Nonaqueous electrolyte secondary cell
View Patent ↗The present invention provides a non-aqueous electrolyte secondary cell that has good high-temperature cycle characteristics and good high-temperature standing resistance, and that is highly safe enough to prevent overcharge. The non-aqueous electrolyte secondary cell of the invention utilizes a non-aqueous electrolyte that includes a vinylene carbonate derivative, a cyclic sulfite derivative, and both/either of a phenylcycloalkane derivative and/or an alkylbenzene derivative having a quaternary carbon directly bonded to a benzene ring.
1. A non-aqueous electrolyte secondary cell comprising:
a positive electrode having a positive electrode active material intercalating and deintercalating lithium ions;
a negative electrode having a negative electrode active material intercalating and deintercalating lithium ions;
a non-aqueous electrolyte having a non-aqueous solvent and an electrolyte salt;
an outer casing can having mounted therein the positive electrode, the negative electrode, and the non-aqueous electrolyte, and having an opening portion; and
a sealing structure for sealing the opening portion and having a sealing plate;
wherein:
the positive electrode active material consists of a lithium cobalt oxide;
the positive electrode active material has a bulk density in the positive electrode of 3.3 g/cm 3 or more; and
the non-aqueous electrolyte includes a vinylene carbonate compound represented by Chemical Formula 1, a cyclic sulfite compound represented by Chemical Formula 2 or 3, and a phenylcycloalkane compound,
where R1 and R2 are independently a hydrogen atom or an alkyl group with two carbons or less,
where R1 to R4 are independently a hydrogen atom or an alkyl group with two carbons or less,
where R1 and R2 are independently a hydrogen atom or an alkyl group with two carbons or less.
2. The non-aqueous electrolyte secondary cell according to claim 1 , wherein:
when a total mass of the non-aqueous solvent and the electrolyte salt is taken as 100, an amount of the vinylene carbonate compound is 0.5 to 3 parts by mass per 100 total mass of the non-aqueous solvent and the electrolyte salt; and
an amount of the cyclic sulfite compound is 0.1 to 2 parts by mass per 100 total mass of the non-aqueous solvent and the electrolyte salt.
3. The non-aqueous electrolyte secondary cell according to claim 2 , wherein:
the vinylene carbonate compound is at least one selected from the group consisting of vinylene carbonate, methyl vinylene carbonate, and ethyl vinylene carbonate;
the cyclic sulfite compound is at least one selected from the group consisting of ethylene sulfite, vinylene sulfite, and methyl ethylene sulfite; and
the phenylcycloalkane compound is at least one selected from the group consisting of phenylcyclohexane, phenylcycloheptane, and phenylcyclopentane.
4. The non-aqueous electrolyte secondary cell according to claim 3 , wherein:
the amount of the phenylcycloalkane compound being 0.2 to 3 parts by mass per 100 total mass of the non-aqueous solvent and the electrolyte salt.
5. A non-aqueous electrolyte secondary cell comprising:
a positive electrode having a positive electrode active material intercalating and deintercalating lithium ions;
a negative electrode having a negative electrode active material intercalating and deintercalating lithium ions;
a non-aqueous electrolyte having a non-aqueous solvent and an electrolyte salt;
an outer casing can having mounted therein the positive electrode, the negative electrode, and the non-aqueous electrolyte, and having an opening portion; and
a sealing structure for sealing the opening portion and having a sealing plate;
wherein
the positive electrode active material consists of a lithium cobalt oxide;
the positive electrode active material has a bulk density in the positive electrode of 3.3 g/cm 3 or more; and
the non-aqueous electrolyte includes a vinylene carbonate compound represented by Chemical Formula 1, a cyclic sulfite compound represented by Chemical Formula 2 or 3, a phenylcycloalkane compound, and an alkylbenzene compound having a quaternary carbon directly bonded to a benzene ring,
where R1 and R2 are independently a hydrogen atom or an alkyl group with two carbons or less,
where R1 to R4 are independently a hydrogen atom or an alkyl group with two carbons or less,
where R1 and R2 are independently a hydrogen atom or an alkyl group with two carbons or less.
