CN216793725U - Lithium sheet, lithium battery pole piece, lithium battery cell, lithium battery and electronic equipment - Google Patents

Abstract

The utility model discloses a lithium sheet, a lithium battery pole piece, a lithium battery core, a lithium battery and electronic equipment. The lithium sheet comprises a lithium foil and a protective film; the lithium foil comprises a front surface and a back surface which are oppositely arranged; at least part of the protective film can be dissolved by electrolyte, the protective film is at least used for isolating water, the protective film comprises at least two layers, at least one layer of protective film covers the front side, and at least one layer of protective film covers the back side. The lithium sheet has good protective performance, so that the manufacturing difficulty of the lithium battery pole piece, the lithium battery cell and the lithium battery is reduced, the cost is reduced, and the competitiveness of electronic equipment is improved.

Description

Lithium sheet, lithium battery pole piece, lithium battery cell, lithium battery and electronic equipment

Technical Field

The present disclosure relates to the field of energy storage technologies, and in particular, to a lithium sheet, a lithium battery pole piece, a lithium battery cell, a lithium battery, and an electronic device.

Background

The lithium battery is taken as the most representative energy storage device in the new energy field and occupies an irreplaceable position in a power supply device of electronic equipment. With the miniaturization development of electronic equipment, the space inside the electronic equipment is limited, and how to increase the capacity of the lithium battery and prolong the service time of the electronic equipment in the limited volume becomes an important direction for the development of the lithium battery.

In the related art, some lithium batteries have a large capacity, but coulomb Efficiency (coulomb Efficiency) needs to be improved by using a lithium sheet, so that the manufacturing difficulty and the cost are high.

SUMMERY OF THE UTILITY MODEL

The present disclosure provides a lithium sheet, a lithium battery pole piece, a lithium battery cell, a lithium battery and an electronic device. The lithium sheet has good protective performance, so that the manufacturing difficulty of the lithium battery pole piece, the lithium battery cell and the lithium battery is reduced, the cost is reduced, and the competitiveness of electronic equipment is improved.

The technical scheme is as follows:

according to a first aspect of embodiments of the present disclosure, there is provided a lithium sheet applied to a lithium battery, including a lithium foil and a protective film; the lithium foil comprises a front surface and a back surface which are oppositely arranged; at least part of the protective film can be dissolved by electrolyte, the protective film is at least used for isolating water, the protective film comprises at least two layers, at least one layer of protective film covers the front side, and at least one layer of protective film covers the back side.

The technical scheme provided by the embodiment of the disclosure can have the following beneficial effects:

protect the lithium foil through the protection film, can effectively completely cut off external water droplet or aqueous vapor for the storage requirement and the transportation requirement of this lithium piece can reduce, and then can reduce the storage cost and the cost of transportation of this lithium piece. And when this lithium piece used, at least part of this protection film can be dissolved by the electrolyte, and then need not to get rid of the protection film, can make lithium-ion battery pole piece, lithium-ion battery electricity core and lithium cell, can simplify the manufacturing procedure of lithium-ion battery pole piece, lithium-ion battery electricity core and lithium cell, utilize the protection film to protect simultaneously, the moisture content requirement in the production preparation process is lower (for example can prepare in normal indoor air circumstance or the room air circumstance of drying a little), and then be favorable to reducing the manufacturing degree of difficulty reduction of lithium-ion battery pole piece, lithium-ion battery electricity core and lithium cell.

The technical solution of the present disclosure is further explained below:

in one embodiment, the material of the protective film includes at least one of polymethyl methacrylate, polyvinylidene fluoride, polyacrylonitrile, and polyvinyl chloride.

In one embodiment, the lithium foil has a thickness of 1um to 20 um; and/or the thickness of the protective film is 1 um-10 um.

In one embodiment, the thickness of the lithium foil is greater than the thickness of the protective film.

In one embodiment, a portion of the protective film is soluble to the electrolyte and a portion of the protective film is insoluble to the electrolyte.

