CN111653707A - Soft packet of lithium cell group prevents delaying burning structure - Google Patents

Abstract

The invention discloses a delay burning prevention structure of a soft-package lithium battery pack, and relates to the technical field of soft-package lithium battery packs, wherein the soft-package lithium battery pack comprises a plurality of battery cells, and the battery cells are arranged in a battery shell; heat insulation cotton is pasted and covered between the adjacent electric cores, and glass fiber cloth is pasted and covered on the surfaces of the two electric cores on the outermost layer and used for protecting the electric cores on the outermost layer; carrying out nickel conversion on the positive aluminum tab of the battery cell, and folding the positive aluminum tab after nickel conversion back to the groove of the battery cell and dispensing and fixing; EVA foam is pasted at the groove of the battery cell, and a positive electrode aluminum tab and a negative electrode tab of the battery cell are pasted on the EVA foam; a PCB wiring board is arranged above the battery cells, and positive aluminum tabs and negative aluminum tabs of the battery cells penetrate through the wiring board. The invention solves the safety problem of thermal runaway delay burning of the PACK module of the soft-package polymer lithium battery.

Description

Soft packet of lithium cell group prevents delaying burning structure

Technical Field

The invention relates to the technical field of soft-package lithium battery packs, in particular to a delay burning prevention structure of a soft-package lithium battery pack.

Background

Because soft packet of lithium cell is in electric power assisted bicycle, the application on the electric motor car, and battery module generally adopts between electric core and the electric core one adjacent one to pile up and constitute in the existing market, there is not thermal runaway to prevent to prolong the design of burning the structure between whole battery module electric core and the electric core, and the thermal runaway explosion of soft packet of lithium cell group the emergence of the safety problem of firing, the bulk application in electric motor car market of soft packet of lithium cell has been hindered, under this background, become the key problem of whole car factory and the urgent solution of battery enterprise.

Therefore, it is desirable to provide a new anti-ignition structure for soft-packed lithium battery pack to solve the above problems in the prior art.

Disclosure of Invention

The invention aims to provide a soft-package lithium battery PACK burn-delaying prevention structure, which is used for solving the safety problem of thermal runaway burn-delaying of a soft-package polymer lithium battery PACK module.

In order to achieve the purpose, the invention provides the following scheme: the invention provides a soft-package lithium battery pack anti-delay burning structure, wherein the soft-package lithium battery pack comprises a plurality of battery cells, and the battery cells are arranged in a battery shell; heat insulation cotton is pasted and covered between the adjacent electric cores, and glass fiber cloth is pasted and covered on the surfaces of the two electric cores on the outermost layer and used for protecting the electric cores on the outermost layer; carrying out nickel conversion on the positive aluminum tab of the battery cell, and folding the positive aluminum tab after nickel conversion back to the groove of the battery cell and dispensing and fixing; EVA foam is pasted at the groove of the battery cell, and a positive electrode aluminum tab and a negative electrode tab of the battery cell are pasted on the EVA foam; a PCB wiring board is arranged above the battery cells, and the positive aluminum lug and the negative lug of the battery cells penetrate through the PCB wiring board.

Preferably, the positive electrode aluminum tab and the negative electrode tab of the battery cell are integrally formed into an L shape and attached to the EVA foam.

Preferably, the wiring board is a PCB wiring board, and a nickel block is attached to the PCB wiring board.

Preferably, the positive electrode aluminum tab and the negative electrode tab of the battery cell are connected with the PCB wiring board in a spot welding manner.

Preferably, the PCB wiring board is provided with heat dissipation air holes, and the PCB wiring board is pasted with insulating sheets.

Preferably, positive and negative leads of a power supply of the soft package lithium battery pack are connected through terminals of a wiring board and are fixed in a wire groove of the battery plastic frame.

Preferably, the size of the heat insulation cotton is larger than that of the battery core, and fireproof double-sided adhesive tapes are pasted on the double sides of the heat insulation cotton.

