Non-aqueous electrolyte secondary battery comprising phosphoric acid ester compound containing at least one metal element
View Patent ↗A non-aqueous electrolyte secondary battery includes an electrode assembly including a positive electrode including a positive electrode active material layer, a negative electrode, and a separator disposed between the positive electrode and the negative electrode; and a non-aqueous electrolyte, wherein at least one of the positive electrode and the separator contains a phosphoric acid ester compound containing at least one metal element and represented by a general formula (1) (where X and Y each represent a metal element, a hydrogen atom, or an organic group; at least one of X and Y represents a metal element; when the metal element is divalent, X and Y together represent a single metal element; and n represents an integer of 2 or more and 10 or less).
1. A non-aqueous electrolyte secondary battery comprising:
an electrode assembly having
a positive electrode including a positive electrode active material layer,
a negative electrode, and
a separator disposed between the positive electrode and the negative electrode; and
a non-aqueous electrolyte,
wherein at least one of the positive electrode and the separator contains a phosphoric acid ester compound containing at least one metal element and represented by a general formula (1)
where X and Y each represent a metal element, a hydrogen atom, or an organic group; at least one of X and Y represents a metal element; when the metal element is divalent, X and Y together represent a single metal element; and n represents an integer of 2 or more and 10 or less.
2. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the phosphoric acid ester compound is contained within the positive electrode active material layer.
3. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the phosphoric acid ester compound contains, as the metal element, at least one of Mg and Ca.
4. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the phosphoric acid ester compound is a cyclic phosphoric acid ester.
5. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the phosphoric acid ester compound is a metal salt of inositol-1,2,3,4,5,6-hexaphosphate having at least one metal element and represented by a general formula (2)
where X 1 to X 6 and Y 1 to Y 6 each represent a metal element, a hydrogen atom, or an organic group; at least one of X 1 to X 6 and Y 1 to Y 6 represents a metal element; when the metal element is divalent, X m and Y m together represent a single metal element where m represents an integer of 1 to 6.
6. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the phosphoric acid ester compound is a metal salt of myo-inositol-1,2,3,4,5,6-hexaphosphate having at least one metal element and represented by a general formula (3)
where X 1 to X 6 and Y 1 to Y 6 each represent a metal element, a hydrogen atom, or an organic group; at least one of X 1 to X 6 and Y 1 to Y 6 represents a metal element; when the metal element is divalent, X m and Y m together represent a single metal element where m represents an integer of 1 to 6.
7. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the phosphoric acid ester compound is a metal salt of myo-inositol hexaphosphate represented by a compositional formula of C 6 H 6 Ca m Mg 6−m O 24 P 6 where m satisfies 0≦m≦6.
8. The non-aqueous electrolyte secondary battery according to claim 1 , wherein a content of the phosphoric acid ester compound relative to the positive electrode active material layer is 0.1% by mass or more and 5% by mass or less.
9. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the non-aqueous electrolyte contains fluorinated ethylene carbonate.
10. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the positive electrode has
the positive electrode active material layer that includes
a first material mixture layer containing a positive electrode active material and the phosphoric acid ester compound and
a second material mixture layer containing a positive electrode active material, and a positive electrode current collector,
wherein the positive electrode current collector, the first material mixture layer, and the second material mixture layer are stacked in this order, and a concentration of the phosphoric acid ester compound contained within the positive electrode active material layer is higher in a portion close to the positive electrode current collector than in a surface layer portion of the positive electrode active material layer.