Dynamic Battery Charging Rate Control to Prevent Li-Plating
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Solution Overview
Problem
Conventional battery charging methods, such as constant current and constant voltage methods, often lead to excessive charging rates that degrade battery performance, cause Li-plating, and reduce battery life, while fast charging is essential for electric vehicles and other applications.
Innovation Solution
A battery charging method that starts with an initial charging rate higher than 1 C and reduces it stepwise to prevent the negative electrode potential from dropping below 0V, using a protocol derived from measuring the negative electrode potential as a function of State of Charge at different charging rates, thereby controlling the charging current to prevent Li-plating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If constant current charging method is used with high charging current to achieve fast charging, then charging speed is improved, but battery life is reduced and Li-plating occurs
Solution Approach 1:
The patent applies dynamic charging rate adjustment by transitioning from constant current charging to variable current charging based on state of charge. The charging rate is dynamically reduced when the negative electrode potential approaches 0V to prevent Li-plating, while maintaining high charging rates when safe. This dynamic adaptation resolves the contradiction by allowing fast charging when conditions permit while protecting battery life when risks arise.
Solution Approach 2:
The patent implements feedback control by continuously monitoring the negative electrode potential during charging. When the potential approaches the critical 0V threshold, the system automatically reduces the charging current to prevent Li-plating. This feedback mechanism enables the charger to adapt to real-time battery conditions, achieving both fast charging and battery protection.
2Loss of time
If constant current charging is used to charge batteries quickly, then charging time is reduced, but charging efficiency decreases and battery performance degrades
Solution Approach 1:
The patent uses dynamic charging rate adjustment to optimize the balance between charging speed and efficiency. By reducing current only when the negative electrode potential approaches 0V (typically at higher state of charge), the system maintains high charging efficiency during the majority of the charging process while still reducing overall charging time compared to conservative constant voltage methods.
3Speed
If high charging rate is applied to achieve fast charging, then charging speed is improved, but negative electrode potential drops to 0V or less causing Li-plating
Solution Approach 1:
The patent applies preliminary anti-action by proactively reducing the charging current before the negative electrode potential reaches the critical 0V threshold that causes Li-plating. Instead of waiting for Li-plating to occur and then correcting it, the system preemptively adjusts the charging rate based on predicted potential changes, preventing the harmful effect before it can manifest.
Solution Approach 2:
The system continuously monitors negative electrode potential and provides real-time feedback to adjust charging current. When the potential approaches 0V, the feedback loop automatically reduces current to maintain the potential above the Li-plating threshold, thereby preventing the harmful effect while maintaining optimal charging speed.
Data Source
AI summary
Provided are a method and an apparatus for rapidly charging a battery, such that a battery can be rapidly charged while having an extended lifetime. The method for charging a battery according to the present invention charges a battery by starting from an initial charging rate higher than 1 C, while stepwise decreasing the charging rate, such that a negative electrode potential of the battery does not drop to a level less than or equal to 0V. An occurrence of Li-plating of a negative electrode of the battery can be prevented by the criteria for preventing the negative electrode potential from dropping to a level less than or equal to 0V, thereby providing an effect of rapidly charging the battery while extending the lifetime of the battery.