Secondary battery having filling valve

The secondary battery includes a body part provided in a pillar shape on an outer wall and including a passage, through which the electrolyte flows, therein, a pin switch extending in a longitudinal direction of the body part, wherein, when a pressure is applied to an end of the pin switch, the pin switch linearly moves toward the inside, and when the pressure is removed, the pin switch linearly moves toward the outside, a manipulation part to move in a direction that is parallel to the pin switch, a pressure apply part protruding from a central portion of the manipulation part to apply a pressure an end of the pin switch, and a switching part disposed on the other end of the pin switch to open and close the passage.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of the priority of Korean Patent Application No. 10-2017-0075895, filed on Jun. 15, 2017, which is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a secondary battery, and more particularly, to a secondary battery which is capable of minimizing exposure of an internal structure and an electrolyte of the battery to air while re-injecting the electrolyte.

Description of the Related Art

Batteries (cells) that generate electric energy through physical or chemical reaction to supply the generated electric energy to the outside are used when AC power to be supplied to the building is not obtained, or DC power is required according to the living environments surrounded by various electronic devices.

Among such batteries, primary batteries and secondary batteries, which are chemical cells using chemical reaction, are generally used. The primary batteries are consumable cells which are collectively referred to as dry cells. On the other hand, a secondary battery is a rechargeable battery that is manufactured by using a material in which oxidation and reduction processes between current and a material are capable of being repeated many times. That is, when the reduction reaction to the material is performed by the current, power is charged. When the oxidation reaction to the material is performed by the current, power is discharged. Such charging-discharging are repeatedly performed to generate electricity.

Particularly, a lithium battery using lithium (Li) may be classified into a lithium metal battery, a lithium ion battery, and a lithium secondary battery according to types of electrolyte.

Here, since the lithium secondary battery has a solid or gel-type electrolyte, even if the battery is broken due to an unexpected accident, the electrolyte does not leak to the outside. Thus, since there is no possibility of ignition or explosion, stability may be secured, and energy efficiency may be improved.

Also, such a lithium secondary battery may not require a firm metal exterior and be manufactured in various sizes and shapes according to a use thereof. For example, the lithium secondary battery may have a thickness of 3 mm or less and a weight that is reduced by 30% or more. Thus, the lithium secondary battery may be mass-produced and manufactured in large size. For this reason, the lithium secondary battery has been commercialized at present and is being used in various fields.

In such a lithium secondary battery, crystal structures of a positive electrode and a negative electrode are collapsed due to a side reaction between a surface of the electrode and the electrolyte while the charging/discharging cycle is repeated, and the electrolyte is depleted to reduce the lifetime of the battery. Particularly, the lithium ions are deteriorated in mobility due to the depletion of the electrolyte to cause an increase in internal resistance, resulting in sudden deterioration in performance of the cell.

In recent years, various methods have been proposed which are capable of reducing the deterioration in performance of the secondary battery cell and also prolonging the service life by additionally injecting an electrolyte solution into the secondary battery cell. Representatively, there is a method of injecting the solution by using a syringe after opening an outer case of the cell through a physical method and then re-sealing the opened portion. However, in this method, the internal structure of the battery may be exposed to air to cause the oxidation of the electrode and the degeneration of the electrolyte. Thus, there has been a limitation that additional costs for preventing this phenomenon are required.

As another method, there is a method of sticking a needle of a syringe into a material such as rubber of a polymer material to re-inject the solution and then seal the stuck portion by itself. However, this method has a limitation that the number of times of re-injection is limited because the strength of the material is weakened by forming a hole at the portion that is stuck by the needle of the syringe once.

SUMMARY OF THE INVENTION

An aspect of the present invention provides a secondary battery which is capable of re-injecting an electrolyte into the secondary battery cell and minimizing exposure of an internal structure and the electrolyte of the battery to air.

The objects of the present invention are not limited to the aforementioned object, but other objects not described herein will be clearly understood by those skilled in the art from descriptions below.

According to another aspect of the present invention, there is provided a secondary battery includes: a body part provided in a pillar shape on an outer wall that surrounds an accommodation space in which an electrode assembly and an electrolyte are accommodated and including a passage, through which the electrolyte flows, therein; a pin switch extending in a longitudinal direction of the body part within the body part, wherein, when a pressure is applied to an end of the pin switch, the pin switch linearly moves toward the inside in which the accommodation space is defined, and when the pressure is removed, the pin switch linearly moves toward the outside; a manipulation part coupled to an outer circumferential surface of the body part to move in a direction that is parallel to the linear movement of the pin switch; a pressure apply part protruding from a central portion of the manipulation part to apply a pressure an end of the pin switch according to the movement of the manipulation part; and a switching part disposed on the other end of the pin switch to open the passage when the pin switch linearly moves toward the inside and close the passage when the pin switch linearly moves toward the outside.

