Molded electrode film and method thereof

Abstract

The present invention provides electrode films for energy storage devices, a method for forming the same, and products manufactured therefrom. [Solution] The electrode film 200 having a molded edge 240 can help improve the core circularity of the electrode assembly, thereby minimizing changes in the design and manufacture of the electrode assembly and improving the structural stability of the energy storage device.

Description

[Technical Field]

[0001] This disclosure relates to electrode films for energy storage devices and methods for producing them. In particular, this disclosure relates to the method for forming molded electrode films. [Background technology]

[0002] A typical energy storage device comprises an electrode film. The electrode film can be used to form an electrode assembly using a winding process. Many current electrode assemblies use a jelly roll design in which the electrodes and separators are wound together and have cathode and anode tabs for connecting to the positive and negative terminals of the electrode assembly. Generally, wound electrode films contain defects that affect the circularity of the electrode assembly (e.g., natural kinks, weak points, stress points, and / or electrode buckling zones), which can affect the lifespan of the energy storage device.

[0003] Therefore, improving the circularity of mass-produced energy storage devices may be advantageous. [Overview of the Initiative]

[0004] For the purpose of summarizing the advantages achieved beyond the present invention and the prior art, specific purposes and advantages of the present invention are described herein. Not all such purposes or advantages can be achieved in any particular embodiment of the present invention. Therefore, for example, those skilled in the art will recognize that the present invention can be embodied or practiced in a manner that achieves or optimizes one advantage or set of advantages taught herein, without necessarily achieving other purposes or advantages that may be taught or suggested herein.

[0005] In one embodiment, an energy storage device is described. The energy storage device comprises an electrode assembly and an electrolyte disposed within a housing, the electrode assembly comprising a first electrode, a second electrode, and a separator located between the first electrode and the second electrode, the first electrode comprising a molded electrode film and a current collector, the molded electrode film being disposed on the current collector, the molded electrode film comprising an active material, and a length, length end and width, where the length is greater than the width, and a molded edge located at the length end, the molded edge comprising a taper angle and a taper distance.

[0006] In another embodiment, a molded electrode film is described. The molded electrode film comprises an active material, a length, a length end, and a width, wherein the length is greater than the width, and a molded edge located at the length end, wherein the molded edge includes a taper angle and a taper distance.

[0007] In some embodiments, the molded electrode film further includes a second molded edge located at a second length end. In some embodiments, the molded edge is selected from the group consisting of a square edge, a double square edge, a V-shaped edge, a double V-shaped edge, a rounded edge, a double rounded edge, the opposite, the reverse, and combinations thereof. In some embodiments, the taper angle is approximately 10° to 45°. In some embodiments, the taper distance is approximately 25 mm or less.

[0008] In another embodiment, a molded electrode is described. The molded electrode comprises a molded electrode film and a current collector, the molded electrode film being disposed on the current collector.

[0009] In another embodiment, an electrode assembly is described. The electrode assembly includes a molded electrode, a second electrode, and a separator positioned between the molded electrode and the second electrode.

[0010] In some embodiments, the electrode assembly is a wound electrode assembly. In some embodiments, the second electrode includes a second molded edge. In some embodiments, the electrode assembly is selected from the group consisting of cylindrical energy storage devices and helically wound prismatic energy storage devices. In some embodiments, the electrode assembly includes a normalized circularity value of at least about 0.8. In some embodiments, the electrode assembly includes a normalized circularity value of at least about 0.9.

[0011] In another embodiment, an energy storage device is described. The energy storage device includes an electrode assembly, an electrolyte, and a housing in which the electrode assembly and the electrolyte are disposed.

[0012] Another embodiment describes a method for forming a molded electrode film. This method includes providing an electrode film having a length, length end, and width, wherein the length is greater than the width, and forming the length end to form a molded electrode film including a molded edge.

[0013] In some embodiments, the method further includes forming a molded electrode, which includes a molded electrode film placed on a current collector. In some embodiments, the current collector is a molded edge current collector. In some embodiments, an adhesive layer is placed between the molded electrode film and the current collector. In some embodiments, the adhesive layer is a molded edge adhesive layer. In some embodiments, the method further includes placing the electrode film on the current collector. In some embodiments, forming the length end includes removing the scrap electrode film from the current collector. In some embodiments, the method further includes placing the molded electrode film on the current collector. [Brief explanation of the drawing]

[0014] [Figure 1A] This is a schematic diagram of an unformed electrode film.

[0015] [Figure 1B]It is a schematic diagram of an electrode assembly showing a cross-section of an unformed electrode film wound around a jelly roll.

[0016] [Figure 2A] It is a schematic diagram of a formed electrode film including corner edges according to some embodiments.

[0017] [Figure 2B] It is a schematic diagram of an electrode assembly showing a cross-section of a formed electrode film wound around a jelly roll according to some embodiments.

[0018] [Figure 3A] It is a schematic diagram of a formed electrode film including a chevron edge according to some embodiments.

[0019] [Figure 3B] It is a schematic diagram of a formed electrode film including a rounded edge according to some embodiments.

[0020] [Figure 3C] It is a schematic diagram of a formed electrode film including a double chevron edge according to some embodiments.

[0021] [Figure 4A] It is a flowchart of a method for forming a formed electrode film according to some embodiments.

[0022] [Figure 4B] It is a flowchart of a method for forming a formed electrode including a formed electrode film according to some embodiments.

[0023] [Figure 4C] It is another flowchart of a method for forming a formed electrode including a formed electrode film according to some embodiments.

[0024] [Figure 5A] It is a schematic diagram of a formed electrode including a formed electrode film and a current collector according to some embodiments.

[0025] [Figure 5B] This is a schematic diagram of a molded electrode including a molded electrode film and a molded edge current collector according to several embodiments.

[0026] [Figure 5C] This is a schematic diagram of a molded electrode including a molded electrode film, an adhesive layer, and a current collector, according to several embodiments.

[0027] [Figure 5D] This is a schematic diagram of a molded electrode including a molded electrode film, a molded edge adhesive layer, and a current collector, according to several embodiments.

