Method and system for expandable direct recycling of batteries

Abstract

To provide a method and a system for excellent scalable direct recycling of batteries.SOLUTION: A method includes processing at least one battery into a plurality of core sections. Each core section in the plurality of core sections includes an anode section, a cathode section including a cathode material, a separator section disposed between the anode section and the cathode section, and an electrolyte. The method also includes disposing the plurality of core sections into a solvent so as to produce a mixture of cathode materials from the plurality of core sections. The solvent and the electrolyte form an ionic conductive medium, and the mixture of the cathode materials is characterized by a substantially homogeneous distribution of an active element in the cathode material.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims priority to U.S. Patent Application No. 62 / 772,243, filed on November 28, 2018, entitled "METHODS AND SYSTEMS FOR SCALABLE DIRECT RECYCLING OF BATTERIES", the disclosure of which is incorporated herein by reference in its entirety. (Technical Field)

[0002] The present disclosure generally relates to systems, devices, and methods for recycling energy storage devices, and more specifically to the recycling of lithium - ion batteries and their components.

Background Art

[0003] Lithium - ion batteries have high power and high energy density, long cycle life, high potential, and low self - discharge rate. As a result, they are generally regarded as the most promising approach for short - term energy storage and are widely used in consumer electronics, electric vehicles, and grid energy storage. However, lithium - ion batteries also have several drawbacks, including limitations in battery material supply, environmental risks during production or at the end of their service life, and high manufacturing costs.

Summary of the Invention

Means for Solving the Problems

[0004] Systems, apparatuses, and methods for recycling energy storage devices are disclosed. In some embodiments, the method includes processing at least one battery into a plurality of core segments. Each core segment in the plurality of core segments includes at least an anode segment including at least anode material, a cathode segment including at least cathode material, a separator segment disposed between the anode segment and the cathode segment, and an electrolyte. The method also includes placing the plurality of core segments in a solvent to produce a mixture of cathode material and other components from the plurality of core segments. The solvent and the electrolyte form an ion-conductive medium, and the mixture of cathode material is characterized by a substantially homogeneous distribution of active elements in the cathode material.

[0005] In some embodiments, the system includes a first device and a second device. The first device is configured to process at least one battery into a plurality of core segments, and each core segment in the plurality of core segments includes an anode segment, a cathode segment including cathode material, a separator segment disposed between the anode segment and the cathode segment, and an electrolyte. The second device is configured to receive the plurality of core segments and disperse or dissolve the plurality of core segments to produce a mixture of cathode material from the plurality of core segments. The solvent and the electrolyte form an ion-conductive medium, and the mixture of cathode material is characterized by a substantially homogeneous distribution of active elements in the cathode material.

[0006] In some embodiments, a method of recycling at least one battery includes cutting a plurality of lithium-ion batteries into a plurality of core segments. A first lithium-ion battery among the plurality of lithium-ion batteries has a first state of charge (SOC), and a second lithium-ion battery among the plurality of lithium-ion batteries has a second SOC different from the first SOC. Each core segment among the plurality of core segments includes an anode segment including an anode material, a cathode segment including a cathode material, a separator segment disposed between the anode segment and the cathode segment, and an electrolyte. The method also includes placing the plurality of core segments in a solvent to produce a mixture of the cathode material and the anode material from the plurality of core segments. The solvent and the electrolyte form an ion-conductive medium, and the mixture of the cathode material and the anode material includes a non-stoichiometric compound of an active element in the cathode material and is characterized by a substantially homogeneous distribution of the active element in the cathode material. The method further includes extracting the cathode material from the mixture of the cathode material and the anode material and re-lithiating the cathode material extracted from the mixture of the cathode material and the anode material to produce a battery-grade cathode material.

[0007] It is to be understood that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (assuming such concepts are not mutually inconsistent) are considered to be part of the subject matter of the invention disclosed herein. In particular, all combinations of the claimed subject matter found at the end of this disclosure are considered to be part of the subject matter of the invention disclosed herein. Also, it is to be understood that any terminology explicitly employed herein that also may be found in any disclosure incorporated by reference should be given a meaning most consistent with the particular concepts disclosed herein.

