CN218385354U

CN218385354U - Winding core of winding battery

Info

Publication number: CN218385354U
Application number: CN202221926401.6U
Authority: CN
Inventors: 张智京; 贾凯; 张迎霞; 王金龙
Original assignee: Shanghai Electric Guoxuan New Energy Technology Nantong Co ltd
Current assignee: Shanghai Electric Guoxuan New Energy Technology Nantong Co ltd
Priority date: 2022-07-25
Filing date: 2022-07-25
Publication date: 2023-01-24
Anticipated expiration: 2032-07-25

Abstract

The utility model discloses a winding core of a winding battery, the winding core is a double-winding core, the outermost ring of the double-winding core is cut the diaphragm and is fixed on the vertical side surface of the double-winding core through a heat conduction adhesive tape, the area of the heat conduction adhesive tape is 72% -90% of the area of the vertical side surface of the double-winding core, and the heat conduction adhesive tape sequentially comprises an adhesive layer, a substrate layer, a bonding layer and a heat conduction layer from the position close to the double-winding core to the position far away from the double-winding core; the problems of serious heat accumulation in the center of the winding battery and uneven heat distribution of the battery in the prior art are solved; the utility model can rapidly transfer the heat inside the battery to the bottom of the battery with rapid heat dissipation through the combination of the adhesive tape structure and the heat-conducting adhesive tape, thereby improving the heat dissipation speed of the battery and the uniformity of heat distribution from the inside of the battery; and due to the bonding effect of the adhesive tape, the rigidity of the battery can be improved, and the deformation of the battery under high-rate charge and discharge can be relieved.

Description

Winding core of winding battery

Technical Field

The utility model relates to a roll up core of coiling battery.

Background

The lithium iron phosphate battery has the characteristics of long cycle life, high safety, low cost and the like, but the ionic conductivity and the electronic conductivity of the lithium iron phosphate battery are poor, so that the application of the lithium iron phosphate battery in the high-rate field range is limited. The rate capability of the lithium iron phosphate battery can be improved through nanocrystallization and carbon-coated lithium iron phosphate, and the lithium iron phosphate battery is gradually applied to the high-rate field, such as the fields of 12V start-stop power supplies, energy storage UPS power supplies and the like.

With the gradual increase of the level of electrification, the demand of a high-rate battery system is increased, and the circulation of the battery is influenced by the inconsistent problem of the lithium ion battery pack, so that the demand of the high-rate battery system is met by making the capacity of a large monomer. However, as the capacity of the cell increases, a large amount of heat is generated during the charge and discharge of the battery.

Patent publication No. CN108511842A, the purpose of quickly dissipating battery heat is achieved by coating a graphene heat-conducting coating with high thermal conductivity on a battery case. However, as the capacity of the battery increases and the thickness of the battery increases, heat inside the battery cannot be rapidly dissipated, and a difference in temperature between the inside and the outside of the battery may be caused. Patent publication No. CN109980131A uses an insulating film with high thermal conductivity, but the insulating film is wrapped around the outside of the cell, and is not particularly useful for heat transfer inside the cell. The heat accumulation in the center of the battery is serious, the heat distribution of the battery is uneven, and the single cycle performance and the system safety are affected.

SUMMERY OF THE UTILITY MODEL

The utility model overcomes among the prior art battery center heat pile up serious, the inhomogeneous defect of battery heat distribution, provide a roll up core of coiling battery that heat distribution is even, battery capacity retention rate is high, the cyclicity can be good.

The utility model provides a roll up core of winding battery, it is two rolls up the core to roll up the core, two outermost circles of rolling up the core cut the diaphragm and pass through the heat conduction sticky tape to fix on two side of rolling up the core that stands, the area of heat conduction sticky tape does two roll up 72% -90% of the side area that stands of core, the heat conduction sticky tape includes viscose layer, substrate layer, bond line and heat-conducting layer from being close to two roll cores to keeping away from two roll cores in proper order.

