RU2746268C1 - Battery of thermoactivated chemical current sources - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering, in particular to thermal chemical current sources (TCCS), which can be used as stand-alone backup power supplies with an increased service life, activated from an external heat source. The battery contains a sealed metal case, inside of which, on a central insulated tightening rod, primary electrochemical cells are assembled in series and installed vertically in a block, each of which contains an anode and cathode half-cells, consisting of an active mass of the corresponding electrode material pressed into a bowl-shaped metal case. The half-cells are separated by a layer of electrolyte mixture pressed between their bodies, while the primary electrochemical cells are assembled with each other in such a way that the metal body of the anode half-cell has electronic contact directly with the metal body of the cathode half-cell. The battery contains external electrically insulated current leads, and the battery case is provided with a layer of high-temperature composite electrical insulation from the inside.

EFFECT: increased specific energy intensity of TCCS with possibility of repeated activation.

1 cl, 5 dwg

Description

The invention relates to electrical engineering, in particular, to thermal chemical current sources (TChIT), which can be used as stand-alone backup power supplies with an increased service life, activated from an external heat source.

Thermal chemical current sources based on electrochemical cells are widely known. Their advantages include a long, up to 25 years storage period without loss of electrical capacity, lack of maintenance, the ability to obtain any power and energy characteristics. When developing the designs of TCIT batteries, as standby power sources, the tasks of mass-dimensional parameters, increasing the service life and shelf life, energy consumption, as well as improving the reliability of operation and simplifying the battery assembly technology are mainly solved.

The principle of modern thermal chemical current sources is based on the use of electrochemical cells (ECE), each of which contains a calculated number of layers of active masses of the cathode and anode half-cells minimized in thickness, separated from each other by a layer of electrolyte mixture [1-4]. Primary electrochemical cells are assembled in a block in series, vertically, in a so-called "pillar", on a central insulated tie rod. Between the half-cells, solid layers of pyrotechnic heating elements pressed into the metal shell are introduced, designed to heat the ECE to the operating temperature and to provide electronic contact between the cathode and anode half-cells. To activate the batteries, that is, to bring them into working condition, an electric igniter is used, which is an integral part of the structure.

Thus, from the prior art, the design of standby autonomous power supplies is known, the principle of operation of which is based on the fact that when the layers of active masses of the cathode and anode half-cells are heated to the operating temperature, carried out by pyroheaters, the ion-conducting medium acquires purely ionic conductivity of electric current on the block of electrochemical cells there is a potential difference. However, heat batteries, in which the layers of active masses of the cathode and anode half-cells are heated by pyro-heaters, firstly, can be used once, and secondly, in such a battery it is difficult to provide the required temperature regime for the functioning of electrochemical cells for a long time. Thirdly, in order to use such a battery, it is difficult to correctly calculate the amount of pyrotechnic mixture at a sufficiently wide range of ambient temperatures (from -50 to + 50 ° C). Moreover, the need to use the calculated number of layers of active masses of the cathode and anode half-cells minimized in thickness is a limitation, which entails a decrease in the battery capacity.

In addition, to preserve internal heat, such batteries are made single-case with an inner layer of heat-insulating material or, according to the "thermos" principle, double-case, with appropriate thermal insulation, which provides a temperature regime inside the battery case, in which the electrochemical cells are operable. This complicates the battery assembly process, as they all contain heating elements that require activation devices. However, with all possible options for using thermal insulation and structural elements aimed at maintaining high temperatures in a small battery volume, the maximum operating time of known batteries does not exceed 1 hour, which is due to the intense heat sink into the surrounding space and the absence of a heat source inside the battery, which could provide compensation for heat loss. It should also be noted that due to the requirements of autonomous activation, replacement of heating elements in known batteries is not provided, therefore, power supplies of this type are disposable products.

As a prototype of the claimed invention adopted the simplest design single-case thermal battery according to RU50718 [1]. This battery contains a housing, the inner surface of which is covered with a layer of thermal insulation. Inside the housing, on a central insulated tightening rod, primary electrochemical cells are assembled in series, vertically into a block, each of which contains an anode and cathode half-cells, consisting of an active mass of the corresponding electrode material, pressed into a bowl-shaped metal body. A layer of electrolyte mixture is pressed between the half-cells, separating the half-cells from the electronic contact. The primary electrochemical cells are assembled with each other in a block in such a way that the metal body of the anode half-cell has electronic contact with the heating element, which is a layer of pyrotechnic composition pressed into the metal shell, and through this heating element - with the metal body of the cathode half-cell. The battery has external electrically insulated current taps.

The battery contains a system of electric ignitors to bring it into operation. This battery has all the disadvantages of the above known batteries, including one-time activation and a relatively short operating time, which for this battery is no more than 20 minutes.

The objective of the present invention is to create a battery design for thermoactivated chemical current sources with a service life of at least 5 to 8 hours and the possibility of repeated activation until the full depletion of the electrical capacity embedded in them.

For this, a battery of thermoactivated chemical current sources is proposed, which, like the prototype, contains a sealed metal case, inside the case on a central insulated tightening rod, primary electrochemical cells are assembled in series, vertically into a block, each of which contains an anode and cathodic half-cells, consisting of an active mass the corresponding electrode material pressed into a bowl-shaped metal body, the half-cells are separated by a layer of electrolyte mixture pressed between their bodies, while the primary electrochemical cells are assembled with each other with the possibility of electronic contact, and the battery has external electrically insulated current leads,

The new battery differs in that the primary electrochemical cells are assembled with each other in such a way that the metal case of the anode half-cell has electronic contact directly with the metal case of the cathode half-cell, while the battery case has a layer of high-temperature composite electrical insulation from the inside.

