Aqueous cathode slurry with dispersant

Abstract

An aqueous cathode slurry containing a dispersant is provided. A battery, a vehicle having a battery, and a method for manufacturing a battery are also provided. One method for manufacturing a battery includes: forming an amphiphilic polymer dispersant; forming an aqueous cathode material slurry by simultaneously or continuously adding the following substances to water: the amphiphilic polymer dispersant; a positively active material; and a binder; and forming a cathode from the aqueous cathode material slurry.

Description

Technical Field

[0001] The technical field generally relates to rechargeable batteries, and more specifically to methods for manufacturing cathodes that avoid the use of substandard materials. Background Technology

[0002] High-energy-density electrochemical cells (such as lithium-ion batteries) can be used in a variety of consumer products and vehicles, such as hybrid electric vehicles (HEVs) and electric vehicles (EVs). Typical lithium-ion and lithium-sulfur batteries include a first electrode, a second electrode, an electrolyte material, and a separator. One electrode serves as the positive electrode or cathode (during discharge), and the other electrode serves as the negative electrode or anode (during discharge). Stacking battery cells can electrically connect them to increase the total output. Typical rechargeable lithium-ion batteries operate by reversibly transferring lithium ions back and forth between the negative and positive electrodes. A separator and electrolyte are positioned between the negative and positive electrodes. The electrolyte is suitable for conducting lithium ions and can be in solid (e.g., solid-state diffusion) or liquid form. Lithium ions move from the cathode (positive electrode) to the anode (negative electrode) during battery charging and in the opposite direction during battery discharge.

[0003] To increase the overall energy density of the battery cell, it is desirable for the positive electrode or cathode to have a high loading density of positively active materials. For example, the greater the loading of the electroactive material, the greater the relative amount of positively active material compared to the inert materials (such as current collectors and separators) present in the electrochemical cell. However, in practice, the loading of the positive electrode electroactive material layer is limited due to the difficulty in processing and coating the slurry. For example, poor liquid-phase lithium-ion transfer kinetics and the lack of structural integrity in thick electrodes can impair electrochemical performance, thereby reducing lifetime and charge / fast-charge performance.

[0004] Therefore, it is desirable to form electrochemical cells or batteries comprising positive electrodes / cathodes that provide higher energy density to increase storage capacity and / or reduce battery size, while maintaining a cycle life similar to other lithium-ion batteries. It is further desirable to provide methods for manufacturing such positive electrodes / cathodes that avoid the use of substandard materials. Furthermore, other desirable features and characteristics of this disclosure will become apparent from the following detailed description and appended claims, taken in conjunction with the accompanying drawings and the foregoing introduction. Summary of the Invention

[0005] In one embodiment, a method for manufacturing a battery is provided, the method comprising: forming an amphiphilic polymer dispersant; forming an aqueous cathode material slurry by simultaneously or continuously adding the following substances to water: the amphiphilic polymer dispersant; a positively active material; and a binder; and forming a cathode from the aqueous cathode material slurry.

[0006] In some embodiments of the method, forming an amphiphilic polymer dispersant includes post-secondary modification of the maleic anhydride-containing polymer using an alkyl group having a nucleophilic functional group.

[0007] In some embodiments of the method, forming an amphiphilic polymeric dispersant includes: forming the polymeric dispersant having alkyl attachment functional groups and ionic functional groups.

[0008] In some embodiments of the method, the positively active material includes sulfur / carbon composites, lithium iron phosphate (LFP), lithium-ion manganese oxide (LMO), lithium manganese (LMN), nickel-cobalt-manganese-aluminum (NCMA), and / or combinations thereof.

[0009] In some embodiments of the method, the binder includes polyacrylic acid (PAA), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR), carbohydrates, latex and / or combinations thereof.

[0010] In some embodiments of the method, based on the total solid weight of the aqueous cathode material slurry, the solid content of the aqueous cathode material slurry is less than 5% by weight of amphiphilic polymer dispersant and at least 95% by weight of positively active material.

[0011] In some embodiments of the method, the positively active material includes a sulfur / carbon composite material, and the binder includes lithium-ionized polyacrylic acid (LiPAA).

[0012] In some embodiments of the method, the positively active material includes lithium iron phosphate (LFP) material, and the binder includes carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR).

[0013] In some embodiments of the method, the aqueous cathode material slurry is free of N-methyl-2-pyrrolidone (NMP).

[0014] In some embodiments of the method, forming the amphiphilic polymer dispersant includes: secondary post-modification of the maleic anhydride-containing polymer using an alkyl group having a nucleophilic functional group; the positively active material includes sulfur / carbon composites, lithium iron phosphate (LFP), lithium-ion manganese oxide (LMO), lithium manganese (LMN), nickel cobalt manganese aluminum (NCMA), and / or combinations thereof; the binder includes polyacrylic acid (PAA), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC), and styrene-butadiene rubber (SBR), carbohydrates, latex, and / or combinations thereof; based on the total solids weight of the aqueous cathode material slurry, the solids content of the aqueous cathode material slurry is less than 5% by weight of the amphiphilic polymer dispersant and at least 95% by weight of the positively active material; and the aqueous cathode material slurry is free of N-methyl-2-pyrrolidone (NMP).

