Art
[1]The present invention relates to a cap assembly comprising a guide member for preventing the detachment of the safety vent.
BACKGROUND
[2]As the technology developed, and the demand for mobile devices increases, demand on the energy source a secondary battery as there is increasing rapidly, and that the secondary number of studies have been done for one cell a high energy density as a lithium secondary battery, the discharge voltage is also commercially widely It is used.
[3]
This secondary battery according to the shape of the battery case, the electrode assembly is classified as a cylindrical battery and a prismatic battery that is embedded in a metallic can of cylindrical shape or square shape, the electrode assembly is a pouch-shaped battery that is embedded in a pouch-shaped case of the aluminum laminate sheet . That of the cylindrical battery has the advantage of being relatively large and structurally stable capacity.
[4]
An electrode assembly that is incorporated in the battery case is a cathode / separator / a multilayer structure of the negative electrode as a battery element capable of charging and discharging is made, the active material is wound via a separator between the positive electrode and the negative electrode of a long sheet-shaped coating jelly-roll-type and a given is classified as a stack / folding type in the unit cell, such as a plurality of anode and a cathode sequentially stacked on a separator is interposed in a stacked state, and a pull cell or bi-cell of a size that is wound by a separate film. Jelly of which - the rolled electrode assembly is manufactured easily and has a high energy density per unit weight advantages.
[5]
Figure 1 and the vertical cross-sectional view of the top assembly of a typical cylindrical cell is shown, and Fig. 2 shows a perspective view of a safety vent of Figure 1 is shown schematically.
[6]
1 and 2, top cap 10 is raised and the overhang, bottom, the PTC element which increases when the internal battery temperature rise cell resistance significantly by blocking current (positive temperature coefficient element: 20), a normal state, the downwardly protruding a shape and ruptured as projected upon a pressure rise in the battery safety vent 30, and the upper side portion is coupled to the safety vent 30 and the bottom of one side of the electrode assembly to the gas exhaust ( is connected to the positive electrode connecting plate 50 with 40) are positioned in sequence.
[7]
A safety vent (30) as a whole the center portion of the circular plane formed of a hollow structure, made of an inclined surface 33, which concave center, the flat portion 35, and flat outer circumferential surface of the part 35 increases the circumferential upwardly becomes, the upper inclined surface are formed in the outer peripheral surface 31 which is bent outward and parallel to the plane surface 34. The outer peripheral surface 31 and the inclined surface 33, the first bending portion 32 and the inclined surface 33 and the flat portion 35 of the second bending portion 34, due to internal pressure rise of the battery recess portion protruding between between easy the shape is deformed, and a notch is formed so as to be eliminated.
[8]
The second, most of the bending portion 34, but is a flat surface portion 35 and the inclined portion 33 is bonded weakly due to the notch structure, the second bending portion part 36 is a separate flat portion 35 of the inclined portion It is connected to the strong bonding by welding from being released from the 33.
[9]
In this way, by the flat part welded because it is engaged with the inclined portion, even if the internal pressure of the battery cell increases the advent of rupture to vent, the vent is not fully open, the space between the safety vent and the top cap or the PTC element is very narrow Therefore, it is difficult to secure a wider path which the gas is discharged.
[10]
Therefore, the situation to ensure wider than the path of the exhaust gas a high need for a technology that has the gas discharge in the battery cell can be made faster and faster.
Detailed Description of the Invention
SUMMARY
[11]
An object of the present invention is to solve the technical problem, which has been requested from the problems, and of the prior art.
[12]
The inventors of the present application are at the end of extensive research and various experiments in depth, as will be described later, when the safety vent constituting the cap assembly and the cylindrical can remove ruptured by the internal pressure rise of the battery, a rupture of the safety vent by attaching the guide member inside the cap plate to prevent the exit region, leading to the confirmation that the gas can be widely secured for the discharge path, and completed the present invention.
