Secondary Battery Control Using Electrode Deterioration Bias
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Solution Overview
Problem
Existing secondary battery control systems fail to adaptively adjust charging/discharging operation conditions based on the relative deterioration degree of positive and negative electrodes, leading to inefficient battery management and reduced battery life.
Innovation Solution
An apparatus and method that utilize a sensor unit to measure voltage, current, and temperature, and a control unit to determine the State Of Charge (SOC) and electrochemical reaction resistance, identifying the deterioration-biased electrode and adjusting operation conditions such as charging cutoff voltage, C-rate, and rest time to mitigate electrode degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the charging/discharging operation condition is uniformly adjusted according to the overall deterioration degree of the secondary battery, then the battery management is simplified, but the control precision and effectiveness for specific deteriorated electrodes are reduced
Solution Approach 1:
The patent divides the battery deterioration assessment into separate evaluations for positive and negative electrodes. The determination unit calculates deterioration degrees for each electrode independently using their respective characteristics (voltage, capacity, resistance), then identifies which electrode has the greater deterioration degree. This segmentation enables precise targeting of the specific deteriorated electrode rather than treating the battery as a uniform whole.
2Duration of action of stationary object
If the charging cutoff voltage and C-rate are reduced to mitigate electrode degradation, then the battery life is extended, but the charging speed and power output are reduced
Solution Approach 1:
The patent implements dynamic adjustment of charging parameters based on real-time identification of the deteriorated electrode. The operation condition adjustment unit modifies charging cutoff voltage, C-rate, and other parameters adaptively according to which electrode (positive or negative) has the greater deterioration degree. This dynamic approach allows the system to optimize between battery life extension and charging speed by applying appropriate constraints only when and where necessary, rather than using fixed reduced parameters.
3Reliability
If the charging operation is focused on reducing charging cutoff voltage and C-rate at the end of charging section when positive electrode is more degraded, then the positive electrode structural damage is reduced, but the overall charging efficiency is reduced
Solution Approach 1:
The patent applies local quality control by identifying which specific electrode has the greater deterioration degree and applying targeted charging adjustments for that electrode. When the positive electrode is identified as more degraded, the system specifically adjusts charging parameters to protect the positive electrode during the end-of-charging section where structural damage is most likely. This localized approach ensures protective measures are applied only where needed rather than uniformly across all charging conditions.
4Reliability
If the rest time before charging is increased and C-rate is reduced in charging section where precipitation of working ions is expected when negative electrode is more degraded, then the working ion precipitation is prevented, but the charging time and cycle duration are increased
Solution Approach 1:
The patent applies preliminary action by implementing rest periods before charging when the negative electrode is identified as more degraded. The determination unit detects the negative electrode deterioration, and the operation condition adjustment unit proactively increases rest time and reduces C-rate in charging sections where working ion precipitation is expected. This preliminary protective action prevents deterioration before it occurs, rather than reacting after damage has been done, thereby maintaining battery reliability while minimizing time loss.
Data Source
AI summary
Disclosed is an apparatus and method for controlling an operation of a secondary battery using a relative deterioration degree of an electrode. The method includes determining a SOC of the secondary battery whenever a pulse current flows through the secondary battery; determining an electrochemical reaction resistance from a voltage change amount measured during a preset initial time in each pulse current section and determining a lithium ion diffusion resistance from a voltage change amount measured during a remaining time except for the initial time; determining a deterioration-biased electrode by comparing a deterioration diagnosing resistance ratio, which is a relative ratio of the lithium ion diffusion resistance to the electrochemical reaction resistance, with a preset reference deterioration diagnosing resistance ratio; and adaptively adjusting an operation condition of a next charging/discharging cycle according to the type of the deterioration-biased electrode.