JP7704479B2 - Caps for electrochemical cells - Google Patents

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is also related to the following filed applications, the contents of each of which are incorporated herein by reference in their entirety: PCT/US20/048660, filed August 30, 2020; PCT/US20/020547, filed February 29, 2020; PCT/US20/048661, filed August 30, 2020; PCT/US19/032413, filed May 15, 2019; PCT/US19/032414, filed May 15, 2019; PCT/US14/066015, filed November 17, 2014; PCT/US20/026086, filed April 1, 2020; PCT/US20/026087, filed April 1, 2017; PCT / US17 / 029821 filed on May 27, 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.

This application claims priority to U.S. Provisional Patent Application No. 63/306,393, filed February 3, 2022, the entire contents of which are incorporated by reference.

Embodiments of the present invention relate to electrochemical cells, such as batteries and capacitors, mechanical design of electrochemical cells, and electrolyte injection methods for manufacturing.

Electrochemical energy storage devices such as batteries and double layer capacitors are commonly sold in four form factors: prismatic, pouch, button, and cylindrical cells. These devices or cells have external metallic electrical contacts for both the positive and negative electrodes to carry electrical current through a circuit. The cell housing often also features a vent, burst disc, rupture disc, or another mechanism to relieve internal pressure that develops within the cell. The cell housing may also feature an injection port for injecting electrolyte into the interior of the cell that contains the positive electrode, negative electrode, and separator.

Cylindrical cells do not have an injection port in the cap assembly since such a mechanism is not necessary. In practice, the electrolyte is first injected into the cell in a first step, and then the cap assembly is attached to the cell in a second step.

However, particularly for liquefied gas electrolytes, it is advantageous to secure 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 secure the cap in place as a first step, followed by injection of the electrolyte as a second step, and instantaneous sealing of the cell without releasing the electrolyte pressure to prevent electrolyte evaporation as a third step.

What is needed is a cell design that simplifies the process in a cost-effective manner. Presented herein is a cap assembly with an electrolyte injection port, vent, and metal electrical contact surface. The cap assembly can be attached to the cell can prior to electrolyte gas injection, simplifying the manufacturing process. Moreover, these features (i.e., electrolyte injection port, vent, and metal electrical contact surface) can have a relatively circular geometry, as may be measured for geometric center and geometric diameter, and are referred to throughout this invention. Even more beneficial from a cap assembly mass and volume standpoint is to have the centers of all three cap assembly features concentric to minimize the cap footprint while maintaining high device performance and functionality. This concentric configuration also minimizes the volume, mass, and cost of the cap assembly.

Disclosed herein is a cap assembly that creates an airtight 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 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 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 injection port, and (b) closer to the outer periphery than the location of the electrolyte injection port.

The outer periphery may be circular or nearly circular. The vent may substantially circumferentially surround the electrolyte injection port and may further include a dual vent cutout.

The cell can housing can house two electrodes, and the cap assembly can include an electrical contact surface constructed to enable electrical transmission from an exterior surface to one of the electrodes. The electrical contact surface can be located (a) concentrically with the electrolyte injection port and (b) closer to the outer periphery than the location of the electrolyte injection port. The electrical contact surface can substantially circumscribe the electrolyte injection port. An electrical insulator can electrically insulate the electrical contact surface from the outer periphery.

The cap assembly may include a weld joint adapted to connect the cell can housing to the outer periphery. The outer periphery may include a shoulder adapted to contact the cell can housing along two mutually perpendicular faces.

The fill port can be sealed by a set screw, expansion plug, metal plug, or welded plug. The fill port can also include a metal tube extending away from the exterior surface that can be used to fill the cell can housing with electrolyte.

The outer periphery may be part of the cap lid. The ring may be pressed against the cap lid to compress the rubber gasket. The ring may be a shrink-fit ring or a crimp ring, and the rubber gasket may provide electrical insulation.

The electrolyte injection port may include a valve that allows electrolyte to be filled into the cell can housing.

One non-limiting example is an electrolyte injection port that includes a poppet, a compression spring coupled to the poppet, and a valve seat. The electrolyte injection port can have two configurations: an open configuration, in which the poppet compresses the spring, disengaging the poppet from the valve seat to form a port opening between the exterior and interior surfaces, and a sealed configuration, in which the spring decompresses to the open configuration, engaging the poppet with the valve seat to form an airtight seal that seals the closed port opening. The open configuration can be actuated by a force on the poppet. The poppet can also include a wedge-shaped stop that limits the movement of the poppet.