[0015] In another embodiment, a battery includes: an anode current collector; an anode active material in direct contact with the anode current collector; a cathode current collector; a cathode layer in contact with the cathode current collector, wherein the cathode layer comprises a homogeneous mixture of an amphiphilic polymer dispersant, a positively active material, and a binder; a separator located between the anode active material and the cathode layer; and an electrolyte in contact with the anode active material and the cathode layer.

[0016] In some embodiments of the battery, the amphiphilic polymer dispersant is formed by secondary modification of the maleic anhydride-containing polymer using alkyl groups having nucleophilic functional groups.

[0017] In some embodiments of the battery, the amphiphilic polymer dispersant has alkyl attachment functional groups and ionic functional groups.

[0018] In some embodiments of the battery, the positively active material includes sulfur / carbon composites, lithium iron phosphate (LFP), lithium-ion manganese oxide (LMO), lithium manganese (LMN), nickel-cobalt-manganese-aluminum (NCMA), and / or combinations thereof.

[0019] In some embodiments of the battery, the binder includes polyacrylic acid (PAA), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR), carbohydrates, latex and / or combinations thereof.

[0020] In some embodiments of the battery, the cathode layer comprises a homogeneous mixture of an amphiphilic polymer dispersant, a positively active material, a binder, and an additional conductive material.

[0021] In another embodiment, a vehicle includes: an electric traction motor configured to provide power torque; and a battery system operatively connected to and operable to provide power to the electric motor, wherein the battery system includes a high-voltage rechargeable battery comprising a cell stack, wherein each cell stack includes a battery cell, wherein each battery cell includes: a cathode electrode formed from an aqueous slurry of an amphiphilic polymer dispersant, a positively active material, and a binder selected from polyacrylic acid (PAA), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC), and styrene-butadiene rubber (SBR), carbohydrates, latex, and / or combinations thereof; an anode electrode; a separator located between the anode electrode and the cathode electrode; and an electrolyte in contact with the anode electrode and the cathode electrode.

[0022] In some embodiments of the vehicle, the amphiphilic polymer dispersant is formed by secondary post-modification of a maleic anhydride-containing polymer using alkyl groups having nucleophilic functional groups.

[0023] In some embodiments of the vehicle, the amphiphilic polymeric dispersant has alkyl adhesion functional groups and ionic functional groups.

[0024] In some embodiments of the vehicle, the positively active material includes sulfur / carbon composites, lithium iron phosphate (LFP), lithium-ion manganese oxide (LMO), lithium manganese (LMN), nickel-cobalt-manganese-aluminum (NCMA), and / or combinations thereof. Attached Figure Description

[0025] The present disclosure will now be described in conjunction with the following accompanying drawings, wherein like reference numerals denote like elements, and wherein:

[0026] Figure 1 This is a functional block diagram of a vehicle according to an exemplary implementation, the vehicle including an RESS and a control system for controlling the RESS, as well as various other components;

[0027] Figure 2 yes Figure 1 A schematic diagram of the battery cells in the cell pack of a portion of the RESS;

[0028] Figure 3 It is operated in accordance with all aspects of this disclosure. Figure 1 A schematic diagram of a representative battery cell in a vehicle;

[0029] Figure 4 It is used to form for Figure 3 A schematic diagram of the chemical reaction of the polymer dispersant in the cathode of the battery cell; and

[0030] Figure 5 This is a flowchart illustrating methods for manufacturing a cathode and for manufacturing a battery according to various aspects of this disclosure. Detailed Implementation

[0031] The following detailed description is exemplary in nature only and is not intended to limit this disclosure or its application and use. Furthermore, it is not intended to be bound by any theory presented in the foregoing introduction or the content of the invention or the following detailed description.

[0032] The embodiments described herein provide a polymer dispersant for use in water-based cathode slurries during cathode manufacturing. The embodiments described herein include the synthesis of a class of polymer dispersants and their use in water-based cathode slurries.

[0033] Typically, cathode paste is formed from polyvinylidene fluoride (PVDF) binder dissolved in N-methyl-2-pyrrolidone (NMP). PVDF is considered a "permanent chemical," and its use is subject to strict regulations. Furthermore, the use of NMP may be undesirable and requires additional engineering controls and solvent recovery.

[0034] The embodiments described herein avoid using PVDF as a binder. Furthermore, the embodiments described herein avoid using NMP as a solvent.

