CN216213633U

CN216213633U - Battery cell, battery and power utilization device

Info

Publication number: CN216213633U
Application number: CN202122485050.1U
Authority: CN
Inventors: 张鑫; 靳超; 吴子睿; 任苗苗; 赵丰刚
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2021-10-15
Filing date: 2021-10-15
Publication date: 2022-04-05
Anticipated expiration: 2031-10-15

Abstract

The application relates to an electric core, a battery and electric equipment, which comprises a shell, wherein the shell is provided with an accommodating cavity, the electric core also comprises a slow release unit arranged in the accommodating cavity, and the slow release unit comprises a porous structure and is stored with a slow release agent; the sealing element is coated on the outer side of the porous structure and is provided with a slow release channel, and the slow release channel is communicated with the porous structure and the outer side of the sealing element; the porous structure can promote the slow release agent to be discharged into the accommodating cavity from the slow release channel under the action of external force. Through setting up the slowly-releasing unit, in the earlier stage of electric core use, the slowly-releasing agent among the porous structure is because inside and outside concentration difference passes through slowly-releasing channel and outwards diffuses, and reached the middle later stage in the use of electric core, accessible external force acts on porous structure, and makes the slowly-releasing agent among the porous structure passively release to the outside, through the mode that initiative slowly-releasing and passive slowly-releasing combined together, can make the content of additive and the whole life cycle of battery suit.

Description

Battery cell, battery and power utilization device

Technical Field

The application relates to the technical field of electrochemical energy storage, in particular to an electric core, a battery and an electric device.

Background

Lithium secondary batteries are widely used in consumer electronics and energy storage and power batteries because of their advantages such as high specific energy, long cycle life, and low self-discharge. With the wide application of lithium secondary batteries, the requirements for the charging rate, the recycling performance and the storage performance of the batteries are also higher and higher.

Generally, the electrolyte of a lithium secondary battery consists of an organic solvent, a lithium salt and an additive, and the content of the additive in the whole life cycle of the battery has a great influence on the performance of the battery, for example, if the content of the additive is too high in the early stage of the use of the battery, the problem of low conductivity and side reaction is caused, and if the content of the additive is low in the later stage of the use, the problem of water jump and sudden increase of gas production and expansion are caused.

However, in the prior art, no solution is available for adapting the content of the additive to the full life cycle of the battery so as to reduce the influence on the performance of the battery.

SUMMERY OF THE UTILITY MODEL

Therefore, it is necessary to provide a battery cell, a battery and a power device, which can adapt the content of the additive to the full life cycle of the battery to improve the performance of the battery, in order to solve the problem that the content of the existing additive cannot adapt to the full life cycle of the battery and the performance of the battery is affected.

The application provides an electric core, which comprises a housin, the casing has the holding chamber, electric core is still including arranging in the slowly-releasing unit of holding intracavity, slowly-releasing unit includes:

a porous structure storing a sustained release agent; and

the sealing element is coated on the outer side of the porous structure and provided with a slow release channel, and the slow release channel is communicated with the porous structure and the outer side of the sealing element;

the porous structure can promote the slow release agent to be discharged into the accommodating cavity from the slow release channel under the action of external force.

Above-mentioned electric core, set up the slowly-releasing unit through the holding chamber at the casing, in the earlier stage that electric core used, the inside additive demand of electric core is less, the slowly-releasing agent concentration in the porous structure is higher, and the concentration of the slowly-releasing agent of slowly-releasing unit outside is lower, because inside and outside concentration difference, make inside slowly-releasing agent through slowly-releasing passageway outdiffusion slowly, this is initiative slowly-releasing process, and reached the middle and later stages in the use of electric core, accessible exogenic action is on porous structure, and make the slowly-releasing agent in the porous structure release to the outside passively, be passive slowly-releasing process promptly.

The actual use concentration of various additives is reduced by combining the active slow release and the passive slow release, the problems of DCR (direct current internal resistance) increase, conductivity reduction and the like caused by high-concentration additives are effectively reduced, the supply amount of various additives is ensured in the middle and later periods of the service cycle of the battery cell, the cycle life and the storage life of the battery cell are effectively prolonged, and therefore the content of the additives can be adapted to the whole life cycle of the battery.

In one embodiment, the porous structure is elastic and can be compressed and deformed under the action of an external force to release the sustained-release agent. The sustained release agent can be released more easily under the action of external force on the porous structure, and the sustained release stability is improved.

