Battery Electrochemical Modeling for Salt Precipitation Diagnosis
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Solution Overview
Problem
Existing battery management systems face challenges in accurately diagnosing battery abnormalities, particularly lithium plating and salt precipitation, which can reduce battery lifespan and cause internal short circuits, especially at low temperatures due to slowed lithium ion diffusion.
Innovation Solution
A method and apparatus using an electrochemical model based on a single particle model of a battery's cathode and anode to estimate internal lithium ion concentrations and diagnose salt precipitation by calculating the difference in lithium ion diffusion between the cathode and anode, and determining the potential of the electrolyte and anode to assess overpotential.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If lithium ion diffusion is slowed at low temperature, then battery operation continues, but salt precipitation occurs and battery lifespan is reduced
Solution Approach 1:
The system performs preliminary diagnosis of salt precipitation risk by calculating overpotential before it reaches critical levels. By continuously monitoring the difference between anode and electrolyte potentials using the electrochemical model, the system takes preventive action by controlling charge current before salt precipitation actually occurs, thereby preventing battery damage at low temperatures
Solution Approach 2:
The system implements feedback control by using the electrochemical model to calculate real-time overpotential and comparing it against threshold values. Based on this feedback, the battery management system adjusts charge/discharge current to maintain overpotential within safe limits, preventing salt precipitation while enabling low-temperature operation
2Power
If charge current is increased to improve battery performance, then power output increases, but lithium plating occurs and internal short circuits are caused
Solution Approach 1:
The system calculates the overpotential using the electrochemical model before lithium plating occurs. By determining the difference between anode potential and electrolyte potential in advance, the system establishes a safety threshold that prevents charge current from reaching levels that would cause lithium plating and subsequent internal short circuits
Solution Approach 2:
The electrochemical model acts as an intermediary between the battery management system and the physical battery. It translates electrical parameters into chemical state information (lithium ion concentration, overpotential), enabling the BMS to make informed decisions about charge current control to prevent harmful effects
3Device complexity
If traditional battery management methods are used, then system simplicity is maintained, but accurate diagnosis of salt precipitation and lithium plating is not achieved
Solution Approach 1:
Instead of adding complex physical sensors to directly measure internal battery states, the system creates a virtual copy of the battery's electrochemical behavior through mathematical modeling. The electrochemical model replicates the relationship between current, voltage, temperature, and lithium ion concentration, enabling accurate diagnosis of salt precipitation and lithium plating using only standard electrical measurements
Solution Approach 2:
The system replaces the need for complex physical measurement devices with an electrochemical model based on electrical and thermal measurements. By substituting direct physical sensing of lithium ion concentration with mathematical calculation based on voltage, current, and temperature data, the system achieves high diagnostic accuracy without significantly increasing hardware complexity
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 diagnoses salt precipitation and prevents rapid battery aging and internal short circuits by controlling current and voltage, thereby extending battery life.
Implementation Method 1
considering a difference in diffusion of lithium ions between the cathode and the anode of the battery
Implementation Method 2
estimate an internal state of the battery by using a difference between the internal lithium ion concentrations of the cathode and the anode
Implementation Method 3
calculating a value of an overpotential between the anode and the separator of the battery by using the potential of the electrolyte and the potential of the anode
Data Source
AI summary
A method of diagnosing battery abnormalities including acquiring at least one parameter of the battery, and determining, based on, salt precipitation of the battery by using an electrochemical model calculated based on a single particle model of a cathode and an anode of the battery, the electrochemical model comprising a model configured to calculate internal lithium ion concentrations of the cathode and the anode by considering a difference in diffusion of lithium ions between the cathode and the anode of the battery and to estimate an internal state of the battery by using a difference between the internal lithium ion concentrations of the cathode and the anode.