Secondary battery, battery pack, and vehicle

Patent metadata

Field	Value
Publication number	US-2018269537-A1
Application number	US-201715692334-A
Country	US
Kind code	A1
Filing date	Aug 31, 2017
Priority date	Mar 17, 2017
Publication date	Sep 20, 2018
Grant date	—

Abstract

According to one embodiment, a secondary battery is provided. The secondary battery includes a positive electrode, a negative electrode, and an aqueous electrolyte. The aqueous electrolyte includes a first aqueous electrolyte and a second aqueous electrolyte. The first aqueous electrolyte is in contact with at least part of the positive electrode and contains lithium ions. The second aqueous electrolyte is in contact with at least part of the negative electrode and contains lithium ions. The concentration of lithium ions contained in the second aqueous electrolyte is higher than the concentration of lithium ions contained in the first aqueous electrolyte.

First claim

What is claimed is:

1 . A secondary battery comprising a positive electrode, a negative electrode, and an aqueous electrolyte,
wherein the aqueous electrolyte includes a first aqueous electrolyte and a second aqueous electrolyte, the first aqueous electrolyte is in contact with at least part of the positive electrode and contains lithium ions, the second aqueous electrolyte is in contact with at least part of the negative electrode and contains lithium ions, and a concentration of the lithium ions contained in the second aqueous electrolyte is higher than the concentration of the lithium ions contained in the first aqueous electrolyte.

2 . The secondary battery according to claim 1 ,
wherein the first aqueous electrolyte is in contact with only the positive electrode among the negative electrode and the positive electrode, and the second aqueous electrolyte is in contact with only the negative electrode among the negative electrode and the positive electrode.

3 . The secondary battery according to claim 1 ,
wherein a concentration C 1 of the lithium ions contained in the first aqueous electrolyte falls within a range from 1 mol/L to less than 5 mol/L, and a concentration C 2 of the lithium ions contained in the second aqueous electrolyte falls within a range from 5 mol/L to 12 mol/L.

4 . The secondary battery according to claim 3 ,
wherein a ratio C 2 /C 1 of the concentration C 2 of the lithium ions contained in the second aqueous electrolyte to the concentration C 1 of the lithium ions contained in the first aqueous electrolyte falls within a range from 2 to 11.

5 . The secondary battery according to claim 1 ,
wherein at least one of the first aqueous electrolyte and the second aqueous electrolyte is a gel aqueous electrolyte.

6 . The secondary battery according to claim 1 , further comprising a partition configured to separate the first aqueous electrolyte and the second aqueous electrolyte,
wherein the partition is an ion exchange membrane or a solid electrolyte.

7 . The secondary battery according to claim 1 ,
wherein the first aqueous electrolyte contains a first anionic species, the second aqueous electrolyte contains a second anionic species, and the first anionic species and the second anionic species are different from each other.

8 . The secondary battery according to claim 7 ,
wherein the first anionic species includes sulfate ions, and the second anionic species includes at least one species selected from the group consisting of bis(trifluoromethanesulfonyl)imide ions and bis(fluorosulfonyl)imide ions.

9 . A battery pack comprising the secondary battery according to claim 1 .

10 . The battery pack according to claim 9 , further comprising an external power distribution terminal and a protective circuit.

11 . The battery pack according to claim 9 , further comprising plural of the secondary batteries,
wherein the secondary batteries are electrically connected in series, in parallel, or in a combination of series connection and parallel connection.

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

13 . The vehicle according to claim 12 , which comprises a mechanism configured to convert kinetic energy of the vehicle into regenerative energy.

Assignees

• Toshiba Kk

Inventors

• Yoshima Kazuomi
• Matsuno Shinsuke
• Takami Norio

Classifications

• H01M10/4257 Primary

  Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries · CPC title

• H01M10/36 Primary

  Accumulators not provided for in groups H01M10/05-H01M10/34 · CPC title

• H01M10/0585

  of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators · CPC title

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M2300/0085

  Immobilising or gelification of electrolyte · CPC title