current of 20A, and standing for 30min to stabilize the battery and reach the electrochemical balance in the state; (3) Then charging to the battery charge cut-off voltage of 3.65V with the constant current of 20A, and standing for 30min to stabilize the battery and reach the electrochemical balance in the state; then placing each group of batteries at room temperature of 25 ℃ at first, and carrying out capacity measurement and recording on each single battery in the battery group, wherein the capacity measurement method is defined as that firstly, 0.1C small current is used for discharging the batteries to a discharge cut-off voltage, then 0.1C current is used for charging the batteries to a charge cut-off voltage, the purpose of charging and discharging the batteries with 0.1C small current is to reduce the influence of the temperature change of the batteries on experimental results in the charging and discharging process, and then an ampere-hour integration method is used for calculating the capacity of the batteries to obtain relatively accurate battery capacity; finally, each group of batteries is placed at the temperature of 0 ℃,10 ℃,20 ℃,30 ℃,40 ℃ and 50 ℃ under the environmental temperature condition, capacity measurement is carried out again on each single battery in the battery group and recorded, and data under different environmental temperature conditions are respectively prepared into a table, as shown in figure 3; according to the recorded battery capacity data, taking the battery capacity at the room temperature of 25 ℃ as a reference value, performing linear fitting on battery capacity change data with different aging degrees and environment temperature data thereof under different environment temperatures, and establishing a linear relation between the battery capacity and the environment temperature of the battery;
further summarized is a lithium ion battery capacity correction method taking battery temperature into account, comprising: selecting 25 new lithium ion batteries, taking 5 batteries as a group, dividing the batteries into 5 groups, and respectively performing 200 times, 400 times, 600 times, 800 times and 1000 times of cyclic aging charge and discharge operations on the battery groups, wherein the cyclic aging charge and discharge operations are specified in the step 1; then placing each group of batteries at room temperature of 25 ℃, standing the batteries until the temperature of the batteries is not changed any more, measuring and recording the capacity of the batteries, wherein the specified capacity measuring method is that firstly, 0.05C small current is used for discharging the batteries to a discharge cut-off voltage, then 0.05C small current is used for charging the batteries to a charge cut-off voltage, the purpose of charging and discharging the batteries with 0.05C small current is to further reduce the influence of the temperature change of the batteries on experimental results in the charging and discharging process, and then an ampere-hour integration method is used for calculating the capacity of the batteries to obtain relatively accurate battery capacity; finally, heating or cooling each group of batteries to 0 ℃,10 ℃,20 ℃,30 ℃,40 ℃ and 50 ℃ by using a battery heating or cooling device, re-measuring and recording the capacity of each single battery in the battery group, and respectively preparing data under different environmental temperature conditions into a table, wherein an example is shown in fig. 3; according to the recorded battery capacity data, performing linear fitting on battery capacity change data and environment temperature data thereof at different battery temperatures and different ageing degrees, and establishing a linear relation between battery capacity and battery temperature;
when the battery capacity detection device starts to detect the capacity of the battery to be detected, the environment temperature acquisition device starts to measure the environment temperature of the battery, measures the environment temperature within 10 minutes at intervals of 1 minute, measures ten pieces of environment temperature data, calculates the average value of the environment temperature according to the ten pieces of environment temperature data and transmits the average value to the battery capacity detection and correction device, and if the environment temperature changes too much, the environment temperature data extraction is carried out again for 10 minutes. The battery capacity detection and correction device judges the running state of the battery according to the temperature change of the battery within 10 minutes acquired by the battery temperature acquisition device: if the temperature of the battery is less than 2 ℃ within 10 minutes, judging that the battery is in a standing state; if the temperature fluctuation range of the battery is within plus or minus 5 ℃, judging that the battery is in a steady state operation state; if the temperature fluctuation range of the battery exceeds plus or minus 10 ℃, judging that the battery is in a high-frequency working state;
and then the battery capacity detection device measures the battery capacity by adopting an ampere-hour integration method, when the battery capacity detection and correction device starts to measure the capacity of the battery to be measured, the battery temperature acquisition device records the battery temperature of the battery to be measured at intervals of half a minute, and when the capacity measurement is finished, the temperature measurement is stopped at the same time, and the average value of the battery temperature in the time range of the battery capacity measurement is calculated and transmitted to the battery capacity detection and correction device. The capacity measurement method comprises the following steps: firstly, the battery is charged to the battery charge cut-off voltage with a small current of 0.1C, and then the battery is discharged to the discharge cut-off voltage with a small current of 0.1C, and the formula Q= Special is used 0 t Mu Idt calculates the total discharge capacity of the battery, where mu is the discharge efficiency and I is the discharge current.
