WO2024086993A1 - Battery and electrical device - Google Patents

Abstract

The present application discloses a battery and an electrical device. The battery comprises a shell, and a positive electrode sheet, a negative electrode sheet, and an isolation member which are provided in the shell; a spherical mounting cavity is formed in the shell; the positive electrode sheet has a first convex arc surface and a first bonding surface connected to the first convex arc surface; the negative electrode sheet has a second convex arc surface and a second bonding surface connected to the second convex arc surface; the isolation member is located between the positive electrode sheet and the negative electrode sheet, and the first bonding surface and the second bonding surface are oppositely arranged on the two sides of the isolation member, so that the positive electrode sheet, the isolation member and the negative electrode sheet are assembled to form a spherical structure.

Description

Batteries and electrical devices Technical Field

The present application relates to the field of battery manufacturing, and in particular to a battery and an electrical device.

Background technique

A battery generally includes a housing and a cell disposed in the housing, wherein the cell includes a positive electrode sheet and a negative electrode sheet, and a separator is disposed between the positive electrode sheet and the negative electrode sheet. An electrolyte is injected into the housing to play an electrochemical and conductive role. In existing batteries, due to the uneven distribution of electrolyte in the cell's electrode sheet, lithium ion transmission is blocked during the cycle, resulting in lithium deposition in the cell, which seriously affects the cell's cycle performance and life.

Summary of the invention

The main purpose of this application is to propose a battery, aiming to solve the problem of uneven electrolyte distribution in existing battery cells.

To achieve the above objectives, the battery proposed in this application includes:

A housing, wherein the housing is formed with a spherical mounting cavity;

A positive electrode plate, disposed in the mounting cavity; the positive electrode plate has a first convex arc surface and a first bonding surface connected to the first convex arc surface;

A negative electrode plate is disposed in the mounting cavity; the negative electrode plate has a second convex arc surface and a second bonding surface connected to the second convex arc surface; and

The isolating member is arranged in the installation cavity and is located between the positive electrode sheet and the negative electrode sheet. The first joint surface and the second joint surface are arranged on both sides of the isolating member opposite to each other, so that the positive electrode sheet, the isolating member and the negative electrode sheet are spliced to form a spherical structure.

By adopting a positive electrode plate having a first joint surface and a first convex arc surface and a negative electrode plate having a second joint surface and a second convex arc surface, the positive electrode plate, the separator and the negative electrode plate are combined to form a spherical battery cell, and the spherical battery cell is installed in a spherical installation cavity. After the electrolyte is injected, the force on the battery cell in the spherical cavity is relatively uniform, so that the electrolyte is relatively more evenly distributed in the installation cavity; by adopting a battery cell with a spherical structure, the force inside the battery cell can be relatively more uniform, avoiding the problem of uneven distribution of electrolyte inside the plate due to uneven force on the battery cell, and by improving the uniformity of the electrolyte, the problem of lithium plating caused by uneven distribution of the electrolyte can be avoided.

In some examples, a plurality of receiving holes for receiving electrolyte are provided on the positive electrode plate and/or the negative electrode plate.

By setting the accommodating holes, a certain amount of electrolyte can be accommodated in the accommodating holes. The porous structure formed by the accommodating holes in the positive electrode sheet and/or the negative electrode sheet can provide more transmission paths for lithium ions, improve the electrolyte infiltration effect, and satisfy the ion dynamics during the charge and discharge process, providing a better flow path for lithium ions.

In some examples, the plurality of receiving holes are spaced apart from each other.

Through the spaced distribution of the accommodation hole structure, the positive electrode sheet and/or the negative electrode sheet can form a porous structure, thereby making the lithium ion transmission path inside the positive electrode sheet and/or the negative electrode sheet more diversified and improving the electrolyte infiltration effect.

In some examples, a plurality of the receiving holes are provided on the positive electrode sheet and the negative electrode sheet, and the receiving holes on the positive electrode sheet are arranged corresponding to the receiving holes on the negative electrode sheet.

By making the receiving holes on the positive electrode sheet and the negative electrode sheet consistent, the processing and forming of the positive electrode sheet and the negative electrode sheet can be facilitated. The corresponding receiving holes of the positive electrode sheet and the negative electrode sheet form a space for receiving the electrolyte, and the electrolyte can evenly infiltrate the positive electrode sheet and the negative electrode sheet, so as to provide sufficient electrolyte supply for the positive electrode sheet and the negative electrode sheet.

In some examples, the axial direction of the receiving hole is arranged perpendicular to the first joint surface.

By making the axial direction of the accommodation hole perpendicular to the first joint surface, when processing the positive electrode sheet or the negative electrode sheet, the accommodation hole can be conveniently formed on the positive electrode sheet or the negative electrode sheet at the same time.

In some examples, the inner diameters of the plurality of receiving holes are equal.

By forming the accommodating holes with equal inner diameters, the forming of the accommodating holes can be facilitated.

In some examples, the inner diameter of the receiving hole does not exceed 2 nm.

By making the inner diameter of the accommodating hole not exceed 2nm, a porous structure can be formed in the positive electrode sheet and/or the negative electrode sheet while ensuring the energy density of the positive electrode sheet and/or the negative electrode sheet, thereby ensuring the battery capacity.

In some examples, the plurality of accommodating holes include a first accommodating hole, a second accommodating hole, and a third accommodating hole, and the first accommodating hole, the second accommodating hole, and the third accommodating hole have different hole diameters.

By setting accommodating holes with different apertures, it is possible to conveniently set accommodating holes with different apertures at different thicknesses according to the thickness of the positive electrode sheet and/or the negative electrode sheet, thereby making the positive electrode sheet and/or the negative electrode sheet with varying thickness have a porous structure for accommodating electrolyte.

In some examples, the pore size of the first accommodating hole does not exceed 2 nm, and/or the pore size of the second accommodating hole does not exceed 10 nm, and/or the pore size of the third accommodating hole does not exceed 25 nm.

By limiting the apertures of the first accommodating hole, the second accommodating hole and the third accommodating hole, the positive electrode sheet and/or the negative electrode sheet with varying thickness can have a more reasonable distribution of accommodating holes, so that a porous structure for electrolyte distribution can be formed in both the positive electrode sheet and the negative electrode sheet.

In some examples, the battery further includes:

The first middle shell is embedded in the positive electrode plate, and is provided with a first receiving groove for receiving electrolyte, and the first receiving groove has a first opening extending through the first joint surface; the first middle shell is also provided with a first guide hole connected to the first receiving groove.

By providing the first middle shell and using the first middle shell to contain a certain amount of electrolyte, the electrolyte can seal the first joint surface of the positive electrode plate, thereby replenishing the electrolyte in time to ensure the cycle performance of the battery cell.

In some examples, the outer wall surface of the first middle shell is a convex arc surface.

By making the outer wall surface of the first middle shell a convex arc surface, the relative force distribution between the first middle shell and the positive electrode plate can be made more uniform; the electrolyte close to the outer surface of the first middle shell can also enter the first middle shell more conveniently, thereby avoiding uneven distribution of the electrolyte in the positive electrode plate.

In some examples, the inner wall surface of the first receiving groove is a concave arc surface.

By forming the first receiving groove with a concave arc surface, the electrolyte in the first receiving groove can be distributed relatively evenly, and the electrolyte can flow between the first receiving groove and the positive electrode plate through the first guide hole.

In some examples, the outer wall surface of the first middle shell is a convex arc surface, the inner wall surface of the first middle shell is a concave arc surface, and the first middle shell has an outer circular edge and an inner circular edge located at the first opening, and the outer circular edge and the inner circular edge coincide with the center of the first joint surface.

The outer wall surface and the inner wall surface of the first middle shell form a hollow structure with a roughly hemispherical outline, so that the electrolyte in the first middle shell can be more easily added to the positive electrode plate and lithium deposition caused by uneven force on the positive electrode plate can be avoided.

In some examples, the battery further includes:

The second middle shell is embedded in the negative electrode plate, and is provided with a second containing groove for containing electrolyte, and the second containing groove has a second opening that passes through to the second joint surface; the second middle shell is also provided with a second guide hole connected to the second containing groove.

By providing a second middle shell with a second accommodating groove, a certain amount of electrolyte can be placed in the second accommodating groove so that the electrolyte can seal the second joint surface, thereby avoiding lithium deposition at the negative electrode plate, which helps to improve the safety of the battery.

In some examples, when projected in a plane parallel to the second joint surface, the first opening overlaps the second opening.

The electrolyte required for the first joint surface is supplemented by the electrolyte in the first accommodating tank, and the electrolyte required for the second joint surface is supplemented by the electrolyte in the second accommodating tank, so that the electrolyte on both sides of the isolation member is relatively more uniform to ensure the cycle performance in the battery cell.

