Lithium battery electrolyte performance evaluation method and device

Abstract

The invention discloses a lithium battery electrolyte performance evaluation method and device, and the method comprises the steps: assembling an electrode assembly and a to-be-tested electrolyte into a test battery monomer, the electrode assembly comprises a positive pole piece, a negative pole piece and a diaphragm located between the positive pole piece and the negative pole piece, and a positive pole material adopted by the positive pole piece is an inert conductive material; carrying out constant-voltage discharge test on the single test battery to obtain an integral electric quantity value Qe of the single test battery; according to the integral electric quantity value Qe, a performance evaluation result of the to-be-tested electrolyte is determined, and the performance evaluation result at least represents the influence degree of the to-be-tested electrolyte on the average coulombic efficiency and / or the cycle life of the single battery adopting the to-be-tested electrolyte. According to the electrolyte performance evaluation method provided by the invention, too long test time is not needed, the time cost and the labor cost required by the electrolyte performance evaluation stage are reduced, and the research and development speed of the electrolyte can be remarkably improved.

Description

Technical Field

[0001] This application belongs to the field of battery technology, specifically relating to a method and apparatus for evaluating the performance of lithium battery electrolytes. Background Technology

[0002] Lithium-ion batteries, with their remarkable high energy density, have become the core driving force supporting the development of an electric society. Their actual energy density can reach 250Wh / kg-300Wh / kg, far exceeding that of traditional lead-acid batteries, with some advanced systems even surpassing 350Wh / kg. This characteristic allows lithium-ion batteries to store more energy within a limited volume and weight, directly meeting the demand for long driving range in electric vehicles and contributing to the miniaturization and thinning of devices such as smartphones and drones. Furthermore, lithium-ion batteries possess advantages such as long cycle life, high power handling capacity, and low self-discharge rate, making them an irreplaceable energy storage medium in the electrification of transportation and the transition to cleaner energy.

[0003] In lithium-ion batteries, the electrolyte not only dominates the lithium-ion transport process but also significantly impacts the stability of the electrode / electrolyte interface. The performance of the electrolyte has a decisive influence on the battery's cycle life. Electrolytes are typically composed of high-purity lithium salts, organic solvents, and functional additives. Their physicochemical properties (such as ionic conductivity, electrochemical window, and thermal stability) and interfacial compatibility with the electrodes directly affect the cycle life, rate performance, safety performance, and operating temperature range of lithium-ion batteries. Therefore, developing high-performance electrolytes to improve the cycle life of lithium-ion batteries has always been a major focus of academia and industry.

[0004] However, current electrolyte development models are time-consuming and labor-intensive, primarily because electrolyte development heavily relies on experimental trial and error and complex performance verification processes. Current methods for evaluating electrolyte performance largely depend on battery cycling tests, including normal cycle testing, high-temperature accelerated aging testing, and battery life prediction. These methods typically require weeks to years, consuming significant time and manpower resources during the performance evaluation phase and severely slowing down electrolyte development. Summary of the Invention

[0005] This application aims to provide a method and apparatus for evaluating the performance of lithium battery electrolytes, thereby solving the problem that the performance evaluation stage of electrolyte development consumes a large amount of time and manpower, which seriously slows down the development speed of electrolytes.

[0006] To solve the above-mentioned technical problems, this application is implemented as follows: In a first aspect, embodiments of this application propose a method for evaluating the performance of a lithium battery electrolyte, comprising: assembling an electrode assembly and an electrolyte to be tested into a test battery cell, wherein the electrode assembly includes a positive electrode, a negative electrode, and a separator located between the positive and negative electrode, wherein the positive electrode material used in the positive electrode is an inert conductive material; and performing a constant voltage discharge test on the test battery cell to obtain the integrated charge value Q of the test battery cell. e Based on the integrated energy consumption value Q e The performance evaluation results of the electrolyte to be tested are determined, wherein the performance evaluation results are at least characterized as the degree of influence of the electrolyte to be tested on the average coulombic efficiency and / or cycle life of the battery cells using the electrolyte to be tested.

[0007] In some embodiments, based on the integrated energy value Q e To determine the performance evaluation results of the electrolyte to be tested, including: Battery Value Q e Condition: 60mC≤Q e If the temperature is ≤120mC, then the performance evaluation result of the electrolyte to be tested is determined to have reached the preset qualified parameters.

[0008] In some embodiments, a constant voltage discharge test is performed on the test battery cell to obtain the integrated capacity value Q of the test battery cell. e ,include: Perform constant voltage discharge tests on the individual battery cells and record the current-time curves of the individual battery cells. Based on the current-time curve, the integral charge value Q of the tested battery cell is calculated. e .

[0009] In some embodiments, the voltage range for constant voltage discharge testing is 0V-0.5V.

[0010] In some embodiments, the constant voltage discharge test lasts for 2 hours to 24 hours.

[0011] In some embodiments, the test temperature for the constant voltage discharge test is −20℃ to 150℃.

[0012] In some embodiments, a constant voltage discharge test is performed on the test battery cell to obtain the integrated capacity value Q of the test battery cell. e Previously, the methods also included: The test battery cells were left to stand for a period of time.

[0013] In some embodiments, the settling time is 4h-10h.

[0014] In some embodiments, the temperature for static treatment is 20°C-40°C.

[0015] In some embodiments, the negative electrode active material of the negative electrode sheet is at least one of elemental lithium and lithium alloy.

[0016] In some embodiments, the inert conductive material includes at least one of carbon, copper, nickel, silver, and gold.

[0017] In some embodiments, the membrane is a porous polymer membrane, which includes at least one of polyethylene membrane, polypropylene membrane, and polyethylene-polypropylene composite membrane.