A second non-limiting example is an electrolyte injection port with a ball, a compression spring coupled to the ball, and a valve seat. The electrolyte injection port can have two configurations: an open configuration in which the ball compresses the compression spring, disengaging the ball from the valve seat to form a port opening between the exterior and interior surfaces, and a sealed configuration in which the compression spring is decompressed relative to the open configuration, engaging the ball with the valve seat to form an airtight seal sealing the closed port opening. The open configuration can be actuated by an injection pressure exerted on the ball from the exterior surface, the injection pressure being at least greater than the cell can pressure exerted on the ball from the interior surface. A retainer can be used to limit the movement of the ball.

A third non-limiting example is an electrolyte injection port with a conical plug and a rubber valve seat. The electrolyte injection port can have two configurations: an open configuration in which the conical plug is removed from the rubber valve seat to form a port opening between the exterior and interior surfaces, and a sealed configuration in which the conical plug is mated with the rubber valve seat to form an airtight seal that seals the closed port opening. The open configuration can be actuated by an injection pressure applied to the conical plug from the exterior surface, the injection pressure being at least greater than the cell can pressure applied to the conical plug from the interior surface.

A fourth non-limiting example is an electrolyte injection port with a rubber plug, a spring tab in contact with the rubber plug, and a valve seat. The electrolyte injection port can have two configurations: an open configuration in which the rubber plug spreads the spring tab and disengages the rubber plug from the valve seat to form a port opening between the exterior and interior surfaces, and a sealed configuration in which the rubber plug engages the valve seat to form an airtight seal sealing the closed port opening. The open configuration can be actuated by an injection pressure exerted on the rubber plug from the exterior surface, the injection pressure being at least greater than the cell can pressure exerted on the rubber plug from the interior surface.

The injection port can be used to inject pressurized electrolyte (or solvent) into the cell can housing in each of the non-limiting examples above, and the port will automatically seal upon completion of the injection process to prevent the pressurized electrolyte (or solvent) from escaping.

Further aspects, alternatives, and variations that will be apparent to those skilled in the art are also disclosed herein and are specifically contemplated as part of the present invention. The invention is set forth solely in the claims granted by the Patent Office in this or a related application, and the following summary description of specific examples is not intended to limit, prescribe, or otherwise determine the scope of legal protection in any way.

FIG. 13 shows a cell can housing coupled to a cap assembly. FIG. 2 is a cross-sectional view of the cap assembly. FIG. FIG. 2 is a cross-sectional view of a cap assembly with a poppet-type valve in a sealing configuration. FIG. 2 is a cross-sectional view of a cap assembly with a poppet-type valve in an open configuration. FIG. 13 is a cross-sectional view of a cap assembly with a metal tube at the electrolyte injection port. FIG. 13 is a cross-sectional view of a cap assembly with a ball-type valve in a sealing configuration. FIG. 2 is a cross-sectional view of a cap assembly with a ball-type valve in an open configuration. FIG. 13 is a cross-sectional view of a cap assembly with a ball-type valve in a permanently sealed configuration. FIG. 13 is a cross-sectional view of a cap assembly with a cone-plug type valve in a sealing configuration. FIG. 2 is a cross-sectional view of a cap assembly with a cone-type valve in an open configuration. FIG. 13 is a cross-sectional view of the cap assembly with a set screw that blocks the electrolyte injection port. FIG. 1 is a cross-sectional view of a cap assembly with a rubber plug-type valve in a sealing configuration. FIG. 2 is a cross-sectional view of a cap assembly with a rubber plug-type valve in an open configuration. FIG. 13 is a cross-sectional view of the cap assembly with an expansion plug installed to block the electrolyte injection port. FIG. 13 is a cross-sectional view of the cap assembly with a metal plug installed to cover the electrolyte injection port. 12A is a cross-sectional view of a cap assembly with a shoulder where the cell cap lid abuts the cell housing can, and FIG. 12B is a close-up of the shoulder of FIG. 12A. FIG. 1 is a cross-sectional view of a cap assembly held together by a shrink or interference fit ring that engages with a metal electrical contact surface.