In some examples, the first middle shell and the second middle shell are symmetrically distributed on both sides of the isolation member.

By symmetrically arranging the first middle shell and the second middle shell on both sides of the isolating member, the force on the battery cell is relatively more uniform, thereby avoiding the problem of uneven distribution of electrolyte caused by uneven force inside the battery cell.

In some examples, the outer wall surface of the second middle shell is a convex arc surface.

By making the outer surface of the second middle shell a convex arc surface, the electrolyte outside the second middle shell can evenly enter the second containing groove, thereby reducing the influence of the second middle shell on the distribution state of the electrolyte in the negative electrode plate, which helps to ensure the uniformity of the electrolyte.

In some examples, the inner wall surface of the second receiving groove is a concave arc surface.

The container adopts a second containing groove with a concave arc surface, and the second containing groove is formed so that the electrolyte added to the second joint surface by the second containing groove is distributed more evenly.

In some examples, the outer wall surface of the second middle shell is a convex arc surface, the inner wall surface of the second middle shell is a concave arc surface, and the second middle shell has an outer circular edge and an inner circular edge located at the second opening, and the outer circular edge and the inner circular edge coincide with the center of the second joint surface.

The outer wall surface and the inner wall surface of the second middle shell cooperate to form a hollow structure with a roughly hemispherical outline, so that the second middle shell has no effect on the stress condition of the negative electrode plate, thereby avoiding lithium deposition of the negative electrode plate due to uneven stress.

In some examples, the housing includes:

A first shell, wherein the first shell has a hemispherical outer surface, and a hemispherical first cavity and a first opening communicating with the first cavity are concavely disposed in the first shell; one of the positive electrode sheet and the negative electrode sheet is disposed in the first cavity; and

A second shell, wherein the second shell is provided with a hemispherical second chamber and a second opening connected to the second chamber; the other of the positive electrode sheet and the negative electrode sheet is arranged in the second chamber; the first opening is connected to the second opening so that the first chamber is connected to the second chamber to form the installation chamber.

The first shell and the second shell are used to form a shell, which facilitates the installation of the battery cell; because the first shell is formed with a hemispherical outer surface, the force on the first middle shell can be relatively more uniform.

In some examples, the second shell has a hemispherical outer surface, and the outer surface of the first shell and the outer surface of the second shell are spliced together to form a spherical surface.

By making the outer surface of the second shell hemispherical, the second shell cooperates with the first shell to form a spherical structure, which can facilitate the molding of the first shell and the second shell; at the same time, when the battery cell is installed in the shell, the force on the battery cell is relatively uniform.

In some examples, the first housing is detachably connected to the second housing.

By adopting a detachable connection method, the battery can be easily assembled.

In some examples, the battery further includes:

A connecting piece, through which the first shell is connected to the second shell.

By connecting the first shell and the second shell with a connecting piece, the assembly of the two can be facilitated.

In some examples, the connector is connected to the outer wall surfaces of the first shell and the second shell. By connecting the outer wall surfaces of the first shell and the second shell to each other, the first shell and the second shell can be connected to each other while avoiding interference with the spherical battery cell, thereby making the battery cell evenly stressed.

In some examples, the connecting member is ring-shaped; the connecting member is disposed around the outer surface of the housing.

By adopting the annular connecting piece, the first shell and the second shell can be connected to each other, and the first connecting piece and the second connecting piece can be sealed at the same time.

In some examples, the positive electrode sheet is disposed in the first chamber, and the negative electrode sheet is disposed in the second chamber; and the battery further includes:

A first conductive adhesive layer is provided between the first convex arc surface and the inner wall surface of the first cavity;

And/or, a second conductive adhesive layer is disposed between the second convex arc surface and the inner wall surface of the second cavity.

A conductive structure is formed by using the first conductive adhesive layer and the second conductive adhesive layer to conduct current from the battery core.

Based on the above battery examples, the present application also proposes an electrical device, including any of the above batteries. By using the above batteries, damage caused by lithium deposition inside the battery can be avoided, thereby improving the safety of the electrical device.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

FIG1 is a schematic structural diagram of an example of a battery of the present application;

FIG2 is a front view of FIG1 ;

Fig. 3 is a right side view of Fig. 1;

FIG4 is a schematic structural diagram of an example of a housing of the present application;

FIG5 is a schematic structural diagram of another example of a housing of the present application;

FIG6 is a schematic structural diagram of an example of a positive electrode plate of the present application;

FIG7 is a schematic structural diagram of an example of a negative electrode plate of the present application;

FIG8 is a schematic structural diagram of an example of the housing and the positive electrode sheet in the present application in a matching state;

FIG9 is a schematic structural diagram of an example of the housing and the negative electrode sheet in the present application in a matching state;

FIG10 is a schematic structural diagram of another example of the present invention in which the housing and the positive electrode sheet are in cooperation;

FIG11 is a schematic structural diagram of another example of the present invention in which the housing and the negative electrode sheet are in cooperation;

FIG12 is a schematic structural diagram of another example of the present application in which the housing and the positive electrode sheet are in a matching state;

FIG13 is a schematic structural diagram of another example of the present application in which the housing and the negative electrode sheet are in a matching state;

FIG. 14 is a schematic diagram of an embodiment of a battery assembly step of the present application.

Description of Figure Numbers:

Label	name	Label		name
10	shell	11	First Shell
111		First chamber	112	First opening
12	Second shell	121	Second chamber
122	Second opening	13	Connectors
20	Positive electrode	twenty one	The first convex surface
twenty two	First joint surface	twenty three	Accommodation hole
231	The first receiving hole	232	The second receiving hole
233	The third receiving hole	30	Negative electrode
31	The second convex surface	32	Second joint surface
40	Isolation	50	First middle shell
51	First receiving groove	52	First exposure
53	The first guide hole	60	Second middle shell
61	Second accommodating groove	62	Second exposure
63	The second guide hole	The	The

The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings.

Detailed ways

The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

Batteries are widely used in a variety of electrical devices, including but not limited to: mobile phones, portable devices, laptops, electric cars, electric vehicles, ships, spacecraft, electric toys and electric tools, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys and electric airplane toys, etc. Electric tools include metal cutting power tools, grinding power tools, assembly power tools and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers.

Batteries can be divided into disposable batteries and rechargeable batteries according to whether they are rechargeable. The common types of rechargeable batteries are: lead-acid batteries, nickel-metal hydride batteries and lithium-ion batteries. Lithium-ion batteries are currently widely used in pure electric vehicles and hybrid vehicles. The capacity of lithium-ion batteries used for this purpose is relatively low, but they have larger output, charging current, and longer service life.

The battery described in the examples of this application refers to a lithium-ion battery. The battery mentioned in the examples disclosed in this application can be directly or indirectly applied to a suitable electrical device to power the electrical device.

Existing batteries generally include cylindrical batteries, rectangular batteries and soft-pack batteries. The battery includes a shell and a battery cell disposed in the shell. The battery cell includes a positive electrode sheet, a negative electrode sheet and a separator. An electrolyte is injected into the battery shell. Lithium-ion batteries mainly rely on the movement of lithium ions between the positive electrode sheet and the negative electrode sheet to work. In a cylindrical battery, the thin film structure of three layers of material is wound into a cylindrical electrode assembly, while in a rectangular battery, the thin film structure is wound or stacked into an electrode assembly having a roughly rectangular shape.

The materials used for the active materials of the positive and negative electrodes are different. Among the positive electrode materials, the most commonly used materials are lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate and ternary materials (polymers of nickel, cobalt and manganese). Among the negative electrode materials, natural graphite and artificial graphite are currently the main materials, in addition to nitrides, PAS, tin-based oxides, tin alloys, nano-negative electrode materials, and some other intermetallic compounds. As one of the four major components of lithium batteries, negative electrode materials play an important role in improving the capacity and cycle performance of batteries, and are at the core of the midstream of the lithium battery industry. In the structure of lithium batteries, separators are one of the key inner components. The separator materials are mainly polyolefin separators based on polyethylene (PE) and polypropylene (PP). The electrolyte is generally made of high-purity organic solvents, electrolyte lithium salts, additives and other raw materials. The electrolyte plays the role of conducting ions between the positive and negative electrodes of lithium batteries, and is the guarantee for lithium-ion batteries to obtain advantages such as high voltage and high specific energy.

The square shell and cylindrical power batteries currently widely produced in the market have uneven local force on the battery cells during the cycle process, and uneven distribution of electrolyte in the battery cells, which leads to local electrolyte bridge breakage and lithium deposition during the cycle process, resulting in a decrease in cycle capacity and life, and even lithium dendrites piercing the separator, causing short circuit of the positive and negative electrodes, creating safety risks.

