Power Battery Life Prediction Model Using Temperature and Discharge Rate
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Solution Overview
Problem
The complex process of predicting the service life of retired power batteries in new energy vehicles is inefficient due to the need for extensive testing, which affects production efficiency and accuracy, as it is influenced by cycle working conditions and environmental changes such as temperature and discharge systems.
Innovation Solution
A method is developed to establish a three-dimensional prediction model for the remaining life of power batteries by conducting charge and discharge cycles at various rates and temperatures, calculating capacity loss rates, and creating a life attenuation curve, which is then used to fit a service life prediction model considering factors like temperature, discharge rate, and activation energy, allowing for quick estimation of remaining life using a product factor of discharge rate and temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a large number of experiments are carried out on each retired power battery to determine the remaining life, then the prediction accuracy is improved, but the production efficiency is greatly affected
Solution Approach 1:
The patent establishes a service life prediction model in advance using comprehensive experimental data from multiple batteries under different conditions. This pre-established model can then be used to quickly predict the remaining life of retired batteries without requiring extensive new testing, thus resolving the contradiction between prediction accuracy and production efficiency
Solution Approach 2:
The patent creates a virtual three-dimensional prediction model that replicates the complex relationships between temperature, discharge rate, and cycle life. This digital model serves as a copy of the physical testing process, allowing rapid predictions without repeating expensive and time-consuming physical experiments on each retired battery
2Measurement precision
If comprehensive life tests including cycle life test and calendar life test are conducted, then the service life prediction accuracy is improved, but the testing complexity and time consumption increase
Solution Approach 1:
The patent merges cycle life test data and calendar life test data into a unified three-dimensional prediction model that incorporates both degradation mechanisms. By combining these different test types into a single integrated model, the patent achieves comprehensive service life prediction without requiring separate complex testing procedures for each type
Solution Approach 2:
The patent transforms the complex multi-parameter testing requirements into a simplified prediction framework by changing the parameters to temperature, discharge rate, and cycle life in a three-dimensional space. This parameter transformation allows the model to capture the essential degradation behavior without requiring all original test conditions to be replicated
Data Source
AI summary
This invention discloses a method for predicting the service life of a retired power battery. The service life of a retired power battery may be predicted by its power battery life attenuation curve. The power battery life attenuation curve is obtained by establishing a power battery life model and a charge and discharge characteristic curve of the power battery by utilizing the temperature T, the discharge rate C and the discharge depth DOD in the charging and discharging process of the power battery. This invention establishes a three-dimensional relation graph with a cycle life with respect to the capacity loss rate and the functional relationship ω=ƒ(T,C) by using the power battery life attenuation curve. The three-dimensional relation graph is applied to the same type of battery. And the attenuation of the battery in the full life cycle may be predicted.