Reference is made herein to certain specific embodiments of the invention, including all the best modes contemplated by the inventors for carrying out the invention. Examples of these specific embodiments are illustrated in the accompanying drawings. While the invention will be described in conjunction with these specific embodiments, it will be understood that it is not intended to limit the invention to the embodiments described or illustrated. On the contrary, it is intended to cover alternatives, modifications, and equivalents that may be included within the spirit and scope of the invention as defined by the appended claims.

In the following description, numerous specific details are set forth to enable a thorough understanding of the present invention. Certain exemplary embodiments of the present invention may be practiced without some or all of these specific details. In other instances, operation of steps well known to those skilled in the art have not been described in detail so as not to unnecessarily obscure the present invention. Various techniques and mechanisms of the present invention may be described in the singular for clarity. However, it should be noted that some embodiments include multiple iterations of a technique or multiple mechanisms, unless otherwise noted. Similarly, the various steps of the methods shown and described herein may not necessarily be performed in the order shown, or at all, in a particular embodiment. Thus, some examples of the methods discussed herein may include more or fewer steps than shown or described. Furthermore, 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 imply a direct and unobstructed connection, since various other entities or steps may exist or occur between the two entities. Thus, unless otherwise noted, a connection shown does not necessarily imply a direct and unobstructed connection.

The following list of example features corresponds to the attached figures and is provided for ease of reference, where like reference numbers indicate corresponding features 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 rim 3 Rubber gasket 4 Electrical insulator 5 Metal electrical contact surface 6 Electrolyte injection port 6-1 Port opening 7 Poppet 7-1 Part extending from outer surface 7-2 Force on poppet 7-3 Valve seat for poppet 7-4 Compression spring force 7-5 Cell can (internal gas) pressure 8 Wedge stopper 9 Compression spring 10 Metal tube 11 Rubber ball 11-1 Valve seat for ball 11-2 Injection pressure 11-3 Cell can (internal gas) pressure 11-4 Compression spring force 12 Compression spring 13 Retainer 14 Welded plug 15 Conical plug 15-1 Injection pressure 15-2 Cell can pressure 16 Rubber O-ring seat 18 Set screw 19 Rubber plug 20 Spring tab 21 Rubber plug 21-1 Rubber plug seat 21-2 Filling pressure 21-3 Cell can (internal gas) pressure 21-4 Spring tab force 22 Expansion plug 23 Welded joint 24 Single vent notch 24-1 Vent opening 25 Metal plug 26 Double vent notch 27 Washer 28 Shrink fit or crimp ring 29 Shoulder 29-1 First shoulder surface 29-2 Second shoulder surface

Current state-of-the-art cylindrical cells generally do not have a fill port on the cap assembly, as the electrolyte is first filled into the cell as a first step, followed by the attachment of the cap assembly to the cell as a second step. In particular for liquefied gas electrolytes, it is beneficial to pre-fix the cap assembly to the cell housing as a first step, and then fill the cell with electrolyte as a second step. To prevent immediate evaporation of the liquefied gas electrolyte, it is necessary to fix the cap in place as a first step, followed by filling the electrolyte as a second step, and immediately seal the cell without releasing the electrolyte pressure to prevent electrolyte evaporation as a third step.

It would be even more beneficial from a manufacturing and cost perspective to have the electrolyte injection port, vent, and metal electrical contact surface all on the same cap assembly. These features may furthermore be measured by a geometric center and a geometric diameter and may have a relatively circular geometry, which is referred to throughout this invention. Even more beneficial from a cap assembly mass and volume perspective would be to have the centers of all three of these cap assembly features (electrolyte injection port, vent, and metal electrical contact surface) concentrically to minimize the cap footprint while maintaining high device performance and functionality. This type of concentric configuration would not only minimize the volume, mass, and cost of the cap assembly, but would also simplify manufacturing.