According to the technical scheme provided by the embodiment of the application, the environmental temperature and the battery temperature are considered as influencing factors influencing the measurement of the battery capacity, and the capacities of the single batteries in different temperature states can be corrected by eliminating the influence of the environmental temperature and the battery temperature on the battery capacity, so that the health state of the battery can be accurately calculated.
The following are device embodiments of the present application that may be used to perform method embodiments of the present application. For details not disclosed in the apparatus embodiments, please refer to the method embodiments of the present application.
Referring to fig. 4, in still another embodiment of the present application, a lithium battery health status monitoring and evaluating system is provided, including:
the data acquisition module is used for acquiring the working environment temperature, the battery body temperature and the capacity measured value of the lithium battery to be monitored and evaluated in the state of health;
the correction module is used for correcting the capacity measurement value based on the acquired working environment temperature and the acquired battery body temperature to obtain a capacity correction value;
and the evaluation module is used for acquiring the health state monitoring evaluation result of the lithium battery to be subjected to health state monitoring evaluation based on the acquired capacity correction value.
In yet another embodiment of the present application, a computer device is provided that includes a processor and a memory for storing a computer program including program instructions, the processor for executing the program instructions stored by the computer storage medium. The processor may be a central processing unit (Central Processing Unit, CPU), but may also be other general purpose processor, digital signal processor (Digital Signal Processor, DSP), application specific integrated circuit (Application Specific Integrated Circuit, ASIC), off-the-shelf programmable gate array (Field-Programmable Gate Array, FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components, etc., which are the computational core and control core of the terminal adapted to implement one or more instructions, in particular to load and execute one or more instructions within a computer storage medium to implement a corresponding method flow or a corresponding function; the processor provided by the embodiment of the application can be used for the operation of the lithium battery health state monitoring and evaluating method.
In yet another embodiment of the present application, a storage medium, specifically a computer readable storage medium (Memory), is a Memory device in a computer device, for storing a program and data. It is understood that the computer readable storage medium herein may include both built-in storage media in a computer device and extended storage media supported by the computer device. The computer-readable storage medium provides a storage space storing an operating system of the terminal. Also stored in the memory space are one or more instructions, which may be one or more computer programs (including program code), adapted to be loaded and executed by the processor. The computer readable storage medium herein may be a high-speed RAM memory or a non-volatile memory (non-volatile memory), such as at least one magnetic disk memory. One or more instructions stored in a computer-readable storage medium may be loaded and executed by a processor to implement the corresponding steps of the method for monitoring and evaluating the health of a lithium battery in the above embodiments.
It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
Finally, it should be noted that: the above embodiments are only for illustrating the technical aspects of the present application and not for limiting the same, and although the present application has been described in detail with reference to the above embodiments, it should be understood by those of ordinary skill in the art that: modifications and equivalents may be made to the specific embodiments of the application without departing from the spirit and scope of the application, which is intended to be covered by the claims.
Claims (10)
1. The lithium battery health state monitoring and evaluating method is characterized by comprising the following steps of:
acquiring the working environment temperature, the battery body temperature and the capacity measured value of the lithium battery to be monitored and evaluated in the state of health;
correcting the capacity measurement value based on the acquired working environment temperature and the battery body temperature to obtain a capacity correction value;
and acquiring a health state monitoring and evaluating result of the lithium battery to be subjected to health state monitoring and evaluating based on the acquired capacity correction value.
2. The method for monitoring and evaluating the health status of a lithium battery according to claim 1, wherein the step of correcting the capacity measurement value based on the obtained operating environment temperature and the battery body temperature to obtain a capacity correction value specifically comprises:
based on the battery body temperature, determining to obtain a battery state; the battery state is that the battery is in a static state, in a steady state operation state or in a high-frequency operation state;
if the battery is in a static state, according to Q A ＝aT A +b+cQ m Calculating to obtain a capacity correction value of the battery; wherein Q is m Is a measure of the capacity of the battery; a. b, c are fitting coefficients selected according to the cycle times of the lithium battery to be monitored and evaluated according to the state of health; t (T) A To the working environment temperature, Q A A capacity correction value for the battery;
if the battery is in a steady state operation state, according to Q B ＝dT B +e+fQ n Calculating to obtain a capacity correction value of the battery; wherein Q is n Is a measure of the capacity of the battery; d. e, f are fitting coefficients selected according to the cycle times of the lithium battery to be monitored and evaluated according to the state of health; t (T) B To the working environment temperature, Q B A capacity correction value for the battery;
if the battery is in a high-frequency working state, according to Q 3 ＝(aT A +b+cQ m )×50％+(dT B +e+fQ n ) Calculating the x 50% to obtain the corrected capacity of the battery; q (Q) 3 Is the capacity correction value of the battery.