Problem solving means
[13]
Cap assembly according to the present invention for achieving this purpose, a cap assembly mounted on the open upper end of the can in a cell having a structure that an electrode assembly that is embedded in a cylindrical can, as rupture when the internal pressure rise of the battery is safe to the gas discharge vent, a current blocking member which is mounted on top of the safety vent, is attached upwardly convex cap plate of which is formed a through-hole for the gas outlet, on the bottom of the safety vent, and the interruption of current during the rising of the battery internal pressure in order to prevent and that rupture of the safety vent ruptures by the pressure rise of the departure cell may include a guide member that is attached to the inner side of the cap plate.
[14]
Thus, the present invention comprises a structure that is used to cap the assembly of the guide member attached to the inner side of the cap plate structure, and an inner bending of the safety vent when the internal pressure rise of the battery portion as completely fracture separation from the rest of the safety vent bar, because the discharging path of the gas that causes the battery internal pressure rise can be more widely ensured, can be safely and quickly made the discharge of gas.
[15]
Therefore, when the rupture of the safety vent to discharge the internal cell gas to the prior art, the safety vent bend portion is broken, but not part of bent part is not rupture event is by not fully opened, to discharge the internal cell gas to ensure the passage can solve difficult problems.
[16]
Further, since there is no need to perform a method such as welding to join so as not break the bend portion of the safety vent as in the prior art, since the manufacturing process of the battery further simplified, it is possible to obtain the effect of improving productivity.
[17]
When a cylindrical battery selneun increased cell bars cells that make the internal pressure rise of, the internal cell pressure above a certain level, as the gas inside the battery cells generated in the charge-discharge procedure, as part of the safety vent ruptures the gas It is discharged
[18]
Thus, the guide member has, can act to prevent a rise in the cap plate direction to prevent the parts of the safety vent is separated when the internal pressure of the battery rises is in conflict with the cap plate.
[19]
Including in one specific example, the safety vent, the outer part 1 bent to be downwardly bent from the periphery, wherein the downwardly extending inclined portion from the first bent part, and the parts of the horizontally bent second bent toward the center from the inclined portion and there may be a first bent portion and the second notch are formed in the structure in which the bent portion 2 from the bent portion, leading to rupture when the internal pressure of the battery rises.
[20]
That is, the safety vent of the first bent portion and the second by the bent portion may be formed of a structure in which a downward recess, said second notches are formed in the bent portion while Notch rupture when the cell internal pressure rising gas It may be made of a structure to be discharged to the outside.
[21]
The safety vent, while the shape is reversed when the battery internal pressure rises primarily the recessed portion is deformed so as to be convex toward the upper direction, the internal cell pressure when even higher, the in which the notch is breaking structure is formed on the portion 2 bend It can be formed.
[22]
Or, when the internal pressure rise of the battery, in the recess is not the shape of the safety vent reverse state may be a structure in which the notch is formed at the rupture portion second bent.
[23]
The current blocking member is a member which is ruptured when pressure rises in the battery cut off the current, in particular, there is an upwardly protruding projection which is attached by welding to the lower end of the safety vent is formed in the center, the discharge of the gas through two or more may be made of a structure for spheres are formed.
[24]
The current blocking member as a connection part between a current cut-off member and the positive electrode in accordance with the burst-like reversal of the safety vent due to internal pressure rise will interrupt the current. The projecting portion is may be a notch in the outer circumferential surface is formed as a notch portion is ruptured according to the shape inversion of the safety vent protrusion is easily be separated, combined with the safety vent state current blocking member and the connection part of the positive electrode of the electrode assembly and can.
[25]
The through-spheres may be formed in an arc shape in a radial symmetrical position around the center of the current blocking member. In this manner, when formed of a radially symmetric locations has the advantage of being able to prevent the exhaust gas excessively biased in one direction it is possible to ensure the strength of the current blocking member itself.
[26]
In one specific example, the second bending portion may have the whole of the bent portion 2 forms a closed curve when the internal pressure rise of the closed curve in the form of bars, which may be a battery notch shape can be easily ruptured. Thus, the central portion of the safety vent ruptures in a plane circle can be easily separated from the rest of the safety vent.