In one embodiment, the porous structure is formed by a combination of at least two sub-porous structures, wherein the compression modulus is different between at least two of the sub-porous structures. The slow release speed of the additive can be adjusted, so that the quantity of the additive required by attenuation of different battery cores can be better matched, and the cycle performance and the storage performance are improved.

In one embodiment, the sustained release agent comprises at least two sub sustained release agents with different properties, and the at least two sub sustained release agents with different properties are stored in at least two sub porous structures with different compression moduli in a one-to-one correspondence manner. Different types of additives can be slowly released, and the slow release speed of various additives can be adjusted, so that the quantity of the additives required by different cell attenuations can be better matched, and the cycle performance and the storage performance can be improved.

In one embodiment, at least two of the sub-porous structures are combined in superposition and/or in mixture. The combination mode has simple process and reduces the manufacturing cost of the porous structure.

In one embodiment, the sealing element is provided with a communication hole, and the communication hole forms the slow release channel; and/or

The intercommunicating pore has been seted up on the sealing member, be equipped with the pellicle in the intercommunicating pore, the pellicle forms the slowly-releasing passageway, and can make the slow-releasing agent certainly porous structure to the outside unidirectional flux of sealing member. The slow release agent can be quickly released into the containing cavity through the communicating hole, and the semipermeable membrane can meet the unidirectional slow release of a certain type of slow release agent.

In one embodiment, the communication holes comprise a plurality of communication holes, two adjacent communication holes are arranged at intervals, and the total area of all the communication holes accounts for 1-40% of the total surface area of the sealing element; and/or

The aperture range of each communicating hole is 200 nanometers to 5 millimeters. The slow release speed of different additives can be realized by adjusting the area or the pore size of the communicating pores, and the slow release effect is good.

In one embodiment, the material of the porous structure is one of hydrogel, aerogel or foam. The material is light and convenient, does not react with the electrolyte, and can ensure the reliable release of the sustained release agent.

In one embodiment, the porous structure is made of one of polyethylene, polypropylene, polystyrene, nylon, polycaprolactone, polyethylene terephthalate, polyurethane, gelatin, chitosan, cellulose, and derivatives thereof. The material is light and convenient, does not react with the electrolyte, and can ensure the reliable release of the sustained release agent.

In one embodiment, the seal is a sealing membrane. The resistance to the external force exerted on the porous structure can be reduced, the slow release speed of the porous structure is improved, in addition, the weight of the slow release unit can also be reduced, and further the weight of the battery cell is reduced.

In one embodiment, the material of the sealing element is one of polyethylene, polypropylene, polyvinyl chloride or polyethylene terephthalate. The sealing performance is good, and the electrolyte does not react with the electrolyte.

In one embodiment, the slow release agent comprises an electrolyte additive.

In one embodiment, the slow release agent comprises one of a film forming additive, an anti-overcharge additive, or a flame retardant additive.

In one embodiment, the battery cell further comprises a winding core arranged in the accommodating cavity;

the slow release unit is arranged between the winding core and the inner wall of the shell; or

The roll cores comprise a plurality of roll cores, and the slow release units are arranged between the roll cores and the inner wall of the shell; and/or

The roll up the core and include a plurality ofly, slowly-releasing unit locates adjacent two roll up between the core. The slow release agent stored in the porous structure can be promoted to be passively released by the expansion force of the battery cell, other mechanisms do not need to be additionally arranged to output acting force, and the structure of the battery cell is simplified.

In one embodiment, the sustained release unit is integrated on the housing; and/or

The battery cell further comprises an insulation protection film arranged in the accommodating cavity, and the slow release unit is integrated on the insulation protection film. The battery cell is more miniaturized, and the arrangement form of the slow release unit is changeable, so that the requirements of various battery cells are met.

In another aspect of the present invention, a battery is also provided, which includes the battery cell described above.

Above-mentioned battery and consumer, holding chamber through the casing at electric core sets up the slowly-releasing unit, earlier stage in the electric core use, the inside additive demand of electric core is less, the slowly-releasing agent concentration in the porous structure is higher, and the concentration of the outside slowly-releasing agent of slowly-releasing unit is lower, because inside and outside concentration difference, make inside slowly-releasing agent through slowly-releasing passageway outdiffusion slowly, this is initiative slowly-releasing process, and the middle and later periods of using of electric core have been arrived, accessible exogenic action is on porous structure, and make the slowly-releasing agent in the porous structure release to the outside passively, be the slowly-releasing process passively promptly.

