Prismatic battery cell with one-way valve

Abstract

A prismatic battery cell has a battery case, an electrolyte, and a sealing member. The battery case has an internal cavity and a filling port. The filling port has an inner surface. The fill port is in fluid communication with the ambient environment and the interior cavity. The electrolyte is disposed in the internal cavity through a one-way valve in the sealing member. A sealing member is disposed in the filling port. The sealing member has an outer sealing surface forming a fluid seal with the inner surface of the fill port. The sealing member has a valve formed therein. The valve has an open position that allows the electrolyte to enter the interior cavity and a closed position that prevents the electrolyte from exiting the interior cavity. In addition, the valve allows degassing of the battery cells after the formation process.

Description

Technical Field

[0001] The present disclosure relates to a prismatic battery cell, and more particularly to a prismatic battery cell having an apparatus and method for filling the battery cell with an electrolyte during manufacturing. Background Art

[0002] Rechargeable energy storage systems (RESS), such as prismatic batteries, typically include multiple electrode stacks. Each electrode stack includes an anode and a cathode separated by an electrically insulating separator material. The electrode stacks are typically placed adjacent to each other in a housing or enclosure to protect the electrode stacks from the surrounding environment. The housing is also used to contain the electrolyte within the housing and around the electrode stacks. The electrolyte is deposited into the housing of the battery cell through the filling port. In the manufacturing process of the prismatic battery cell, an electrolyte filling tool (i.e., a funnel, a needle or a tube) is inserted into the filling port, the electrolyte is filled into the battery cell through the filling tool, the filling tool is pulled out of the filling port, and a temporary insert (i.e., a sealing plug) is positioned in the filling port to prevent the contents of the housing from escaping through the filling port. The formation process is initiated by applying an electric current to the electrodes for a specified duration, the temporary insert is removed from the fill port, the gas is released from the housing through the fill port, the fill tool is reinserted into the fill port, the cell is filled with electrolyte a second or more times as desired, the fill tool is removed from the fill port, a gasket insert or plug is applied to the fill port, and a closure plate is applied over the gasket insert and welded to the cell housing.

[0003] Although prior art methods and systems for manufacturing battery cells can achieve their specific purposes, there is still a need for new and improved battery cells and battery cell manufacturing processes. Thus, for example, a battery cell manufacturing process with fewer manufacturing steps is needed. Summary of the invention

[0004] According to several aspects of the present disclosure, a prismatic battery cell is provided. The prismatic battery cell includes a battery housing, an electrolyte, and a sealing member. The battery housing has an internal cavity and a filling port. The filling port has an inner surface. The filling port is in fluid communication with the surrounding environment and the internal cavity. The electrolyte is disposed in the internal cavity. The sealing member is disposed in the filling port. The sealing member has an outer sealing surface that forms a fluid seal with the inner surface of the filling port. The sealing member has a valve formed therein. The valve has an open position that allows the electrolyte to enter the internal cavity and a closed position that prevents the electrolyte from flowing out of the internal cavity.

[0005] According to another aspect of the present disclosure, the prismatic battery further includes a sealing plate disposed above the sealing member and covering the sealing member.

[0006] According to another aspect of the present disclosure, a sealing plate is secured to the battery housing to form a mechanical seal and a fluid seal between the battery housing and the interior cavity.

[0007] According to another aspect of the present disclosure, an inner surface of the filling port includes a first annular surface and a second annular surface.

[0008] According to another aspect of the present disclosure, an outer sealing surface of the sealing member has a first sealing annular surface that forms a first fluid seal with a first annular surface of the fill port.

[0009] According to another aspect of the present disclosure, the sealing member has a second sealing annular surface that forms a second fluid seal with a second annular surface of the fill port.

[0010] According to another aspect of the present disclosure, a first sealing annular surface of an outer sealing surface of the sealing member is formed on an annular edge of a first end of the sealing member.

[0011] According to another aspect of the present disclosure, a second sealing annular surface of the outer sealing surface of the sealing member is formed on a tapered portion of the sealing member at a second end of the sealing member.

[0012] According to another aspect of the present disclosure, the valve further comprises a tubular body having an inner annular edge at a first end. The inner annular edge forms an annulus. A fin is disposed at a second end of the tubular body. In a closed position of the valve, the fin seals against the tubular body to form a fluid-tight seal, and in an open position of the valve, the fin is disposed away from the tubular body so that it is in fluid communication with the internal cavity.