[0018] Secondly, embodiments of this application propose a lithium battery electrolyte performance evaluation device, comprising: The battery cell assembly module is used to assemble the electrode assembly and the electrolyte to be tested into a test battery cell. The electrode assembly includes a positive electrode, a negative electrode, and a separator located between the positive electrode and the negative electrode. The positive electrode material used in the positive electrode is an inert conductive material. The discharge test module is used to perform constant voltage discharge tests on individual battery cells to obtain the integrated capacity value Q of the individual battery cells. e ; The performance evaluation result determination module is used to determine the integrated energy value Q. e The performance evaluation results of the electrolyte to be tested are determined, wherein the performance evaluation results are at least characterized as the degree of influence of the electrolyte to be tested on the average coulombic efficiency and / or cycle life of the battery cells using the electrolyte to be tested.

[0019] Thirdly, embodiments of this application provide an electronic device, which includes: a processor and a memory storing computer program instructions; the processor executes the computer program instructions to implement the method as described in any embodiment of the first aspect.

[0020] Fourthly, embodiments of this application provide a computer-readable storage medium storing computer program instructions that, when executed by a processor, implement the method as described in any embodiment of the first aspect.

[0021] Fifthly, embodiments of this application provide a computer program product in which instructions, when executed by a processor of an electronic device, cause the electronic device to perform the method as described in any embodiment of the first aspect.

[0022] In the lithium battery electrolyte performance evaluation method and apparatus provided in this application, after assembling the electrode assembly and the electrolyte under test into a test battery cell, a constant voltage discharge test is performed on the test battery cell. This allows the electrolyte under test to undergo controlled decomposition under constant voltage conditions, forming a solid electrolyte interphase (SEI) film. Furthermore, since the positive electrode material used is an inert conductive material and does not participate in any electrochemical reaction, the integrated charge value Q of the test battery cell measured under these conditions is... e This primarily reflects the amount of charge transferred in the electrolyte during the interfacial decomposition reaction. Therefore, the integrated charge value Q of the tested battery cell... e The larger the value, the more vigorous the reduction decomposition reaction of the electrolyte under test, consuming more active material to form an SEI, indicating poorer interfacial stability of the electrolyte under test. This negatively impacts the average coulombic efficiency and / or cycle life of the battery cell using the electrolyte under test. Conversely, a smaller value indicates a lower integral capacity Q of the battery cell. e The smaller the value, the milder the reduction decomposition reaction of the electrolyte under test, consuming less active material to form SEI. This indicates that the electrolyte under test has better interfacial stability, which will have a positive impact on the average coulombic efficiency and / or cycle life of the battery cell using the electrolyte under test.

[0023] Based on this, the integral capacity value of the tested battery cells obtained by constant-voltage discharge testing can serve as a key indicator for electrolyte performance evaluation, directly reflecting the impact of the tested electrolyte on the average coulombic efficiency and / or cycle life of the battery cells. Calculating the integral capacity value through constant-voltage discharge testing requires neither excessively long testing time nor the construction of complex testing systems, significantly shortening the testing cycle for electrolyte performance evaluation. This enables rapid screening of various electrolyte systems, reducing the time and manpower costs required in the electrolyte performance evaluation stage and contributing to a significant increase in the speed of electrolyte development.

[0024] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0025] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 A flowchart illustrating the lithium battery electrolyte performance evaluation method provided in some embodiments of this application is shown. Figure 2 An example diagram of a test battery cell structure provided in an embodiment of this application is shown; Figure 3This application provides a schematic diagram of the structure of a lithium battery electrolyte performance evaluation device according to some embodiments. Figure 4 The diagram illustrates the hardware structure of an electronic device provided in some embodiments of this application; Figure 5 This diagram illustrates the integrated charge values ​​obtained from constant voltage discharge tests on individual test cells in Embodiments 1, 2, and 3 of this application. Figure 6 This paper shows schematic diagrams illustrating the results of cycle life tests on the electrolytes to be tested in Embodiments 1, 2, and 3 of this application. Figure 7 The diagram shows the results of the average coulombic efficiency test of the electrolytes to be tested in Examples 1, 2 and 3 of this application. Detailed Implementation

[0026] The features and exemplary embodiments of various aspects of this application will now be described in detail. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain this application and are not configured to limit this application. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples of this application.

[0027] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0028] Lithium-ion batteries, with their remarkable high energy density, have become the core driving force supporting the development of an electric society. Their actual energy density can reach 250Wh / kg-300Wh / kg, far exceeding that of traditional lead-acid batteries, with some advanced systems even surpassing 350Wh / kg. This characteristic allows lithium-ion batteries to store more energy within a limited volume and weight, directly meeting the demand for long driving range in electric vehicles and contributing to the miniaturization and thinning of devices such as smartphones and drones. Furthermore, lithium-ion batteries possess advantages such as long cycle life, high power handling capacity, and low self-discharge rate, making them an irreplaceable energy storage medium in the electrification of transportation and the transition to cleaner energy.

[0029] In lithium-ion batteries, the electrolyte not only dominates the lithium-ion transport process but also significantly impacts the stability of the electrode / electrolyte interface. The performance of the electrolyte has a decisive influence on the battery's cycle life. Electrolytes are typically composed of high-purity lithium salts, organic solvents, and functional additives. Their physicochemical properties (such as ionic conductivity, electrochemical window, and thermal stability) and interfacial compatibility with the electrodes directly affect the cycle life, rate performance, safety performance, and operating temperature range of lithium-ion batteries. Therefore, developing high-performance electrolytes to improve the cycle life of lithium-ion batteries has always been a major focus of academia and industry.

[0030] However, current electrolyte development models are time-consuming and labor-intensive, primarily because electrolyte development heavily relies on experimental trial and error and complex performance verification processes. Current methods for evaluating electrolyte performance largely depend on battery cycling tests, including normal cycle testing, high-temperature accelerated aging testing, and battery life prediction. These methods typically require weeks to years, consuming significant time and manpower resources during the performance evaluation phase and severely slowing down electrolyte development.

