Following Apple, Meta AR/VR patent hints at exploring high energy density batteries

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Meta同样在积极探索高能量密度电池

(XR Navigation Network November 22, 2023) It was reported earlier thatapple正在研发高能量密度新电池，并有望用于AR/VR提高续航。实际上，Meta同样在积极探索高能量密度电池。名为“High capacity curved battery cells”和“Process for manufacturing high capacity curved battery cells”的Meta专利申请就介绍了一种相关的曲面电池。

Specifically, the invention describes the manufacture of high-capacity curved battery cells and methods for manufacturing such high-capacity curved battery cells.

For curved batteries, multiple curved battery cells can be incorporated into curved multi-battery packs to achieve higher capacity. In this case, the radii of curvature of the cells to be stacked can be closely matched, allowing the curvatures of multiple curved cells to complement each other. Since conventional curved cells have considerable manufacturing tolerances, achieving the required radius match can be very difficult.

In addition, as the curved battery ages, various mechanical changes will occur in the curved battery. Such mechanical changes may include swelling and/or flattening of curved cells. In the case of multi-cell curved batteries, mechanical changes in multiple cells may affect the interface between adjacent curved cells, which if not taken into account may lead to loss of mechanical integrity and failure of the curved multi-cell battery pack.

Additionally, existing methods of manufacturing curved batteries involve pressing the electrodes of the curved battery together to form an electrode stack with the desired curvature. This pressing process is difficult to control and can damage curved cells if applied to multiple electrode stacks.

Conventional curved batteries are manufactured by forming a conventional electrode stack, which is then machined into a mold to give the curved electrode stack the desired curvature. However, a series of problems limit the thickness and length of electrode stacks processed into curved electrode stacks in this way.

The invention described by Meta aims to alleviate the above problems, and the team hopes to use multiple thinner curved electrode stacks to form higher-capacity curved batteries.

In one embodiment, a method of manufacturing a curved multi-cell battery pack includes forming a first curved battery cell having a first curved surface and a second curved battery cell having a complementary first curved surface. The first curved battery unit and the second curved battery unit may be installed in the battery pack housing. The battery housing may have a third curvature that complements the first curvature and/or the second curvature.

The first curved battery core and/or the second curved battery core may be attached to the curved surface of the battery pack housing through the first adhesive layer. The first curved battery core may be adhered to the second curved battery core through the second adhesive layer. The adhesion between adjacent curved cells can solve the tolerance problem of adjacent curved cells.

Therefore, the second adhesion layer may be thicker than the first adhesion layer.

Adhesion between the curved battery cells and the curved surface of the battery pack casing can be configured to maintain the curved shape of the battery pack casing. In this case, the first glue layer can be stronger and rigid.

The first adhesive layer may have a first thickness, and the second adhesive layer may have a second thickness that is thicker than the first thickness. In one example, the first adhesive layer and the second adhesive layer can be made of the same material. The first adhesive and/or the second adhesive may include double-sided pressure sensitive tape, spray adhesive, brush adhesive, etc. The first adhesive layer may include a first double-sided adhesive film tape having a first thickness, and the second adhesive layer may include a second double-sided adhesive foam tape having a second thickness thicker than the first thickness.

In one embodiment, a gap may be formed in the battery pack casing, or a gap may be formed between the curved surface of the first curved battery unit and the curved surface of the second curved battery unit, or a gap may be formed between the curved surface of the battery pack casing and the first curved surface. A gap may be formed between the curved surfaces of the battery cells or the curved surfaces of the second curved battery cells.

The voids can be filled with air or foam. As the curved battery cells cycle and age, the curved battery cells expand, and the gap formed in the battery pack housing accommodates the expansion of the first curved battery cell and/or the second curved battery cell. In one example, the thickness of the gap may be at least 10% of the total thickness of the first curved battery cell and the second curved battery cell.

In one embodiment, the first curved battery cell may have a different arc length than the second curved battery cell. The different arc lengths illustrate the tolerances that exist in curved cells. Therefore, the adhesion between the curved surface of the first curved battery cell and the curved surface of the second curved battery cell, or the adhesion between the curved surface of the battery pack case and the curved surface of the curved battery cell can be maintained.

In one embodiment, the first curved battery cell may have a different thickness than the second curved battery cell. The different thicknesses could account for the tolerance in the radius of curvature of curved cells. Additionally, battery capacity may be based at least in part on the arc length and thickness of the curved battery.