[0013] According to another aspect of the present disclosure, the sealing member is formed of at least one of a polymer and a polymer composite material, wherein the at least one of the polymer and the polymer composite material includes, for example, at least one of silicone and polyphenylene sulfide or similar materials.

[0014] According to another aspect of the present disclosure, the prismatic battery further includes a battery housing, an electrolyte, and a sealing member. The battery housing has an internal cavity and a filling port having an inner surface. The filling port is in communication with the surrounding environment and the internal cavity. The electrolyte is disposed in the internal cavity. The sealing member is disposed in the filling port and has an outer sealing surface and an inner tubular body. The outer sealing surface forms a fluid seal with the inner surface of the filling port. The internal tubular body has a one-way valve. The one-way valve includes a wing pivotably attached to the tubular body. The one-way valve has an open position that allows the electrolyte to enter the internal cavity and a closed position that prevents the electrolyte from flowing out of the internal cavity.

[0015] According to yet another aspect of the present disclosure, the prismatic battery cell further includes a sealing plate disposed above the sealing member and covering the sealing member.

[0016] According to yet another aspect of the present disclosure, a closure plate is secured to the battery housing to form a mechanical seal and a fluid seal between the battery housing and the interior cavity.

[0017] According to yet another aspect of the present disclosure, an inner surface of the filling port includes a first annular surface and a second annular surface.

[0018] According to yet another aspect of the present disclosure, an outer sealing surface of the sealing member has a first sealing annular surface that forms a first fluid seal with a first annular surface of the filling port.

[0019] According to yet another aspect of the present disclosure, the sealing member has a second sealing annular surface that forms a second fluid seal with a second annular surface of the fill port.

[0020] According to yet another aspect of the present disclosure, a first sealing annular surface of an outer sealing surface of the sealing member is formed on an annular edge of a first end of the sealing member.

[0021] According to yet another aspect of the present disclosure, a second sealing annular surface of the outer sealing surface of the sealing member is formed on a tapered portion of the sealing member at the second end of the sealing member.

[0022] According to another aspect of the present disclosure, a method for manufacturing a prismatic battery cell includes: filling an internal cavity of a battery case of a prismatic battery cell with electrolyte using a filling port provided on the battery case, inserting a sealing component having a one-way valve into the filling port of the battery case, starting a formation process of the battery cell, inserting a filling tube into the one-way valve of the sealing component, venting the internal cavity of the battery cell, filling the internal cavity of the battery case through the one-way valve of the sealing component, and removing the filling tube from the one-way valve of the sealing component.

[0023] According to yet another aspect of the present disclosure, the method further includes attaching a sealing plate over the sealing member and the fill port by welding the sealing plate to the battery housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

[0025] Figure 1A is a perspective view showing a prismatic battery cell according to the present disclosure;

[0026] Figure 1B is a diagram showing the method of passing through the Figure 1A an enlarged view of a partial cross-section of a fill port of a battery cell is shown;

[0027] Figure 2 Yes Figure 1B A cross-sectional view of a sealing member of a battery cell shown; and

[0028] Figure 3 is a flow chart of a method for manufacturing a prismatic battery cell according to the present disclosure. DETAILED DESCRIPTION

[0029] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.

