Two-step method for fabricating a hierarchical nanoporous metal structure

Patent metadata

Field	Value
Publication number	US-2024218549-A1
Application number	US-202318398214-A
Country	US
Kind code	A1
Filing date	Dec 28, 2023
Priority date	Dec 30, 2022
Publication date	Jul 4, 2024
Grant date	—

Abstract

The present invention provides a two-step method to fabricate a nanoporous metal surface layer supported on the macroscopic metallic foam. The porous structure has an average ligament/pore size from dozens to a few hundred nanometers. The prepared monolithic electrode can simultaneously maintain a rigid metallic skeleton for good mechanical integrity, electrical conductive and hydraulic permeability while the porous layer increase surface area and therefore showcases good performance in the flow-cell, such as Zn-Iodide flow cells and electrochemical organic synthesis.

First claim

What is claimed is:

1 . A two-step method for fabricating a hierarchical nanoporous metal structure, comprising the following steps:
forming a sacrificial material on a metallic structure, with the intention of forming a precursor alloy through annealing; and dealloying the precursor alloy and the sacrificial material is removed to create a desired hierarchical nanoporous structure.

2 . The method of claim 1 , wherein the metallic structure has open pores larger than 1 micron.

3 . The method of claim 2 , wherein the metallic structure comprises open-cell a metallic foam, a metallic foil, or a metallic mesh.

4 . The method of claim 3 , wherein the metallic structure is made of copper, nickel, silver, tin, or a combination thereof.

5 . The method of claim 1 , wherein the sacrificial material comprises zinc, tin, and an element forms a homogeneous alloy precursor with the metal of the metallic structure.

6 . A two-step method for fabricating a hierarchical nanoporous metal structure, comprising the following steps:
forming a thin layer of insoluble compounds on a metallic structure and utilizing the insoluble compounds as a precursor; and removing one or more anionic components from the insoluble compound via a reduction process to create a desired hierarchical nanoporous structure.

7 . The method of claim 6 , wherein the metallic structure has open pores larger than 1 micron.

8 . The method of claim 7 , wherein the metallic structure comprises open-cell a metallic foam, a metallic foil, or a metallic mesh.

9 . The method of claim 8 , wherein the metallic structure is made of copper, nickel, silver, tin, or a combination thereof.

10 . The method of claim 6 , wherein the insoluble compound is selected from a metal oxide, a sulfide, or a hydroxide.

11 . A Zn-Iodide redox flow cell, comprising:
a anode comprising at least one hierarchical nanoporous metal structure; at least one counter electrode as a cathode; a separator positioned between the cathode and the anode; an electrolyte consisting of a catholyte and an anolyte; and a two-channel peristaltic pump for propelling the electrolytes.

12 . The Zn-Iodide redox flow cell of claim 11 , wherein the cathode comprises a layer of nanoporous metal on top of a metallic structure of with open pores larger than one micron.

13 . The Zn-Iodide redox flow cell of claim 11 , wherein the hierarchical nanoporous metal structure possesses an average ligament size or a pore size of 50 nm to 200 nm.

14 . The Zn-Iodide redox flow cell of claim 11 , wherein the at least one counter electrode comprises carbonous electrode or Pt foil electrode.

15 . The Zn-Iodide redox flow cell of claim 11 , wherein the Zn-Iodide redox flow cell further comprises at least one electrolyte tank for holding the electrolyte.

16 . The Zn-Iodide redox flow cell of claim 11 , wherein the electrolyte comprises a neutral based solution.

17 . The Zn-Iodide redox flow cell of claim 11 , wherein the Zn-Iodide redox flow cell exhibits a coulombic efficiency of at least 97%, an energy efficiency of at least 75%, and a capability to operate through more than 100 cycles.

18 . The Zn-Iodide redox flow cell of claim 11 , wherein the Zn-Iodide redox flow cell exhibits an energy efficiency of at least 80% at the current density in a range of 20 mA cm −2 to 40 mA cm −2 .

Assignees

• Univ Hong Kong Science & Tech

Inventors

• Chen Qing
• Li Yang
• Sang Yingji

Classifications

• C22F1/08

  of copper or alloys based thereon · CPC title

• C25B11/031

  Porous electrodes · CPC title

• C25D5/48

  After-treatment of electroplated surfaces · CPC title

• C25D9/04

  with inorganic materials · CPC title

• C22C3/005

  Separation of the constituents of alloys · CPC title