In one embodiment, the lithium foil and the protective film are formed by hot-pressing and melting; or the protective film is coated on the front surface and the back surface of the lithium foil; or the protective films are formed on the front surface and the back surface of the lithium foil in a deposition or electrostatic spraying mode.

According to the second aspect of the embodiments of the present disclosure, there is also provided a lithium battery electrode plate, including a current collector, an active body and the lithium plate in any of the above embodiments, the lithium plate is fixedly disposed on the active body through a protection film, and the active body is fixedly disposed on the current collector and disposed between the protection film and the current collector.

The technical scheme provided by the embodiment of the disclosure can have the following beneficial effects:

the lithium battery pole piece adopts the lithium piece, and at least part of the protective film can be dissolved by the electrolyte, so that at least part of the lithium foil is in contact with the electrolyte, and the lithium battery pole piece can be manufactured without removing the protective film, and the manufacturing process of the lithium battery pole piece can be simplified; meanwhile, the protective film is used for protection, so that the requirement on the moisture content in the production and preparation process of the lithium battery pole piece is low (for example, the lithium battery pole piece can be prepared in a normal indoor air environment or a slightly dry indoor air environment), the reduction of the manufacturing difficulty of the lithium battery pole piece is facilitated, the investment on environmental control in the manufacturing process is reduced, and the manufacturing cost of the lithium battery pole piece can be reduced. Meanwhile, the lithium foil is protected by the protective film, so that water drops or water vapor in a storage environment and a transportation environment can be effectively isolated, and the storage cost and the transportation cost of the lithium battery pole piece can be reduced.

The technical solution of the present disclosure is further explained below:

in one embodiment, both sides of the current collector are provided with active bodies and lithium sheets.

In one embodiment, the lithium battery pole piece is a negative pole piece.

In one embodiment, the active material includes at least two of a silicon negative electrode, a graphite negative electrode, and a metal oxide negative electrode.

In one embodiment, the current collector, the active body and the lithium sheet are pressed together by rolling.

According to a third aspect of the embodiments of the present disclosure, there is also provided a lithium battery cell, including a positive plate, a negative plate, and an isolation film disposed between the positive plate and the negative plate, where at least one of the positive plate and the negative plate is the lithium battery pole piece in any of the above embodiments.

The technical scheme provided by the embodiment of the disclosure can have the following beneficial effects:

the battery core of the lithium battery adopts the lithium battery pole piece as at least one of the positive pole piece and the negative pole piece, and is isolated through the isolation film. Because, the lithium foil in the lithium battery pole piece can effectively isolate external water drops and vapor through the protection film, can reduce the manufacturing environment requirement of lithium battery cell, is favorable to reducing lithium battery cell manufacturing cost, also conveniently stores and transports. In addition, at least part of the protective film can be dissolved by the electrolyte, so that at least part of the lithium foil is in contact with the electrolyte, and the lithium battery can be manufactured without removing the protective film, thereby simplifying the manufacturing process of the lithium battery and improving the production efficiency of the lithium battery.

The technical solution of the present disclosure is further explained below:

in one embodiment, the positive plate, the negative plate and the diaphragm are made into the lithium battery cell in a winding mode.

According to a fourth aspect of the embodiments of the present disclosure, there is also provided a lithium battery, including a lithium battery case provided with a sealed cavity, a battery cell, and an electrolyte, wherein the battery cell and the electrolyte are encapsulated in the lithium battery case through the sealed cavity; wherein at least a portion of the protective film is dissolvable by the electrolyte such that at least a portion of the lithium foil is in contact with the electrolyte.

The technical scheme provided by the embodiment of the disclosure can have the following beneficial effects:

the lithium battery adopts the lithium battery pole piece as at least one of the positive pole piece and the negative pole piece, can effectively carry out a lithium supplementing process, improves the coulomb efficiency, and has the advantages of large capacity and high coulomb efficiency. In addition, the lithium foil in the lithium battery pole piece can effectively isolate external water drops and water vapor through the protective film, can reduce the manufacturing environment requirement of the lithium battery, and is favorable for reducing the manufacturing cost of the lithium battery. In addition, at least part of the protective film can be dissolved by the electrolyte, so that at least part of the lithium foil is in contact with the electrolyte, and the lithium battery can be manufactured without removing the protective film, thereby simplifying the manufacturing process of the lithium battery and improving the production efficiency of the lithium battery.

