WO2007069939A2

WO2007069939A2 - Tubular element (variants) for electrochemical device batteries provided with a thin-layer solid electrolyte and a method for the production thereof

Info

Publication number: WO2007069939A2
Application number: PCT/RU2006/000676
Authority: WO
Inventors: Aleksandr Sergeevich Lipilin; Viktor Vladimirovich Ivanov; Vladimir Rudolfovich Khrustov; Sergey Nikolaevich Paranin; Aleksey Viktorovich Spirin
Original assignee: Obshchestvo S Ogranichennoy Otvetstvennost'yu 'natsionalnaya Innovatsionnaya Kompaniya 'novye Energeticheskie Proekty'
Priority date: 2005-12-16
Filing date: 2006-12-18
Publication date: 2007-06-21
Also published as: RU2310256C2; RU2005139440A; WO2007069939A3

Abstract

The inventive tubular element for electrochemical device batteries comprises a thin-layer solid electrolyte, corrugates embodied along the generatrix of a tube or differently shaped cylinder, thin interface layers which are applied to the corrugated and grooved surface of the solid electrolyte and gas-diffusion electrodes which are applied to the external and internal grooved electrolyte surfaces provided with interface layers. Said element is provided with spherical and pyramidal crowns, which are arranged along the tube generatrix, or in such a way that each row is diagonally shifted with respect to the adjacent rows. The tubular element provided with a carrying internal and/or external electrode has the internal and/or external smooth cylindrical surface and the external and/or internal surface embodied in the form of corrugations which are arranged along the generatrix thereof and shaped in the form of a wave, trapezium, triangle or spherical and pyramidal crowns arranged along the generatrix or in such a way that each row is diagonally shifted with respect to the adjacent rows.

Description

TUBULAR ELEMENT (OPTIONS) FOR BATTERIES OF ELECTROCHEMICAL DEVICES WITH A THIN LAYER

SOLID ELECTROLYTES AND METHOD FOR ITS MANUFACTURE

(i) Area of use

Group present invention relates to high temperature electrochemical devices (echoes) from a solid electrolyte, ^'such as electrochemical generators (fuel! Elements), electrolyzers, converters, pumps, etc. devices. More precisely, to the design of the element of these devices and to the method of its manufacture.

(ii) Prior Art

Known elements used in electrochemical devices, for example, high-temperature fuel cells with a solid oxide electrolyte based on zirconia, having a planar, tubular or block structure of a solid electrolyte coated with a gas diffusion anode and cathode (high-temperature gas electrolysis "MV Perfilyev, A. K. Demin, B.L. Kuzin, A.S. Lipilin, ISBN 5-02-001399-4, Moscow, Nauka, 1988, 232c). An element can be considered an element according to the patent of the Russian Federation Jtø2027258, H01M8 / 12, HIGH TEMPERATURE

ELECTROCHEMICAL GEHEPATOP ”, Somov SI, Demin AK, Lipilin A.S., Kuzin B.L., Perfilyev M.V. 1995, in which a tubular element with a supporting solid electrolyte, gas diffusion electrodes was used.

The closest analogue of the device, the prototype, the authors consider a ^“ fuel” element with a thin-layer solid oxide electrolyte based on zirconia of a tubular design, with

•and carrier cathode 'and deposited with a gas diffusion anode, with an anode and cathode chambers for supplying fuel reagents and an oxidizing agent and a current path along the generatrix (A.O. Sourtes Associates, Washington, DC, 1982, p. 154). The prototype of the method, the authors consider the well-known, traditional, powder, ceramic technology described in the monograph (high-temperature electrolysis of gases "M .. V. Perfiliev, AK Demin, B. L. Kuzin, A. S. Lipilin, ISBN 5-02 -001399-4., Moscow: Nauka, 1988, 232c), which consists in the fact that a prefabricated powder is formed into a product blank and is sintered, as a rule, in furnaces at high temperatures. Ceramic technologies are the cheapest, so it is advisable to use them in the manufacture of ceramic components of high-temperature solid oxide fuel cells.

