Cap for Electrochemical Cell

Abstract

A cap assembly is disclosed that creates a hermetic seal with a cell can housing. The cap assembly includes an outer surface, an inner surface, and an outer periphery. The cap assembly further includes an electrolyte inlet port that forms a port opening between the outer surface and the inner surface, and a vent hole that is constructed to form a vent opening from the inner surface to the outer surface when a vent pressure differential is achieved between the outer surface pressure and the inner surface pressure. The vent hole is located (a) concentrically with the electrolyte inlet port, and (b) closer to the outer periphery than the location of the electrolyte inlet port.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application is also related to the following applications that have been filed, and the entire content of each of these applications is incorporated herein by reference: PCT / US20 / 048660 filed on August 30, 2020, PCT / US20 / 020547 filed on February 29, 2020, PCT / US20 / 048661 filed on August 30, 2020, PCT / US19 / 032413 filed on May 15, 2019, PCT / US19 / 032414 filed on May 15, 2019, PCT / US14 / 066015 filed on November 17, 2014, PCT / US20 / 026086 filed on April 1, 2020, PCT / US17 / 029821 filed on April 27, 2017, PCT / US22 / 031594 filed on May 31, 2022, U.S. Provisional Patent Application No. 63 / 328480 filed on July 7, 2022, U.S. Provisional Patent Application No. 63 / 391224 filed on July 21, 2022, U.S. Provisional Patent Application No. 63 / 391220 filed on July 21, 2022, U.S. Provisional Patent Application No. 63 / 418703 filed on October 24, 2022, and U.S. Provisional Patent Application No. 63 / 418704 filed on October 24, 2022.

[0002] This application claims the priority of U.S. Provisional Patent Application No. 63 / 306393 filed on February 3, 2022, and its entire content is incorporated by reference.

[0003] Embodiments of the present invention relate to electrochemical cells such as batteries and capacitors, the mechanical design of electrochemical cells, and a method for injecting electrolyte for manufacturing.

Background Art

[0004] Electrochemical energy storage devices such as batteries and double-layer capacitors are generally sold in four types of shape factors: prismatic, pouch, button, and cylindrical cells. These devices or cells have external metal electrical contacts on both the positive and negative electrodes for carrying current through a circuit. The cell housing often also features a vent hole, a burst disk, a rupture disc, or another mechanism for relieving internal pressure generated within the cell. The cell housing can also feature an injection port for injecting an electrolyte into the interior of the cell that houses the positive electrode, negative electrode, and separator.

[0005] Since such a mechanism is unnecessary, the cylindrical cell does not have an injection port in the cap assembly. In practice, first, as a first step, the electrolyte is injected into the cell, and subsequently, as a second step, the cap assembly is attached to the cell.

[0006] However, particularly in the case of a liquefied gas electrolyte, it is advantageous to fix the cap assembly to the cell housing as a first step and then inject the electrolyte into the cell as a second step. To prevent immediate evaporation of the liquefied gas electrolyte, it is necessary to fix the cap in a predetermined position as a first step, then inject the electrolyte as a second step, and as a third step, immediately seal the cell without releasing the pressure of the electrolyte to prevent evaporation of the electrolyte.

[0007] What is needed is a cell design that simplifies the process in a cost - effective manner. In this specification, a cap assembly is presented that includes an electrolyte injection port, a vent hole, and a metal electrical contact surface. The cap assembly can be attached to the cell can before electrolyte gas injection, simplifying the manufacturing process. Further, these mechanisms (i.e., the electrolyte injection port, the vent hole, and the metal electrical contact surface) may, moreover, have their geometric centers and geometric diameters measured and can have a relatively circular geometric shape as referred to throughout this invention. A further advantage from the perspective of the mass and volume of the cap assembly is to concentrically align all the centers of these three cap assembly mechanisms, minimizing the footprint of the cap while maintaining high performance and functionality of the device. This concentric configuration also minimizes the volume, mass, and cost of the cap assembly.

Summary of the Invention

[0008] This specification discloses a cap assembly that creates a hermetically sealed state together with a cell can housing. The cap assembly includes an outer surface, an inner surface, and an outer peripheral edge. The cap assembly further includes an electrolyte injection port that forms a port opening between the outer surface and the inner surface, and a vent hole that is constructed to form a vent hole opening from the inner surface to the outer surface when a vent pressure differential is achieved between the outer surface pressure and the inner surface pressure. The vent hole is arranged (a) concentrically with the electrolyte injection port and (b) closer to the outer peripheral edge than the position of the electrolyte injection port.