6. The non-aqueous electrolyte secondary cell according to claim 5 , wherein:
when a total mass of the non-aqueous solvent and the electrolyte salt is taken as 100, an amount of the vinylene carbonate compound is 0.5 to 3 parts by mass per 100 total mass of the non-aqueous solvent and the electrolyte salt; and
an amount of the cyclic sulfite compound is 0.1 to 2 parts by mass per 100 total mass of the non-aqueous solvent and the electrolyte salt.
7. The non-aqueous electrolyte secondary cell according to claim 6 , wherein:
the vinylene carbonate compound is at least one selected from the group consisting of vinylene carbonate, methyl vinylene carbonate, and ethyl vinylene carbonate;
the cyclic sulfite compound is at least one selected from the group consisting of ethylene sulfite, vinylene sulfite, and methyl ethylene sulfite;
the phenylcycloalkane compound is at least one selected from the group consisting of phenylcyclohexane, phenylcycloheptane, and phenylcyclopentane; and
the alkylbenzene compound is at least one selected from the group consisting of tert-butylbenzene, tert-amylbenzene, and tert-hexylbenzene.
8. The non-aqueous electrolyte secondary cell according to claim 7 , wherein a total amount of the phenylcycloalkane compound and the alkylbenzene compound is 0.2 to 3 parts by mass per 100 total mass of the non-aqueous solvent and the electrolyte salt.
9. A non-aqueous electrolyte secondary cell comprising:
a positive electrode having a positive electrode active material intercalating and deintercalating lithium ions;
a negative electrode having a negative electrode active material intercalating and deintercalating lithium ions;
a non-aqueous electrolyte having a non-aqueous solvent and
an electrolyte salt;
an outer casing can having mounted therein the positive electrode, the negative electrode, and the non-aqueous electrolyte, and having an opening portion; and
a sealing structure for sealing the opening portion and having a sealing plate;
wherein:
the positive electrode active material consists of a lithium cobalt oxide,
the positive electrode active material has a bulk density in the positive electrode of 3.3 g/cm 3 or more; and
the non-aqueous electrolyte includes a vinylene carbonate compound represented by Chemical Formula 1, a cyclic sulfite compound represented by Chemical Formula 2 or 3, and an alkylbenzene compound having a quaternary carbon directly bonded to a benzene ring:
where R1 and R2 are independently a hydrogen atom or an alkyl group with two carbons or less,
where R1 to R4 are independently a hydrogen atom or an alkyl group with two carbons or less,
where R1 and R2 are independently a hydrogen atom or an alkyl group with two carbons or less.
10. The non-aqueous electrolyte secondary cell according to claim 9 , wherein:
when a total mass of the non-aqueous solvent and the electrolyte salt is taken as 100, an amount of the vinylene carbonate compound is 0.5 to 3 parts by mass per 100 total mass of the non-aqueous solvent and the electrolyte salt; and
an amount of the cyclic sulfite compound is 0.1 to 2 parts by mass per 100 total mass of the non-aqueous solvent and the electrolyte salt.
11. The non-aqueous electrolyte secondary cell according to claim 10 , wherein:
the vinylene carbonate compound is at least one selected from the group consisting of vinylene carbonate, methyl vinylene carbonate, and ethyl vinylene carbonate;
the cyclic sulfite compound is at least one selected from the group consisting of ethylene sulfite, vinylene sulfite, and methyl ethylene sulfite:
the phenylcycloalkane compound is at least one selected from the group consisting of phenylcyclohexane, phenylcycloheptane, and phenylcyclopentane; and
the alkylbenzene compound is at least one selected from the group consisting of tert-butylbenzene, tert-amylbenzene, and tert-hexylbenzene.