The solid electrolyte itself, the most frequently used and more durable, based on yttrium stabilized zirconia (YSZ), and alternative ones based on cerium, galate or bismuth, is a ceramic that by its nature has rather low strength and heat resistance at high temperatures . These drawbacks are compounded by the fact that for devices with solid electrolyte, for example, YSZ, operating temperatures (700-1000 ⁰ C) are in the hot zone of solid electrolyte (i.e. they are quite sensitive ^* to mechanical loads). The zone of plastic deformation, in which mechanical loads do not cause nucleation of cracks and fractures, lies above 1300 ⁰ C, above the operating temperature. In this case, electrochemical devices (ECU) in the operating temperature range in devices with gaseous fuel and an oxidizing agent require inter-cavity gas density in the working area, do not allow cracks and local damage. One of the disadvantages of the elements of such ECUs is the low mechanical strength of the solid electrolyte, which does not allow its use as a carrier, with a thickness of less than 0.15-0.2 mm in a tubular structure. Several foreign firms in the UK, Switzerland, Japan and CTTTA use a carrier electrolyte of this thickness for planar fuel cell designs. The fuel elements of a tubular structure with such an electrolyte thickness are not known to the authors. Moreover, well-known technologies do not allow to obtain a tubular structure of a supporting electrolyte with such a wall thickness. The analog element (RF Patent N ° 2027258) had a wall thickness of tubular solid electrolyte of 0.4-0.5 mm. The prototype (A.O. Isepberg, 1982 1982 Natal CeIl Semipar Abstracts, Novumber 14-18.1982.) Has 40 microns, but there they use a cathode with a thickness of about a millimeter. Thus, the thick cell wall used in known cells with a supporting electrolyte two or more times not only significantly increases the consumption of electrolyte material, but also increases the internal resistance of the cell, thereby reducing specific characteristics. Another disadvantage is the relatively low working surface of the solid electrolyte electrode boundary. Recent studies to determine the real working area of a solid electrolyte have shown that only the area in contact with the gas diffusion electrode, which is only G-4% of the visible area, works. Activation of the electrodes by substances with mixed conductivity (CeO ₂ , Pr ₂ O ₃ ) increase the contact area to 8-10%. This suggests that about 90% of the surface of the solid electrolyte does not fulfill its main function of generating current, i.e. as if it is "superfluous", i.e. It performs the function not of a solid electrolyte, but of the hermetic separation of the anode and cathode gas spaces. The disadvantage of this technology is the impossibility of the well-known ceramic technologies used today: extrusion, slip casting into gypsum molds, hot casting into metal molds to produce tubes or test tubes with a wall thickness of less than 200 microns.

(iii) Disclosure of the invention.

An object of the invention is the design and manufacturing technology of an element devoid of the above disadvantages. The authors propose a tubular design of an element with a supporting thin-layer solid electrolyte with a supporting electrode or electrodes, structurally having increased strength, heat resistance, gas density while increasing the working surface of the boundary between the electrodes and electrolyte, which leads to improved specific characteristics, more functional use of solid electrolyte and longer life service item.

The problem is solved due to the fact that an intermediate layer of micron particles is formed at the boundary of each electrode with the electrolyte ^; as a result, the working surface of the solid electrolyte is more than doubled due to such microroughness. In addition to this, the working area is more than doubled due to the design - the solid electrolyte of the tubular element is made macro-relief (sections of solid electrolyte, macro-relief options are shown in Fig. 1-3). Such a technical the solution leads, how to increase the area of a single element

(improvement of specific characteristics), as well as an increase in strength, which on the one hand leads to an increase in heat resistance, the service life of the cell, and on the other hand allows the manufacture of a tubular cell with a thinner supporting electrolyte, which in turn also leads to an improvement in specific characteristics. The proposed design of the solid oxide ECU element can be implemented both with a supporting electrolyte with a thickness of 0.15 mm (Fig. 1-3), and with a supporting one of the electrodes (Fig. 4, 5) or supporting both electrodes (Fig. 6). A method of manufacturing such an element is based on the creation of multilayer structures with layers that differ both in composition (components of the ECM element) and in microstructure:

• -porous anode;

• -porous interface layer;

• - micro-rough layer of solid electrolyte;

• a thin layer of gas-tight solid electrolyte;

• - micro-rough layer of solid electrolyte;

• -porous interface layer;

• -porous cathode.

