RU196615U1 - Autonomous battery module based on lithium polymer batteries - Google Patents

Abstract

The utility model relates to the field of energy supply, namely to stand-alone battery modules based on prismatic lithium-polymer batteries. A stand-alone battery module based on prismatic lithium-polymer batteries contains the front and rear support walls, the same type of battery cells, horizontal spacers, electronic unit, terminals, side walls, front and rear outer walls, cover, base. The battery cells are connected in series in an electric circuit and are arranged at a constant interval, providing a through section of the air cooling channels. The electronic unit provides control of parameters and leveling the unbalance of voltage of the battery cells. Horizontal spacers are located between the battery cells, between the cells and the supporting walls. Spacers provide air cooling of the battery cells. The base, the top cover with perforation, the side, front and rear outer walls, as well as the cover are connected to each other and the base using fasteners, forming a collapsible housing-protection for terminals, battery cells and the electronic unit from mechanical damage. The technical result consists in increasing the reliability of operation of an autonomous battery module with air cooling, increasing the life of the battery module and expanding the range of operating currents due to more intensive air cooling of the battery module, while maintaining the level of protection against mechanical damage and the simple design of the battery module. 5 cp f-ly, 4 ill.

Description

The utility model relates to the field of energy supply, more specifically to means of energy storage, and is intended primarily for use in transport engineering as a part of energy-supplying complexes of vehicles equipped with a traction electric drive.

The prior art lithium-ion secondary battery (RU 103675 U1, 04/20/2011), which consists of prismatic lithium-ion secondary cells connected in series into an electric circuit and separated from each other and from the walls of the battery case by dielectric spacers. Battery cells are placed in recesses of complex shape, made in spacers that are mounted on a cooled base of the battery. All components of the battery are pulled together with power pins. The method of cooling the battery cells does not provide a uniform temperature field on their entire surface, because heat transfer is carried out from a small area of the cell bottoms, and uneven heating of the batteries can lead to a decrease in electric capacity during cycling (charge / discharge).

A high-power battery is known from the prior art (RU 155156 U1, 09/20/2015), containing a block of flat lithium-polymer batteries connected in series and installed in polyamide frames equipped with holes for couplers to secure the batteries in the block and blocks in the battery. Between the batteries in the unit, metal heat sinks are installed with an increased heat transfer surface at the ends, which transfer heat to the casing walls through heat-conducting electrical insulating gaskets, and a power switch board based on an aluminum base of an electronic battery monitoring and control system is installed on the battery base through a heat-conducting electrical insulating gasket. On the inner surface of the casing, a coating of heat-insulating fine-meshed foamed polyurethane is coated, which makes it possible to maintain heat inside the battery at low temperatures at low discharge currents and ensure its discharge capacity up to 75% of the nominal. On the other hand, this technical solution significantly reduces the permissible discharge current of the battery and, accordingly, its capacity, at a positive ambient temperature. It should also be noted that the battery has three electronic boards: two control boards, a power switch board and a temperature sensor board, which greatly complicates the design and reduces its reliability and fault tolerance.

The prior art battery module based on lithium-polymer batteries with improved conditions for heat transfer between cells (US 2007/0037051 A1, 02/15/2007), containing the front and rear end plates and located between them in series connected in the electric circuit of the same type of battery cells of a prismatic shape , each of which is placed in the spacer with the provision of air cooling channels, as well as tightening studs that close the compressive force on the end plates. Spacers in it are installed between the battery cells in such a way that one spacer is placed between two adjacent cells, covering the cell with its three sides: the front and two side or two sides: the front and side, and these sides of the spacers contain several grooves made through The assembled battery module is formed by horizontally arranged channels for the passage of the cooling fluid.

However, in the assembled battery module, such a constructive construction of spacers, if necessary, to provide the required strength parameters, can lead to a rather significant overlap of the front surfaces of the battery cells with jumpers between the grooves, while the air cooling channels will have a relatively small total flow area - this will complicate air circulation and heat dissipation . Therefore, despite the presence of air cooling channels, the heat sink system is not able to provide uniform and sufficient heat removal at maximum electric loads on the battery module, which should be attributed to its main drawback, which leads to a decrease in the resource and reliability of the module.