According to a fifth aspect of the embodiments of the present disclosure, there is also provided an electronic device including the lithium battery described above.

The technical scheme provided by the embodiment of the disclosure can have the following beneficial effects:

the lithium battery is adopted by the electronic equipment, the cost of the lithium battery is low, and the lithium battery can have the advantages of large capacity and high coulomb efficiency, so that the electronic equipment has better cost performance and product competitiveness.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

Brief description of the drawingsthe accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure and are not intended to limit the disclosure.

In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an electronic device shown in an embodiment.

Fig. 2 is a schematic structural view of the lithium battery shown in fig. 1.

Fig. 3 is a half-section schematic view of the battery cell shown in fig. 1.

Fig. 4 is a schematic cross-sectional view of a lithium battery pole piece shown in an embodiment.

Fig. 5 is a schematic cross-sectional view of the lithium sheet shown in fig. 4.

Fig. 6 is a schematic diagram of a winding process of a battery cell in an embodiment.

Description of the reference numerals:

10. an electronic device; 100. a housing assembly; 110. an accommodating space; 120. a middle frame; 200. an electricity utilization unit; 300. a lithium battery; 310. a lithium battery case; 311. a closed cavity; 312. a mating end face; 320. an electric core; 321. a tab; 3211. a first connecting body; 322. pole pieces of lithium batteries; 301. a current collector; 302. an active body; 303. a lithium sheet; 3031. a lithium foil; 3001. a front side; 3002. a back side; 3032. a protective film; 320a, a positive plate; 320b, negative plate; 320c, a separation film; 330. an electrolyte; 340. a protection plate; 20. a roll shaft; 30. and (5) rolling the needle.

Detailed Description

For the purpose of making the purpose, technical solutions and advantages of the present disclosure more apparent, the present disclosure will be described in further detail below with reference to the accompanying drawings and detailed description. It should be understood that the detailed description and specific examples, while indicating the scope of the disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.

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 disclosure belongs. The terminology used herein in the description of the disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure.

At present, lithium batteries, which are the most representative energy storage devices in the field of new energy, occupy an irreplaceable position in power supply devices of electronic equipment. Along with the higher and higher requirements of people on the endurance of electronic equipment and the higher and higher requirements on the miniaturization of the electronic equipment, the internal space of the electronic equipment is more and more compact, and the volume for accommodating the lithium battery is limited. How to increase the capacity of the lithium battery and prolong the service time of the electronic equipment in a limited volume becomes an important direction for the development of the lithium battery.

However, the volumetric energy density of lithium ion lithium batteries based on graphite negative electrodes, which are the mainstream in the market, has reached a limit. Currently, the actual gram capacity can reach 450mAh/g after a silica negative electrode is added into a graphite negative electrode, and is improved by about 30 percent compared with pure graphite. Meanwhile, the silicon material has the advantages of environmental friendliness, large reserve and the like, so that the silicon material is considered as a next-generation high-energy-density negative electrode material and is widely researched. However, the silicon-oxygen cathode material has the problem of low coulombic efficiency.

In the related art, a lithium battery partially containing a silicon oxide negative electrode material has a large capacity but requires improvement in coulomb Efficiency by means of a lithium sheet (coulomb Efficiency). However, lithium metal has very high chemical activity and is particularly easy to react with moisture in the air, so that the traditional lithium sheet mode has very strict requirements on the processing environment, and the lithium battery has higher manufacturing difficulty and higher cost.

Based on this, it is necessary to provide a lithium sheet, which has good protective performance and higher safety, can reduce the manufacturing difficulty of lithium battery pole pieces, lithium battery cells and lithium batteries, is favorable for reducing the cost of the lithium battery pole pieces, the lithium battery cells and the lithium batteries, and is favorable for improving the competitiveness of electronic equipment.