[0035] Instead, the embodiments described herein provide the preparation and use of an aqueous cathode material slurry to form a cathode. This aqueous cathode material slurry and the resulting cathode are PVDF-free or substantially PVDF-free, and also NMP-free or substantially NMP-free.

[0036] As used herein, a slurry or cathode that is “substantially free” of the compound may be completely free of the compound, i.e., contain less than a detectable level of the compound. In some embodiments, a slurry or cathode that is “substantially free” of the compound may contain less than 0.05% by weight of the compound relative to the total weight of the slurry or cathode.

[0037] In some embodiments, the cathode active material may be a sulfur / carbon composite material used in combination with a lithium-ionized polyacrylic acid (LiPAA) binder. In some embodiments, the cathode active material may be lithium iron phosphate (LFP) used in combination with a CMC / SBR binder (carboxymethyl cellulose / styrene-butadiene rubber binder). While such combinations have been described, the embodiments herein are not limited to such cathode active materials and binders.

[0038] In fact, it has been established that the polymer dispersants described herein can be used in a variety of aqueous cathode chemicals and with a variety of binder systems.

[0039] Water-based cathode slurries often suffer from dispersion problems, resulting in poor coating quality and electrochemical performance. The embodiments described herein improve the dispersibility of the cathode active material slurry and enhance the quality of the cathode active material coating formed from it. Furthermore, the embodiments described herein provide a water-based cathode active material slurry with high loading capacity.

[0040] Figure 1 A vehicle 100 according to an exemplary implementation is shown. As described in more detail below, the vehicle 100 includes a rechargeable energy storage system (“RESS”) 101 and a control system 102, as well as other components. In various implementations, the RESS 101 includes multiple battery cell groups 170, for example, such as Figure 2 As shown and combined below Figure 2 A further, more detailed description follows. Similarly, in various implementations, control system 102 controls RESS 101.

[0041] like Figure 1 As shown, according to an exemplary implementation, RESS 101 and control system 102 are depicted as part of vehicle 100. In various implementations, vehicle 100 includes automobiles, such as any of a variety of different types of automobiles, such as, for example, sedans, vans, trucks, SUVs, etc. In some implementations, vehicle 100 may also include motorcycles or other vehicles, such as aircraft, spacecraft, ships, etc., and / or one or more other types of mobile platforms (e.g., robots and / or other mobile platforms). In other implementations, RESS 101 and control system 102 may alternatively be part of and / or coupled to any number of other types of mobile or non-mobile platforms and / or systems, such as buildings, infrastructure, secondary use, household electricity, non-automobile, and / or other platforms and / or systems.

[0042] In the depicted implementation, vehicle 100 includes a body 104 disposed on a chassis 116. The body 104 substantially surrounds the other components of vehicle 100. The body 104 and chassis 116 may together form a frame. Vehicle 100 also includes a plurality of wheels 112. Each wheel 112 is rotatably coupled to the chassis 116 near a corresponding corner of the body 104 to facilitate movement of vehicle 100. In one implementation, vehicle 100 includes four wheels 112, although this may vary in other implementations (e.g., for trucks, motorcycles, and certain other vehicles).

[0043] The drive system 110 is mounted on the chassis 116 and drives the wheels 112, for example, via axle 114. In some implementations, the drive system 110 includes a propulsion system with an electric motor 113. In various implementations, the drive system 110 including the motor 113 receives a high voltage from the RESS 101.

[0044] In various implementations, in addition to providing high voltage to motor 113, RESS 101 also provides low voltage to one or more low voltage systems 111 of vehicle 100. In various implementations, the low voltage system 111 may include, for example, one or more climate control systems, radio systems, seat heating systems, etc.

[0045] like Figure 1 As shown, in various implementations, the vehicle also includes a braking system 106 and a steering system 108. In an exemplary implementation, the braking system 106 uses braking components to control the braking of the vehicle 100, which are controlled via input provided by the driver (e.g., via the brake pedal) and / or automatically controlled via a control system (such as control system 102 and / or one or more other control systems). Similarly, in an exemplary implementation, the steering system 108 controls the steering of the vehicle 100 via steering components, which are controlled via input provided by the driver (e.g., via the steering wheel) and / or automatically controlled via a control system (such as control system 102 and / or one or more other control systems).

[0046] exist Figure 1 In the illustrated implementation, the control system 102 is coupled to RESS 101, receives input from RESS, and controls its functions. Furthermore, in some implementations, the control system 102 is coupled to one or more of the braking system 106, steering system 108, drive system 110, and / or low-voltage system 111, and in some implementations, it can also receive input from and / or control these additional systems.

[0047] Similarly, Figure 1 As shown, in various implementations, the control system 102 includes a sensor array or arrangement 120 and a control module 140 (or controller), as described in more detail below.

