Nonaqueous electrolyte battery and battery pack

1. A nonaqueous electrolyte battery comprising:

a positive electrode;

a negative electrode containing monoclinic titanium dioxide or Li 4+a Ti 5 O 12 (here, −0.5≤a≤3) as an active material, and polyvinylidene fluoride with a molecular weight of 400,000 to 1,000,000 as a binder, the negative electrode satisfying a formula (I) below; and

a nonaqueous electrolyte containing at least one of difluorophosphate and monofluorophosphate,

0.1≤(P2/P1)≤0.4   (I),

wherein P1 is an intensity of a peak that appears within a range of 689 to 685 eV in a spectrum according to photoelectron spectrometry of a surface of the negative electrode, and P2 is an intensity of a peak that appears within a range of 684 to 680 eV in the spectrum.

2. The nonaqueous electrolyte battery according to claim 1 , wherein a mass concentration of the difluorophosphate or monofluorophosphate with respect to a mass of the nonaqueous electrolyte is in the range from 1000 ppm to 30,000 ppm.

3. The nonaqueous electrolyte battery according to claim 1 , wherein a proportion of F included in LiF to F present on the surface of the negative electrode is 20% or less.

4. The nonaqueous electrolyte battery according to claim 1 , wherein the polyvinylidene fluoride has a molecular weight of 400,000 to 700,000.

5. The nonaqueous electrolyte battery according to claim 1 , wherein a mixing ratio of the polyvinylidene fluoride is 5 parts by weight or less when the negative electrode is 100 parts by weight.

6. A battery pack comprising one or more nonaqueous electrolyte batteries according to claim 1 .

7. The battery pack according to claim 6 , further comprising an external terminal for distributing power.