1-3, a novel cap assembly 1-5 is shown that creates an airtight seal with the cell can housing 1. The cap assembly 1-5 includes an exterior surface 2-1, an interior surface 2-2, and an outer periphery 2-3. An electrolyte or solvent can be introduced into the electrochemical energy storage device by injecting it through an electrolyte injection port 6. The electrolyte injection port 6 forms a port opening 6-1 between the exterior surface 2-1 and the interior surface 2-2. The cap assembly 1-5 also includes a vent 24 that is constructed to form a vent opening 24-1 from the interior surface 2-2 to the exterior surface 2-1 when a vent pressure differential is achieved or exceeded between the exterior surface pressure and the interior surface pressure. The vent 24 is a weakened portion of the lid 2 that can be designed to open at high internal cell pressures. This weakened portion of the lid 2 is a thinner portion of the lid 2 that can be formed by a notch in the lid 2, thus providing a weak spot where the cell can be vented under high internal cell pressures. The vent hole 24 is (a) concentric with the electrolyte injection port 6, and (b) positioned closer to the outer periphery 2-3 than the electrolyte injection port 6.

The cap assembly 1-5 can be coupled to the cell housing 1 via a welded joint 23. The cell housing 1 can also be circular in geometry and can be concentric or nearly concentric with features of the cap assembly such as the electrolyte injection port 6, the vent 24, and the metal electrical contact surface 5. The completed electrochemical energy storage device can incorporate two electrodes housed in the cell housing 1. The cap 1-5 assembly can include an electrical contact surface 5 constructed to allow electrical transmission from the outer surface 2-1 to at least one of the electrodes. The electrical contact surface 5 can be located (a) concentric with the electrolyte injection port 6 and (b) closer to the outer periphery 2-3 than the location of the electrolyte injection port 6, as shown in FIG. 3. An electrical insulator 4 can electrically insulate the electrical contact surface 5 from the lid 2 and the outer periphery 2-3 of the lid.

As shown in FIG. 3, the outer periphery 2-3 may be circular or nearly circular. The vent 24 may substantially circumferentially surround the electrolyte injection port 6 and may further include a dual vent cutout. The electrical contact surface 5 may similarly substantially circumferentially surround the electrolyte injection port 6.

The features of the cap assembly (i.e., electrolyte injection port 6, electrical contact surface 5, and vent 24) need not be strictly concentric, but can be configured to be approximately concentric, such that the diameter of feature 1 is inside the diameter of feature 2, which is inside the diameter of feature 3. For example, electrolyte injection port 6 can have an outer diameter A, metal electrical contact surface 5 can have an outer diameter B, and vent 24 can have an outer diameter C, such that the dimensions of A, B, and C are A<B<C.

The features of the cap assemblies 1-5 are preferably circular for ease of machining and assembly, however, the features of the cap assemblies, i.e., electrolyte injection port 6, vent hole 24, and metal electrical contact surface 5, may be of various shapes. Nearly concentric features may also be defined as one feature entirely within the outer geometry of the next larger feature.

Figures 4A-4B show a cap assembly 1-5 with a poppet-type valve, which advantageously allows pressurized electrolyte (or solvent) to be injected into the cell can housing 1 and automatically seals the port 6 upon completion of the injection process to prevent leakage of the pressurized electrolyte (or solvent). The poppet-type valve specifically includes a poppet 7, a compression spring 9 connected to the poppet 7, and a valve seat 7-3. The electrolyte injection port 6 can thus have two configurations: an open configuration (Figure 4B) characterized by the poppet 7 compressing the spring 9 and removing the poppet 7 from the valve seat 7-3 to form a port opening 6-1 between the outer surface 2-1 and the inner surface 2-2, and a sealed configuration (Figure 4A) characterized by the spring 9 being decompressed relative to the open configuration, engaging the poppet 7 with the valve seat 7-3 to form an airtight seal sealing the closed port opening 6-1. The open configuration can be actuated by a force 7-2 on the poppet 7. The poppet may have a portion 7-1 extending from the outer surface 2-1 as shown. The poppet 7 may also include a wedge-shaped stop 8 that limits the movement of the poppet 7. The force 7-2 may be a mechanical force exerted by a structure similar to the valve structure of a bicycle pump. The force 7-2 may be a pressure exerted by a pressurized gas instead of or in combination with a mechanical force. The poppet 7 is removed from the valve seat 7-3 with the force 7-2 being greater than the force exerted 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.

Figure 5 shows an electrolyte injection port 6 with a metal tube 10 that can be used to facilitate the introduction of electrolyte (or solvent) into the cell.