[27]
In the outer periphery of the lower projecting portion of the guide member is said to increase the rupture of the ruptured safety vent while preventing completely escape, which have the same member to secure the large gas discharge passage bar, the cap plate toward the center of the cap plate It may be an extending structure.
[28]
The guide member may be a structure that is formed in a width in the range of 0.3R to R relative to the radius (R) of the lower projecting portion of the cap plate, when the width of the guide members is smaller than 0.3R has been ruptured to increase safety If it is difficult to prevent separation of the vent is greater than R, the smaller becomes the angle of the inclined surface formed by the rupture of the safety vent is difficult to secure a gas exhaust passage
[29]
The guide member is to quickly discharge the gas in the battery, based on a plane circle to the bar, when the projection of the cap plate to be able to secure a large gas discharge passage as possible to the outer periphery, 10 to 90 degrees It can be made into a size having a central angle of the range.
[30]
If the guide member is sized having a planar circle smaller central angle than 10 degrees relative to that when protrusions of the cap plate to the outer periphery is, it may be difficult to prevent separation of the safety vent, which instantaneously rises rapidly to 90 degrees If greater is not preferable, because even if the safety vent by a completely separate blocked by the rising guide member can be a problem to secure the gas discharge passage widely.
[31]
The safety vent, when the internal pressure of the battery rises, the second bending portion may be a notch rupture as the inclined portion and the second bent structure in which a separation unit flat portions that are separated by.
[32]
The separated flat portion, As inclined so that the inclined surface formed by the floor, it is possible to form the gas exhaust passage.
[33]
In this way, the cap assembly according to the present invention, since the attaching the guide member to the lower cap plate, one side face of the separation plane is suppressed is raised by the guide members, without rising in a parallel state with the ground, It is at an angle to form an inclined surface relative to the ground.
[34]
For example, the lower portion of the inclined surface is located on the lower surface of the guide member, the rapid and safe gas, because the upper portion of the inclined surface may be formed in this bar can be located in the opposite direction, the side of the upper portion of the inclined surface of the gas discharge passage wider emissions can be achieved.
[35]
In some cases, the cap assembly may include the addition of a member, such as a PTC element (positive temperature coefficient element) to increase when an increase in the internal temperature of the battery resistance significantly by blocking current. The PTC element may be, for example, it is interposed between the top cap and the safety vent.
[36]
The cap assembly includes a current blocking member, can be made to the current cut-off laminate structure of the upper cap member is a gasket, a safety vent, PTC element, and at least one gas outlet is formed for, the gasket mounted additionally on the outer peripheral surface of the stacked structure It may be a structure.
[37]
The electrode assembly includes, for example, an anode, a cathode, and a membrane structure is wound jelly is interposed between the positive electrode and the negative electrode - may be a roll-type electrode assembly is not limited thereto.
[38]
The material of said cylindrical can is not particularly limited, and preferably can be made is formed of one of stainless steel, steel, aluminum or their alloys.
[39]
The present invention also provides a cylindrical battery that includes the cap assembly. The cylindrical battery may be a lithium secondary battery that provides a high energy density, discharge voltage, and the output reliability is not limited thereto.
Brief Description of the Drawings
[40]
1 is a vertical cross-sectional view of the top assembly of a typical cylindrical battery;
[41]
Figure 2 is a perspective view of a safety vent of Figure 1;
[42]
Figure 3 is a vertical cross-sectional view of the top assembly of the present invention according to one embodiment;
[43]
Figure 4 is a perspective view of a current blocking member of Figure 3;
[44]
5 is a perspective view of a safety vent of Figure 3;
[45]
6 is a side view of the safety vent of Figure 3;
[46]
7 is a schematic diagram showing a side case of the Figure 3 the safety vent ruptures; And
[47]
Figure 8 is a bottom view of the cap plate attached to the guide member of Fig.
Best Mode for Carrying Out the Invention
[48]
In the following description, explained with reference to the drawings according to an embodiment of the present invention, which are for a more easy understanding of the invention, the scope of the present invention is not intended to be limited by it.
