Lithium ion secondary battery

Patent metadata

Field	Value
Publication number	US-10608244-B2
Application number	US-201615560890-A
Country	US
Kind code	B2
Filing date	Mar 22, 2016
Priority date	Mar 24, 2015
Publication date	Mar 31, 2020
Grant date	Mar 31, 2020

Abstract

A lithium ion secondary battery having more improved cycle characteristics is provided. The present invention relates to a lithium ion secondary battery having a negative electrode comprising a graphite and a silicon oxide having a composition represented by SiOx (0<x≤2), wherein AG/AS is within a range of 0.6 or more and 1.6 or less when a particle number average aspect ratio of the graphite is defined as AG and a particle number average aspect ratio of the silicon oxide is defined as AS.

First claim

The invention claimed is:

1. A lithium ion secondary battery having a negative electrode comprising a graphite and a silicon oxide having a composition represented by SiO x (0<x≤2), wherein a particle number average aspect ratio of the graphite is defined as AG and a particle number average aspect ratio of the silicon oxide is defined as AS, wherein the AS is within a range of 1.5 to 5, the AG/AS is within a range of 0.6 to 1.6, and further wherein the silicon oxide has a diameter ranging from 1.0 μm to 15.0 μm, and an amount of the silicon oxide in the negative electrode is between 1% by mass or more and less than 10% by mass.

2. The lithium ion secondary battery according to claim 1 , wherein D 50G /D 50S is within a range of 0.6 to 5.0 when a median diameter of the graphite is defined as D 5OG and a median diameter of the silicon oxide is defined as D 50S .

3. The lithium ion secondary battery according to claim 1 , wherein the graphite has a ratio (G/D) in a range of 2.0 to 5.0, wherein the ratio (G/D) is a ratio of intensity G of a peak at 1550 to 1650 cm −1 to intensity D of a peak at 1300 to 1400 cm −1 by Raman spectroscopic analysis.

4. A vehicle comprising the lithium ion secondary battery according to claim 1 mounted thereon.

5. A method of producing a secondary battery comprising:
a step of stacking a positive electrode and a negative electrode via a separator to produce an electrode element and
a step of enclosing the electrode element and an electrolyte solution in an outer package, wherein
the negative electrode comprises a graphite and a silicon oxide having a composition represented by SiO x (0<x≤2), wherein a particle number average aspect ratio of the graphite is defined as AG and a particle number average aspect ratio of the silicon oxide is defined as AS, wherein the AS is within a range of 1.5 to 5, the AG/AS is within a range of 0.6 to 1.6, and further wherein the silicon oxide has a diameter ranging from 1.0 μm to 15.0 μm, and an amount of the silicon oxide in the negative electrode is between 1% by mass or more and less than 10% by mass.

6. The lithium ion secondary battery according to claim 1 , wherein AS is within a range of 2 or more and 5 or less.

7. The lithium ion secondary battery according to claim 1 , wherein the AG/AS is within a range of 0.8 to 1.2.

8. The lithium ion secondary battery according to claim 1 , wherein the AG/AS is within a range of 0.9 to 1.1.

9. The lithium ion secondary battery according to claim 1 , wherein the amount of the silicon oxide in the negative electrode is between 3% by mass or more and less than 10% by mass.

Assignees

• Nec Corp

Inventors

• Azami Takeshi

Classifications

• H01M4/483

  for non-aqueous cells (H01M4/485 takes precedence) · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M4/364 Primary

  as mixtures · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title