Batteries and electrical devices

Abstract

This application discloses a battery and an electric device. The non-Faraday capacity of the negative electrode sheet is Cdl nF, and the sphericity of the negative electrode active material contained in the negative electrode sheet is S, and both of them satisfy the following characteristics, 0.5≦Cdl×S≦5. By adjusting the Cdl value and the sphericity S within the range of 0.5≦Cdl×S≦5, the specific surface area of ​​the negative electrode active material can be effectively reduced and its tap density can be improved, so that the negative electrode sheet has a relatively high density while preventing overpressure phenomenon, and the mechanical stress that the negative electrode active material of the negative electrode sheet receives during rolling can be minimized, the reaction area with the electrolyte can be minimized, and the battery can have good liquid retention performance, thereby preventing gas generation and swelling phenomenon from occurring, and thus the battery can have excellent multiplication performance and cycle performance.

Claims

1. The material comprises a positive electrode sheet, a negative electrode sheet, a separator, and an electrolyte, wherein the positive electrode sheet comprises a positive electrode current collector and a positive electrode film piece disposed on at least one surface of the positive electrode current collector, and the positive electrode film piece comprises a positive electrode active material. The negative electrode sheet comprises a negative electrode current collector and a negative electrode film piece disposed on at least one surface of the negative electrode current collector, the negative electrode film piece comprises a negative electrode active material, and the negative electrode active material comprises negative electrode active material granules having pores. The non-Faraday capacity of the negative electrode sheet is Cdl mF, the sphericity of the negative electrode active material is S, satisfying 0.5 ≤ Cdl × S ≤ 5, 0.5 ≤ Cdl ≤ 8, and 0.2 ≤ S ≤ 0.

9. battery.

2. The pore size distribution measured by the mercury intrusion method of the negative electrode active material is r nm, and Cdl and r satisfy 1.2 ≤ 0.1 × r + Cdl ≤ 10. The battery according to claim 1.

3. The pore size distribution of the negative electrode active material satisfies 2 ≤ r ≤ 20. The battery according to claim 2.

4. The negative electrode active material has at least one peak in the region where the pore size distribution is 2 nm to 6 nm. The battery according to claim 2.

5. The absorption time of the negative electrode film piece is T min, which is the time from when the electrolyte is dropped onto the negative electrode film piece in one drop until the electrolyte is completely absorbed, and the compressive density of the negative electrode film piece is PD g / cm ３ And satisfying 0.3 ≤ T × PD ≤ 5.8, The battery according to claim 1.

6. 0.25 ≤ T ≤ 3.5 and 1.1 ≤ PD ≤ 1.

7. The battery according to claim 5.

7. The negative electrode active material Dv50 is D １ The size is μm, and the Dv50 of the positive electrode active material is D ２ It is μm, and the D １ and D ２ This means that 1 ≤ D １ / D ２ Satisfying ≤ 36, The battery according to claim 1.

8. 6 ≤ D １ ≤ 18 The battery according to claim 7.

9. 0.5 ≤ D ２ ≤ 8 The battery according to claim 7.

10. The powder compression density of the aforementioned negative electrode active material at a pressure of 30 kN is P １ g / cm ３ Therefore, the powder compression density of the positive electrode active material at a pressure of 30 kN is P ２ g / cm ３ And the P １ and P ２ The relationship is 1.5 ≤ P ２ / P １ Satisfying ≤ 2.5, The battery according to claim 1.

11. 1.5 ≤ P １ ≤ 2.0 The battery according to claim 10.

12. 2 ≤ P ２ ≤ 4, The battery according to claim 10.

13. The negative electrode active material comprises a carbon material, and the carbon material comprises graphite. The battery according to claim 1.

14. An electrical device comprising a battery according to any one of claims 1 to 13, wherein the battery is used as a power supply for the electrical device. Electrical equipment.

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