[0009] The outer peripheral edge may be circular or substantially circular. The vent hole can substantially surround the electrolyte injection port and can further include a double vent hole notch.

[0010] The cell can body can incorporate two electrodes, and the cap assembly can include an electrical contact surface constructed to enable electrical transmission from the outer surface to one of the electrodes. The electrical contact surface can be arranged (a) concentrically with the electrolyte injection port and (b) closer to the outer peripheral edge than the position of the electrolyte injection port. The electrical contact surface can substantially surround the electrolyte injection port. The electrical insulator can electrically insulate the electrical contact surface from the outer peripheral edge.

[0011] The cap assembly can include a welded joint adapted to connect the cell can body to the outer peripheral edge. The outer peripheral edge can include a shoulder adapted to contact the cell can body along two mutually perpendicular surfaces.

[0012] The injection port can be sealed by a screw plug, an expansion plug, a metal plug, or a welded plug. The injection port can also include a metal tube extending in a direction away from the outer surface that can be used to fill the cell can body with the electrolyte.

[0013] The outer peripheral edge can be part of the cap lid. The ring can press against the cap lid to compress a rubber gasket. The ring can be a shrink-fit ring or a crimping ring, and the rubber gasket can achieve electrical insulation.

[0014] The electrolyte injection port can include a valve that enables filling of the cell can body with the electrolyte.

[0015] One non-limiting example is an electrolyte injection port comprising a poppet, a compression spring connected to the poppet, and a valve seat. The electrolyte injection port has two types of configurations: an open configuration characterized in that the poppet compresses the spring and removes the poppet from the valve seat to form a port opening between the outer surface and the inner surface; and a sealed configuration characterized in that the spring is decompressed relative to the open configuration, the poppet is fitted to the valve seat, and a hermetically sealed state is formed to seal the closed port opening. The open configuration can be actuated by a force applied to the poppet. The poppet can also include a wedge stopper that limits the movement of the poppet.

[0016] A second non-limiting example is an electrolyte injection port comprising a ball, a compression spring connected to the ball, and a valve seat. The electrolyte injection port has two types of configurations: an open configuration characterized in that the ball compresses the spring and removes the ball from the valve seat to form a port opening between the outer surface and the inner surface; and a sealed configuration characterized in that the compression spring is decompressed relative to the open configuration, the ball is fitted to the valve seat, and a hermetically sealed state is formed to seal the closed port opening. The open configuration can be actuated by the injection pressure applied to the ball from the outer surface, and the injection pressure is at least greater than the cell can pressure applied to the ball from the inner surface. A retainer can be used to limit the movement of the ball.

[0017] A third non-limiting example is an electrolyte injection port comprising a conical plug and a rubber valve seat. The electrolyte injection port has two types of configurations: an open configuration characterized in that the conical plug is removed from the rubber valve seat to form a port opening between the outer surface and the inner surface; and a sealed configuration characterized in that the conical plug is fitted to the rubber valve seat to form a hermetically sealed state to seal the closed port opening. The open configuration can be actuated by the injection pressure applied to the conical plug from the outer surface, and the injection pressure is at least greater than the cell can pressure applied to the conical plug from the inner surface.

[0018] A fourth non-limiting example is an electrolyte injection port having a rubber stopper, a spring tab that contacts the rubber stopper, and a valve seat. The electrolyte injection port has an open configuration characterized in that the rubber stopper spreads the spring tab and removes the rubber stopper from the valve seat to form a port opening between the outer surface and the inner surface, and a sealing configuration characterized in that the rubber stopper fits with the valve seat to form a hermetically sealed state that seals the closed port opening. The open configuration can be actuated by the injection pressure applied to the rubber stopper from the outer surface, and the injection pressure is at least greater than the cell can pressure applied to the rubber stopper from the inner surface.

[0019] The injection port can be used to inject pressurized electrolyte (or solvent) into the cell can housing in each of the aforementioned non-limiting examples, and the port will automatically seal when the injection process is complete to prevent the pressurized electrolyte (or solvent) from leaking.