[0008] Other systems, processes, and features will become apparent to those of ordinary skill in the art upon review of the following drawings and detailed description. All such additional systems, processes, and features are intended to be included within this description, be within the scope of the invention, and be protected by the accompanying claims. This specification also provides, for example, the following items. (Item 1) A method, wherein the method comprises: Processing at least one battery into a plurality of core segments, wherein each core segment in the plurality of core segments comprises an anode segment, a cathode segment comprising a cathode material, a separator segment disposed between the anode segment and the cathode segment, and an electrolyte; Placing the plurality of core segments in a solvent to produce a mixture of cathode materials from the plurality of core segments; and the solvent and the electrolyte form an ion-conductive medium, and the mixture of the cathode materials is characterized by a substantially homogeneous distribution of active elements in the cathode materials. (Item 2) The at least one battery includes a lithium-ion battery, and the cathode material includes at least one of LiCoO, 2 LiMn, 2 O 4 LiFe, t M 1-t PO (LFMP), or LiNi, 4 where a + b + c + d = 1, and A = Al, Zr, or Mg. The method according to Item 1. a (Item 3) b Placing the plurality of core segments in the solvent includes placing the plurality of core segments in at least one of dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), or dimethylacetamide (DMAc). The method according to Item 2. c A d O 2 (Item 4) The at least one battery includes a first battery in a first state of charge and a second battery in a second state of charge different from the first state of charge. The method according to Item 1. (Item 5) The ion-conductive medium further includes conductive carbon from at least one anode segment in the plurality of core segments. The method according to Item 1. (Item 6) The method according to Item 1 further includes adding conductive carbon into the solvent to increase the electronic conductivity of the ion-conductive medium. (Item 7) The mixture of the cathode materials is produced without an electrochemical process. The method according to Item 1. (Item 8) The mixture of the cathode materials includes a lithium-deficient compound of the active element in the cathode material. The method according to Item 1. (Item 9) ​ ​ ​ The anode section in each core section contains an anode material, and the mixture of the cathode materials further contains the anode material from the plurality of core sections. The method according to item 1 further includes extracting the cathode material from the mixture of the cathode material and the anode material. (Item 10) The method according to item 9, wherein extracting the cathode material includes separating the cathode material from the anode material through a density-based separation process. (Item 11) The method according to item 9, wherein extracting the cathode material includes separating the cathode material from the anode material through a hydrophobicity-based separation process. (Item 12) The method according to item 9, wherein extracting the cathode material includes separating the cathode material through a filtration separation process based on the particle size of the cathode material. (Item 13) The method according to item 9, wherein extracting the cathode material includes separating the cathode material through an eddy current separation process. (Item 14) The method according to item 9, wherein extracting the cathode material includes separating the cathode material through a heat treatment process. (Item 15) The method according to item 1 further includes re-lithiating the cathode material extracted from the mixture of the cathode material and the anode material to produce a battery-grade cathode material. (Item 16) The method according to item 1 further includes deactivating the at least one battery before processing the at least one battery on the plurality of core sections. (Item 17) The method according to item 16, wherein deactivating the at least one battery includes contacting the at least one battery with a conductive powder and discharging the at least one battery. (Item 18) The method according to item 17, wherein the conductive powder includes at least one of a metal, carbon, or a conductive oxide. (Item 19) The method according to item 16, wherein deactivating the at least one battery includes contacting the at least one battery with a conductive fluid. (Item 20) The method according to item 1 further includes, after deactivating the at least one battery, using a conductive needle to pierce the at least one battery to estimate the discharged state of the at least one battery. (Item 21) The method according to item 1, further comprising delivering ultrasonic waves into the solvent to promote the production of the mixture of the cathode material. (Item 22) The method according to item 1, further comprising drying the plurality of core segments, heating to at least 400 degrees Celsius, to promote the production of the mixture of the cathode material. (Item 23) The method according to item 1, further comprising transferring the plurality of core segments to a second solvent to promote the production of the mixture of the cathode material. (Item 24) The method according to item 23, further comprising delivering ultrasonic waves into the second solvent to promote the production of the mixture of the cathode material. (Item 25) The at least one battery includes a plurality of batteries, and the method further comprises sorting the plurality of batteries into a group of first batteries having a first cathode material and a group of second batteries having a second cathode material, according to item 1. (Item 26) The method according to item 25, wherein sorting the plurality of batteries includes sorting the plurality of batteries using X-ray fluorescence. (Item 27) A system, the system comprising a first device