The implementation of the proposed element design became possible due to the combination of two technologies: film watering technology, for example, using polyvinyl butyral slips from powders of the above-mentioned components of different sizes (from nanometric to micron) and molding technology, layer bonding, for example, magnetic pulse pressing.

This application proposes the following design options for the element: 1. An element with a supporting solid submicron electrolyte, for example, YSZ, consisting of nanosized crystallites made of nanopowder, with a thickness providing sufficient strength, for example, 100-150 μm, with corrugations along a wave-forming tube or cylinder (Fig. l), or a trapezoid (Fig. 2), or a triangle (Fig. H). Thin electrodes, for example, 20-50 μm, are located on the outer and inner surfaces of the electrolyte and are applied in the usual way, for example, by burning electrode pastes, onto a pre-sintered, tubular solid electrolyte.

2. An element with a supporting thin-layer solid electrolyte, for example, YSZ, with a thickness providing sufficient strength, for example 100-150 microns, having spherical, pyramidal bulges located along the generatrix tube or with a shift of each row relative to the adjacent ones in a “short-circuit order”. Thin electrodes, for example, 20-50 μm, are located on the external and internal surfaces and are applied in the usual way, for example, by burning electrode pastes, onto a previously sintered, tubular solid electrolyte.

3. An element with a supporting internal electrode, for example, of strontium lanthanum manganite (LSM) or nickel cermet (Ni cermet) ("High-temperature electrolysis of gases" M..B. Perfiliev, AK Demin, BL Kuzin, AS Lipilin, ISBN 5-02-001399-4., M .: Nauka, 1988, 232c), the tubular structure has an internal, smooth cylindrical surface and an external "macro-shaped" surface in the form of corrugations along a generatrix in the form of a "wave", "trapezoid" , “Triangle” or spherical, pyramidal bulges located along the generatrix or with a shift of each row relative to the adjacent ones in the “shortest time” dke "(Figure 4 -. option waveform), on which a thin solid electrolyte, for example, with a thickness of 2-50 microns, and a thin external electrode, for example, with a thickness of 20-50 microns, are arranged and connected in series.

4. An element with a supporting external electrode, for example, of LSM or Ni cermet, of a tubular structure having an external, smooth cylindrical surface and an internal "macro-pleasing" surface in the form of corrugations along a generatrix in the form of a "wave", "trapezoid", "triangle" or spherical , pyramidal bulges located along the generatrix or with a shift of each row relative to the neighboring ones in a “latitudinal order” (Fig. 5 - a variant of a wave-like relief), on which a thin solid electrolyte, for example, YSZ with a thickness of 2-50 μm, and thin an external electrode, for example, of LSM or Ni cermet, with a thickness of 20-5 Ohm.

5. An element with supporting external and internal electrodes, for example, of LSM or Ni cermet, having respectively external and internal smooth cylindrical surfaces and located between them and connected with them a thin solid electrolyte, for example, YSZ with a thickness of 2-50 μm, made in the form corrugation along the generatrix in the form of a “wave”, “trapezoid”, “triangle” or spherical, pyramidal bulges located along the generatrix or with a shift of each row relative to the neighboring ones in a “latitudinal order” (Fig. 6 - variant of a wave-like relief).

The present application provides a method for manufacturing the above-mentioned tubular element design variants, which consists in the following operations:

• Formation of thin films of solid electrolyte, for example, YSZ, 5-30 microns thick, with a thermoplastic binder, for example, polyvinyl butyral, ^" according to technology, for example, film casting lavsan substrate or extrusion followed by kolondirovanie, using nano-sized and micro-sized powders for slip;

• Formation of thin films from electrode materials, for example, from LSM or Ni cermets, 5-100 microns thick, with a thermoplastic binder, such as polyvinyl butyral, using technology, for example, casting films on a lavsan substrate or extrusion followed by colondization, using nanoscale for slip and microsize powders;

• Formation of thin films of interface, transition layers, for example, of cerium doped with gadolinium (GDC), 5-10 microns thick, with a thermoplastic binder, for example, polyvinyl butyral, using technology, for example, casting films on an Ilsan substrate or extrusion, followed by extrusion, using for slurries, nanoscale and microsize powders;

• Cutting from films the required compositions and sizes of patterns of all components of the tubular element for electrochemical devices: solid electrolyte, electrodes (anode and cathode), interface layers;

• Winding on the steel rod the required number of film layers from materials of the necessary components of the tubular element for electrochemical devices: anode, interface layer, solid electrolyte, interface layer and cathode.

