KR-20260065061-A - ZERO GAP BASED AMMONIA ELECTROLYSIS CELLS AND SYSTEMS

KR20260065061AKR 20260065061 AKR20260065061 AKR 20260065061AKR-20260065061-A

Abstract

A zero-gap based alkaline ammonia electrolytic cell according to one embodiment of the present invention comprises an end plate; a current collector plate; a bipolar plate; a porous transmission layer; an electrode; and a diaphragm, wherein the diaphragm may comprise a porous ceramic composite in which ZrO2 particles are contained in a polymer binder. Accordingly, according to the present invention, a zero-gap alkaline ammonia electrolytic cell utilizing a porous ceramic composite in which ZrO2 particles are contained in a polymer binder can be provided, which has significantly superior durability and maximum current density performance compared to conventional ion exchange membrane-based cells or H-type cells.

Inventors

김용태
신해용
정상문
임영진

Assignees

포항공과대학교 산학협력단

Dates

Publication Date: 20260508
Application Date: 20241031

Claims (9)

A zero-gap based alkaline ammonia electrolytic cell comprising an end plate; a current collector plate; a bipolar plate; a porous transmission layer; an electrode; and a diaphragm, wherein the diaphragm comprises a porous ceramic composite in which ZrO2 is contained in a polymer binder.
In paragraph 1, The fastening pressure of the above electrolytic cell is 80 kgf/ cm² to 120 kgf/ cm² , Zero-gap based alkaline ammonia electrolytic cell.
In paragraph 2, The fastening pressure of the above electrolytic cell is 100 kgf/ cm² , Zero-gap based alkaline ammonia electrolytic cell.
In paragraph 1, The flow rate of the electrolyte supplied to the electrolytic cell is 150 cc/min to 250 cc/min, Zero-gap based alkaline ammonia electrolytic cell.
In paragraph 1, Among the electrolytes supplied to the above electrolytic cell, the concentration of KOH is 6 M or higher, Zero-gap based alkaline ammonia electrolytic cell.
In paragraph 1, The concentration of NH₃ in the electrolyte supplied to the above electrolytic cell is 0.5 M or less, Zero-gap based alkaline ammonia electrolytic cell.
In paragraph 1, The operating temperature of the above electrolytic cell is 66℃ or higher Zero-gap based alkaline ammonia electrolytic cell.
A zero-gap based alkaline ammonia electrolytic cell according to any one of claims 1 to 7; A peristaltic pump that supplies electrolyte to the above electrolytic cell; and A zero-gap based alkaline ammonia electrolysis system comprising a heater for heating the above electrolyte.
In paragraph 8, A zero-gap based alkaline ammonia electrolysis system characterized by having a stack structure in which two or more of the above-mentioned electrolytic cells are stacked.

Description

Zero Gap Based Ammonia Electrolytic Cells and Systems The present invention relates to an ammonia electrolytic cell and system, and more specifically, to an ammonia electrolytic cell and system that utilizes a porous ceramic composite containing ZrO2 to have superior maximum current density and durability compared to conventional anion exchange membrane-based or H-type cells. Traditionally, alkaline ammonia electrolysis systems have primarily relied on H-type cells, utilizing two electrode plates separated by a liquid alkaline electrolyte. However, this configuration limits hydrogen conversion due to high solution resistance and the impossibility of stacking cells. Recognizing these limitations, recent ammonia electrolysis research is shifting toward anion exchange membrane (AEM)-based alkaline ammonia electrolysis, which can achieve higher hydrogen production rates by minimizing the gap between electrodes (<2 mm) and stacking cells. Despite these advantages, however, AEM-based alkaline ammonia electrolysis still faces fundamental problems, such as low ionic conductivity, limited chemical stability at high pH, and susceptibility to NH3 poisoning. Traditional H-cell-based ammonia electrolytic cell systems have the disadvantage of being laboratory-scale and unable to produce large quantities of hydrogen due to the impossibility of stacking. Therefore, to address this, various cell systems were introduced, leading to the development of a zero-gap-based cell system capable of minimizing resistance between electrodes. However, existing cell systems utilize anion exchange membranes as separators; these membranes have low durability against KOH and NH₃ , and their low OH⁻ ion conductivity makes them difficult to use in high-performance, high-durability ammonia electrolytic cells. FIG. 1 is a schematic diagram of a zero-gap alkaline ammonia electrolytic cell configuration according to one embodiment of the present invention. FIG. 2 is a block diagram for driving a zero-gap alkaline ammonia electrolytic cell according to one embodiment of the present invention. FIG. 3 is a graph showing (a) an alkaline ammonia electrolytic polarization curve at various coupling pressures and (b) a maximum current density according to one embodiment of the present invention. FIG. 4 is a graph showing (a) an alkaline ammonia electrolytic polarization curve at various flow rates and (b) a maximum current density according to one embodiment of the present invention. Figure 5 shows the electrolytic polarization curves of alkaline ammonia at 1 M NH₃ and various KOH concentrations according to one embodiment of the present invention. a) and b) were measured at 50°C and 70°C, respectively. FIG. 6 is a polarization curve at 8 M KOH and various NH3 concentrations according to one embodiment of the present invention, where a) and b) were measured at 50°C and b) 70°C, respectively. FIG. 7 is a) polarization curve at various temperatures and b) Arrhenius diagram at various potentials according to one embodiment of the present invention. FIG. 8a is a schematic diagram of a zero-gap and AEM-based cell according to one embodiment of the present invention, and the figure below the dotted line shows a separator and membrane in operation. Figure 8b shows polarization curves for various cell types. Figure 8c is a comparison of current densities between different types of ammonia electrolytic cells. FIG. 8d shows the change in ion conductivity of a porous ceramic composite containing ZrO2 particles in a polymer binder and an AEM before and after a durability test according to one embodiment of the present invention. FIG. 8e shows the change in polarization curves of a porous ceramic composite containing ZrO2 particles in a polymer binder and an AEM before and after a durability test according to one embodiment of the present invention. The following description merely illustrates the principles of the invention. Therefore, those skilled in the art may invent various devices that embody the principles of the invention and are included within the concept and scope of the invention, even if they are not explicitly described or illustrated in this specification. Furthermore, all conditional terms and embodiments listed in this specification are, in principle, explicitly intended only for the purpose of understanding the concept of the invention and should be understood as not being limited to the embodiments and conditions specifically listed as such. Furthermore, in the following description, ordinal expressions such as "first," "second," etc., are intended to describe mutually equal and independent objects, and should be understood as having no meaning of main/sub or master/slave in their order. The aforementioned objectives, features, and advantages will become clearer through the following detailed description in conjunction with the attached drawings, and accordingly, a person skilled in the art to which the invention pertains will be able to easily im