[49]
Figure 3 and shows a vertical cross-sectional view of the top assembly of the present invention according to a preferred embodiment, Figure 4 shows a perspective view of a current blocking member of Fig.
[50]
3 and 4, the cap assembly 100 is mounted on top of the safety vent 120, the safety vent 120 to be burst to discharge a gas when internal pressure increases in the battery, obtain through for gases that is attached to the lower end of the upwardly convex cap plate 110, safety vent formed, the cell internal pressure current interruption to the interruption of current during the rising member 130, and the rupture of the rupture of the safety vent to release the original position It includes a guide member 140 for preventing the collision with the top cap.
[51]
Between the cap plate 120 and the safety vent 120, the PTC element 151, and is disposed, a cap plate 120, PTC element 151 and the gasket of the structure surrounding the outer periphery of the safety vent 120 (150 ) it is mounted additionally.
[52]
A current blocking member 130 is ruptured when pressure rises in the battery as a member to cut off the current, and a projection 132 upwardly protruding attached by welding at the bottom of the safety vent 120 is formed in the center, the protrusions 132 has a notch 135 to connect the three through-holes 137 and the through-holes 137 concentrically with the center is formed in the bridge is formed.
[53]
Further, the outer peripheral surface of the current blocking member 130 has three through spheres 136 for the discharge of gas are formed in an arc shape in a radial symmetrical position about the central axis.
[54]
The current blocking member 130 while the connections between the current blocking member 130 and the positive electrode to break rupture separation of the safety vent 120 due to the internal pressure rise is cut off the current. Projection 132 outer peripheral surface, and a notch 135 is formed, while the notch 135 parts ruptures along the tear separation of the safety vent 120 of the protrusion 132 is a positive electrode of the current blocking member 130 and the electrode assembly is the separation and connection.
[55]
Figure 5 and shows a perspective view of a safety vent of Figure 3, Figure 6 shows a side view of a safety vent of FIG.
[56]
5 and 6, the safety vent 120 includes a first bent portion 122, the first bent portion of the inclined portion 123 extends downward from the 122, the slope is downwardly bent from the outer periphery (121) a horizontal portion bent toward the center from a (123) is formed on the second bending portion 124 and the center is composed of a flat portion (125) parallel to the ground.
[57]
The second bending part 124 has a closed curve shape of the notch 129 is formed in the bar, while the notch is broken when the internal pressure of the battery increases the flat portion 125 is completely separate from the inclined portion.
[58]
7 shows a side view of the safety vent ruptures state of Fig.
[59]
7, the safety vent 120, but maintains a concave shape in a state the outer periphery 121 and the inclined portion 123 connected to the flat portion 125 is separated from the inclined portion 123, the cap plate It was moved in the direction.
[60]
A portion of the cap plate 110, the protrusions 111, when the outer periphery (112) has a flat, go to the bars and the cap plate direction is attached to the guide member 140 extends toward the center of the cap plate 125 of the and it is brought into contact, leading to form an inclined surface relative to the flat portion surface. That is, the lower inclined surface is positioned on the lower face of the guide member 140, the upper portion of the inclined surface is positioned on a guide member in the opposite direction. Thus, the inclined flat portion 125 and inclined portion 123, the space 101 in the so gas is a gas discharging path in all directions around the bar and the flat part that can be discharged can be formed quickly and reliably gas discharge between the this can be done.
[61]
8 shows a bottom view of the cap plate of FIG.
[62]
Referring to Figure 8, the lower surface of the cap plate 110 is made as close to 112, the outer two plane radius greater than the projection 111 of the cap plate 110, an outer periphery 111 is extended toward the center there is a guide member 140 is attached.
[63]
Guide member 140 is shown, but a fan-shape is a truncated apex portion, not limited to this shape, and may be formed of film with a large, in the form of linear or polygonal.
[64]
Width (W) of the guide member relative to the radius (R) of the lower cap plate projection made of a range of 0.3R to R, the circle of the outer peripheral plane relative to the (112) around the 360 ​​degree 10 to 90 degrees It may be formed of a central angle of 113 of the range.
