Battery cells, batteries and power consumption devices

Abstract

This application relates to a battery cell, a battery and a power consumption device, wherein the battery cell includes an electrolyte, an electrode assembly and a housing, the housing containing the electrode assembly and the electrolyte, the housing having a cylindrical structure, and the electrolyte containing a linear ester solvent, the mass content of the linear ester solvent in the electrolyte being 25.5 wt% or more. The magnification performance and reliability of the battery cell in the embodiment of this application can be improved.

Claims

1. A battery cell comprising a housing, an electrode assembly, and an electrolyte, wherein the housing houses the electrode assembly and the electrolyte, The housing has a cylindrical structure, The electrolyte contains a linear ester solvent, and the mass content of the linear ester solvent in the electrolyte is 25.5 wt% or more, in a battery cell.

2. The battery cell according to claim 1, wherein the mass content of the chain-like ester solvent in the electrolyte is 25.5 wt% to 76.5 wt%.

3. The battery cell according to claim 2, wherein the mass content of the chain-like ester solvent in the electrolyte is 25.5 wt% to 70 wt%.

4. The battery cell according to claim 3, wherein the mass content of the chain-like ester solvent in the electrolyte is 42.5 wt% to 70 wt%.

5. The battery cell according to any one of claims 1 to 4, wherein the chain-like ester solvent comprises a chain-like carbonate, and the mass content of the chain-like carbonate in the electrolyte is 4 wt% to 70 wt%.

6. The battery cell according to claim 5, wherein the mass content of the chain carbonate in the electrolyte is 4 wt% to 42.5 wt%.

7. The aforementioned chain-like carbonate comprises a compound represented by formula I, 【Chemistry 1】 In equation I, R １１ and R １２ The battery cell according to any one of claims 1 to 6, wherein each independently comprises a C1-C3 alkyl group or a C1-C3 haloalkyl group.

8. R １１ and R １２ The battery cell according to claim 7, wherein each independently comprises a C1-C3 alkyl group or a C1-C3 fluoroalkyl group.

9. The battery cell according to claim 7 or 8, wherein the chain-like carbonate comprises one or more compounds represented by formula I-1 to formula I-6. 【Chemistry 2】

10. The battery cell according to any one of claims 5 to 9, wherein the chain-like carbonate comprises a compound represented by formula I-1. 【Transformation 3】

11. The battery cell according to any one of claims 1 to 10, wherein the chain-like ester solvent further comprises a chain-like carboxylic acid ester, and the mass content of the chain-like carboxylic acid ester in the electrolyte is 4 wt% to 70 wt%.

12. The battery cell according to claim 11, wherein the mass content of the chain-like carboxylic acid ester in the electrolyte is 8.5 wt% to 60 wt%.

13. The aforementioned linear carboxylic acid ester includes the compound represented by formula II, 【Chemistry 4】 In Equation II, R ２１ It contains a hydrogen atom, a halogen atom, a C1-C3 alkyl group or a C1-C3 haloalkyl group, R ２２ The battery cell according to claim 11 or 12, comprising a C1-C3 alkyl group or a C1-C3 haloalkyl group.

14. R ２１ is comprising a hydrogen atom, a fluorine atom, a C1-C3 alkyl group or a C1-C3 fluoroalkyl group, and / or R ２２ The battery cell according to claim 13, comprising a C1-C3 alkyl group or a C1-C3 fluoroalkyl group.

15. The battery cell according to claim 13 or 14, wherein the chain-like carboxylic acid ester comprises one or more compounds represented by formula II-1 to formula II-6. 【Transformation 5】

16. The battery cell according to claim 15, wherein the chain-like carboxylic acid ester comprises one or more compounds represented by formula II-2 and formula II-3.

17. The aforementioned chain-like carbonate comprises the compound represented by formula I-1, 【Transformation 6】 The mass content of the compound represented by formula I-1 in the electrolyte is 8.5 wt% to 35 wt%, The battery cell according to claim 16, wherein the chain-like carboxylic acid ester comprises a compound represented by formula II-2 and a compound represented by formula II-3, and the mass content of the compound represented by formula II-2 and the compound represented by formula II-3 in the electrolyte is 20 wt% to 55 wt%.

18. The battery cell according to any one of claims 1 to 17, wherein the housing includes a case and an end cap, the case includes a side wall and an end wall connected to the side wall, the case has an opening, the end cap is connected to the side wall and covers the opening, and the end cap and the end wall face each other along the axial direction of the housing.

