Battery electrodes and batteries

Abstract

To improve the rate performance.SOLUTION: An electrode for a battery includes a base material and a negative electrode active material layer. The negative electrode active material layer is disposed on a surface of the base material. A cross section parallel to a thickness direction of the negative electrode active material layer includes a first region and a second region. In the thickness direction, the first region is disposed between the second region and the base material. The first region includes a first active material and a first binder. The second region includes a second active material and a second binder. Relations of A2<A1 and B2<B1 are satisfied or relations of A2>A1 and B2>B1 are satisfied. A1 represents an aspect ratio of the first active material. A2 represents an aspect ratio of the second active material. B1 indicates an area fraction of the first binder in the first region. B2 indicates an area fraction of the second binder in the second region.SELECTED DRAWING: Figure 1

Claims

1. It comprises a substrate and a negative electrode active material layer, The negative electrode active material layer is disposed on the surface of the substrate, The cross-section parallel to the thickness direction of the negative electrode active material layer includes a first region and a second region. In the thickness direction, the first region is located between the second region and the substrate. The first region comprises a first active material and a first binder. The second region comprises a second active material and a second binder. The relationship between equation (1) and equation (2) below is satisfied, or the relationship between equation (3) and equation (4) below is satisfied. A2 < A1 (1) B2 < B1 (2) A2 > A1 (3) B2 > B1 (4) In equations (1) to (4) above, A1 represents the aspect ratio of the first active material. A2 represents the aspect ratio of the second active material. B1 represents the area fraction of the first binder in the first region, and, B2 represents the area fraction of the second binder in the second region. Electrodes for batteries.

2. The negative electrode active material layer has a curvature of 1.8 or less. Battery electrode according to claim 1.

3. The relationship in equation (5) below is also satisfied, 0.05≦I 110 / I 002 (5) In the above formula (5), I 110 This indicates that the (110) plane diffraction intensity is shown in the X-ray diffraction profile of the negative electrode active material layer, I 002 This indicates the diffraction intensity of the (002) plane in the X-ray diffraction profile of the negative electrode active material layer. Battery electrode according to claim 1.

4. Of the relationships given by equation (1) and equation (2), or the relationships given by equation (3) and equation (4), only the relationship given by equation (1) and equation (2) is satisfied. Battery electrode according to any one of claims 1 to 3.

5. The first active material and the second active material each independently contain artificial graphite. Battery electrode according to any one of claims 1 to 3.

6. The negative electrode active material layer is 20 mg / cm³ 2 Having the above basis weight, and 1.1 to 1.6 g / cm³ 3 Having a density of, Battery electrode according to any one of claims 1 to 3.

7. The relationship in equation (6) below is also satisfied, 0.5≦Tx / (T1+T2)≦0.7 (6) In the above formula (6), T1 indicates the thickness of the first region, T2 indicates the thickness of the second region, When the relationship in equation (1) above is satisfied, Tx represents the thickness of the first region, and If the relationship in equation (3) above is satisfied, Tx represents the thickness of the second region. Battery electrode according to any one of claims 1 to 3.

8. The relationship in equation (7) below is also satisfied, 1.8%≦|B1-B2| (7) Battery electrode according to any one of claims 1 to 3.

9. The relationship in equation (8) below is also satisfied, 1.8 ≤ Ax (8) In the above formula (8), When the relationship in equation (1) above is satisfied, Ax represents the aspect ratio of the first active material, and If the relationship in equation (3) above is satisfied, Ax represents the aspect ratio of the second active material. Battery electrode according to any one of claims 1 to 3.

10. Includes a battery electrode according to any one of claims 1 to 3, battery.

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