• Forming of all wound layers of tubular component components that provide the required tubular structure with a supporting electrolyte, with a supporting anode, a supporting cathode, supporting both electrodes under conditions of monolithic thermoplastic layers: at a temperature, for example, for PVB - 90-125 ⁰ C and a comprehensive pressure pressing, for example, magnetic pulse pressing (MIL) of 0.1-1.8 GPa; • Joint sintering of the multilayer structure of the tubular element is carried out under conditions providing a gas-tight, thin, layer of solid electrolyte and porous gas diffusion electrodes, for example, for YSZ layers of solid electrolyte from nanopowder with specific surface area S = 62 ± 4 m ² / g, apparent density 97 -98% of the theoretical value is achieved in the temperature range 950-1300 ⁰ C with a shutter speed of 100 - 0.33 hours, respectively.

Execution Example:

1. Polyvinyl butyral based slurries (10-14 wt%) were molded onto a lavsan substrate (film) by films from weakly agglomerated nanopowders (S = 60-65 m ² / g) of solid electrolytes based on zirconium dioxide and cerium with a thickness of 10-20 μm . From agglomerated micropowders (S = I 2-14 m ² / g) of the same materials, films about 5-10 microns thick were cast. A film 20–30 μm thick was cast from micropowder of the electrode material of strontium lanthanum manganite. From nanopowder films, separated from the mylar ribbon, patterns were cut that were wound in 6, 12 and 18 layers on a steel core of the mold. Then, after evacuation and heating to 125 ^° C, magnetic pulse pressing was performed (monolithic of thermoplastic layers) at a pressure of about 0.3 GPa and sintering in an atmosphere of air at a temperature of 115 ^° C for one hour. As a result, gas-tight tubes of solid electrolyte with a diameter of about 10 mm and a wall thickness of about 60, 120, and 180 μm with a grain size of ceramic of a submicron solid electrolyte of about 100 nm were obtained;

Claims

Claim

1. A tubular element for batteries of electrochemical devices with a supporting solid submicron electrolyte, gas diffusion electrodes and interface layers, characterized in that the supporting solid submicron electrolyte is made of nanopowder, for example, based on yttrium stabilized zirconium (YSZ), with a thickness providing sufficient strength, for example, 100-150 microns, with corrugations along the generatrix tube in the form of a wave, or trapezoid, or triangle, with thin interface layers of micropowder deposited on a corrugated surface t electrolyte, for example, cerium doped with gadolinium (GDC), or (YSZ), and thin, for example, 20-50 microns, gas diffusion electrodes, for example, of LSM or Ni cermets, deposited on the corrugated outer and inner surfaces of the electrolyte with interface layers .

2. A tubular element for batteries of electrochemical devices with a supporting thin-layer solid electrolyte, gas diffusion electrodes and interface layers, characterized in that the element is made with spherical, pyramidal bulges located along the generatrix tube or with a shift of each row relative to adjacent staggered, with thin interface layers deposited on a corrugated surface of a supporting solid electrolyte made of micropowder, for example, cerium doped with gadolinium (GDC) or (YSZ), and t thin, for example, 20-50 microns, gas diffusion electrodes, for example, from LSM or Ni cermet, deposited on the corrugated outer and inner surfaces of the electrolyte with interface layers.

3. A tubular element for batteries of electrochemical devices with a supporting internal electrode, a thin layer solid electrolyte, gas diffusion electrodes, interface layers and an external thin electrode, characterized in that with a supporting internal electrode, for example, of LSM or Ni cermet, with an inner smooth 'cylindrical surface and macro-outer surface in the form of corrugations along the generatrix in the form of "volny", "tpaiietsyi" ₅ "tpeygolnika" or spherical, pyramidal protuberances disposed along a generatrix or by shifting each th row in relation to the adjacent "shaxmatnom popyadke 'connected in series via an interface layer with a thin solid electrolyte, e.g., 2-50 microns in thickness, an interface layer and a thin outer electrode, for example, 20-50 microns thick.