For a better understanding of the lithium sheet, the lithium battery pole piece, the lithium battery cell and the lithium battery of the present disclosure, the description is made through the electronic device to which the lithium sheet, the lithium battery pole piece, the lithium battery cell and the lithium battery are applied.

Fig. 1 to 5 are views showing the structure of a lithium battery according to some embodiments. Fig. 1 is a schematic structural diagram of an electronic device shown in an embodiment. Fig. 2 is a schematic structural view of the lithium battery shown in fig. 1. Fig. 3 is a half-section schematic view of the battery cell shown in fig. 1. Fig. 4 is a schematic cross-sectional view of a lithium battery pole piece shown in an embodiment. Fig. 5 is a schematic cross-sectional view of the lithium sheet shown in fig. 4.

In some embodiments of the present disclosure, as shown in fig. 1, an electronic device 10 is provided that includes a lithium battery 300 fabricated using the lithium sheet 303 described above. Thus, the lithium battery 300 has a low cost, and the lithium battery 300 has the advantages of large capacity and high coulomb efficiency, so that the electronic device 10 has a better cost performance and a better product competitiveness.

As shown in fig. 1 to 3, the lithium battery 300 includes a lithium battery case 310 having a sealed cavity 311, a battery cell 320, and an electrolyte 330, wherein the battery cell 320 and the electrolyte 330 are enclosed in the lithium battery case 310 through the sealed cavity 311; the battery cell 320 includes a positive electrode tab 320a, a negative electrode tab 320b, and a separation film 320c disposed between the positive electrode tab 320a and the negative electrode tab 320 b. At least one of the positive electrode tab 320a and the negative electrode tab 320b passes through the lithium battery tab 322 manufactured using the lithium tab 303 described above.

As shown in fig. 4 and 5, the lithium battery electrode sheet 322 includes a current collector 301, an active body 302, and a lithium sheet 303 having the above-described functions. The lithium sheet 303 includes a lithium foil 3031 and a protective film 3032; the lithium foil 3031 includes a front surface 3001 and a back surface 3002 disposed opposite to each other; at least a portion of the protective film 3032 is soluble by the electrolyte 330, such that at least a portion of the lithium foil 3031 contacts the electrolyte 330, the protective film 3032 at least serves to insulate water, the protective film 3032 includes at least two layers, at least one protective film 3032 covers the front surface 3001, and at least one protective film 3032 covers the back surface 3002. The lithium sheet 303 is fixed to the active body 302 through the protective film 3032, and the active body 302 is fixed to the current collector 301 and is disposed between the protective film 3032 and the current collector 301.

Therefore, the lithium foil 3031 is protected by the protective film 3032, and external water drops or water vapor can be effectively isolated, so that the storage requirement and the transportation requirement of the lithium sheet 303 can be reduced, and the storage cost and the transportation cost of the lithium sheet 303 can be further reduced. When the lithium sheet 303 is used, at least part of the protective film 3032 can be dissolved by the electrolyte 330, so that the lithium battery pole piece 322, the lithium battery cell 320 and the lithium battery 300 can be manufactured without removing the protective film 3032, the manufacturing processes of the lithium battery pole piece 322 and the lithium battery 300 can be simplified, meanwhile, the protective film 3032 is used for protection, the requirement on the moisture content in the production and preparation process is low (for example, the lithium battery pole piece 322 and the lithium battery 300 can be prepared in a normal indoor air environment or a slightly dry indoor air environment), and the reduction of the manufacturing difficulty of the lithium battery pole piece 322 and the lithium battery 300 is facilitated.

