Lithium-ion secondary battery

Abstract

Provided is a lithium-ion secondary battery in which stable battery performance is ensured and a high degree of freedom in shape can be effectively exhibited and which can be advantageously made to have an improved output density, improved bending strength, and reduced size. This battery can be produced in a short cycle time and at low cost by means of the simplest possible equipment. The battery has been configured so as to have a layered object (18) which comprises a positive-electrode layer (12) constituted of a first vapor-deposited polymer film layer (26) containing a positive active material (24), a negative-electrode layer (14) constituted of a second vapor-deposited polymer film layer (30) containing a negative active material (28), and a solid electrolyte layer (16) constituted of a third vapor-deposited polymer film layer (32) having lithium-ion conductivity, the layer (12) and the layer (14) having been superposed through the layer (16).

Description

technical field [0001] The present invention relates to a lithium ion secondary battery, and in particular to an improvement of an all-solid lithium ion secondary battery having a laminate (power generating element) in which a positive electrode layer and a negative electrode layer are laminated with a solid electrolyte layer interposed therebetween. Background technique [0002] In general, lithium ion secondary batteries having high energy density are widely used as power sources in portable electronic devices such as notebook personal computers and mobile phones. In this lithium ion secondary battery, there are roughly two types, namely: a lithium ion secondary battery using a liquid type electrolyte (including a liquid electrolyte and a gel type electrolyte) for the electrolyte, and a so-called all-solid type using a solid electrolyte for the electrolyte Lithium-ion secondary battery. Of these two types of lithium-ion secondary batteries, the all-solid lithium-ion secon...

AI Technical Summary

Problems solved by technology

[0007] But on the other hand, in the lithium ion secondary battery, since the positive electrode layer, the negative electrode layer, and the solid electrolyte layer are all composed of inorganic substances, the flexibility and even softness of these layers are lacking, and as a source of sputtering The substrate (collector, etc.) formed by stacking the positive electrode layer and the solid electrolyte layer composed of the film layer is made of a hard material, so there is a problem that the overall lithium-ion secondary battery has a structure with low bending strength.

In addition, the film formation rate (film formation amount per unit time) of the positive electrode layer and the sputtered film layer constituting the solid electrolyte layer is remarkably low, so there is also a cycle time required for the manufacture of one lithium-ion secondary battery. long question

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