NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

• US 20130337305A1
• Filed: 03/03/2011
• Published: 12/19/2013
• Est. Priority Date: 03/03/2011
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Nagai, Hiroki, Morita, Masahiro, Iwao, Takashi, Okada, Yukihiro
• Granted Patent: US 9,997,743 B2
• Time in Patent Office: Days
• US Class Current: 429/94
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0566 Liquid materials
• CPC Class Codes: H01M 10/0568 characterised by the solutes
• CPC Class Codes: H01M 10/0569 characterised by the solvents
• CPC Class Codes: H01M 10/0587 of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: H01M 50/103 prismatic or rectangular H01M50/109, H01M50/11 take precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

It is an object of the present invention to provide a nonaqueous electrolyte secondary battery with superior high-temperature charge-discharge cycle characteristics as well as superior low-temperature high-rate charge-discharge cycle characteristics. A nonaqueous electrolyte secondary battery 100 according to the present invention has an electrode body 80 which includes a positive electrode and a negative electrode, and a battery case 50 which houses the electrode body 80 together with a nonaqueous electrolyte, wherein among the nonaqueous electrolyte housed in the battery case 50, an electrolyte amount ratio (A/B) between a surplus electrolyte amount (A) that exists outside the electrode body 80 and an intra-electrode body electrolyte amount (B) impregnating the electrode body 80 ranges from 0.05 to 0.2, and DBP absorption of a positive electrode active material that constitutes the positive electrode is equal to or higher than 30 (ml/100 g).

Claims

1. A nonaqueous electrolyte secondary battery comprising:

an electrode body which includes a positive electrode and a negative electrode; and

a battery case which houses the electrode body together with a nonaqueous electrolyte, wherein

among the nonaqueous electrolyte housed in the battery case, an electrolyte amount ratio (NB) between a surplus electrolyte amount (A) that exists outside the electrode body and an intra-electrode body electrolyte amount (B) impregnating the electrode body ranges from 0.05 to 0.2, and

DBP absorption of a positive electrode active material that constitutes the positive electrode is equal to or higher than 30 (ml/100 g).

2. The nonaqueous electrolyte secondary battery according to claim 1, wherein the DBP absorption of the positive electrode active material is equal to or lower than 50 (ml/100 g).

3. The nonaqueous electrolyte secondary battery according to claim 1, wherein the electrolyte amount ratio (A/B) ranges from 0.068 to 0.19.

4. The nonaqueous electrolyte secondary battery according to claim 1, wherein the nonaqueous electrolyte is prepared by dissolving 0.7 to 1.6 mol/L of a supporting electrolyte selected from among LiPF₆, LiBF₄, LiClO₄, and LiAsF₆ in a mixed solvent constituted by a cyclic carbonate and a chain carbonate.

5. The nonaqueous electrolyte secondary battery according to claim 1, wherein

the positive electrode active material includes

a secondary particle formed by an aggregation of a plurality of primary particles of a lithium transition metal oxide, a hollow portion formed in the secondary particle, and a through hole that penetrates the secondary particle so as to connect the hollow portion to the outside.

6. The nonaqueous electrolyte secondary battery according to claim 5, wherein the positive electrode active material has an average hardness equal to or greater than 0.5 MPa as obtained by dynamic hardness measurement under conditions of a loading speed ranging from 0.5 mN/sec to 3 mN/sec using a flat diamond indenter having a diameter of 50 μ

m.

7. The nonaqueous electrolyte secondary battery according to claim 5, wherein the through hole has an average opening width equal to or greater than 0.01 μ

m.

8. The nonaqueous electrolyte secondary battery according to claim 5, wherein the through hole has an average opening width equal to or less than 2.0 μ

m.

9. The nonaqueous electrolyte secondary battery claim 1, wherein the positive electrode active material is a lithium transition metal oxide which has a layered structure and which contains nickel as a structural element thereof.

10. The nonaqueous electrolyte secondary battery according to claim 1, wherein the positive electrode active material is a lithium transition metal oxide which has a layered structure and which contains nickel, cobalt, and manganese as structural elements thereof.

11. The nonaqueous electrolyte secondary battery according to claim 1, wherein

the positive electrode is a sheet-shaped positive electrode constructed by adding a positive electrode active material layer onto a sheet-shaped positive electrode current collector,

the negative electrode is a sheet-shaped negative electrode constructed by adding a negative electrode active material layer onto a sheet-shaped negative electrode current collector, and

the electrode body is a wound electrode body constructed by winding the sheet-shaped positive electrode and the sheet-shaped negative electrode with a separator therebetween.

12. The nonaqueous electrolyte secondary battery according to claim 1, used in charge-discharge cycles including high-rate charge and discharge at 10 C or higher.

13. A vehicle-driving nonaqueous electrolyte secondary battery constituted by the nonaqueous electrolyte secondary battery according to claim 1.