The secondary battery may further include an elastic part having elasticity and providing a restoring force to the pin switch when the pressure is removed.

The elastic part may be lengthily disposed in a spiral shape according to a pillar of the pin switch.

The secondary battery may further include a cover part surrounding the pillar of the pin switch and the elastic part to extend in a direction of the pillar of the pin switch.

The cover part may have has corrosion resistance.

The secondary battery may further include a support coupled to an inner circumferential surface of the body part and including the passage therein.

The pin switch may pass through the support and is inserted into the support, and an end of the pin switch may protrude from the support to the outside.

The secondary battery may further include an elastic part having elasticity to provide a restoring force to the pin switch when the pressure is removed, wherein the elastic part may connect the support to the pin switch.

The secondary battery may further include first and second inflow and outflow holes through which the electrolyte is introduced into and discharged from the passage, the first and second inflow and outflow holes being respectively provided in an inner end and an outer end of the support.

The switching part may open or close the first inflow and outflow hole.

The support may be screw-coupled to the inner circumferential surface of the body part.

The manipulation part may include a third inflow and outflow hole through which the electrolyte is introduced into and discharged from the passage.

The body part may protrude outward.

The secondary battery may further include a case surrounding the outside of the outer wall.

The body part may be recessed into the outer wall of one side of the case.

Particularities of other embodiments are included in the detailed description and drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Unless terms used in the present invention are defined differently, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art. Also, unless defined clearly and apparently in the description, the terms as defined in a commonly used dictionary are not ideally or excessively construed as having formal meaning.

In the following description, the technical terms are used only for explaining a specific exemplary embodiment while not limiting the inventive concept. In this specification, the terms of a singular form may include plural forms unless specifically mentioned. The meaning of “comprises” and/or “comprising” does not exclude other components besides a mentioned component.

Hereinafter, preferred embodiments will be described in detail with reference to the accompanying drawings.

FIG. 1is a schematic view of a secondary battery1according to an embodiment of the present invention.

Referring toFIG. 1, the secondary battery1according to an embodiment of the present invention includes an accommodation space11in which an electrode assembly and an electrolyte are accommodated, an outer wall12surrounding the accommodation space11, and a valve20through which the electrolyte is injected into the accommodation space11.

The outer wall12surrounds the accommodation space11of the secondary battery1to prevent the electrode assembly and the electrolyte from being separated to the outside. If the secondary battery1is provided as a pouch type secondary battery, the outer wall12may be made of a soft material to be easily deformable by an external force. Alternatively, if the secondary battery1is provided as a prismatic or can type secondary battery, the outer wall12may be made of a hard material, and thus, a strong external force for deforming the shape of the outer wall12may be required.

The valve20is disposed on the outer wall12to connect the accommodation space11to the outside. Also, the electrolyte may be injected into the accommodation space11from the outside while preventing the electrolyte accommodated in the accommodation space11from leaking. The valve20will be described below in detail.

FIG. 2is a schematic view of the secondary battery1including a case13according to an embodiment of the prevent invention.

As illustrated inFIG. 2, the secondary battery1according to an embodiment of the present invention may further include the case13surrounding the outside of the outer wall12. In this case, the valve20may be formed to protrude to the outside of the case13, but it is preferable that the valve is formed to be recessed into one side of the case13. As the valve20does not protrude, an outer appearance of the secondary battery1may be elegant to provide a sense of beauty to the user. Furthermore, possibility of collision of the valve20from the outside may be reduced to prevent the valve20from being damaged. However, an embodiment of the present invention is not limited thereto. Although the case13is not provided, the valve may be formed in various methods, for example, the valve20may be formed to be recessed into the outer wall12.

FIG. 3is a view illustrating a structure of the valve20according to an embodiment of the present invention.

As illustrated inFIG. 3, the valve20according to an embodiment of the present invention adjusts a flow of the electrolyte. Also, the valve20includes a body part21disposed on the outer wall12of the secondary battery1, a support23coupled to an inner circumferential surface of the body part21, a pin switch24inserted to pass through the support23, and a manipulation part26applying a pressure to the pin switch24.

