Composition for non-aqueous secondary battery functional layer, functional layer for non-aqueous secondary battery, and non-aqueous secondary battery
Provided is a means for beneficially solving the problems of increasing separator productivity and further improving adhesion between an electrode and a separator in electrolysis solution while ensuring battery characteristics. A composition for non-aqueous secondary battery functional layer is provided that contains non-conductive inorganic particles and organic particles, wherein a difference in density between the non-conductive inorganic particles and the organic particles (non-conductive inorganic particles' density—organic particles' density) is 1.5 g/cm 3 or more, and the organic particles each have a core-shell structure having a core and a shell that partially covers an outer surface of the core, wherein the core is made of polymer having a degree of swelling in electrolysis solution of 5 times to 30 times, and the shell is made of polymer having a degree of swelling in electrolysis solution of greater than 1 time to 4 times.
1. A composition for non-aqueous secondary battery functional layer, comprising:
non-conductive inorganic particles; and
organic particles, wherein
a difference in density calculated by subtracting the organic particles' density from the non-conductive inorganic particles' density is 1.5 g/cm 3 or more, and
the organic particles each have a core-shell structure having a core and a shell that partially covers an outer surface of the core, wherein the core is made of polymer having a degree of swelling in electrolysis solution of 5 times to 30 times, and the shell is made of polymer having a degree of swelling in electrolysis solution of greater than 1 time to 4 times,
wherein the degree of swelling of polymer in electrolysis solution is calculated by W1/W0, where W0 indicates a weight of a film fabricated using the polymer, and W1 indicates a weight of the film after immersing into an electrolysis solution at 60° C. for 72 hours, the electrolysis solution being obtained by dissolving LiPF 6 into a mixture solvent of 68.5% by volume of ethylene carbonate, 30 vol % of diethyl carbonate, and 1.5 vol % of vinylene carbonate at a concentration of 1 mol/L.
2. The composition of claim 1 , wherein a percentage of an amount of the non-conductive inorganic particles contained in the composition relative to a total amount of the non-conductive inorganic particles and the organic particles contained in the composition is greater than 50% by mass to 98% by mass.
3. The composition of claim 1 , having a viscosity of 1 mPa·s to 100 mPa·s.
4. A functional layer for non-aqueous secondary battery formed by a method comprising:
applying onto a substrate the composition of claim 1 ; and
drying the composition applied.
5. The functional layer of claim 4 , exhibiting adhesion between a separator and an electrode of the non-aqueous secondary battery in electrolysis solution.
6. A non-aqueous secondary battery comprising:
a separator having the functional layer of claim 4 formed therein; and
an electrode.
7. The non-aqueous secondary battery of claim 6 , wherein the functional layer exhibits adhesion between the separator and the electrode of the non-aqueous secondary battery in electrolysis solution.
8. The functional layer of claim 5 , having peel strength of 1 N/m or more.
9. The non-aqueous secondary battery of claim 7 , wherein the functional layer has peel strength of 1 N/m or more.