Battery Cell Internal Short Detection via Efficiency and Temperature Drift
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Solution Overview
Problem
Existing lithium secondary batteries face challenges in diagnosing internal short circuits, which can lead to safety issues such as thermal runaway, particularly in large-capacity systems like electric vehicles and energy storage systems, due to factors like deformation, foreign matter, or lithium dendrite formation.
Innovation Solution
A method and apparatus that measure charge efficiency and temperature changes over multiple charge/discharge cycles to diagnose internal short circuits by setting threshold values for efficiency and temperature deviations, using a controller to analyze these changes and determine if an internal short circuit is present.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If internal short circuit diagnosis is performed using traditional methods, then safety issues such as thermal runaway may occur, but early detection of internal short circuits is difficult
Solution Approach 1:
The patent performs preliminary diagnosis actions by measuring charge efficiency and temperature changes during normal charge/discharge cycles before thermal runaway occurs. The system calculates deviations from reference values and counts violations of threshold conditions to detect internal short circuits in advance, enabling preemptive safety measures.
Solution Approach 2:
The patent implements feedback mechanisms by continuously monitoring charge efficiency and temperature changes, comparing measured values against reference values, and adjusting diagnosis based on the number of violations. This feedback loop enables dynamic detection and diagnosis of internal short circuit conditions.
2Measurement precision
If charge efficiency and temperature are monitored continuously, then internal short circuits can be detected early, but measurement and data processing requirements increase
Solution Approach 1:
The patent uses the battery's own charge/discharge process to generate diagnostic data. The normal operational parameters (charge efficiency and temperature) serve dual purposes: maintaining battery function and providing diagnostic information, eliminating the need for separate complex testing equipment.
Solution Approach 2:
The patent monitors changes in operational parameters (charge efficiency and temperature) rather than absolute values. By calculating deviations from reference values and threshold violations, the system transforms complex continuous measurements into simplified diagnostic indicators.
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
Enables preemptive diagnosis of internal short circuits, preventing potential thermal runaway by identifying abnormal charge efficiency and temperature increases, thereby ensuring safety in lithium secondary batteries.
Implementation Method 1
The charging and discharging of the battery cell may be performed by providing electrolyte in the case of the battery cell and causing an electrochemical reaction between the anode, the cathode, and electrolyte
Implementation Method 2
Lithium ions move between the anode and the cathode through the electrolyte, thereby allowing for charging and discharging of the battery to occur
Data Source
AI summary
A method and apparatus for diagnosing an internal short circuit in a battery are provided. The method includes measuring charge efficiency of a battery cell in each of a plurality of charge/discharge cycles; measuring temperature of the battery cell in each of the charge/discharge cycles; calculating a change in the charge efficiency in a charge/discharge cycle from a previous charge/discharge cycle in each of the charge/discharge cycles; calculating change in the temperature in the charge/discharge cycle from the previous charge/discharge cycle in each of the charge/discharge cycles; and diagnosing an internal short circuit of the battery cell based on the change in the charge efficiency and the change in the temperature.