[0048] In various implementations, sensor array 120 includes various sensors that acquire sensor data from vehicle 100 for use in controlling RESS 101 and other functions. In the depicted implementation, sensor array 120 includes one or more voltage sensors 130, current sensors 132, temperature sensors 134, pressure sensors 136, gas sensors 137, and additional sensors 138.

[0049] In various implementations, the control module 140 is coupled to the sensor array 120 and receives sensor data from the sensor array. In various implementations, the control module 140 is further coupled to the RESS 101. Furthermore, in some implementations, the control module 140 may also be coupled to one or more other systems of the vehicle 100, such as the braking system 106, the steering system 108, the drive system 110, and / or a low-voltage system, for example, to receive inputs from these systems and / or to control these systems.

[0050] Similarly, Figure 1 As shown, in various implementations, the control module 140 includes a computer system and includes a processor 142, a memory 144, an interface 146, a storage device 148, and a computer bus 150.

[0051] Processor 142 performs the computational and control functions of control module 140 and may include any type of processor or multiple processors, a single integrated circuit (such as a microprocessor), or any suitable number of integrated circuit devices and / or circuit boards that work together to perform the functions of the processing unit. During operation, processor 142 executes one or more programs 152 contained in memory 144 and thus controls the general operation of control module 140 and the computer system of control module 140, typically in the process described herein.

[0052] Memory 144 can be any suitable type of memory, including various types of non-transitory computer-readable storage media. In some examples, memory 144 is located on and / or co-located with processor 142 on the same computer chip. In the depicted implementation, memory 144 stores the aforementioned program 152 as well as stored values ​​157 (e.g., lookup tables, thresholds, and / or other values ​​related to the control of RESS 101).

[0053] Interface 146 allows communication with the computer system of control module 140, for example, from a system drive and / or another computer system, and can be implemented using any suitable methods and means. In one implementation, interface 146 obtains various data from sensor array 120 and other possible data sources. Interface 146 may include one or more network interfaces for communicating with other systems or components. Interface 146 may also include one or more network interfaces for communicating with technicians, and / or one or more storage interfaces for connecting to storage devices such as storage device 148.

[0054] Storage device 148 can be any suitable type of storage device, including various types of direct-access storage and / or other memory devices. In one exemplary implementation, storage device 148 includes a program product from which memory 144 can receive program 152, which performs one or more implementations of one or more processes of this disclosure, such as... Figure 5 Method 500 steps and the following combination Figure 5 Further steps are described below. In another exemplary implementation, the program product may be stored directly in memory 144 and / or disk (e.g., disk 156) and / or otherwise accessed by that memory and / or disk, as described below.

[0055] Bus 150 is used to transmit programs, data, status, and other information or signals between various components of the computer system in control module 140. Bus 150 can be any suitable physical or logical device for connecting the computer system and components. This includes, but is not limited to, direct hardwired connections, fiber optic, infrared, and wireless bus technologies. During operation, program 152 is stored in memory 144 and executed by processor 142.

[0056] It should be understood that although this exemplary implementation is described in the context of a full-featured computer system, those skilled in the art will recognize that the mechanisms of this disclosure can be distributed as a program product having one or more types of non-transitory computer-readable signal-bearing media for storing the program and its instructions and for executing the distribution therein, such as a non-transitory computer-readable medium carrying the program and containing computer instructions stored therein for causing a computer processor (such as processor 142) to execute and run the program.

[0057] Figure 2 yes Figure 1 A functional diagram of a portion of RESS 101 (such as battery module 101). As shown, according to an exemplary implementation, the battery module includes multiple cell groups 170.

[0058] like Figure 2 As shown, in various implementations, battery module 101 includes multiple cell groups 170. In some embodiments, cell groups 170 are connected in series via busbar 180. Cell groups can be configured electrically in series (as shown) and / or in parallel. It should be understood that the number and configuration of cell groups 170 can vary in different implementations, and the subject matter described herein is not limited to any particular number, type, or configuration of cell groups 170. Busbar 180 can be connected to drive system 110.

[0059] In some embodiments, each cell pack 170 may include one or more battery cells 200 or other energy storage elements. As shown, the battery cells 200 may be arranged in a stack, such that the cell pack 170 is referred to as a cell stack 170. The battery cells 200 may be electrically configured in series or parallel to provide a desired DC voltage level and / or DC output current. Although each cell pack 170 is shown as including five battery cells 200, the number of battery cells 200 in each cell pack 170 may be any suitable number desired.

