Traction Battery Charging Control for Lithium Plating Prevention
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Solution Overview
Problem
Continuous charging of traction batteries can lead to lithium precipitation and heating, posing safety risks such as battery fires or explosions, which compromises the safety performance and lifespan of the batteries.
Innovation Solution
A method and battery management system (BMS) that control the charging process by determining parameter gap values based on the state of charge (SOC) and open-circuit voltage (OCV) to intermittently discharge or stop charging the battery, thereby preventing excessive heating and lithium accumulation, with parameter gap values ranging from 3% to 95% to balance charge and discharge cycles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If continuous charging is applied to the traction battery, then charging efficiency is improved, but safety performance deteriorates due to heating and lithium precipitation
Solution Approach 1:
The patent implements periodic charging and discharging cycles by controlling the battery management system to switch between charging and discharging modes based on real-time monitoring of battery parameters (temperature, voltage, current). This periodic action prevents continuous charging from causing lithium precipitation and overheating, thereby resolving the contradiction between charging efficiency and safety performance
Solution Approach 2:
The patent employs a feedback mechanism where the battery management system continuously monitors battery parameters including temperature, voltage, and current during charging. Based on this feedback, the system dynamically adjusts charging parameters or initiates discharging when safety thresholds are approached, thus maintaining both high charging efficiency and safety performance
2Reliability
If the parameter gap value is small (high discharge frequency), then safety performance is improved by preventing lithium precipitation, but charge duration increases
Solution Approach 1:
The patent makes the parameter gap value dynamic rather than fixed. The battery management system adjusts the parameter gap value based on real-time battery state (temperature, SOC level, charging rate). When battery safety risks are high, the system reduces the parameter gap value to increase discharge frequency; when risks are low, it increases the parameter gap value to reduce discharge frequency and minimize charge duration
Solution Approach 2:
The patent changes the parameter gap value as a controllable parameter to optimize the balance between safety and charging speed. By dynamically adjusting this parameter based on battery condition, the system achieves adaptive control that prevents lithium precipitation while minimizing impact on overall charge duration
3Loss of time
If the parameter gap value is large (low discharge frequency), then charge duration is reduced, but safety performance deteriorates due to increased lithium precipitation risk
Solution Approach 1:
The system dynamically adjusts the parameter gap value based on real-time battery monitoring. When the battery reaches states prone to lithium precipitation (high SOC, elevated temperature), the system automatically reduces the parameter gap value to increase discharge frequency, thus maintaining safety performance while minimizing charge duration extension
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively mitigates safety hazards and extends the battery's lifespan by preventing lithium precipitation and overheating, ensuring the safety and performance of traction batteries during charging.
Implementation Method 1
lithium precipitation is more likely to occur
Implementation Method 2
avoid heating, lithium ion accumulation, etc. caused by continuous charging
Data Source
AI summary
A method for charging a traction battery includes obtaining a battery parameter of the traction battery that includes a state of charge and/or an open-circuit voltage, and, during a charging process of the traction battery, controlling the traction battery to discharge or stop being charged in response to the battery parameter changing by a parameter gap value. The parameter gap value is a first preset parameter gap value in a scenario in which the battery parameter of the traction battery is in a first parameter interval, and is a second preset parameter gap value in a scenario in which the battery parameter of the traction battery is in a second parameter interval. The first preset parameter gap value is greater than the second preset parameter gap value, and the battery parameter in the first parameter interval is less than the battery parameter in the second parameter interval.