Positive Electrode Plate Structure for High-Density Embedded Tabs
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Solution Overview
Problem
Existing lithium-ion batteries with embedded tab structures suffer from reduced energy density due to uncoated zones requiring adhesive tapes, leading to poor interfaces and increased risks of lithium precipitation and overheating, while the tab welding process causes material instability and aging issues.
Innovation Solution
A single-sided groove embedded tab structure with a positive electrode plate design, using laser welding and specific active materials like manganese, iron, lanthanum, or zirconium, enhances energy density and safety by maintaining a smooth interface and improving thermal stability, with adjustments in welding parameters and material percentages to prevent detachment and heat accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If uncoated zones are provided on both sides of the electrode plate for embedded tab structure, then the tab connection is improved, but the energy density is reduced due to loss of active material areas
Solution Approach 1:
The patent applies asymmetry by providing an uncoated zone only on one side of the electrode plate instead of both sides. The first surface has a first uncoated zone for tab placement, while the second surface maintains full active material coating. This asymmetric design preserves energy density by retaining active material on one side while still achieving reliable tab connection through the uncoated zone on the other side.
2Stability of the object's composition
If adhesive tapes are used to cover uncoated zones, then the tab structure is stabilized, but the interface quality deteriorates leading to lithium precipitation and overheating risks
Solution Approach 1:
The patent extracts and removes the adhesive tape component from the embedded tab structure. By eliminating the adhesive tape entirely and relying on the uncoated zone design with proper current collector exposure, the patent avoids the interface quality deterioration, lithium precipitation, and overheating issues caused by adhesive tape while maintaining tab structure stability.
3Productivity
If laser welding is used for tab connection, then the welding efficiency is improved, but material instability and aging occur at the welding position
Solution Approach 1:
The patent applies local quality by creating a first uncoated zone that exposes the current collector surface in a specific local region. This localized exposure allows for controlled laser welding or resistance welding of the tab to the current collector, concentrating the welding heat in a defined area rather than affecting the entire electrode plate, thereby improving welding efficiency while minimizing material instability and aging.
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
The design improves energy density and safety performance by reducing lithium precipitation and material aging, ensuring strong connections and effective heat dissipation, resulting in enhanced cycling performance and reduced risk of overheating.
Implementation Method 1
The positive electrode connection portion is welded to the first surface through laser welding
Implementation Method 2
The selection of the element M within the above range and the adjustment of its percentage within the above range can help to improve the thermal stability of the second positive electrode active material, thereby alleviating the aging problem of the positive electrode plate and enhancing the safety performance of the electrochemical apparatus
Data Source
AI summary
An electrode assembly includes a positive electrode plate. The positive electrode plate features a single-sided groove embedded tab structure. The positive electrode plate includes a positive electrode current collector and a second positive electrode active material layer disposed on a second surface of the positive electrode current collector. The second positive electrode active material layer includes a second positive electrode active material, where the second positive electrode active material includes element M, and the element M includes at least one of manganese, iron, lanthanum, zirconium, or yttrium. The positive electrode plate of this application can enhance energy density of the electrochemical apparatus based on the existing embedded tab structure. At the same time, through the element M, thermal stability of the second positive electrode active material can be improved, thereby alleviating the aging problem of the positive electrode plate caused by the single-sided groove embedded tab structure.