Battery Cell Impedance Monitoring for Safe Operating Limits

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional battery management systems rely on external measurements like surface temperature and voltage, which lack direct insight into internal cell conditions, leading to inaccurate safety assessments, failure to detect certain failure modes, and limited adaptability, compromising safety and efficiency.

Innovation Solution

Utilizing electrochemical impedance spectroscopy (EIS) to measure complex impedance across frequencies, establishing safe operating area (SOA) limits for each cell, and comparing live measurements to these limits for real-time detection of unsafe conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional battery management systems use external measurements like surface temperature and voltage, then the system complexity is low, but the measurement precision of internal cell conditions is insufficient

Engineering Contradiction:

Improveinternal cell conditions measurementVSAvoidmeasurement system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces complex impedance as an intermediary parameter that can be measured externally but reflects internal cell conditions. By using impedance spectroscopy, the system indirectly probes internal states (electrolyte conductivity, electrode integrity, separator condition) without direct internal sensors, thus improving measurement precision while avoiding excessive system complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct physical/mechanical sensing of internal cell conditions with electrical impedance measurement. Instead of using complex internal sensors or invasive probes, the system uses electrical signals to characterize internal cell state through impedance spectra, substituting a simpler electrical measurement approach for complex mechanical/physical sensing.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If conventional battery management systems rely on limited external parameters, then the device complexity is low, but the adaptability to different failure modes is poor

Engineering Contradiction:

Improvedetection of failure modesVSAvoidbattery management system complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent transitions from monitoring a single dimension (voltage or temperature) to measuring complex impedance across multiple frequencies. This dimensional expansion provides a spectrum of information that can distinguish between different failure modes (internal shorts, electrode degradation, electrolyte depletion) that would be indistinguishable using conventional single-parameter monitoring.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent changes the measurement parameter from simple voltage/temperature to complex impedance with frequency dependence. By analyzing how impedance varies with frequency, the system can identify different failure mechanisms based on their characteristic impedance signatures, greatly enhancing adaptability to various failure modes.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If conventional battery management systems use simple voltage and temperature monitoring, then the ease of operation is high, but the reliability of safety assessment is compromised

Engineering Contradiction:

Improvesafety assessment reliabilityVSAvoidbattery management operation

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent implements a feedback mechanism where complex impedance measurements continuously inform the battery management system about internal cell health. The system compares measured impedance spectra against reference data or thresholds to detect unsafe conditions, providing reliable safety feedback that triggers appropriate responses (charging/discharging control, warnings) while maintaining operational simplicity through automated decision logic.

Inventive Principle:

Principle #23Feedback

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 direct, real-time assessment of battery health and safety, improving reliability, safety, and efficiency by detecting internal anomalies and enabling adaptive management.

Implementation Method 1

Electrochemical impedance spectroscopy (EIS) in battery operation. EIS can measure the complex impedance of one or more cells over a range of frequencies

Methodology Applied

Scientific EffectElectrochemical impedance spectroscopy: Electrical Impedance Tomography

Data Source

PatentUS20260023129A1Battery operation

Publication Date: 2026.01.22 ANALOG DEVICES INT UNLTD CO

AI summary

Examples of the computer-implemented technology disclosed herein establish limits for at least one component of complex impedance for each of a plurality of cells of a battery of a battery type at each of at least one frequency, thereby establishing a safe operating area for the battery within the limits. Such examples measure the at least one component of complex impedance of each of at least one cell of a given battery of the battery type. Such examples compare the measured at least one component of complex impedance to the limits. Such examples manage operation of the given battery based on the comparison.