[0031] To address the issue that the performance evaluation stage of electrolyte development in related technologies consumes significant time and manpower, severely slowing down the development speed, this application provides a lithium battery electrolyte performance evaluation method. This method eliminates the need for excessively long testing times and complex testing systems, significantly shortening the testing cycle for electrolyte performance evaluation. It also enables rapid screening of various electrolyte systems, reducing the time and manpower costs required in the electrolyte performance evaluation stage and contributing to a significant improvement in the speed of electrolyte development.

[0032] Figure 1 A flowchart illustrating the lithium battery electrolyte performance evaluation method provided in some embodiments of this application is shown. like Figure 1 As shown, the lithium battery electrolyte performance evaluation method includes steps 101 to 103.

[0033] Step 101: Assemble the electrode assembly and the electrolyte to be tested into a single test battery cell. The electrode assembly includes a positive electrode, a negative electrode, and a separator located between the positive electrode and the negative electrode. The positive electrode material used in the positive electrode is an inert conductive material.

[0034] When assembling the electrode assembly and the electrolyte under test into a single test cell, controlling the positive electrode material to be an inert conductive material ensures that the positive electrode of the test cell does not participate in the electrochemical reaction during discharge, thus eliminating the influence of the positive electrode on the electrolyte performance evaluation results. In this test cell, the electrolyte under test should wet the electrode assembly.

[0035] In addition, the test battery cell may also include a housing, which may include a positive electrode housing and a negative electrode housing. The housing may be made of steel, aluminum, nickel-plated iron, or aluminum-plastic film, etc. The motor assembly may be housed inside the housing. The test battery cell may also include other components housed inside the housing, such as gaskets and springs.

[0036] In one example, such as Figure 2 The diagram shown is an example of a test battery cell structure provided in an embodiment of this application, including a positive electrode shell 1, a positive electrode plate 2, a separator 3, a negative electrode plate 4, a gasket 5, a spring plate 6, and a negative electrode shell 7.

[0037] In some embodiments, the negative electrode active material of the negative electrode sheet is at least one of elemental lithium and lithium alloy.

[0038] In lithium-ion batteries, the reaction between the negative electrode and the electrolyte plays a decisive role in the battery's performance and stability. Specifically, during the charging and discharging process, the electrolyte forms a solid electrolyte interphase (SEI) film based on interfacial decomposition reactions. The formation of this SEI film is crucial for the long-term stability of lithium-ion batteries, as it effectively isolates lithium metal from direct contact with the electrolyte, reduces side reactions, and improves the battery's cycle life.

[0039] The standard electrode potential of lithium metal is −3.04 V vs. the standard hydrogen electrode (SHE), indicating its extremely strong reducing ability. This strong reducing property enables the electrolyte to undergo a reduction reaction on the lithium anode surface to form an SEI film with a stable electrode potential. Therefore, using at least one of elemental lithium and lithium alloys as the anode active material helps to accurately control the voltage during battery discharge, assists in detecting the degree of reduction reaction of the electrolyte on the inert electrode surface, avoids the introduction of additional influencing factors by other anode active materials, and thus accurately assesses the chemical and interfacial stability of the electrolyte.

[0040] In some embodiments, the inert conductive material includes at least one of carbon, copper, nickel, silver, and gold.

[0041] Inert conductive materials include at least one of carbon, copper, nickel, silver, and gold. They can give the positive electrode good conductivity while also having high chemical stability, avoiding chemical reactions between the positive electrode material and the electrolyte. This ensures that during constant voltage discharge, only the electrochemical reaction of the electrolyte being reduced by electrons on the surface of the positive electrode material occurs, which helps to reduce errors generated during constant voltage discharge testing and thus improves the accuracy of electrolyte performance evaluation.

[0042] In some embodiments, the membrane is a porous polymer membrane, which includes at least one of polyethylene membrane, polypropylene membrane, and polyethylene-polypropylene composite membrane.

[0043] Porous polymer membranes can provide flow channels for electrolytes based on their pore structure, thereby improving the wetting of electrolytes on the electrode surface and enabling electrolytes to permeate the electrode surface uniformly. This provides a stable interfacial environment for the reduction and decomposition reaction of electrolytes at the negative electrode interface, helps to reduce errors generated during constant voltage discharge testing, and thus improves the accuracy of electrolyte performance evaluation.

[0044] In some embodiments, assembling the electrode assembly with the electrolyte under test into a test battery cell includes: Under inert atmosphere conditions, the electrode assembly and the electrolyte to be tested are assembled into a single test battery cell.

[0045] Assembling the electrode assembly and the electrolyte under test into a single test battery cell under inert atmosphere conditions can prevent the electrolyte under test and even the electrode assembly from reacting with certain components in the air and introducing additional interference factors. This helps to reduce the error generated during constant voltage discharge testing and thus improves the accuracy of electrolyte performance evaluation.

[0046] Step 102: Perform a constant voltage discharge test on the test battery cell to obtain the integrated capacity value Q of the test battery cell. e .

[0047] Constant voltage discharge testing of the test battery cell allows for controlled decomposition of the electrolyte under constant voltage conditions, forming a solid electrolyte interphase (SEI) film. Furthermore, since the positive electrode material is an inert conductive material and does not participate in any electrochemical reaction, the integrated charge value Q of the test battery cell is measured under these conditions. e This primarily reflects the amount of charge transferred in the electrolyte during the interfacial decomposition reaction. Therefore, the integrated charge value Q of the tested battery cell... eThe larger the value, the more vigorous the reduction decomposition reaction of the electrolyte under test, consuming more active material to form an SEI, indicating poorer interfacial stability of the electrolyte under test. This negatively impacts the average coulombic efficiency and / or cycle life of the battery cell using the electrolyte under test. Conversely, a smaller value indicates a lower integral capacity Q of the battery cell. e The smaller the value, the milder the reduction decomposition reaction of the electrolyte under test, consuming less active material to form SEI. This indicates that the electrolyte under test has better interfacial stability, which will have a positive impact on the average coulombic efficiency and / or cycle life of the battery cell using the electrolyte under test.