In view of the above-mentioned technical problems existing in existing batteries, the present application proposes a battery to solve the problem of safety risks easily arising from uneven force on the battery cells during use of existing batteries.

Please refer to Figures 1, 2 and 3. In one example, a battery is disclosed, which includes a shell 10, a positive electrode sheet 20, a negative electrode sheet 30 and an isolating member 40; the shell 10 is formed with a spherical mounting cavity (not shown in the figure); the positive electrode sheet 20 is arranged in the mounting cavity; the positive electrode sheet 20 has a first convex arc surface 21 and a first joint surface 22 connected to the first convex arc surface 21; the negative electrode sheet 30 is arranged in the mounting cavity; the negative electrode sheet 30 has a second convex arc surface 31 and a second joint surface 32 connected to the second convex arc surface 31; the isolating member 40 is arranged in the mounting cavity and is located between the positive electrode sheet 20 and the negative electrode sheet 30, and the first joint surface 22 and the second joint surface 32 are relatively arranged on both sides of the isolating member 40, so that the positive electrode sheet 20, the isolating member 40 and the negative electrode sheet 30 are spliced to form a spherical structure.

Please refer to FIG. 1 , FIG. 4 and FIG. 5 , a spherical installation cavity is formed inside the housing 10 , and the spherical installation cavity means that the contour of the inner wall surface of the installation cavity is spherical.

Please refer to FIG6 , the positive electrode sheet 20 has a first joint surface 22 and a first convex arc surface 21, and the first joint surface 22 is connected to the first convex arc surface 21, so that the positive electrode sheet 20 forms a structure with an outer contour close to a hemispherical shape. For the convenience of description, the positive electrode sheet 20 is referred to as a hemispherical structure below. The first convex arc surface 21 is the hemispherical surface of the positive electrode sheet 20, and the first convex arc surface 21 faces the inner surface of the installation cavity and is arranged away from the spherical center of the installation cavity; the first joint surface 22 faces the spherical center of the installation cavity.

Please refer to FIG. 7 , the negative electrode sheet 30 has a second joint surface 32 and a second convex arc surface 31, and the second joint surface 32 is connected to the second convex arc surface 31, so that the negative electrode sheet 30 forms a structure with an outer contour close to a hemispherical shape. For the convenience of description, the negative electrode sheet 30 is referred to as a hemispherical structure below. The second convex arc surface 31 is the hemispherical surface of the positive electrode sheet 20, and the second convex arc surface 31 faces the inner surface of the installation cavity and is arranged away from the spherical center of the installation cavity; the second joint surface 32 faces the spherical center of the installation cavity.

The separator 40 is disposed between the positive electrode sheet 20 and the negative electrode sheet 30, and can be used to prevent internal short circuit caused by contact between the positive electrode sheet 20 and the negative electrode sheet 30. The separator 40 can also prevent relatively large molecules from passing through, and allow small charged ions to pass through, which can increase the concentration difference near the positive electrode sheet 20 and the negative electrode sheet 30, which is beneficial to the diffusion of ions, thereby improving the storage efficiency of the battery.

The positive electrode sheet 20 and the negative electrode sheet 30 are respectively arranged opposite to each other on both sides of the isolation member 40, and the first joint surface 22 of the positive electrode sheet 20 and the second joint surface 32 of the negative electrode sheet 30 are arranged opposite to each other, so that the positive electrode sheet 20, the isolation member 40 and the negative electrode sheet 30 are combined to form a spherical battery cell structure.

The shell 10 is filled with electrolyte, which infiltrates the positive electrode sheet 20 and the negative electrode sheet 30 to conduct lithium ions. In this example, the battery may also include a conductive glue disposed on the inner wall surface of the mounting cavity, which is used to conduct electricity to conduct the current of the battery cell; the battery may also include other functional components, which can be referred to the prior art and will not be described one by one.

Please refer to Figures 8 and 9. The battery cell structure is spherical, and the outer shell 10 is formed with a spherical installation cavity concentric with the battery cell structure. After the battery cell structure is in the installation cavity, the inner wall of the installation cavity can support the outer surface of the battery cell. Since the battery cell structure and the installation cavity structure are both spherical, the battery cell structure is supported by the inner wall surface of the installation cavity at any position. At the same time, the spherical inner wall surface of the installation cavity is matched with the battery cell with a spherical outer wall surface, so that the force at each position on the surface of the battery cell structure is relatively uniform, and it is not easy for the battery cell to be deformed due to uneven local force. When an external force acts on the outer shell 10, since the spherical battery cell cooperates with the installation cavity, the external force can act on the battery cell in a dispersed manner, thereby avoiding the problem of electrolyte extrusion caused by uneven local force on the battery cell, and avoiding uneven distribution of electrolyte in the battery cell.

By improving the uniformity of the electrolyte in the battery cell, the electrolyte can fully infiltrate the positive electrode sheet 20 and the negative electrode sheet 30 during the electrochemical reaction, avoiding the electrolyte bridge breaking phenomenon caused by uneven electrolyte, and further avoiding the lithium precipitation phenomenon. By improving the uniformity of electrolyte distribution, the internal short circuit caused by the continuous growth of lithium dendrites at the second joint surface 32 and piercing the separator 40 is prevented.

During the charging and discharging process of the battery, the electrode sheet will expand due to the cyclic embedding/de-embedding reaction of lithium ions on both sides of the negative electrode and the positive electrode. Since the spherical installation cavity is used to limit the spherical battery cell structure, the force acting on the battery cell structure can be relatively more dispersed and uniform, thereby preventing the positive electrode sheet 20 and the negative electrode sheet 30 from being squeezed out in large quantities due to the unevenly distributed expansion force, further avoiding the problem of insufficient local electrolyte inside the positive electrode sheet 20 and the negative electrode sheet 30, and preventing the problem of lithium ion transmission being hindered during the cycle, thereby preventing lithium plating from occurring in the battery cell, which helps to extend the cycle performance and life of the battery cell.

When the battery is charged, lithium ions are extracted from the positive electrode and diffused in the electrolyte to the second joint surface 32, and then embedded in the negative electrode plate 30. Taking the graphite negative electrode as an example, when the negative electrode potential drops to 200-65mV vs.Li+/Li, the lithium insertion process occurs; as the charging continues, the negative electrode potential drops below 0V vs.Li+/Li, that is, the lithium deposition side reaction occurs, and at this time, the lithium deposition side reaction of the negative electrode and the lithium insertion reaction proceed simultaneously.

When the force on the battery cell is uneven, the gradient formed inside the battery causes the lithium deposition side reaction to proceed at different rates at various points on the negative electrode surface, thereby depositing an uneven lithium layer. When the local temperature of the second joint surface 32 of the negative electrode plate 30 is low, the state of charge is high, and the current density is high, the lithium deposition side reaction tends to proceed rapidly at the second joint surface 32, causing more serious lithium deposition than other areas. In this example, by making the force on the battery cell more uniform, the lithium deposition side reaction in the battery cell is avoided. By reducing the lithium deposition side reaction, the consumption of electrolyte can be reduced, thereby slowing down the capacity decay rate of the battery.

Because the force on the battery cell is more evenly distributed, the electrolyte is relatively evenly distributed inside the battery cell, which can avoid thermal runaway inside the battery, further prevent gassing and melting of metallic lithium, and prevent water and oxygen in the air from reacting with metallic lithium, further preventing the battery from burning or even exploding.

In some examples, the outer surface of the housing 10 is a spherical surface, so that the overall strength of each position of the housing 10 is the same, and the outer contour of the battery is a spherical structure. In some examples, the installation cavity of the housing 10 is a spherical cavity, and the outer contour of the housing 10 can be a rectangular parallelepiped, cylindrical, or other structures.

Please refer to FIG. 10 and FIG. 11 , in some examples, a plurality of receiving holes 23 for receiving electrolyte are formed on the positive electrode sheet 20 and/or the negative electrode sheet 30 .

The receiving hole 23 is used to contain electrolyte to form a transmission channel for lithium ions to flow, promote the circulation of lithium ions, and allow the electrolyte to fully infiltrate the positive electrode sheet 20 and/or the negative electrode sheet 30 .