[0060] Figure 3 An exemplary electrochemical device in the form of a rechargeable battery 310 is presented, which is for a desired electrical load (such as... Figure 1 The battery 310 provides power to the vehicle 10 and offers fast charging capabilities, such as DCFC. The battery 310 includes a pair of conductive electrodes encapsulated within a protective casing 320, namely, a first (negative or anode) working electrode 322 and a second (positive or cathode) working electrode 324. In at least some configurations, the battery casing 320 may be an envelope-like bag formed from aluminum foil or other suitable sheet material. The sides of the metal bag may be coated with a polymer topcoat to insulate the metal from the internal cell elements and adjacent cells (if any). Alternatively, the battery casing (or “cell housing”) 320 may be configured as a cylindrical metal can, i.e., for cylindrical battery cell configurations, or as a polyhedral metal box, i.e., for prismatic battery cell configurations. Referring to the working electrodes 322, 324 as “anode” or “cathode,” or for this purpose, “positive” or “negative,” does not limit the electrodes 322, 324 to a specific polarity, as the system polarity can vary depending on whether the battery 310 is operating in a charging or discharging mode. Figure 3 A single battery cell unit (such as...) inserted into the battery casing 320 is shown. Figure 2 The battery cell 200), but it should be understood that the casing 320 may house a stack of multiple cell units (e.g., five to five thousand cells or more), such as Figure 2 The stack is 170.

[0061] Continue to refer to Figure 3The anode electrode 322 can be manufactured using an active anode electrode material capable of binding ions during battery charging operation and releasing ions during battery discharging operation. In at least some implementations, the anode electrode 322 is made wholly or partially of lithium metal, such as lithium-aluminum (LiAl) alloys with a Li / Al atomic ratio in the range of 0 atomic% ≤ Li / Al < 70 atomic% and / or aluminum alloys with an Al atomic ratio > 50 atomic% (e.g., the lithium metal is smelted). Additional examples of suitable active anode electrode materials include carbonaceous materials (e.g., graphite, hard carbon, soft carbon, etc.), silicon, silicon-carbon blends (silicon-graphite composites), and Li4Ti5O. 12 Transition metals (alloy types, such as Sn), metal oxides / sulfides (e.g., SnO2, FeS, etc.), etc.

[0062] A porous membrane 326 is disposed within the battery casing 320 between the two electrodes 322 and 324. This porous membrane may have the properties of a microporous or nanoporous polymer membrane. The porous membrane 326 may comprise a non-aqueous fluid electrolyte composition and / or a solid electrolyte composition, collectively referred to as 330, which may also be present in the negative electrode 322 and the positive electrode 324. A negative electrode current collector 332 may be located on or near the negative electrode 322, and a positive electrode current collector 334 may be located on or near the positive electrode 324. The negative electrode current collector 332 and the positive electrode current collector 334 respectively collect free electrons and move them into and out of the external circuit 340. An interruptible external circuit 340 with a load 342 is connected to the negative electrode 322 via a corresponding current collector 332 and electrode tab 336, and to the positive electrode 324 via a corresponding current collector 334 and electrode tab 338. Current collectors 332 and 334 can be formed of aluminum, copper, or another suitable material. The diaphragm 326 can be a sheet-like structure composed of a porous polyolefin membrane, for example, with a porosity of about 35% to 65% and a thickness of about 25 to 30 micrometers. Non-conductive ceramic particles (e.g., silicon dioxide) can be coated on the porous membrane surface of the diaphragm 326.

[0063] The porous membrane 326 can function as an electrical insulator and mechanical support structure by being sandwiched between the two electrodes 322, 324 to prevent physical contact between the electrodes and thus prevent short circuits. In addition to providing a physical barrier between the electrodes 322, 324, the porous membrane 326 can also provide a path of least resistance for the internal passage of ions (and associated anions) during ion cycling, thus facilitating the operation of the battery 310. For some optional configurations, the porous membrane 326 can be a microporous polymer membrane comprising a polyolefin. The polyolefin can be a homopolymer derived from a single monomer component or a hybrid polymer derived from more than one monomer component, and can be linear or branched. In solid-state batteries, the function of the membrane can be partially or entirely provided by the solid electrolyte layer.

[0064] Battery 310 operates as a rechargeable energy storage system (RESS), generating current that is transmitted to one or more loads 342 operatively connected to an external circuit 340. While loads 342 can be any number of electrical devices, some non-limiting examples of power-consuming load devices include electric motors for hybrid or all-electric vehicles, laptop or tablet computers, cellular smartphones, cordless power tools and appliances, portable power stations, etc. Battery 310 may include a variety of other components, which, although not shown herein for simplicity and brevity, are still readily available. For example, battery 310 may include one or more gaskets, terminal caps, tabs, battery terminals, and other commercially available components or materials that may be located on or within battery 310. Furthermore, the size, shape, and operating characteristics of battery 310 may vary depending on the specific application it is designed for.

