Secondary Battery Formation Aging Reset for Low-Voltage Screening
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Solution Overview
Problem
Existing methods for activating secondary batteries struggle to accurately detect low voltage defects due to similar voltage drop amounts between good and defective products, leading to difficulties in identifying and preventing failures, damage, or ignition.
Innovation Solution
A method involving pre-aging, primary charging, high temperature aging, and room temperature aging with a resetting process at the same charge rate as primary charging, which reduces voltage drop deviation and improves detection power by forming a stable SEI film and minimizing voltage drop in good products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional activation process is used, then activation is completed, but voltage drop deviation of good products is large making low voltage defect detection difficult
Solution Approach 1:
The patent applies preliminary action by performing a pre-aging step before the main activation process. The secondary battery is aged at room temperature for 0.5 to 72 hours before primary charging, which stabilizes the battery's initial state and reduces voltage drop deviation during subsequent activation, thereby improving low voltage defect detection accuracy.
Solution Approach 2:
The patent implements periodic action through multiple alternating aging and charging steps. The activation process includes room temperature aging, primary charging, high temperature aging, secondary charging, and final room temperature aging in a periodic sequence. This periodic treatment stabilizes the battery's voltage characteristics and reduces deviation, enhancing defect detection capability.
2Manufacturing precision
If room temperature aging is performed without resetting, then aging process is simple, but voltage drop amount and deviation of good products remain high
Solution Approach 1:
The patent segments the activation process into distinct phases: pre-aging, primary charging, high temperature aging, secondary charging, and final room temperature aging. Each segment serves a specific function in stabilizing voltage characteristics. The resetting step (secondary charging) divides the aging process to control voltage drop, reducing deviation while maintaining manageable process complexity.
Solution Approach 2:
The patent applies parameter changes by varying temperature conditions (room temperature and high temperature) and charging states (primary charging to 60-100% SOC and secondary charging to same SOC) throughout the activation process. These parameter changes stabilize the battery's voltage characteristics and reduce voltage drop deviation of good products.
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 method effectively reduces the voltage drop deviation in good products, enhancing the detection power of low voltage defects, thereby preventing defective batteries from being distributed or used, and preventing potential failures, damage, or ignition.
Implementation Method 1
a secondary battery including a positive electrode containing a positive electrode active material, a negative electrode containing a negative electrode active material, a separator interposed between the positive electrode and the negative electrode, and an electrolyte
Implementation Method 2
some of secondary batteries that have been manufactured have a phenomenon of exhibiting a voltage drop behavior over a self-discharge rate
Data Source
AI summary
The present invention comprises: a pre-aging step for aging, at room temperature, a secondary battery comprising a cathode including a cathode active material, an anode including an anode active material, a separator interposed between the cathode and the anode, and an electrolyte (S100); a first charging step for primarily charging the pre-aged secondary battery to an SOC of the secondary battery of 60% or higher (S200); a high-temperature aging step for aging the primarily charged secondary battery at a high temperature (S300); and a room-temperature aging step for aging the high-temperature aged secondary battery at room temperature (S400), wherein the room-temperature aging step comprises a resetting process for charging the secondary battery to the same SOC as in the first charging step.