[0048] Based on this, the integral charge value of the test battery cell obtained by constant voltage discharge test can be used as a key indicator for electrolyte performance evaluation, which can intuitively reflect the degree of influence of the electrolyte under test on the average coulombic efficiency and / or cycle life of the battery cell.

[0049] In some embodiments, a constant voltage discharge test is performed on the test battery cell to obtain the integrated capacity value Q of the test battery cell. e ,include: Perform constant voltage discharge tests on the individual battery cells and record the current-time curves of the individual battery cells. Based on the current-time curve, the integral charge value Q of the tested battery cell is calculated. e .

[0050] In practical applications, the current-time (It) curve can be recorded during the constant voltage discharge test, and then the integrated charge value Q of the tested battery cell can be calculated based on the current-time curve. e Specifically, the integral energy value Q e The calculation can be performed using the following formula: Q e =∫Idt Where I is the current and t is the time.

[0051] In some embodiments, the voltage range for constant voltage discharge testing is 0V-0.5V.

[0052] Controlling the voltage range to 0V-0.5V helps to cause controlled decomposition of the electrolyte under test. Within this voltage range, the reduction decomposition reaction of the electrolyte under test on the surface of the inert electrode to generate a solid electrolyte interface film will be the main electrochemical reaction, which helps to reduce the occurrence of side reactions and improve the accuracy of electrolyte performance evaluation.

[0053] In some embodiments, the constant voltage discharge test lasts for 2 hours to 24 hours.

[0054] The constant voltage discharge test time is controlled between 2h and 24h to obtain sufficient data to calculate the integrated charge value Q. e， It can also avoid excessively long testing time, thus extending the testing cycle of electrolyte performance evaluation, which helps to achieve rapid screening of various electrolyte systems, reduce the time and manpower costs required in the electrolyte performance evaluation stage, and significantly improve the speed of electrolyte research and development.

[0055] If the test time is too short, the reduction and decomposition reaction of the electrolyte at the negative electrode interface may not be sufficient, which may result in the test results failing to reflect the true performance of the electrolyte under test. If the test time is too long, it may cause excessive reaction or unnecessary side reaction, affecting the reliability of electrolyte performance evaluation.

[0056] In some embodiments, the test temperature for the constant voltage discharge test is −20℃ to 150℃.

[0057] The constant voltage discharge test has a test temperature range of −20℃ to 150℃, which can test the performance changes of electrolytes under different temperature conditions. This helps to screen out electrolyte systems with stronger environmental adaptability and improve the accuracy and comprehensiveness of electrolyte performance evaluation.

[0058] In practical applications, constant voltage discharge testing can be conducted within the above temperature range under constant temperature conditions to avoid excessive temperature changes that could reduce the accuracy of electrolyte performance evaluation.

[0059] In some embodiments, a constant voltage discharge test is performed on the test battery cell to obtain the integrated capacity value Q of the test battery cell. e Previously, the methods also included: The test battery cells were left to stand for a period of time.

[0060] In practical applications, before performing constant voltage discharge tests on individual test cells, the assembled test cells can be left to stand for a period of time to allow the electrolyte to fully wet the electrode components, thereby further improving the accuracy of electrolyte performance evaluation.

[0061] In some embodiments, the settling time is 4h-10h.

[0062] The settling time is controlled to 4-10 hours, which allows the electrolyte to completely and uniformly penetrate the battery electrode components, especially between the electrodes and the separator. This helps eliminate electrolyte distribution problems caused by uneven electrolyte injection or the presence of air bubbles, thereby further improving the accuracy of electrolyte performance evaluation.

[0063] In some embodiments, the temperature for static treatment is 20°C-40°C.

[0064] The temperature control of the static treatment is 20℃-40℃, which helps to improve the fluidity and permeability of the electrolyte, so that the electrolyte can fully wet the electrode assembly and further improve the accuracy of electrolyte performance evaluation.

[0065] Step 103, based on the accumulated power value Q e The performance evaluation results of the electrolyte to be tested are determined, wherein the performance evaluation results are at least characterized as the degree of influence of the electrolyte to be tested on the average coulombic efficiency and / or cycle life of the battery cells using the electrolyte to be tested.

[0066] In practical applications, the integral capacity value of a single battery cell obtained through constant-voltage discharge testing can serve as a key indicator for electrolyte performance evaluation. It directly reflects the impact of the tested electrolyte on the average coulombic efficiency and / or cycle life of the battery cell. Calculating the integral capacity value through constant-voltage discharge testing requires neither excessively long testing times nor the construction of complex testing systems, significantly shortening the testing cycle for electrolyte performance evaluation. This enables rapid screening of various electrolyte systems, reducing the time and manpower costs required in the electrolyte performance evaluation stage and contributing to a significant acceleration of electrolyte development.

[0067] In some embodiments, based on the integrated energy value Q e To determine the performance evaluation results of the electrolyte to be tested, including: Battery Value Q e Condition: 60mC≤Q e If the temperature is ≤120mC, then the performance evaluation result of the electrolyte to be tested is determined to have reached the preset qualified parameters.

[0068] In practical applications, in order to determine the integral energy value Q e The performance evaluation results of the electrolyte under test can be obtained intuitively. Multiple tests and calibrations can be performed to obtain the integral capacity value Q of the battery cell using the electrolyte under test, provided that the average coulombic efficiency and / or cycle life meet the qualified standards. e The actual range should be determined in order to form quantitative judgment rules for electrolyte performance evaluation, thereby improving the accuracy and efficiency of electrolyte performance evaluation.

