RU152522U1 - LITHIUM BATTERY - Google Patents

Abstract

Lb with pcm olkhit (And spiot d ppi pt pkkspsi rit pppmsptriotsp kpppppt atmptidt

Description

The utility model relates to the field of electrical engineering, in particular, electrical equipment, namely, a lithium battery for direct conversion of chemical energy into electrical energy, and can be used in the manufacture of batteries from lithium chemical current sources (IT), intended for primary and backup power supply systems telemechanics and signaling, autonomous diagnostic equipment for in-line inspection devices for oil and gas pipelines, as well as for use as ie autonomous power sources, various other electronic devices.

Known primary lithium battery containing at least two parallel circuits, each of which consists of series-connected primary lithium IT, combined in a single housing equipped with contact leads, while the battery is additionally equipped with an electronic controller that contains diodes, each of which connected in parallel with one IT, and at least two diodes connected in series after each IT, which is the last in each chain of IT connected in series, with each circuit serially connected primary lithium IT is further provided with a fuse connected between a common wire of parallel chains and the first IT chain. At least one circuit of series-connected primary lithium ITs can be additionally equipped with fuses connected between each IT circuit and its connection with a diode connected in parallel with IT (see RF patent for utility model No. 46388, IPC H01M 10/48, publ. June 27, 2005).

In a known design, diode protection of primary lithium IT from their polarity reversal of more than 0.5-1.0 V is used, in which a diode is connected in parallel with IT. However, such protection limits the IT polarity reversal voltage during its overdischarge, but does not protect IT from excessive deep discharge, which can lead to IT depressurization (explosion) and battery failure.

In addition, when the battery is discharged at an ambient temperature close to the maximum operating temperature due to the additional heat generation on the internal resistance of the current sources that make up the battery, they may overheat, that is, heat above the maximum allowable temperatures. Protection against overheating of current sources in this battery design is not provided. This can lead to a violation of the tightness of current sources and leakage of a chemically hazardous and aggressive electrolyte, which is unacceptable during operation.

Known primary lithium battery containing at least one circuit of successively connected positive and negative currents of primary lithium chemical current sources (IT), diodes, each of which is connected in parallel with one IT, field-effect transistors, a conducting channel of each of which is connected in series with appropriate IT, safety elements, each of which is connected between IT and its connection to the diode from the side of the positive IT current output, and is placed in the zone of heat energy flow about field effect transistor of the same IT FETs formed with a conductive P-channel, wherein the conductive channel of each of the transistors included between IT and its connection to the diode from the positive cold end IT, and the gate is connected to the cold end of the same negative IT. Safety elements can be made in the form of a thermal fuse or in the form of a self-healing fuse (see RF patent for utility model No. 106499, IPC H01M 10/48, published on March 21, 2011).

This battery design has protection against overdischarge of cells. But, since the protection elements (thermal fuses, resettable fuses) are installed in power current circuits (in series with IT), they are quite massive and inertial in response time. Due to the delay of the thermal fuse (or self-healing fuse) due to inertia, overheating of the field effect transistor and short circuit (thermal breakdown) of the conductive channel can occur. After a short circuit of the conductive channel, its electrical resistance will be sharply reduced, which will lead to cooling (lowering temperature) of the field-effect transistor housing. Under these conditions, a thermal fuse (or self-resetting fuse) will not be possible. Consequently, a deep discharge of elements is possible. As already noted, with a deep discharge, depressurization (explosion) of individual IT and the battery as a whole is possible, which is unacceptable in operation.

Protection against overheating of current sources in this battery design is also not provided. This can lead to a violation of the tightness of current sources and leakage of a chemically hazardous and aggressive electrolyte, which is unacceptable during operation.

Closest to the proposed technical solution is a well-known primary lithium battery containing at least one circuit of positive and negative current leads connected to primary lithium chemical current sources (IT), diodes, each of which is connected in parallel with one IT, field effect transistors, the conductive channel of each of which is connected in series with the corresponding IT, thermal fuses, each of which is located in the zone of the flow of thermal energy from the field effect transistor as IT. The battery is also equipped with resistors, each of which is connected to the gate of the field-effect transistor and the IT current output, to which the conductive channel of the same field-effect transistor is connected, and each thermal fuse is electrically connected between the gate of the corresponding field-effect transistor, in the zone of the flow of thermal energy of which it is located, and another current output the opposite polarity of the same IT (Application No. 2014128009/07 (045366) from 08/08/2014).