[0030] Reference Figure 1A , shows a perspective view of a prismatic battery cell 10 according to the present disclosure. The battery cell 10 has a housing or casing 12, a top cover 14, terminals 16 and 18, a vent 20, and an electrolyte injection port or fill port 22. Figure 1A The housing or shell 12 is schematically shown and has a first side wall 24, a second side wall 26, a third side wall 28 (not shown), a fourth side wall 30 (not shown), and a bottom wall or floor 32 (not shown) that define an interior cavity 34. The interior cavity 34 is enclosed by the top cover 14. The present disclosure contemplates other housing configurations for the housing or shell 12 and is not limited to Figure 1A . In addition, the housing 12 is configured to contain or hold a suitable electrolyte. For example, the electrolyte is a liquid solution of an organic solvent and a lithium salt. In addition, the internal cavity 34 accommodates a plurality of electrode stacks (not shown), which are immersed in the electrolyte contained in the housing 12. The electrode stack includes a negative electrode or anode electrode, a separator, and a positive electrode or cathode electrode. The anode electrode is typically a thin metal plate that includes a protruding electrode sheet for providing an electrical connection between the anode electrode and the terminal 16 on the outside of the housing. Similarly, the cathode electrode is a thin metal plate that includes a protruding electrode sheet for providing an electrical connection between the cathode electrode and the terminal 18 on the outside of the housing. The electrode sheet is used as a current collector. The voltage generated between the anode electrode and the cathode electrode is transmitted to an external device (not shown) through the terminals on the housing 12. For example, the anode electrode and the electrode sheet are made of copper or other suitable materials, and are typically coated with graphite or graphite / silicon or other carbon-based materials or silicon oxide or lithium silicon. For example, the cathode electrode and electrode sheets are made of aluminum or other suitable materials and are typically coated with a lithium metal oxide, such as lithium cobalt oxide (LCO) or lithium nickel cobalt aluminum oxide (NCA) or lithium nickel cobalt manganese aluminum (NCMA) or lithium iron phosphate / lithium manganese iron phosphate (LFP / LFMP) or lithium rich manganese (LMR).

[0031] The different metals coated by the anode and cathode electrode materials (copper anode and aluminum cathode) of the prismatic battery 10 produce a galvanic reaction in the prismatic battery 10. For example, the graphite of the anode electrode and the LCO of the cathode electrode have different standard reduction potentials and are connected to an external circuit and separated from each other by a separator. The LCO with a lower potential will oxidize and release electrons, while the graphite with a higher potential will reduce and accept electrons. This process of releasing and accepting electrons will generate a current that can be used to power a device.

[0032] The diaphragm is typically a porous film or material layer that is located between the anode electrode and the cathode electrode and prevents the anode and cathode from contacting and causing a short circuit. The diaphragm allows lithium ions to pass through and close the circuit. Chemically stable porous composite materials, such as composite materials made of polyethylene (PE), polypropylene (PP) or other natural materials, can be used as diaphragms. In addition, inorganic nanoparticles such as TiO2, SiO2, Al2O3, AlO(OH) and ZrO2 can also be used to make coating composite materials for diaphragms. The diaphragm increases the internal resistance of the prismatic battery 10, which may reduce the power output and efficiency of the battery. The internal resistance depends on the thickness, porosity and composition of the diaphragm. Preferably, a thinner, more porous and more conductive diaphragm can reduce the resistance of the battery 10 and improve performance. The diaphragm is also selected to withstand high temperatures and manage thermal runaway, preventing the temperature from running away due to exothermic reactions. In addition, the diaphragm has a high melting point and low shrinkage to avoid contact between the anode and cathode electrodes. The separator has sufficient mechanical strength to resist puncture, tearing, or deformation during manufacture and operation of the battery cell 10. The separator also has dimensionally stable and flexible to conform to the shape of the electrode and accommodate volume changes during cycling. The separator is chemically inert and compatible with the electrolyte, electrodes, and other battery components. In addition, the separator has a low affinity for water or other impurities that could contaminate the electrolyte or cause corrosion of the electrodes.

[0033] Continue to refer Figure 1A , a vent 20 is provided in the top cover 14 at a suitable position on the surface of the top cover 14. Alternatively, the vent 20 can be located at the bottom of the shell 12. The vent 20 is in fluid communication with the internal cavity 34 of the shell 12. The vent 20 is formed of a gas permeable barrier, such as a material similar to that used to form the shell 12, however, the vent material is thinner than the shell 12. Releasing gas through the vent 20 can reduce excessive pressure in the shell 12 due to the generation of gas.

[0034] Fill port 22 provides a means for filling interior cavity 34 of housing 12 with electrolyte during the manufacturing process of battery cell 10. Fill port 22 includes aperture 36 (eg, Figure 1B The bore 36 is in fluid communication with the surrounding environment at a first end 38 and is in fluid communication with the interior cavity 34 of the housing 12 at a second end 40 .

[0035] Reference Figure 1B, shows an enlarged partial cross-sectional view of the fill port 22 through the housing 12 according to the present disclosure. During assembly of the battery cell 10 (described in more detail below), a one-way valve or sealing member component 44 is disposed in the hole 36 of the fill port 22. The sealing member 32 provides a means of filling the internal cavity 34 with electrolyte and allowing gas to escape the internal cavity 34 during the battery cell manufacturing process, which will be described in more detail below. In addition, in one aspect of the present disclosure, a fill port sealing plate 46 is provided to seal the fill port 22 after the manufacturing process is completed.