[0069] In one example, it was experimentally calibrated that the integrated energy value Q could be achieved. e Condition: 60mC≤Q e When the temperature is ≤120mC, the performance evaluation result of the electrolyte under test is determined to meet the preset qualified parameters. That is, it is determined that the electrolyte under test will have a sufficient positive impact on the average coulombic efficiency and / or cycle life of the battery cell using the electrolyte under test, and the performance evaluation result of the electrolyte under test is determined to be qualified. Based on this, the integral charge value Q can be considered qualified. eThe closer the actual value is to the lower limit of 60mC, the greater the positive impact of the electrolyte under test on the average coulombic efficiency and / or cycle life of the battery cell using the electrolyte under test.

[0070] In this example, when the integrated energy value Q e A temperature of ≤60mC may indicate that the electrolyte cannot effectively form an SEI, which could negatively impact the average coulombic efficiency and / or cycle life of the battery cells. Alternatively, it may indicate a significant error during testing, requiring retesting.

[0071] In this example, when the integrated energy value Q e At a temperature ≥120mC, the electrolyte can be considered to have a negative impact on the average coulombic efficiency and / or cycle life of the battery cells using the electrolyte under test. Based on this, the integral charge value Q can be considered... e The further the actual value is from the upper limit of 120mC, the greater the negative impact of the electrolyte under test on the average coulombic efficiency and / or cycle life of the battery cell using the electrolyte under test.

[0072] In some embodiments, based on the integrated energy value Q e To determine the performance evaluation results of the electrolyte to be tested, including: Obtain the baseline integrated capacity value, which is the integrated capacity value obtained when a test battery cell assembled with a baseline electrolyte and electrode assembly is subjected to a constant voltage discharge test; wherein, the baseline electrolyte is an electrolyte whose performance evaluation results are qualified; Based on the accumulated energy value Q e The performance evaluation result of the electrolyte under test is determined by comparing it with the baseline integrated charge value.

[0073] In practical applications, an electrolyte that is generally considered to have a significant positive impact on the average coulombic efficiency and / or cycle life of a battery cell can be selected from existing electrolyte systems as the benchmark electrolyte to be tested. For example, a 1.6 mol / L lithium difluorosulfonylimide-ethylene glycol dimethyl ether-1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether electrolyte can be used to construct a test battery cell based on the benchmark electrolyte to conduct a constant voltage discharge test and obtain the benchmark integrated charge value.

[0074] After obtaining the baseline integrated energy value, the integrated energy value Q can be used as a basis for calculation. e The performance evaluation result of the electrolyte under test is determined by comparing it with the baseline integrated charge value. For example, the integrated charge value corresponding to the electrolyte under test can be 60mC≤Q. e If the integral charge value is less than or equal to the baseline integral charge value, the performance evaluation result of the electrolyte under test is deemed to be qualified, and based on this, the corresponding integral charge value Q of the electrolyte under test can be determined.e The further the actual value is from the baseline integrated charge value, the better the performance evaluation result of the electrolyte under test.

[0075] A performance judgment range can also be set based on a benchmark integral energy value, for example, it can be 60mC≤Q e When the integral charge value is less than or equal to the baseline integral charge value * N, the performance evaluation result of the electrolyte under test is deemed to be qualified, and based on this, the corresponding integral charge value Q of the electrolyte under test can be determined. e The further the actual value is from the baseline integrated charge value * N, the better the performance evaluation result of the electrolyte under test. Here, N is a pre-set range coefficient, and the value of N should be ≥1, so as to appropriately expand the judgment range of the quantitative judgment rule based on the baseline integrated charge value and improve the accuracy of electrolyte performance evaluation.

[0076] In some embodiments, the electrolyte to be tested may include a lithium salt, which may include one or more of lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium trifluoromethanesulfonate (LiTFS), lithium difluorooxalate borate (LiDFOB), lithium dioxalate borate (LiBOB), lithium difluorophosphate (LiPO2F2), lithium difluorodioxalate phosphate (LiDFOP), and lithium tetrafluorooxalate phosphate (LiTFOP). Other lithium salts may also be included, and the specific selection can be made according to actual testing requirements.

[0077] In some embodiments, the electrolyte to be tested may include a solvent, which may include one or more of cyclic carbonate solvents, chain carbonate solvents, carboxylic acid ester solvents, ether solvents, nitrile solvents, and sulfone solvents.

[0078] As an example, the solvent may include, but is not limited to, one or more of the following: ethylene carbonate (EC), propylene carbonate (PC), methyl ethyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), butyl ester carbonate (BC), methyl formate (MF), methyl acetate (MA), ethyl acetate (EA), propyl acetate (PA), methyl propionate (MP), ethyl propionate (EP), propyl propionate (PP), methyl butyrate (MB), ethyl butyrate (EB), 1,4-butyrolactone (GBL), sulfolane (SF), dimethyl sulfone (MSM), methyl ethyl sulfone (EMS), diethyl sulfone (ESE), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ether. The specific choice can be made based on actual testing needs.

[0079] In some embodiments, the concentration of the electrolyte salt can be between 0.6 mol / L and 4 mol / L, for example, it can be 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L, 1 mol / L, 1.1 mol / L, 1.2 mol / L, 1.3 mol / L, 1.4 mol / L, 1.5 mol / L, 1.6 mol / L, 1.7 mol / L, 1.8 mol / L, 1.9 mol / L, 2 mol / L, 2.2 mol / L, 2.4 mol / L, 2.6 mol / L, 2.8 mol / L, 3 mol / L, 3.2 mol / L, 3.4 mol / L, 3.6 mol / L, 3.8 mol / L, 4 mol / L, or any range of the above values. Those skilled in the art can adjust the concentration of the electrolyte salt according to actual testing needs.

