JP2008177595A5

JP2008177595A5 -

Info

Publication number: JP2008177595A5
Application number: JP2008040312A
Authority: JP
Filing date: 2008-02-21
Publication date: 2009-09-03
Anticipated expiration: 2026-12-06

Claims

A separator made of a porous membrane comprising a porous substrate having a 0.99 ° C. or more refractory temperature, and a resin B that swelling degree with only One temperature rise swells by absorbing the electrolytic solution by applying heat increases,
The porous membrane includes filler particles,
Formula (1) as defined in, the swelling degree B _R of the resin B at 25 ° C., a separator for an electrochemical element, characterized in that it is 2.5 or less.
B _R = (V ₀ / V _i ) −1 (1)
However, in the above formula, V ₀ is the volume of the resin B after 24 hours immersion at 25 ° C. in the electrolytic solution (cm ^3), V _i is the resin before immersion in electrolyte volume (cm ³⁾ Represent each.

Swelling degree B of the resin B _RR The separator for electrochemical devices according to claim 1, wherein is 1 or less.

The degree of swelling B of the resin B at 120 ° C., defined by the following formula (2) _TT The separator for electrochemical devices according to claim 1 or 2, wherein is 1 or more.
B _TT = (V ₁₁ / V ₀₀ -1 (2)
However, in the above formula, V ₀₀ Is the volume of resin B after immersing in an electrolyte at 25 ° C. for 24 hours (cm ^3Three ), V ₁₁ Is the volume of the resin B (cm ^3Three ) Respectively.

A porous substrate having a heat resistant temperature of 150 ° C. or higher;
A separator made of a porous film containing a resin B that absorbs an electrolyte solution by heating and swells and the degree of swelling increases with increasing temperature,
The porous membrane includes filler particles,
The separator for an electrochemical element, wherein the resin B is a crosslinked resin having a glass transition temperature in the range of 75 to 125 ° C.

The said resin crosslinked body is a crosslinked body of at least 1 sort (s) of resin chosen from the group which consists of a styrene resin, a styrene butadiene copolymer, an acrylic resin, a polyalkylene oxide, a fluororesin, and these derivatives. Electrochemical element separator.

The separator for an electrochemical element according to any one of claims 1 to 6, further comprising a resin A having a melting point in the range of 80 to 130 ° C.

The separator for an electrochemical element according to any one of claims 1 to 7, wherein at least a part of the porous substrate is composed of the filler particles.

The separator for an electrochemical element according to any one of claims 1 to 7, wherein the filler particles are contained in pores of the porous substrate.

The separator for electrochemical devices according to any one of claims 1 to 9, wherein the filler particles include plate-like particles.

The separator for an electrochemical element according to claim 1, wherein the filler particles are made of an inorganic oxide.

The separator for electrochemical devices according to any one of claims 1 to 10, comprising boehmite as the filler particles.

The separator for an electrochemical element according to any one of claims 1 to 12, wherein the porous substrate includes a fibrous material having a heat resistant temperature of 150 ° C or higher.

Positive electrode, a negative electrode, a nonaqueous electrolyte and an electrochemical device, which comprises a separator for an electrochemical device according to any one of claims 1 to 13.

The electrochemical device according to claim 14 , wherein the separator is integrated with at least one selected from a positive electrode and a negative electrode.