Battery Cell Venting Detection Using dQ/dV and SoH Analysis
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Solution Overview
Problem
Existing technologies fail to accurately determine venting in lithium-ion batteries, which can lead to cell performance deterioration and potential ignition due to electrolyte leakage.
Innovation Solution
A battery state management apparatus and method that computes capacity/voltage differential values and gradients to detect venting in battery cells based on state of health (SoH), using dynamic time warping to analyze changes in capacity/voltage differentials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional battery monitoring methods are used, then the system is simple to operate, but venting detection precision is insufficient
Solution Approach 1:
The patent segments the venting detection process into multiple independent calculation stages: (1) calculating dQ/dV values from capacity and voltage data, (2) computing gradients from sequential dQ/dV values, (3) comparing gradients against threshold values, and (4) determining venting occurrence. This segmentation allows complex detection logic to be implemented through systematic computational steps rather than requiring complex hardware modifications.
Solution Approach 2:
The patent introduces intermediate computational parameters (dQ/dV values and gradients) as mediators between raw battery measurements (capacity, voltage) and the final venting determination. These intermediate values transform raw electrical measurements into meaningful indicators of venting conditions, enabling accurate detection without direct physical intervention in the battery system.
2Reliability
If early venting detection is implemented, then cell performance deterioration is prevented, but false alarms may increase
Solution Approach 1:
The patent performs preliminary calculations of dQ/dV values and gradients during normal battery operation, establishing baseline patterns before venting actually occurs. By computing these parameters continuously and comparing against predetermined threshold values, the system identifies early signs of venting (gradual gradient changes) before they progress to actual venting events, enabling preventive action while maintaining detection accuracy.
Solution Approach 2:
The patent implements a feedback mechanism where gradient values are continuously calculated from sequential dQ/dV measurements and compared against threshold values to determine venting occurrence. This feedback loop allows the system to adapt to changing battery conditions while maintaining consistent detection criteria, reducing false alarms by distinguishing between normal variations and actual venting patterns through systematic comparison of sequential measurements.
Data Source
AI summary
A battery state management apparatus according to an embodiment disclosed herein includes a processor and memory having programmed thereon instructions that, when executed, are configured to cause the processor to receive a measured capacity, a voltage, and a state of health (SoH) of a battery cell corresponding to a charge/discharge cycle, and compute a capacity/voltage differential value (dQ/dV) corresponding to the charge/discharge cycle of the battery cell based on the capacity and the voltage, and determine a state of the battery cell based on the capacity/voltage differential value corresponding to the charge/discharge cycle and the SoH of the battery cell.