Preferably, the distance a between the heat-conducting adhesive tape and the edge of the double-roll core along the X direction is 4% -20% of the size of the vertical side surface of the double-roll core in the X direction.

Preferably, the distance b between the heat-conducting adhesive tape and the edge of the double-winding core along the Y direction is 2% -5% of the size of the vertical side surface of the double-winding core in the Y direction.

Preferably, the heat conducting layer is a graphene sheet or a coating of a heat conducting material of a graphite sheet.

Preferably, the thickness of the heat conductive layer is 5 to 20 μm, preferably 5 to 10 μm.

Preferably, the adhesive layer is a polypropylene layer. The substrate layer and the heat conduction layer are bonded together through the polypropylene bonding layer.

Preferably, the thickness of the adhesive layer is 2 to 5 μm.

Preferably, the substrate layer is a PET layer. The PET substrate layer is the carrier of whole heat conduction sticky tape, provides the support for other functional layers.

Preferably, the thickness of the substrate layer is 20 to 50 μm.

Preferably, the adhesive layer is an acrylic adhesive layer. The acrylic adhesive layer enables the heat-conducting adhesive tape to have the adhesive effect.

Preferably, the thickness of the adhesive layer is 2 to 5 μm.

In the present invention, the double winding core is a double winding core conventionally known in the art, and the size may be, for example, 22.22mm in thickness, 171mm in height, 194.5mm in thickness.

In the present invention, the size of the heat conductive tape may be 152mm (width) × 175mm (length).

The utility model discloses an actively advance the effect and lie in:

the outermost circle of the double-winding-core battery with the winding structure in the prior art is cut off that the diaphragm is fixed in the middle of the battery core by the PET adhesive tape, and the termination adhesive tape of the double-winding-core battery only plays a role in fixing in the battery core. The utility model replaces the traditional double-winding core tail-winding structure with the adhesive tape structure adopted by the utility model, replaces the common PET adhesive tape with the heat-conducting function, and improves the heat conductivity of the heat-conducting adhesive tape by adding the heat-conducting layer on the adhesive tape; through the combination effect of the adhesive tape structure and the heat conducting adhesive tape, the heat in the battery can be quickly transferred to the bottom of the battery with higher heat dissipation, and the heat dissipation speed of the battery and the uniformity of heat distribution are improved from the inside of the battery; moreover, due to the bonding effect of the adhesive tape, the rigidity of the battery can be improved, and the deformation of the battery under high-rate charge and discharge can be relieved; the utility model discloses reform transform the two core of rolling up of present coiling battery and receive tail structure, finally reach the purpose of fixing, heat dissipation and reinforcing electricity core rigidity, improved the performance of battery and the security of system, just the utility model discloses a technical scheme need not to reform transform current processing equipment, can not increase extra cost.

Drawings

Fig. 1 is a schematic view of a double-winding core structure in embodiment 1 of the present invention;

fig. 2 is a schematic view of a structure of a heat-conducting adhesive tape according to embodiment 1 of the present invention;

fig. 3 is a graph showing the results of the rate discharge temperature rise and cycle performance test of the batteries according to examples 1 to 3 and comparative example 1 of the present invention.

Description of reference numerals:

1-double winding core, 2-heat conducting adhesive tape, 3-adhesive layer, 4-base material layer, 5-adhesive layer and 6-heat conducting layer.

Detailed Description

The present invention is further illustrated by way of the following examples, which are not intended to limit the scope of the invention. The experimental methods without specifying specific conditions in the following examples were selected according to the conventional methods and conditions, or according to the commercial instructions.

Example 1

The present embodiment provides a double-winding core 1 suitable for a large-capacity high-rate wound battery, and fig. 1 is a schematic structural view of the double-winding core 1. The specific structure and dimensions are as follows: thickness width height of the double jellyroll 1 is 22.22mm 171mm 194.5mm.