The prior art electric battery (US 2009/0253026 A1, 10/08/2009), containing many energy-generating elements (electrochemical cell of a lithium-ion or lithium-polymer type) packed in a flexible sealed enclosure that protects the housing from mechanical and thermal damage, made of heat-conducting material. This housing has two longitudinal elements and many transverse elements connecting these longitudinal elements, forming compartments for electrochemical cells. The specified housing includes circulation channels for the liquid coolant.

A serious drawback of this design is the impossibility of ensuring a tight fit of the electrochemical cells to the transverse elements along which the liquid coolant passes. This is due to the presence of a tolerance on the thickness of the cells and the dimensions of the case, therefore, it is equally likely that there is an air gap that reduces the heat transfer rate and causes excessive heating of the cells, and that the permissible compression loads of the cells are exceeded, which can lead to mechanical damage.

In addition, the known battery modules based on lithium-polymer batteries, the production of which is engaged in the South Korean company KOKAM CO LTD, which owns the following patent documents.

KR 101853907 B1, 05/02/2018, in which water cooling of battery cells is disclosed, located in the cartridges between each cells in such a way that the cells contact the liquid coolant directly. A design with such cooling increases the weight of the battery module and reduces the term of its safe operation. The tightness of the connection of the cooling cartridges and battery cells is ensured by rubber gaskets. Over time, during operation or storage, the sealing properties of the gaskets will inevitably deteriorate, and the failure of one of the seals will lead to the penetration of the liquid coolant into the zone of electrical contacts and short circuit.

KR 20140042059 A, 04/07/2014, in which a battery module with a plurality of battery cells, a plurality of cartridges for these cells is disclosed, and a heat sink may be located between adjacent cartridges in one embodiment. This design also increases the weight of the battery module. In addition, when using the option with heat sinks, when the cells are heated and expand, their excessive compression can occur. In the design variant without heat sinks, this drawback is eliminated, but the heat transfer efficiency between the battery cells and the frames is significantly reduced, because the main part of the thermal energy is released on the vertical planes of the cells, which are in contact with a closed air gap.

KR 20180012984 A, 02/07/2018, in which a battery module with battery cells stacked on top of one another, an air purge unit, a suction unit connected to a plurality of battery cells and located opposite to the purge unit (air-emitting device), and flow separation and distribution elements are disclosed air. A design with such cooling also increases the weight of the battery module, and also complicates the design and reduces energy efficiency in general, as additional energy is used to drive the discharge and suction fans.

The closest analogue (prototype) of the proposed utility model is a battery module based on lithium-polymer batteries (RU 142206 U1, 06/20/2014) containing the front and rear end plates and the same type of battery cells located in series between them, connected in an electric circuit, each of which placed in a spacer with air cooling channels. Spacers are made in the form of a detachable housing element composed of two pairs of opposite side racks. The front and rear covers of the module, together with the spacers, form the module housing, which protects the battery cells from possible mechanical damage during operation.

Such a design of the battery module increases the weight of the battery module, and also complicates the design with relatively non-intensive air cooling of the battery cells, which reduces the reliability of the autonomous battery module with air cooling, reduces its service life and limits the range of possible operating discharge currents.

The problem solved by the utility model is aimed at developing an effective stand-alone battery module based on lithium-polymer batteries, which has an increased resource and reliability.

The technical result consists in increasing the reliability of operation of an autonomous battery module with air cooling, increasing the life of the battery module and expanding the range of operating currents due to more intensive air cooling of the battery module, while maintaining the level of protection against mechanical damage and the simple design of the battery module.

The technical result is achieved by the fact that an autonomous battery module based on lithium-polymer batteries of a prismatic shape, containing front and rear support walls and located between them with a constant interval, providing a through section of air cooling channels, series cells of the same type, connected to the electric circuit, mounted on the front wall of the electronic unit for monitoring parameters and leveling the unbalance in the voltage of the battery cells, to which connected to the terminals of the cells, characterized in that it is provided located between the battery cells, as well as between the first extreme battery cell and the front support wall, between the second extreme battery cell and the rear support wall, horizontal spacers that prevent the cells from touching each other and the cells touching with front and rear support walls, and the thickness of the fixed spacer determines the size of the air channels, front and rear outer walls, side walls with perforation, providing air cooling, the base and the top cover with perforation, while the intermediate plate, the side, front and rear outer walls, as well as the cover are connected to each other and to the base by means of fasteners, forming a collapsible housing-protection for terminals, battery cells and the electronic unit from mechanical damage.