19. The battery cell according to claim 18, wherein the matrix material of the side wall is steel, and the thickness of the side wall is 0.30 mm to 1.2 mm.

20. The battery cell according to claim 19, wherein the thickness of the side wall is 0.30 mm to 0.55 mm.

21. The battery cell according to any one of claims 18 to 20, wherein the side wall and the end wall are integrally formed structures.

22. The battery cell according to any one of claims 18 to 21, wherein the end cap is provided with a pressure release mechanism.

23. The battery cell according to claim 22, wherein the pressure relief mechanism includes a weak portion, the matrix material of the weak portion includes steel, and the thickness of the weak portion is 0.01 mm to 0.3 mm.

24. The battery cell according to claim 23, wherein the thickness of the weak portion is 0.05 mm to 0.2 mm.

25. The battery cell according to claim 23 or 24, wherein the end cap is provided with a recess, and the bottom wall of the recess is the weak portion.

26. The battery cell further includes electrode terminals installed on the end wall, The battery cell according to any one of claims 18 to 25, wherein the battery cell includes an electrode assembly housed in the case, the electrode assembly includes a first tab and a second tab of opposite polarity, the first tab being electrically connected to the end wall, and the second tab being electrically connected to the electrode terminal.

27. The battery cell according to any one of claims 1 to 26, wherein the size of the housing along its own axial direction is 1.3 to 2.5 times the size of the housing along its own radial direction.

28. The size of the housing along its own axial direction is 50 mm to 150 mm, and / or The battery cell according to any one of claims 1 to 27, wherein the size of the housing along its own radial direction is 40 mm to 80 mm.

29. The battery cell according to any one of claims 1 to 28, wherein the electrolyte solution comprises an electrolyte salt, the electrolyte salt comprises a hexafluorophosphate and a sulfonylimide salt, and the molar concentration of the hexafluorophosphate is 0.9 mol / L or less.

30. The battery cell according to claim 29, wherein the molar concentration of the hexafluorophosphate is 0.2 mol / L to 0.8 mol / L.

31. The battery cell according to claim 29 or 30, wherein the ratio of the molar concentration of the sulfonylimide salt to the molar concentration of the hexafluorophosphate salt is 0.06 to 6.

32. The battery cell according to any one of claims 29 to 31, wherein the molar concentration of the electrolyte salt is 0.5 mol / L to 2 mol / L.

33. The sulfonylimide salt contains the anion represented by formula A, 【Transformation 7】 In formula A, R １ and R ２ each independently contains a halogen atom or a C1-C6 haloalkyl group, and the battery cell according to any one of claims 29 to 32.

34. The halogen atom includes a fluorine atom and / or The battery cell according to claim 33, wherein the C1-C6 haloalkyl group comprises a C1-C6 fluoroalkyl group.

35. R １ and R ２ The battery cell according to claim 33 or 34, wherein each independently comprises a fluorine atom or a C1-C3 fluoroalkyl group.

36. The battery cell according to any one of claims 33 to 35, wherein the anion represented by formula A includes one or more anions represented by formulas A-1 to A-5. 【Transformation 8】

37. The battery cell according to claim 36, wherein the anion represented by formula A includes one or more of the anions represented by formula A-1 to formula A-2. 【Chemistry 9】

38. The battery cell according to any one of claims 1 to 37, wherein the housing includes a housing body and a film layer, the film layer is installed on at least the surface of the housing body facing the electrolyte, and the matrix element of the film layer is nickel.

39. The battery cell according to claim 38, wherein the thickness of the film layer is 1.5 μm to 6.0 μm.

40. The battery cell according to claim 38 or 39, wherein the mass content of the nickel element in the film layer is 70 wt% to 100 wt%.

41. The film layer further contains an iron element, the mass content of the iron element in the film layer is 0.1 wt% to 10 wt%, and / or The battery cell according to any one of claims 38 to 40, wherein the film layer further contains a carbon element, and the mass content of the carbon element in the film layer is 0.1 wt% to 15 wt%.

42. The battery cell according to any one of claims 38 to 41, wherein the matrix material of the housing body is steel.

43. A battery comprising a battery cell according to any one of claims 1 to 42.

44. A power consumption device including the battery described in claim 43.

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