In addition, it can be understood that, the lithium battery pole piece 322 and the lithium battery cell 320 adopt the lithium sheet 303, since at least part of the protective film 3032 can be dissolved by the electrolyte 330, so that at least part of the lithium foil 3031 can be in contact with the electrolyte 330, and the lithium battery pole piece 322 can be manufactured without removing the protective film 3032, and the manufacturing processes of the lithium battery pole piece 322 and the lithium battery 300 can be simplified; meanwhile, the protection film 3032 is used for protection, so that the moisture content requirement in the production and preparation process of the lithium battery pole piece 322 is low (for example, the lithium battery pole piece can be prepared in a normal indoor air environment or a slightly dry indoor air environment), and further the reduction of the manufacturing difficulty of the lithium battery pole piece 322 is facilitated, the investment of environmental control in the manufacturing process is reduced, and the manufacturing cost of the lithium battery pole piece 322 can be reduced. Meanwhile, the lithium foil 3031 is protected by the protective film 3032, so that water drops or water vapor in a storage environment and a transportation environment can be effectively isolated, and the storage cost and the transportation cost of the lithium battery pole piece 322 and the lithium battery cell 320 can be reduced.

In the lithium battery 300, the lithium battery pole piece 322 is used as at least one of the positive pole piece 320a and the negative pole piece 320b, so that the lithium supplementing process can be effectively performed, the lithium supplementing quality is high, and the coulombic efficiency can be improved, so that the lithium battery 300 has the advantages of large capacity and high coulombic efficiency. In addition, the lithium foil 3031 in the lithium battery pole piece 322 can effectively isolate external water drops and moisture through the protective film 3032, so that the manufacturing environment requirement of the lithium battery 300 can be reduced, and the manufacturing cost of the lithium battery 300 can be reduced. In addition, at least a part of the protective film 3032 can be dissolved by the electrolyte 330, and the lithium battery 300 can be manufactured without removing the protective film 3032, thereby simplifying the manufacturing process of the lithium battery 300 and improving the production efficiency of the lithium battery 300.

In addition, when the lithium sheet 303 is applied to the lithium battery 300 containing the silicon-oxygen negative electrode material, the lithium battery 300 has the characteristics of small volume and large capacity, and has the advantages of high discharge efficiency, low manufacturing cost and the like.

Note that the "protective film 3032 at least functions as a water insulator" includes insulating liquid water, gaseous water, or the like. That is, the protective film 3032 includes hydrophobicity. The protective film 3032 can prevent the lithium foil from reacting with water vapor to cause serious exothermic reaction, and improve the safety of the lithium supplementing process.

The "lithium sheet 303" may be used to supplement lithium to the positive electrode of the battery, or may be used to supplement lithium to the negative electrode of the battery.

As shown in fig. 1, in some embodiments of the present disclosure, the electronic device 10 further includes a housing assembly 100 and a power consumption unit 200, and the lithium battery 300 is used to provide power to the power consumption unit 200.

As shown in fig. 1, the housing assembly 100 is formed with a receiving space 110 for arranging various components of the electronic device 10, and the housing assembly 100 may also function to protect the electronic device 10. At least a part of the power using unit 200 and the lithium battery 300 is disposed in the receiving space 110 of the case assembly 100 and connected with the case assembly 100.

As shown in fig. 1, in some embodiments, the housing assembly 100 includes a middle frame 120, and the lithium battery 300 may be fixed to the middle frame 120.

The material of the housing assembly 100 may be at least one of metal, plastic, ceramic, or glass.

Understandably, the large screen display of the electronic device with the display function, such as a mobile phone or a tablet computer, has become a development trend, and is an important feature for attracting users. And utilize this disclosed lithium cell, can make full use of display screen's area to increase lithium cell capacity. That is, the protection plate can be made longer and narrower along the width direction of the display screen, so that the thickness of the lithium battery is not too large, and the electronic equipment is not influenced to be thinned. That is, when being applied to the electronic equipment with the display function, the lithium battery can meet the requirement of large-screen display, has long endurance performance, and can be thinned.

It should be noted that the electronic devices involved in embodiments of the present disclosure may include handheld devices, in-vehicle devices, wearable devices, computing devices, or other processing devices connected to a wireless modem. Cellular telephones (cellular phones), smart phones (smart phones), Personal Digital Assistants (PDAs), tablet computers, laptop computers (laptops), video cameras, video recorders, cameras, smart watches (smart watches), smart bracelets (smart wristbands), in-vehicle computers, and other electronic devices with imaging capabilities may also be included.

The electricity utilization unit includes, but is not limited to, electrical components such as a CPU, a camera module, a display screen, a sensor, and a speaker.