configured to process at least one battery into a plurality of core segments, each core segment of the plurality of core segments comprising an anode segment, a cathode segment comprising a cathode material, a separator segment disposed between the anode segment and the cathode segment, and an electrolyte, the first device; a second device configured to receive the plurality of core segments, dissolve the plurality of core segments, and produce a mixture of cathode material from the plurality of core segments and comprising the solvent and the electrolyte form an ion-conductive medium, and the mixture of the cathode material is characterized by a substantially homogeneous distribution of active elements in the cathode material, the system. (Item 28) The first device is configured to process a lithium-ion battery, and the cathode material includes at least one of LiCoO 2 , LiMn 2 O 4 , LiFe t M 1-t PO 4 (LFMP), or LiNi a Mn b Co c A d O 2 , where a + b + c + d = 1 and A = Al, Zr, or Mg, according to item 27. (Item 29) The system according to item 27, wherein the second device is configured to hold at least one of dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), or dimethylacetamide (DMAc). (Item 30) The system according to item 27, wherein the second device is configured to produce the mixture of the cathode material without an electrochemical process. (Item 31) The system according to item 27, wherein the second device is configured to produce the mixture of the cathode material including a lithium-deficient compound of the active element in the cathode material. (Item 32) The system according to item 27, wherein the second device further comprises an ultrasonic transducer configured to deliver ultrasonic waves into the solvent to facilitate production of the mixture of the cathode material. (Item 33) The system according to item 27, further comprising a third device configured to heat the plurality of core sections to facilitate production of the mixture of the cathode material. (Item 34) The system according to item 27, further comprising a fourth device configured to receive the plurality of core sections, the fourth device comprising a solvent and an ultrasonic transducer, the ultrasonic transducer being configured to deliver ultrasonic waves into the solvent to facilitate production of the mixture of the cathode material. (Item 35) The anode section in each core section includes an anode material, the mixture of the cathode materials further includes the anode material from the plurality of core sections, and the system further comprises a third device configured to extract the cathode material from the mixture of the cathode material and the anode material. (Item 36) The system according to item 35, wherein the third device is configured to perform a density-based separation process to extract the cathode material from the mixture of the cathode material and the anode material. (Item 37) The system according to item 35, wherein the third device is configured to perform a hydrophobicity-based separation process to extract the cathode material from the mixture of the cathode material and the anode material. (Item 38) The system according to item 35, wherein the third device is configured to perform a filtration separation process to extract the cathode material from the mixture of the cathode material and the anode material. (Item 39) The system according to item 35, wherein the third device is configured to perform an eddy current separation process to extract the cathode material from the mixture of the cathode material and the anode material. (Item 40) The system according to item 27, further comprising a fourth device configured to re-lithiate the cathode material extracted from the mixture of the cathode material and the anode material to produce a battery-grade cathode material. (Item 41) The system according to item 27, further comprising a discharger configured to deactivate the at least one battery before the first device is configured to process the at least one battery into the plurality of core sections. (Item 42) The system according to item 27, wherein the discharger receives the at least one battery and includes a conductive powder for discharging the at least one battery. (Item 43) The system according to item 27, wherein the conductive powder includes at least one of a metal, carbon, a conductive oxide, or a fluid. (Item 44) The system according to item 27, further comprising a conductive needle configured to pierce the at least one battery after deactivating the at least one battery and estimate a discharged state of the at least one battery. (Item 45) A method of recycling at least one battery, the method comprising: Cutting a plurality of lithium-ion batteries into a plurality of core sections, wherein a first lithium-ion battery among the plurality of lithium-ion batteries has a first state of charge, and a second lithium-ion battery among the plurality of lithium-ion batteries has a second state of charge different from the first state of charge, and each core section among the plurality of core sections includes an anode section including an anode material, a cathode section including a cathode material, a separator section disposed between the anode section and the cathode section, and an electrolyte. placing the plurality of core segments in a solvent to produce a mixture of a cathode material and an anode material from the plurality of core segments, wherein the solvent and the electrolyte form an ion-conductive medium, and the mixture of the cathode material and the anode material comprises a non-stoichiometric compound of an active element in the cathode material and is characterized by a substantially homogeneous distribution of the active element in the cathode material; extracting the cathode material from the mixture of the cathode material and the anode material; re-lithiating the cathode material extracted from the mixture of the cathode material and the anode material to produce a battery-grade cathode material A method comprising the above steps.

