Patent Application
20250233122
This application claims the benefit of Chinese Patent Application No. 202410065615.6, filed on Jan. 16, 2024. The entire disclosure of the application referenced above is incorporated herein by reference.
The information provided in this section is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
The present disclosure relates to battery cells, and more particularly to anode electrodes and methods for manufacturing anode electrodes for battery cells.
Electric vehicles (EVs) such as battery electric vehicles (BEVs), hybrid vehicles, and/or fuel cell vehicles include one or more electric machines and a battery system including one or more battery cells, modules, and/or packs. A power control system is used to control charging and/or discharging of the battery system during charging and/or driving.
Battery cells include cathode electrodes, anode electrodes, and separators. The cathode electrodes include a cathode active material layer arranged on a cathode current collector. The anode electrodes include an anode active material layer arranged on an anode current collector.
A method for manufacturing an anode electrode for a battery cell includes supplying a roughened anode current collector from a roll-to-roll chamber to a magnetron sputtering chamber; routing the roughened anode current collector around a roller in the magnetron sputtering chamber; using T sputtering targets arranged circumferentially around a portion of the roller, sputtering an amorphous silicon layer onto the roughened anode current collector to form an anode electrode, where T is an integer greater than one; and receiving the anode electrode from the magnetron sputtering chamber at the roll-to-roll chamber.
In other features, the roughened anode current collector is made of a material selected from a group consisting of copper, stainless steel (SS), nickel (Ni), titanium (Ti), and tin (Sb). The roughened anode current collector has a roughness (Rz) in a range from 0.1 μm to 12 μm. A thickness of the roughened anode current collector is in a range from 0.1 μm to 40 μm. A thickness of the amorphous silicon layer is in a range from 0.1 μm to 20 μm.
In other features, the amorphous silicon layer comprises a plurality of silicon columns. A diameter of the plurality of silicon columns is in a range from 0.1 μm to 15 μm. An average areal capacity of the anode electrode is in a range from 4 to 30 mAh/cm2.
In other features, a DC bias voltage of the magnetron sputtering chamber is in a range from 100V to 1000V. A cathode power of the magnetron sputtering chamber is in a range from 0.5 KW to 30 kW.
A battery cell includes A anode electrodes, wherein each of the A anode electrodes includes a roughened anode current collector. An anode active material layer includes an amorphous silicon layer deposited using physical vapor deposition (PVD) onto the roughened anode current collector C cathode electrodes including a cathode current collector and a cathode active material layer are arranged on the cathode current collector. The battery cell includes S separators, where A, C and S are integers greater than one.
In other features, the roughened anode current collector is made of a material selected from a group consisting of copper, stainless steel (SS), nickel (Ni), titanium (Ti), and tin (Sb). The roughened anode current collector has a roughness (Rz) in a range from 0.1 μm to 12 μm. A thickness of the roughened anode current collector is in a range from 0.1 μm to 40 μm. A thickness of the amorphous silicon layer on the roughened anode current collector is in a range from 0.1 μm to 20 μm. The amorphous silicon layer comprises a plurality of silicon columns.
In other features, a diameter of the plurality of silicon columns is in a range from 0.1 μm to 15 μm. An average areal capacity is in a range from 4 to 30 mAh/cm2.
A system for manufacturing an anode electrode for a battery cell includes a roll-to-roll chamber and a magnetron chamber including a roller and T sputtering targets arranged circumferentially around a portion of the roller where T is an integer greater than one. The roll-to-roll chamber supplies a roughened anode current collector to the magnetron sputtering chamber. The roughened anode current collector is routed around the roller in the magnetron sputtering chamber. The T sputtering targets sputter an amorphous silicon layer onto the roughened anode current collector to form an anode electrode. The anode electrode is routed from the magnetron sputtering chamber to the roll-to-roll chamber.
Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims, and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.
The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:
In the drawings, reference numbers may be reused to identify similar and/or identical elements.
While battery cells according to the present disclosure are shown in the context of electric vehicles, the battery cells can be used in stationary applications and/or other applications.
Silicon is a promising candidate as an anode active material due to multiple lithium ion (Li+) diffusion paths and high theoretical capacity. Developing high performance sheet-type silicon anodes is important for constructing practical lithium-ion batteries. Generally, the sheet-type silicon anode is fabricated using a wet-coating method. However, delivered rate capability and cycling of the anode electrode still need to be enhanced.
The present disclosure relates to a method for manufacturing an anode electrode including an amorphous silicon anode layer (e.g., including silicon columns) deposited onto a roughened copper current collector. The anode electrode can be produced using a scalable roll-to-roll manufacturing process.
Conventional wet coating processes mix an anode active material, a conductive additive, a binder, and a solvent into a mixture. The mixture is cast onto an anode current collector and then a drying stage is used to remove the solvent. The solvent has environmental issues and the drying stage increase the footprint of the process.
The manufacturing method according to the present disclosure for the anode electrode uses magnetron sputtering. This approach eliminates the use of the binder, the conductive additive, and the solvent, which simplifies the silicon anode fabrication process while increasing energy density. In addition, the amorphous silicon layer includes accidented surfaces. The accidented surfaces enable more contact interfaces with the electrolyte to increase Li-ion conduction paths and help release stress during silicon volume change during cycling.
Referring now to
In some examples, the anode active material layer 42 includes a silicon layer PVD-deposited onto the anode current collector 46. The anode current collector 46 comprises a roughened current collector. In some examples, the cathode active material layers 24 comprise coatings including one or more active materials, one or more conductive additives, and/or one or more binder materials that are applied (cast or laminated) onto the current collectors.