[0020] Further aspects, alternative forms, and variations that will be apparent to those skilled in the art are also disclosed herein and are considered to be specifically included as part of the present invention. The present invention is described only in the claims allowed by the Patent Office in this application or related applications, and the following summary description of specific examples does not limit, define, or otherwise determine the scope of legal protection in any form.

Brief Description of the Drawings

[0021]

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Mode for Carrying Out the Invention

[0022] In this specification, reference is made to several specific examples of the present invention, including every best mode contemplated by the inventors for carrying out the present invention. Examples of these specific embodiments are shown in the accompanying drawings. The present invention is described in conjunction with these specific embodiments, but it will be understood that the present invention is not intended to be limited to the embodiments described or illustrated. On the contrary, it is intended to cover alternative forms, modifications, and equivalents that may be included within the spirit and scope of the present invention as defined by the appended claims.

[0023] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. Certain exemplary embodiments of the present invention can be practiced without some or all of these specific details. In other instances, well-known operations of processes are not described in detail in order not to unnecessarily obscure the present invention. Various techniques and mechanisms of the present invention may be described in the singular for clarity. However, unless otherwise stated, some embodiments may include multiple repetitions of a technique or multiple mechanisms. Similarly, the various steps of the methods shown and described herein are not necessarily performed in the order shown in a particular embodiment, or at all. Thus, some examples of the methods discussed herein may include more or fewer steps than those shown or described. Further, the techniques and mechanisms of the present invention may describe a connection, relationship, or transmission between two or more entities. It should be noted that a connection or relationship between entities does not necessarily mean a direct and unobstructed connection, as various other entities or processes may exist or occur between the two entities. Thus, unless otherwise stated, the connections shown do not necessarily mean direct and unobstructed connections.

[0024] The following list of exemplary mechanisms corresponds to the accompanying figures and is presented for ease of reference. Like reference numerals indicate corresponding mechanisms throughout the specification and figures. 1 cell can housing 1-5 cap assembly 2 cap lid 2-1 outer surface 2-2 inner surface 2-3 outer peripheral edge 3 rubber gasket 4 electrical insulator 5 metal electrical contact surface 6 electrolyte injection port 6-1 port opening 7 poppet 7-1 portion extending from outer surface 7-2 force on poppet 7-3 poppet valve seat 7-4 force of compression spring 7-5 cell can (internal gas) pressure 8 wedge stopper 9 compression spring 10 metal tube 11 rubber ball 11-1 ball valve seat 11-2 injection pressure 11-3 cell can (internal gas) pressure 11-4 force of compression spring 12 compression spring 13 retainer 14 welding plug 15 conical plug 15-1 injection pressure 15-2 cell can pressure 16 rubber O-ring valve seat 18 set screw 19 rubber plug 20 spring tab 21 rubber plug 21-1 rubber plug valve seat 21-2 injection pressure 21-3 cell can (internal gas) pressure 21-4 force of spring tab 22 expansion plug 23 Weld joint 24 Single vent notch 24-1 Vent opening 25 Metal plug 26 Double vent notch 27 Washer 28 Burn-in or crimping ring 29 Shoulder 29-1 Surface of the first shoulder 29-2 Surface of the second shoulder

[0025] Current state-of-the-art cylindrical cells generally do not have an injection port in the cap assembly because the injection of the electrolyte into the cell is generally completed as a first step and then followed by the attachment of the cap assembly to the cell as a second step. In particular, in the case of a liquefied gas electrolyte, it is beneficial to first fix the cap assembly to the cell housing and then inject the electrolyte into the cell as a second step. In order to prevent the immediate evaporation of the liquefied gas electrolyte, it is necessary to fix the cap in a predetermined position as a first step, then inject the electrolyte as a second step, and then immediately seal the cell without releasing the pressure of the electrolyte as a third step to prevent the evaporation of the electrolyte.

[0026] In terms of manufacturing and cost, it would be even more beneficial to have all of the electrolyte injection port, vent hole, and metal electrical contact surface on the same cap assembly. These mechanisms may also have their geometric center and geometric diameter measured and can have a relatively circular geometric shape as referred to throughout this invention. A further benefit from the perspective of the mass and volume of the cap assembly is to concentrically align the centers of all three cap assembly mechanisms (electrolyte injection port, vent hole, and metal electrical contact surface) to minimize the footprint of the cap while maintaining high performance and functionality of the device. This type of concentric configuration not only minimizes the volume, mass, and cost of the cap assembly, but also simplifies manufacturing.