[0036] refer to Figure 2 , a cross-sectional view through a sealing member 44 is shown according to one aspect of the present disclosure. The sealing member 44 is disposed in the electrolyte fill port 22 to allow electrolyte to enter the interior cavity 34 and prevent electrolyte from flowing out of the interior cavity 34. The sealing member 44 has an outer sealing surface 50 for forming a fluid seal with the fill port 22. The outer sealing surface 50 includes a first annular edge 52 having a first sealing surface 54 and an annular conical portion 56 having a second sealing surface 58. The first sealing surface 54 is disposed at a first end 60 of the sealing member 44, and the second sealing surface 58 is disposed at a second end 62 of the sealing member 44.

[0037] The sealing member 44 is formed of a polymer or a polymer composite material. In one aspect of the present disclosure, the polymer or polymer composite material is silicone or polyphenylene sulfide, etc. The sealing member 44 plastically deforms at the sealing surfaces 54 , 58 to form a liquid-tight seal with the filling port 22 .

[0038] The filling port 22 has a first orifice portion 66 having a first diameter d1 and a second orifice portion 68 having a second diameter d2. The first diameter d1 of the first hole portion 66 is greater than the second diameter d2 of the second hole 68. The inner surface 70 of the filling port 22 is configured to form a fluid seal with the sealing member 44. In addition, the inner surface 70 of the filling port 22 includes a first inner surface 72 of the first hole 66 of the filling port 22 and a second inner surface 76 of the second hole 68. More specifically, the fluid seal is formed by the interference fit of the sealing member 44 within the filling port 22. The interference fit causes the first sealing surface 54 of the first annular edge 52 to deform and contact the first inner surface 72 of the first hole 66 and the second sealing surface 58 of the annular conical portion 56 to contact the second inner surface 76 of the second hole 68. In this way, a fluid seal is formed to prevent the electrolyte from escaping the internal cavity 34 of the battery cell 10.

[0039] The sealing member 44 is also used to allow the internal cavity to be filled with electrolyte when the sealing member 44 is disposed in the filling port 22. Therefore, the sealing member 44 includes an internal tubular body 80. The internal tubular body 80 has an annulus 82 located at a first end 84 of the internal tubular body 80 and a pivotable flap 86 located at a second end 88 to selectively close the internal tubular body 80, thereby forming a one-way valve. The annulus 82 has a central opening 90. The central opening 90 of the annulus 82 and the pivotable flap 86 can be in an open state "S ao ” and S fo ” to allow fluid (ie, electrolyte) to enter the internal cavity 34 of the battery cell 10; and in the closed state “S ac ” and S fc ” to allow fluid to flow out of the interior cavity 34. The central opening 90 and the pivotable flap 86 are biased in the closed position or state S ac and S fc , thereby forming a one-way fluid seal or one-way valve to prevent fluid from flowing out of the internal cavity 34.

[0040] The central opening 90 of the cuff 82 and the pivotable flap 86 are held in an open position by the force applied by the introduction catheter or needle or funnel 92. ao and S fo More specifically, the funnel 92 is placed in the annulus 82 and pushed inwardly into the inner tubular body 80 of the sealing member 44 and against the pivotable flap 86. The introduction of the funnel 92 causes the annulus 82 to plastically deform, thereby allowing the funnel to pass through the annulus 82. As the funnel 92 is further advanced into the inner tubular body 80 and against the pivotable flap 86, the pivotable flap 86 plastically deforms at the hinge portion 94, thereby allowing the flap 86 to open and rotate away from the end 88 of the inner tubular body 80 and allow fluid to enter the interior cavity 34. When the funnel 92 is removed, the annulus 82 closes and returns to its original shape or state S ac , and the flap 86 returns (rotates toward the open end 88) to its original position closing the end 88 of the inner tubular body 80 and returns to the closed position or state S fc .