In some examples, the cathode current collector 26 comprises metal foil, metal mesh, perforated metal, 3 dimensional (3D) metal foam, and/or expanded metal. In some examples, the cathode current collectors are made of one or more materials selected from a group consisting of stainless steel, brass, bronze, zinc, and aluminum. External tabs 28 and 48 are connected to the current collectors of the cathode electrodes and anode electrodes, respectively, and can be arranged on the same or different sides of the battery cell stack 12. The external tabs 28 and 48 are connected to terminals of the battery cells.
In some examples, the battery cell 10 uses liquid electrolyte 52. In other examples, a solid-solid electrolyte, a gel electrolyte, and/or liquid electrolyte are used.
Referring now to
When the DC voltage is 100 to 500 V (e.g., 350-500V) and/or the cathode power is 0.5 to 12 KW (e.g., 10KW), the silicon is uniformly and gently deposited onto the roughened current collector to form silicon columns that include convex spherical surfaces. In some examples, a height of the amorphous silicon layer on roughened anode current collector (e.g., HS1≈HS2≈HSn) is in a range from 0.1 μm to 20 μm. In some examples, a diameter of the silicon columns (e.g., DS1≈DS2≈DSn) is in a range from 0.1 μm to 15 μm. In some examples, an average areal capacity is in a range from 4 to 30 mAh/cm2 (e.g., 10 to 20 mAh/cm2 for double-sided).
In some examples, the roughened anode current collector includes a roughened surface to enable tight interfaces with the amorphous silicon layer. In some examples, the roughened anode current collector has a roughness (Rz) in a range from 0.1 μm to 12 μm (e.g., 8 μm). In some examples, the thickness of the roughened anode current collector (e.g., HC1, HC2, HCn) is in a range from 0.1 μm to 40 μm. In some examples, the roughened anode current collector is made of a material selected from a group consisting of copper, stainless steel, nickel (Ni), titanium (Ti), and tin (Sn).
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During deposition, a process gas mixture such as argon (Ar) from a gas source 222 is introduced into the processing chamber 210 while AC and/or DC power is supplied. In some examples, a mass flow controller 224 and a valve 226 are used to meter the process gas from the gas source 222 into the processing chamber 210. A throttle valve 234 and/or pump 238 control pressure within the processing chamber 210 and/or evacuate reactants from the processing chamber 210. A DC source 244 supplies DC voltage to the magnetron cathode 216. An AC source 246 supplies AC voltage to the magnetron cathode 216.
During deposition, a target material (e.g., silicon) is ejected from the target 218 and deposited on the roughened anode current collector 46. Material is also sputtered from an exposed surface of the roughened anode current collector 46. In some examples, a silicon target (e.g., n-type; 99.995%) sputters silicon particles onto a porous anode current collector (e.g., copper mesh). In some examples, the DC source 244 supplies DC voltage in a range from 100V to 1000V. In some examples, cathode power from the AC source 246 is in a range from 0.5 to 30 KW at a frequency in a range from 20 to 200 KHz. In some examples, the width of the current collector is in a range from 10 to 500 cm. In some examples, the process may be performed on the same side two or more times to increase the thickness of the amorphous silicon layer.
In some examples, the sputtering is performed on a continuous current collector in a roll-to-roll process. The speed of the roll to roll process is in the range from 2 m/min to 20 m/min. In some examples, the width of the anode current collector is in a range from 10 cm to 500 cm. Since this is a solvent-free fabrication process, there is no need for environmental control for solvent usage or drying stages to remove the solvent. The anode electrode has good mechanical flexibility which increases durability.
Referring now to
After the target sputters amorphous silicon onto the current collector 312 at the plurality of sputtering targets 334-1, 334-2, . . . , and 334-T, an electrode 344 (the current collector 312 and the sputtered amorphous silicon layer) exits the magnetron sputtering chamber 330 through an elongated hole 327 (e.g., acting as a vacuum seal) and enters the roll-to-roll chamber 310. The electrode 344 passes over tension rollers 350 and 354, around a roller 358, and is collected on a roll 362.
Vacuum within the roll-to-roll chamber 310 can be controlled using a valve 370 and a pump 372 connected to an exhaust system 374. Vacuum within the magnetron sputtering chamber 330 can be controlled using a valve 380 and a pump 382 connected to an exhaust system 384. A process gas mixture including one or more gases (e.g., argon (Ar)) can be supplied using one or more gas sources, mass flow controllers 292, and/or valves 294.
The roughened copper current collector (e.g., foil) is supplied using a roll-to-roll approach. A silicon layer is continuously deposited by a magnetron sputtering chamber in an argon atmosphere from multiple silicon targets onto the roughened copper current collector. After sputtering, the anode electrode is collected onto a roll. The process on the other side of the current collector to obtain double-side anode electrodes.
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The anode electrode described herein does not include the ionically insulating binder which enhances power capability. In addition, the carbon additive is removed which eliminates the adverse reactions with electrolyte (e.g., solid electrolyte) which prolongs the cell cycle life.
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The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the disclosure can be implemented in and/or combined with features of any of the other embodiments, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with one another remain within the scope of this disclosure.
Spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed.” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”
In the figures, the direction of an arrow, as indicated by the arrowhead, generally demonstrates the flow of information (such as data or instructions) that is of interest to the illustration. For example, when element A and element B exchange a variety of information but information transmitted from element A to element B is relevant to the illustration, the arrow may point from element A to element B. This unidirectional arrow does not imply that no other information is transmitted from element B to element A. Further, for information sent from element A to element B, element B may send requests for, or receipt acknowledgements of, the information to element A.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2024100656156 | Jan 2024 | CN | national |