[0027] Referring to FIGS. 1 to 3, a novel cap assembly 1-5 that creates a hermetically sealed state together with the cell can 1 is shown. The cap assembly 1-5 includes an outer surface 2-1, an inner surface 2-2, and an outer peripheral edge 2-3. The electrolyte or solvent can be introduced into the electrochemical energy storage device through the electrolyte injection port 6. The electrolyte injection port 6 forms a port opening 6-1 between the outer surface 2-1 and the inner surface 2-2. The cap assembly 1-5 also includes a vent hole 24 constructed to form a vent hole opening 24-1 from the inner surface 2-2 to the outer surface 2-1 when the vent pressure difference between the outer surface pressure and the inner surface pressure is achieved or exceeded. The vent hole 24 is a weak part of the lid 2 and can be designed to open at a high cell internal pressure. This weak part of the lid 2 can be a thinner part of the lid 2 formed by a notch in the lid 2, thus providing a weak location where the cell can vent under high cell internal pressure. The vent hole 24 is arranged (a) concentrically with the electrolyte injection port 6 and (b) closer to the outer peripheral edge 2-3 than the position of the electrolyte injection port 6.

[0028] The cap assembly 1-5 can be connected to the cell can 1 via a welded joint 23. The cell can 1 may also have a circular geometry and may be concentric or substantially concentric with the mechanisms of the cap assembly such as the electrolyte injection port 6, the vent hole 24, and the metal electrical contact surface 5. The completed electrochemical energy storage device can incorporate two electrodes housed in the cell can 1. The cap 1-5 assembly can include an electrical contact surface 5 constructed to enable electrical transmission from the outer surface 2-1 to at least one of the electrodes. The electrical contact surface 5 can be arranged (a) concentrically with the electrolyte injection port 6 and (b) closer to the outer peripheral edge 2-3 than the position of the electrolyte injection port 6, as shown in FIG. 3. The electrical insulator 4 can electrically insulate the electrical contact surface 5 from the lid 2 and the outer peripheral edge 2-3 of the lid.

[0029] As shown in FIG. 3, the outer peripheral edge 2-3 may be circular or substantially circular. The vent hole 24 can substantially surround the periphery of the electrolyte injection port 6 and can further include a double vent notch. Similarly, the electrical contact surface 5 can substantially surround the periphery of the electrolyte injection port 6.

[0030] The mechanisms of the cap assembly (i.e., the electrolyte injection port 6, the electrical contact surface 5, and the vent hole 24) do not necessarily have to be exactly concentric, but can be configured to be substantially concentric such that the diameter of mechanism 1 is inside the diameter of mechanism 2 and the diameter of mechanism 2 is inside the diameter of mechanism 3. For example, the electrolyte injection port 6 can have an outer diameter A, the metal electrical contact surface 5 can have an outer diameter B, and the vent hole 24 can have an outer diameter C, and thus the dimensions of A, B, and C are such that A < B < C.

[0031] The mechanisms of the cap assembly 1-5 are preferably circular to facilitate machining and assembly, but the mechanisms of the cap assembly, i.e., the electrolyte injection port 6, the vent hole 24, and the metal electrical contact surface 5, may be of various shapes. A substantially concentric mechanism can also be defined as one in which the entire of one mechanism is within the outer geometry of the next larger mechanism.

[0032] Figs. 4A to 4B show a cap assembly 1-5 provided with a poppet valve, by which it is advantageous that a pressurized electrolytic solution (or solvent) can be injected into the cell can body 1, the port 6 can be automatically sealed when the injection process is completed, and leakage of the pressurized electrolytic solution (or solvent) can be prevented. The poppet valve specifically includes a poppet 7, a compression spring 9 connected to the poppet 7, and a valve seat 7-3. The electrolytic solution injection port 6 thus has an open configuration (Fig. 4B) characterized in that the poppet 7 compresses the spring 9, removes the poppet 7 from the valve seat 7-3, and forms a port opening 6-1 between the outer surface 2-1 and the inner surface 2-2, and a sealing configuration (Fig. 4A) characterized in that the spring 9 is decompressed with respect to the open configuration, the poppet 7 is fitted with the valve seat 7-3, and a hermetically sealed state for sealing the closed port opening 6-1 is formed, and can have two types of configurations. The open configuration can be actuated by a force 7-2 applied to the poppet 7. The poppet can have a portion 7-1 extending from the outer surface 2-1 as shown. The poppet 7 can also include a wedge-shaped stopper 8 that limits the movement of the poppet 7. The force 7-2 can be a mechanical force applied by a structure similar to the valve structure of a bicycle pump. Instead of or in combination with the mechanical force, the force 7-2 can be a pressure applied by a pressurized gas. The poppet 7 is removed from the valve seat 7-3 by a force 7-2 greater than the force applied by the compression spring 7-4 and the pressure 7-5 due to the gas acting on the poppet 7 from the inner surface 2-3.