[0028] [Figure 5E] This is a schematic diagram of a double-sided molded electrode including a molded electrode film according to several embodiments.

[0029] However, it should be clearly understood that the examples and drawings are for illustrative purposes only and do not necessarily limit the scope of the present invention. [Modes for carrying out the invention]

[0030] While certain preferred embodiments and examples are disclosed below, the subject matter of the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and / or uses, as well as their modifications and equivalents. Therefore, the appended claims are not limited by any of the specific embodiments described below. For example, in any method or process disclosed herein, the operation or behavior of the method or process may be performed in any suitable order, and is not necessarily limited to any specific disclosed order. For this reason, various operations can be described as a number of separate operations in a manner that may be helpful in understanding a particular embodiment. However, the order of description should not be construed as meaning that these operations are order-dependent. Furthermore, the structures, systems, and / or devices described herein may be embodied as integrated components or as separate components. For the purpose of comparing various embodiments, specific aspects and advantages of these embodiments are described. Not all such aspects or advantages are necessarily achieved by any particular embodiment. Therefore, for example, various embodiments may be performed to achieve or optimize one advantage or group of advantages taught herein, without necessarily achieving other aspects or advantages that may similarly be taught or suggested herein.

[0031] This paper describes electrode films having molded edges (i.e., non-linear edges) and methods thereof. By utilizing molded electrode films in wound electrode assemblies of energy storage devices, circularity defects in the wound assembly (e.g., kinks, weak points, stress points, and / or electrode buckling zones) can be distributed to different circumferential locations of the electrode assembly, resulting in improved winding circularity of the electrode assembly core. Thus, molded electrodes that provide improved circularity help prevent electrode buckling in the electrode assembly and / or during the cycle after winding, thereby improving the lifespan of the energy storage device.

[0032] Molded electrode film Electrode films can be manufactured or formed using various unformed and formed edges. Unformed electrode films (e.g., baseline, straight edge, rectangular shape) may include a rectangular edge. For example, Figure 1A is a schematic diagram of an unformed electrode film 100. As shown in Figure 1A, the unformed electrode film 100 includes a length 110, a width 120, a length end 125, and an unformed edge 130 on the length end 125. The unformed electrode film 100 is shown as a rectangle, with all intersecting sides forming right angles.

[0033] Figure 1B is a schematic diagram of an energy storage device 150 including a wound unformed electrode film and horizontal cross-sections 180a to 180d of the wound unformed electrode film. Since the wound electrode film is unformed, the horizontal cross-sections 180a to 180d each show the corresponding leading edges 185a to 185d (i.e., terminal edges) of the unformed edges that are aligned perpendicularly to each other.

[0034] Figure 2A is a schematic diagram of a molded electrode film 200 including a corner edge according to several embodiments. As shown in Figure 2A, the molded electrode film 200 includes a length 210, a width 220, a length end 235, a first corner 225 on the length end 235, a second corner 230 on the length end 235, and a molded edge 240 on the length end 235. The molded edge 240 includes a taper angle 242, measured as the angle the molded edge 240 makes with the first corner 225, and a taper distance 247, measured as the horizontal length distance between the first corner 225 and the second corner 230. The molded electrode film 200 also includes a second molded edge 245 that is opposite, inverted, or reversed in shape to the molded edge 240. The molded edge 240 is an angular edge, and the molded edge 240 forms a single straight line with a non-perpendicular (i.e., not 90°) taper angle 242 between the molded edge 240 and the baseline edge 241.

[0035] Figure 2B is a schematic diagram of an energy storage device 250 including a wound-molded electrode film and horizontal cross-sections 280a to 280d of the wound-molded electrode film. Once the wound-molded electrode film is formed, the horizontal cross-sections 280a to 280d each show the corresponding inner leading edges 285a to 285d (i.e., terminal edges) of the formed edges, which are not aligned perpendicularly to each other but instead are positioned at various circumferential locations on the core of the energy storage device. The wound-molded electrode film is shown including a second formed edge, and therefore the horizontal cross-sections 280a to 280d also show outer leading edges that are not aligned perpendicularly to each other but instead are positioned at various circumferential locations on the core of the energy storage device.

[0036] Figure 2A shows an electrode film 200 having a square edge, but in some embodiments, molded electrode films having other shapes for the molded edge are possible. For example, Figure 3A is a schematic diagram of a molded electrode film 300 including a V-shaped edge as the shape of a molded edge 310 and an inverted or opposite V-shaped edge as the shape of a second molded edge 320. The molded edge 310 is indicated by a molding angle 315 and a taper distance 317 with respect to the V-shaped edge shape. It is understood that the V-shaped edge shape includes an additional molding angle, and the inverted or opposite V-shaped edge shape includes two additional molding angles and an additional taper distance.

[0037] Figure 3B is a schematic diagram of a molded electrode film 330, including a rounded edge as the shape of the molded edge 335, according to several embodiments. As shown in Figure 3B, the molded edge 335 is indicated by an angular angle 338 for the rounded edge shape and a taper distance 339. The molded electrode film 330 also includes an unmolded edge 340 on the opposite side of the molded edge 335. Although only the angular angle 338 is shown, it is understood that the rounded edge shape includes an infinite number of taper angles along its arc shape.

[0038] Figure 3C is a schematic diagram of a molded electrode film 350, including a double chevron edge as the shape of the molded edge 360, according to several embodiments. As shown in Figure 3C, the molded edge 360 ​​is indicated by a first taper angle 362 and a taper distance 364. The molded electrode film 350 also includes a second molded edge 370 having an inverted or opposite double chevron edge. It is understood that the double chevron edge shape includes an additional molding angle, and the inverted or opposite double chevron edge shape includes an additional molding angle and an additional taper distance.

[0039] In some embodiments, the length of the electrode film is in the range of 1m, 1.5m, 2m, 2.5m, 3.0m, 3.5m, 4m, 4.5m, 5m, 5.5m, 6m, 6.5m, 7m, or any value in between, or is approximately one of these values, at least one of these values, or at least approximately one of these values. In some embodiments, the length is greater than the width.