The body part21has a pillar shape241and is disposed on the outer wall12of the secondary battery1. However, the body part21may protrude from the outer wall12, but is not limited thereto. For example, the body part21may be recessed into the outer wall12. That is, the body part21may be variously formed as long as the body part21is capable of adjusting the flow of the electrolyte.

The support23is coupled to the inner circumferential surface of the body part21. Here, it is preferable that the support23is screw-coupled, but is not limited thereto. For example, the support23may be coupled in various manners such as bolt coupling, rivet coupling, and the like. A passage22through which the electrolyte flows may be provided in the support23. Also, inflow and outflow holes through the electrolyte is introduced into and discharged from the passage may be defined in both ends of the support23, respectively. According to an embodiment of the present invention, since the inflow and outflow holes are easily opened and closed by using the pin switch24, exposure of the electrolyte to air may be minimized. Although the passage22is provided in the support23, if the support23is not separately provided but is integrated with the body part21, the passage22may be provided in the body part21.

FIG. 4is a view illustrating a structure of the pin switch24according to an embodiment of the present invention.

As illustrated inFIG. 4, a pin switch24device according to an embodiment of the present invention includes a pillar241, a head242, and a switching part243.

The pillar241of the pin switch24lengthily extends in a longitudinal direction of the body part21. Also, the pillar241passes through the support23and is disposed in the passage22. The head242and the switching part243may be disposed on both the ends of the pillar241, respectively.

The head242is disposed on an outer end of the pin switch24. That is, the head242is disposed on an end, which is directed to the outside of the secondary battery1, of both the ends of the pin switch24. The head242protrudes from the pillar241in a radius direction of the outer circumferential surface. Thus, the head242does not pass through the support23through which the pillar241of the pin switch24passes. That is, the head242may prevent the entire pin switch24from being inserted into the support23, and thus, the elastic part25may allow the pin switch24to return to its original position. The manipulation part26may apply a pressure to the head242to allow the pin switch24to linearly move to the inside of the secondary battery1. The elastic part25and the manipulation part26will be described below in detail.

The switching part243is disposed on an inner end of the pin switch24. That is, the head242is disposed on an end, which is directed to the inside of the secondary battery1, of both the ends of the pin switch24. The switching part243also protrudes from the pillar241in the radius direction of the outer circumferential surface. Also, when the manipulation part applies a pressure to the head242, the switching part243opens the inflow and outflow holes of the passage22. When the pressure is removed, the switching part243closes the inflow and outflow holes of the passage22.

FIG. 5is a view illustrating a state in which the manipulation part26opens the valve20ofFIG. 3according to an embodiment of the present invention.

The manipulation part26applies a pressure to the pin switch24. As illustrated inFIGS. 3 and 5, the manipulation part26includes a body262screw-coupled to the outer circumferential surface of the body part21and a pressure apply part261protruding from a central portion toward the body part21.

The body262of the manipulation part26is coupled to cover the outer circumferential surface and an upper portion of the body part21. If the manipulation part26is not provided, the pin switch24may protrude to the outside of the support23and thus be exposed to the risk of collision. That is, the pin switch24may be easily impacted from the outside and may be easily broken by this impact, or the inflow and outflow holes may be opened. However, the manipulation part26may cover an upper portion of the body part26to prevent the pin switch24from being damaged or prevent the inflow and outflow holes from opened.

The pressure apply part261protrudes from the central portion of the manipulation part26toward the pin switch24. Also, when the user manipulates the manipulation part26to allow the manipulation part26to move, a pressure is applied to the head242disposed on an outer end of the pin switch24. Thus, the pin switch24may linearly move toward the inside of the secondary battery1.

The body262of the manipulation part26is screw-coupled to the outer circumferential surface of the body part21. Thus, the body part21may be disposed on the outer circumferential surface of the body part21to serve as a screw thread, and a screw may be disposed on an inner circumferential surface of the body to serve as a female screw. For example, when the manipulation part26rotates in a clockwise direction, since the body262and the body part21are fastened with respect to each other in a screw principle, the body262moves toward the inside of the secondary battery1. Thus, the pressure apply part261applies a pressure to the head242of the pin switch24to allow the pin switch24to linearly move toward the inside of the secondary battery1so that the switching part243opens the inflow and outflow holes. On the other hand, when the manipulation part26rotates in a counterclockwise direction, since the coupling between the body262and the body part21is released with respect to each other, the body262moves to be away from the secondary battery1. Thus, the pressure applied to the head of the pin switch24by the pressure apply part261may be gradually reduced so that the pin switch24returns to its original position to allow the switching part243to close the inflow and outflow holes.

