Anode for an electrochemical cell

Patent metadata

Field	Value
Publication number	US-11664491-B2
Application number	US-201716330730-A
Country	US
Kind code	B2
Filing date	Sep 5, 2017
Priority date	Sep 6, 2016
Publication date	May 30, 2023
Grant date	May 30, 2023

Abstract

An anode for an electrochemical cell comprises a lithium metal or lithium metal alloy, and a polymer coating deposited on the lithium metal or lithium metal alloy. The polymer coating is doped with lithium ions and comprises a polyisocyanurate material. The polyisocyanurate material contains ether- and/or silicone-containing further groups. The ether-containing group is a polyether, and/or wherein the silicone-containing group is a siloxane group.

First claim

The invention claimed is:

1. An anode for an electrochemical cell, the anode comprising:
a lithium metal or lithium metal alloy, and
a polymer coating deposited on the lithium metal or lithium metal alloy,
wherein the polymer coating is doped with lithium ions and comprises a polyisocyanurate material,
wherein the polyisocyanurate material contains ether- and/or silicone-containing further groups, and
wherein the ether-containing group is a polyether and/or wherein the silicone-containing group is a siloxane group.

2. The anode as claimed in claim 1 , wherein the polymer coating further includes an inorganic filler.

3. The anode as claimed in claim 2 , wherein the filler comprises silica or clay nanoparticles.

4. The anode as claimed in claim 1 , wherein the polymer coating comprises at least 5 weight % lithium ions.

5. A lithium-sulphur cell comprising:
an anode as claimed in claim 1 ,
a cathode comprising an electroconductive material and an electroactive material comprising sulphur, and
an electrolyte.

6. The anode as claimed in claim 1 , wherein the polyether is a polyalkyleneoxide-monoalkylether.

7. The anode as claimed in claim 1 , wherein the siloxane group is a trialkoxysilane group.

8. A method of forming a coating on the anode of the electrochemical cell of claim 1 , said method comprising the steps of:
a) contacting an anode formed of lithium metal or lithium metal alloy with a coating composition, wherein the coating composition is in form of a dispersion or a solution and contains a polymer precursor comprising isocyanate groups, a lithium metal salt and a solvent, and
b) trimerising the polymer precursor as a coating on the anode, wherein at least 50 mol % of the isocyanate groups of the polymer precursor form structures selected from the group consisting of isocyanurate, uretdione-, allophanate-, and iminooxadiazinedione structures.

9. The method as claimed in claim 8 , wherein the polymer precursor comprises oligomeric polyisocyanate, and wherein the oligomeric polyisocyanate is trimerised as the coating on the anode, wherein at least 50 mol % of the isocyanate groups comprised by the oligomeric polyisocyanate form structures selected from the group consisting of isocyanurate, uretdione-, allophanate-, and iminooxadiazinedione structures.

10. The method as claimed in claim 8 , wherein the dispersion or solution further includes inorganic filler(s).

11. The method as claimed in claim 9 , wherein the oligomeric polyisocyanate is an oligomer of a monomeric diisocyanate.

12. The method as claimed in claim 11 , wherein the oligomeric polyisocyanate is an oligomer of hexamethylene diisocyanate.

13. The method as claimed in claim 12 , wherein the oligomeric polyisocyanate comprises monomer units formed from a trimer of hexamethylene diisocyanate.

14. The method as claimed in claim 9 , wherein at least some of the NCO groups in the oligomeric polyisocyanate are capped with ether- and/or silicon-containing groups.

15. The method as claimed in claim 14 , wherein the ether-containing group is a polyether, in particular a polyalkyleneoxide-monoalkylether, and/or wherein the silicone-containing group is a siloxane group, in particular a trialkoxysilane group.

16. The method as claimed in claim 8 , wherein the coating composition comprises a trimerisation catalyst, in particular an alkali metal acetate and a crown ether.

17. The method as claimed in claim 16 , wherein the trimerisation step is carried out at a temperature of 60-150° C.

Assignees

• Oxis Energy Ltd
• Covestro Deutschland Ag
• Johnson Matthey Plc

Inventors

• Klimmasch Thomas
• Weikard Jan
• Laas Hans-Josef
• Köcher Jürgen
• Ainsworth David
• Rowlands Stephen
• Kreis Justyna Katarzyna
• Lawes Stephen
• Desilani Sebastien

Classifications

• H01M4/62

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M4/38

  of elements or alloys · CPC title

• H01M4/382

  Lithium (H01M4/405 takes precedence) · CPC title

• H01M10/052

  Li-accumulators · CPC title