[0080] In some embodiments, the electrolyte to be tested may include additives. For example, the additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain properties of a secondary battery cell, such as additives that improve overcharge performance, additives that improve high-temperature performance, additives that improve low-temperature performance, etc.

[0081] As an example, additives may include, but are not limited to, one or more of ethylene carbonate (VC), vinylene carbonate (VEC), fluoroethylene carbonate (FEC), hexamethyldisilazane (HMDS), 2,2,5,5-tetramethyl-2,5-disil-1-hexaoxane (TMDS), trioxymethylene (TO), ethylene sulfate (DTD), lithium difluorophosphate (LiPO2F2), lithium bis(oxalato)borate (LiBOB), lithium difluorooxalato)borate (LiDFOB), cyclohexylbenzene (CHB), biphenyl (BP), trimethyl phosphate (TMP), triphenyl phosphate (TPP), and lithium nitrate (LiNO3).

[0082] In some embodiments, the electrolyte to be tested may include a diluent, which may include, but is not limited to, one or more of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE), 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether (TFTFE), fluorobenzene (FB), and trifluorotoluene (BTF).

[0083] Figure 3 A schematic diagram of the structure of a lithium battery electrolyte performance evaluation device provided for some embodiments of this application is shown; Please see Figure 3 The lithium battery electrolyte performance evaluation device 300 includes: a battery cell assembly test module 310, a discharge test module 320, and a performance evaluation result determination module 330.

[0084] The battery cell assembly module 310 is used to assemble the electrode assembly and the electrolyte to be tested into a test battery cell. The electrode assembly includes a positive electrode, a negative electrode, and a separator located between the positive electrode and the negative electrode. The positive electrode material used in the positive electrode is an inert conductive material. The discharge test module 320 is used to perform constant voltage discharge tests on the test battery cells to obtain the integrated capacity value Q of the test battery cells. e ; The performance evaluation result determination module 330 is used to determine the integrated power consumption value Q. e The performance evaluation results of the electrolyte to be tested are determined, wherein the performance evaluation results are at least characterized as the degree of influence of the electrolyte to be tested on the average coulombic efficiency and / or cycle life of the battery cells using the electrolyte to be tested.

[0085] In some embodiments, the performance evaluation result determination module 330 includes: The qualification judgment module is used to determine the accumulated power consumption value Q. e Condition: 60mC≤Q e If the temperature is ≤120mC, then the performance evaluation result of the electrolyte to be tested is determined to meet the preset qualified parameters.

[0086] In some embodiments, the discharge test module 320 includes: The discharge test submodule is used to perform constant voltage discharge tests on individual test cells and record the current-time curve of the individual test cells. The integrated capacity calculation module is used to calculate the integrated capacity value Q of the tested battery cell based on the current-time curve. e。

[0087] In some embodiments, the apparatus further includes: The static treatment module is used to statically process the test battery cells.

[0088] In some embodiments, the test battery cell assembly module 310 includes: The battery cell assembly submodule is used to assemble electrode components and the electrolyte under test into a test battery cell under inert atmosphere conditions.

[0089] Figure 4 A schematic diagram of the hardware structure of an electronic device provided for some embodiments of this application is shown.

[0090] Please see Figure 4 An electronic device may include a processor 401 and a memory 402 storing computer program instructions.

[0091] Specifically, the processor 401 may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0092] Memory 402 may include mass storage for data or instructions. For example, and not limitingly, memory 402 may include a hard disk drive (HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 402 may include removable or non-removable (or fixed) media. Where appropriate, memory 402 may be internal or external to the integrated gateway disaster recovery device. In a particular embodiment, memory 402 is non-volatile solid-state memory.

[0093] Memory may include read-only memory (ROM), random access memory (RAM), disk storage media devices, optical storage media devices, flash memory devices, and electrical, optical, or other physical / tangible memory storage devices. Therefore, typically, memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the methods according to one aspect of this disclosure.

[0094] The processor 401 reads and executes computer program instructions stored in the memory 402 to implement any of the electrolyte performance evaluation methods in the above embodiments.

[0095] In one example, the electronic device may also include a communication interface 403 and a bus 410. For example, Figure 4 As shown, the processor 401, memory 402, and communication interface 403 are connected through bus 410 and complete communication with each other.

[0096] Communication interface 403 is primarily used to enable communication between modules, devices, units, and / or equipment in the embodiments of this application. Bus 410 includes hardware, software, or both, that couples components of the online data traffic metering device together. For example, and not limitingly, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 410 may include one or more buses. Although specific buses are described and illustrated in the embodiments of this application, this application contemplates any suitable bus or interconnect.

[0097] This electronic device can perform the electrolyte performance evaluation method in the embodiments of this application, thereby achieving the combination Figure 1 The method for evaluating electrolyte performance is described.

[0098] Furthermore, in conjunction with the electrolyte performance evaluation methods in the above embodiments, this application embodiment can provide a computer-readable storage medium for implementation. This computer-readable storage medium stores computer program instructions; when these computer program instructions are executed by a processor, they implement any of the electrolyte performance evaluation methods in the above embodiments.

[0099] Based on the electrolyte performance evaluation methods in the above embodiments, this application can provide a computer program product for implementation. When the instructions in the computer program product are executed by the processor of an electronic device, they implement any of the electrolyte performance evaluation methods in the above embodiments.

[0100] It should be clarified that this application is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0101] The functional blocks shown in the above structural diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored in a computer-readable storage medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Computer-readable storage medium" can include any medium capable of storing or transmitting information. Examples of computer-readable storage media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0102] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0103] The above are merely specific embodiments of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

[0104] The beneficial effects of the electrolyte performance evaluation method provided in this application will be illustrated by the following examples.