In another aspect of the present invention, an electric device is also provided, which includes the above battery.

Above-mentioned consumer, the holding chamber through the casing at the electric core of battery sets up the slowly-releasing unit, earlier stage in the electric core use, the inside additive demand of electric core is less, the slowly-releasing agent concentration in the porous structure is higher, and the concentration of the outside slowly-releasing agent of slowly-releasing unit is lower, because inside and outside concentration difference, make the slowly-releasing agent of inside diffuse outward slowly through the slowly-releasing passageway, this is initiative slowly-releasing process, and the middle later stage in the use of electric core has been arrived, accessible exogenic action is on porous structure, and make the slowly-releasing agent in the porous structure release to the outside passively, be the slowly-releasing process passively promptly.

Drawings

Fig. 1 is an exploded schematic structure diagram of a battery cell in an embodiment of the present application;

FIG. 2 is a schematic perspective view of a sustained release unit according to an embodiment of the present application;

FIG. 3 is a schematic perspective view of a porous structure according to an embodiment of the present disclosure;

FIG. 4 is a schematic diagram of a side view of a sustained release unit in an active sustained release state according to an embodiment of the present application;

fig. 5 is a schematic cross-sectional structure diagram of a sustained-release unit of a battery cell in a passive sustained-release state in an embodiment of the present application;

fig. 6 is a schematic cross-sectional structure diagram of a battery cell in an embodiment of the present application;

reference numerals:

the battery core 100, the shell 10, the accommodating cavity 11, the slow release unit 20, the porous structure 21, the sub-porous structure 211, the sealing element 22, the slow release channel 221, the winding core 30 and the insulation protection film 40.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is capable of embodiments in many different forms than those described herein and that modifications may be made by one skilled in the art without departing from the spirit and scope of the application and it is therefore not intended to be limited to the specific embodiments disclosed below.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In the description of the present application, it is to be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the present application.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can include, for example, fixed connections, removable connections, or integral parts; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

Furthermore, the drawings are not 1: 1, and the relative dimensions of the various elements in the figures are drawn for illustration only and not necessarily to true scale.

As mentioned in the background of the utility model, the content of the additive has a great influence on the performance of the battery, and for this reason, in the prior art, some solutions have been proposed, such as disposing a lithium supplement capsule inside the battery cell, wherein the lithium supplement capsule comprises a capsule core, a first capsule wall and a second capsule wall, the capsule core stores a lithium salt solution, and the internal core solution can be gradually released during the use of the battery, so as to reduce the side effect of the additive in the battery system, and the additive can act on the battery cell for a long time.

However, the applicant has found that, although the lithium salt can be released in the use of the battery by means of the capsule, the capsule wall of the capsule is formed by compounding two different polymer materials, so that the physical properties of the capsule, such as the release direction and release speed of the lithium salt, cannot be precisely controlled, and thus, the influence of the additive on the battery performance is uncertain, and the content of the additive cannot be adapted to the full life cycle of the battery.

Therefore, it is desirable to provide a battery cell, a battery and an electric device, which can adapt the content of the additive to the full life cycle of the battery.

Fig. 1 shows a schematic exploded structure diagram of a battery cell in an embodiment of the present application, fig. 2 shows a schematic three-dimensional structure diagram of a sustained release unit in an embodiment of the present application, and fig. 3 shows a schematic three-dimensional structure diagram of a porous structure in an embodiment of the present application. For the purpose of illustration, the drawings show only the structures associated with embodiments of the utility model.

Referring to the drawings, an embodiment of the present application provides an electrical core 100, including a casing 10 and a sustained-release unit 20, where the casing 10 has an accommodating cavity 11, and the sustained-release unit 20 is disposed in the accommodating cavity 11. Specifically, the battery cell 100 further includes a winding core 30 and an electrolyte (not shown) disposed in the accommodating cavity 11.

The sustained-release unit 20 includes a porous structure 21 and a sealing member 22, the porous structure 21 stores a sustained-release agent, the sealing member 22 covers the outer side of the porous structure 21, the sealing member 22 is provided with a sustained-release channel 221, the sustained-release channel 221 communicates with the outer sides of the porous structure 21 and the sealing member 22, wherein the porous structure 21 can promote the sustained-release agent to be discharged from the sustained-release channel 221 to the accommodating cavity 11 under the action of external force.

