Power storage device having a nitroxyl polymer in a cathode and a lithium or lithium alloy anode

Patent metadata

Field	Value
Publication number	US-9443661-B2
Application number	US-59751806-A
Country	US
Kind code	B2
Filing date	Dec 17, 2004
Priority date	Feb 16, 2004
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

An object of the present invention is to provide a power storage device with excellent cycle property, employing a cathode containing a nitroxyl polymer. To attain the object in the present invention, in the power storage device employing a cathode comprising a nitroxyl polymer, a lithium or lithium alloy anode is used as an anode active material and the cathode is in direct contact with the anode.

First claim

The invention claimed is:

1. A secondary electrochemical cell comprising a cathode and an anode,
wherein:
the cathode comprises a cathode layer comprising nitroxyl polymer, and a cathode collector;
the nitroxyl polymer has a nitroxyl cation partial structure represented by the following chemical formula (I) in oxidation state and has a nitroxyl radical partial structure represented by the following chemical formula (II) in reduction state, employing a reaction for transferring an electron between the two states represented by the following equation (B) as an electrode reaction of the cathode:

 wherein
the anode comprises a lithium or lithium alloy as an anode active material;
the cathode layer is impregnated with an electrolyte having an electrolyte solution comprising a solvent and an electrolyte salt dissolved in the solvent the cathode layer being in direct contact with a surface of the anode; and
the nitroxyl polymer is applied onto the cathode collector and is in direct contact with the surface of the anode.

2. The secondary electrochemical cell according to claim 1 , wherein a lithium-tin alloy or a lithium-silicon alloy is used as the anode active material.

3. The secondary electrochemical cell according to claim 1 , wherein the cathode collector comprises an aluminum plate and a conductive auxiliary layer comprising carbon as a main component, and the conductive auxiliary layer formed and integrated on the aluminum plate.

4. The secondary electrochemical cell according to claim 1 , wherein the cathode collector comprises a carbon paper.

5. The secondary electrochemical cell according to claim 1 , wherein the nitroxyl polymer is a polymer compound having a cyclic nitroxyl structure represented by the following chemical formula (5) in oxidation state:

wherein each of R 1 to R 4 independently represents an alkyl group, and X represents a divalent group so that the chemical formula (5) forms a 5- to 7-membered ring, while X constitutes a part of a side chain or a main chain of the polymer.

6. The secondary electrochemical cell according to claim 5 , wherein the nitroxyl polymer is a polymer compound having a side chain containing a residue which removes at least one hydrogen atom bonded to an element forming at least one cyclic nitroxyl structure selected from the group consisting of a 2,2,6,6-tetramethylpiperidinoxyl cation represented by chemical formula (6), a 2,2,5,5-tetramethylpyrrolidinoxyl cation represented by chemical formula (7) and a 2,2,5,5-tetramethylpyrrolinoxyl cation represented by chemical formula (8)'

7. The secondary electrochemical cell according to claim 1 , wherein the cathode layer further comprises an electro-conductivity imparting material, and a content of the electro-conductivity imparting material in the cathode layer is 50% by weight or less.

8. The secondary electrochemical cell according to claim 1 , wherein the cathode layer consists essentially of the nitroxyl polymer.

9. The secondary electrochemical cell according to claim 1 , wherein the cathode layer consists of the nitroxyl polymer and a polymer electrolyte.

10. The secondary electrochemical cell according to claim 1 , wherein the secondary electrochemical cell is a coin-type cell.

11. The secondary electrochemical cell according to claim 1 , wherein the solvent comprises a carbonate solvent.

12. The secondary electrochemical cell according to claim 1 , wherein the cathode layer consists of the nitroxyl polymer, a polymer electrolyte and a binder.

Assignees

• Nakahara Kentaro
• Iriyama Jiro
• Iwasa Shigeyuki
• Suguro Masahiro
• Satoh Masaharu
• Nec Corp

Inventors

• Nakahara Kentaro
• Iriyama Jiro
• Iwasa Shigeyuki
• Suguro Masahiro
• Satoh Masaharu

Classifications

• H01M4/386 Primary

  Silicon or alloys based on silicon · CPC title

• H01G11/62

  characterised by the solute, e.g. salts, anions or cations therein · CPC title

• H01G11/50

  specially adapted for lithium-ion capacitors, e.g. for lithium-doping or for intercalation · CPC title

• H01G11/06

  with one of the electrodes allowing ions to be reversibly doped thereinto, e.g. lithium ion capacitors [LIC] · CPC title

• Y02E60/13

  Energy storage using capacitors · CPC title