[0040] In some embodiments, the width of the electrode film is 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, 85 mm, 90 mm, 95 mm, 100 mm, 105 mm, 110 mm, 115 mm, 120 mm, 125 mm, 130 mm, 135 mm, 140 mm, 145 mm, 150 mm, or any range of values ​​between them, or is approximately one of these values, at least one of these values, or at least approximately one of these values.

[0041] In some embodiments, the taper distance of the electrode film is 0.1 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, or any range of values ​​between these, approximately these values, at least these values, or at least approximately these values.

[0042] In some embodiments, the molded edge is selected from the group consisting of a square edge, a double square edge, a V-shaped edge, a double V-shaped edge, a rounded edge, a double rounded edge, the opposite thereof, the reverse thereof, and combinations thereof. In some embodiments, the molded electrode film includes an unmolded edge.

[0043] In some embodiments, the molded edge is 0.1°, 0.2°, 0.3°, 0.4°, 0.5°, 0.6°, 0.7°, 0.8°, 0.9°, 1°, 1.1°, 1.2°, 1.3°, 1.4°, 1.5°, 1.6°, 1.7°, 1.8°, 1.9°, 2°, 2.1°, 2.2°, 2.3°, 2.4°, 2.5°, 2.6°, 2.7°, 2.8°, 2.9°, 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, 11°, 12°, 13°, 14°, 15° The tapered angle includes 10° to 45°, 16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, 25°, 26°, 27°, 28°, 29°, 30°, 31°, 32°, 33°, 34°, 35°, 36°, 37°, 38°, 39°, 40°, 41°, 42°, 43°, 44°, or 45°, or any range of values ​​between them, approximately these values, at least these values, or at least approximately these values. In some embodiments, the molded edge includes a tapered angle of 10° to 45°, approximately these values, at least these values, or at least approximately these values. In some embodiments, the molded edge includes a tapered angle of 10° to 15°, approximately these values, at least these values, or at least approximately these values. In some embodiments, the molded electrode film may include two or more taper angles. In some embodiments, the molded electrode film may include an infinite number of angles (for example, in the case of a rounded edge electrode film).

[0044] In some embodiments, the electrode film includes a thickness of 1000 μm, 900 μm, 800 μm, 700 μm, 600 μm, 500 μm, 400 μm, 300 μm, 250 μm, 200 μm, 150 μm, 100 μm, 90 μm, 80 μm, 70 μm, 60 μm, 50 μm, 40 μm, 30 μm, 20 μm, 15 μm, 10 μm, or any range between these values, approximately these values, at least these values, or at least approximately these values.

[0045] Method for forming molded electrode films Figure 4A is a flowchart showing a method for forming a molded electrode film according to several embodiments. As shown in Figure 4A, the forming process 400 includes the step 410 of providing an electrode film and the step 420 of forming the length end of the electrode film to form a molded electrode film including a molded edge. Figure 4B is a flowchart showing a method for forming a molded electrode including a molded electrode film according to several embodiments. As shown in Figure 4B, the forming process 430 includes the step 435 of providing an electrode film, the step 440 of forming the length end of the electrode film to form a molded electrode film including a molded edge, and the step 450 of placing the molded electrode on a current collector to form an electrode.

[0046] In some embodiments, the length end may be formed by cutting the electrode film, current collector and / or electrode (e.g., manual cutting, mechanical cutting, punching). In some embodiments, the length end of the electrode film (e.g., formed by peeling) may be formed by removing scrap electrode film from the current collector. In some embodiments, an adhesive layer may be placed on the current collector, and the length end may be formed by removing scrap electrode film from the current collector.

[0047] Figure 4C is another flowchart illustrating a method for forming a molded electrode including a molded electrode film according to several embodiments. As shown in Figure 4C, the forming process 460 includes the steps of providing the electrode film 465, placing the electrode film on a current collector 480, and forming the length ends of the electrode film by removing (e.g., peeling) scrap electrode film from the current collector.

[0048] In some embodiments, the method for forming the electrodes may include forming a molded edge current collector and / or a molded edge current collector. In some embodiments, the method for forming the electrodes may include placing an adhesive layer (e.g., a carbon coating layer) on and / or between the electrode film and the current collector. In some embodiments, the carbon coating layer may be processed to form a molded edge and / or a molded edge carbon coating layer.

[0049] Molded electrodes and methods The electrodes and energy storage devices may include molded electrode films. For example, Figure 5A is a schematic diagram of the layers of a molded electrode 500A, including a molded electrode film 505A placed on an unmolded current collector 530A. Figure 5B is a schematic diagram of the layers of a molded electrode 500B, including a molded electrode film 505B placed on a molded edge current collector 530B. Figure 5C is a schematic diagram of the layers of a molded electrode 500C, including a molded electrode film 505C placed on an adhesive layer 520C placed on an unmolded current collector 530C. Figure 5D is a schematic diagram of the layers of a molded electrode 500D, including a molded electrode film 505D placed on a molded edge adhesive layer 520D placed on an unmolded current collector 530D. Figure 5E is a schematic diagram of the layers of a double-sided molded electrode 500E, including molded electrode films 505E, 550E, adhesive layer 520E, molded edge current collector 530E, and molded edge adhesive layer 540E.

[0050] In some embodiments, different combinations of molded electrode film and unmolded electrode film, current collector, and adhesive layer within the energy storage device can provide improved control of normalized circularity, ease of manufacture, and prevention of buckling of the electrode assembly during cycling or use. In some embodiments, the molded electrode is an electrode comprising a molded electrode film, which optionally includes a molded edge current collector and / or a molded edge adhesive layer.