[0105] Example 1 This embodiment provides a method for evaluating the performance of lithium battery electrolytes, including: Step 1: Assemble the electrode assembly and the electrolyte to be tested into a single test battery cell. The electrode assembly includes a positive electrode, a negative electrode, and a separator located between the positive electrode and the negative electrode. The positive electrode material used in the positive electrode is an inert conductive material. Specifically, such as Figure 2 As shown, the positive electrode shell 1, positive electrode 2, separator 3, negative electrode 4, gasket 5, spring 6 and negative electrode shell 7 can be assembled into a test battery cell. The positive electrode inert material used in the positive electrode is nickel foil, the negative electrode active material in the negative electrode is lithium, the separator is a polyethylene separator, and the composition of the electrolyte to be tested includes 1.0 mol / L LiPF6-FEC / DMC. Step 2: Perform a constant voltage discharge test on the test battery cell to obtain the integrated capacity value Q of the test battery cell. e ; Specifically, the test battery cell can be subjected to a constant voltage discharge test at 0V for 10 hours to induce controlled decomposition of the electrolyte and formation of a solid electrolyte interphase (SEI) film. During this constant voltage discharge process, high-precision current monitoring equipment is used to collect discharge current data in real time, and the discharge time is integrated to obtain the integrated charge value Q of the test battery cell. e .

[0106] Step 3, based on the accumulated battery value Q e The performance evaluation results of the electrolyte to be tested are determined, wherein the performance evaluation results are at least characterized as the degree of influence of the electrolyte to be tested on the average coulombic efficiency and / or cycle life of the battery cells using the electrolyte to be tested. Specifically, it can be done through the integrated power consumption value Q. e Condition: 60mC≤Q e When the temperature is ≤120mC, the performance evaluation result of the electrolyte under test is determined to meet the preset qualified parameters. That is, it is determined that the electrolyte under test will have a sufficient positive impact on the average coulombic efficiency and / or cycle life of the battery cell using the electrolyte under test, and the performance evaluation result of the electrolyte under test is determined to be qualified. Based on this, the integral charge value Q can be considered qualified. e The closer the actual value is to the lower limit of 60mC, the greater the positive impact of the electrolyte under test on the average coulombic efficiency and / or cycle life of the battery cell using the electrolyte under test.

[0107] Example 2 The difference between this embodiment and Embodiment 1 is that the composition of the electrolyte to be tested is different. Specifically, the composition of the electrolyte to be tested in this embodiment includes 1.6 mol / L LiFSI-DME-TTE.

[0108] Example 3 The difference between this embodiment and Embodiment 1 is that the composition of the electrolyte to be tested is different. Specifically, the composition of the electrolyte to be tested in this embodiment includes: 1.6 mol / L LiFSI-DME-TTE + 2 wt.% TMDS.

[0109] The integrated charge values ​​obtained from the constant voltage discharge test of the test cells in Examples 1, 2, and 3 are as follows: Figure 5 As shown.

[0110] Performance verification test: Cycle life test: Based on the use of nickel-cobalt-manganese ternary cathode material as the cathode material and rolled lithium foil as the anode material, button batteries 1, 2, and 3 were assembled using the electrolytes from Examples 1, 2, and 3, respectively. Cycle life tests were then conducted on button batteries 1, 2, and 3. The assembled button batteries underwent charge-discharge tests at specific current and capacity densities on a temperature-controlled charge-discharge apparatus. During the battery cycle test, the charge-discharge capacity of the button battery continuously decreased due to SEI growth, dead lithium accumulation, and electrolyte decomposition and drying. The battery was considered to have failed when it reached 80% of its initial capacity. The number of cycles at this point was defined as the battery's cycle life. The results of the cycle life tests on the electrolytes from Examples 1, 2, and 3 are as follows: Figure 6 As shown.

[0111] Average Coulombic Efficiency Test: Based on using copper foil as the positive electrode material and rolled lithium foil as the negative electrode material, button batteries 4, 5, and 6 were assembled using the electrolytes from Examples 1, 2, and 3, respectively; and the average coulombic efficiency of button batteries 4, 5, and 6 was tested. The assembled button batteries were subjected to charge-discharge tests at specific current and capacity densities on a temperature-controlled charge-discharge apparatus. During battery discharge, deposited lithium metal reacts with the electrolyte to produce SEI, therefore the charging capacity upon recharging is less than the discharging capacity. The coulombic efficiency of a single charge-discharge cycle is calculated by dividing the charging capacity by the discharging capacity. The average coulombic efficiency is calculated as the average coulombic efficiency of the same battery from the 1st to the 30th charge-discharge cycle. The results of the average coulombic efficiency tests of the electrolytes from Examples 1, 2, and 3 are as follows: Figure 7 As shown.

[0112] based on Figures 5-7The test results corresponding to Examples 1, 2, and 3 can be summarized in Table 1: Table 1

[0113] As can be seen from Table 1, the integrated capacity value Q of the tested battery cell... e Condition: 60mC≤Q e At ≤120mC, the electrolyte under test in the tested battery cell will have a significant positive impact on the average coulombic efficiency and / or cycle life of the battery cell using the tested electrolyte, and based on this, the integral charge value Q e The closer the actual value is to the lower limit of 60mC, the greater the positive impact of the electrolyte under test on the average coulombic efficiency and / or cycle life of the battery cells using the electrolyte under test.

