Non-aqueous electrolyte secondary cell
View Patent ↗The present invention provides a non-aqueous electrolyte secondary battery having high energy density and satisfactory cycle performance by using an alloy comprising Ni and Sn as a negative active material. The non-aqueous electrolyte secondary battery comprises a negative electrode with a composite layer containing a negative active material, a positive electrode and a non-aqueous electrolyte. The negative active material consists of an alloy containing 5 to 25 mass % of nickel and 75 to 95 mass % of tin and the alloy contains Sn 4 Ni 3 phase and Sn phase. It is preferable that the content ratio of Sn 4 Ni 3 phase and Sn phase in the alloy be 0.2≦Z≦3, when m 1 is the mass of Sn 4 Ni 3 phase, m 2 is the mass of said Sn phase, and Z=m l /m 2 ; and that the composite layer contain carbon material.
1. A non-aqueous electrolyte secondary battery comprising:
a negative electrode with a composite layer containing a negative active material;
a positive electrode; and
a non-aqueous electrolyte;
characterized in that
said negative active material is an alloy containing 5 to 25 mass % of nickel and 75 to 95 mass % of tin,
said alloy contains Sn 4 Ni 3 phase and Sn phase, and
the content ratio of said Sn 4 Ni 3 phase and said Sn phase in said alloy is 0.2≦Z≦3 when m 1 is the mass of said Sn 4 Ni 3 phase, m 2 is the mass of said Sn phase, and Z=m 1 / m 2 .
2. The non-aqueous electrolyte secondary battery according to claim 1 , characterized in that said composite layer contains carbon material.
3. The non-aqueous electrolyte secondary battery according to claim 1 , characterized in that
said composite layer contains carbon material, and
when n 1 is the mass of said alloy, n 2 is the mass of said carbon material, and S =n 1 / n 2 , S falls within the range of 0.05≦S ≦3.5.
4. The non-aqueous electrolyte secondary battery according to claim 1 , characterized in that
in said composite layer, powdered negative active material is used, and
the porosity of said composite layer is 30 to 75%.
5. The non-aqueous electrolyte secondary battery according to claim 2 , characterized in that
in said composite layer, powdered negative active material is used, and
the porosity of said composite layer is 30 to 75%.
6. The non-aqueous electrolyte secondary battery according to claim 3 , characterized in that
in said composite layer, powdered negative active material is used, and
the porosity of said composite layer is 30 to 75%.
7. The non-aqueous electrolyte secondary battery according to claim 1 , characterized in that
the apparent density of said negative electrode is 2.5 to 8.3 g/cm 3 .
8. The non-aqueous electrolyte secondary battery according to claim 2 , characterized in that
the apparent density of said negative electrode is 2.5 to 8.3 g/cm 3 .
9. The non-aqueous electrolyte secondary battery according to claim 3 , characterized in that
the apparent density of said negative electrode is 2.5 to 8.3 g/cm 3 .
10. A non-aqueous electrolyte secondary battery comprising:
a negative electrode with a composite layer containing a negative active material;
a positive electrode; and
a non-aqueous electrolyte;
characterized in that
said negative active material is an alloy containing 5 to 25 mass % of nickel and 75 to 95 mass % of tin,
said alloy contains Sn 4 Ni 3 phase and Sn phase,
said alloy comprises Sn having a peak lying in a range of 30.5°≦2θ≦30.8° in X-ray diffraction obtained with CuKα 1 radiationm, and
the content ratio of said Sn 4 Ni 3 phase and said Sn phase in said alloy is 0.2≦Z≦3 when m 1 is the mass of said Sn 4 Ni 3 phase, m 2 is the mass of said Sn phase, and Z=m 1 / m 2 .