[0051] In some embodiments, the electrode and / or current collector includes an adhesive layer. In some embodiments, a molded electrode film is placed on the adhesive layer and bonded to the adhesive layer. In some embodiments, the adhesive layer includes a carbon coating layer. In some embodiments, the carbon coating layer includes a conductive carbon coating or layer. In some embodiments, the molded electrode and / or current collector includes an electrode foil and an insulator (e.g., a carbon coating layer) placed over the entire, substantially the entire, or part of the current collector. In some embodiments, the current collector includes a single adhesive layer. In some embodiments, the adhesive layer is a patterned adhesive layer. In some embodiments, the adhesive layer includes a plurality of adhesive elements separated from each other. In some embodiments, the adhesive layer is size-on-size with the molded electrode film placed on the adhesive layer. In some embodiments, the adhesive layer is larger than the molded electrode film placed on the adhesive layer. In some embodiments, the adhesive layer is placed on the current collector to form a coated current collector, and the molded electrode film is placed on the coated current collector to form an electrode. In some embodiments, the adhesive layer may be a molded edge adhesive layer.

[0052] In some embodiments, the electrode is a single-sided electrode. In some embodiments, the electrode is a double-sided electrode comprising two electrode films positioned on both sides of a current collector. In some embodiments, at least a portion of the electrode is a single-sided electrode and / or a double-sided electrode (for example, this portion is located at the end of the electrode). In some embodiments, the double-sided electrode comprises one or two molded electrode films of the same or different shapes. In some embodiments, the double-sided electrode comprises one or two adhesive layers of the same or different shapes. In some embodiments, the current collector may be a molded edge current collector. In some embodiments, the double-sided electrode comprises two molded electrodes. In some embodiments, two molded electrodes comprise one or more molded electrode films.

[0053] Electrode materials, electrode films, electrodes, and energy storage devices The active material (e.g., cathode active material, anode active material) can be used to prepare electrode films and / or electrodes for energy storage devices such as the molded electrode films and molded electrodes described herein. In some embodiments, the electrode includes a current collector and an electrode film.

[0054] In some embodiments, the active material is a cathode active material. In some embodiments, the cathode active material is selected from at least one of materials comprising metal oxides, metal sulfides, sulfur-carbon composites, lithium metal oxides, and sulfur. In some embodiments, the cathode active material is lithium iron phosphate (i.e., LiFePO4 or "LFP"), lithium iron manganese phosphate (e.g., LiMn 0.6 Fe 0.4 PO4 or "LMFP"), lithium nickel manganese cobalt oxide (i.e., LiNi x Mn y Co 1-x-y O2 or "NMC"), lithium nickel cobalt aluminum oxide (i.e., LiNi x Co y Al zIt is selected from O2 or "NCA", lithium manganese oxide ("LMO"), lithium nickel manganese oxide ("LNMO"), lithium cobalt oxide ("LCO"), lithium titanate ("LTO"), or a combination thereof. In some embodiments, the cathode active material comprises at least two of LFP, LMFP, NMC, NCA, LMO, LNMO, LCO, LTO, and combinations thereof. In some embodiments, the cathode active material is an iron phosphate-based active material. In some embodiments, the iron phosphate-based active material comprises LiFePO4 (i.e., "lithium iron phosphate" and "LFP") and LiMn 1-x Fe x PO4 (i.e., "lithium manganese iron phosphate" and "LMFP") (e.g., LiMn 0.6 Fe 0.4 PO4 or LiMn 0.8 Fe 0.2 PO4). In some embodiments, the iron phosphate-based active material comprises LFP. In some embodiments, the iron phosphate-based active material comprises LMFP. In some embodiments, the iron phosphate-based active material comprises LFP and / or LMFP.

[0055] In some embodiments, the active material is an anode active material. In some embodiments, the anode active material may include, for example, an insert material (such as carbon, graphite, and / or graphene), an alloying / dealloying material (such as silicon, silicon oxide, tin, and / or tin oxide), a metallic alloy or compound (such as Si-Al and / or Si-Sn), and / or a conversion material (such as manganese oxide, molybdenum oxide, nickel oxide, and / or copper oxide). The anode active material may be used alone or mixed together to form a multiphase material (such as Si-C, Sn-C, SiOx-C, SnOx-C, Si-Sn, Si-SiOx, Sn-SnOx, Si-SiOx-C, Sn-SnOx-C, Si-Sn-C, SiOx-SnOx-C, Si-SiOx-Sn, Sn-SiOx-SnOx, etc.). Anode active materials include common natural graphite, synthetic or artificial graphite, surface-modified graphite, spherical graphite, flake graphite, and blends or combinations of these types of graphite, metallic elements and their compounds, as well as metal-C composites for anodes.

[0056] In some embodiments, the electrode film mixture and / or electrode film contains an amount of active material that is approximately 70% by weight, 75% by weight, 80% by weight, 85% by weight, 86% by weight, 87% by weight, 88% by weight, 89% by weight, 90% by weight, 91% by weight, 92% by weight, 93% by weight, 94% by weight, 95% by weight, 96% by weight, 97% by weight, 98% by weight, 98.5% by weight, 99% by weight, 99.5% by weight, 99.8% by weight, or 99.9% by weight, or any range of values ​​between them, or is approximately these values, at least these values, or at least approximately these values.

[0057] In some embodiments, the electrode film mixture and / or electrode film (e.g., molded electrode film) includes a carbon material configured to reversibly insert lithium ions. In some embodiments, the lithium-inserted carbon is selected from graphitic carbon, graphite, hard carbon, soft carbon, and combinations thereof. For example, the electrode film of an electrode may include a binder material, one or more of graphitic carbon, graphite, graphene-containing carbon, hard carbon, and soft carbon, as well as a conductivity-enhancing material. In some embodiments, the electrode is mixed with lithium metal and / or lithium ions. In some embodiments, the electrode includes a total amount of carbon material that is approximately 20% by weight, 15% by weight, 10% by weight, 9% by weight, 8% by weight, 7% by weight, 6% by weight, 5% by weight, 4% by weight, 3% by weight, 2% by weight, 1% by weight, or any range of values ​​between these, or is approximately these values, or is at most these values, or is at most approximately these values.