[0065] Positively active materials / active cathode materials

[0066] The cathode electrode 324 can be made of a positively electroactive material, i.e., an active cathode electrode material capable of supplying ions during battery charging operation and binding ions during battery discharging operation. The cathode electrode 324 material may include, for example, lithium transition metal oxides, phosphates, or silicates, such as LiMO2 (M = Co, Ni, Mn, or combinations thereof); LiM2O4 (M = Mn, Ti, or combinations thereof); LiMPO4 (M = Fe, Mn, Co, or combinations thereof); and LiM x M′ 2-xO4 (M, M′ = Mn or Ni). Other examples of suitable active cathode electrode materials include lithium nickel cobalt manganese oxide (NCM), lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese aluminum oxide (NCMA), and other lithium transition metal oxides. The active cathode electrode material can also be a sulfur / carbon composite or include sulfur / carbon composite materials. For example, the active cathode electrode material may include sulfur located in a porous carbon shell, which may optionally be coated with a polymer containing nitrogen atoms. Other composite material structures may be suitable. In some embodiments, the active cathode electrode material is selected from sulfur / carbon composites, lithium iron phosphate (LFP), lithium-ion manganese oxide (LMO), lithium manganese (LMN), nickel cobalt manganese aluminum (NCMA), and / or combinations thereof.

[0067] conductive materials

[0068] In the embodiments described herein, in addition to the active cathode electrode material, the second (positive or negative) working electrode 324 also includes an additional conductive material. The conductive material may be selected from carbon-based materials, nickel powder or other metal particles, or conductive polymers. Carbon-based materials may include, for example, graphite particles, acetylene black (such as denka), etc. TM Black), carbon black (such as KETJEN) TM Black and / or Super C45 or C65), carbon fibers and nanotubes (such as single-walled carbon nanotubes), graphene, graphene nanosheets, or other suitable conductive materials. Examples of conductive polymers include polyaniline, polythiophene, polyacetylene, polypyrrole, etc.

[0069] adhesive

[0070] In the embodiments described herein, the second (positive or negative) working electrode 324 further includes a binder material. In some embodiments, the adhesive material is selected from styrene-butadiene rubber, acrylic styrene-butadiene rubber, acrylonitrile copolymer, acrylonitrile-butadiene rubber, nitrile rubber, acrylonitrile-styrene-butadiene copolymer, acrylic rubber, butyl rubber, fluororubber, polytetrafluoroethylene, polyethylene, polypropylene, ethylene / propylene copolymer, polybutadiene, polyethylene oxide, chlorosulfonated polyethylene, polyvinylpyrrolidone, polyvinylpyridine, polyvinyl alcohol, polyvinyl acetate, polyepoxychloropropane, polyphosphazene, polyacrylonitrile, polystyrene, latex, acrylic resin, phenolic resin, epoxy resin, carboxymethyl cellulose, hydroxypropyl cellulose, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl cellulose, cyanoethyl sucrose, polyester, polyamide, polyether, polyimide, polycarboxylic acid ester, polycarboxylic acid, polyacrylic acid, polyacrylate, polymethacrylic acid, polymethacrylate, polyacrylamide, polyurethane, fluorinated polymer, chlorinated polymer, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, and combinations thereof. For example, the adhesive material may be polyacrylic acid (PAA), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR), carbohydrates, latex and / or combinations thereof.

[0071] Amphiphilic dispersants

[0072] The second (positive or negative) working electrode 324 also includes an amphiphilic dispersant. As described below, electrode 324 is formed from a slurry. In the embodiments described herein, the slurry is aqueous. In order to form a high-quality coating from the slurry, the binder must be dispersed throughout the aqueous slurry. Therefore, a dispersant is provided in the slurry.

[0073] In some embodiments herein, the dispersant has alkyl adhesion functional groups and ionic functional groups.

[0074] In some embodiments, the dispersant is formed by secondary post-modification of the maleic anhydride-containing polymer using alkyl groups having nucleophilic functional groups. For example, the polymer can be reacted with a base and excess alcohol or amine, and then neutralized to provide a lithium cation (Li+) to the product. Therefore, the compound used for neutralization can contribute the lithium cation. Lithium hydroxide can be a neutralizing compound because it readily contributes its lithium cation during neutralization.

[0075] In some embodiments, the dispersant is formed by nucleophilic substitution on a maleic anhydride-containing polymer. During nucleophilic substitution in a maleic anhydride-containing polymer, a nucleophile (a molecule with a lone pair of electrons) attacks the electrophilic anhydride ring within the polymer containing the maleic anhydride unit, causing the ring to open and form a new chemical bond with the nucleophile, essentially introducing a new functional group into the polymer chain.

[0076] Figure 4 An exemplary reaction is shown in which the polymer 410 containing maleic anhydride is poly(methyl vinyl ether-alt-maleic anhydride). Poly(methyl vinyl ether-alt-maleic anhydride) 410 reacts with excess isobutanol 420 and is then neutralized with lithium hydroxide 430 to form dispersant 490. As shown, dispersant 490 has alkyl attachment functional groups 491 and ionic functional groups 492.

