Lithium-Sulfur Battery Capacity Estimation Using Pulse Voltage Drop
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for determining the remaining capacity of lithium-sulfur batteries are complex and inaccurate, especially when the capacity is below 70%, due to the non-proportional relationship between operating voltage and capacity.
Innovation Solution
A method involving measuring initial and additional voltage drops (dV1 and dV3) using a high output pulse to calculate the X value, which accurately determines the remaining capacity through equations, especially below 70% capacity, and combining this with open-circuit voltage for capacities above 70%.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional methods (complex modeling, optical monitoring) are used to determine remaining capacity, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent extracts only the essential voltage measurement data at specific SOC points (0%, 30%, 70%, 100%) to create a simplified lookup table, eliminating the need for complex modeling or optical monitoring systems while maintaining sufficient measurement precision for battery management
Solution Approach 2:
The patent changes the measurement approach from continuous monitoring to discrete point measurement at specific SOC thresholds, transforming the parameter measurement strategy to reduce complexity while preserving essential information for remaining capacity determination
2Device complexity
If voltage measurement only is used to determine remaining capacity, then device complexity is reduced, but measurement precision deteriorates when capacity is below 70%
Solution Approach 1:
The patent performs preliminary voltage measurements at specific SOC points (0%, 30%, 70%, 100%) during battery cycling to build a reference lookup table in advance, enabling accurate remaining capacity determination through simple comparison without requiring complex real-time analysis
Solution Approach 2:
The patent replaces the continuous voltage measurement approach with a discrete lookup table method, substituting the mechanical/continuous measurement system with a data-driven discrete system that achieves higher precision with simpler implementation
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
Provides a simple and accurate method to determine lithium-sulfur battery capacity, enhancing precision and expanding the battery's application range.
Implementation Method 1
measuring an initial voltage drop value dV1 at any one point in a range of 0.01 to 0.3 sec after the application of the constant current; measuring a late voltage drop value dV2 at any one point in a range of 0.5 sec to 20 sec after the application of the constant current
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The present invention provides a method for determining the remaining capacity of a lithium-sulfur battery using a voltage drop value obtained by applying a constant current in an open-circuit state and a battery pack implementing the method.