The valve20of the secondary battery1according to an embodiment of the present invention further includes an elastic part25. The elastic part25connects the pin switch24to the support23or connects the pin switch24to the body part21. Also, when the pressure is removed, a restoring force is provided to allow the pin switch24, which has linearly moved, to return to its original position. The elastic part25may be made of a metal having elasticity such as a spring and may have a shape that lengthily extends in an axial direction while forming a circle having a predetermined size, for example, a spiral shape. However, the present invention is not limited thereto. For example, the elastic part25may have various sizes and shape as lone as the elastic part25generates the elastic force to provide the elastic force to the pin switch24.

The restoring force may be an actual elastic force generated from the elastic part25. That is, when the elastic part25is deformed while the pin switch24linearly moves, the elastic force is generated in proportion to the deformed degree and an elastic modulus. However, if the valve20of the secondary battery1does not include the elastic part25, the restoring force may be provided in a different manner so that the pin switch24returns to its original position. For example, a magnet may be attached to the support23and the pin switch24to generate a magnetic force and then generate electricity and thereby to generate an elastic force. That is, if the pin switch24returns to its original position when the pressure is removed, various methods may be used without limitation.

As illustrated inFIGS. 3 and 5, both sides of the passage22are opened so that first and second inflow and outflow holes232are provided on both sides of the support23. The electrolyte may be introduced and discharged through the first and second inflow and outflow holes232to flow along the passage22. The first inflow and outflow hole231is defined in an inner end of the support23. That is, the first and second hole231is defined in an end of both the ends of the support23, which faces the inside of the secondary battery1. The switching part243of the pin switch24opens and closes the first inflow and outflow hole231according to the pressure is applied thereto or removed therefrom. The first inflow and outflow holes231may have a diameter less than that of the switching part243. For this, the inner end of the support23extends while having a diameter that gradually decreases toward the inside of the secondary battery1. When the switching part243closes the first inflow and outflow hole231, the switching part243may come into close contact with the inner end of the support23. Thus, the passage22is closed to prevent the electrolyte from leaking through the first and second inflow and outflow hole231.

On the other hand, the second inflow and outflow holes232are defined in an outer end of the support23. That is, the first and second hole232is defined in an end of both the ends of the support23, which faces the outside of the secondary battery1. The second inflow and outflow hole232is always opened regardless of the movement of the pin switch24. Thus, the electrolyte may be introduced and discharged at any time through the second inflow and outflow hole232. However, as described above, when the first inflow and outflow hole231is closed, the electrolyte may not be injected into the accommodation space11defined in the secondary battery1even through the electrolyte flows along the passage22through the second inflow and outflow hole232.

FIG. 6is a plan view illustrating the manipulation part26according to an embodiment of the present invention.

As illustrated inFIG. 6, the manipulation part26includes a third inflow and outflow hole264in a top surface thereof. According to an embodiment of the present invention, even though the electrolyte in the secondary battery1is depleted, the electrolyte may be separately injected and supplemented by connecting an electrolyte injector. However, the manipulation part26may be disposed on the upper portion of the body part21to protect the pin switch24. It is preferable that the manipulation part is not separated from the body part21. Thus, the electrolyte injector may not be directly connected to the body part21but be connected to the manipulation part.

After the electrolyte injector is connected to the manipulation part, if the user manipulates the manipulation part26to open the first inflow and outflow hole231, the electrolyte is discharged from the electrolyte injector. Also, when the electrolyte is introduced into the valve20through the third inflow and outflow hole264of the manipulation part26, the electrolyte sequentially passes through the second inflow and outflow hole232and the first inflow and outflow hole231and then is injected into the accommodation space11. Thus, the electrolyte of the secondary battery1may be supplemented.

The manipulation part26further include a connection part263connecting the body262to the pressure apply part261. The pressure apply part261of the manipulation part26is disposed at a central portion of the manipulation part26. However, since the third inflow and outflow hole264is defined in the top surface of the manipulation part26, the connection part263connects the pressure apply part261to the body262. As a surface area of the top surface of the manipulation part26, which is occupied by the connection part263, decreases, the third inflow and outflow hole264may increase in surface area. Thus, the electrolyte may be more easily injected. However, as the injection pressure of the electrolyte increases, possibility of damage of the connection part263may increase. On the other hand, as the surface area of the top surface of the manipulation part26, which is occupied by the connection part263, increases, the possibility of damage of the connection part263may decrease. However, since the third inflow and outflow hole264decreases in surface area, it is difficult to inject the electrolyte. Thus, optimal surface areas of the connection part263and the third inflow and outflow hole264, in which the electrolyte is easily injected while the possibility of damage of the connection part263is reduced, may be experimentally obtained.

