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A rapid prediction method for cycle life of lithium-ion batteries

A lithium-ion battery, cycle life technology, applied in the direction of prediction, measurement of electricity, measurement device, etc., can solve the problems of large deviation of test results, high test cost, shortening, etc., achieve good consistency, reduce test time, and reduce test cost Effect

Inactive Publication Date: 2021-12-31
CHINA ELECTRONICS STANDARDIZATION INST +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Various standards require that after 500 cycles according to the conventional rate (0.2C, C is the current capacity), the battery capacity should not be lower than 80% of the rated capacity, but to complete 500 tests, take a 1000mAh battery as an example, at least 7 batteries are required Months, time-consuming, high cost of testing, seriously hindering the further development and application of lithium-ion batteries
[0004] The existing accelerated test method tests the short-term cycle performance of different cycle times, records the number of cycles and the corresponding capacity retention rate, and uses the mass difference subtraction method to calculate the electrolyte retention rate of the battery after the cycle. According to the number of cycles, capacity retention rate and Fitting calculation of electrolyte retention rate to predict battery life. Compared with conventional cycle life test, the cycle test cycle is shortened, but the test result has a large deviation (>5%), and other similar problems also exist

Method used

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  • A rapid prediction method for cycle life of lithium-ion batteries
  • A rapid prediction method for cycle life of lithium-ion batteries
  • A rapid prediction method for cycle life of lithium-ion batteries

Examples

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no. 1 example

[0029] In the first embodiment of the present invention, a method for rapidly predicting the cycle life of a lithium-ion battery, such as figure 1 shown, including the following specific steps:

[0030] Step 1, carry out the cycle test of the first set number of times under the acceleration rate condition of the lithium battery to be tested, and record the following data after each test: the number of battery cycle tests and the corresponding actual capacity of the battery;

[0031] Step 2. Fitting is performed based on the data recorded in step 1 to obtain a first fitting relationship between the number of battery cycle tests and the actual capacity of the battery under accelerated conditions, and multiply the first fitting relationship by a fast compensation factor to obtain a fast prediction equation;

[0032] Optionally, the acquisition process of the fast compensation factor includes:

[0033] In step A1, the qualified lithium battery of the same type as the lithium bat...

no. 2 example

[0043] The second embodiment of the present invention, this embodiment is based on the above embodiments, combined with the attached Figure 2-4 An application example of the present invention is introduced.

[0044] Such as figure 2 As shown, a method for rapidly predicting the cycle life of a lithium-ion battery according to an embodiment of the present invention specifically includes the following steps:

[0045] S1: Conduct 500 cycle tests on a qualified lithium battery of the same type as the battery to be evaluated under the conditions of conventional rate (0.2C) and accelerated rate (≥0.5C), and record the number of battery cycles and its corresponding cycle capacity. The number of cycles in this embodiment is the number of cycle tests in the previous embodiments, and the cycle capacity is the actual capacity of the battery in the previous embodiments.

[0046] S2: Fitting the number of cycles of the 500-cycle test and its corresponding cycle capacity to obtain a fit...

no. 3 example

[0056] In the third embodiment of the present invention, the flow of the lithium-ion battery cycle life rapid prediction method of this embodiment is the same as that of the first and second embodiments, the difference is that, in terms of engineering implementation, this embodiment can add the necessary general hardware platform by means of software Of course, it can also be implemented by hardware, but in many cases the former is a better implementation. Based on this understanding, the method of the present invention can be embodied in the form of computer software products, which are stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and include several instructions to make a The station device executes the method described in the embodiment of the present invention.

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Abstract

The present invention proposes a method for rapidly predicting the cycle life of a lithium-ion battery, comprising the following steps: placing the battery to be evaluated in the cycle to be evaluated for 500 cycles under the conditions of conventional rate (0.2C) and accelerated rate (≥0.5C) Cycle test; fit the equation and calculate the compensation factor; test the battery for the first 100 cycles under the condition of acceleration rate (≥0.5C), multiply the fitting equation by the compensation factor k to obtain the fast prediction equation; substitute the number of short-term cycles 100 into the fast Prediction Equation Solving. The method is simple and accurate, with little deviation (<1%) from the actual test results, without the need for sophisticated test equipment and complex theoretical calculations, and can quickly predict the battery cycle life after a short-term cycle test, greatly reducing test costs and test time .

Description

technical field [0001] The invention relates to the technical field of lithium-ion battery cycle life testing, in particular to a method for rapidly predicting the cycle life of lithium-ion batteries. Background technique [0002] Lithium-ion batteries are widely used in the fields of mobile phones, notebook computers, digital audio and video products and other general consumer electronics products as well as electric vehicles, energy storage, drones, Aerospace and other new technology fields. [0003] An important index to evaluate the performance index of lithium-ion batteries is the cycle life. Various standards require that after 500 cycles according to the conventional rate (0.2C, C is the current capacity), the battery capacity should not be lower than 80% of the rated capacity, but to complete 500 tests, take a 1000mAh battery as an example, at least 7 batteries are required Months, time-consuming, and high testing costs have seriously hindered the further developme...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01R31/367G01R31/385G01R31/392G06Q10/04G06F30/20G06F119/04
CPCG01R31/367G01R31/385G01R31/392G06Q10/04G06F30/333G06F2119/04G06F30/20
Inventor 曹锦珠王宝友赵波谷家栋
Owner CHINA ELECTRONICS STANDARDIZATION INST