4. A tubular element for batteries of electrochemical devices with a supporting external electrode, a thin layer solid electrolyte, gas diffusion electrodes, interface layers and a thin internal electrode, characterized in that the supporting external electrode, for example, from LSM or Ni cermet, with an external, smooth cylindrical surface and internal macrorelief surface in the form of corrugations along the generatrix in the form of a “wave”, “trapezium”, “triangle” or spherical, pyramidal bulges located along the generatrix or with a shift of each row and in relation to the adjacent "shaxmatnom popyadke 'connected in series via an interface layer with a thin solid an electrolyte, for example, 2-50 microns thick, an interface layer and a thin inner electrode, for example, 20-50 microns thick.

5. A tubular element for batteries of electrochemical devices with supporting external and internal electrodes, with a thin layer solid electrolyte, gas diffusion electrodes and interface layers, characterized in that the supporting external and internal electrodes, for example, of LSM or Ni cermet, have respectively external and internal smooth cylindrical surfaces between which a thin solid electrolyte, for example, YSZ 2–50 μm thick, made in the form of corrugations along a generatrix in the form of “wave”, is located and connected to them through interface layers ni ”,“ trapezium ”,“ triangle ”or spherical, pyramidal bulges located along a generatrix or with a shift of each row relative to the neighboring ones in a“ short order ”. b. A method of manufacturing a tubular element for batteries of electrochemical devices with a supporting thin layer solid electrolyte, gas diffusion electrodes and interface layers comprising pre-forming thin films from a suspension for the manufacture of components of a tubular element: electrolyte, interface layers and electrodes, while for the manufacture of a carrying thin-walled solid electrolyte suspension contains nanopowder, and for the manufacture of interface layers and electrodes, micropowder; winding thin films into a roll in the number of layers necessary to obtain the required thickness: thin films of the inner electrode, the interface layer, solid electrolyte, the interface layer and the outer electrode; molding the components of the tubular element, providing the desired design under conditions that provide monolithic layers, made on the basis of a thermoplastic binder: at a temperature of, for example, 90-125 ⁰ C for a polyvinyl butyral (PVB) binder and an all-round pressure of 0.1-1.8 GPa, for example, for magnetic pulse pressing; sintering of the components of the tubular element under conditions providing a gas-tight, thin layer of solid electrolyte and porous gas diffusion electrodes, for example, for YSZ layers of solid electrolyte from weakly agglomerated nanopowder with specific surface area S = 62 ± 4 m ² / g, in the temperature range 950-1300 With a shutter speed of 100 - 0.33 hours, respectively.

7. A method of manufacturing a tubular element for batteries of electrochemical devices with a supporting internal and / or external electrode, a thin layer solid electrolyte, gas diffusion electrodes and interface layers, comprising the preliminary formation of thin films, for example, by casting from a suspension containing a powder of the required composition, with a binder, the films of electrodes and interface layers are cast from micropowder, and solid electrolyte from nanopowder; winding thin films into a roll in the required sequence: a supporting internal electrode, for example, an anode or cathode, an interface layer, a solid electrolyte, an interface layer, an external electrode, for example, a cathode or anode, with the number of layers required to obtain the required thickness; forming the layers of the components of the tubular element necessary to obtain the desired design under conditions that ensure the monolithic layers due to the thermoplasticity of the binder: at a temperature of 90-125 ⁰ C, for example, for polyvinyl butyral (PVB) as a binder and a pressure of comprehensive pressing of 0.1-1.8 GPA, for example, for magnetic pulse pressing; sintering under conditions providing a gas-tight, thin layer of solid electrolyte and porous gas diffusion electrodes, for example, for YSZ layers of solid electrolyte from weakly agglomerated nanopowder with specific surface area S = 62 ± 4 m ² / g, in the temperature range 950-1300 ⁰ C with exposure 100 hours - 20 minutes respectively.