Lithium-iodine electrochemical cells exhibiting low discharge impedance

Patent metadata

Field	Value
Publication number	US-10790482-B2
Application number	US-201816048984-A
Country	US
Kind code	B2
Filing date	Jul 30, 2018
Priority date	Aug 4, 2017
Publication date	Sep 29, 2020
Grant date	Sep 29, 2020

Abstract

An lithium-iodine electrochemical cell and method of making is described. The cell comprises a lithium anode and a cathode of a charge transfer complex which includes iodine and preferably polyvinylpyridine. The iodine-containing cathode is in operative contact with both the anode the cell casing serving as the cathode current collector. Preferably the casing is composed of stainless steel that has been thermally annealed at temperatures of 1,800° F. or less. The annealed stainless steel has a grain size of about ASTM 7 or finer. When the iodine-containing cathode material in liquid form is filled into the casing, it contacts the inner casing surface. The passivation layer that subsequently forms at the contact interface affects cell impedance during discharge. It is desirable to maintain the internal impedance as low as possible.

First claim

What is claimed is:

1. An electrochemical cell, comprising:
a) an open-ended casing closed by a lid, wherein the casing is 304L stainless-steel having a chromium content of from 15 wt % to 20 wt %, and wherein the casing is characterized as having been annealed at a temperature ranging from 1,750° F. to 1,800° F. so that the 304 L stainless-steel has a grain size that ranges from about ASTM 7 to about ASTM 8.5;
b) a lithium-containing anode disposed inside the casing; and
c) a cathode comprising a charge transfer complex of an organic donor component and iodine as an electron acceptor component disposed inside the casing, wherein the charge transfer complex is in operative contact with the lithium-containing anode and the casing so that the open-ended casing closed by the lid serves as a cathode current collector.

2. The electrochemical cell of claim 1 , having an impedance of about 3,000 Ohm.cm 2 , or less, at a frequency of 0.1 Hz.

3. The electrochemical cell of claim 1 , wherein iodine as the electron acceptor component of the charge transfer complex has a conductivity of greater than about 2.5×10 −4 ohm/cm.

4. The electrochemical cell of claim 1 , wherein the organic donor component of the charge transfer complex is selected from the group of pyrene, perylene, anthracene, naphthalene, erythrosine, azulene, fluorene, polyethylene, polypropylene, polystyrene, polypyrrole, polyamides and polyvinyls, phenothiazine, phenazine, 10-phenylphenophiozine, thianthrene, 10-methylthiazinc, methalyineblue, poly-2-vinyl quinoline, poly-2-vinyl pyridine, poly-4-vinyl pyridine, poly-5-vinyl-2-methyl-pyridine, and poly-N-vinyl carbazole.

5. The electrochemical cell of claim 1 , wherein an anode conductor is operatively connected to the lithium-containing anode, the anode conductor being electrically isolated from the casing by a glass-to-metal seal.

6. The electrochemical cell of claim 1 being configured to power a cardiac pacemaker.

7. An electrochemical cell, comprising:
a) a casing comprised of 304L stainless-steel having a chromium content of from 15 wt % to 20 wt %, wherein the casing is characterized as having been annealed at a temperature ranging from 1,750° F. to 1,800° F. so that the 304 L stainless-steel has a grain size that ranges from about ASTM 7 to about ASTM 8.5;
b) a lithium-containing anode disposed inside the casing; and
c) a cathode comprising a charge transfer complex of an organic donor component and iodine as an electron acceptor component disposed inside the casing, wherein the charge transfer complex is in operative contact with the lithium-containing anode and the casing so that the casing serves as a cathode current collector.

8. The electrochemical cell of claim 7 , wherein the organic donor component of the charge transfer complex is selected from the group of pyrene, perylene, anthracene, naphthalene, erythrosine, azulene, fluorene, polyethylene, polypropylene, polystyrene, polypyrrole, polyamides and polyvinyls, phenothiazine, phenazine, 10-phenylphenophiozine, thianthrene, 10-methylthiazinc, methalyineblue, poly-2-vinyl quinoline, poly-2-vinyl pyridine, poly-4-vinyl pyridine, poly-5-vinyl-2-methyl-pyridine, and poly-N-vinyl carbazole.

9. The electrochemical cell of claim 7 , having an impedance of about 3,000 Ohm.cm 2 , or less, at a frequency of 0.1 Hz.

10. A method for making a low internal impedance alkali metal-iodine electrochemical cell, comprising the steps of:
a) providing an open-ended casing of 304L, stainless-steel having a chromium content of from 15 wt % to 20 wt %;
b) annealing the casing at a temperature ranging from 1,750° F. to 1,800° F. so that the 304 L stainless-steel has a grain size that ranges from about ASTM 7 to about ASTM 8.5 or finer;
c) positioning a lithium-containing anode inside the open-ended casing;
d) closing the open end of the casing with a lid;
e) filling a charge transfer complex of an organic donor component and iodine as an electron acceptor component into the casing through a fill opening in the lid so that the charge transfer complex contacts the lithium-containing anode and the casing, wherein a passivation layer forms on an inner surface of the 304 L stainless-steel casing as a result of contact with the charge transfer complex; and
f) closing the fill opening.

11. The method of claim 10 , including providing iodine as the electron acceptor component of the charge transfer complex having a conductivity of greater than about 2.5×10 −4 ohm/cm.

12. An open-ended casing for an electrochemical cell, the casing comprising:
a) 304 L stainless-steel having a chromium content of from 15 wt % to 20 wt %, b) wherein the casing is characterized as having been annealed at a temperature ranging from 1,750° F. to 1,800° F. so that the 304 L stainless steel has a grain size that ranges from about ASTM 7 to about ASTM 8.5.

13. The method of claim 10 , including selecting the organic donor component of the charge transfer complex from the group of pyrene, perylene, anthracene, naphthalene, erythrosine, azulene, fluorene, polyethylene, polypropylene, polystyrene, polypyrrole, polyamides and polyvinyls, phenothiazine, phenazine, 10-phenylphenophiozine, thianthrene, 10-methylthiazinc, methalyineblue, poly-2-vinyl quinoline, poly-2-vinyl pyridine, poly-4-vinyl pyridine, poly-5-vinyl-2-methyl-pyridine, and poly-N-vinyl carbazole.

Assignees

• Greatbatch Ltd

Inventors

• Viyannalage Lasantha
• Ganguly Adrish
• Shah Ashish
• Panek David

Classifications

• H01M50/131

  characterised by physical properties, e.g. gas permeability, size or heat resistance · CPC title

• H01M50/119

  Metals · CPC title

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• H01M50/124 Primary

  having a layered structure · CPC title

• H01M50/191

  Inorganic material · CPC title