In the embodiment of the present application, the slow release agent includes one of a film forming additive, an overcharge-preventing additive or a flame-retardant additive, and in other embodiments, the slow release agent may also be other kinds of additives or non-additives, which is not limited herein.

It should be noted that the porous structure 21 has a plurality of pores for storing the sustained release agent, and when an external force is applied, the sustained release agent can be forced to be separated from the pores and enter the accommodating cavity 11 through the sustained release channel 221.

Through set up slowly-releasing unit 20 in holding chamber 11 at casing 10, in the earlier stage of electric core 100 use, as shown in fig. 4, the inside additive demand of electric core 100 is less, slowly-releasing agent concentration in porous structure 21 is higher, and the concentration of the outside slowly-releasing agent of slowly-releasing unit 20 is lower, because the concentration difference of inside and outside, make inside slowly-releasing agent slowly outwards diffuse through slowly-releasing passageway 221, this is the initiative slowly-releasing process, and reached electric core 100's middle and later stages of using, as shown in fig. 5, accessible external force is acted on porous structure 21, and make the slowly-releasing agent in porous structure 21 passively release to the outside, be passive slowly-releasing process promptly.

And through the mode that the active slow release is combined with the passive slow release, the actual use concentration of various additives is reduced, the problems of DCR (direct current internal resistance) increase, conductivity reduction and the like caused by high-concentration additives are effectively reduced, in addition, the supply quantity of various additives is ensured in the middle and later periods of the service cycle of the battery cell 100, the cycle life and the storage life of the battery cell 100 are effectively prolonged, and therefore, the content of the additives can be adapted to the whole life cycle of the battery.

Referring to fig. 2 again, in an embodiment of the present application, the sustained release unit 20 is a rectangular block, and in other embodiments, the sustained release unit may also be another shape, such as a cylinder, and may be adaptively changed according to the shape of the space in the accommodating cavity 11, which is not limited herein.

Referring again to fig. 3, in some embodiments, the porous structure 21 is elastic and can be compressed and deformed by an external force to release the sustained release agent. The porous structure 21 is elastic, so that the sustained-release agent can be released more easily under the action of external force applied to the porous structure 21, and the sustained-release stability is improved.

Further, the porous structure 21 is formed by combining at least two sub-porous structures 211, and the compression modulus is different between the at least two sub-porous structures 21. For example, the porous structure 21 may be formed by combining four sub-porous structures 211 of different compressive moduli, or by combining four sub-porous structures 211, wherein two sub-porous structures 211 have a different compressive modulus than the other two sub-porous structures 211. Therefore, the slow release speed of the additive can be adjusted, so that the quantity of the additive required by attenuation of different battery cells 100 can be better matched, and the cycle performance and the storage performance can be improved.

Furthermore, the sustained release agent comprises at least two sub sustained release agents with different properties, and the at least two sub sustained release agents with different properties are stored in the at least two sub porous structures 211 with different compression moduli in a one-to-one correspondence manner. Through the combination of the sub-porous structures 211 with various additives with different properties, different compression amounts of the sub-porous structures 211 can be realized when external force is applied, so that different types of additives are slowly released, the slow release speed of various additives can be adjusted, the number of the additives required by attenuation of different battery cells 100 is better matched, and the cycle performance and the storage performance are further improved. For example, the porous structure 21 may be formed by combining three sub-porous structures 211, each storing a first film-forming additive, a second film-forming additive, and an additive.

In some embodiments, at least two of the sub-porous structures 211 are combined in an overlapping manner or in a mixed manner, and at least two of the sub-porous structures 211 are combined in an overlapping manner and at least two other sub-porous structures 211 are combined in a mixed manner. The combination method has simple process and reduces the manufacturing cost of the porous structure 21. It should be noted that, compared to the manner of stacking combination, the positional relationship between the sub-porous structures 211 of the mixed combination is more disordered and is no longer a single up-down or left-right relationship. For example, the mixed combination may be formed by mixing at least two spherical sub-porous structures 211 with different compression moduli, or may be formed by other mixing methods, which are not limited herein.

In addition, in addition to ensuring reliable release of the sustained release agent, the material of the porous structure 21 is also not chemically reactive with the electrolyte. Therefore, in some embodiments, the material of the porous structure 21 is one of hydrogel, aerogel or foam, and preferably, the material of the porous structure 21 is foam.