It should be understood that the installation location of the lithium battery shown in fig. 1 is merely illustrative. And the lithium battery includes, but is not limited to, a soft pack lithium battery or a hard pack lithium battery (e.g., button lithium battery) that can be applied to an electronic device.

As shown in fig. 2, in some embodiments, the lithium battery 300 further comprises a protective sheet 340, and the lithium battery case 310 further comprises a mating end surface 312; the battery cell 320 is arranged in the lithium battery shell 310, the battery cell 320 includes a tab 321, the tab 321 includes a first connector 3211 extending out of the mating end surface 312, and the first connector 3211 is arranged facing the mating end surface 312; the protection plate 340 includes a first plate surface, and the protection plate 340 is stacked on the mating end surface 312 such that the first plate surface faces the mating end surface 312 and is electrically connected to the first connector 3211. In this way, the protective plate 340 is stacked on the mating end surface 312, and the first connector 3211 is also disposed facing the mating end surface 312 and is fixedly connected to the first plate surface of the protective layer. In this way, the tab 321 and the protection plate 340 are stacked in the longitudinal direction of the lithium battery 300, and the space in the width direction of the lithium battery 300 can be fully utilized, so that the tab 321 and the protection plate 340 can be reduced along with the thickness compression of the lithium battery case 310. That is, the lithium battery 300 can be made thinner in a flat design. In addition, the lithium battery 300 can fully utilize the length space and the width space of the electronic device 10 to expand the capacity of the lithium battery 300, so that the electronic device 10 can be thinner while having long endurance performance, thereby being beneficial to light and thin design, further attracting consumers, and being beneficial to improving the product competitiveness.

In an embodiment, this disclosed lithium cell is soft packet of lithium cell, and the material of lithium cell shell is metal complex film to be used for wrapping up electric core, the cooperation terminal surface is the encapsulation terminal surface. Therefore, the lithium battery disclosed by the utility model has the advantages of light weight, large capacity, good safety performance and the like. In addition, by utilizing the packaging mode of the matching end face, the lug and the protection plate, the protection plate can be thinned and narrowed, so that the thickness of the lithium battery can be reduced, and the length of the lithium battery can be reduced by 1.5 mm. Or in the lithium battery bins with the same size, the volume of the battery core can be increased, and the capacity of the lithium battery is further increased.

The metal composite film includes, but is not limited to, an aluminum-plastic composite film.

It should be noted that the protection board of the present disclosure may be formed by at least one of a protection chip (or a management chip), a MOS transistor (triode), a resistor, a capacitor, and a PCB (circuit board).

Alternatively, as shown in fig. 3, the positive electrode tab 320a is provided with a tab 321 which is arranged in a protruding manner, and the negative electrode tab 320b is provided with a tab 321 which is arranged in a protruding manner.

In addition to any of the above embodiments, in some embodiments, the protective film further includes an oxide for isolating the manufacturing environment, such as oxygen, so as to further protect the lithium foil from being safely and reliably stored, transported, and used.

Optionally, in some embodiments, the material of the protective film includes at least one of polymethyl methacrylate, polyvinylidene fluoride, polyacrylonitrile, and polyvinyl chloride. Therefore, the protective film is easy to form on the front surface and the back surface of the lithium foil, can isolate moisture and oxygen, and further improves the transportation and storage safety of the lithium sheet and the lithium battery pole piece 322.

In some embodiments, lithium foil 3031 has a thickness of 1um to 20 um. Therefore, the bending performance of the lithium sheet 303 can be ensured, and the lithium sheet can be rolled and stored.

The specific thickness of the lithium foil 3031 can be selected based on the application, including but not limited to 1um, 2um, 3um, 4um, 5um, 6um, 7um, 8um, 9um, 10um, 11um, 12um, 13um, 14um, 15um, 16um, 17um, 18um, 19um, 20um, and the like.

Lithium foil 3031 includes calendered lithium foil 3031, electrolytic lithium foil 3031, and the like.

In some embodiments, the protective film 3032 has a thickness of 1um to 10 um. In this manner, the protective film 3032 has a sufficient thickness and can be reliably protected.

