Active materials, electrodes, secondary batteries, battery packs, and vehicles

Abstract

To provide an active material that can be used to achieve a secondary battery with excellent charge / discharge efficiency and cycle life performance.SOLUTION: The active material includes a niobium-titanium oxide phase with a monoclinic crystal structure. The niobium-titanium oxide phase has a crystal structure that contains at least one octahedral site in the unit cell with a bond angle distortion of 0.8 σ2 / deg2 or less at the (Nb, Ti)O6 octahedral site, which is composed of only vertex sharing in the crystal lattice. The crystallite size of the niobium-titanium oxide phase is in the range of 85 nm or more and 130 nm or less.SELECTED DRAWING: Figure 3

Claims

1. It contains primary particles of a niobium-titanium oxide phase having a monoclinic structure, wherein the niobium-titanium oxide phase is composed solely of vertex-sharing (Nb, Ti)O2 in its crystal lattice. 6 The bond angle strain at the octahedral site is 0.8 σ 2 / deg 2 An active material having a crystal structure containing at least one octahedral site in its unit cell, wherein the crystallite size of the niobium titanium oxide phase is in the range of 85 nm to 130 nm, and the average particle diameter D 50 of the primary particles is in the range of 0.1 μm to 10 μm.

2. The niobium titanium oxide phase is Nb 2 TiO 7 Phase and Nb 10 Ti 2 O 29 The active material according to claim 1, comprising at least one phase selected from the group consisting of phases.

3. The active material according to claim 2, wherein the at least one phase contains at least one selected from the group consisting of K, Zr, Sn, V, Ta, Mo, W, P, Y, Fe, Co, Cr, Mn, Ni, and Al.

4. The niobium titanate oxide phase has a monoclinic crystal structure belonging to the space group C2 / m, and the bond angle strain at the 2a site described in the symmetry of International Tables Volume A in the monoclinic crystal structure is 0.8 σ 2 / deg 2 The active material according to claim 1 or 2, wherein the bond angle strain is as described below.

5. An electrode comprising the active material according to claim 1 or 2.

6. The electrode according to claim 5, wherein the electrode includes an active material-containing layer containing the active material.

7. Positive electrode and, The negative electrode and, Electrolytes and A secondary battery comprising, The secondary battery wherein the negative electrode is the electrode described in claim 5.

8. A battery pack comprising the secondary battery described in claim 7.

9. External terminals for power supply, Protection circuit and The battery pack according to claim 8, further comprising the above.

10. The device comprises multiple secondary batteries, The battery pack according to claim 8, wherein the secondary batteries are electrically connected in series, in parallel, or in a combination of series and parallel.

11. A vehicle equipped with the battery pack described in claim 8.

12. The vehicle according to claim 11, which includes a mechanism for converting the kinetic energy of the vehicle into regenerative energy.

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