In one embodiment, the first curved battery cell may be manufactured by forming a first electrode stack and a second electrode stack. The first electrode stack includes a first cathode layer stacked on a first anode layer, and a first separator layer stacked therebetween. The second electrode stack includes a second cathode layer stacked on the second anode layer, and a second separator layer stacked therebetween.

The first electrode stack and the second electrode stack can be processed separately, so that the first electrode stack is pressed into the first curved electrode stack, and the second electrode stack is pressed into the second curved electrode stack. Both the first curved electrode stack and the second curved electrode stack may have a first curved surface. The first curved electrode stack may be connected to the second electrode stack and sealed in the first curved battery casing.

The second curved battery may be manufactured in a similar manner to the first curved battery. The second curved battery cell may be manufactured by forming a third electrode stack and a fourth electrode stack. The third electrode stack includes a third cathode layer stacked on the third anode layer, and a third separator layer stacked therebetween. The fourth electrode stack includes a fourth cathode layer stacked on the fourth anode layer, and a fourth separator layer stacked therebetween.

The third electrode stack and the fourth electrode stack can be processed separately, so that the third electrode stack is pressed into the third curved electrode stack, and the fourth electrode stack is pressed into the fourth curved electrode stack. Both the third curved surface electrode stack and the fourth curved surface electrode stack may have a second curved surface. The third curved electrode stack may be connected to the fourth electrode stack and sealed in the second curved battery casing.

The first, second, third, and fourth conductive battery cards may be electrically coupled to the first, second, third, and fourth electrode stacks, respectively. The conductive sheets may be electrically coupled to the electrode stacks before the electrode stacks are machined to their respective curvatures.

The first conductive unit card and the second conductive unit card may be electrically coupled in a parallel connection. Similarly, the third conductive unit card and the fourth conductive unit card may be electrically coupled in a parallel connection.

In one embodiment, the first electrode stack and the second electrode stack can be processed by pressing the first electrode stack and the second electrode stack into a mold having a first curvature to form a first curved electrode stack and a second electrode stack. Curved electrode stack.

In addition, by pressing the third electrode stack and the fourth electrode stack into the mold having the second curvature, the third electrode stack and the fourth electrode stack can be processed into the third curved surface electrode stack and the fourth curved surface electrode stack.

Before connecting the first curved surface electrode stack and the second curved surface electrode stack together, the first electrode stack and the second curved surface electrode stack may be processed separately, and before connecting the third curved surface electrode stack and the fourth curved surface electrode stack together, The third electrode stack and the fourth electrode stack can be processed separately.

The first curved electrode stack may be adhered to the second curved electrode stack via a first adhesive, and the third curved electrode stack may be adhered to the fourth curved electrode stack via a second adhesive. Each curved battery casing contains at least two thin electrode stacks connected together.

Meta notes that this allows for the creation of thicker, higher-capacity batteries than previously possible using traditional battery manufacturing techniques.

FIG. 1 shows a curved multi-battery pack 100 that includes a first curved battery 102 and a second curved battery 104 located in a curved battery housing 106 . The first curved battery 102, the second curved battery 104 and the curved battery housing 106 have curvatures that complement each other. Complementary curvatures allow close contact to be maintained at the interface between adjacent surfaces.

The first curved battery 102 may have an arc length that is shorter, longer, or the same as that of the second curved battery 104 . The different arc lengths may be based at least in part on the radius of curvature of the curved multi-cell pack 100 and/or the size, shape, and configuration of the curved battery housing 106 . For example, in embodiments with different arc lengths, the different arc lengths may utilize the shape of the curved battery housing 106 .

In the example shown, the second curved battery 104 may be longer than the first curved battery 102 because it is disposed radially outside the first curved battery 102 . That is, for a curved battery housing with a given radius of curvature, the radially inward curved battery may have a shorter arc length than one or more curved batteries arranged radially outward.

This arrangement maximizes the amount of electrode material, making it suitable for curved battery housing 106 .

In one embodiment, the first curved battery 102 and the second curved battery 104 may have the same or different thicknesses. The different thicknesses could account for the tolerance in the radius of curvature of curved cells. In addition, the first curved battery 102 may have the same or different width as the second curved battery 104 .