[0033] Fig. 5 shows an electrolytic solution injection port 6 provided with a metal tube 10 that can be used to facilitate the intake of an electrolytic solution (or solvent) into the cell.

[0034] Figures 6A to 6B show a cap assembly 1-5 provided with a ball valve, by which a pressurized electrolytic solution (or solvent) is injected into the cell can housing 1, and when the injection process is completed, the port 6 is automatically sealed, which is advantageous because it can prevent the pressurized electrolytic solution (or solvent) from leaking. Specifically, the ball valve includes a ball 11, a compression spring 12 connected to the ball 11, and a valve seat 11-1. The electrolytic solution injection port 6 thus has an open configuration (Figure 6B) characterized in that the ball 11 compresses the compression spring 12, removes the ball 11 from the valve seat 11-1, and forms a port opening 6-1 between the outer surface 2-1 and the inner surface 2-2, and a sealing configuration (Figure 6A) characterized in that the compression of the compression spring 12 is released with respect to the open configuration, the ball 11 is fitted with the valve seat 11-1, and a hermetically sealed state is formed to seal the closed port opening 6-1. The open configuration can be actuated by the injection pressure 15-1 applied to the ball from the outer surface 2-1, and the injection pressure is at least greater than the cell can (internal gas) pressure 15-2 applied to the ball 11 from the inner surface 2-2. Since the injection pressure 15-1 must also overcome the force 11-4 of the compression spring, it must be greater than the cell can (internal gas) pressure 15-2. The movement of the ball 11 can be restricted using a retainer 13. The ball 11 may be made of rubber or other flexible material in order to form a leak-free sealing state with the valve seat 11-1.

[0035] Figure 6C shows a cap assembly of a ball valve provided with a welding plug 14 for permanently sealing the electrolytic solution injection port 6.

[0036] Figures 7A to 7B show a cap assembly 1-5 provided with a conical plug valve, whereby it is advantageous that pressurized electrolytic solution (or solvent) can be injected into the cell can housing 1, and when the injection process is completed, the port 6 can be automatically sealed to prevent the pressurized electrolytic solution (or solvent) from leaking. Specifically, the conical plug valve includes a conical plug 15 and a rubber valve seat 16. The electrolytic solution injection port 6 thus has an open configuration (Figure 7B) characterized by removing the conical plug 15 from the rubber valve seat 16 to form a port opening 6-1 between the outer surface 2-1 and the inner surface 2-2, and a sealing configuration (Figure 7A) characterized by the conical plug 15 being fitted with the rubber valve seat 16 to form a hermetic sealing state that seals the closed port opening 6-1. The open configuration can be actuated by the injection pressure 15-1 applied to the conical plug 15 from the outer surface 2-1, and the injection pressure is at least greater than the cell can (internal gas) pressure 15-2 applied to the conical plug 15 from the inner surface 2-2.

[0037] Figures 8, 10, and 11 show the electrolytic solution inlet 6 sealed by a set screw 18 (Figure 8), a rubber plug 19 (Figure 8), an expansion plug 22 (Figure 10), and a metal plug 25 (Figure 11).