[0041] Reference Figure 3, a flow chart of a method 100 for manufacturing a battery cell 10 according to the present disclosure is shown. The method 100 begins at frame 102, where a dry or empty prismatic battery cell housing is positioned for electrolyte filling. At frame 104, the electrolyte is deposited into the internal cavity of the battery cell through the filling port 22. At frame 106, the sealing member 44 is pressed into the filling port 22 to form a fluid seal, as described above. At frame 108, the formation process is started. During formation, at a specified temperature, current is applied to and removed from the electrodes of the battery cell 10 to charge and discharge the battery cell for the first time, thereby adjusting the internal structure of the battery cell. A solid electrolyte interface is formed on the anode electrode. The solid electrolyte interface is important for the stability and life of the battery cell. In addition, gas is generated during the formation process and must be released from the internal cavity 34 of the battery cell 10. At block 110, the funnel 92 is inserted into the inner tubular body 80 of the sealing member 44 to force the annulus 82 of the sealing member 44 into the open state S. ao , and push the flap 86 into the open state S fo At box 112, the gases generated during the formation process are degassed or removed, where the gases are released through the funnel 92. At box 114, the electrolyte is again deposited into the interior cavity 34 of the battery cell 10 through the funnel 92. At box 116, once the electrolyte substantially fills the interior cavity 34, the funnel 92 is removed, causing the annulus 82 and the tabs 86 to return to the closed position or state S. ac and S fc At block 118 , the closure plate 46 is applied over the sealing member 44 and covers the fill port 22 . At block 120 , the closure plate 46 is welded to the battery cell housing 12 .

[0042] The present disclosure has many advantages and benefits over existing systems and methods for manufacturing prismatic battery cells. For example, in some aspects of the present disclosure, the process for manufacturing prismatic battery cells is simplified. More specifically, the sealing member 44 of the present disclosure reduces the number of steps necessary to fill the battery cell with electrolyte, degas the battery cell, and then refill the battery cell with electrolyte. Therefore, the total time required to manufacture the battery cell is shortened.

[0043] This description is merely exemplary in nature and is not intended to limit the present disclosure, application, or use. The broad teachings of the present disclosure can be implemented in many forms. Therefore, although the present disclosure includes specific examples, the true scope of the present disclosure should not be so limited, because other modifications will become apparent after studying the drawings, the specification, and the appended claims.

Claims

1. A prismatic battery comprising: a battery housing having an interior cavity and a fill port having an interior surface, wherein the fill port is in fluid communication with an ambient environment and the interior cavity; an electrolyte disposed in the interior cavity; a sealing member disposed in the fill port, wherein the sealing member has an outer sealing surface that forms a fluid seal with an inner surface of the fill port, and wherein the sealing member has a valve formed in the sealing member; and wherein the valve has an open position allowing the electrolyte to enter the interior cavity and a closed position preventing the electrolyte from leaving the interior cavity. 2 . The prismatic battery according to claim 1 , further comprising a sealing plate disposed above the sealing member and covering the sealing member.

3. The prismatic battery of claim 2, wherein the sealing plate is secured to the battery housing to form a mechanical seal and a fluid seal between the battery housing and the interior cavity. 4 . The prismatic battery of claim 1 , wherein an inner surface of the filling port comprises a first annular surface and a second annular surface. 5 . The prismatic battery of claim 4 , wherein the outer sealing surface of the sealing member has a first sealing annular surface that forms a first fluid seal with a first annular surface of the fill port. 6 . The prismatic battery of claim 5 , wherein the sealing member has a second sealing annular surface that forms a second fluid seal with a second annular surface of the fill port. 7 . The prismatic battery of claim 5 , wherein the first sealing annular surface of the outer sealing surface of the sealing member is formed on an annular edge of the first end of the sealing member.

8. The prismatic battery according to claim 7, wherein: The second sealing annular surface of the outer sealing surface of the sealing member is formed on a tapered portion of the sealing member at a second end of the sealing member.

9. The prismatic battery of claim 1 , wherein the valve further comprises a tubular body having an inner annular edge at a first end, wherein the inner annular edge forms an annulus, a fin disposed at a second end of the tubular body, and wherein in a closed position of the valve, the fin seals against the tubular body to form a fluid seal, and in an open position of the valve, the fin is disposed away from the tubular body so that it is in fluid communication with the internal cavity. 10 . The prismatic battery of claim 1 , wherein the sealing member is formed of at least one of a polymer and a polymer composite.

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