[0077] Although Figure 4 The use of alkyl groups with nucleophilic functional groups for secondary post-modification of maleic anhydride-containing polymers is shown, but other methods can also be used to form dispersant 490. For example, a polymerization process can be performed to directly form dispersant 490 without the need for a post-polymerization modification step.

[0078] Cathode composition

[0079] In some embodiments, the cathode electrode 324 comprises 80% to 99.5% by weight of active cathode electrode material, including all values ​​and ranges therein. For example, based on the total weight of the cathode electrode 324, the cathode electrode 324 may comprise at least 80% by weight, at least 85% by weight, at least 90% by weight, at least 95% by weight, at least 96% by weight, at least 97% by weight, at least 98% by weight, or at least 99% by weight of active cathode electrode material. Furthermore, based on the total weight of the cathode electrode 324, the cathode electrode 324 may comprise at most 85% by weight, at most 90% by weight, at most 95% by weight, at most 96% by weight, at most 97% by weight, at most 98% by weight, at most 99% by weight, or at most 99.5% by weight of active cathode electrode material.

[0080] In some embodiments, the cathode electrode 324 includes 0.1% to 10% by weight of additional conductive material (if present), based on the total weight of the cathode electrode 324, including all values ​​and ranges therein.

[0081] In some embodiments, the cathode electrode 324 includes 0.1% to 10% by weight of binder, including all values ​​and ranges thereof, based on the total weight of the cathode electrode 324.

[0082] In some embodiments, the cathode electrode 324 comprises 0.1% to 5% by weight of a dispersant, including all values ​​and ranges thereof, based on the total weight of the cathode electrode 324.

[0083] Figure 5 This is a flowchart illustrating a method 500 for manufacturing a battery similar to the one described above. As shown, method 500 may include forming a cathode at operation 510.

[0084] Operation 510 may include preparing a cathode slurry at operation 511. Operation 511 may include simultaneously or continuously adding a positively active material, one or more binders, optionally one or more conductive materials, and a polymeric dispersant to water to form a combination.

[0085] Operation 510 may include grinding the mixture at operation 512 using a mixer. The mixer may be a planetary, high-speed, acoustic, static mixer, extruder, or melter. Grinding may be performed for an appropriate time period and at an appropriate speed, and the mixture may be maintained at approximately ambient temperature or room temperature (e.g., greater than or equal to about 15°C to less than or equal to about 40°C) during the grinding process. In some embodiments, the slurry may be mixed at a rate of 500 rpm to 3000 rpm for 2 to 10 minutes. After mixing, the slurry is a homogeneous mixture, i.e., the slurry has a substantially uniform consistency. In other words, each component is uniformly dispersed throughout the slurry.

[0086] When the slurry is prepared in this manner, the solid portion of the slurry may include: 80% to 99.5% by weight of active cathode electrode material, including all values ​​and ranges therein; 0.1% to 10% by weight of additional conductive material (if present), including all values ​​and ranges therein; 0.1% to 10% by weight of binder, including all values ​​and ranges therein; and 0.1% to 5% by weight of dispersant, including all values ​​and ranges therein, all based on the total solid weight of the slurry.

[0087] After preparing the cathode paste, operation 510 may further include, at operation 513, contacting the positive electrode or cathode material paste with one or more surfaces of the positive electrode current collector (e.g., an aluminum current collector). As a non-limiting example, contact may include coating one or more surfaces of the positive electrode current collector using, for example, a doctor blade or an automated coating machine.

[0088] As shown in the figure, operation 510 may further include drying the applied slurry at operation 514 to form an electroactive material layer on or near one or more surfaces of the current collector. In some variations, drying may include heating the current collector and the electroactive material layer to approximately 70°C. During drying, the temperature may be maintained at no higher than 200°C.

[0089] Operation 510 may also include, at operation 515, calendering the electroactive material layer at room temperature to form an electroactive material layer having a porosity greater than or equal to about 25 vol% to less than or equal to about 50 vol%, and in some respects, greater than or equal to 25 vol% to less than or equal to 50 vol%.

[0090] After calendering the slurry layer, the layer is processed and a cathode electrode 324 is formed. Therefore, method 500 can be considered to include forming a cathode from the slurry at 510, which includes forming the slurry, applying the layer, drying the layer, and calendering the layer.

[0091] In method 500, the cathode electrode formed from the electroactive material layer can be fabricated to have a capacity of at least about 4.0 mAh / cm². 2 (and in some respects, at least 4.5mAh / cm) 2 Or at least 5.0mAh / cm 2 The target surface capacity.

[0092] After the cathode electrode 324 is formed, method 500 continues at operation 560, assembling the battery 310 and its cells. For example, the cathode electrode 324 and the current collector 334 may be positioned in the battery casing 320 and separated from the anode electrode 322 and the current collector 332 by a porous separator 326, and in contact with the electrolyte composition 330.

[0093] Subsequently, method 500 may include a cycle of performing the charging and discharging process at operation 570. Subsequently, method 500 may include operating a device (such as vehicle 10) using electricity from the battery at operation 580.

