Battery Fast Charging With Interleaved CV Stages for Heat Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fast charging techniques for batteries, such as CC-CV-CC-CV, reduce battery cycle life due to excessive temperature rise during charging, which limits the number of charge-discharge cycles before capacity degradation occurs.
Innovation Solution
Implementing a charging method that interleaves constant voltage (CV) stages within constant current (CC) stages to mitigate temperature rise, and using a temperature control loop to regulate the charging current, ensuring it stays within safe limits to prevent excessive heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional fast charging techniques (CC-CV-CC-CV) are used to reduce charging time, then charging speed is improved, but battery temperature rises excessively causing cycle life degradation
Solution Approach 1:
The patent implements periodic interleaving of constant voltage (CV) charging stages between constant current (CC) charging stages. This periodic action allows the battery to rest and cool down temporarily during charging, preventing excessive temperature accumulation while maintaining overall fast charging performance. The CV stages act as periodic interruptions that reduce thermal stress on the battery.
Solution Approach 2:
The patent employs a temperature control loop that continuously monitors battery temperature and provides feedback to adjust charging current. When temperature approaches predefined thresholds, the system automatically reduces charging current or inserts CV stages to prevent overheating. This closed-loop feedback mechanism dynamically balances charging speed with temperature management.
2Loss of time
If high constant current is applied to achieve fast charging, then charging time is reduced, but battery capacity degradation accelerates
Solution Approach 1:
The patent segments the charging process into multiple alternating CC and CV stages rather than using continuous high current. By dividing the charging timeline into discrete phases with different current profiles, the system achieves fast charging overall while preventing sustained high current exposure that causes capacity degradation. Each CC stage is followed by a CV stage that allows partial recovery.
Solution Approach 2:
The interleaved CC-CV charging pattern creates periodic variations in current application. The CV stages serve as periodic low-stress intervals that allow the battery chemistry to stabilize and reduce cumulative degradation effects, while the CC stages provide the high-speed charging needed to minimize total charging time.
3Productivity
If multiple CC-CV cycles are used to charge the battery, then charging speed improves, but the number of charge-discharge cycles before capacity degradation decreases
Solution Approach 1:
The temperature control loop with predefined thresholds provides feedback-based modulation of charging parameters. When temperature approaches critical levels during CC-CV cycling, the system automatically inserts additional CV stages or reduces current, dynamically adjusting the charging profile to protect battery lifespan while maintaining efficient charging when conditions permit.
Solution Approach 2:
The patent dynamically changes charging parameters (current magnitude, stage duration, number of interleaved CV stages) based on real-time battery conditions such as temperature and state of charge. This adaptive parameter adjustment optimizes the balance between charging efficiency and battery durability, modifying the CC-CV cycle characteristics to prevent degradation while maintaining fast charging performance.
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 approach reduces battery temperature rise while maintaining reasonable charging speed, thereby extending battery cycle life and ensuring efficient charging without significant increases in overall charge time.
Implementation Method 1
re-chargeable batteries... charging a battery... discharge cycles before a battery's capacity degrades
Implementation Method 2
excessive temperature rise during charging... mitigate temperature rise... prevent excessive heating
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
Some examples provide battery charging techniques that allow for reasonably fast charging while reducing charging temperature. In some examples, a target temperature limit is actively maintained through a control loop. In some examples, CC charge phases are interleaved with CV stages.