It should be further noted that different materials of the porous structure 21 may also meet the requirements of different types of battery cells 100 for slow release speed, and at the same time, cost control may also be implemented.

More specifically, the material of the porous structure 21 is one of polyethylene, polypropylene, polystyrene, nylon, polycaprolactone, polyethylene terephthalate, polyurethane, gelatin, chitosan, cellulose and derivatives thereof.

In some embodiments, to ensure the sealing performance of the sealing member 22, the sealing member 22 is not disposed of a material that chemically reacts with the electrolyte. Specifically, the material of the sealing member 22 is one of polyethylene, polypropylene, polyvinyl chloride, and polyethylene terephthalate.

In some embodiments, the seal 22 is a sealing membrane. The sealing member 22 is provided in a film shape, so that resistance to an external force applied to the porous structure 21 can be reduced, the sustained-release speed of the porous structure 21 can be increased, and the weight of the sustained-release unit 20 and thus the weight of the battery cell 100 can be reduced.

In some embodiments, the sealing member 22 is provided with a communication hole, and the communication hole forms a slow release channel 221. Thus, the sustained-release agent can be rapidly released into the accommodating cavity 11 through the communicating hole. In other embodiments, the sealing member 22 is provided with a communication hole, a semipermeable membrane is arranged in the communication hole, the semipermeable membrane forms a sustained release channel 221, and the sustained release agent can be conducted from the porous structure 21 to the outer side of the sealing member 22 in a unidirectional manner. Therefore, the one-way slow release of a certain type of slow release agent can be met, the non-slow release agent is prevented from entering the porous structure 21 from the outer side of the sealing element 22 through the slow release channel 221, and the cycle performance and the storage performance are further improved. Specifically, the work of the communicating hole may be a circle, a direction, or other irregular shape, and is not limited herein.

Further, the communication holes include a plurality of communication holes, two adjacent communication holes are arranged at intervals, and the total area of all the communication holes accounts for 1% -40% of the total surface area of the sealing member 22. Therefore, the slow release speed of different slow release agents can be realized by adjusting the specific area of the communicating holes, and the slow release effect is good. In some embodiments, the pore size of each communicating pore is in the range of 200 nm to 5 mm, so that the slow release speed of different additives can be realized by adjusting the pore size of the communicating pore, and the slow release effect is good.

As shown in fig. 6, in some embodiments, the slow release unit 20 is disposed between the core 30 and the inner wall of the shell 10, and in other embodiments, when the core 30 includes a plurality of slow release units 20 may be disposed between two adjacent cores 30. In other embodiments, the sustained release unit 20 includes a plurality of cores, at least one of which is disposed between the core 30 and the inner wall of the casing 10, and at least another of which is disposed between two adjacent cores 30. In general, the sustained release unit 20 may be disposed at one or more locations or according to specific needs. As such, the sustained-release unit 20 is enabled to be applied to a variety of battery cells 100.

Referring to fig. 5 again, when the battery cell 100 is in the middle and later periods of use, the thickness of the anode plate in the winding core 30 is continuously increased, the expansion force of the whole battery cell 100 is continuously increased, and the sustained-release unit 20 in the battery cell 100 is subjected to the expansion force, so as to promote the passive release of the sustained-release agent stored in the porous structure 21. On the one hand, the decay rate of electric core 100 is unanimous with the speed that the expansibility increases, the demand speed of all kinds of additives, consequently, has effectively reduced because the DCR that high enriched additive brought increases, the conductivity descends the scheduling problem, in addition at electric core 100 life cycle middle and later stage, has guaranteed the supply capacity of all kinds of additives, has effectively promoted the cycle life, the storage life of electric core. On the other hand, the expansion force of the battery cell 100 is used to promote the sustained-release agent to be passively released, and other mechanisms are not required to be additionally arranged to output acting force, so that the structure of the battery cell 100 is simplified.

In some embodiments, the battery cell 100 further includes an insulating protection film 40 disposed in the accommodating cavity 11, and the sustained-release unit 20 may also be integrated on the insulating protection film 40. The insulating protective film 40 is coated on the outer side of the battery cell 30, and is used for preventing the battery cell 30 from being damaged by friction with the inner wall of the casing 10. In other embodiments, the sustained-release unit 20 may be integrated on the housing 10, and in other embodiments, when the sustained-release unit 20 includes a plurality of units, at least one sustained-release unit 20 is integrated on the insulating protection film 40, and at least another sustained-release unit 20 is integrated on the housing 10. In this way, the form of the sustained-release unit 20 can also be adaptively changed to meet the requirements of various battery cells 100.