The design of the stand-alone battery module also has the following additional differences.

The spacers are equidistant from the edges of the electrolyte-filled part of the battery cell with which they are fixed, one spacer is located at the bottom, one is located at the top, the indicated arrangement of the spacers prevents the cells from touching each other and the cells touching the housing covers. This arrangement of the spacers provides a constant height clearance of the air gap, while at the same time not significantly reducing its cross-sectional area. A smaller number of spacers (one) will lead to uneven width (on the side where there is a spacer, the gap width is maximum, but tends to zero on the opposite side).

Spacers are made in the form of elongated flat rectangular plates, with the wide side adjacent to the battery cells, which simplifies the manufacturing process and the assembly of the battery module due to their simple shape.

Spacers are connected to the battery cells by an adhesive connection, which simplifies the assembly of the battery module, disassembly in the event of a battery cell malfunction, and also reduces the weight of the stand-alone battery module by eliminating other common types of fasteners with a higher mass.

A removable handle fixed to the mounting plate with fasteners, which simplifies the transfer of the battery module, its installation in a vehicle and removal for inspection or repair.

The case is made of composite material, which is based on plastics, which ensures a reduction in the mass of an autonomous battery module while maintaining the reliability of the structure, and also eliminates the possibility of shorting any electrical contact to the case.

In the drawings:

in FIG. 1 shows a general view of an autonomous battery module (isometric view);

in FIG. 2 is a view of an autonomous battery module illustrating its internal structure (isometric view);

in FIG. 3 is a view of an autonomous battery module illustrating an internal structure (side view);

in FIG. 4 shows a three-dimensional view of the battery cells assembly with spacers (isometric view).

1 - Base

2 - Side wall

3 - Mounting plate

4 - Battery cell

5 - Horizontal spacer

6 - The filled part of the cell

7 - Cell protrusion

8 - Rear back wall

9 - Front support wall

10 - Front outer wall

11 - Rear outer wall

12 - Cover

13 - Tire

14 - Pressure bar

15 - Management Board

16 - wiring harness

17 - Cell contacts

18 - Handle

19 - Fasteners.

The proposed stand-alone battery module contains series-installed battery cells 4 of a prismatic shape with a lithium-ion polymer electrolyte.

The battery cells 4 are arranged vertically parallel to each other so that the negative and positive contacts of adjacent cells are located opposite each other. Cell 4 comprises a protrusion 7 and a portion filled with electrolyte 6. The protrusion of the cell at the top contains the anode and cathode, which make the contacts 17. The contacts 17 of the battery cells 4 pass through the slots in the mounting plate 3 and are pressed by the straps 14. The straps are attached to the mounting plate by screws, which ensures that the contacts are clamped to each other and a reliable electrical connection.

Between all cells there are horizontal spacers 5, made in the form of rectangular plates, made of dielectric material, equipped with an adhesive layer on the surfaces in contact with the battery cells 4. Horizontal spacers ensure uniform distribution of cells in the module and guarantee the presence of air channels between the cells. The air passing through these channels cools the cells during their operation. Spacers 5 are equidistant from the edges of the portion of the battery cells 4 filled with electrolyte 6, one spacer is located below, one is located above, with a distance between two spacers greater than from the spacer to the cell edge. Adhesive bonding simplifies the process of assembling the battery module, disassembling in the event of a battery cell malfunction, as well as reducing the mass of the stand-alone battery module.

The battery cells 4 with their lower part rest on a vibration-proof material glued to the base 1. The side walls 2 with perforation are attached to the mounting plate 3 and the base 1 with fasteners 19.

The rear 8 and front 9 supporting walls are attached to the side walls 2 by fasteners 19 and prevent the displacement of the battery cells. A control board 15 is also installed on the front wall 9, which is designed to control the parameters of the battery and level the unbalance of the voltage of the battery cells 4.

The wiring harness 16 is used to connect the terminals of the battery cells 4 with the control board 15.

To the contacts of the first and last cells 4 with the help of clamping strips 14 are attached tires 13, intended for connection with a consumer or charger.

Outer walls - front 10 and rear 11 are connected by fasteners to the side walls 2. The main function of the front walls is protection against mechanical damage to the battery cells and control board.