[0058] In some embodiments, the electrode film mixture and / or electrode film includes a conductive additive. In some embodiments, the conductive additive may include a conductive carbon additive such as carbon black. In some embodiments, the conductive additive may include a conductive carbon additive. In some embodiments, the conductive carbon additive includes carbon nanotubes such as carbon black, single-walled carbon nanotubes (SWCNTs), and multi-walled carbon nanotubes (MWCNTs). In some embodiments, the electrode film contains the conductive additive in a total amount that is 10% by weight, 9% by weight, 8% by weight, 7% by weight, 6% by weight, 5% by weight, 4% by weight, 3% by weight, 2% by weight, 1% by weight, 0.5% by weight, 0.25% by weight, 0.1% by weight, or any range of values ​​between these, or is approximately these values, or is at most these values, or is at most approximately these values. In some embodiments, each of the conductive additives is in an amount that is 10% by weight, 9% by weight, 8% by weight, 7% by weight, 6% by weight, 5% by weight, 4% by weight, 3% by weight, 2% by weight, 1% by weight, 0.5% by weight, 0.25% by weight, 0.1% by weight, or any value in between, or is approximately one of these values, or is at most one of these values, or is at most one of these values. In some embodiments, the conductive additive is carbon black.

[0059] In some embodiments, the electrode film mixture and / or electrode film includes a binder. In some embodiments, the binder may include polytetrafluoroethylene (PTFE), polyolefins, polyalkylenes, polyethers, styrene-butadiene, polysiloxane copolymers and polysiloxanes, branched polyethers, polyvinyl ethers, carboxymethylcellulose (CMC), copolymers thereof, and / or combinations thereof. In some embodiments, the polyolefin may include polyethylene (PE), polypropylene (PP), polyvinylidene fluoride (PVDF), copolymers thereof, and / or combinations thereof. For example, the binder may include polyvinyl chloride, poly(phenylene oxide) (PPO), polyethylene-block-poly(ethylene glycol), poly(ethylene oxide) (PEO), poly(phenylene oxide) (PPO), polyethylene-block-poly(ethylene glycol), polydimethylsiloxane (PDMS), polydimethylsiloxane-coalkylmethylsiloxane, copolymers thereof, and / or combinations thereof. In some embodiments, the binder may include a thermoplastic material. In some embodiments, the binder comprises a fibrillable and / or fibrillable polymer. In certain embodiments, the binder comprises, essentially comprises, or comprises a single fibrillable and / or fibrillable binder such as PTFE. In some embodiments, the electrode film comprises a binder in a range of values ​​of about 1% by weight, 2% by weight, 3% by weight, 4% by weight, 5% by weight, 6% by weight, 7% by weight, 8% by weight, 9% by weight, 10% by weight, or any range of values ​​in between, or a binder with approximately these values, or a binder with up to approximately these values.

[0060] Where provided herein, “solvent-free” electrode films (e.g., molded or unmolded) are electrode films that do not contain detectable processing solvents, processing solvent residues, or processing solvent impurities. Dry electrode films, such as cathode electrode films or anode electrode films made from dry components alone, may also be solvent-free.

[0061] A “wet” electrode, a “wet process” electrode, or a slurry electrode is an electrode, or comprises an electrode film (e.g., molded or unmolded) prepared by at least one step comprising a slurry of active material(s), binder(s), and optionally additive(s), even if a subsequent drying step removes moisture from the electrode or electrode film. Thus, a wet electrode or wet electrode film comprises at least one or more processing solvents, processing solvent residues, and / or processing solvent impurities.

[0062] In some embodiments, the electrode film may be a wet-processed electrode film. In some embodiments, the electrode film is prepared by a wet or slurry-based electrode manufacturing process. In some embodiments, the electrode film of the Disclosure may be a dry-processed electrode film. In some embodiments, the electrode film is prepared by a dry electrode manufacturing process. As used herein, a dry electrode manufacturing process may refer to a process that forms a dry electrode film without the use of a solvent, or substantially without the use of a solvent. For example, the components of an active layer or electrode film, comprising a carbon material and a binder, may include, consist of, or essentially consist of dry particles. A combination of dry particles for forming an active layer or electrode film can be provided to provide a dry particle active layer mixture. In some embodiments, the active layer or electrode film may be formed from a dry particle active layer mixture such that the weight percentages of the components of the active layer or electrode film and the weight percentages of the components of the dry particle active layer mixture are substantially the same. In some embodiments, an active layer or electrode film formed from a dry particle active layer mixture using a dry manufacturing process may not contain, or substantially contain, any processing additives such as solvents and the resulting solvent residues. In some embodiments, the resulting active layer or electrode film is a self-supporting film formed using a drying process from a dry particle mixture. In some embodiments, the resulting active layer or electrode film is a self-supporting film formed using a drying process from a dry particle mixture. The process for forming the active layer or electrode film may include fibrillating a fibrillable binder component(s) such that the film contains a fibrillating binder. In further embodiments, the self-supporting active layer or electrode film may be formed in the absence of a current collector. In further embodiments, the active layer or electrode film may include a fibrillated polymer matrix such that the film is self-supporting. It is conceivable that a matrix, grid, or web of fibrils can be formed to provide a mechanical structure to the electrode film.

[0063] In some embodiments, the electrode film is placed on a current collector to form an electrode (e.g., a molded electrode). In some embodiments, the current collector may include a metallic material such as aluminum, nickel, copper, or a combination thereof. In some embodiments, the current collector may include a pure metal. In some embodiments, the current collector may include a metallized polymer film or a metal-coated polymer film. In some embodiments, the polymer may include polyethylene terephthalate (PET), biaxially oriented polypropylene (BOPP), or a combination thereof. In some embodiments, the metal coating may include aluminum. In some embodiments, coating the final electrode film mixture may involve forming a uniform electrode film mixture coating. In some embodiments, the current collector may include a thickness of 200 μm, 100 μm, 50 μm, 40 μm, 30 μm, 20 μm, 15 μm, 10 μm, 5 μm, or any range between these values, approximately these values, up to these values, or up to approximately these values.