6A-6B show a cap assembly 1-5 with a ball-type valve, which advantageously allows pressurized electrolyte (or solvent) to be injected into the cell can housing 1 and automatically seals the port 6 when the injection process is completed to prevent leakage of the pressurized electrolyte (or solvent). The ball-type valve specifically includes a ball 11, a compression spring 12 connected to the ball 11, and a valve seat 11-1. The electrolyte injection port 6 can thus have two configurations: an open configuration (FIG. 6B) characterized in that the ball 11 compresses the compression spring 12 and removes the ball 11 from the valve seat 11-1 to form a port opening 6-1 between the outer surface 2-1 and the inner surface 2-2, and a sealed configuration (FIG. 6A) characterized in that the compression spring 12 is decompressed relative to the open configuration, and the ball 11 engages with the valve seat 11-1 to form an airtight seal sealing the closed port opening 6-1. The open configuration can be actuated by an injection pressure 15-1 applied to the ball from the outer surface 2-1, which is at least greater than the cell can (internal gas) pressure 15-2 applied to the ball 11 from the inner surface 2-2. The injection pressure 15-1 must be greater than the cell can (internal gas) pressure 15-2 because it must also overcome the compression spring force 11-4. A retainer 13 can be used to limit the movement of the ball 11. The ball 11 may be made of rubber or other flexible material to form a leak-tight seal with the valve seat 11-1.

Figure 6C shows a ball valve cap assembly with a welded plug 14 to permanently seal the electrolyte injection port 6.

7A-7B show a cap assembly 1-5 with a cone plug type valve, which advantageously allows pressurized electrolyte (or solvent) to be injected into the cell can housing 1 and automatically seals the port 6 upon completion of the injection process to prevent leakage of the pressurized electrolyte (or solvent). The cone plug type valve specifically comprises a cone plug 15 and a rubber valve seat 16. The electrolyte injection port 6 can thus have two configurations: an open configuration (FIG. 7B) in which the cone plug 15 is removed 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 sealed configuration (FIG. 7A) in which the cone plug 15 mates with the rubber valve seat 16 to form an airtight seal sealing the closed port opening 6-1. The open configuration can be actuated by an injection pressure 15-1 applied to the conical plug 15 from the outer surface 2-1, the injection pressure being at least greater than the cell can (internal gas) pressure 15-2 applied to the conical plug 15 from the inner surface 2-2.

Figures 8, 10, and 11 show the electrolyte injection port 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).

9A-9B show a cap assembly 1-5 with a rubber plug type valve, which advantageously allows pressurized electrolyte (or solvent) to be injected into the cell can housing 1 and automatically seals the port 6 upon completion of the injection process to prevent leakage of the pressurized electrolyte (or solvent). The rubber plug type valve specifically includes a rubber plug 21, a spring tab 20 in contact with the rubber plug 21, and a valve seat 21-1. The electrolyte injection port 6 can thus have two configurations: an open configuration (FIG. 9B) in which the rubber plug 21 spreads the spring tab 20 and removes the rubber plug 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 sealed configuration (FIG. 9A) in which the rubber plug 21 mates with the valve seat 21-1 to form an airtight seal sealing the closed port opening 6-1. The open configuration can be actuated by an injection pressure 21-2 applied to the rubber plug 21 from the outer surface 2-1, which is at least greater than the cell can (internal gas) pressure 21-3 applied to the rubber plug 21 from the inner surface 2-2. The injection pressure 21-2 must also overcome the tab spring force 21-4, so it must be greater than the cell can (internal gas) pressure 21-3.

Figures 12A and 12B show a cap assembly with a shoulder 29 along the outer periphery 2-3. The shoulder 29 is adapted to contact the cell can housing 1 along two mutually perpendicular faces (29-1 and 29-2). These two faces ensure a strong, leak-free connection between the cap assembly 1-5 and the cell can housing 1, and the cap assembly and cell can housing can be welded together.

13 features a shrink or interference fit ring 28 that engages the metal electrical contact surface 5. It is assembled such that the ring 28 compresses the rubber gasket 3 to create a seal that prevents electrolyte leakage from within the cell can housing 1 and acts as an electrical insulator. The shrink or interference fit ring 28 may also be concentric or nearly concentric with features of the cap assembly such as the electrolyte injection port 6, the vent 24, and the metal electrical contact surface 5.

