Traction Battery Charging Control to Prevent Lithium Plating
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Solution Overview
Problem
Existing traction battery charging methods can lead to lithium precipitation and heating, posing safety risks such as fire and explosion, due to continuous charging, which affects the safety and longevity of the batteries.
Innovation Solution
A method and battery management system (BMS) that control the traction battery to discharge or temporarily stop charging based on preset parameter gap values, adjusting the frequency of discharging or stopping charge according to the state of charge (SOC) and open-circuit voltage (OCV), thereby preventing lithium precipitation and heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If continuous charging is applied to traction battery, then charging efficiency is improved, but lithium precipitation and heating occur causing safety risks
Solution Approach 1:
The patent implements periodic charging and discharging cycles instead of continuous charging. The control unit alternates between charging mode and discharging mode based on preset time intervals or parameter thresholds, preventing continuous charging that causes lithium precipitation and overheating while maintaining acceptable charging efficiency through optimized cycle patterns
Solution Approach 2:
The patent dynamically adjusts charging parameters including current, voltage, and time intervals based on real-time battery state monitoring. The control unit modifies charging intensity and duration according to battery temperature, charge level, and historical data, creating an adaptive charging process that prevents safety issues while maximizing charging efficiency
2Productivity
If charging frequency is increased to reduce charge duration, then productivity is improved, but lithium precipitation risk increases
Solution Approach 1:
The patent incorporates periodic rest intervals within the charging process where charging is temporarily suspended. These periodic pauses allow lithium ions to redistribute evenly in the electrolyte, preventing concentration gradients that lead to precipitation on electrode surfaces, while the overall charging frequency remains high enough to maintain acceptable charge duration
Solution Approach 2:
The system performs preliminary monitoring of battery parameters such as temperature, voltage, and charge level to predict conditions that may lead to lithium precipitation. Before precipitation can occur, the control unit preemptively adjusts charging parameters or introduces rest periods to counteract the developing harmful conditions
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 ensures the safety performance of traction batteries by preventing lithium precipitation and heating, reducing the risk of catastrophic events like fire or explosion, while also extending the battery's life and charge duration.
Implementation Method 1
avoid heating, lithium ion accumulation, etc. caused by continuous charging of the traction battery
Implementation Method 2
preventing lithium precipitation and heating
Data Source
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AI summary
Embodiments of the present application provide a method for charging a traction battery and a battery management system, which can effectively ensure the safety performance of the battery. The method includes: obtaining a battery parameter of the traction battery, the battery parameter comprising a state of charge SOC and/or an open-circuit voltage OCV; and during a charging process of the traction battery, controlling the traction battery to discharge or stop being charged when the battery parameter of the traction battery changes by a parameter gap value, where when the battery parameter of the traction battery is in a first parameter interval, the parameter gap value is a first preset parameter gap value; and when the battery parameter of the traction battery is in a second parameter interval, the parameter gap value is a second preset parameter gap value, where 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 that in the second parameter interval.