[0038] Figs. 9A to 9B show a cap assembly 1-5 provided with a rubber stopper type valve. By this, when pressurized electrolytic solution (or solvent) is injected into the cell can housing 1 and the injection process is completed, the port 6 is automatically sealed, which is advantageous because it can prevent the pressurized electrolytic solution (or solvent) from leaking. Specifically, the rubber stopper type valve includes a rubber stopper 21, a spring tab 20 that contacts the rubber stopper 21, and a valve seat 21-1. The electrolytic solution injection port 6 thus has an open configuration (Fig. 9B) characterized in that the rubber stopper 21 spreads the spring tab 20 and removes the rubber stopper 21 from the valve seat 21-1 to form a port opening 6-1 between the outer surface 2-1 and the inner surface 2-2, and a sealing configuration (Fig. 9A) characterized in that the rubber stopper 21 fits with the valve seat 21-1 to form an airtight sealing state that seals the closed port opening 6-1, and can have two types of configurations. The open configuration can be actuated by the injection pressure 21-2 applied to the rubber stopper 21 from the outer surface 2-1, and the injection pressure is at least greater than the cell can (internal gas) pressure 21-3 applied to the rubber stopper 21 from the inner surface 2-2. Since the injection pressure 21-2 must also overcome the spring force 21-4 of the tab, it must be greater than the cell can (internal gas) pressure 21-3.

[0039] Figs. 12A and 12B show a cap assembly provided with a shoulder 29 along the outer peripheral edge 2-3. The shoulder 29 is adapted to contact the cell can housing 1 along two mutually perpendicular surfaces (29-1 and 29-2). By these two surfaces, the connection between the cap assembly 1-5 and the cell can housing 1 is surely and strongly leak-proof, and the cap assembly and the cell can housing can be integrally welded.

[0040] Fig. 13 is characterized by including a shrink fit or interference fit ring 28 that locks onto the metal electrical contact surface 5. This is assembled such that the ring 28 compresses the rubber gasket 3 to create a sealing state, and the rubber gasket prevents the leakage of electrolytic solution from within the cell can housing 1 and acts as an electrical insulator. The shrink fit or interference fit ring 28 may also be concentric or substantially concentric with the mechanisms of the cap assembly such as the electrolytic solution injection port 6, the vent hole 24, and the metal electrical contact surface 5.

[0041] The aforementioned cap assemblies 1-5 can be used to more efficiently manufacture an electrochemical energy storage device. The cell can body 1 can fit with a positive electrode, a negative electrode, and a separator. The cell can body 1 can optionally further include one or more salts and one or more additives. Then, the cap assemblies 1-5 can be sealed to the cell can body 1. A pressurized liquefied gas solvent can be injected into the interior of the cell can body 1 through the electrolyte injection port 6. Alternatively, a pressurized electrolyte can be premixed with one or more salts and one or more additives and injected into the interior of the cell can body 1 through the electrolyte injection port 6. Once the injection of the electrolyte is completed, the cell is removed from the injection port 6, and the cap assemblies 1-5 are automatically sealed to prevent gas leakage.

[0042] The completed electrochemical energy storage device can be characterized as comprising a liquefied gas electrolyte composed of one or more salts, additives, or solvents, and the one or more solvents are liquefied gas solvents having a vapor pressure exceeding 100 kPa at a temperature of 293.15K. The liquefied gas solvent may include one or more of fluoromethane, difluoromethane, trifluoromethane, fluoroethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, fluoroethylene, difluoroethylene, trifluoroethylene, tetrafluoroethylene, chloromethane, chloroethane, chloroethene, methane, ethane, propane, n-butane, isobutane, pentane, hexane, heptane, octane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, ethene, propene, butene, pentene, heptene, octene, isomers thereof, saturated halogenated hydrocarbons, unsaturated halogenated hydrocarbons, and isomers of halogenated hydrocarbons.

[0043] Similarly, while the operations are shown in the drawings in a particular order, this should not be understood as requiring that the operations be performed in the particular order or sequence shown in order to achieve the desired result, or that all of the operations shown be performed. Further, the separation of the various system components in the embodiments described in this patent document should not be understood as requiring such separation in all embodiments. Only a few examples and illustrations are provided, and based on what is described and illustrated in this patent document, other embodiments, extensions, and variations can be made without departing from the scope and spirit of the invention.

[0044] This patent document contains many details, but these should not be construed as limiting the scope of the invention or what may be claimed, but rather as explanations and interpretations of mechanisms that may be specific to particular embodiments of a particular invention. In this patent document, particular mechanisms described in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, the various mechanisms described in the context of a single embodiment can also be implemented in separate or suitable partial combinations in multiple embodiments. The mechanisms are further described above as acting in a particular combination and may initially even be claimed as such, but one or more of the mechanisms from the claimed combination can, in some cases, be excised from that combination, and the claimed combination may be directed to partial combinations or variations of partial combinations.