Brief Description of the Drawings

[0009] One of ordinary skill in the art will understand that the drawings are primarily for illustrative purposes and are not intended to limit the scope of the subject matter of the invention described herein. The drawings are not necessarily to scale. In some instances, various aspects of the subject matter of the invention disclosed herein may be shown exaggerated or enlarged in the drawings to facilitate understanding of different features. In the drawings, like reference characters generally refer to like features (e.g., functionally similar and / or structurally similar elements).

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[0021] To address the drawbacks associated with lithium-ion batteries, the recycling of lithium-ion batteries can be employed to reduce the total life-cycle energy consumption, battery material demand, and manufacturing costs. For example, during battery production, wrought aluminum and cathode materials typically account for approximately half and 10% - 14% of the energy consumption or greenhouse gas (GHG) emissions, respectively, from raw material acquisition at the factory to product shipment. Recycling aluminum and cathode materials can thus significantly reduce the energy consumption and GHG emissions of battery production.

[0022] Battery recycling can be implemented through at least three approaches: smelting recycling, hydrometallurgical recycling, and direct recycling. In smelting battery recycling, end-of-life batteries are directly smelted from the bottom of a blast furnace to recover valuable metals such as Co, Ni, and Cu, typically in the form of alloys. An leaching process is usually carried out to separate the recovered metals.

[0023] Smelting can be employed to economically recover some elements (e.g., Co, Mn, Ni, etc.) from some types of cathode materials including LiCoO2, LiMn2O4, and LiNi x Mn y Co z O2 (x + y + z = 1). In some embodiments, any one of x, y, or z can be zero. However, since the metals recovered from LFMP batteries are not as valuable, through smelting, M = Mn, Ni, Co, V, or a metal element, or a combination of several metal elements (LFMP) cathodes, LiFe t M1-t Recycling PO4 is generally not economically advantageous. In addition, lithium and aluminum during refining usually end up as slag. Extensive and costly processing is typically done to separate the metals before they can be used to build new batteries. Furthermore, the refining process itself often generates extensive waste gases, thereby increasing the overall cost due to subsequent waste disposal.

[0024] The hydrometallurgical recycling process separates and / or isolates battery components before further processing. This approach is also applicable for recycling Ni-MH batteries. For lithium-ion batteries, lithium is ultimately recovered as Li2CO3, and other major materials such as Co, Ni, and Al can also be recovered. For Ni-MH batteries, rare earths and nickel can be recovered. Since hydrometallurgical recycling does not involve high temperatures and large volumes, such an approach changes the morphology of the battery cathode material, thereby making the cathode material unsuitable for reuse without further processing. Further information on hydrometallurgical recycling can be found in U.S. Patent No. 8,846,225, titled "Reintroduction of lithium into recycled battery materials" (incorporated herein by reference in its entirety).

[0025] Direct recycling of batteries can recover valuable cathode materials, as well as anode materials, current collectors, binders, and electrolytes, compared to the two approaches described above. The approach only includes low-temperature processes and can preserve the structure, morphology, and electrochemical properties of valuable materials. Some methods of direct recycling involve physically disassembling the battery into individual components before recovering the electrode materials. For example, the cathode, anode, and separator of the battery can be separated before the anode / cathode materials can be recovered via chemical treatment. Such physical separation of the battery is usually time-consuming and can make it difficult to recycle batteries on a large scale.

[0026] To increase the efficiency of direct recycling and extend direct recycling to an industrial level, the methods and systems described herein employ an expandable direct recycling technique that can recycle the battery without physically separating the cathode from the anode before electrode material recovery. In this technique, the battery is first processed into smaller pieces (also referred to as core segments), each containing an anode segment, a cathode segment, a separator, and an electrolyte. This process can be carried out on a large scale, for example, via a punching machine (see, e.g., FIGS. 4A-4D below).