Preferably, heat-conducting silica gel is filled in a groove between the battery core and the heat insulation cotton at the contact position between the head and the tail of the soft-package lithium battery pack and the battery shell, and is tightly bonded with the battery shell.

Preferably, the battery casing is the battery plastic frame of fretwork, battery plastic frame includes left battery plastic frame and right battery plastic frame, left side battery plastic frame with right side battery plastic frame connects through the buckle.

Preferably, the battery shell is a sealed plastic shell, the sealed plastic shell comprises a left sealed plastic shell and a right sealed plastic shell, the left sealed plastic shell and the right sealed plastic shell are connected through a buckle, and a sealing groove is formed in the joint; radiating ribs are uniformly distributed on the outer side of the battery shell, an air hole is formed in the top of the battery shell, and a waterproof breathable film is arranged on the air hole;

heat-conducting silica gel is coated on the periphery of the soft-package lithium battery pack and the nickel blocks of the PCB wiring board, and the inner wall of the plastic shell is coated with the heat-conducting silica gel;

the battery shell and the heat dissipation ribs are made of modified heat conduction engineering plastic PA6 or PC, the heat conduction coefficient K is 1.8-10W/m.k, the flame retardant rating is UL94-V0, and the battery shell and the heat dissipation ribs are integrally formed in an injection molding mode.

Compared with the prior art, the invention has the following technical effects:

the invention solves the problem of thermal runaway delay burning safety of a PACK module of a soft-package polymer lithium battery, adopts a stacking mode for innovative design in the design of the battery module, adopts battery cells-heat insulation cotton-battery cells which are arranged in sequence, connects the tabs of the battery cells in series or in parallel through the spot welding of a PCB wiring board, and finally fixes the whole battery PACK by using the glue of a battery shell. When the single battery is out of control due to thermal runaway and explodes to cause fire, the heat is isolated and prevented from spreading, the occurrence of thermal runaway caused by adjacent electric cores is prevented, and the danger of fire and fire hazard is avoided. And when the battery pack works normally, heat between the battery cell and the battery cell is not conducted mutually, so that the temperature equalization effect is achieved, the performance of the whole battery pack is improved, and the service life of the whole battery pack is prolonged.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic view of an anti-ignition structure of a soft-packed lithium battery pack according to an embodiment;

fig. 2 is a schematic diagram of bending the positive and negative electrode tabs of the battery cell in an L shape in the first embodiment;

fig. 3 is a schematic diagram illustrating a positive electrode aluminum tab of a battery cell being fixed by being transformed into nickel and being dispensed with glue according to the first embodiment;

fig. 4 is a schematic view of a heat-conducting silica gel at a soft package lithium battery pack point in the first embodiment;

fig. 5 is a schematic structural view of a left and right plastic frame assembled with a soft-package lithium battery according to the first embodiment;

fig. 6 is a schematic structural view of the left and right plastic frames assembled by the soft-packaged lithium battery of the first embodiment, and the left and right plastic frames are fastened by a buckle;

fig. 7 is a schematic bottom structure view of a left and right plastic frame assembled with a soft-packed lithium battery according to the first embodiment;

FIG. 8 is a schematic diagram of a PCB wiring board structure according to the first embodiment;

FIG. 9 is a schematic view of an external structure of a battery-mounting plastic frame according to the first embodiment;

fig. 10 is a schematic diagram of the positive and negative electrode leads of the battery pack of the first embodiment fixed in the slots on the plastic frame and connected to the power terminals on the PCB wiring board;

FIG. 11 is a schematic view of a PCB wiring board of the first embodiment with an insulating sheet attached thereon;

fig. 12 is a first schematic view of a soft-packed lithium battery pack after a delayed burn test according to the present invention;