[0064] In some embodiments, the electrode is a single-sided electrode. In some embodiments, the electrode is a double-sided electrode. In some embodiments, at least a portion of the electrode is a single-sided electrode and / or a double-sided electrode (for example, this portion is located at the end of the electrode). In some embodiments, the double-sided electrode includes two electrode films. In some embodiments, the double-sided electrode may include a current collector, an upper electrode film, and a lower electrode film. In some embodiments, each of the two electrode films may have any suitable shape, size, and thickness.

[0065] In some embodiments, the energy storage device includes a separator, an anode electrode, a cathode electrode, an electrolyte, and a housing, wherein the electrolyte, separator, anode electrode, and cathode electrode are arranged within the housing, and the separator is positioned between the anode electrode and the cathode electrode. In some embodiments, the energy storage device is formed by arranging the electrolyte, separator, anode electrode, and cathode electrode described herein within a housing, and the separator is positioned between the anode electrode and the cathode electrode.

[0066] The electrode assembly includes a cathode, an anode, and a separator positioned between the anode and the cathode. In some embodiments, the electrode assembly is a wound electrode (i.e., rolled electrode) assembly (e.g., a jelly roll). In some embodiments, the energy storage device is selected from the group consisting of cylindrical energy storage devices, stacked prismatic energy storage devices, and helically wound prismatic energy storage devices. In some embodiments, the molded edge substantially prevents the formation of electrode buckling zones or kinks within the electrode.

[0067] Normalized circularity can be used to identify and / or correlate relatively weak core spots (e.g., spots that may cause electrode buckling) in wound electrode assemblies. The normalized circularity of a non-ideal helix is ​​defined as the minimum ratio between the non-ideal (actual) geometric shape and the ideal geometric shape at each point, according to the following formula:

number

[0068] The geometric shape of a non-ideal (actual) spiral is given by measured Cartesian and polar coordinates (x,y,θ,r), while the geometric shape of an ideal spiral is derived from the Archimedean spiral according to r = αθ + β. The geometric shape of a spiral (ideal or non-ideal) can be characterized by curvature (K), such as the following polar curvature parameterization.

number

[0069] In some embodiments, the electrode assembly is 0.7, 0.705, 0.71, 0.715, 0.72, 0.725, 0.73, 0.735, 0.74, 0.745, 0.75, 0.76, 0.77, 0.78, 0.79, 0.8, 0.805, 0.81, 0.815, 0.82, 0.825, 0.83, 0.835, 0.84, 0.845, 0.85, 0.86, Includes normalized circularity values ​​that are 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1, 1.05, 1.1, 1.15, 1.2, or any range between them, approximately these values, at least these values, or at least approximately these values.

[0070] The electrodes disclosed herein can be used in energy storage devices. In some embodiments, the energy storage device includes a separator, an anode electrode, a cathode electrode, an electrolyte, and a housing, wherein the electrolyte, separator, anode electrode, and cathode electrode are arranged within the housing, and the separator is positioned between the anode electrode and the cathode electrode. In some embodiments, the energy storage device is formed by arranging the electrolyte, separator, anode electrode, and cathode electrode described herein within the housing, with the separator positioned between the anode electrode and the cathode electrode. In some embodiments, the energy storage device includes an anode electrode positioned between two cathode electrodes. In some embodiments, the anode electrode and / or cathode electrode includes a molded electrode film. In some embodiments, the energy storage device is a lithium-ion battery. In some embodiments, the energy storage device may be a battery, a capacitor, a capacitor-battery hybrid, a fuel cell, or a combination thereof. In some embodiments, the energy storage system or energy storage device may be used in electromobility. In some embodiments, the energy storage device can be used in vehicles including hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and / or electric vehicles (EVs). In some embodiments, the energy storage device used in vehicles including hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and / or electric vehicles (EVs) reduces greenhouse gas emissions.

[0071] In some embodiments, the energy storage device is charged with a suitable lithium-containing electrolyte. For example, the energy storage device may contain a lithium salt and a solvent such as a non-aqueous solvent or an organic solvent. Generally, the lithium salt contains a redox-stable anion. In some embodiments, the anion may be monovalent. In some embodiments, the lithium salt can be selected from lithium hexafluoride phosphate (LiPF6), lithium bis(trifluoromethanesulfonyl)imide (LiFSI), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium bis(trifluoromethanesulfonyl)imide (LiN(SO2CF3)2), lithium trifluoromethanesulfonate (LiSO3CF3), lithium bis(oxalato)borate (LiB(C2O4)2), lithium bis(fluorosulfonyl)imide (LiN(SO2F)2), lithium difluoro(oxalato)borate (LiC2BF2O4), and combinations thereof. In some embodiments, the electrolyte may include a quaternary ammonium cation and an anion selected from the group consisting of hexafluorophosphate, tetrafluoroborate, and iodide. In some embodiments, the salt concentration may be about 0.1 mol / L(M) to about 5 M, about 0.2 M to about 3 M, or about 0.3 M to about 2 M. In further embodiments, the salt concentration of the electrolyte may be about 0.7 M to about 2 M. In certain embodiments, the salt concentration of the electrolyte may be about 0.2 M, about 0.3 M, about 0.4 M, about 0.5 M, about 0.6 M, about 0.7 M, about 0.8 M, about 0.9 M, about 1 M, about 1.1 M, about 1.2 M, 1.3 M, 1.4 M, 1.5 M, or values ​​in between.

[0072] In some embodiments, the energy storage device may include a liquid solvent. The solvent does not need to dissolve all components of the electrolyte, nor does it need to completely dissolve any component. In further embodiments, the solvent may be an organic solvent. In some embodiments, the solvent may include one or more functional groups selected from dioxathiolane (e.g., 1,3,2-dioxathiolane-2,2-dioxide (i.e., "DTD")), carbonates, ethers and / or esters. In some embodiments, the solvent may include a carbonate. In further embodiments, the carbonate may be selected from cyclic carbonates, e.g., ethylene carbonate (EC), propylene carbonate (PC), vinylethylene carbonate (VEC), vinylene carbonate (VC), fluoroethylene carbonate (FEC) and combinations thereof, or acyclic carbonates, e.g., dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), 1,3-propensultone (PRS) and combinations thereof. In some embodiments, the solvent may include an ester. In some embodiments, the ester is selected from methyl acetate (MA), methyl propionate (MP), ethyl acetate (EA), methyl butyrate (MB), and combinations thereof. In some embodiments, the solvent may include EC, PC, VEC, VC, FEC, DMC, DEC, EMC, MA, MP, EA, MB, and combinations thereof. In some embodiments, the solvent may include EC, DMC, DEC, EMC, MA, and combinations thereof. In some embodiments, the solvent may include EC, DMC, EMC, and combinations thereof. In some embodiments, the solvent may include an EC:DMC:EMC ratio of 10-30:0-90:0-70.