The specific thickness of the protective film can be selected according to the actual conditions (e.g., thickness of the lithium foil), including but not limited to 1um, 2um, 3um, 4um, 5um, 6um, 7um, 8um, 9um, 10um, etc.

As shown in fig. 4 and 5, in some embodiments, the thickness of the lithium foil is greater than the thickness of the protective film. Therefore, the lithium plate can be ensured to have enough thickness so as to improve the lithium supplementing effect.

In addition to any of the above embodiments, in some embodiments, a portion of the protective film is soluble by the electrolyte and a portion of the protective film is insoluble by the electrolyte. Therefore, when the protective film is dissolved by the electrolyte, the protective film can not be completely dissolved, and part of the protective film can keep the stability of the cell structure and the like; and after part of the protective film is dissolved by the electrolyte, the lithium foil can be contacted with the electrolyte, so that the lithium supplement effect is realized.

In some embodiments, the lithium foil and the protective film are formed by hot-pressing and melting; or the protective film is coated on the front surface and the back surface of the lithium foil; or the protective films are formed on the front surface and the back surface of the lithium foil in a deposition or electrostatic spraying mode. So, can realize the fixed of lithium foil and protection film through multiple means for the lithium foil is reliably protected by the protection film, and the mode of manufacture is more nimble, with the manufacturing of the lithium piece that satisfies different demands.

In some embodiments, the manufacturing process of the lithium sheet may further refer to a manner that the lithium foil and the protective film meet requirements in the manufacturing process of the aluminum-plastic composite film, so as to realize the adhesion of the lithium foil and the protective film, so as to protect the lithium foil.

The material of the "current collector" may be selected according to the electrode properties of the lithium battery electrode plate 322, and may be capable of carrying the active body, so as to realize the transmission of the current generated by the active body.

The current collector can reduce the internal resistance of the lithium battery, and improve the coulombic efficiency, the circulation stability and the rate capability of the lithium battery

As shown in fig. 4, in some embodiments, both sides of the current collector 301 are provided with an active body 302 and a lithium sheet 303. Thus, the active material 302 and the lithium sheet 303 can be supported by making full use of the area and space of the current collector 301, thereby increasing the capacity of the lithium battery 300.

Based on any of the above embodiments, in some embodiments, the lithium battery tab 322 is a negative tab. Therefore, the lithium can be supplemented to the negative plate by utilizing the lithium plate, the performance of the negative plate is improved, and the discharge efficiency of the lithium battery is improved.

Optionally, in some embodiments, the active material includes at least two of a silicon negative electrode, a graphite negative electrode, and a metal oxide negative electrode.

The battery cell manufactured by the lithium battery pole piece 322 may be a winding battery cell or a stacking battery cell.

Based on any of the above embodiments, as shown in fig. 4, in some embodiments, the current collector 301, the active body 302, and the lithium sheet 303 are pressed together by rolling. Therefore, the current collector 301, the active body 302 and the lithium sheet 303 can be combined more tightly by rolling, so that the thickness of the lithium battery pole piece 322 is more uniform, and the lithium battery pole piece is convenient to wind to form a more compact battery cell 320, thereby being beneficial to improving the performance of the lithium battery 300.

As shown in fig. 6, in some embodiments, the winding needle 30 is used to sequentially wind the positive electrode sheet 320a, the isolation film 320c, the negative electrode sheet 320b, and the isolation film 320c, so as to obtain the winding type battery cell 320. So, make this disclosed lithium cell 300 possess outstanding high low temperature performance, charge very rapidly, the overlength life-span, steady high output voltage, sound construction, the shock resistance is strong, superstrong high rate discharge capacity.

It should be noted that the "tab" may be a part of the "lithium battery pole piece", that is, the "tab" and the "other part of the lithium battery pole piece, such as the second connector" are integrally formed; or the tab can be separated from other parts of the lithium battery pole piece, such as the second connector, and then the tab can be manufactured independently and combined with other parts of the lithium battery pole piece, such as the second connector, to form a whole.