FIG. 13 is a second schematic view of a soft-packed lithium battery of the present invention after a delayed fire test;

fig. 14 is a third schematic view of a soft-packed lithium battery pack of the present invention after a delayed fire test;

FIG. 15 is a cross-sectional view taken along line A-A of FIG. 14;

fig. 16 is a schematic view of an anti-ignition structure of a soft-packed lithium battery pack according to a second embodiment;

in the figure, 1 is electric core, 2 is the fire prevention double faced adhesive tape, 3 is heat conduction silica gel, 4 is the fine cloth of glass, 5 is right battery plastic frame, 6 is left battery plastic frame, 7 is the insulating piece, 8 is the PCB wiring board, 9 is the EVA bubble cotton, 10 is anodal aluminium utmost point ear, 11 is the negative pole ear, 12 is thermal-insulated cotton, 13 is the nickel piece, 14 is the heat dissipation bleeder vent, 15 is the positive terminal, 16 is the negative terminal, 17 is the steel needle, 18 is the acupuncture electricity core, 19 is soft package lithium cell group, 20 is left sealed plastic shell, 21 is right sealed plastic shell, 22 is the heat dissipation rib, 23 is the seal groove, 24 is the buckle, 25 is the bleeder vent, 26 is waterproof ventilated membrane.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

Example one

As shown in fig. 1 to 11, this embodiment provides a structure for preventing a fire spreading of a lithium-ion battery PACK, wherein a lithium-ion battery PACK module of a lithium-ion battery PACK is composed of a plurality of battery cells 1 connected in series or in parallel, but not limited to the number of the battery cells 1 connected in series in the embodiment of the present invention, and a lithium-ion battery PACK 19 is installed in a battery housing, in this embodiment, the battery housing is a hollow battery plastic frame, the battery plastic frame includes a left battery plastic frame 6 and a right battery plastic frame 5, and the left battery plastic frame 6 and the right battery plastic frame 5 are connected by a buckle 24. Heat insulation cotton 12 is attached between each electric core 1 and the electric core 1, the heat insulation cotton 12 (the heat conductivity coefficient is 0.02W/m.k) has the functions of ultrahigh heat insulation performance, flame retardance, impact resistance and the like, the size of the heat insulation cotton 12 is designed to be slightly larger than that of the electric core 1 (L1 is larger than L2, and D1 is equal to D2), and the heat insulation cotton 12 is attached between all the electric cores 1 and the electric cores 1 of the battery module in this way, as shown in fig. 13 and 15.

In this embodiment, fireproof double-sided tapes 2 are attached to both sides of the thermal insulation cotton 12, so that the thermal insulation cotton 12 and the electrical cores 1 are fixedly attached, and the outermost electrical cores 1 are protected by attaching glass fiber cloth 4 to the surfaces of the two outermost electrical cores 1, as shown in fig. 1.

In this embodiment, the positive aluminum tab 10 of each electrical core 1 is turned to nickel, the turned nickel tab is turned back to seal the groove and is fixed by dispensing, the EVA foam 9 is attached to the groove of each electrical core 1 for buffering, isolating and insulating, the positive aluminum tab 10 and the negative electrode tab 11 are integrated into an L shape and attached to the EVA foam 9, so as to prevent the soft-packaged lithium battery pack 19 from vibrating and falling during use, so as to achieve the effects of buffering, resisting vibration and preventing tab fracture, as shown in fig. 2-3.

In the embodiment, as shown in fig. 8, a PCB wiring board 8 is disposed above the battery cells 1, each tab of the battery cells 1 penetrates through the PCB wiring board 8, the PCB wiring board 8 is attached with a nickel block 13, and the batteries are connected in series or in parallel by spot welding to form a soft-package lithium battery pack 19, and the PCB wiring board 8 is provided with a heat dissipation vent 14 to conduct heat emitted by combustion of the thermal runaway batteries out to reduce heat accumulation; 2 nickel blocks 13 are arranged on the positive electrode and the negative electrode of each battery cell 1, and the number of the nickel blocks 13 is determined according to the number of the batteries connected in series and in parallel; set up nickel piece 13 and make things convenient for the spot welding electrical connection of 1 positive and negative pole ear of electric core, also can be with the conduction of the inside heat of electric core 1 to nickel piece 13 and PCB wiring board 8 on, have certain heat dissipation and module structure firm effect.