The cover 12 is installed in the upper part of the module and is attached to the side walls 2 by fasteners, the perforation of the cover ensures the removal of heated air from the contacts of the battery cells.

The removable handle 18 is mounted on the mounting plate 3 with the help of fasteners 19, which pass through the walls with perforation while additionally holding the walls on the battery module. The presence of the handle 18 simplifies the transfer of the battery module, its installation in a vehicle and removal for inspection or repair. For reliability and durability, the handle 18 can be made of various metals and their alloys.

The elements of the collapsible housing are made of composite material, which is based on plastics, which ensures a reduction in the mass of the autonomous battery module while maintaining the reliability of the design, and also eliminates the possibility of shorting any electrical contact to the housing.

The work of the autonomous battery module is divided into two modes: the module charge and its discharge, carried out in normal mode.

The heat energy released during cycling of the battery cells 4 is transferred from the front surfaces of the cells to the air gap between the cells 4 provided in the module. The spacers 5 form horizontal air cooling channels of the cells 4, the air through which passes through the perforated side walls 2.

If necessary, when convective heat transfer is not enough to cool the battery cells 4, the module can be equipped with electric fans or other sources of air supply, providing forced circulation of cooling air. Since, as you know, the unbalance of individual battery cells 4 is a negative phenomenon in the operation of the module, leading to a decrease in the operating voltage and a decrease in the amount of stored energy, which reduces the electric capacity of the module and, accordingly, reduces the range of the electric vehicle, and the main reasons for the unbalance several, for example: non-identical characteristics of cells 4, determined by deviations during the manufacturing process, unequal initial state 4 cells before installing them in the module, as well as a different temperature state of cells 4, then during these modes it is very important to control the imbalance of the battery cells 4, which means the difference in the value of the remaining charge of the individual cells 4.

In the proposed module, when at least one battery cell 4 reaches the maximum / minimum value in terms of charge / discharge of the cell, the control board 15, receiving information about the state of the cells through the wiring harness 16, stops the charge / discharge process in accordance with the safety requirements for the operation of battery cells with lithium-ion polymer electrolyte, which can be a fire hazard when overcharging / overdischarging, characterized by the output voltage of the battery cell 4 beyond the permissible limits.

In addition, due to the functionality of the board 15, the competitive advantage of the proposed stand-alone battery module is the possibility of its self-diagnosis, dynamic assessment of the degree of charge, the correction of output characteristics depending on both the current state and the forecast.

In addition, due to its design, namely by reducing the number and mass of body parts, the manufacturing and assembly process of the battery module is simplified and an increase in the specific capacity of the module is achieved.

Claims (6)

1. An autonomous battery module based on lithium-polymer batteries of a prismatic shape, containing front and rear support walls and located between them with a constant interval, providing a passage section of air cooling channels, the same type of battery cells connected in series to an electric circuit, an electronic unit mounted on the front wall for monitoring parameters and leveling the unbalance of the voltage of the battery cells, to which the terminals of the cells are connected, characterized in that it is provided located between the battery cells, and also between the first extreme battery cell and the front support wall, between the second extreme battery cell and the rear support wall, horizontal spacers that prevent the cells from touching each other and the cells contacting the front and rear supporting walls, the thickness of the fixed spacer determines the size of the air channels, the front and rear outer walls, side walls with perforation, providing air oh the base, and the top cover with perforation, while the intermediate plate, the side, front and rear outer walls, as well as the cover are connected to each other and to the base using fasteners, forming a collapsible housing-protection for terminals, battery cells and electronic unit from mechanical damage. 2. The stand-alone battery module according to claim 1, characterized in that the spacers are equidistant from the lower and upper edges of the electrolyte-filled part of the battery cell with which they are fixed, one horizontal spacer on the edge. 3. The stand-alone battery module according to claim 1, characterized in that the spacers are made in the form of elongated flat rectangular plates of dielectric material. 4. The stand-alone battery module according to claim 1, characterized in that the spacers are connected to the battery cells by an adhesive connection. 5. The stand-alone battery module according to claim 1, characterized in that it comprises a removable handle fixed with a mounting plate by fasteners through the side walls. 6. The stand-alone battery module according to claim 1, characterized in that said housing elements are made of a composite material based on plastics.

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