[0114] In the lithium battery electrolyte performance evaluation method and apparatus provided in this application, after assembling the electrode assembly and the electrolyte under test into a test battery cell, a constant voltage discharge test is performed on the test battery cell. This allows the electrolyte under test to undergo controlled decomposition under constant voltage conditions, forming a solid electrolyte interphase (SEI) film. Furthermore, since the positive electrode material used is an inert conductive material and does not participate in any electrochemical reaction, the integrated charge value Q of the test battery cell measured under these conditions is... e This primarily reflects the amount of charge transferred during the decomposition reaction of the electrolyte on the surface of the positive electrode. Therefore, the integrated charge value Q of a single battery cell is... e The larger the value, the more vigorous the reduction decomposition reaction of the electrolyte under test, consuming more active material to form an SEI, indicating poorer interfacial stability of the electrolyte under test. This negatively impacts the average coulombic efficiency and / or cycle life of the battery cell using the electrolyte under test. Conversely, a smaller value indicates a lower integral capacity Q of the battery cell. e The smaller the value, the milder the reduction decomposition reaction of the electrolyte under test, consuming less active material to form SEI. This indicates that the electrolyte under test has better interfacial stability, which will have a positive impact on the average coulombic efficiency and / or cycle life of the battery cell using the electrolyte under test.

[0115] Based on this, the integral capacity value of the tested battery cells obtained by constant-voltage discharge testing can serve as a key indicator for electrolyte performance evaluation, directly reflecting the impact of the tested electrolyte on the average coulombic efficiency and / or cycle life of the battery cells. Calculating the integral capacity value through constant-voltage discharge testing requires neither excessively long testing time nor the construction of complex testing systems, significantly shortening the testing cycle for electrolyte performance evaluation. This enables rapid screening of various electrolyte systems, reducing the time and manpower costs required in the electrolyte performance evaluation stage and contributing to a significant increase in the speed of electrolyte development.

[0116] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0117] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for evaluating the performance of lithium battery electrolytes, characterized in that, include: The electrode assembly and the electrolyte to be tested are assembled into a test battery cell. The electrode assembly includes a positive electrode, a negative electrode, and a separator located between the positive electrode and the negative electrode. The positive electrode material used in the positive electrode is an inert conductive material. performing a constant-voltage discharge test on the test battery cell to obtain an integrated electric quantity value Q of the test battery cell e ; According to the integrated electric quantity value Q e , determine the performance evaluation result of the to-be-tested electrolyte, wherein the performance evaluation result is at least represented as an influence degree of the to-be-tested electrolyte on the average coulombic efficiency and / or the cycle life of the battery cell using the to-be-tested electrolyte.

2. The electrolyte performance evaluation method according to claim 1, characterized in that, According to the integrated electric quantity value Q e , determining the performance evaluation result of the to-be-tested electrolyte, comprising: The integral electric quantity value Q e Satisfying the condition: 60mC≤Q e ≤120mC, it is determined that the performance evaluation result of the to-be-tested electrolyte reaches the preset calibrated qualified parameter.

3. The electrolyte performance evaluation method according to claim 1, characterized in that, performing a constant-voltage discharge test on the test battery cell to obtain an integrated electric quantity value Q of the test battery cell e comprising: A constant voltage discharge test was performed on the test battery cell, and the current-time curve of the test battery cell was recorded. Based on the current-time curve, the integral charge value Q of the tested battery cell is calculated. e .

4. The electrolyte performance evaluation method according to claim 3, characterized in that, The method satisfies one or more of the following conditions: (1) The voltage range of the constant voltage discharge test is 0V-0.5V; (2) The constant voltage discharge test lasts for 2 hours to 24 hours; (3) The test temperature for the constant voltage discharge test is −20℃-150℃.

5. The electrolyte performance evaluation method according to claim 1, characterized in that, The test battery cell was subjected to a constant voltage discharge test to obtain the integrated charge value Q of the test battery cell. e Previously, the method also included: The test battery cells were left to stand for a period of time.

6. The electrolyte performance evaluation method according to claim 5, characterized in that, The method satisfies one or more of the following conditions: (1) The settling time is 4h-10h; (2) The temperature of the static treatment is 20℃-40℃.

7. The electrolyte performance evaluation method according to claim 1, characterized in that, Assemble the electrode assembly and the electrolyte under test into a single test battery cell, including: Under inert atmosphere conditions, the electrode assembly and the electrolyte to be tested are assembled into the test battery cell.

8. The electrolyte performance evaluation method according to claim 1, characterized in that, The electrode assembly satisfies one or more of the following conditions: (1) The negative electrode active material of the negative electrode sheet is at least one of elemental lithium and lithium alloy; (2) The inert conductive material includes at least one of carbon, copper, nickel, silver and gold; (3) The membrane is a porous polymer membrane, which includes at least one of polyethylene membrane, polypropylene membrane and polyethylene-polypropylene composite membrane.

9. A lithium battery electrolyte performance evaluation device, characterized in that, include: A test battery cell assembly module is used to assemble an electrode assembly and an electrolyte to be tested into a test battery cell. The electrode assembly includes a positive electrode, a negative electrode, and a separator located between the positive electrode and the negative electrode. The discharge test module is used to perform a constant voltage discharge test on the test battery cell to obtain the integrated capacity value Q of the test battery cell. e ; The performance evaluation result determination module is used to determine the integrated power consumption value Q based on the integrated power consumption value Q. e The performance evaluation results of the electrolyte under test are determined, wherein the performance evaluation results are at least characterized as the degree of influence of the electrolyte under test on the average coulombic efficiency and / or cycle life of the battery cells using the electrolyte under test.

10. An electronic device, characterized in that, include: Processor and memory storing computer program instructions; When the processor executes the computer program instructions, it implements the electrolyte performance evaluation method as described in any one of claims 1-8.

11. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer program instructions, which, when executed by a processor, implement the electrolyte performance evaluation method as described in any one of claims 1-8.

12. A computer program product, characterized in that, When the instructions in the computer program product are executed by the processor of the electronic device, the electronic device performs the electrolyte performance evaluation method as described in any one of claims 1-8.

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