In this example, a plurality of the receiving holes 23 are provided in the positive electrode plate 20. By providing the receiving holes 23, a porous structure is formed in the positive electrode plate 20, and the electrolyte enters the receiving holes 23, which can provide a transmission channel for lithium ions. When the positive electrode plate 20 is subjected to an external force and causes the electrolyte to be squeezed out, the receiving holes 23 can be used as a space to temporarily accommodate the electrolyte; the electrolyte accommodated in the receiving holes 23 can re-enter the interior of the positive electrode plate 20, thereby fully infiltrating the positive electrode plate 20, and preventing the problem of uneven distribution of the electrolyte in the positive electrode plate 20. Since the receiving holes 23 form a porous structure in the positive electrode plate 20, the anti-extrusion deformation ability of the positive electrode plate 20 is relatively improved, and the expansion amplitude of the positive electrode plate 20 during the embedding/de-embedding reaction can be further reduced, thereby helping to improve the problem of local electrolyte unevenness.

In this example, a plurality of the receiving holes 23 are provided in the negative electrode plate 30. By providing the receiving holes 23 in the negative electrode plate 30, a certain amount of electrolyte can be accommodated in the receiving holes 23, so that there can be sufficient electrolyte at the second joint surface 32 of the negative electrode plate 30, so as to reduce the lithium deposition at the second joint surface 32, thereby avoiding the short circuit caused by the lithium dendrites at the second joint surface 32 piercing the separator 40 after continuous growth. The electrolyte contained in the receiving holes 23 can more evenly infiltrate the negative electrode plate 30 to prevent the electrolyte in the negative electrode plate 30 from being uneven. Since the receiving holes 23 can form more lithium ion transmission channels in the negative electrode plate 30, the lithium ion kinetic effect during electrolyte infiltration and charging and discharging can be improved. When the electrolyte is uneven locally in the negative electrode plate 30, the electrolyte contained in the receiving holes 23 can be used to replenish the uneven electrolyte position, thereby ensuring the cycle performance of the battery cell. Since the accommodating hole 23 forms a porous structure in the negative electrode plate 30, the anti-extrusion deformation capability of the negative electrode plate 30 is relatively improved, which can further reduce the expansion amplitude of the negative electrode plate 30 during the embedding/de-embedding reaction, thereby helping to reduce the problem of local electrolyte unevenness.

In this example, a receiving hole 23 is provided on both the positive electrode sheet 20 and the negative electrode sheet 30. A certain amount of electrolyte is contained in the receiving hole 23, so that both the positive electrode sheet 20 and the negative electrode sheet 30 can be fully infiltrated, and a more sufficient lithium ion transmission channel is formed in the positive electrode sheet 20 and the negative electrode sheet 30; when the electrolyte is insufficient locally, it is replenished in time, thereby ensuring the cycle performance of the battery cell.

In some examples, the positions of the receiving holes 23 of the positive electrode sheet 20 and the negative electrode sheet 30 are the same. In some examples, the apertures of the receiving holes 23 of the positive electrode sheet 20 and the negative electrode sheet 30 are the same. In some examples, the apertures and positions of the receiving holes 23 of the positive electrode sheet 20 and the negative electrode sheet 30 are the same, and when manufacturing the positive electrode sheet 20 and the negative electrode sheet 30, molds of the same specifications can be used for processing and forming.

Further, in some examples, the accommodation hole 23 is a through hole or a countersunk hole perpendicular to the first joint surface 22. When manufacturing the positive electrode sheet 20, a core perpendicular to the first joint surface 22 can be provided, and when the mold is opened, the core is pulled out to form the accommodation hole 23. In some examples, the accommodation hole 23 is an irregular hole structure, so that an irregular honeycomb structure is formed in the positive electrode sheet 20 and/or the negative electrode sheet 30.

Please continue to refer to FIG. 10 and FIG. 11 . In some examples, a plurality of receiving holes 23 are distributed at intervals.

The multiple accommodating holes 23 may be regularly distributed holes or may not have a fixed distribution pattern. Taking the accommodating holes 23 shown in FIG. 10 as an example, at least some of the accommodating holes 23 have openings that pass through the first joint surface 22, and the accommodating holes 23 are dispersedly distributed with the geometric center of the first joint surface as the center. The multiple accommodating holes 23 may also be distributed in a ring array with the first joint surface 22 as the center.

By distributing the plurality of accommodating holes 23 at intervals, the accommodating holes 23 can form spaces for accommodating electrolyte at multiple locations, so that the electrolyte can more fully infiltrate the positive electrode sheet 20 and/or the negative electrode sheet 30. By using the accommodating holes 23 distributed at intervals, the positive electrode sheet 20 and/or the negative electrode sheet 30 form a honeycomb-like structure, so that the compressive resistance and deformation resistance are stronger.

In some examples, a plurality of receiving holes 23 are provided on both the positive electrode sheet 20 and the negative electrode sheet 30 , and the receiving holes 23 on the positive electrode sheet 20 are arranged corresponding to the receiving holes 23 on the negative electrode sheet 30 .

The receiving holes 23 on the positive electrode sheet 20 are consistent with the receiving holes 23 on the negative electrode sheet 30, which means that at least one of the positions, numbers, diameters and depths of the receiving holes 23 on the positive electrode sheet 20 and the negative electrode sheet 30 are consistent.

By making the receiving hole 23 on the positive electrode sheet 20 consistent with the receiving hole 23 on the negative electrode sheet 30, the compressive strength and the amount of electrolyte contained in the positive electrode sheet 20 and the negative electrode sheet 30 can be made closer, thereby ensuring the circulation of the electrolyte and improving the safety of the battery; at the same time, when processing the positive electrode sheet 20 and the negative electrode sheet 30, the same mold can be used for processing, thereby facilitating the processing and molding of the product.

In some examples, the receiving hole 23 on the positive electrode plate 20 and the receiving hole 23 on the negative electrode plate 30 are disposed at corresponding positions on both sides of the isolation member 40 .

The receiving holes 23 on the positive electrode sheet 20 and the receiving holes 23 on the negative electrode sheet 30 are arranged in positions corresponding to each other on both sides of the separator 40. For any receiving hole 23 on the positive electrode sheet 20, a corresponding receiving hole 23 is arranged at a corresponding position on the negative electrode sheet 30. The apertures of the receiving holes 23 on the positive electrode sheet 20 and the corresponding receiving holes 23 on the negative electrode sheet 30 may be equal or unequal. When the apertures of the receiving holes 23 on the positive electrode sheet 20 and the corresponding receiving holes 23 on the negative electrode sheet 30 are equal, and when the positions and depths are the same, the positive electrode sheet 20 and the negative electrode sheet 30 are symmetrically arranged on both sides of the separator 40.

Since the accommodating hole 23 on the positive electrode sheet 20 corresponds to the accommodating hole 23 on the negative electrode sheet 30, the deformation resistance of the positive electrode sheet 20 and the negative electrode sheet 30 can be closer. When the battery is subjected to external force, the compressive resistance of the positive electrode sheet 20 and the negative electrode sheet 30 is close, so that the battery cell is not easy to produce local deformation.

In some examples, the axial direction of the receiving hole 23 is perpendicular to the first joint surface 22 .

During the molding process of the positive electrode sheet 20 and/or the negative electrode sheet 30, the accommodating hole 23 can be conveniently molded synchronously. Taking the production of the positive electrode sheet 20 as an example, since the first joint surface 22 is a plane and the first convex arc surface 21 is an arc surface, a core is installed on the surface of the mold cavity corresponding to the first joint surface 22. After the positive electrode sheet 20 is molded, the mold can be opened in a direction perpendicular to the first joint surface 22 during demolding, and the core can be taken out in a direction perpendicular to the first joint surface 22, thereby avoiding damage to the positive electrode sheet 20 during mold opening.

In some examples, the depths of the receiving holes 23 are equal. In some examples, the depths of the receiving holes 23 are not equal. Since both the positive electrode sheet 20 and the negative electrode sheet 30 are hemispherical structures, the depth of the receiving hole 23 can be increased in the area where the thickness of the positive electrode sheet 20 and/or the negative electrode sheet 30 is larger, and the depth of the receiving hole 23 can be reduced in the area where the thickness of the positive electrode sheet 20 and/or the negative electrode sheet 30 is smaller.

In some examples, the receiving hole 23 on the positive electrode plate 20 has an opening extending through the first joint surface 22 to replenish the electrolyte at the first joint surface 22. In some examples, the receiving hole 23 on the negative electrode plate 30 has an opening extending through the second joint surface 32 to replenish the electrolyte at the second joint surface.

In some examples, the inner diameters of the plurality of accommodating holes 23 are equal to facilitate the molding of the accommodating holes 23 and simplify the processing of the mold. After the positive electrode sheet 20 and/or the negative electrode sheet 30 are formed, a more uniform accommodating space can be formed in the positive electrode sheet 20 and/or the negative electrode sheet 30, which also helps to improve the anti-deformation performance of the positive electrode sheet 20 and the negative electrode sheet 30.