The positive and negative electrode plates for conventional production are used, the diaphragm is a PE ceramic coating diaphragm with the thickness of (12 + 4) mu m produced by Hebei Jinli New energy science and technology Limited, and the winding core is manufactured by using a full-automatic die cutting and winding integrated machine of a lead company without tin. The size of a single naked battery cell is 11.1mm 171mm 194.5mm, after winding is completed, the ending positions of two naked battery cells are fixed by using the heat conduction adhesive tape 2 shown in fig. 2, the heat conduction adhesive tape 2 is fixed on the vertical side surface of the double-winding core 1, the size of the heat conduction adhesive tape 2 is 152mm (width) 175mm (length), the distance a between the heat conduction adhesive tape 2 and the left edge and the right edge of the double-winding core 1 in the X direction is 10.5mm, and the distance b between the heat conduction adhesive tape 2 and the upper edge and the lower edge of the double-winding core 1 in the Y direction is 9.75mm; the adhesive layer 3 in the heat-conducting adhesive tape 2 is an acrylic adhesive layer, the adhesive layer 5 is a polypropylene layer, the base material layer 4 is a PET layer, and the heat-conducting layer 6 is a graphene heat-conducting material coating. After winding is completed, the double-winding core 1 is subjected to the working procedures of assembly, shelling, formation, capacity grading, grading and the like, and finally the manufacturing production process of the battery core is completed.

Example 2

The difference from embodiment 1 is that the heat conductive layer 6 of the heat conductive tape 2 is replaced by the graphene heat conductive layer 6 by a common graphite heat conductive layer 6.

Example 3

The final tape structure is identical to that shown in the patent, but differs from example 1 in that the size of the thermal tape 2 is 141mm 170mm, and the area of the thermal tape 2 is 72% of the area of the vertical side of the double winding core 1.

Example 4

The final tape structure is the same as that shown in the patent, but the difference from the example 1 is that the size of the thermal conductive tape 2 is 157mm by 187mm, and the area of the thermal conductive tape 2 is 90% of the area of the vertical side surface of the double-winding core 1.

Comparative example 1

The difference with embodiment 1 lies in, uses conventional core ending structure, and the ending sticky tape is in the middle of rolling up the core, and the sticky tape width is 10mm, and length is 170mm, and the material is conventional pet sticky tape, and the glue film is acrylic acid.

Effects of the embodiment

The batteries of examples 1 to 4 and comparative example 1 were tested for rate discharge temperature rise and cycle performance by the following methods, and the results are shown in table 1 and fig. 3.

The multiplying power discharge temperature rise test method comprises the following steps:

setting the volume of a battery core, namely placing the double-winding core 1 in a room temperature environment for 2h before testing, performing charge-discharge test (model BAT-NEEFLCT-05600-V008) by using a star cloud high-precision large-current charge-discharge device, charging to 3.65V at constant current and constant voltage with constant 1C current (the current with the rated capacity value is recorded as 1C), setting the cut-off current to be 0.05C for 1h, discharging to 2.0V at the constant 1C current, setting the discharge capacity for 1h, circulating for three times, and recording the average value of the discharge capacity for three times as C0 (Ah);

placing temperature sensing lines, namely adhering a temperature sensing probe on the upper part, the middle part and the bottom of the double-winding core 1 by using a PI high-temperature adhesive tape;

the multiplying power discharge test comprises (1) charging to 3.65V with a constant current and a constant voltage of 1C0, stopping current to 0.05C, standing for 1h, discharging to 2.0V with a constant current of 1C0, and recording temperature data in the process; (2) and (4) repeating the charging step in the step 1, discharging to 2.0V by constant current of 2C0/4C0 respectively, and recording the temperature data in the process.

