Secondary Battery SOC Segmentation to Prevent Deterioration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium ion secondary batteries, particularly those with manganese lithium oxide as the positive electrode material, experience rapid performance deterioration when stored at a specific State of Charge (SOC) between the maximum and minimum limits, leading to shortened product life cycles.
Innovation Solution
A secondary battery system and operating method that detect the SOC and charge or discharge the battery within predefined regions set by first and second thresholds, preventing the battery from entering the deteriorating SOC range, thereby maintaining performance and extending life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the lithium ion secondary battery is stored at a particular SOC (between maximum and minimum SOC), then the battery is ready for use at any charge level, but the battery performance quickly deteriorates
Solution Approach 1:
The patent divides the SOC range into multiple regions (first region: minimum SOC to first threshold, second region: second threshold to maximum SOC, third region: between thresholds) and defines different control strategies for each region. This segmentation prevents the battery from being stored in the harmful intermediate SOC range while allowing flexible operation in the safe regions.
Solution Approach 2:
The patent changes the operational parameters by setting specific threshold values for SOC and adjusting charging/discharging control based on the current SOC region. By dynamically changing control parameters (charging current, discharging current, or stopping operations) based on SOC region, the system avoids the deteriorating SOC range while maintaining operational flexibility.
2Reliability
If the battery is stored in the fully charged state (maximum SOC), then the battery maintains stable performance, but the battery cannot be used for applications requiring intermediate charge levels
Solution Approach 1:
The patent segments the SOC range into multiple regions and allows the battery to operate in the first region (minimum SOC to first threshold) and second region (second threshold to maximum SOC). This enables the battery to be used at intermediate charge levels while avoiding the harmful third region, thus maintaining both stability and adaptability.
Solution Approach 2:
The patent implements dynamic control strategies that adjust charging and discharging operations based on the current SOC region. The control device can switch between different operating modes (charging, discharging, or stopping) depending on which region the battery is in, providing adaptability for different applications while preventing storage in the deteriorating SOC range.
3Reliability
If the battery undergoes frequent charging and discharging cycles to avoid intermediate SOC storage, then the battery performance is maintained, but the product life cycle is shortened
Solution Approach 1:
The patent divides the SOC range into safe operating regions (first and second regions) and a harmful region (third region). By controlling the battery to operate only in the safe regions and avoiding the harmful intermediate region, the system maintains battery performance stability without requiring excessive charging/discharging cycles, thus preserving the product life cycle.
Solution Approach 2:
The control device continuously monitors the SOC and provides feedback control to adjust charging and discharging operations. When the SOC approaches the threshold values that define the boundary of the harmful region, the control device adjusts operations to prevent entry into this region, maintaining performance stability while minimizing unnecessary cycles.
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
The solution effectively prevents battery performance deterioration during storage by segregating the SOC range into regions, ensuring continuous operation and reducing the risk of charging or discharging interruptions, thus prolonging the battery's lifespan.
Implementation Method 1
a control device that, while detecting the SOC of the secondary battery, charges the secondary battery with electric power from an electric power source and supplies the electric power discharged from the secondary battery to a load
Data Source
AI summary
A secondary battery has a progressively deteriorating SOC in which battery performance deteriorates when the secondary battery is stored, and is charged and discharged by a control device. An information processing device stores a preset first threshold smaller than the progressively deteriorating SOC of the secondary battery and a preset second threshold greater than the progressively deteriorating SOC, and separates the range from the minimum SOC to the maximum SOC of the secondary battery into, at least, two regions by setting the section from the first threshold to the second threshold as a boundary to thereby cause the control device to charge or discharge the secondary battery within any of the above regions.