Negative electrode for secondary battery, secondary battery, battery pack, electric vehicle, power storage system, power tool, and electronic device

Patent metadata

Field	Value
Publication number	US-2018323434-A1
Application number	US-201816039482-A
Country	US
Kind code	A1
Filing date	Jul 19, 2018
Priority date	Jan 29, 2016
Publication date	Nov 8, 2018
Grant date	—

Abstract

The secondary battery includes an electrolytic solution, a positive electrode and a negative electrode, and the negative electrode includes a plurality of particulate negative electrode active materials, a first negative electrode binder, and a plurality of second negative electrode binders with an average particle size smaller than the plurality of particulate negative electrode active materials. The plurality of particulate negative electrode active materials have an average particle size of 5 μm or more and 30 μm or less. The first negative electrode binder includes one or both of a styrene butadiene rubber and a derivative thereof. The plurality of second negative electrode binders include one or both of a polyvinylidene fluoride and a derivative thereof, and the plurality of second negative electrode binders have an average particle size of 0.1 μm or more and 10 μm or less.

First claim

1 . A secondary battery comprising:
a positive electrode,
a negative electrode, and
an electrolytic solution,
wherein the negative electrode includes a plurality of particulate negative electrode active materials, a first negative electrode binder, and a plurality of second negative electrode binders with an average particle size smaller than the plurality of particulate negative electrode active materials,
wherein the plurality of particulate negative electrode active materials have an average particle size of 5 μm or more and 30 μm or less,
wherein the first negative electrode binder includes one or both of styrene butadiene rubber and a derivative of styrene butadiene,
wherein the plurality of second negative electrode binders include one or both of polyvinylidene fluoride and a derivative of polyvinylidene fluoride, and
wherein the plurality of second negative electrode binders have an average particle size of 0.1 μm or more and 10 μm or less.

2 . The secondary battery according to claim 1 , wherein at least some of the plurality of second negative electrode binders are provided in a gap between the plurality of particulate negative electrode active materials.

3 . The secondary battery according to claim 1 , wherein a first content 100−X−Y (wt %) of the plurality of particulate negative electrode active materials, a second content X (wt %) of the first negative electrode binder, and a third content Y (wt %) of the plurality of second negative electrode binders satisfy conditions of: X=0.5 wt % or more and 5 wt % or less and Y=0.5 wt % or more and 5 wt % or less.

4 . The secondary battery according to claim 1 , wherein
the negative electrode includes a negative electrode active material layer including the plurality of particulate negative electrode active materials, the first negative electrode binder, and the plurality of second negative electrode binders, and the negative electrode active material layer has a thickness of 30 μm or more and 250 μm or less.

5 . The secondary battery according to claim 1 , wherein the plurality of particulate negative electrode active materials includes a carbon material.

6 . The secondary battery according to claim 1 , wherein the plurality of particulate negative electrode active materials includes a material including silicon.

7 . The secondary battery according to claim 1 , wherein
the secondary battery further includes a film-shaped exterior member, and the positive electrode, the negative electrode, and the electrolytic solution are provided inside the film-shaped exterior member.

8 . The secondary battery according to claim 1 , wherein the secondary battery includes a lithium ion secondary battery.

9 . The secondary battery according to claim 1 , wherein the plurality of second negative electrode binders are particulate.

10 . A negative electrode, comprising:
a plurality of particulate negative electrode active materials, a first negative electrode binder, and a plurality of second negative electrode binders having an average particle size smaller than the plurality of particulate negative electrode active materials, wherein the plurality of particulate negative electrode active materials have an average particle size of 5 μm or more and 30 μm or less, wherein the first negative electrode binder includes one or both of styrene butadiene rubber and a derivative of styrene butadiene, wherein the plurality of second negative electrode binders include one or both of polyvinylidene fluoride and a derivative of polyvinylidene fluoride, and wherein the plurality of second negative electrode binders have an average particle size of 0.1 μm or more and 10 μm or less.

11 . A battery pack comprising:
a secondary battery; a controller configured to control an operation of the secondary battery; and a switch configured to switch an operation of the secondary battery in accordance with an instruction from the controller, wherein the secondary battery includes an electrolytic solution, a positive electrode and a negative electrode, wherein the negative electrode includes a plurality of particulate negative electrode active materials, a first negative electrode binder, and a plurality of second negative electrode binders with an average particle size smaller than the plurality of particulate negative electrode active materials, wherein the plurality of particulate negative electrode active materials have an average particle size of 5 μm or more and 30 μm or less, wherein the first negative electrode binder includes one or both of styrene butadiene rubber and a derivative of styrene butadiene rubber, wherein the plurality of second negative electrode binders include one or both of polyvinylidene fluoride and a derivative of polyvinylidene fluoride, and wherein the plurality of particulate second negative electrode binders have an average particle size of 0.1 μm or more and 10 μm or less.

12 . An electric vehicle comprising:
the secondary battery according to claim 1 ; a converter configured to convert electric power supplied from the secondary battery, to a driving force; a driver configured to drive in response to the driving force; and a controller configured to control an operation of the secondary battery.

13 . A power storage system comprising:
the secondary battery according to claim 1 ; one or more electric devices configured to be supplied with electric power from the secondary battery; and a controller configured to control the power supply to the electric devices from the secondary battery.

14 . A power tool comprising:
the secondary battery according to claims 1 ; and a movable part configured to be supplied with electric power from the secondary battery.

15 . An electronic device comprising the secondary battery according to claim 1 as a power supply source.

Assignees

• Murata Manufacturing Co

Inventors

• Munaoka Takatoshi
• Ihara Masayuki
• Fujita Shigeru
• Hashimoto Takuju

Classifications

• H01M50/126

  comprising three or more layers · CPC title

• H01M50/119

  Metals · CPC title

• H01M50/121

  Organic material · CPC title

• H01M4/623 Primary

  fluorinated polymers · CPC title

• H01M2/0257

  Electricity · mapped topic