The cap assembly 1-5 described above can be used to more efficiently manufacture electrochemical energy storage devices. The cell can housing 1 can be fitted with the positive and negative electrodes and the separator. The cell can housing 1 can optionally further comprise one or more salts and one or more additives. The cap assembly 1-5 can then be sealed to the cell can housing 1. A pressurized liquefied gas solvent can be injected into the interior of the cell can housing 1 through the electrolyte injection port 6. Alternatively, pressurized electrolyte can be premixed with the salt and one or more additives and injected into the interior of the cell can housing 1 through the electrolyte injection port 6. The cell is removed from the injection port 6 once electrolyte injection is complete, and the cap assembly 1-5 automatically seals to prevent gas leakage.

The finished electrochemical energy storage device may feature a liquefied gas electrolyte comprised of one or more salts, additives, or solvents, where the one or more solvents are liquefied gas solvents having a vapor pressure in excess of atmospheric pressure of 100 kPa at a temperature of 293.15 K. 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, heptane, octene, isomers thereof, saturated halogenated hydrocarbons, unsaturated halogenated hydrocarbons, and isomers of halogenated hydrocarbons.

Similarly, although operations are shown in the figures in a particular order, this should not be understood as requiring that such operations be performed in the particular order or sequence shown, or that all of the operations shown be performed, to achieve desired results. Furthermore, the separation of 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 implementations and examples have been described, and other implementations, extensions, and variations can be made based on what is described and illustrated in this patent document without departing from the scope and spirit of the invention.

Although this patent document contains many details, these should not be construed as limiting the scope of the invention or what may be claimed, but rather as descriptions of features that may be specific to certain embodiments of a particular invention. Certain features described in this patent document in the context of separate embodiments may also be realized in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be realized in multiple embodiments, either separately or in suitable subcombinations. Features may further be described above as acting in a particular combination, and even initially claimed as such, but one or more features from a claimed combination may in some cases be cut out of the combination, and the claimed combination may be directed to a subcombination or a variation of the subcombination.

Claims (25)