Equivalently, the "body" and the "certain part" can be parts of the corresponding "component", i.e., the "body" and the "certain part" are integrally manufactured with other parts of the "component"; the "part" can be made separately from the "other part" and then combined with the "other part" into a whole. The expression "a certain body" or "a certain portion" in the present disclosure is only one example, and is not intended to limit the scope of the present disclosure, so long as the above features are included and the same function is understood to be equivalent to the present disclosure.

In the description of the present disclosure, 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 disclosure and to simplify the description, but are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the present disclosure.

Furthermore, the terms "first", "second", etc. 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," "second," etc. may explicitly or implicitly include at least one of the feature. In the description of the present disclosure, "a plurality" means at least two, e.g., two, three, etc., unless explicitly specifically limited otherwise.

In the present disclosure, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integral; 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 disclosure can be understood as a specific case by a person of ordinary skill in the art.

In the present disclosure, unless otherwise expressly stated or limited, 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 an intermediate. 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 "under," "beneath," and "under" a second feature may be directly under or obliquely under the second 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," "disposed on," "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. Further, when one component is considered to be "fixedly connected" to another component, the two components may be fixed by way of detachable connection, or may be fixed by way of non-detachable connection, such as socket connection, snap connection, integrally formed fixation, welding, etc., which can be realized in the conventional art, and is not cumbersome.

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

The above examples only show several embodiments of the present disclosure, and the description thereof is more specific and detailed, but not construed as limiting the scope of the utility model. It should be noted that, for those skilled in the art, variations and modifications can be made without departing from the inventive concept of the present disclosure, and these are all within the scope of the present disclosure.

Claims (13)

1. A lithium sheet for a lithium battery, comprising:

a lithium foil comprising oppositely disposed front and back sides; and

the protective film at least partially can be dissolved by electrolyte of the lithium battery, the protective film is at least used for isolating water, the protective film comprises at least two layers, at least one layer of protective film covers the front side, and at least one layer of protective film covers the back side.

2. The lithium sheet of claim 1, wherein the lithium foil has a thickness of 1 to 20 um; and/or the thickness of the protective film is 1 um-10 um.

3. The lithium sheet of claim 1, wherein the thickness of the lithium foil is greater than the thickness of the protective film.

4. The lithium sheet of claim 1, wherein a portion of the protective film is soluble by the electrolyte and a portion of the protective film is insoluble by the electrolyte.

5. The lithium sheet according to any one of claims 1 to 4, wherein the lithium foil and the protective film are formed by hot-press melting; or the protective film is coated on the front surface and the back surface of the lithium foil; or the protective film is formed on the front surface and the back surface of the lithium foil in a deposition or electrostatic spraying mode.

6. A lithium battery pole piece, characterized in that, including the current collector, active body and the lithium piece of any one of claims 1 to 5, the lithium piece through the protection film set firmly in the active body, the active body set firmly in the current collector, and set up in the protection film with between the current collector.

7. The lithium battery pole piece of claim 6, wherein both sides of the current collector are provided with the active body and the lithium sheet.

8. The lithium battery pole piece of claim 6, wherein the lithium battery pole piece is a negative pole piece.

9. The lithium battery pole piece of any one of claims 6 to 8, wherein the current collector, the active body and the lithium sheet are pressed together by a rolling process.

10. A lithium battery cell, comprising a positive plate, a negative plate and a diaphragm arranged between the positive plate and the negative plate, wherein at least one of the positive plate and the negative plate is the lithium battery plate of any one of claims 6 to 9.

11. The lithium battery cell of claim 10, wherein the positive electrode sheet, the negative electrode sheet, and the separator are formed into the lithium battery cell by winding.

12. A lithium battery comprising a lithium battery case provided with a sealed cavity, an electrolyte, and the cell of claim 10 or 11, wherein the cell and the electrolyte are encapsulated in the lithium battery case through the sealed cavity;

wherein at least a portion of the protective film is dissolvable by the electrolyte to contact at least a portion of the lithium foil with the electrolyte.

13. An electronic device characterized by comprising the lithium battery according to claim 12.

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