Lithium secondary battery and its manufacturing method and manufacturing device

Abstract

Conventionally, when coating electrodes of a lithium secondary battery and insulating material as a separator, the coverage of the insulating material deteriorates at the edge of the electrode layer, and the risk of failure due to short circuit increases. In order to solve the above-mentioned problems, the present invention applies the electrode material to the electrode substrate supplied at a predetermined speed, applies the first insulating material to the adjacent parts of the electrode material on both sides of the electrode substrate in the direction perpendicular to the supply direction, and applies the first insulating material to the electrode substrate. The surface of the coated electrode material and the first insulating material is coated with the second insulating material, and the coated electrode material, the first insulating material, and the second insulating material are dried and fixed. Thereby, since the insulating layer coverage of the edge part of the electrode layer by an electrode material improves, short-circuit faults can be reduced even when an electrode layer is thick.

Description

technical field [0001] The present invention relates to a lithium secondary battery and its manufacturing method and manufacturing device, in particular to a lithium secondary battery constituted by coating a positive electrode, a negative electrode, and a separator electrically separating the positive electrode and the negative electrode, and its manufacturing method and manufacturing device. Background technique [0002] With the development of portable electronic devices, small secondary batteries capable of repeated charging are used as power sources for these portable electronic devices. Among them, a lithium secondary battery having high energy density, long cycle life, low self-discharge property, and high operating voltage has attracted attention. Due to the above-mentioned advantages, lithium secondary batteries are widely used in portable electronic devices such as digital cameras, notebook computers, and mobile phones. Furthermore, in recent years, as batteries f...

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Problems solved by technology

[0004] Japanese Patent Application Laid-Open No. 2003-045491 (Patent Document 1) discloses the following technology: In the conventional electrode manufacturing method, a positive electrode film and a negative electrode film are formed separately, a separator film is attached to the negative electrode film, and the above-mentioned The positive electrode film is laminated on the negative electrode film with the separator to form an electrode winding body. However, in such a conventional electrode manufacturing method, the number of steps is large, and the electrode winding body is stacked with a plurality of sheets of the above-mentioned electrode winding body. It is very difficult to inject the electrolytic substance in the form of a solution, and many defective products are produced. Therefore, the technology of these points has been improved.

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