In order to verify the cycle performance and DCR performance of the battery cell 100 of the prior art and the present application, the inventors have purposefully performed verification tests:

example 1:

and adopting a high-nickel ternary lithium ion aluminum shell battery cell as a test battery cell.

The sealing member 22 of the sustained-release unit 20 of this embodiment is a rectangular structure with six sides perforated, the total area of the communicating holes accounts for 3% of the total area, the aperture of the communicating holes is 1 nanometer, and the porous structure 21 is formed by stacking three layers of polystyrene foam. The uppermost layer has a compressive modulus of 2MPa for the foam deformation modulus, the middle layer is 4MPa, and the lowermost layer is 6 MPa. The slow release agent filled in the pores is an electrolyte additive, and the three layers of polystyrene foam are respectively stored as vinylene carbonate, fluoroethylene carbonate and lithium bis (oxalato) borate solution with the concentration of 90%. Three sustained release units 20 are arranged in the test electric core and are respectively positioned between the left and right winding cores 30 and the shell 10 and between the two winding cores 30, and the total additive amount accounts for 2 percent of the liquid injection amount.

The production process of the test battery core adopts an industrial production process, and the main steps comprise stirring, coating, rolling, die cutting and splitting, winding, hot pressing, assembling, welding, liquid injection formation, aging, packaging and the like, wherein the electrolyte injected at the later stage does not contain any additive.

Example 2:

the test cell adopted in this embodiment is the same as that in embodiment 1, and the sustained-release unit 20 is different from that in embodiment 1 only in that the pore diameter of the communication hole is 3 nm.

Example 3:

the test cell adopted in this embodiment is the same as that in embodiment 1, and the slow release unit 20 is different from that in embodiment 1 only in that the total area of the communication holes occupies 6% of the total area.

Example 4:

the test cell adopted in the present embodiment is the same as that in embodiment 1, and the sustained release unit 20 is different from that in embodiment 1 only in that the porous structure 21 is formed by stacking three layers of silica aerogel.

Example 5:

the test cell adopted in this embodiment is the same as that in embodiment 1, and the sustained release unit 20 is different from that in embodiment 1 only in that the porous structure 21 is a single layer of silica aerogel.

Example 6:

the test cell adopted in this embodiment is the same as that in embodiment 1, and the sustained release unit 20 is different from that in embodiment 1 only in that there is a single sustained release unit 20 located between two winding cores 30.

Comparative example 1:

in the comparative example, the test cell is the same as that in example 1, but the slow release unit 20 is not provided, and electrolyte additives, namely vinylene carbonate, fluoroethylene carbonate and lithium bis (oxalato) borate solution are respectively filled in the production process of the test cell at the later stage.

Comparative example 2:

this comparative example uses the same test cell as example 1, but without the sustained release unit 20, and no electrolyte additive was added during the test electricity production.

The above examples 1-6 and comparative examples 1 and 2 were tested by the following methods:

1) and (3) carrying out cycle test: after testing the capacity of each group of test battery cells, carrying out 25-0, 0.33C charge-discharge test;

2) the DCR test was performed: and (4) taking each group of test battery cells to test the capacity, discharging to 50% SOC, and testing the internal resistance according to the national standard GB-38031.

The test results are shown in table 1:

TABLE 1

And (4) test conclusion:

1) the higher the additive concentration in the initial electrolyte is, the higher the DCR is, and the use of the slow release unit 20 reduces the internal resistance of the battery core.

2) The cycle performance of the test cell with the sustained release unit 20 is superior to that of the test cell directly added with the additive.

3) The cycle performance of the test cell adopting the porous structure 21 with the multilayer foam structure and the plurality of slow release units 20 is better.

Based on the same inventive concept, the present application also provides a battery, which includes the battery cell 100 described above.

Based on the same inventive concept, the application also provides an electric device which comprises the battery.