[65]
Thus, since the cap assembly has a guide member attached to the lower cap plate according to the invention, while even if the separation is part of the safety vent ruptures increase is blocked by the guide member forms a slope to the bar, separating the safety vent all around the direction of gas emissions can be achieved quickly and safely.
[66]
Those of ordinary skill in the art that the present invention it will be possible to perform a variety of applications and modifications within the scope of the invention as disclosed in the accompanying claims.
Industrial Applicability
[67]
As described above, the cap assembly, in order to prevent separation of the safety vent to be ruptured to release the internal pressure rise when the gas of the cell, by attaching a member to guide the inner side of the cap playing, the safety vent according to the invention as the rupture completely eliminated from the rest of the safety vent at the same time capable of ensuring the passage of the exhaust gas wide, is leaving the rupture of the safety vent can be prevented from colliding with the cap plate.
[68]
Further, as the safety vent ruptures can omit the process for forming a fixing portion, such as welding in order to prevent completely eliminated, so there is an advantage that the manufacturing process of the battery cell simplified.

Claims

[Claim 1]The safety vent to the electrode assembly as the cap assembly mounted on the open upper end of the can in a cell having a structure that is embedded in a cylindrical can, as rupture when the internal pressure rise of the battery discharging the gas; It is mounted on top of the safety vent, a cap plate of the upward convex, which is formed with a through hole for the exhaust gas; A current blocking member which is attached to the lower end of the safety vent, a current interruption at the rise of battery internal pressure; And a guide member attached to the inner side of the cap plate to prevent the rupture of the safety vent ruptures by the pressure rise of the departure cell; And a cap assembly which is characterized in that comprises a.
[Claim 2]
The method of claim 1, wherein the guide member is a cap assembly which comprises a function to prevent the internal pressure of the safety vent portion is separated at the rise of the cell rising to the direction of the cap plate.
[Claim 3]
The method of claim 1 wherein the safety vent, comprising the outer part 1 bent to be downwardly bent from the periphery, wherein the downwardly extending inclined portion from the first bent part, and the parts of the horizontally bent second bent toward the center from the inclined portion and and; The first bent part and the cap assembly, characterized in that a notch portion of the second bent portion from the second bending, leading to rupture when the internal pressure rise of the battery is formed.
[Claim 4]
The method of claim 1, wherein the current blocking member, the upwardly protruding projection which is attached to the lower end of the safety vent is formed in the center, and characterized in that the two or more through-spheres for the discharge of gas are formed cap assembly.
[Claim 5]
The method of claim 4 wherein the spheres through the cap assembly being formed in an arc shape at a radially symmetrical positions around the center of the current blocking member.
[Claim 6]
The method of claim 3, wherein the cap assembly, characterized in that one bent portion is notched in the form of a closed curve shape.
[Claim 7]
The method of claim 1, wherein the guide member is a cap assembly which is characterized in that the structure extends toward the center from the outer periphery of the lower projecting portion of the cap plate.
[Claim 8]
The method of claim 1, wherein the guide member is a cap assembly being formed in a width in the range of 0.3R to R relative to the radius (R) of the lower projecting portion of the cap plate.
[Claim 9]
The method of claim 1, wherein the guide member has a cap assembly, characterized in that made in any size that has a central angle of the circle relative to the plane of the outer periphery when the protrusions of the cap plate, 10 to 90 degrees.
[Claim 10]
The method of claim 3, wherein the safety vent, when the internal pressure rise of the battery, while the second bent portion is notched fracture cap assembly characterized in that the flat portions separated by a separation that is based on the parts of the inclined portion and the second bending.
[Claim 11]
11. The method of claim 10, wherein the separated flat portion, As inclined so that the inclined surface formed by the floor, the cap assembly so as to form the gas exhaust passage.
[Claim 12]
The method of claim 11, wherein the cap assembly, characterized in that the lower portion of the inclined surface is located on the lower surface of the guide member, the upper portion of the inclined surface is located in the opposite direction.
[Claim 13]
The cylindrical battery cells, characterized in that it comprises a cap assembly according to any one of items 1 to 12.