Lithium ion battery pole piece roll coated with white glue at bottom
By setting the bottom white glue layer and active material layer in the unit to be slit of the lithium-ion battery electrode roll, the problem of residual powder particles during the slit process is solved, and the self-discharge and safety of the battery are improved.
Patent Information
- Application Number
- CN202420331448.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-22
- Publication Date
- 2025-02-14
- Estimated Expiration
- 2034-02-22
AI Technical Summary
The powder particles generated by the electrode sheet of lithium-ion battery during the slitting process are difficult to remove, resulting in residual residue between the electrode sheet and the separator, affecting the self-discharge and safety of the battery.
The lithium-ion battery electrode roll with white glue on the bottom is composed of copper foil current collector, top white glue layer, bottom white glue layer and active material layer. The bottom white glue layer is set in the middle, and both sides are active The material layer, on the outside, is the top white glue layer and copper foil current collector.
It basically eliminates the residual and splashing problems of active material particles during the slitting process, improves the pass rate of Hipot's high-voltage insulation impedance test, reduces the chance of diaphragm damage, and improves the safety of battery use.
Smart Images
Figure CN222483398U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the field of batteries, and in particular relates to a lithium ion battery pole piece roll with white glue coated on the bottom. Background Art
[0002] When lithium-ion battery electrodes are cut, powder particles are generated that adhere to the fracture surface or fall on the battery surface and are difficult to remove.
[0003] After lamination or winding, a large number of powder particles adhere to the gap between the pole piece and the diaphragm. During the Hipot test, the external high voltage is easily broken or damaged. After the charge and discharge reaction, the powder particles are mixed between the diaphragm and the pole piece, which is easy to cause unpredictable self-discharge of the battery. If the battery is vibrated for a long time, the particle material will be displaced, affecting the self-discharge of the battery, and even affecting the safety of the battery under harsh conditions.
[0004] At present, the method to solve the powder falling off at the cutting edge mostly adopts the method of roller brush dust removal and ion wind dust removal for dust removal. However, after dust removal, there are still powder particles remaining on the diaphragm and the electrode of the dissected and stacked battery cells. Utility Model Content
[0005] The utility model aims to provide a lithium-ion battery pole piece roll with white glue coated on the bottom, so as to solve the problem of residual and splashing active material particles during the cutting process.
[0006] The utility model discloses a lithium ion battery pole piece roll with white glue coated on the bottom, which is composed of a plurality of units to be cut; the units to be cut are composed of a copper foil current collector, a top white glue layer, a bottom white glue layer and an active material layer; the bottom white glue layer is arranged in the middle, the two sides of the bottom white glue layer are respectively active material layers, the outer side of the active material layer is the top white glue layer, and the outer side of the top white glue layer is the copper foil current collector.
[0007] The beneficial effects of the utility model are:
[0008] The utility model can basically eliminate the problems of active material particles remaining and splashing during the slitting process, and can fundamentally solve the problem of active material particles falling on the pole piece and the diaphragm at the slitting edge. It can improve the pass rate of the Hipot high-voltage insulation impedance test process during the lamination or winding production process, reduce the probability of diaphragm damage, improve the pass rate of the Hipot process, and improve the safety of the battery during use.
[0009] The battery made of the pole piece of the utility model can improve the pass rate of the needle puncture test due to the insulation and high temperature resistance of the white glue layer at the bottom of the pole piece. In addition, during the thermal runaway process, the shrinkage of the bottom diaphragm is reduced, and the insulation and high temperature resistance of the bottom of the positive pole piece make it difficult to cause a bottom internal short circuit, which can reduce the severity of the thermal runaway process. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 A schematic diagram of the structure of a lithium-ion battery pole piece roll with white glue applied to the bottom;
[0011] Figure 2 This is a schematic diagram of the electrode after the lithium-ion battery electrode roll with white glue on the bottom is cut. DETAILED DESCRIPTION
[0012] The technical solution of the present invention is not limited to the specific implementation modes listed below, but also includes any combination of the specific implementation modes.
[0013] Specific implementation method one: This implementation method is described in conjunction with the accompanying drawings. In this implementation method, a lithium-ion battery pole piece roll with white glue coated on the bottom is composed of a number of units to be cut; the unit to be cut is composed of a copper foil current collector 1, a top white glue layer 2, a bottom white glue layer 3 and an active material layer 4; the bottom white glue layer 3 is arranged in the middle, and the two sides of the bottom white glue layer 3 are respectively the active material layer 4, the outer side of the active material layer 4 is the top white glue layer 2, and the outer side of the top white glue layer 2 is the copper foil current collector 1.
[0014] Specific embodiment 2: This embodiment is different from specific embodiment 1 in that the thickness of the bottom white glue layer 3 is twice the width of the top white glue layer 2. Other aspects are the same as specific embodiment 1.
[0015] Specific implementation method 3: This implementation method is different from the specific implementation method 1 in that the junction of the units to be cut and the midline position of the bottom white glue layer 3 are the cutting positions. The rest is the same as the specific implementation method 1.