This battery has reliable protection against overdischarge of elements, but does not have protection against overheating, which is possible when the battery is discharged at an ambient temperature close to the maximum working temperature due to additional heat generation on the internal resistance of current sources. As noted above, this can lead to a violation of the tightness of current sources and leakage of a chemically hazardous and aggressive electrolyte, which is unacceptable during operation.

The objective of this utility model is to create a battery design with increased safety, due to the exclusion of overheating of the IT battery at high discharge currents and at an ambient temperature close to the maximum allowable working temperature.

The technical result achieved in solving the problem is to disconnect the load from the IT battery when they overheat due to the operation of a thermal fuse located simultaneously in the heat flow from the IT and in the heat flow from the field effect transistor.

The specified technical result is achieved in that a lithium battery containing at least one lithium chemical current source (IT) with positive and negative current leads, a diode connected in parallel to IT, a field effect transistor whose conductive channel is connected in series with IT, a resistor and a thermal fuse moreover, the resistor is electrically connected between the gate of the field effect transistor and one IT current output with polarity, to which the conductive channel of the field effect transistor is connected, and the thermal fuse is connected is between the gate of the transistor and another IT current output of opposite polarity and is located in the heat energy flow zone from the field effect transistor, according to a utility model, the thermal fuse is located simultaneously in the heat energy flow zone from the field effect transistor and in the heat energy flow zone from IT, while the thermal fuse operating temperature is in the range from the maximum permissible operating temperature for IT to the maximum permissible operating temperature for the field effect transistor.

The specified technical result is achieved due to the following.

The proposed utility model uses the technical solution of protection against overdischarge of IT, borrowed from the prototype. But, unlike the prototype, the thermal fuse is located simultaneously in the zone of thermal energy flow from the field effect transistor and in the zone of thermal energy flow from IT, and the temperature of the thermal fuse is in the range from the maximum permissible operating temperature for IT to the maximum permissible operating temperature for the field effect transistor.

This is due to the following.

The thermal fuse used in the prototype when it is heated from the field effect transistor during the closure of the conductive channel (with a deep discharge) is triggered and, thereby, disconnects the IT from the further discharge. The same function of disconnecting from the IT discharge in the proposed utility model is also carried out by the thermal fuse when it is heated from IT. Since the tripping temperature of the thermal fuse is in the range from the maximum permissible operating temperature for IT to the maximum permissible operating temperature for the field effect transistor, disconnection from the discharge occurs only in cases of overdischarge or overheating of the IT, but in the operating temperature range for the field effect transistor. This eliminates the overheating of the field-effect transistor (thermal breakdown) during operation of the protection device as a whole, which is especially important at high current loads and an ambient temperature close to the maximum allowable for IT. This ultimately increases the safety in operation of the proposed battery design in comparison with the prototype.

The utility model is illustrated by drawings. FIG. 1, FIG. 2, FIG. 3. In FIG. 1 shows an example of a circuit diagram using field-effect transistors with a conductive P-channel, and in FIG. 2nd conductive N-channel. In FIG. 3 shows the placement of the thermal fuse.

The numbers in the drawings indicate: 1 - lithium IT; 2 - diodes; 3 - field effect transistors; 4 - thermal fuses located simultaneously in the heat flow zone from the field effect transistor 3 and IT 1; 5 - resistors.

A lithium battery contains one lithium chemical current source (IT) with positive and negative current leads, made in the form of a unit, equipped with contact terminals for connecting an external load, for example, an electrical connector or terminals.

In parallel, IT 1 is connected to a diode 2, which provides shunting of IT 1 when it is fully discharged.