In this embodiment, as shown in fig. 11, an insulation sheet 7 is further included, which is attached to the PCB terminal board 8 for insulation of the battery pack and prevention of short circuit.

In the embodiment, the positive and negative leads of the battery pack power supply are connected and fixed in the battery plastic frame wire slot through the positive terminal 15 and the negative terminal 16 on the PCB wiring board 8, so that the leads can be prevented from falling off or the wiring terminal can be prevented from cracking due to vibration and falling. At the position that there is the contact at the head and the afterbody of group battery and shell, fill heat conduction silica gel 3 (as shown in fig. 4) with electric core 1 and the poor recess of thermal-insulated cotton 12 width and closely bond with the heat conduction battery plastic frame that the thermal conductivity (K is 1.8 ~ 10W/m.k) on sheatheeing, fire-retardant rating is UL94-V0, the battery plastic frame divide into two parts, blocks through buckle 24, plays the firm battery module effect of reinforcing and the radiating action.

Carry out two

The embodiment is an improvement on the basis of the first embodiment, and the improvement is as follows: as shown in fig. 16, the battery case is a sealed plastic case, and adopts a full-sealed structure, the sealed plastic case includes a left sealed plastic case 20 and a right sealed plastic case 21, and the left sealed plastic case 20 and the right sealed plastic case 21 are connected by a buckle 24; and is provided with a sealing groove 23 for dispensing and fixing.

Radiating ribs 22 are uniformly distributed on the outer side of the battery shell, a phi 10mm air hole 25 is formed in the top of the battery shell (above the PCB wiring board 8), and a phi 20mm waterproof breathable film 26 is attached to the top of the battery shell; when the battery pack normally works and generates heat, the thermal expansion air can be discharged from the waterproof breathable film 26, the humid air cannot enter the shell, the waterproof grade reaches I P67, and if the battery is abnormally out of control due to heat, the safety air release valve can also be used.

All be coated with heat conduction silica gel 3 around soft packet of lithium cell group 19 on the nickel block 13 of PCB wiring board 8, the inner wall of sealed plastic shell scribbles heat conduction silica gel 3, can play the bonding fixed to with the outside radiating effect of heat conduction casing.

In the embodiment, the material of the battery case can be selected from modified heat-conducting engineering plastics PA6 or PC, etc., and the heat-conducting coefficient K is 1.8-10W/m.k flame retardant grade UL 94-V0; the heat dissipation ribs 22 are made of the above materials, and the plastic shell structure is designed to be formed by injection molding of the heat dissipation ribs 22, so that the strength and the heat dissipation function of the plastic shell can be improved.

According to the invention, the fully charged battery PACK module is arranged in the shell or the outer box, one of the battery PACK module is used as an overcharged battery core 1 to be needled by using the steel needle 17, the thermal runaway combustion or smoke of the battery is triggered in a simulation manner, and the adjacent battery core 1 is not caused to cause the spread of delay combustion, as shown in figures 12-15, the appearance of the adjacent battery core 1 is intact, the voltage of the battery is 4.15V, and the highest temperature of the adjacent battery core 1 is far lower than the temperature born by the thermal runaway of the battery core 1.

In the actual product application, when supposing that any one electric core 1 takes place the thermal runaway burning in the battery module, can avoid adjacent more batteries to be prolonged burn and the danger of explosion and fire, conflagration takes place, solves heat-conduction problem between electric core 1, reduces the heat gathering to make group battery security improve greatly, reduce the safety risk, avoided the loss of life property. The test has obtained good effect, has practicality and novelty.

