Nonaqueous electrolyte battery and battery pack
According to one embodiment, provided is a nonaqueous electrolyte battery including a positive electrode, a negative electrode, and a nonaqueous electrolyte. The negative electrode contains a negative electrode active material containing orthorhombic Na-containing niobium-titanium composite oxide particles represented by general formula (1) Li 2+v Na 2−y M1 x Ti 6−y−z Nb y M2 z O 14+δ . In general formula (1), M1 is one or two or more elements selected from the group consisting of Cs, K, Sr, Ba, and Ca, M2 is one or two or more elements selected from the group consisting of Zr, Al, Sn, V, Ta, Mo, W, Fe, Co, and Mn, 0≤v<2, 0≤x<2, 0<y<2, 0≤z<3, and −0.5≤δ≤0.5. The nonaqueous electrolyte contains an Na component in a range of 10 ppm by mass to 3,000 ppm by mass.
1. A nonaqueous electrolyte battery comprising:
a positive electrode;
a negative electrode comprising a negative electrode active material, the negative electrode active material comprising orthorhombic Na-containing niobium-titanium composite oxide particles represented by general formula (1) Li 2+v Na 2−y M1 x Ti 6−y−z Nb y M2 z O 14+δ , where M1 is at least one element selected from the group consisting of Cs, K, Sr, Ba, and Ca, M2 is at least one element selected from the group consisting of Zr, Al, Sn, V, Ta, Mo, W, Fe, Co, and Mn, 0≤v<2, 0≤x<2, 0<y≤0.8, 0≤z<3, and −0.5≤δ≤0.5;
a nonaqueous electrolyte comprising an Na component in a range of 10 ppm by mass to 3,000 ppm by mass; and
an organic film on a surface of the negative electrode,
wherein formula (2) is satisfied:
0.001≤( P 2/ P 1)≤0.25 (2)
wherein P1 is a C element concentration (atom %) obtained from an intensity of a peak appearing in a range of 289 eV to 294 eV in a spectrum according to X-ray photoelectron spectrometry for the negative electrode, and P2 is an Na element concentration (atom %) obtained from an intensity of a peak appearing in the range of 1.065 eV to 1.075 eV in the spectrum.
2. The nonaqueous electrolyte battery according to claim 1 , wherein the Na component comprises at least one of an Na ion and an Na-containing compound.
3. The nonaqueous electrolyte battery according to claim 2 , wherein the nonaqueous electrolyte further comprises a solvent comprising ethylene carbonate, and a content of the ethylene carbonate in the nonaqueous electrolyte falls within a range of 10% by mass to 30% by mass.
4. The nonaqueous electrolyte battery according to claim 1 , wherein the positive electrode comprises a positive electrode active material, the positive electrode active material comprising a spinel lithium-manganese composite oxide.
5. A battery pack comprising one or plural of the nonaqueous electrolyte battery according to claim 1 .
6. The nonaqueous electrolyte battery according to claim 1 , wherein the subscript y satisfies 0<y≤0.5.
7. The nonaqueous electrolyte battery according to claim 1 , wherein the subscript y satisfies 0.1≤y≤0.8.