Claims

1. A cap assembly (1-5) constructed to seal a cell can housing (1) having two electrodes, wherein the cap assembly (1-5) comprises: an outer surface (2-1), an inner surface (2-2), and an outer peripheral edge (2-3); an electrolyte injection port (6) forming a port opening (6-1) between the outer surface (2-1) and the inner surface (2-2); a vent hole (24) constructed to form a vent hole opening (24-1) from the inner surface (2-2) to the outer surface (2-1) when a ventilation pressure difference is achieved between the outer surface pressure and the inner surface pressure; electrical insulators (4, 3); and wherein: the vent hole (24) is arranged (a) concentrically with the electrolyte injection port (6) and (b) closer to the outer peripheral edge (2-3) than the position of the electrolyte injection port (6); the electrical insulators (4, 3) are constructed to electrically insulate the vent hole (24) from the electrolyte injection port (6). [[ / ]] A cap assembly.

2. The cap assembly according to claim 1, wherein the outer peripheral edge (2-3) is circular.

3. The cap assembly according to claim 1, wherein the vent hole (24) surrounds the electrolyte injection port (6).

4. The cap assembly according to claim 1, wherein the vent hole (24) comprises a notch or a double notch.

5. The cap assembly according to claim 1, further comprising an electrical contact surface (5) constructed to enable electrical transmission from the outer surface (2-1) to one of the electrodes, and wherein: the electrical contact surface (5) is arranged (a) concentrically with the electrolyte injection port (6) and (b) closer to the outer peripheral edge (2-3) than the position of the electrolyte injection port (6).

6. The cap assembly according to claim 5, wherein the electrical contact surface (5) surrounds the electrolyte injection port (6).

7. The cap assembly according to claim 5, wherein the vent hole (24) is arranged closer to the outer peripheral edge (2-3) than the electrical contact surface (5).

8. The cap assembly according to claim 6, wherein the electrical insulators (4, 3) are constructed to electrically insulate the electrical contact surface (5) from the outer peripheral edge (2-3).

9. The cap assembly according to claim 8, wherein the electrical insulator (4) comprises a rubber gasket (3).

10. The cap assembly according to claim 1, further comprising a welded joint (23) adapted to connect the cell can housing (1) to the outer peripheral edge (2-3).

11. The cap assembly according to claim 1, wherein the outer peripheral edge (2-3) comprises a shoulder (29) adapted to contact the cell can housing (1) along two mutually perpendicular surfaces (29-1, 29-2).

12. The cap assembly according to claim 1, wherein the injection port (6) is sealed by a stop screw (18), an expansion plug (22), a metal plug (25), or a welding plug (14).

13. The cap assembly according to claim 1, wherein the electrolyte injection port (6) comprises a metal tube (10) extending in a direction away from the outer surface (2-1).

14. A cap lid (2) having the outer peripheral edge (2-3), a rubber gasket (3), a ring (28), and further comprising, wherein the ring (28) presses against the cap lid (2) to compress the rubber gasket (3), The cap assembly according to claim 1, wherein the ring (28) is a shrink-fit ring or a crimping ring.

15. The cap assembly according to claim 1, wherein the electrolyte injection port (6) is provided with a valve, and the valve is configured to: (a) form the port opening (6-1) when pressure is applied to the valve from the outer surface (2-1); and (b) close the port opening (6-1) to form an airtight seal when the pressure from the outer surface (2-1) is removed.

16. The electrolyte injection port is a poppet (7) having a portion (7-1) extending in a direction away from the outer surface (2-1), a compression spring (9) connected to the poppet (7), and a valve seat (7-3), and the electrolyte injection port (6) is characterized by an open configuration in which the poppet compresses the spring (9) to remove the poppet (7) from the valve seat (7-3) and form the port opening (6-1) between the outer surface (2-1) and the inner surface (2-2); and a sealed configuration in which the spring (9) is decompressed relative to the open configuration, the poppet (7) is fitted with the valve seat (7-3), and an airtight seal is formed to seal the closed port opening (6-1). It has two types of configurations, The cap assembly according to claim 1, wherein the open configuration is actuated by a force (7-2) applied to the portion (7-1) of the poppet.

17. The cap assembly according to claim 16, wherein the poppet (7) comprises a wedge stopper (8) configured to limit the movement of the poppet (7).