Further optionally, the inner diameter of the accommodating hole 23 does not exceed 2nm, so that the accommodating hole 23 can be used to accommodate the electrolyte, and the accommodating hole 23 does not occupy too much space in the positive electrode sheet 20 and/or the negative electrode sheet 30, thereby ensuring that the energy density of the positive electrode sheet 20 and the negative electrode sheet 30 reaches a preset level. The accommodating hole 23 can be a through hole or a countersunk hole of 1nm, 1.3nm, 1.5nm, 1.8nm or 2nm.

Please refer to FIG. 10 and FIG. 11. In some examples, the plurality of accommodating holes 23 include a first accommodating hole 231, a second accommodating hole 232 and a third accommodating hole 233. The apertures of the first accommodating hole 231, the second accommodating hole 232 and the third accommodating hole 233 are different. Among them, the apertures of the first accommodating hole 231, the second accommodating hole 232 and the third accommodating hole 233 gradually increase. By using accommodating holes 23 with different apertures to cooperate with each other, spaces of different sizes for accommodating electrolyte are formed on the positive electrode sheet 20 and/or the negative electrode sheet 30, so that the distribution of the electrolyte is relatively dispersed, and the electrolyte can fully infiltrate the positive electrode sheet 20 and/or the negative electrode sheet 30 material. At the same time, by using accommodating holes 23 with different apertures, the positive electrode sheet 20 and/or the negative electrode sheet 30 can form an irregular honeycomb structure, thereby improving the anti-deformation performance of the positive electrode sheet 20 and/or the negative electrode sheet 30.

In some examples, the first accommodating hole 231, the second accommodating hole 232 and the third accommodating hole 233 are arranged at intervals from each other. The first accommodating hole 231, the second accommodating hole 232 and the third accommodating hole 233 can be spaced and distributed according to a certain rule. Taking the positive electrode plate 20 as an example, the distribution of the first accommodating hole 231, the second accommodating hole 232 and the third accommodating hole 233 is related to the volume, material, energy density and other factors of the positive electrode plate 20. For example, the first accommodating hole 231, the second accommodating hole 232 and the third accommodating hole 233 are all distributed in a ring shape with the center of the first joint surface 22 as the center, or the third accommodating hole 233, the second accommodating hole 232 and the first accommodating hole 231 are distributed divergently from the inside to the outside. In this example, the first accommodating hole 231, the second accommodating hole 232 and the third accommodating hole 233 can also be spaced and distributed on the positive electrode plate 20 in other ways.

In some examples, the first accommodating hole 231, the second accommodating hole 232, and the third accommodating hole 233 on the positive electrode sheet 20 may be through holes or countersunk holes penetrating to the first joint surface 22, and the first accommodating hole 231, the second accommodating hole 232, and the third accommodating hole 233 on the negative electrode sheet 30 may be through holes or countersunk holes penetrating to the second joint surface 32. The number, position, and/or aperture of the accommodating holes 23 on the positive electrode sheet 20 and the accommodating holes 23 on the negative electrode sheet 30 may be the same or different.

Further, in some examples, the aperture of the first receiving hole 231 does not exceed 2nm, the first receiving hole 231 is a small hole opened on the positive electrode plate 20 and/or the negative electrode plate 30, and the first receiving hole 231 can be a through hole or a countersunk hole of 1nm, 1.3nm, 1.5nm, 1.8nm or 2nm. In some examples, the aperture of the second receiving hole 232 does not exceed 10nm, the aperture of the second receiving hole 232 is larger than the aperture of the first receiving hole 231, and the second receiving hole 232 can be a through hole or a countersunk hole of 3nm, 5nm, 7nm, 8nm or 10nm; in some examples, the aperture of the third receiving hole 233 does not exceed 25nm, the aperture in the third receiving hole 233 is larger than the second receiving hole 232, and the third receiving hole 233 can be a through hole or a countersunk hole of 12nm, 15nm, 18nm, 20nm, 23nm or 25nm.

By limiting the apertures of the first accommodating hole 231, the second accommodating hole 232 and the third accommodating hole 233, the accommodating holes 23 with different apertures are matched with each other to accommodate more electrolyte without excessively affecting the energy density of the electrode, which helps to improve the safety performance of the battery while reducing the impact on the battery capacity.

Please refer to Figure 12, the battery also includes a first middle shell 50 embedded in the positive electrode plate 20, the first middle shell 50 is provided with a first receiving groove 51 for receiving electrolyte, the first receiving groove 51 has a first opening 52 that passes through the first joint surface 22; the first middle shell 50 is also provided with a first guide hole 53 connected to the first receiving groove 51.

The first middle shell 50 has a first accommodating groove 51 inside, so that a hollow structure capable of accommodating electrolyte is formed inside the first middle shell 50, and the first opening 52 is connected to the first accommodating groove 51, so that the electrolyte in the first accommodating groove 51 can flow outward. The first opening 52 penetrates the first joint surface 22, which means that the first accommodating groove 51 is connected to the side of the first joint surface facing the isolation member 40 through the first opening 52.

The first guide hole 53 is a through hole connecting the outside of the first middle shell 50 and the first containing groove 51, so that the electrolyte in the positive electrode plate 20 can enter the first containing groove 51 through the first guide hole 53. The first guide hole 53 can be a straight hole or an inclined hole evenly distributed on the first middle shell 50, or a through hole of other shapes.

When the positive electrode sheet 20 is squeezed, the electrolyte in the positive electrode sheet 20 can enter the first receiving groove 51 through the first guide hole 53, and a certain amount of electrolyte is stored in the first receiving groove 51, so that the electrolyte can be replenished to the first joint surface 22 through the first opening 52. The electrolyte can also be replenished into the positive electrode sheet 20 again through other first guide holes 53 to improve the problem of uneven electrolyte caused by the positive electrode sheet 20 being squeezed. When injecting electrolyte into the battery, part of the electrolyte can enter the first receiving groove 51 through the first guide hole 53, so that a certain amount of electrolyte can be stored in the first middle shell 50. When necessary, the electrolyte in the first receiving groove 51 can be replenished to the position of the separator 40 through the first opening 52. The shape of the outer surface of the first middle shell 50 can be hemispherical or other shapes, and the shape of the inner surface of the first middle shell 50 can be consistent with or inconsistent with the shape of the outer surface.

In some examples, the positive electrode plate 20 is provided with the accommodation hole 23 described in the above example, and the first flow guide hole 53 of the first middle shell 50 may be connected to the accommodation hole 23 or may not be connected to the accommodation hole 23 .

In some examples, the number of the first middle shell 50 is multiple, and the multiple first middle shells 50 are distributed at intervals. By providing multiple first middle shells 50, multiple cavities for accommodating electrolyte can be formed at the position of the positive electrode plate 20 close to the separator 40 to replenish the electrolyte at the position of the first joint surface 22. Further, the multiple first middle shells 50 can be distributed in a ring shape with the center of the first joint surface 22 as the center. In some examples, the geometric center of the first opening 52 of the first middle shell 50 coincides with the center of the first joint surface 22.

In some examples, the outer wall surface of the first middle shell 50 is a convex arc surface. When the positive electrode sheet 20 is acted upon by an external force, the force exerted on the positive electrode sheet 20 is transmitted to the first middle shell 50, and the positive electrode sheet 20 is also subjected to a reaction force from the first middle shell 50. By forming a convex arc surface, the reaction force exerted by the outer surface of the first middle shell 50 on the positive electrode sheet 20 is relatively more uniform, thereby avoiding unnecessary deformation of the portion of the positive electrode sheet 20 where the first middle shell 50 is embedded.

In some examples, the inner wall surface of the first receiving groove 51 is a concave arc surface. When the electrolyte flows along the inner wall surface of the first receiving groove 51 in the first receiving groove 51, the flow direction of the electrolyte along the arc surface can be more dispersed, so that the electrolyte can flow to the first joint surface 22 in a dispersed manner, so that the electrolyte can more fully infiltrate the positive electrode plate 20. Further, in some examples, the outer wall surface of the first middle shell 50 is a convex arc surface, and the inner wall surface of the first receiving groove 51 can be concentric with the arc surface of the outer wall surface of the first middle shell 50, or it can be non-concentric.

In some examples, the outer wall surface of the first middle shell 50 is a convex arc surface, and the inner wall surface of the first middle shell 50 is a concave arc surface. The first middle shell 50 has an outer circular edge and an inner circular edge located at the first opening 52, and the outer circular edge and the inner circular edge coincide with the center of the first joint surface 22.