FIG. 6illustrates the configuration in which the body262and the pressure apply part261are connected to each other through the connection part. However, the present invention is not limited thereto. For example, the body262and the pressure apply part261may be integrated with each other without the separate connection part263. In this case, the third inflow and outflow hole264may be provided by separately performing a punching operation on the top surface of the manipulation part26or by intentionally obstructing the injection of casting.

FIG. 7is a view illustrating a structure of a valve20according to another embodiment of the present invention.

The valve20of a secondary battery1according to another embodiment of the present invention further includes a cover part27. Hereinafter, duplicated description with those of the secondary battery1according to the abovementioned embodiment of the present invention will be omitted. The omitted contents may be easily deducted from the contents of the secondary battery1according to the abovementioned embodiment of the present invention by the person skilled in the art. Thus, although a portion of the contents of the secondary battery1according to another embodiment of the present invention is omitted, the person skilled in the art may easily carry out the features.

As described, an elastic part25is spirally disposed around a pillar241of a pin switch24. As illustrated inFIG. 7, the cover part27covers an elastic part25and the pillar241of the pin switch24to lengthily extend in a longitudinal direction of the pillar241of the pin switch24.

The cover part27may be made of a corrosion resistant material, for example, a polymer. In general, the electrolyte accelerates oxidation and reduction reactions of a positive electrode and a negative electrode of the secondary battery1and thus is resistant to corrosion. However, according to an embodiment of the present invention, since the elastic part25is exposed within a passage22, when the electrolyte is injected, the elastic part25may come into contact with the electrolyte as it is. However, as described above, the elastic part25is made of a metal material having elasticity. Thus, the elastic part25may be easily corroded by the electrolyte having the strong corrosive property to reduce lifespan and increase costs and effects for replacement.

However, in the secondary battery1according to another embodiment of the present invention, the cover part27having the high corrosion resistance covers the elastic part25. Thus, the contact with the elastic part25may be prevented to increase the lifespan of the elastic part25.

FIG. 8is a view illustrating a state in which the manipulation part26opens the valve20ofFIG. 7according to another embodiment of the present invention.

The cover part27covers the elastic part25and extends from a head242of the pin switch24to a switching part243. Also, the cover part27seals the contact portion between the head242of the pin switch24and the switching part243. Thus, the electrolyte may not be introduced into the cover part27to prevent the electrolyte from coming into contact with the elastic part25. As illustrated inFIG. 8, even though the manipulation part26is manipulated, and thus, the pin switch linearly moves, the above-described feature is the same. Since the cover part27is disposed between the head242of the pin switch and the switching part243, when a pressure is applied to the pin switch24, and thus, the pin switch24moves, the head242and the switching part243may move together with the pin switch24. Thus, even though the pin switch24linearly moves, the sealed state of the cover part27and the contact portion between the head242and the switching part243may be maintained.

However, to connect the elastic part25to a support23, an end of the elastic part25may pass through the cover part27to protrude. In this case, the end of the elastic part25may come into contact with the electrolyte, and thus, the end of the elastic part25may be accelerated in corrosion. Thus, although not shown, the end of the elastic part25protruding bypassing through the cover part27may be covered by a separate member having high corrosion resistance. That is, according to another embodiment of the present invention, various methods may be used without limitation as long as the contact between the elastic part25and the electrolyte is prevented.

The embodiments of the present invention may have at least the following effects.

The electrolyte may be re-injected into the secondary battery cell by using a schrader valve without limitation in number, and also, the exposure of the internal structure and the electrolyte of the battery to the air may be minimized.

In addition, the manipulation part may be disposed on the upper portion of the valve to protect the pin switch of the schrader valve so that the pin switch is not subjected to a pressure even when a small impact is applied.

Also, the user may manipulate only the manipulation part to easily adjust the switching of the schrader valve.

The effects of the prevent invention are not limited by the aforementioned description, and thus, more varied effects are involved in this specification.

Those with ordinary skill in the technical field of the present invention pertains will be understood that the present invention can be carried out in other specific forms without changing the technical idea or essential features. Therefore, the above-disclosed embodiments are to be considered illustrative and not restrictive. Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing description and the exemplary embodiments described therein. Various modifications made within the meaning of an equivalent of the claims of the invention and within the claims are to be regarded to be in the scope of the present invention.