A cap assembly (1-5) constructed to seal a cell can housing (1) having two electrodes, said cap assembly (1-5) comprising:
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 (24) constructed to form a vent opening (24-1) from said inner surface (2-2) to said outer surface (2-1) when a vent pressure differential is established between an outer surface pressure and an inner surface pressure;
and an electrical insulator (4, 3),
the vent hole (24) is (a) concentric with the electrolyte injection port (6) and (b) disposed closer to the outer circumferential edge (2-3) than the electrolyte injection port (6);
The cap assembly, wherein the electrical insulator (4, 3) is constructed to electrically insulate the vent hole (24) from the electrolyte injection port (6). The cap assembly of claim 1, wherein the outer peripheral edge (2-3) is circular. The cap assembly of claim 1, wherein the vent hole (24) surrounds the electrolyte injection port (6). The cap assembly of claim 1, wherein the vent hole (24) comprises a notch or a double notch. an electrical contact surface (5) constructed to enable electrical transmission from said outer surface (2-1) to one of said electrodes;
Equipped with
2. The cap assembly of claim 1, wherein the electrical contact surface (5) is disposed (a) concentrically with the electrolyte injection port (6) and (b) closer to the outer circumferential edge (2-3) than the location of the electrolyte injection port (6). The cap assembly of claim 5, wherein the electrical contact surface (5) surrounds the electrolyte injection port (6). The cap assembly of claim 5, wherein the vent hole (24) is disposed closer to the outer periphery (2-3) than to the electrical contact surface (5). The cap assembly of claim 6 , wherein an electrical insulator (4,3) is constructed to electrically insulate said electrical contact surface (5) from said outer periphery (2-3). The cap assembly of claim 8, wherein the electrical insulator (4) comprises a rubber gasket (3). The cap assembly of claim 1, further comprising a weld joint (23) adapted to connect the cell can housing (1) to the outer periphery (2-3). The cap assembly of claim 1, wherein the outer peripheral edge (2-3) has a shoulder (29) adapted to contact the cell can housing (1) along two mutually perpendicular faces (29-1, 29-2). The cap assembly of claim 1, wherein the injection port (6) is sealed by a set screw (18), an expansion plug (22), a metal plug (25), or a welded plug (14). The cap assembly of claim 1, wherein the electrolyte injection port (6) comprises a metal tube (10) extending in a direction away from the outer surface (2-1). A cap lid (2) having the outer peripheral edge (2-3);
A rubber gasket (3);
and a ring (28).
The ring (28) presses against the cap lid (2) to compress the rubber gasket (3);
The cap assembly of claim 1, wherein the ring (28) is a shrink fit ring or a crimp ring. The cap assembly of claim 1, wherein the electrolyte injection port (6) includes a valve that is constructed 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. 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).
The electrolyte injection port (6) is
an open configuration, characterized in that the poppet compresses the spring (9) to disengage 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);
a sealing configuration characterized in that the spring (9) is decompressed relative to the open configuration, causing the poppet (7) to engage the valve seat (7-3) and form an airtight seal sealing the closed port opening (6-1);
The cap assembly of claim 1, wherein the opening arrangement is actuated by a force (7-2) applied to the portion (7-1) of the poppet. The cap assembly of claim 16, wherein the poppet (7) is provided with a wedge-shaped stopper (8) constructed to limit movement of the poppet (7). The electrolyte injection port (6)
A ball (11), a compression spring (12) connected to the ball (11), and a valve seat (11-1)
The electrolyte injection port (6) is
an opening configuration, characterized in that the ball (11) compresses the compression spring (12) to disengage 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);
a sealing configuration, characterized in that the compression spring (12) is decompressed relative to the open configuration, causing the ball (11) to engage with the valve seat (11-1) and form an airtight seal that seals the closed port opening (6-1);
2. The cap assembly of claim 1, wherein the opening mechanism is actuated by an injection pressure (11-2) acting on the ball (11) from the outer surface (2-1) that is greater than at least a cell can pressure (11-3) acting on the ball (11) from the inner surface (2-2). The cap assembly of claim 18, further comprising a retainer (13) constructed to limit movement of the ball (11). The electrolyte injection port (6)
Cone plug (15) and rubber valve seat (16)
The electrolyte injection port (6) is
an opening 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);
a sealing structure in which the conical plug (15) fits with the rubber valve seat (16) to form an airtight seal that seals the closed port opening (6-1);
2. The cap assembly of claim 1, wherein the opening configuration is actuated by an injection pressure (15-1) acting on the conical plug (16) from the outer surface (2-1) that is greater than at least a cell can pressure (15-2) acting on the conical plug (16) from the inner surface (2-2). The electrolyte injection port (6)
A rubber plug (21), a spring tab (20) in contact with the rubber plug (21), and a valve seat (21-1).
The electrolyte injection port (6) is
an opening configuration, characterized in that the rubber plug (21) spreads the spring tabs (20) and removes the rubber plug from the valve seat (21-1) to form the port opening (6-1) between the outer surface (2-1) and the inner surface (2-2);
a sealing structure in which the rubber plug (21) fits into the valve seat (21-1) to form an airtight seal that seals the closed port opening (6-1);
2. The cap assembly of claim 1, wherein the opening mechanism is actuated by an injection pressure (21-2) acting on the rubber plug (21) from the outer surface (2-1) that is greater than at least a cell can pressure (21-3) acting on the rubber plug (21) from the inner surface (2-2). A cap assembly (1-5),
An outer surface (2-10), an inner surface (2-2), and an outer periphery (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 (24) constructed to form a vent opening (24-1) from said inner surface (2-2) to said outer surface (2-1) when a vent pressure differential is established between an outer surface pressure and an inner surface pressure;
and an electrical insulator (4, 3),
the vent hole (24) is (a) concentric with the electrolyte injection port (6) and (b) disposed closer to the outer circumferential edge (2-3) than the electrolyte injection port (6);
the electrical insulator (4, 3) is constructed to electrically insulate the vent (24) from the electrolyte injection port (6);
A cap assembly (1-5);
a cell can housing (1) containing a pressurized electrolyte;
An electrochemical energy storage device, wherein the cap assembly (1-5) and the cell can housing (1) form a hermetic seal that prevents leakage of the electrolyte during normal operating conditions. The electrochemical energy storage device of claim 22, wherein the electrolyte comprises a salt and a solvent, the solvent being a liquefied gas having a vapor pressure exceeding atmospheric pressure of 100 kPa at a temperature of 293.15 K. 24. The electrochemical energy storage device of 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, heptane, octene, isomers thereof, saturated halogenated hydrocarbons, unsaturated halogenated hydrocarbons, and isomers of halogenated hydrocarbons. The electrochemical energy storage device of claim 24, wherein the electrochemical energy storage device is a battery or a capacitor.