[0073] In some embodiments, one or more solvents can be used at concentrations of 30% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight, 80% by weight, 85% by weight, or 90% by weight, or any range of values ​​between these, approximately these values, at least these values, or at least approximately these values. In some embodiments, the solvent is used as an additive in the electrolyte system at concentrations of 0.1% by weight, 0.2% by weight, 0.3% by weight, 0.4% by weight, 0.5% by weight, 0.6% by weight, 0.7% by weight, 0.8% by weight, 0.9% by weight, 1% by weight, 1.1% by weight, 1.2% by weight, 1.3% by weight, 1.4% by weight, 1.5% by weight, 1.6% by weight, 1.7% by weight, 1.8% by weight, 1.9% by weight, 2% by weight, 2.1% by weight It can be used at concentrations of 2.2 wt%, 2.3 wt%, 2.4 wt%, 2.5 wt%, 2.6 wt%, 2.7 wt%, 2.8 wt%, 2.9 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, or 10 wt%, or any range of values ​​in between, or approximately these values, or at most these values, or at most approximately these values. For example, in some embodiments, the amount of additive in the electrolyte is one of the ranges of 0.1 to 10 wt%, 1 to 6 wt%, 2 to 5 wt%, 0.1 to 6 wt%, 2 to 8 wt%, 2 to 3 wt%, or 1 to 4 wt%, or approximately these ranges.

[0074] In some embodiments, the energy storage device is constructed such that one electrode (e.g., the anode) is larger than and overhangs the other electrode (e.g., the cathode). One electrode may overhang the other in the winding direction and / or non-winding direction of the electrode assembly. Such electrode overhangs can avoid yield losses. In some embodiments, if there is no or substantially no overlap and / or mixing of the separator and the molded electrode film (e.g., the cathode electrode film), the boundary of the molded electrode film is easier to identify, and therefore the ability to form a counter electrode (e.g., the anode electrode) with an overhang is improved.

[0075] PCT patent application PCT / US2019 / 059691, filed on 4 November 2019, and PCT patent application PCT / US2021 / 050992, filed on 17 September 2021, are expressly incorporated herein by reference in their entirety for all purposes (e.g., the configuration of electrodes, electrode films, and current collectors). [Examples]

[0076] Exemplary embodiments of the present disclosure, including processes, materials, and / or resulting products, are described in the following examples.

[0077] Example 1 - Simulation of normalized circularity measurement Normalized circularity or winding circularity values ​​were simulated for various shaped electrode films. Compared to the baseline or unshaped electrode film (e.g., straight edge), other shapes such as angular, inverted or opposite angular, chevron, and inverted or opposite chevron showed a substantial increase in normalized circularity.

[0078] Example 2 - Normalized circularity measurement based on molded electrode film Normalized circularity or winding circularity was measured by taking a cross-section of the electrode assembly. Before testing, ten electrode assemblies, each having two different molded edges, straight edges, and square edges, were removed from the winding conveyor. Molded electrode films with square edges showed significantly higher normalized circularity values ​​compared to the baseline or unmolded electrode film (e.g., rectangular).

[0079] Example 3 - Electrode buckling based on the number of cycles Similar to Example 2, normalized circularity values ​​were measured by taking cross-sections of the electrode assemblies. Electrode assemblies with two different molded edges, straight edges, and V-shaped edges were incorporated into functional cells and sent for formation. Computed tomography (CT) scans were performed before the start of the cycle (e.g., 0 Wh / Wh), after 50 Wh / Wh, and after 100 Wh / Wh. Normalized circularity values ​​less than 0.6 were generally considered to be the threshold for electrode buckling of the electrode assembly, and therefore, cells with normalized circularity values ​​less than 0.6 were removed from the cycle test. Molded electrode films with V-shaped edges showed stable normalized circularity values ​​after 50 Wh / Wh and 100 Wh / Wh compared to baseline or unmolded electrode films (e.g., rectangular).

[0080] While specific embodiments of the present invention have been described, these embodiments are presented only as examples and are not intended to limit the scope of this disclosure. In fact, the novel methods and systems described herein can be embodied in a variety of other forms. Furthermore, various omissions, substitutions, and modifications can be made to the systems and methods described herein without departing from the spirit of this disclosure. The appended claims and their equivalents are intended to encompass forms or modifications that fall within the scope and spirit of this disclosure. Accordingly, the scope of the present invention is defined solely by reference to the appended claims.

[0081] Features, materials, properties, or groups described in relation to a particular aspect, embodiment, or example should be understood to be applicable to any other aspect, embodiment, or example described in this section or elsewhere in this specification, provided that they do not conflict. All features and / or any steps of any method or process disclosed herein (including any appended claims, abstract, and drawings) may be combined in any combination, except for any combination in which at least some of such features and / or steps are mutually exclusive. Protection is not limited to the details of any aforementioned embodiment. Protection extends to any novel features or any novel combination of features disclosed herein (including any appended claims, abstract, and drawings), or any novel steps or any novel combination of any steps of any method or process disclosed herein.

[0082] Furthermore, certain features described in this disclosure in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented separately or in any suitable combination of sub-features in multiple embodiments. Furthermore, while features may be described above as acting in a particular combination, one or more features from a claimed combination may, in some cases, be removed from the combination, and the combination may be claimed as a combination of sub-features or a variation of a combination of sub-features.