[0094] In the first example, the slurry was formed by adding a carbon / sulfur composite cathode active material, a LiPAA binder, and an isobutyl-containing polymer dispersant to water, without adding any conductive material. The slurry solids composition consisted of 0.25% by weight of the polymer dispersant. The cathode was formed from the slurry as described above.

[0095] Compared to typical carbon / sulfur cathodes formed using PVDF binder and NMP solvent, the water-based cathode in this example exhibits similar or improved discharge capacity retention. Furthermore, the water-based cathode in this example demonstrates a particle size reduction of 70 micrometers to 40 micrometers.

[0096] In the second example, the slurry was formed by adding LFP cathode active material, CMC / SBR binder, and isobutyl-containing polymer dispersant to water, without adding any conductive material. The slurry solids composition was 97 wt% LFP cathode active material, 0.5 wt% polymer dispersant, and 2.5 wt% CMC / SBR binder. The cathode was formed from the slurry as described above.

[0097] Compared to typical LFP cathodes formed using PVDF binder and NMP solvent, the water-based cathode in this example exhibits similar or improved discharge capacity retention and increased loading, such as with 4.0 mAh / cm³. 2 In comparison, it reaches 4.5mAh / cm 2.

[0098] It should be understood that the battery, vehicle, and method may differ from those shown in the figures and described herein. Similarly, it should be understood that the operation of the method may differ from that depicted in the figures, and / or various operations of the method may occur simultaneously and / or in a different order than those shown and / or described above.

[0099] Although at least one exemplary embodiment has been presented in the foregoing detailed description, it should be understood that numerous variations exist. It should also be understood that the exemplary embodiments or multiple exemplary embodiments are merely examples and are not intended to limit the scope, applicability, or configuration of this disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient roadmap for implementing the exemplary embodiments or multiple exemplary embodiments. It should be understood that various changes can be made to the function and arrangement of the elements without departing from the scope of this disclosure as set forth in the appended claims and their legal equivalents.

Claims

1. A method for manufacturing a battery, the method comprising: Forms an amphiphilic polymer dispersant; Aqueous cathode material slurry is formed by adding the following substances to water simultaneously or continuously: The amphiphilic polymer dispersant; Positively active materials; and Adhesives; and The cathode is formed from the aqueous cathode material slurry.

2. The method of claim 1, wherein forming the amphiphilic polymer dispersant comprises: Polymers containing maleic anhydride are modified by secondary modification using alkyl groups with nucleophilic functional groups.

3. The method of claim 1, wherein forming the amphiphilic polymer dispersant comprises: The amphiphilic polymer dispersant is formed to have alkyl adhesion functional groups and ionic functional groups.

4. The method according to claim 1, wherein the positively active material comprises sulfur / carbon composite material, lithium iron phosphate (LFP), lithium-ion manganese oxide (LMO), lithium manganese (LMN), nickel-cobalt-manganese-aluminum (NCMA) and / or combinations thereof.

5. The method of claim 1, wherein the adhesive comprises polyacrylic acid (PAA), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR), carbohydrates, latex and / or combinations thereof.

6. The method of claim 1, wherein the positively active material comprises a sulfur / carbon composite material, and wherein the binder comprises lithium-ionized polyacrylic acid (LiPAA).

7. The method according to claim 1, wherein the positively active material comprises lithium iron phosphate (LFP) material, and wherein the binder comprises carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR).

8. The method according to claim 1, wherein the aqueous cathode material slurry is free of N-methyl-2-pyrrolidone (NMP).

9. The method according to claim 1, wherein: The formation of the amphiphilic polymer dispersant includes: secondary post-modification of the polymer containing maleic anhydride using an alkyl group having a nucleophilic functional group; The positively active materials include sulfur / carbon composite materials, lithium iron phosphate (LFP), lithium-ion manganese oxide (LMO), lithium manganese (LMN), nickel cobalt manganese aluminum (NCMA), and / or combinations thereof; The adhesives include polyacrylic acid (PAA), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR), carbohydrates, latex and / or combinations thereof; Based on the total solid weight of the aqueous cathode material slurry, the solid content of the aqueous cathode material slurry is less than 5% by weight of the amphiphilic polymer dispersant and at least 95% by weight of the positively active material; and The aqueous cathode material slurry does not contain N-methyl-2-pyrrolidone (NMP).

10. A battery, the battery comprising: Anode current collector; An anode active material, wherein the anode active material is in direct contact with the anode current collector; Cathode current collector; A cathode layer that contacts the cathode current collector, wherein the cathode layer comprises a homogeneous mixture of an amphiphilic polymer dispersant, a positively active material, and a binder; A diaphragm is located between the anode active material and the cathode layer; and An electrolyte that is in contact with the anolyte and the cathode layer.

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