The battery core 100, the battery and the electric equipment provided by the embodiment of the application have the following beneficial effects:

through setting up slowly-releasing unit 20 in the holding chamber 11 at casing 10, earlier stage in electric core 100 uses, the inside additive demand of electric core 100 is less, the slowly-releasing agent concentration in porous structure 21 is higher, and the concentration of the outside slowly-releasing agent of slowly-releasing unit 20 is lower, because inside and outside concentration difference, make inside slowly-releasing agent through slowly-releasing passageway 221 outwards diffusion slowly, this is initiative slowly-releasing process, and electric core 100's middle later stage in the use, accessible exogenic action is on porous structure 21, and make the slowly-releasing agent in porous structure 21 release to the outside passively, be passive slowly-releasing process promptly.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. An electric core (100), comprising a casing (10), the casing (10) having a holding cavity (11), characterized in that, the electric core (100) further comprises a slow release unit (20) disposed in the holding cavity (11), the slow release unit (20) comprises:

a porous structure (21) in which a sustained release agent is stored; and

the sealing element (22) is coated on the outer side of the porous structure (21), the sealing element (22) is provided with a slow release channel (221), and the slow release channel (221) is communicated with the outer sides of the porous structure (21) and the sealing element (22);

the porous structure (21) can promote the slow release agent to be discharged into the accommodating cavity (11) from the slow release channel (221) under the action of external force.

2. The electrical core (100) of claim 1, wherein the porous structure (21) is elastic and capable of being compressed and deformed by an external force to release the sustained release agent.

3. The electrical core (100) of claim 2, wherein the porous structure (21) is formed by a combination of at least two sub-porous structures (211), wherein the compression modulus is different between at least two of the sub-porous structures (211).

4. The electrical core (100) of claim 3, wherein the sustained release agent comprises at least two different sub-sustained release agents, and the at least two different sub-sustained release agents are stored in the at least two sub-porous structures (211) with different compression moduli in a one-to-one correspondence.

5. The electrical core (100) of claim 3, wherein at least two of the sub-porous structures (211) are combined in a superimposed and/or mixed combination.

6. The battery cell (100) of claim 1, wherein the sealing member (22) is provided with a communication hole, and the communication hole forms the slow-release channel (221); and/or

The sealing element (22) is provided with a communicating hole, a semipermeable membrane is arranged in the communicating hole, the semipermeable membrane forms the slow release channel (221), and the slow release agent can be conducted from the porous structure (21) to the outer side of the sealing element (22) in a one-way mode.

7. The battery cell (100) of claim 6, wherein the communication holes comprise a plurality of communication holes, two adjacent communication holes are arranged at intervals, and the total area of all the communication holes accounts for 1-40% of the total surface area of the sealing member (22); and/or

The aperture range of each communicating hole is 200 nanometers to 5 millimeters.

8. The battery cell (100) of any of claims 1 to 7, wherein the porous structure (21) is made of one of hydrogel, aerogel or foam.

9. The electrical core (100) according to any of claims 1 to 7, wherein the porous structure (21) is made of one of polyethylene, polypropylene, polystyrene, nylon, polycaprolactone, polyethylene terephthalate, polyurethane, gelatin, chitosan, cellulose, or a derivative thereof.

10. The battery cell (100) of any of claims 1 to 7, wherein the sealing member (22) is a sealing film.

11. The battery cell (100) of any of claims 1 to 7, wherein the sealing member (22) is made of one of polyethylene, polypropylene, polyvinyl chloride, or polyethylene terephthalate.

12. The electrical core (100) of any of claims 1 to 7, wherein the slow release agent comprises an electrolyte additive.

13. The electrical core (100) of claim 12, wherein the slow release agent comprises one of a film forming additive, an anti-overcharge additive, or a flame retardant additive.

14. The battery cell (100) of any of claims 1 to 7, wherein the battery cell (100) further comprises a winding core (30) disposed in the accommodating cavity (11);

the slow release unit (20) is arranged between the winding core (30) and the inner wall of the shell (10); and/or

The winding core (30) comprises a plurality of winding cores, and the slow release unit (20) is arranged between two adjacent winding cores (30).

15. The electrical core (100) according to any of claims 1 to 7, wherein the slow release unit (20) is integrated on the casing (10); and/or

The battery cell (100) further comprises an insulating protective film (40) arranged in the accommodating cavity (11), and the slow release unit (20) is integrated on the insulating protective film (40).

16. A battery, characterized by comprising a battery cell (100) according to any of claims 1 to 15.

17. An electric device comprising the battery of claim 16.