3. The method for monitoring and evaluating the health status of a lithium battery according to claim 2, wherein the step of determining the battery status based on the battery body temperature specifically comprises:
based on the fluctuation condition of the battery body temperature in a preset time period, the battery state is judged to be obtained.
4. The method for monitoring and evaluating the health status of a lithium battery according to claim 2, wherein the step of obtaining the fitting coefficients a, b, c comprises:
selecting and grouping a plurality of brand new lithium ion batteries with the same model as the lithium battery to be monitored and evaluated in the health state to obtain a plurality of battery packs; respectively carrying out cyclic aging charge and discharge operations of different times on each battery pack;
measuring and obtaining the capacity of each single battery in each battery pack after the cyclic aging charge-discharge operation at the room temperature of 25 ℃; placing each battery pack under a plurality of preset environmental temperature conditions different from room temperature, and carrying out capacity measurement on each single battery in each battery pack again;
taking the battery capacity at room temperature of 25 ℃ as a reference value, performing linear fitting on different preset environmental temperatures, different battery aging degrees and change data of the battery capacity at different environmental temperatures to obtain a linear relation between the battery capacity and the environmental temperature of the battery, wherein the expression is Q 1 ＝aT 1 +b+cQ x Obtaining fitting coefficients a, b and c;
wherein Q is x For measuring the capacity of the battery at different preset environmental temperatures, T 1 At ambient temperature, Q 1 Is the battery capacity measured at room temperature of 25 ℃.
5. The method for monitoring and evaluating the health status of a lithium battery according to claim 2, wherein the step of obtaining the fitting coefficients d, e, f comprises:
selecting and grouping a plurality of brand new lithium ion batteries with the same model as the lithium battery to be monitored and evaluated in the health state to obtain a plurality of battery packs; respectively carrying out cyclic aging charge and discharge operations of different times on each battery pack;
placing each battery pack at room temperature of 25 ℃, standing the battery until the temperature of the battery is not changed any more, and measuring the capacity of the battery;
heating or cooling each battery pack to a plurality of preset battery body temperature conditions, and carrying out capacity measurement on each single battery in each battery pack again; based on the battery capacity data obtained by re-carrying out capacity measurement, carrying out capacity change data of batteries at different battery body temperatures, different battery aging degrees and different battery body temperaturesLinear fitting to obtain linear relation between battery capacity and battery body temperature, and the expression is Q 2 ＝dT 2 +e+fQ y Obtaining fitting coefficients d, e and f;
wherein Q is y For measuring capacity of battery, T 2 To the temperature of the battery body, Q 2 The corrected battery capacity.
6. The method for monitoring and evaluating the health state of a lithium battery according to claim 1, wherein the step of obtaining the health state monitoring and evaluating result of the lithium battery to be monitored and evaluated based on the obtained capacity correction value specifically comprises:
and calculating according to the capacity correction value to obtain the state of health SOH of the battery, and obtaining the state of health monitoring and evaluating result of the lithium battery to be monitored and evaluated based on the state of health SOH.
7. The method for monitoring and evaluating the health status of a lithium battery according to claim 1, wherein the lithium battery is a lithium iron phosphate battery, a ternary lithium battery, a lithium cobalt oxide battery or a lithium manganate battery.
8. A lithium battery state of health monitoring and assessment system, comprising:
the data acquisition module is used for acquiring the working environment temperature, the battery body temperature and the capacity measured value of the lithium battery to be monitored and evaluated in the state of health;
the correction module is used for correcting the capacity measurement value based on the acquired working environment temperature and the acquired battery body temperature to obtain a capacity correction value;
and the evaluation module is used for acquiring the health state monitoring evaluation result of the lithium battery to be subjected to health state monitoring evaluation based on the acquired capacity correction value.
9. An electronic device, comprising:
at least one processor; the method comprises the steps of,
a memory communicatively coupled to the at least one processor; wherein,,
the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the lithium battery health status monitoring assessment method of any one of claims 1 to 7.
10. A computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the lithium battery health status monitoring and assessment method according to any one of claims 1 to 7.
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| CN117688398A (en) * | 2023-12-08 | 2024-03-12 | 杭州兴达通信有限公司 | Electric energy metering box early warning management system based on Internet of things |
| CN118294836A (en) * | 2024-03-04 | 2024-07-05 | 深圳市瑞能电源科技有限公司 | Battery pack health monitoring method and device, computer equipment and storage medium |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN117688398A (en) * | 2023-12-08 | 2024-03-12 | 杭州兴达通信有限公司 | Electric energy metering box early warning management system based on Internet of things |
| CN118294836A (en) * | 2024-03-04 | 2024-07-05 | 深圳市瑞能电源科技有限公司 | Battery pack health monitoring method and device, computer equipment and storage medium |
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