Nonaqueous electrolyte secondary battery and method of manufacturing nonaqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-10236530-B2
Application number	US-201615341447-A
Country	US
Kind code	B2
Filing date	Nov 2, 2016
Priority date	Nov 4, 2015
Publication date	Mar 19, 2019
Grant date	Mar 19, 2019

Abstract

A method of manufacturing a nonaqueous electrolyte secondary battery includes: manufacturing a positive electrode sheet by forming a positive electrode active material layer, which includes trilithium phosphate, on a positive electrode current collector foil; accommodating the positive electrode sheet, a negative electrode sheet, and an electrolytic solution in a battery case; and charging a battery after the accommodation. During the manufacturing of the positive electrode sheet, a positive electrode active material is a composite oxide including at least lithium and manganese. During the manufacturing of the positive electrode sheet, a conductive additive is obtained by attaching at least one of manganese or manganese oxide to a surface of a carbon material.

First claim

What is claimed is:

1. A nonaqueous electrolyte secondary battery, comprising:
a positive electrode sheet;
a negative electrode sheet;
a nonaqueous electrolytic solution that includes an ionic compound including fluorine; and
a battery case that accommodates the positive electrode sheet, the negative electrode sheet, and the nonaqueous electrolytic solution, wherein
the positive electrode sheet includes a positive electrode current collector foil and a positive electrode active material layer that includes a positive electrode active material and a conductive additive,
the positive electrode active material has a composite oxide and a first film on a surface of the composite oxide including lithium and manganese,
the conductive additive has a carbon material and a second film on a surface of the carbon material, and
the first film and the second film each include fluorine, manganese, and phosphorus.

2. The nonaqueous electrolyte secondary battery according to claim 1 , wherein
the first film and the second film comprise Mn X PO 5 F Y , and
X and Y are variables which vary depending on valences of manganese and phosphorus.

3. A method of manufacturing a nonaqueous electrolyte secondary battery,
the nonaqueous electrolyte secondary battery including a positive electrode sheet, a negative electrode sheet, a nonaqueous electrolytic solution that includes an ionic compound including fluorine, and a battery case that accommodates the positive electrode sheet, the negative electrode sheet, and the nonaqueous electrolytic solution,
the method comprising:
manufacturing the positive electrode sheet by forming a positive electrode active material layer, which includes a positive electrode active material and a conductive additive, on a surface of a positive electrode current collector foil;
accommodating the positive electrode sheet, the negative electrode sheet, the nonaqueous electrolytic solution, and trilithium phosphate in the battery case to form a pre-charged battery; and
charging the pre-charged battery after the positive electrode sheet, the negative electrode sheet, the nonaqueous electrolytic solution, and the trilithium phosphate are accommodated, wherein
in the manufacturing of the positive electrode sheet, the positive electrode active material is a composite oxide including lithium and manganese, and the conductive additive is obtained by attaching at least one of manganese and manganese oxide to a surface of a carbon material,
the method further comprising:
manufacturing the conductive additive, before the positive electrode sheet is manufactured, by preparing a mixture of the carbon material, one of a permanganate and a manganate, and water and reducing one of the permanganate and the manganate so as to attach the manganese oxide to the carbon material, wherein,
charging the pre-charged battery forms a film derived from the trilithium phosphate on the surface of the positive electrode active material.

4. The method according to claim 3 , wherein
an atomic ratio of manganese to carbon in the conductive additive is 0.05 or higher.

5. The method according to claim 3 , wherein
an atomic ratio of manganese to carbon in the conductive additive is 0.10 or lower.

6. The nonaqueous electrolyte secondary battery according to claim 1 , wherein
the ionic compound including fluorine is selected from the group consisting of LiPF 6 , LiBF 4 , LiAsF 6 , LiCF 3 SO 3 , LiC 4 F 9 SO 3 , LiN(CF 3 SO 2 ) 2 , and LiC(CF 3 SO 2 ) 3 .

7. The nonaqueous electrolyte secondary battery according to claim 1 , wherein
the positive electrode active material layer further comprises a binder.

8. The nonaqueous electrolyte secondary battery according to claim 7 , wherein
the binder is polyvinylidene fluoride.

9. The nonaqueous electrolyte secondary battery according to claim 1 , wherein
the composite oxide of the positive electrode active material comprises a compound obtained by substituting a part of manganese (Mn) in lithium manganese oxide (LiMn 2 O 4 ) having a spinel crystal structure with a transition metal.

10. The nonaqueous electrolyte secondary battery according to claim 1 , wherein
the composite oxide of the positive electrode active material is LiNi 1/2 Mn 3/2 O 4 .

11. The nonaqueous electrolyte secondary battery according to claim 1 , wherein
the carbon material of the conductive additive is a carbon black selected from the group consisting of acetylene black (AB), ketjen black, furnace black, and channel black.

12. The nonaqueous electrolyte secondary battery according to claim 1 , further comprising a separator between the positive electrode sheet and the negative electrode sheet.

13. The nonaqueous electrolyte secondary battery according to claim 1 , wherein
the negative electrode sheet includes a negative electrode current collector foil and a negative electrode active material layer that includes a negative electrode active material and a binder.

14. The method according to claim 3 , wherein
the carbon material of the conductive additive is a carbon black selected from the group consisting of acetylene black (AB), ketjen black, furnace black, and channel black.

15. The method according to claim 3 , wherein
the composite oxide of the positive electrode active material is LiNi 1/2 Mn 3/2 O 4 .

16. The method according to claim 3 , wherein
the manganese oxide attached to the carbon material of the conductive additive is selected from the group consisting of manganese(IV) oxide (MnO 2 ), manganese(III) oxide (Mn 2 O 3 ), and manganese(II,III) oxide (Mn 3 O 4 ).

17. The method according to claim 3 , wherein
the one of a permanganate and a manganate is a permanganate and is potassium permanganate (KMnO 4 ).

18. The method according to claim 3 , wherein
an atomic ratio of manganese to carbon in the conductive additive is from 0.05 to 0.10.

19. The method according to claim 16 , wherein
an atomic ratio of manganese to carbon in the conductive additive is from 0.05 to 0.10.

Assignees

• Toyota Motor Co Ltd

Inventors

• Akiyama Naohisa
• Kitayoshi Masanori
• Miura Takashi
• Hori Yukiko
• Ueda Masashi

Classifications

• H01M4/623

  fluorinated polymers · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M10/446

  Initial charging measures · CPC title

• H01M4/1391

  of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M10/4235

  Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence) · CPC title