18. The electrolyte injection port (6) comprises a ball (11), a compression spring (12) connected to the ball (11), and a valve seat (11-1) and the electrolyte injection port (6) has an open configuration characterized in that the ball (11) compresses the compression spring (12) to remove the ball from the valve seat (11-1) and form the port opening (6-1) between the outer surface (2-1) and the inner surface (2-2); and a sealing configuration characterized in that the compression of the compression spring (12) is released with respect to the open configuration, the ball (11) is fitted to the valve seat (11-1), and a hermetically sealed state is formed in which the closed port opening (6-1) is sealed. The cap assembly has two types of configurations, wherein the open configuration is actuated by an injection pressure (11-2) applied from the outer surface (2-1) to the ball (11), which is greater than at least the cell can pressure (11-3) applied from the inner surface (2-2) to the ball (11), according to claim 1.

19. The cap assembly according to claim 18, further comprising a retainer (13) configured to limit the movement of the ball (11).

20. The electrolyte injection port (6) comprises a conical plug (15) and a rubber valve seat (16) and the electrolyte injection port (6) has an open configuration characterized in that the conical plug (15) is removed from the rubber valve seat (16) to form the port opening (6-1) between the outer surface (2-1) and the inner surface (2-2); and a sealing configuration characterized in that the conical plug (15) is fitted to the rubber valve seat (16) to form a hermetically sealed state in which the closed port opening (6-1) is sealed. The cap assembly has two types of configurations, wherein the open configuration is actuated by an injection pressure (15-1) applied from the outer surface (2-1) to the conical plug (16), which is greater than at least the cell can pressure (15-2) applied from the inner surface (2-2) to the conical plug (16), according to claim 1.

21. The electrolyte injection port (6) comprises a rubber plug (21), a spring tab (20) in contact with the rubber plug (21), and a valve seat (21-1) and the electrolyte injection port (6) The rubber stopper (21) expands the spring tab (20), removes the rubber stopper from the valve seat (21-1), and forms the port opening (6-1) between the outer surface (2-1) and the inner surface (2-2), characterized by an open configuration; The rubber stopper (21) fits with the valve seat (21-1) to form a hermetic sealing state that seals the closed port opening (6-1), characterized by a sealing configuration It has two types of configurations, The open configuration is actuated by an injection pressure (21-2) applied to the rubber stopper (21) from the outer surface (2-1), which is greater than at least the cell can pressure (21-3) applied to the rubber stopper (21) from the inner surface (2-2), of the cap assembly according to claim 1.

22. A cap assembly (1-5), An outer surface (2-10), an inner surface (2-2), and an outer peripheral edge (2-3); An electrolyte injection port (6) that forms a port opening (6-1) between the outer surface (2-1) and the inner surface (2-2); A vent hole (24) constructed to form a vent hole opening (24-1) from the inner surface (2-2) to the outer surface (2-1) when a ventilation pressure difference is achieved between the outer surface pressure and the inner surface pressure; An electrical insulator (4, 3) Comprising, The vent hole (24) is arranged (a) concentrically with the electrolyte injection port (6) and (b) closer to the outer peripheral edge (2-3) than the position of the electrolyte injection port (6); The electrical insulator (4, 3) is constructed to electrically insulate the vent hole (24) from the electrolyte injection port (6). A cap assembly (1-5); A cell can housing (1) containing pressurized electrolyte Comprising, An electrochemical energy storage device in which the cap assembly (1-5) and the cell can housing (1) form a hermetic sealing state that prevents the electrolyte from leaking during normal operating conditions.

23. The electrochemical energy storage device according to claim 22, wherein the electrolyte comprises a salt and a solvent, and the solvent is a liquefied gas having a vapor pressure exceeding an atmospheric pressure of 100 kPa at a temperature of 293.15 K.

24. The electrochemical energy storage device according to claim 23, wherein the solvent is selected from the group consisting of fluoromethane, difluoromethane, trifluoromethane, fluoroethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, fluoroethylene, difluoroethylene, trifluoroethylene, tetrafluoroethylene, chloromethane, chloroethane, chloroethene, methane, ethane, propane, n-butane, isobutane, pentane, hexane, heptane, octane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, ethene, propene, butene, pentene, heptene, octene, isomers thereof, saturated halogenated hydrocarbons, unsaturated halogenated hydrocarbons, and isomers of halogenated hydrocarbons.

25. The electrochemical energy storage device according to claim 24, wherein the electrochemical energy storage device is a battery or a capacitor.

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