The convex arc surface of the outer wall surface of the first middle shell 50 and the concave arc surface of the inner wall surface of the first receiving groove 51 are arranged concentrically, and the geometric centers of the convex arc surface of the outer wall surface of the first middle shell 50, the concave arc surface of the inner wall surface of the first receiving groove 51, and the first opening 52 coincide with each other. In this example, the geometric center of the first opening 52 also coincides with the center of the first joint surface 22, so that the first middle shell 50 is a hollow hemispherical or nearly hemispherical structure, and the center of the hemispherical shape of the first middle shell 50 coincides with the center of the positive electrode sheet 20.

Since the first opening 52 can be used to allow the electrolyte to flow to the first joint surface 22, by setting the first middle shell 50 at the center of the positive electrode plate 20, the first middle shell 50 can be used to replenish the electrolyte to the first joint surface 22 while making the first middle shell 50 have less impact on the material of the positive electrode plate 20. When the positive electrode plate 20 is subjected to external force, unnecessary deformation of the positive electrode plate 20 material near the first middle shell 50 can be avoided.

Please refer to Figure 13. In some examples, the battery also includes a second middle shell 60 embedded in the negative electrode plate 30. The second middle shell 60 is provided with a second accommodating groove 61. The second accommodating groove 61 has a second opening 62 that passes through the second joint surface 32. The second middle shell 60 is also provided with a second guide hole 63 connected to the second accommodating groove 61.

The second middle shell 60 has a second receiving groove 61 inside, so that a hollow structure capable of receiving electrolyte is formed inside the second middle shell 60, and the second opening 62 is connected to the second receiving groove 61, so that the electrolyte in the second receiving groove 61 can flow outward. The second opening 62 penetrates the second joint surface 32, which means that the second receiving groove 61 is connected to the side of the second joint surface facing the isolation member 40 through the second opening 62.

The second flow guide holes 63 are through holes connecting the outside of the second middle shell 60 and the second containing groove 61, so that the electrolyte in the negative electrode plate 30 can enter the second containing groove 61 through the second flow guide holes 63. The second flow guide holes 63 can be straight holes or oblique holes evenly distributed on the second middle shell 60, or can be through holes of other shapes.

When the negative electrode sheet 30 is squeezed, the electrolyte in the negative electrode sheet 30 can enter the second containing groove 61 through the second guide hole 63, and a certain amount of electrolyte is stored in the second containing groove 61, so that the electrolyte can be replenished to the second joint surface 32 through the second opening 62. The electrolyte can also be replenished into the negative electrode sheet 30 again through other second guide holes 63 to improve the problem of uneven electrolyte caused by the negative electrode sheet 30 being squeezed. When injecting electrolyte into the battery, part of the electrolyte can enter the second containing groove 61 through the second guide hole 63, so that a certain amount of electrolyte can be stored in the second middle shell 60. When necessary, the electrolyte in the second containing groove 61 can be replenished to the position of the separator 40 through the second opening 62. By replenishing the electrolyte in the second containing groove 61 to the second joint surface 32, the lithium precipitation reaction at the second joint surface 32 can be avoided, which can help improve the safety of the battery.

In some examples, the second middle shell 60 and the first middle shell 50 are symmetrically arranged on both sides of the isolation member 40. In some examples, the second middle shell 60 and the first middle shell 50 are staggered on both sides of the isolation member 40. The staggered arrangement means that when projected on a plane parallel to the first joint surface 22, the projections of the first middle shell 50 and the second middle shell 60 are at least partially open. In some examples, the shape and size of the second middle shell 60 are consistent with those of the first middle shell 50.

The shape of the outer surface of the second middle shell 60 may be hemispherical or other shapes, and the shape of the inner surface of the second middle shell 60 may be consistent with or inconsistent with the shape of the outer surface.

In some examples, the negative electrode plate 30 is provided with the accommodation hole 23 described in the above example, and the second flow guide hole 63 of the second middle shell 60 may be connected to the accommodation hole 23 or may not be connected to the accommodation hole 23 .

In some examples, the number of the second middle shell 60 is multiple, and the multiple second middle shells 60 are distributed at intervals. By setting multiple second middle shells 60, multiple cavities for accommodating electrolyte can be formed at the position of the negative electrode plate 30 close to the separator 40 to replenish the electrolyte at the position of the second joint surface 32. Further, the multiple second middle shells 60 can be distributed in a ring shape with the center of the second joint surface 32 as the center. In some examples, a plurality of the above-mentioned first middle shells 50 are embedded in the positive electrode plate 20, and the multiple second middle shells 60 and the multiple first middle shells 50 are symmetrically arranged on both sides of the separator 40; or, the multiple second middle shells 60 and the multiple first middle shells 50 are mutually staggered on both sides of the separator 40. In some examples, the geometric center of the second opening 62 of the second middle shell 60 coincides with the center of the second joint surface 32.

In some examples, when projected in a plane parallel to the second joint surface 32, the first opening 52 overlaps the second opening 62. The first opening 52 and the second opening 62 are respectively used to supplement electrolyte on both sides of the separator 40 to avoid lithium deposition or electrolyte bridge failure in the battery, thereby helping to extend the life of the battery and reduce thermal runaway of the battery.

In some examples, the first middle shell 50 and the second middle shell 60 are symmetrically distributed on both sides of the separator 40. The positions of the first middle shell 50 and the second middle shell 60 correspond to each other, and the shapes of the first middle shell 50 and the second middle shell 60 are the same, so that the anti-deformation performance of the positive electrode sheet 20 and the negative electrode sheet 30 are the same or close, and at the same time, the electrolyte stored in the first accommodating groove 51 and the second accommodating groove 61 can be replenished to the corresponding electrode material to ensure the cycle performance of the battery cell.

In some examples, the outer wall surface of the second middle shell 60 is a convex arc surface. When the negative electrode plate 30 is acted upon by an external force, the force exerted on the negative electrode plate 30 is transmitted to the second middle shell 60, and the negative electrode plate 30 is also subjected to a reaction force from the second middle shell 60. By forming a convex arc surface, the reaction force exerted by the outer surface of the second middle shell 60 on the negative electrode plate 30 is relatively more uniform and dispersed, thereby avoiding unnecessary deformation of the portion of the negative electrode plate 30 where the second middle shell 60 is embedded.

In some examples, the inner wall surface of the second receiving groove 61 is a concave arc surface. When the electrolyte flows along the inner wall surface of the second receiving groove 61 in the second receiving groove 61, the flow direction of the electrolyte along the arc surface can be more dispersed, so that the electrolyte can flow to the second joint surface 32 in a dispersed manner, so that the electrolyte can more fully infiltrate the negative electrode plate 30. Further, in some examples, the outer wall surface of the second middle shell 60 is a convex arc surface, and the inner wall surface of the second receiving groove 61 can be concentric with the arc surface where the outer wall surface of the second middle shell 60 is located, or it can be non-concentric.

In some examples, the outer wall surface of the second middle shell 60 is a convex arc surface, and the inner wall surface of the second middle shell 60 is a concave arc surface. The second middle shell 60 has an outer circular edge and an inner circular edge located at the second opening 62, and the outer circular edge and the inner circular edge coincide with the center of the second joint surface 32.

The convex arc surface of the outer wall surface of the second middle shell 60 and the concave arc surface of the inner wall surface of the second receiving groove 61 are arranged concentrically, and the geometric centers of the convex arc surface of the outer wall surface of the second middle shell 60, the concave arc surface of the inner wall surface of the second receiving groove 61, and the second opening 62 coincide with each other. In this example, the geometric center of the second opening 62 also coincides with the center of the second joint surface 32, so that the second middle shell 60 is a hollow hemispherical or nearly hemispherical structure, and the center of the hemispherical shape of the second middle shell 60 coincides with the center of the negative electrode sheet 30.

Since the second opening 62 can be used for electrolyte to flow to the second joint surface 32, by setting the second middle shell 60 at the center of the negative electrode plate 30, the second middle shell 60 can be used to replenish the electrolyte to the second joint surface 32 while making the second middle shell 60 have less impact on the material of the negative electrode plate 30. When the negative electrode plate 30 is subjected to external force, unnecessary deformation of the negative electrode plate 30 material near the second middle shell 60 can be avoided.

Please refer to Figures 1 to 3, and in combination with Figure 14, in some examples, the shell 10 includes a first shell 11 and a second shell 12, the first shell 11 has a hemispherical outer surface, and the first shell 11 is recessed with a hemispherical first chamber 111 and a first opening 112 connected to the first chamber 111; one of the positive electrode sheet 20 and the negative electrode sheet 30 is disposed in the first chamber 111; the second shell 12 is recessed with a hemispherical second chamber 121 and a second opening 122 connected to the second chamber 121; the other of the positive electrode sheet 20 and the negative electrode sheet 30 is disposed in the second chamber 121; the first opening 112 is connected to the second opening 122 so that the first chamber 111 is connected to the second chamber 121 to form an installation cavity.