[0016] Specific embodiment 4: This embodiment is different from specific embodiment 1 in that when the lithium-ion battery electrode roll with white glue on the bottom is used as a positive electrode, the active material layer 4 is a ternary material, PVDF, conductive agent, and NMP stirred by a mixer to form a slurry with a uniform and stable viscosity. The rest is the same as specific embodiment 1.
[0017] Specific embodiment 5: This embodiment is different from specific embodiment 4 in that: the ternary material is 5 series single crystal ternary material, 5 series polycrystalline ternary material, 6 series single crystal ternary material, 6 series polycrystalline ternary material, 7 series single crystal ternary material, 7 series polycrystalline ternary material, 8 series single crystal ternary material, 8 series polycrystalline ternary material, cobalt-free single crystal ternary material, cobalt-free polycrystalline ternary material, lithium iron phosphate material, polyanion sodium ion positive electrode material or layered oxide sodium ion-free positive electrode material. The rest is the same as specific embodiment 4.
[0018] Specific embodiment 6: This embodiment is different from specific embodiment 4 in that the top white glue layer 2 and the bottom white glue layer 3 are made of aluminum oxide, PVDF, and NMP stirred in a mixer to form a uniformly mixed white glue slurry. The rest is the same as specific embodiment 4.
[0019] In this embodiment, ternary materials, PVDF, conductive agent, and NMP are stirred by a mixer to form a uniform slurry with stable viscosity as the active material layer 4, and aluminum oxide, PVDF, and NMP (solvent) are stirred by a mixer to form a uniform white glue slurry as the bottom white glue layer 3, which is coated into a pole piece shape on an aluminum foil at one time by a slot extrusion coater, and the coated pole piece is rolled up by a coater oven;
[0020] After winding, the electrode piece returns to the coating machine head to be rewound, coated on both sides, and then dried by the coating machine and rolled up to form a positive electrode piece with symmetrical front and back sides and white glue coated on the bottom;
[0021] The prepared positive electrode sheet is rolled to the corresponding designed electrode sheet thickness using a double-roll calender, and then cut along the set cutting position using a slitting machine. After cutting, 6 rolls of electrode sheets with exactly the same size and white glue on the bottom are obtained, and the white glue on the bottom is the cut surface of the slitting knife.
[0022] Specific embodiment 7: This embodiment is different from specific embodiment 1 in that when the lithium-ion battery electrode roll with white glue on the bottom is used as a negative electrode, the active material layer 4 is a graphite material, SBR, conductive agent, and pure water stirred by a mixer to form a slurry with a uniform and stable viscosity. The rest is the same as specific embodiment 1.
[0023] Specific embodiment eight: This embodiment differs from specific embodiment seven in that the graphite material is natural graphite, artificial graphite material or hard carbon material. The rest is the same as specific embodiment seven.
[0024] Specific embodiment 9: This embodiment is different from specific embodiment 7 in that the top white glue layer 2 and the bottom white glue layer 3 are made of water-based aluminum oxide, SBR, and pure water through a mixer to form a uniformly mixed white glue slurry. The rest is the same as specific embodiment 7.
[0025] In this embodiment, graphite material, SBR, conductive agent, and pure water are stirred by a mixer to form a uniform slurry with stable viscosity as the active material layer 4, and aqueous aluminum oxide, SBR, and pure water are stirred by a mixer to form a uniform white glue slurry bottom white glue layer 3, which is coated into the shape of an electrode piece by a slit extrusion coater at one time and coated on aluminum foil, and the coated electrode piece is rolled up by the coater oven;
[0026] After winding, the electrode sheet returns to the coating machine head and is rewound, coated on both sides, and then dried by the coating machine and rolled up to form a negative electrode sheet with symmetrical front and back sides and white glue coated on the bottom;
[0027] The prepared positive electrode sheet is rolled to the corresponding designed electrode sheet thickness using a double-roll calender, and then cut along the set cutting position using a slitting machine. After cutting, 6 rolls of electrode sheets with exactly the same size and white glue on the bottom are obtained, and the white glue on the bottom is the cut surface of the slitting knife.
[0028] Specific embodiment 10: This embodiment differs from specific embodiment 1 in that the copper foil current collector 1 is copper foil, carbon-coated copper foil, other conductive metal foil, other conductive mesh foil or aluminum foil with any conductive material coated on the surface. The rest is the same as specific embodiment 1.
Claims
1. A lithium-ion battery pole piece roll with white glue on the bottom, characterized in that A lithium-ion battery pole piece roll with white glue coated on the bottom is composed of a plurality of units to be cut; the units to be cut are composed of a copper foil current collector (1), a top white glue layer (2), a bottom white glue layer (3) and an active material layer (4); the bottom white glue layer (3) is arranged in the middle, the two sides of the bottom white glue layer (3) are respectively the active material layers (4), the outer side of the active material layer (4) is the top white glue layer (2), and the outer side of the top white glue layer (2) is the copper foil current collector (1).
2. A lithium-ion battery pole piece roll with white glue on the bottom according to claim 1, characterized in that The thickness of the bottom white glue layer (3) is twice the width of the top white glue layer (2).
3. A lithium-ion battery pole piece roll with white glue on the bottom according to claim 1, characterized in that The junction of the units to be cut and the midline position of the bottom white glue layer (3) is the cutting position.