The battery is equipped with a field effect transistor 3, the conductive channel of which is connected in series with IT 1. Moreover, the conductive channel of the transistor 3 is connected between the corresponding current output of IT 1 and its connection to the diode 2, and the gate is connected to the current output of opposite polarity IT 1 through a thermal fuse 4. The gate is also connected through resistor 5 with a conductive channel on the side of its connection with current output IT 1. As shown in FIG. 3, the thermal fuse is structurally placed simultaneously in the zone of heat energy flow from the field effect transistor 3 and in the zone of heat energy flow from IT1, since all elements of the electrical circuit, including the thermal fuse, are located directly on the end cap IT1 (in the zone of heat energy flow from IT), and the thermal fuse, in turn, is placed in direct contact with the body of the field effect transistor (in the area of the flow of thermal energy from the field effect transistor). In this case, the temperature of the thermal fuse is in the range from the maximum permissible operating temperature for the current source to the maximum permissible operating temperature for the field effect transistor. All elements of the electrical circuit to prevent the ingress of any conductive contamination are protected (flooded) with an electrical insulating compound.

As the field effect transistor 3 (see the drawing - Fig. 1), for example, field effect transistors with a conductive P-channel - IRF7210, IRF7220, IRF7225, IRF7240 manufactured by InternationalRectifier (IR) can be used.

In the drawing - figure 2 presents a similar circuit of a battery with field effect transistors with a conductive N-channel, for example, IRLR2905, IRL 2505, IRL 2705, IRF7401 manufactured by InternationalRectifier (IR).

As a thermal fuse 4, for example, small-sized thermal fuses of the TZK-10, TZK-11, TZK-12, TZK-13, TZK-14 series manufactured by Bourns, Inc (USA) with a response temperature in the range of 100 ÷ 150 ° C can be used.

As the resistor 5 can be used, for example, surface mount resistors of 0.1-10.0 MΩ type SMD from various manufacturers.

As a current source IT1, for example, a current source SPL-16S manufactured by Sehoon (South Korea) can be used.

The lithium battery operates as follows.

During battery discharge, the operating voltage of IT 1 decreases. In the initial stage of a deep discharge of IT 1, the field effect transistor 3 disconnects it from the discharge, thereby eliminating the overdischarge of IT 1 and the polarity reversal. This is as follows. When the discharge voltage IT 1 decreases below the final voltage (the final voltage, as a rule, is 2.0 V), the conducting channel of the field-effect transistor 3 closes. The resistance of the conductive channel of the field-effect transistor 3 increases sharply (in millions of times) and, for example, reaches 1.5–5.0 MΩ even at 1.5 V. Thus, when the conductive channel is closed, IT 1 is disconnected from the discharge circuit. If a discharge uses several batteries of the same type connected in series, the discharge of the remaining batteries continues, and the current flows through a shunt diode 2, which is connected in parallel with IT 1.

In the process of closing the field effect transistor, due to an increase in the resistance of the conductive channel, it heats up. In the zone of thermal energy flow from the field effect transistor 3, to prevent its thermal breakdown, a thermal fuse 4 is placed, which is heated by the field effect transistor 3, and when a certain temperature is reached (within the permissible operating temperature of the field effect transistor 3), it trips and breaks the control circuit. Moreover, given that the gate of the field-effect transistor 3 is connected through a resistor 5 to the conductive channel, when the thermal fuse 4 is activated, the gate potential becomes equal to the potential of the conductive channel. Under these conditions, the transistor 3 instantly closes and the flow of electric current through IT 1 stops. In order to turn off and keep the field effect transistor in good condition, it is necessary that the temperature of the thermal fuse does not exceed the maximum allowable operating temperature of the field effect transistor.

If the battery discharges at an ambient temperature close to the maximum permissible, then due to the additional release of thermal energy on the internal resistance of IT1, it can be heated above the permissible temperature. In the proposed utility model, a thermal fuse is located on the cover of IT1. When IT1 is heated to the thermal fuse tripping temperature, IT1 is disconnected from the discharge by the same mechanism as during overdischarge, and IT1 is further heated up, which increases the safety in operation of the proposed battery design in comparison with the prototype.

Thus, the proposed utility model excludes not only potentially dangerous deep discharge and IT polarity reversal, but also IT overheating, which can lead to IT explosion, which significantly increases the fire and explosion safety of the battery in operation and the reliability of the battery as a whole.

Claims (1)

Lb with pcm olkhit (And spiot d ppi pt pkkspsi rit pppmsptriotsp kpppppt atmptidt

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