Table 1 shows comparative data of the rate temperature rise of examples 1 to 4 and comparative example 1. It adopts to see the utility model provides an in the embodiment 1-4 of two core 1 structures of rolling up, its high magnification discharge temperature rise obviously is less than the electric core in the comparative example 1 of conventional structure, and the embodiment 1 multiplying power discharge temperature rise that uses high thermal conductivity graphite alkene coating is less than the embodiment 2 that uses ordinary graphite coating. Comparing example 1, example 3 and example 4, it can be seen that as the area of the thermal conductive tape 2 increases, the rate discharge temperature rise also decreases, but the corresponding cost also increases, and the overall performance of example 1 is most balanced.

The cycle performance test method comprises the following steps:

setting the cell volume, placing the double-winding core 1 in a room temperature environment for 2h before testing, performing charge-discharge test (model BAT-NEEFLCT-05300-V016) by using a high-precision star cloud charge-discharge device, charging to 3.65V at constant current and constant voltage with constant 1C current (current with rated capacity value is recorded as 1C), stopping current at 0.05C, standing for 1h, discharging to 2.0V at constant 1C current, circulating for three times, and recording the average value of three discharge capacities as C1 (Ah)

And (3) testing the cycle performance of the battery cell, namely charging the battery cell to 3.65V at a constant current and a constant voltage of 1C1, setting aside for 1h, discharging the battery cell to 2.0V at a constant current of 4C1, setting aside for 2h, and recording current, voltage, capacity and energy data in the process. The remaining capacity of n cycles was recorded as C1n (Ah), the remaining capacity retention rate was recorded as C (%), and the remaining capacity retention rate was C (%) = C1n/C1 x 100

Fig. 3 is the circulation performance contrast chart of embodiment 1 and comparative example 1, can see and use the utility model discloses a roll up core structure, because it has reduced exothermic temperature rise, has promoted the heat homogeneity of rolling up the core, and then reduce the chemical side reaction of the big multiplying power of battery discharge in-process, finally can obviously improve the circulation performance of electric core.

TABLE 1 COIL MULTIPLE DISCHARGE TEMPERATURE-INCREASE COMPARATIVE TABLE

Claims

1. The utility model provides a roll up core of winding battery, its characterized in that, it is two roll cores (1) to roll up the core, two outermost circles of rolling up core (1) are cut the diaphragm and are fixed on two side of founding of rolling up core (1) through heat conduction sticky tape (2), the area of heat conduction sticky tape (2) does two 72% -90% of rolling up the side area of founding of core (1), heat conduction sticky tape (2) are from being close to two roll cores (1) to keeping away from two roll cores (1) and include viscose layer (3), substrate layer (4), bond line (5) and heat-conducting layer (6) in proper order.

2. Winding core for wound battery according to claim 1, characterized in that the distance a of the heat conducting adhesive tape (2) from the edge of the double winding core (1) along the X direction is 4-20% of the dimension of the standing side of the double winding core (1) in the X direction.

3. Winding core for a wound battery according to claim 1, characterized in that the distance b of the heat conducting adhesive tape (2) from the edge of the double winding core (1) along the Y direction is 2-5% of the dimension of the vertical side surface of the double winding core (1) in the Y direction.

4. Winding core for wound batteries according to claim 1, characterized in that the heat conducting layer (6) is a graphene sheet or a coating of a heat conducting material of graphite sheets.

5. Winding core for a wound battery according to claim 1, characterised in that the thickness of the heat-conducting layer (6) is 5-20 μm.

6. Winding core for wound batteries according to claim 1, characterised in that the adhesive layer (5) is a polypropylene layer.

7. Winding core for wound batteries according to claim 1, characterized in that the thickness of the adhesive layer (5) is between 2 and 5 μm.

8. Winding core for wound batteries according to claim 1, characterized in that the substrate layer (4) is a PET layer.

9. Winding core for wound batteries according to claim 1, characterized in that the thickness of the substrate layer (4) is 20 to 50 μm.

10. Winding core for wound batteries according to claim 1, characterized in that the adhesive layer (3) is an acrylic glue layer; the thickness of the adhesive layer (3) is 2-5 μm.