The essence of the claimed invention is as follows. The fact that, in the proposed battery design, the metal body of the anode half-cell has electronic contact directly with the metal body of the cathode half-cell makes it possible to exclude pyrotechnic heaters and their attendant activation components from the battery. The need for thermal insulation, which is replaced by a high-temperature composite electrical insulating layer that conducts heat well, does not lose its properties at high temperatures (above 500 ° C), and also prevents the possibility of a short circuit between the half-cells, is also eliminated.

Such a battery design can be activated from an external heat source, which can be a stove, fire, gas or gasoline burner or any other external heat source that can heat the battery up to an operating temperature of 500 ± 50 ° C. The single-case battery accelerates the heating of the TCIT cell block.

After partial use of the capacity of the battery cells, its heating stops. It cools down, while the self-discharge of its elements does not occur. Re-activation of the battery, as well as all subsequent operations, are carried out in the same way, while its electrical characteristics practically do not change until the final use of the electrical capacity inherent in its elements. The service life of such a battery depends on the number of active materials embedded in the TCIT elements and can be at least 5 - 8 hours.

The new technical result achieved by the claimed invention consists in a significant increase in the specific energy content of the heat battery and ensuring the repeated activation of the battery, which makes it possible to expand the field of application of the battery as a backup source of power supply.

The invention is illustrated in the drawings, where figure 1 shows a primary electrochemical cell; figure 2 is a sectional view of a primary electrochemical cell; figure 3 shows a General view of the thermal battery in section; Fig. 4 shows a diagram of the assembly of primary electrochemical cells in the prototype, where the surface of the electronic contact is between the metal body of the anode half-cell and the heating element, and also between the heating element and the metal body of the cathode half-cell: Fig. 5 is a diagram of the assembly of the primary electrochemical cells of the claimed battery where the surface of the electronic contact is directly between the metal case of the anode half-cell and the metal case of the cathode half-cell.

The battery of thermoactivated chemical current sources contains a housing 1, which has a layer of high-temperature composite electrical insulation 2 on the inside, capable of withstanding temperature changes without destroying the electrical properties of the battery. The layer of electrical insulation can be made of "Miniplen" material. In the center of the housing 1, a tightening rod 3 with an insulating coating is fixed. On the rod 3, primary electrochemical cells 4 are assembled sequentially, vertically in a block, in the so-called "pillar".

Each electrochemical cell 4 contains an anode half-cell 5, consisting of an active mass of a lithium-containing anode pressed into a bowl-shaped metal body 6, and a cathode half-cell 7, consisting of an active mass of halides or transition metal oxides or a mixture thereof pressed into a similar bowl-shaped metal body 8. The bowl-shaped metal cases of the half-cells have beads 9 and 10, which allow increasing the diameter of the layer of the low-melting salt mixture of lithium halides thickened with lithium aluminate 11, which is pressed between the half-cells 5 and 7 to reliably separate these half-cells from the electronic contact and prevent short circuits.

The battery of thermoactivated chemical current sources has external electrically insulated current leads 12, while the block of primary electrochemical cells is isolated from the central rod by a ceramic tube 13. To determine the readiness for use of the battery, an operating status indicator is built into it (not shown in the figure).

The use of a battery of thermoactivated chemical current sources is as follows. Depending on the design, the battery is placed in a heat source such as a fire, stove, etc., or exposed to a gas or gasoline burner. The battery is warmed up until the operating status indicator shows its readiness for operation. The operating time of the battery depends on its design, the electrical capacity embedded in the primary electrochemical cells, the method of putting it into working condition and can range from a few seconds to 10-15 minutes. After partial use of the battery capacity, its heating stops, the battery cools down and can be stored any time until the next activation. Self-discharge of the battery cells does not occur in the cold state. The battery allows repeated activation until the full depletion of the electrical capacity inherent in it.

Thus, the design of a battery of thermoactivated chemical current sources has been created with a service life of at least 5 - 8 hours and the possibility of repeated activation until the full depletion of the electrical capacity embedded in TCIT.

Information sources:

1. RU50718, publ. 02/20/2006;

2. RU No. 2369944, publ. 10.10.2009;

3. RU2508580, publ. 02/27/2014;

4. RU2573860, publ. 01/27/2016

Claims (1)

A battery of thermoactivated chemical current sources containing a sealed metal case, inside the case on a central insulated tightening rod, primary electrochemical cells are assembled vertically in series in a block, each of which contains an anode and cathode half-cells, consisting of an active mass of the corresponding electrode material pressed into a bowl-shaped metal case, half-cells are separated by a layer of electrolyte mixture pressed between their bodies, while the primary electrochemical cells are assembled with each other with the possibility of electronic contact, and the battery has external electrically insulated current leads, characterized in that the primary electrochemical cells are assembled with each other in such a way that the metal body of the anode the half-cell has electronic contact directly with the metal body of the cathode half-cell, while the battery body has a layer of high-temperature composite electrical insulation from the inside.

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