Electrode for nonaqueous electrolyte secondary battery, nonaqueous electrolyte secondary battery, battery pack, and vehicle

• US 10,511,026 B2
• Filed: 09/02/2016
• Issued: 12/17/2019
• Est. Priority Date: 03/24/2014
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Fukasawa, Takayuki, Essaki, Kenji, Morita, Tomokazu, Kuboki, Takashi
• Primary Examiner(s): Weiner, Laura
• Application Number:
  US15/255,720
• Publication Number:
  US 20160372753A1
• Time in Patent Office: 1,201 Days
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 2004/027 Negative electrodes
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 2300/0037 Mixture of solvents
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/362 Composites
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 4/483 for non-aqueous cells H01M4/485 takes precedence
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: H01M 4/624 Electric conductive fillers
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A negative electrode active material of an embodiment for a nonaqueous electrolyte battery includes silicon or silicon oxide including silicon inside, a carbonaceous substance containing the silicon or the silicon oxide including silicon inside, and a phase including a silicate compound and a conductive assistant, the phase being interposed between the silicon or the silicon oxide including silicon inside and the carbonaceous substance. The silicate compound is a complexed oxide including an oxide including at least one element selected from the group consisting of; an alkaline earth element, a transition metal element, and a rare-earth element and a silicon oxide.

Claims

1. A negative electrode active material for a nonaqueous electrolyte battery, comprising:

a particle of silicon oxide enveloping particles of silicon;

a carbonaceous substance covering the particle of silicon oxide enveloping particles of silicon; and

a phase comprising a silicate compound mixed with a conductive assistant, the phase being interposed between the particle of silicon oxide enveloping particles of silicon and the carbonaceous substance,

wherein

the silicate compound is at least one compound selected from the group consisting of MgSiO₃, Mg₂SiO₄, TiSiO₄, Mn₂SiO₄, FeSiO₃, Fe₂SiO₄, Co₂SiO₄, Ni₂SiO₄, Al₂SiO₅, ZrSiO₄, Y₂SiO₅, and Y₂Si₂O₇.

2. The active material according to claim 1,

wherein the particle of silicon oxide enveloping the particles of silicon account for from 20 mass % or more to 75 mass % or less when mass of the active material is defined as 100 mass %.

3. The active material according to claim 1,

wherein the conductive assistant includes at least one material selected from the group consisting of graphite, hard carbon, soft carbon, amorphous carbon, acetylene black, and silicon carbide.

4. The active material according to claim 1,

wherein a mass mixing ratio between the silicate compound and the conductive assistant is between 10:

90 and 90;

10.

5. The negative electrode active material according to claim 1, wherein an average primary grain diameter of the active material is from 0.1 μ

m to 50 μ

m.

6. A negative electrode for a nonaqueous electrolyte secondary battery, comprising:

a collector; and

an electrode mixture layer on the collector, comprising the negative electrode active material according to claim 1, and further comprising a conductive material and a binder.

7. The negative electrode according to claim 6 wherein the conductive material is selected from the group consisting of acetylene black, carbon black and graphite.

8. A nonaqueous electrolyte secondary battery comprising:

an exterior material;

a positive electrode housed in the exterior material;

a negative electrode spatially apart from the positive electrode, the negative electrode being housed in the exterior material with a separator interposed between the negative electrode and the positive electrode, the negative electrode comprising the negative electrode according to claim 6; and

a nonaqueous electrolyte filled in the exterior material.

9. A battery pack comprising the nonaqueous electrolyte secondary battery according to claim 8.

10. A vehicle comprising the battery pack according to claim 9.