LAMINATED LITHIUM-SULPHUR CELL

• US 20160204473A1
• Filed: 08/13/2014
• Published: 07/14/2016
• Est. Priority Date: 08/15/2013
• Status: Active Grant

• Current Assignee: Gelion Technologies Pty Ltd
• Original Assignee: OXIS Energy Limited (Johnson Matthey PLC)
• Inventors: Lindstrom, Ove, Ivanova, Mariya
• Granted Patent: US 10,020,533 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0583 of accumulators with folded construction elements except wound ones, i.e. folded positive or negative electrodes or separators, e.g. with "Z"-shaped electrodes or separators
• CPC Class Codes: H01M 4/382 Lithium H01M4/405 takes precedence
• CPC Class Codes: H01M 4/405 Alloys based on lithium
• CPC Class Codes: H01M 4/5815 Sulfides
• CPC Class Codes: H01M 50/46 Separators, membranes or diaphragms characterised by their combination with electrodes
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A lithium-sulphur electrochemical cell comprising a laminate comprising: a lithium anode comprising a layer of lithium metal foil or lithium metal alloy foil; a cathode comprising an active sulphur material; a porous separator disposed between the lithium anode and the cathode; and an electrolyte; wherein: the laminate is folded in a zigzag configuration; and the cathode is offset relative to the lithium anode in the laminate, such that the cathode is accessible from one side of the laminate and the lithium anode is accessible from an opposite side of the laminate.

Claims

1. A lithium-sulphur electrochemical cell comprising a laminate comprising:

a lithium anode comprising a layer of lithium metal foil or lithium metal alloy foil;

a cathode comprising an active sulphur material;

a porous separator disposed between the lithium anode and the cathode; and

an electrolyte;

wherein;

the laminate is folded in a zigzag configuration; and

the cathode is offset relative to the lithium anode in the laminate, such that the cathode is accessible from one side of the laminate and the lithium anode is accessible from an opposite side of the laminate.

2. A cell as claimed in claim 1, wherein the cathode is offset relative to the lithium anode in a direction perpendicular to the longitudinal axis of the laminate.

3. A cell as claimed in claim 1 or 2, wherein the layer of lithium metal foil or lithium alloy foil is absent at the ends of the folded laminate.

4. A cell as claimed in any one of the preceding claims, wherein the cathode comprises a layer comprising a mixture of active sulphur material and electroconductive material deposited on a current collector.

5. A cell as claimed in claim 4, wherein the current collector is formed of metal foil.

6. A cell as claimed in any one of the preceding claims, which further comprises a further lithium anode and a further porous separator, wherein

the cathode is disposed between the lithium anodes and a porous separator is disposed between the cathode and each lithium anode, and

the lithium anodes are disposed such that both lithium anodes are accessible from the opposite side or end of the folded laminate.

7. A method of manufacturing a lithium-sulphur cell, said method comprising:

forming a laminate of i) a lithium anode comprising a layer of lithium metal or lithium metal alloy foil, ii) a porous separator;

iii) electrolyte; and

iv) a cathode comprising an active sulphur material, whereby the separator is disposed between the lithium anode and the cathode and the cathode is offset relative to the lithium anode in the laminate, such that the cathode is accessible from one side of the laminate and the lithium anode is accessible from an opposite side of the laminate; and

folding the laminate in a zigzag configuration.

8. A method as claimed in claim 7, wherein the laminate further comprises a further lithium anode and a further porous separator containing electrolyte, wherein

the cathode is disposed between the lithium anodes and a porous separator is disposed between the cathode and each lithium anode, and

the lithium anodes are disposed such that both lithium anodes are accessible from the opposite side of the laminate.

9. A method as claimed in claim 7 or 8, which comprises:

providing the cathode comprising an active sulphur material as a flow of web material;

applying electrolyte to the cathode;

laminating the porous separator onto the cathode as a flow of web material; and

laminating the lithium anode onto the separator as a flow of web material to form the laminate as a flow of web material, whereby the web of the lithium anode material and web of cathode material are off set relative to one another in a direction perpendicular to the direction of flow;

wherein the electrolyte is applied to the cathode before or after the porous separator is laminated onto the cathode.

10. A method as claimed in claim 9, which further comprises folding the web of laminate material in a zigzag configuration and cutting the laminate material to a predetermined length.

11. A method as claimed in any one of claims 9 to 10, wherein the web material of the anode comprises a discontinuous layer of lithium metal foil or lithium alloy foil, and wherein the laminate is cut along the discontinuities of the layer.

12. A method as claimed in claim 11, wherein the lithium anode is initially provided as an anode precursor comprising a layer of lithium metal foil or lithium alloy foil supported on a substrate and wherein, the precursor is provided as a web of material and, at regular intervals along the length of the web material, sections of the layer of lithium metal foil or lithium alloy foil are removed from the substrate.

14. A method as claimed in claim 12 or 13, wherein the sections are removed by passing the precursor between a pair of rollers, one of which is provided with cutters configured to cut or scrape sections of the layer of lithium metal or lithium alloy from the substrate.

15. A method as claimed in any one of claims 12 to 14, which further comprises removing the substrate of the anode precursor from the laminate.

13. A method as claimed in claim 13, wherein the sections are removed before the lithium anode is laminated onto the separator.