The first shell 11 has a hemispherical first chamber 111, which means that a hollow chamber is recessed inside the first shell 11, and the inner wall surface of the hollow chamber is a hemispherical surface. The first opening 112 is an open part of the first shell 11, which is used to place the pole piece into the first chamber 111. The first shell 11 also has a hemispherical outer surface. In some examples, the arc surface where the outer surface of the first shell 11 is located coincides with the center of the arc surface where the inner surface of the first shell 11 is located, so that when the first shell 11 is subjected to an external force, the force transmitted to the pole piece inside the first shell 11 is also relatively dispersed and uniform, thereby avoiding the problem of uneven dispersion of the electrolyte due to uneven force on the pole piece.

The second housing 12 has a hemispherical second chamber 121, which means that a hollow chamber is recessed inside the second housing 12, and the inner wall surface of the hollow chamber is a hemispherical surface. The second opening 122 is an open portion of the second housing 12, and is used to place the electrode sheet into the second chamber 121. For the convenience of description, the following is an example of installing the positive electrode sheet 20 in the first chamber 111 and the negative electrode sheet 30 in the second chamber 121.

By matching the first shell 11 and the second shell 12, the shell 10 can be combined to form a spherical installation cavity. During installation, the first shell 11 is used as the shell 10 of the positive electrode sheet 20, and the second shell 12 is used as the shell 10 of the negative electrode sheet 30. After being installed separately, they are assembled to form a battery cell.

In this example, the first housing 11 may be made of aluminum, and the second housing 12 may be made of stainless steel. Other materials may also be selected as needed.

In some examples, conductive adhesive layers are respectively provided in the first shell 11 and the second shell 12, and the conductor is formed by the conductive adhesive. Correspondingly, the first shell 11 is provided with a first conductive adhesive layer, and the second shell 12 is provided with a second conductive adhesive layer. When the positive electrode plate 20 is installed in the first shell 11 covered with the first conductive adhesive layer, the first shell 11 forms a positive electrode; when the negative electrode plate 30 is installed in the second shell 12 covered with the second conductive adhesive layer, the second shell 12 forms a negative electrode. The separator 40 is placed between the first shell 11 and the second shell 12, and the first opening 112 and the second opening 122 are connected to each other to form a spherical battery.

Please refer to FIG. 13 . In some examples, the second housing 12 has a hemispherical outer surface. The outer surface of the first housing 11 and the outer surface of the second housing 12 are spliced together to form a spherical surface.

The outer surface of the first shell 11 and the outer surface of the second shell 12 are spliced together to form a spherical surface, which means that after the first opening 112 and the second opening 122 are connected to each other, the outer surface of the first shell 11 and the outer surface of the second shell 12 are spliced together to form a spherical surface.

By adopting a hemispherical outer surface, the force distribution of the first shell 11 and the second shell 12 is relatively dispersed and uniform when subjected to external force, thereby avoiding the problem of excessive electrolyte being squeezed out due to local uneven force caused by squeezing the battery cell when the shell 10 is subjected to external force.

Furthermore, in some examples, the first middle shell 50 described in the above example is embedded in the positive electrode sheet 20, and the second middle shell 60 described in the above example is embedded in the negative electrode sheet 30. The first shell 11 cooperates with the second shell 12, so that the forces on the positive electrode sheet 20 and the negative electrode sheet 30 are relatively dispersed and uniform. At the same time, the first middle shell 50 and the second middle shell 60 cooperate with each other to store the squeezed electrolyte in the middle of the battery cell. When the positive or negative electrode cycle is needed, the electrolyte can be replenished in time to ensure the cycle performance of the battery.

In some examples, the first housing 11 and the second housing 12 are detachably connected. The first housing 11 and the second housing 12 can be connected to each other by means of a mutual clamping connection, or the first housing 11 and the second housing 12 can be connected and fixed to each other by means of a connector 13. By adopting a detachable connection, the positive electrode and the negative electrode of the battery can be processed and formed separately, and then the two can be assembled and spliced.

Furthermore, in some examples, the battery further includes a connector 13, and the first housing 11 is connected to the second housing 12 through the connector 13. The connector 13 can be connected to the first housing 11 and/or the second housing 12 by threaded connection, clamping or bonding, so as to achieve a detachable connection between the first housing 11 and the second housing 12. There can be multiple connectors 13, and the first housing 11 and the second housing 12 are connected and fixed to each other through multiple connectors 13. The number of connectors 13 can also be one. In some examples, the connector 13 is arranged inside the battery, and when the first opening 112 and the second opening 122 are docked with each other, the connector 13 is respectively connected and fixed to the first housing 11 and the second housing 12, thereby achieving mutual connection between the two.

In some examples, the connector 13 is connected to the outer wall surfaces of the first housing 11 and the second housing 12. When the first housing 11 and the second housing 12 are docked, the connector 13 connects the first housing 11 and the second housing 12 from the outside, and the connector 13 does not interfere with the battery cells in the housing 10, thereby avoiding uneven force and uneven electrolyte distribution caused by local interference on the battery cells.

Please refer to FIG. 1 and FIG. 14 . Further, in some examples, the connecting member 13 is ring-shaped; the connecting member 13 is disposed around the outer surface of the housing 10 .

The connecting member 13 can be threadedly connected to the first housing 11 and/or the second housing 12. For example, during installation, the first housing 11 and the connecting member 13 are fixed to each other, and an internal thread is provided on the inner wall surface of the connecting member 13, and an external thread is provided on one end of the second housing 12 close to the second opening 122, and the second housing 12 is screwed into the inner side of the connecting member 13 and fixed by the thread.

In some examples, the positive electrode sheet 20 is disposed in the first chamber 111, and the negative electrode sheet 30 is disposed in the second chamber 121; the battery further includes a first conductive adhesive layer (not shown in the figure), which is disposed between the first convex arc surface 21 and the inner wall surface of the first chamber 111. The first conductive adhesive layer is laid on the inner wall surface of the first chamber 111, and the end surface of the first conductive adhesive layer on one side away from the inner wall surface of the first chamber 111 is arranged in contact with the first convex arc surface 21; the first conductive adhesive layer is used to cooperate with the positive electrode sheet 20 to form the positive electrode of the battery cell.

In some examples, the battery further includes a second conductive adhesive layer (not shown in the figure), which is disposed between the second convex arc surface 31 and the inner wall surface of the second chamber 121. The second conductive adhesive layer is laid on the inner wall surface of the second chamber 121, and the end surface of the second conductive adhesive layer on one side away from the inner wall surface of the second chamber 121 is arranged in contact with the second convex arc surface 31. The second conductive adhesive layer is used to cooperate with the negative electrode plate 30 to form the negative electrode of the battery cell.

In some examples, the positive electrode sheet 20 is disposed in the first chamber 111, and the negative electrode sheet 30 is disposed in the second chamber 121; the battery further includes a first conductive adhesive layer and a second conductive adhesive layer, the first conductive adhesive layer is laid on the inner wall surface of the first chamber 111, and the end surface of the first conductive adhesive layer on one side away from the inner wall surface of the first chamber 111 is arranged in contact with the first convex arc surface 21; the second conductive adhesive layer is laid on the inner wall surface of the second chamber 121, and the end surface of the second conductive adhesive layer on one side away from the inner wall surface of the second chamber 121 is arranged in contact with the second convex arc surface 31. The first conductive adhesive layer is used to cooperate with the positive electrode sheet 20 to form the positive electrode of the battery cell; the second conductive adhesive layer is used to cooperate with the negative electrode sheet 30 to form the negative electrode of the battery cell, and the positive electrode and the negative electrode are combined to form the battery cell.

Based on the above battery examples, the present application also proposes an example of an electrical device, which includes a battery as described in any of the above examples.

It is worth noting that since the example of the electrical device in the present application is based on the example of the above-mentioned battery, the example of the electrical device in the present application includes all the technical solutions of all the above-mentioned battery examples, and the technical effects achieved are exactly the same, which will not be repeated here.