For example, the width of the second curved battery unit 104 may be wider or narrower than the first curved battery unit 102 . Energy storage capacity may be determined, at least in part, by the arc length, width, and thickness of the curved battery cells. The arc length, width, and thickness of the curved battery cell may be selected to maximize the storage capacity of the battery cell given the limited volume and form factor of the battery pack housing and/or the electronic device that will house the battery cell.

The first adhesive 108 may adhere the first curved battery cell 102 to the curved surface of the curved battery housing 106 . The second adhesive 110 can adhere the opposite curved surfaces of the first curved battery 102 and the second curved battery 104 together. The first adhesive 108 and the second adhesive 110 may be made of the same material, and the second adhesive 110 may be thicker than the first adhesive 108 .

The second adhesive 110 can take into account manufacturing tolerances and variations between battery cells, and can maintain adhesion between the first curved battery unit 102 and the second curved battery unit. The first adhesive 108 may be harder than the second adhesive 110 to maintain the curvature of the curved battery housing 106 .

Figure 2 shows a curved multi-battery pack 200, which includes a first curved battery cell 202 and a second curved battery cell 204. The battery cell 204 is located in the curved battery case 206 . The first curved battery cell 202, the second curved battery cell 204, and the curved battery housing 206 have curvatures that complement each other.

The complementary curvatures allow the interface between the bottom surface of the curved battery housing 206 and the first curved battery cell 202 and the interface between the top surface of the curved battery housing 206 and the second curved battery cell 204 to maintain close contact.

The first curved battery cell 202 may have an arc length that is the same as, longer than, or shorter than the second curved battery cell 204 . In addition, the first curved battery unit 202 may have the same or different width as the second curved battery unit 204 . For example, the width of the second curved battery cell 204 may be wider or narrower than the first curved battery cell 202 . The different arc lengths and/or widths may be based at least in part on the radius of curvature of the curved multi-cell pack 200 and/or the size, shape, and configuration of the curved battery housing 206 .

For example, in embodiments with different arc lengths and/or widths, the different arc lengths and/or widths may utilize the shape of the curved battery housing 206 . For example, the second curved battery cell 204 may be longer than the first curved battery cell 202 due to being arranged radially outward from the first curved battery cell 202 . That is, for a curved battery housing having a radius of curvature, the battery cells of the radially inner curved surface may have a shorter arc length than the battery cells of one or more curved surfaces arranged radially outward.

This arrangement maximizes the amount of electrode material, making it suitable for curved battery housing 106 .

In one embodiment, the first curved battery cell 202 and the second curved battery cell 204 may have the same or different thicknesses. The different thicknesses could account for the tolerance in the radius of curvature of curved cells. As discussed above, energy storage capacity may be determined at least in part by the arc length, width, and thickness of the curved battery cells. The arc length, width, and thickness of the curved battery cell may be selected to maximize the storage capacity of the battery cell given the limited volume and form factor of the battery pack housing and/or the electronic device that will house the battery cell.

The first adhesive 208 may adhere the first curved battery cell 202 to the first radially inwardly curved surface of the curved battery housing 206 . The second adhesive 210 may adhere the second curved battery cell 204 to the second radially outward curved surface of the curved battery housing 206 .

Figure 3 illustrates an example method 300 of manufacturing a curved battery cell. Curved battery cells may include two or more electrode stacks. In the example, the first electrode stack 302 has a first length L1 and the second electrode stack 304 has a second stack L2.

During a first operation (Operation A), each electrode stack may be fabricated by forming a stack including one or more anode layers and one or more cathode layers, separated by respective separator layers. Different electrode stacks can have different lengths. For example, the length L1 of the first electrode stack 302 may be longer than the length L2 of the second electrode stack 304 so that their respective ends are substantially aligned after they are bent.

During the second operation (operation B), the electrode stacks are treated individually to impart curvature. The curvature given to the individual electrode stacks may be the same or complementary. The electrode stack can be machined by pressing the electrode stack into a mold with the desired curvature. The electrode stack can be pressed into the mold at a temperature below the melting point of the separator layer arranged between the anode layer and the cathode layer. For example, the electrode stack can be processed by hot pressing the electrode stack at a temperature between about 50°C and about 130°C.

In a third operation (operation C), individual curved electrode stacks can be combined or coupled together so that the curvatures complement each other. For example, the concave inner radius of curvature of the first electrode stack 302 may be substantially the same as the convex outer radius of curvature of the second electrode stack 304 such that they are consistent with the concave inner radius of curvature of the first electrode stack 302 relative to the convex outer radius of the second electrode stack 304 . Curvature radii are nested together.

