Electrochemical element separator and electrochemical element obtained using same

Abstract

The purpose of the present invention is to provide: an electrochemical element separator that has excellent manufacturing stability, is without pinholes and has low internal resistance; and an electrochemical element that is obtained using the same. Provided is an electrochemical element separator comprising: a nonwoven substrate; and an inorganic particle layer that contains inorganic particles. The electrochemical element separator is characterized: in that a main constituent of the nonwoven substrate is synthetic resin fibers with an average fiber diameter of 1 to 20 [mu]m; in that the inorganic particle layer includes an inorganic particle layer A that contains magnesium hydroxide with an average particle diameter of 2.0 to 4.0 [mu]m, and an inorganic particle layer B that contains magnesium hydroxide with an average particle diameter of at least 0.5 [mu]m and less than 2.0 [mu]m; and in that the inorganic particle layer A and the inorganic particle layer B are stacked in this order on one surface of the nonwoven substrate; or in that the inorganic particle layer A is provided on one surface of the nonwoven substrate and the inorganic particle layer B is provided on the other surface thereof. The electrochemical element is obtained using the electrochemical element separator.

Description

technical field [0001] The present invention relates to a separator for electrochemical elements and an electrochemical element using the same. Background technique [0002] The separator for the electrochemical element is built in the electrochemical element. The separator for electrochemical elements plays a role in preventing direct contact between the positive electrode and the negative electrode in the electrochemical element. That is, the separator for the electrochemical element isolates the positive electrode and the negative electrode without internal short circuit. In order to reduce the internal resistance of the electrochemical element, it is necessary to form pores capable of effectively permeating ions of the electrolyte in the separator for an electrochemical element. Therefore, the separator for electrochemical elements needs to be porous. [0003] As a lithium ion secondary battery separator used as one type of electrochemical element, resin porous membra...

AI Technical Summary

Problems solved by technology

However, when such a resin porous film is used as a separator for a lithium ion secondary battery, there is a problem that melting and shrinkage occur when the battery generates abnormal heat, and the function of separating the positive and negative electrodes is lost, resulting in significant damage. internal short circuit

However, in the separators for capacitors described in Patent Documents 5 to 9, when the thickness is reduced to reduce the internal resistance, there is a problem that pinholes are likely to occur and internal short circuits are likely to occur.

Images