[0083] Furthermore, while operations may be shown in the drawings or described herein in a specific order, such operations do not need to be performed in the specific order shown or in a sequential order to achieve the desired result, nor do all operations need to be performed. Other operations not shown or described may be incorporated into exemplary methods and processes. For example, one or more additional operations may be performed before, after, simultaneously with, or in between any of the described operations. Furthermore, operations may be rearranged or reordered in other embodiments. Those skilled in the art will understand that in some embodiments, the actual steps performed in the illustrated and / or disclosed processes may differ from those shown in the drawings. Depending on the embodiment, certain steps among the steps described above may be omitted, or other steps may be added. Furthermore, the features and attributes of the particular embodiments disclosed above may be combined in different ways to form additional embodiments, all of which fall within the scope of this disclosure. Also, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and the described components and systems may generally be integrated together in a single product or packaged in multiple products. For example, any of the components of the energy storage system described herein may be provided separately or integrated (e.g., packaged together or mounted together) to form the energy storage system.

[0084] For the purposes of this disclosure, certain aspects, advantages, and novel features are described herein. Not all such advantages can necessarily be achieved according to any particular embodiment. Therefore, for example, a person skilled in the art will recognize that this disclosure can be implemented or carried out in a manner that achieves one advantage or set of advantages as taught herein, without necessarily achieving other advantages that can be taught or suggested herein.

[0085] Conditional language such as “can,” “could,” “might,” or “may” is generally intended to convey that a particular embodiment includes certain features, elements, and / or steps, but other embodiments do not, unless otherwise specified or understood in the context in which they are used. Therefore, such conditional language is generally not intended to imply that features, elements, and / or steps are required in one or more embodiments, or that one or more embodiments necessarily include logic for determining, with or without user input or prompting, whether these features, elements, and / or steps are included in or performed within any particular embodiment.

[0086] The phrase "at least one of X, Y, and Z" is generally understood in its context to mean that an item, term, etc., may be one of X, Y, or Z, unless otherwise specified. Therefore, such a phrase is not generally intended to imply that a particular embodiment requires the presence of at least one X, at least one Y, and at least one Z.

[0087] As used herein, the terms “approximately,” “about,” “generally,” and “substantially” refer to values, quantities, or characteristics close to the stated values, quantities, or characteristics that still perform the desired function or achieve the desired result. For example, the terms “approximately,” “about,” “generally,” and “substantially” may refer to quantities less than 10%, less than 5%, less than 1%, less than 0.1%, and less than 0.01% of the stated quantity, depending on the desired function or desired result.

[0088] The scope of this disclosure is not intended to be limited by any specific disclosure of preferred embodiments in this section or elsewhere in this specification, but may be defined by the claims, as presented in this section or elsewhere in this specification, or as presented in the future. The language of the claims should be interpreted broadly on the basis of the language adopted in the claims, and not limited to the examples described herein or during the examination of an application, and the examples should be interpreted as non-exclusive.

Claims

1. An energy storage device, The housing comprises an electrode assembly and an electrolyte, The electrode assembly comprises a first electrode, a second electrode, and a separator located between the first electrode and the second electrode. The first electrode comprises a molded electrode film and a current collector, and the molded electrode film is placed on the current collector. The molded electrode film includes an active material, a length, a length end, a width, wherein the length is greater than the width, and a molded edge located at the length end. An energy storage device in which the molded edge includes a taper angle and a taper distance.

2. A molded electrode film, Active material and, Length, end length and width, wherein the length is greater than the width, A molded edge located at the length end, wherein the molded edge includes a taper angle and a taper distance, A molded electrode film, including a molded electrode film.

3. The molded electrode film according to claim 2, further comprising a second molded edge located at a second length end.

4. The molded electrode film according to claim 2, wherein the molded edge is selected from the group consisting of a square edge, a double square edge, a V-shaped edge, a double V-shaped edge, a rounded edge, a double rounded edge, the opposite thereof, the reverse thereof, and combinations thereof.

5. The molded electrode film according to claim 2, wherein the taper angle is approximately 10° to 45°.

6. The molded electrode film according to claim 2, wherein the taper distance is approximately 25 mm or less.

7. A molded electrode comprising a molded electrode film according to claim 2 and a current collector, wherein the molded electrode film is disposed on the current collector.

8. An electrode assembly, The molded electrode according to claim 7, The second electrode and A separator located between the molded electrode and the second electrode, An electrode assembly comprising:

9. The electrode assembly according to claim 8, wherein the electrode assembly is a wound electrode assembly.

10. The electrode assembly according to claim 8, wherein the second electrode includes a second molded edge.

11. The electrode assembly according to claim 8, wherein the electrode assembly is selected from the group consisting of cylindrical energy storage devices and spirally wound prismatic energy storage devices.

12. The electrode assembly according to any one of claims 8 to 11, wherein the electrode assembly includes a normalized circularity value of at least about 0.

8.

13. The electrode assembly according to any one of claims 8 to 11, wherein the electrode assembly includes a normalized circularity value of at least about 0.

9.

14. An energy storage device, The electrode assembly according to claim 8, Electrolytes, A housing in which the electrode assembly and the electrolyte are disposed within the housing, An energy storage device equipped with the following features.

15. A method for forming a molded electrode film, A step of providing an electrode film including length, length end and width, wherein the length is greater than the width, The steps include: forming the length end so as to form a molded electrode film including a molded edge; Methods that include...

16. The method according to claim 15, further comprising the step of forming a molded electrode including the molded electrode film disposed on a current collector.

17. The method according to claim 16, wherein the current collector is a molded edge current collector.

18. The method according to claim 16, wherein an adhesive layer is disposed between the molded electrode film and the current collector.

19. The method according to claim 18, wherein the adhesive layer is a molded edge adhesive layer.

20. The method according to claim 15, further comprising the step of placing the electrode film on a current collector.

21. The method according to claim 20, wherein the step of forming the length end includes removing the scrap electrode film of the electrode film from the current collector.

22. The method according to claim 15, further comprising the step of placing the molded electrode film on a current collector.

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