Polymer electrolyte composition including polymer having a structural unit represented by formula (1), electrolyte salt, and molten salt, and polymer secondary battery including the same
There is disclosed a polymer electrolyte composition that comprises a polymer having a structural unit represented by the following formula (1), at least one electrolyte salt selected from the group consisting of lithium salts, sodium salts, and magnesium salts, and a molten salt having a melting point of 250° C. or less: wherein X − represents a counter anion.
1. A polymer electrolyte composition comprising:
a polymer having a structural unit represented by the following formula (1):
wherein X represents a counter anion;
at least one electrolyte salt selected from the group consisting of lithium salts, sodium salts, magnesium salts, and calcium salts; and
a molten salt having a melting point of 250° C. or less,
wherein the molten salt is at least one selected from the group consisting of 1-ethyl-3-methylimidazolium-bis(trifluoromethanesulfonyl)imide, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium-bis(trifluoromethanesulfonyl)imide, and N-ethyl-N-methylpyrrolidinium-bis(trifluoromethanesulfonyl)imide, and
wherein a content of the molten salt is 30% by mass or more and less than 55% by mass based on the total amount of the composition.
2. The polymer electrolyte composition according to claim 1 , wherein the composition is formed in sheet form.
3. The polymer electrolyte composition according to claim 1 , wherein the electrolyte salt is a lithium salt.
4. The polymer electrolyte composition according to claim 1 , wherein an anion of the electrolyte salt is at least one selected from the group consisting of PF 6 −, BF 4 −, N(SO 2 ) 2 −, N(CF 3 SO 2 ) 2 −, B(C 2 O 4 ) 2 −, and ClO 4 −.
5. The polymer electrolyte composition according to claim 1 , wherein a content of the at least one electrolyte salt is 3% by mass or more and 30% by mass or less.
6. The polymer electrolyte composition according to claim 1 , wherein a content of the at least one electrolyte salt is 3% by mass or more and 25% by mass or less.
7. The polymer electrolyte composition according to claim 1 , wherein a content of the at least one electrolyte salt is 3% by mass or more and 20% by mass or less.
8. The polymer electrolyte composition according to claim 1 , wherein the content of the molten salt is 50% by mass or less based on the total amount of the composition.
9. The polymer electrolyte composition according to claim 1 , wherein a content of the polymer having the structural unit represented by the formula (1) is 30% by mass or more and 60% by mass or less based on the total amount of the composition.
10. The polymer electrolyte composition according to claim 1 , wherein the polymer having a structural unit represented by the following formula (1) is represented by the following formula (2):
wherein n is 300 to 4000, and Y− represents a counter anion.
11. The polymer electrolyte composition according to claim 10 , wherein n is 400 to 3500.
12. The polymer electrolyte composition according to claim 10 , wherein n is 500 to 3000.
13. A polymer secondary battery comprising:
a positive electrode;
a negative electrode; and
an electrolyte layer comprising the polymer electrolyte composition according to claim 1 provided between the positive electrode and the negative electrode.