Nonaqueous electrolyte battery and battery pack
A nonaqueous electrolyte battery according to one embodiment includes a negative electrode, a positive electrode and a nonaqueous electrolyte. The negative electrode includes a negative electrode active material-containing layer. The negative electrode active material-containing layer contains a negative electrode active material containing an orthorhombic Na-containing niobium titanium composite oxide. The positive electrode includes a positive electrode active material-containing layer. The positive electrode active material-containing layer contains a positive electrode active material. A mass C [g/m 2 ] of the positive electrode active material per unit area of the positive electrode and a mass A [g/m 2 ] of the negative electrode active material per unit area of the negative electrode satisfy the formula (1): 0.95≤A/C≤1.5.
1. A nonaqueous electrolyte battery, comprising:
a negative electrode comprising a negative electrode current collector and a negative electrode active material-containing layer provided on the negative electrode current collector, the negative electrode active material-containing layer comprising from 70% by mass to 96% by mass of a negative electrode active material, from 2% by mass to 28% by mass of a conductive material, and from 2% by mass to 28% by mass of a binder, the negative electrode active material consisting of an orthorhombic Na-containing niobium titanium composite oxide, the orthorhombic Na-containing niobium titanium composite oxide being represented by a general formula of
Li 2+v Na 2-y M1 x Ti 6-y-z nb y M2 z O 14+δ ,
wherein M1 is at least one selected from the group consisting of Cs, K, Sr, Ba, and Ca, M2 is at least one selected from the group consisting of Zr, Sn, V, Ta, Mo, W, Fe, Co, Mn, and Al, and 0≤v<2, 0≤x<2, 0.1≤y≤0.8, 0≤z<3, and −0.5≤δ≤0.5;
a positive electrode comprising a positive electrode current collector and a positive electrode active material-containing layer provided on the positive electrode current collector, the positive electrode active material-containing layer comprising a positive electrode active material; and
a nonaqueous electrolyte,
wherein a mass C [g/m 2 ] of the positive electrode active material per unit area of the positive electrode and a mass A [g/m 2 ] of the negative electrode active material per unit area of the negative electrode satisfy formula (1):
0.95≤ A/C≤ 1.5 (1).
2. The battery of claim 1 , wherein formula (2) is satisfied:
C A >C C (2)
wherein the C C [mAh/cm 2 ] is an electrode capacity per 1 cm 2 of the positive electrode, and the C A [MAh/cm 2 ] is an electrode capacity per 1 cm 2 of the negative electrode.
3. The battery of claim 1 , wherein the positive electrode active material comprises a composite oxide represented by a general formula of Li u MeO 2 , wherein Me is at least one selected from the group consisting of Ni, Co, and Mn, and 0≤u≤1.
4. The battery of claim 1 , wherein the positive electrode active material comprises a lithium manganese composite oxide having a spinel-type structure.
5. The battery of claim 1 , wherein the positive electrode active material comprises
a lithium manganese composite oxide having a spinel-type structure, and
a composite oxide represented by a general formula of Li u MeO 2 , wherein Me is at least one selected from the group consisting of Ni, Co, and Mn, and 0≤u≤1.
6. The battery of claim 1 , wherein the positive electrode active material comprises
a lithium manganese composite oxide having a spinel-type structure, and
a lithium phosphorus oxide having an olivine structure.
7. A battery pack, comprising the battery of claim 1 .
8. The pack of claim 7 , comprising nonaqueous electrolyte batteries each of which is the nonaqueous electrolyte battery,
wherein the nonaqueous electrolyte batteries are electrically connected in series, in parallel, or in combination thereof.