The principle and the implementation mode of the invention are explained by applying a specific example, and the description of the embodiment is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.

Claims (10)

1. A soft-package lithium battery pack anti-delay structure comprises a plurality of battery cells, wherein the battery cells are arranged in a battery shell; the method is characterized in that: heat insulation cotton is pasted and covered between the adjacent electric cores, and glass fiber cloth is pasted and covered on the surfaces of the two electric cores on the outermost layer and used for protecting the electric cores on the outermost layer; carrying out nickel conversion on the positive aluminum tab of the battery cell, and folding the positive aluminum tab after nickel conversion back to the groove of the battery cell and dispensing and fixing; EVA foam is pasted at the groove of the battery cell, and a positive electrode aluminum tab and a negative electrode tab of the battery cell are pasted on the EVA foam; a PCB wiring board is arranged above the battery cells, and the positive aluminum lug and the negative lug of the battery cells penetrate through the PCB wiring board.

2. The lithium-ion battery pack fire retardant structure of claim 1, wherein: the positive aluminum tab and the negative tab of the battery cell are integrally formed into an L shape and are attached to the EVA foam for preventing the battery pack from vibrating and falling in the using process, and the battery pack plays a role in buffering, resisting vibration and preventing the tab from being broken.

3. The lithium-ion battery pack fire retardant structure of claim 1, wherein: and a nickel block is adhered on the PCB wiring board.

4. The lithium-ion battery pack fire retardant structure of claim 3, wherein: and the positive electrode aluminum lug and the negative electrode lug of the battery cell are connected with the PCB wiring board in a spot welding manner.

5. The lithium-ion battery pack fire retardant structure of claim 4, wherein: the PCB wiring board is provided with heat dissipation air holes, and insulating sheets are pasted on the PCB wiring board.

6. The lithium-ion battery pack fire retardant structure of claim 1, wherein: and the positive and negative leads of the power supply of the soft-package lithium battery pack are connected and fixed in the wire slot of the battery shell through the terminals of the PCB wiring board.

7. The lithium-ion battery pack fire retardant structure of claim 1, wherein: the size of the heat insulation cotton is larger than that of the battery cell, and fireproof double-sided adhesive tapes are pasted on the two sides of the heat insulation cotton.

8. The lithium-ion battery pack fire retardant structure of claim 1, wherein: and the contact positions of the head and the tail of the soft-package lithium battery pack and the battery shell are filled with heat-conducting silica gel at the groove of the battery core and the heat insulation cotton and are tightly bonded with the battery shell.

9. The lithium-on-package battery pack anti-ignition structure according to any one of claims 1 to 8, wherein: the battery casing is the battery plastic frame of fretwork, battery plastic frame includes left battery plastic frame and right battery plastic frame, left side battery plastic frame with right side battery plastic frame connects through the buckle.

10. The lithium-on-package battery pack anti-ignition structure according to any one of claims 1 to 8, wherein: the battery shell is a sealed plastic shell, the sealed plastic shell comprises a left sealed plastic shell and a right sealed plastic shell, the left sealed plastic shell and the right sealed plastic shell are connected through a buckle, and a sealing groove is formed in the joint; radiating ribs are uniformly distributed on the outer side of the battery shell, an air hole is formed in the top of the battery shell, and a waterproof breathable film is arranged on the air hole;

heat-conducting silica gel is coated on the periphery of the soft-package lithium battery pack and the nickel blocks of the PCB wiring board, and the inner wall of the plastic shell is coated with the heat-conducting silica gel;

the battery shell and the heat dissipation ribs are made of modified heat conduction engineering plastic PA6 or PC, the heat conduction coefficient K is 1.8-10W/m.k, the flame retardant rating is UL94-V0, and the battery shell and the heat dissipation ribs are integrally formed in an injection molding mode.

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