Please refer to Figures 1 to 14. In one example, the battery has a first hemispherical shell 11 and a second hemispherical shell 12. A first chamber 111 is formed inside the first shell 11, and a first conductive adhesive layer is laid on the inner wall surface of the first chamber 111. A positive electrode plate 20 having a first convex arc surface 21 is arranged in the first chamber 111, and the first convex arc surface 21 is attached to the first conductive adhesive layer to form the positive electrode of the battery cell. The positive electrode plate 20 has a first joint surface 22, and the first joint surface 22 is a circular plane. A second chamber 121 is formed inside the second shell 12, and a second conductive adhesive layer is laid on the inner wall surface of the second chamber 121. A negative electrode plate 30 having a second convex arc surface 31 is arranged in the second chamber 121, and the second convex arc surface 31 is attached to the second conductive adhesive layer to form the negative electrode of the battery cell. The negative electrode plate 30 has a second joint surface 32, and the second joint surface 32 is a circular plane. The battery is provided with a separator 40, which is arranged between the first joint surface 22 and the second joint surface 32. The first joint surface 22 and the second joint surface 32 are arranged opposite to each other, so that the positive electrode, the negative electrode and the separator 40 are combined to form a spherical battery cell. The overall shape of the battery is spherical. A connector 13 is provided on the outside of the shell 10, and the connector 13 is arranged around the connection between the first shell 11 and the second shell 12, so that the connector 13 fixes the first shell 11 and the second shell 12 to each other.

Since the battery is spherical as a whole, when an external force is applied, when the force is transmitted to the internal battery cell, the force acting on the battery cell can be dispersed to a certain extent, avoiding the concentration of force on the battery cell. Since both the positive electrode sheet 20 and the negative electrode sheet 30 are hemispherical structures, when the positive electrode and/or the negative electrode of the battery cell are subjected to force, the stress it is subjected to can be relatively uniform, thereby ensuring that the electrolyte saturation in each part of the positive electrode and the negative electrode is closer or the same, thereby making the power performance of the lithium ions in the positive electrode and the negative electrode consistent.

A receiving hole 23 is provided in the positive electrode plate 20 and/or the negative electrode plate 30 for receiving electrolyte, so that the electrolyte squeezed out by the force can be received in the receiving hole 23, and the electrolyte can replenish the parts with relatively less electrolyte in time, thereby making the electrolyte saturation of each part in the positive electrode and/or the negative electrode closer or the same, avoiding lithium precipitation caused by uneven distribution of the electrolyte.

In addition, a first middle shell 50 with a hollow structure is embedded in the positive electrode plate 20 and/or the negative electrode plate 30, and a second middle shell 60 with a hollow structure is embedded in the negative electrode plate 30; the hollow structure of the first middle shell 50 and the second middle shell 60 can timely store the electrolyte squeezed out of the electrode plate during the charging process in the middle of the battery cell, realize the electrolyte liquid seal for the electrode plate, and ensure that the electrode plate dynamics are not affected by the electrolyte.

By using the above-mentioned battery in an electrical device, thermal runaway of the battery of the electrical device can be prevented, and short circuit of the battery of the electrical device can be avoided, thereby effectively improving the power safety of the electrical device.

The above description is only an optional example of the present application, and does not limit the patent scope of the present application. All equivalent structural transformations made by using the contents of the present application specification and drawings under the inventive concept of the present application, or directly/indirectly applied in other related technical fields are included in the patent protection scope of the present application.

Claims (27)

1. A battery, comprising:

   A housing, wherein the housing is formed with a spherical mounting cavity;

   A positive electrode plate, disposed in the mounting cavity; the positive electrode plate has a first convex arc surface and a first bonding surface connected to the first convex arc surface;

   A negative electrode plate is disposed in the mounting cavity; the negative electrode plate has a second convex arc surface and a second bonding surface connected to the second convex arc surface; and

   The isolating member is arranged in the installation cavity and is located between the positive electrode sheet and the negative electrode sheet. The first joint surface and the second joint surface are arranged on both sides of the isolating member opposite to each other, so that the positive electrode sheet, the isolating member and the negative electrode sheet are spliced to form a spherical structure.
2. The battery according to claim 1, wherein the positive electrode sheet and/or the negative electrode sheet is provided with a plurality of receiving holes for receiving electrolyte.
3. The battery as claimed in claim 2, wherein a plurality of the receiving holes are distributed at intervals.
4. The battery according to claim 2 or 3, wherein a plurality of the accommodating holes are provided on the positive electrode sheet and the negative electrode sheet, and the accommodating holes on the positive electrode sheet are arranged corresponding to the accommodating holes on the negative electrode sheet.
5. The battery according to any one of claims 2 to 4, wherein the axial direction of the receiving hole is arranged perpendicular to the first joint surface.
6. The battery according to any one of claims 2 to 6, wherein the inner diameters of the plurality of accommodating holes are equal.
7. The battery according to claim 6, wherein the inner diameter of the receiving hole does not exceed 2 nm.
8. The battery according to any one of claims 2 to 6, wherein the plurality of accommodating holes include a first accommodating hole, a second accommodating hole, and a third accommodating hole, and the first accommodating hole, the second accommodating hole, and the third accommodating hole have different aperture sizes.
9. The battery according to claim 8, wherein the pore diameter of the first accommodating hole does not exceed 2 nm, and/or the pore diameter of the second accommodating hole does not exceed 10 nm, and/or the pore diameter of the third accommodating hole does not exceed 25 nm.
10. The battery according to any one of claims 1 to 9, wherein the battery further comprises:

    The first middle shell is embedded in the positive electrode plate, and is provided with a first receiving groove for receiving electrolyte, and the first receiving groove has a first opening extending through the first joint surface; the first middle shell is also provided with a first guide hole connected to the first receiving groove.
11. The battery according to claim 10, wherein the outer wall surface of the first middle shell is a convex arc surface.
12. The battery according to claim 10 or 11, wherein the inner wall surface of the first accommodating groove is a concave arc surface.
13. The battery according to claim 10, wherein the outer wall surface of the first middle shell is a convex arc surface, the inner wall surface of the first middle shell is a concave arc surface, the first middle shell has an outer annular edge and an inner annular edge located at the first opening, and the outer annular edge and the inner annular edge coincide with the center of the first joint surface.
14. The battery according to any one of claims 10 to 13, wherein the battery further comprises:

    The second middle shell is embedded in the negative electrode plate, and is provided with a second containing groove for containing electrolyte, and the second containing groove has a second opening that passes through to the second joint surface; the second middle shell is also provided with a second guide hole connected to the second containing groove.
15. The battery according to claim 14, wherein, when projected in a plane parallel to the second joint surface, the first opening overlaps with the second opening.
16. The battery according to claim 14 or 15, wherein the first middle shell and the second middle shell are symmetrically distributed on both sides of the diaphragm.
17. The battery according to any one of claims 14 to 16, wherein the outer wall surface of the second middle shell is a convex arc surface.
18. The battery according to any one of claims 14 to 17, wherein the inner wall surface of the second receiving groove is a concave arc surface.
19. The battery according to any one of claims 14 to 16, wherein the outer wall surface of the second middle shell is a convex arc surface, the inner wall surface of the second middle shell is a concave arc surface, and the second middle shell has an outer annular edge and an inner annular edge located at the second opening, and the outer annular edge and the inner annular edge coincide with the center of the second joint surface.
20. The battery according to any one of claims 1 to 19, wherein the housing comprises:

    A first shell, wherein the first shell has a hemispherical outer surface, and a hemispherical first cavity and a first opening communicating with the first cavity are concavely disposed in the first shell; one of the positive electrode sheet and the negative electrode sheet is disposed in the first cavity; and

    A second shell, wherein the second shell is provided with a hemispherical second chamber and a second opening connected to the second chamber; the other of the positive electrode sheet and the negative electrode sheet is arranged in the second chamber; the first opening is connected to the second opening so that the first chamber is connected to the second chamber to form the installation chamber.
21. The battery as claimed in claim 20, wherein the second shell has a hemispherical outer surface, and the outer surface of the first shell and the outer surface of the second shell are spliced to form a spherical surface.
22. The battery according to claim 20 or 21, wherein the first housing is detachably connected to the second housing.
23. The battery of claim 22, wherein the battery further comprises:

    A connecting piece, through which the first shell is connected to the second shell.
24. The battery according to claim 23, wherein the connecting member is connected to outer wall surfaces of the first outer shell and the second outer shell.
25. The battery as claimed in claim 24, wherein the connecting member is ring-shaped; and the connecting member is arranged around the outer surface of the shell.
26. The battery according to any one of claims 20 to 25, wherein the positive electrode sheet is disposed in the first chamber, and the negative electrode sheet is disposed in the second chamber; the battery further comprises:

    A first conductive adhesive layer is provided between the first convex arc surface and the inner wall surface of the first cavity;

    And/or, a second conductive adhesive layer is disposed between the second convex arc surface and the inner wall surface of the second cavity.
27. An electrical device, comprising the battery according to any one of claims 1 to 26.

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