Electrode Plate Pulse-Laser Cutting to Limit Sputter and Peel-Off
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Solution Overview
Problem
The manufacturing of electrode plates in secondary batteries often results in broken pieces of the electrode active material layer or fine metal pieces (sputter) falling off or peeling off, leading to potential internal short circuits due to reduced adhesive properties and sputter scattering during laser cutting.
Innovation Solution
A manufacturing method using pulse lasers for both the active material provided area and core exposed area, with specific pulse width and lap rate conditions to minimize melt contamination and sputter scattering, ensuring efficient and continuous cutting without significant efficiency loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a laser is used to cut the electrode plate, then the cutting efficiency is improved, but the electrode active material layer or fine metal pieces (sputter) easily fall off or peel off due to heat-induced melting and reduced adhesive properties
Solution Approach 1:
The patent applies periodic action by using pulse laser irradiation instead of continuous laser irradiation. The laser is irradiated in pulses with specific parameters (pulse width 10 ns to 1 ms, repetition frequency 1 Hz to 1 MHz) to cut the electrode plate while minimizing heat accumulation. This periodic irradiation allows the material to cool between pulses, preventing excessive melting that would cause the electrode active material layer to detach, thus maintaining both cutting efficiency and adhesive properties.
Solution Approach 2:
The patent applies parameter changes by optimizing multiple laser parameters simultaneously: pulse width (10 ns to 1 ms), repetition frequency (1 Hz to 1 MHz), and power (1 W to 1 kW). By adjusting these parameters within specific ranges, the laser energy is controlled to achieve effective cutting while limiting heat-induced melting. This parameter optimization ensures that the electrode active material layer maintains its adhesive properties and does not fall off or peel during the cutting process.
2Manufacturing precision
If the outer circumferential edge part of the active material provided area is excised by laser, then the electrode plate is cut to desired size, but the electrode core melts by laser heat and mixes with electrode active material layer reducing adhesive property
Solution Approach 1:
The patent uses periodic pulse laser irradiation with controlled pulse width (10 ns to 1 ms) and repetition frequency (1 Hz to 1 MHz) to cut the electrode plate with high precision. The pulsed nature of the laser allows for precise control of heat input, enabling clean cuts at the outer circumferential edge without excessive melting of the electrode core. This prevents mixing of melted electrode core material with the electrode active material layer, maintaining the adhesive strength of the layered structure.
3Ease of manufacture
If high energy laser is irradiated to the core exposed area to form electrode tab, then the electrode tab is created, but sputter is scattered from the irradiated portion and becomes fine metal piece that easily falls off
Solution Approach 1:
The patent applies periodic pulse laser irradiation with specific parameters (pulse width 10 ns to 1 ms, repetition frequency 1 Hz to 1 MHz, power 1 W to 1 kW) to process the core exposed area for electrode tab formation. The pulsed irradiation mode allows controlled energy delivery that facilitates tab formation while minimizing sputter scattering. The intermittent nature of the pulses prevents continuous high-energy bombardment that would generate excessive sputter, thereby reducing the formation of loose fine metal pieces that could fall off.
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 inhibits the fall-off and peeling of conductive foreign substances, enhancing the safety and efficiency of secondary battery production by maintaining adhesive properties and reducing sputter scattering.
Implementation Method 1
a pulse laser is used to cut an active material provided area... a pulse laser is used to cut a core exposed area... by a pulse laser
Implementation Method 2
By doing this, it is possible to promptly cut the electrode core in a state that the melt amount is small
Implementation Method 3
fine metal piece (sputter) easily falls off or is peeled off... sputter scattering during laser cutting
Data Source
AI summary
According to the present disclosure, it is possible to inhibit the electrically conductive foreign substance from falling off and being peeled off from the electrode plate that has been already manufactured, so as to contribute in improving the safety property of the secondary battery. The manufacturing method of the electrode plate herein disclosed includes a precursor preparing step for preparing an electrode precursor 20A including an active material provided area A1 in which an electrode active material layer 24 is provided on a surface of the electrode core 22 and including a core exposed area A2 in which the electrode active material layer 24 is not provided and the electrode core 22 is exposed, and an active material provided area cutting step for cutting the active material provided area A1 by a pulse laser, and a core exposed area cutting step for cutting the core exposed area A2 by the pulse laser. Then, in the case where the pulse width (ns) of the pulse laser is represented by X and the lap rate (%) is represented by Y for the core exposed area cutting step, a condition represented by Y≥−3 log X+106 is satisfied. According to the manufacturing method of the electrode plate as described above, it is possible to inhibit the electrically conductive foreign substance from falling off and being peeled off from the electrode plate that has been already manufactured, and thus it is possible to contribute in improving the safety property of the secondary battery.