Electrochemical Energy Storage Aging State Determination

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Solution Overview

Problem

Existing methods for determining the aging state of electrochemical energy storage devices are inconsistent and lack precision, leading to varying results across different manufacturers and workshops.

Innovation Solution

A procedure that involves measuring the voltage of an electrochemical energy storage, comparing it to a target voltage, and determining the aging state based on the voltage gradient during controlled charging and discharging cycles at fixed temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If different manufacturers use different SOH algorithms and procedures, then each manufacturer can optimize for their specific battery model, but measurement precision and comparability across different devices deteriorate

Engineering Contradiction:
Improvemanufacturer-specific optimizationVSAvoidaging state determination precision
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent changes the parameters of the test procedure to achieve both manufacturer-specific optimization and cross-device comparability. By standardizing key parameters such as discharge rate (0.1C to 0.5C), temperature conditions (15°C to 35°C), and evaluation metrics (voltage gradient, capacity retention), the method enables precise and comparable aging state determination across different battery models while still allowing manufacturers to optimize within this standardized framework.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If dynamic or stationary states are used for SOH determination during driving cycles, then real-world operating conditions are reflected, but measurement precision deteriorates due to varying conditions

Engineering Contradiction:
Improvereal-world condition assessmentVSAvoidaging state determination precision
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by performing a standardized conditioning procedure before the actual SOH measurement. The battery is charged to a defined state of charge (e.g., 80-100%), then rested for a specified period to reach thermal and electrochemical equilibrium. This preliminary preparation ensures that subsequent measurements are taken from a known, consistent starting point, eliminating the variability introduced by dynamic operating conditions while still reflecting real-world performance.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If high discharge rates are used for testing, then test duration is reduced, but manufacturing precision and reliability of aging state determination deteriorate

Engineering Contradiction:
Improvetest speedVSAvoidvoltage gradient measurement precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies partial action by using a moderate discharge rate (0.1C to 0.5C) rather than maximum available discharge rate. This partial discharge approach is sufficient to elicit measurable voltage gradients that reflect aging effects, while avoiding the excessive currents that would introduce measurement errors, thermal effects, and safety concerns. The chosen discharge rate provides an optimal balance between test duration and measurement precision.

Inventive Principle:
Principle #16Partial or excessive action

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 method provides a high-precision determination of the aging state, enabling reliable service life assessment and facilitating comparability across different energy storage devices, which is particularly beneficial for second-life applications.

Implementation Method 1

electrochemical energy storage device; charge or discharge a battery

Methodology Applied
Scientific EffectElectrochemical reactions: Redox Reactions

Implementation Method 2

Detecting the voltage value during discharging and determining a voltage gradient of the detected voltage value

Methodology Applied
Scientific EffectElectrochemical potential: Nernst Effect

Data Source

PatentEP4111220B1Method for determining a state of health of at least one electrochemical energy storage device
Publication Date: 2025.04.09 ROBERT BOSCH GMBH
  • EP4111220B1 patent drawingFigure 1
  • EP4111220B1 patent drawingFigure 2
  • EP4111220B1 patent drawingFigure 3~4

AI summary

Method for determining a state of health of at least one electrochemical energy storage device.