In one embodiment, an adhesive may be provided between individual electrode stacks. The individual electrode stacks may be pressed together under the same or different conditions used in operation B to impart curvature to the individual electrode stacks. In one embodiment, the force used to press the electrode stacks together in operation C may be less than the force used to apply curvature to the individual electrode stacks in operation B.

In one embodiment, the electrode stacks can be of different lengths. For example, first electrode stack 302 may have a first length that is longer than a second length of second electrode stack 304 . Therefore, when the first electrode stack 302 is coupled to the second electrode stack 304 in operation C, both ends of the first electrode stack 302 and the second electrode stack 304 are substantially aligned.

That is, since in this embodiment, the first electrode stack 302 is arranged radially outside the second electrode stack 304, the arc length of the first electrode stack 302 may be greater than the arc length of the second electrode stack 304. Specifically, as shown in operation 2 of FIG. 3 , the first arc length AL1 of the inner radius of the first electrode stack 302 is substantially equal to the second arc length AL2 of the outer radius of the second electrode stack 304 .

Accordingly, the length L1 of the first electrode stack 302 relative to the length L2 of the second electrode stack 304 may be based at least in part on the radius of curvature to be imparted to the respective electrode stack.

During a fourth operation (operation D), the combined electrode stack may then be inserted and enclosed in a curved battery housing 308 . Before sealing the battery housing 308, the electrolytic solution may be included in the battery housing. Conductive cell sheets 306 may be combined to provide an outer conductive sheet 310 .

Figure 5 shows a curved multi-battery pack 500, including a first curved battery unit 502 and a second curved battery unit 504. The first curved battery cell 502 and the second curved battery cell 504 are complementary to the curved surface of the curved battery housing 506 . The complementary curvatures allow close contact to be maintained at the interface between adjacent curved surfaces of first curved battery cell 502 , second curved battery cell 504 , and curved battery housing 506 .

The first adhesive 508 can adhere the first curved battery cell 502 to the curved surface of the curved battery housing 506 . The second adhesive 510 can adhere the second curved battery cell 504 to the curved surface of the curved battery housing 506 .

As the first curved battery 502 and the second curved battery 504 age and cycle, the batteries expand. Therefore, the curved battery housing 506 may include a gap 512 between the first curved battery housing 502 and the second curved battery housing 504 . The gap 512 may be filled with air, thereby creating an air gap.

Figure 6 illustrates an exemplary process 600 for manufacturing a curved battery cell.

Operation 602 may include forming two separate electrode stacks of slightly different sizes. Slightly different dimensions may be thickness, width, and/or length of individual electrode stacks. The individual electrode stacks can have different lengths from each other. The different lengths account for the tolerances present in the electrode stack when the electrode stack forms a curved electrode stack. Therefore, the adhesion between the curved surfaces of the curved electrode stack can be maintained.

Operation 604 includes connecting conductive sheets to each electrode stack. The conductive sheets can be electrically coupled to the individual electrode stacks before the electrode stacks are machined to form their respective curvatures.

Operation 606 includes processing the electrode stack to form a curved electrode stack. Electrode stacks can be individually machined to form complementary curvatures. In one embodiment, electrode stacks may be machined by pressing a single electrode stack into a mold with the desired curvature.

Operation 608 includes pressing the curved electrode stack together. Curved electrode stacks can be pressed together to form a single stack so that the curvatures complement each other. Alternatively, individual curved electrode stacks may be adhered to each other by one or more adhesive layers disposed between adjacent electrode stacks.

Operation 610 includes placing the depressed curved electrode stack in the curved package. The combined curved electrode stack allows for the fabrication of thicker batteries with higher capacities.

Operations 612 and 614 include the back-end process of converting the electrode stack into a battery. Operation 612 includes filling the curved package with electrolytic material. Operation 614 includes sealing the battery housing and applying one or more additional back-end processes.

Related patents:Meta Patent | High capacity curved battery cells
Related patents:Meta Patent | Process for manufacturing high capacity curved battery cells

The Meta patent applications titled "High capacity curved battery cells" and "Process for manufacturing high capacity curved battery cells" were originally submitted in April 2022 and were recently published by the US Patent and Trademark Office.