A winding core that allows lithium-ion battery separators to breathe freely during storage

Abstract

The invention belongs to the technical field of lithium-ion battery diaphragm production, and in particular relates to a winding core for the lithium-ion battery diaphragm to breathe freely during storage, including a cylindrical hard winding core, and the side wall of the cylindrical hard winding core is The upper sleeve is provided with a long cylindrical air-permeable cushion made of microporous material, which is made of MDI or TDI polyurethane microporous elastomer material, with a density of 0.4-0.7g / cm3 and a pore size of 0.5-8μm . The beneficial effect of the present invention is that the outer wall of the hard core is covered with a long cylindrical air-permeable cushion made of microporous material. After the diaphragm is wound, the inner diaphragm can pass through the microporous structure of the air-permeable cushion and the outside air. Connected, free to "breathe" air, to ensure that the inner diaphragm will not be closed due to difficulty in contact with air during long-term storage, and to ensure that the performance of the diaphragm will not be reduced due to long storage time.

Description

technical field [0001] The invention belongs to the technical field of production of lithium-ion battery diaphragms, and in particular relates to a winding core for the lithium-ion battery diaphragms to breathe freely during storage. Background technique [0002] Although the performance of the lithium-ion battery separator depends to a certain extent on the characteristics of its raw materials and the advanced nature of the membrane production process, how to ensure that the performance of the separator does not decrease during the production process, especially in the subsequent processing process, is also a matter of lithium-ion batteries. One of the core technologies of battery separator production. In the existing diaphragm production process, the storage method and processing method of the diaphragm after the hole making is the main reason for the performance degradation of the diaphragm product. According to incomplete statistics, 80% of the performance reduction of t...

AI Technical Summary

Problems solved by technology

During the production process, the diaphragm is tightly wrapped on the surface of the smooth paper tube, so that the diaphragm in contact with the paper roll cannot be in contact with the air, so that there is not enough air in the micropores of the diaphragm

When the diaphragm is in this state for a long time, irreversible damage will be formed; if the concentricity of the paper core is not enough, radial runout may occur during the diaphragm winding, resulting in inconsistent winding tension of the diaphragm. When the diaphragm is wound, Sometimes tight, sometimes loose, the diaphragm will also be damaged or cause inconsistent performance of the diaphragm in this case

After the paper roll core has been used for a long time, its surface wax wears away, causing the surface of the roll core to be rough and uneven, which in turn causes damage to the diaphragm

All of the above aspects can lead to a decline in the quality and performance of the diaphragm.

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