[0027] The individual pieces are then chemically treated in a solvent, which can dissolve a binder that joins the electrode material to the corresponding current collector and produces a mixture of cathode material (usually also including anode material from the core section) from the core section. The solvent and electrolyte also form an ion-conductive medium, which can facilitate the transport of active elements (such as lithium, protons, and / or hydroxyl) in the cathode material within the mixture. This transport can substantially homogenize the distribution of the active elements in the cathode material. The cathode material from the chemical treatment is typically deficient in the ratio of active elements (e.g., lithium-deficient). However, such deficiencies do not affect the overall efficiency of the recycling technique because, as long as the distribution of the active elements is uniform in the cathode material, further treatment (e.g., relithiation) can be easily carried out to replenish the active elements and produce a battery-grade cathode material.

[0028] Since each step in the techniques described herein can be easily scaled up, the entire recycling process can also be implemented on a large scale. In addition, the transport of active elements during chemical treatment enables the simultaneous recycling of batteries in different charge states, thereby avoiding the costly and time-consuming steps of determining the charge state in some other recycling techniques.

[0029] FIG. 1 is a flowchart illustrating a method 100 for recycling the cathode material of a battery according to some embodiments. Typically, the cost of a battery is determined by the cost of the battery component materials (e.g., more than about 50%), which is in turn determined by the cost of the cathode material. For example, the cathode material in a battery can be about two to four times more expensive than the other component elements in the same battery. Therefore, recycling the cathode material via method 100 can make a significant contribution to cost savings.

[0030] Method 100 includes, at 110, processing one or more batteries into a plurality of core segments each including an anode segment, a cathode segment including a cathode material, a separator segment disposed between the anode segment and the cathode segment, and an electrolyte. Each core segment can also include a current collector segment such as a first current collector segment coupled to the anode segment and a second current collector segment coupled to the cathode segment. In other words, the processing at 110 converts each battery component (e.g., anode, cathode, separator, and current collector) into a plurality of pieces.

[0031] In some embodiments, each core segment includes one anode segment and one cathode segment. In some embodiments, each core segment can include a plurality of anode segments and a plurality of cathode segments. For example, the battery can have a jelly roll structure, and the processing at 110 can cut the battery perpendicular to the sidewall of the cylinder (see, e.g., FIG. 5A). As a result, each core segment from the processing at 110 also includes a jelly roll having a plurality of layers of anode and cathode. In another example, the battery can have a prismatic structure including a stack of battery cells, and each stack includes an anode, a cathode, and a separator (see, e.g., FIG. 5B). The processing at 110 can cut the battery along the depth of the stack, thereby producing core segments including a plurality of layers of anode / cathode / separator combinations. Thus, method 100 can be implemented regardless of the structure of the battery and demonstrate greater flexibility in practice.

[0032] In some embodiments, the cathode section and / or the anode section include at least one of an active material, a conductive material (e.g., conductive carbon), a binder, and a current collector. In some embodiments, each core section can include at least one of an anode section, a cathode section, a separator, or an electrolyte. In some embodiments, each core section can include only the cathode section. In some embodiments, each core section can include only the anode section. In some embodiments, each core section can include only (1) an electrolyte and (2) either a cathode section or an anode section. In some embodiments, each core section can include only (1) an electrolyte, (2) a separator, and (3) either a cathode section or an anode section. In some embodiments, each core section can additionally include battery packaging material.

[0033] In some embodiments, the process at 110 includes deforming at least one battery to facilitate cutting of the at least one battery into a plurality of core sections prior to cutting the at least one battery. For example, a battery with a jelly roll structure can be compressed in the cutting direction prior to cutting to create a deformed battery. The thickness of the battery deformed in the cutting direction can be similar to the thickness of a prismatic battery of a similar size. As a result, the similar thickness in the cutting direction for each battery facilitates simultaneous cutting of the plurality of batteries, thereby improving processing efficiency.

[0034] Method 100 also includes, at 120, placing the core section in a solvent to produce a mixture of cathode materials from the core section, i.e., cathode materials from different core sections are mixed together to form a mixture. The mixture can also include other materials such as anode materials, binders, separators, and current collectors. However, for illustrative purposes, the description herein focuses on the cathode material. Further details regarding separating the cathode material from other materials can be found below with reference to FIGS. 6 and 7. The solvent and electrolyte form an ion-conductive medium, and the mixture of cathode materials is characterized by a substantially homogeneous distribution of active elements (or their ions) in the cathode material due to the transport of active elements in the mixture facilitated by the ion-conductive medium. In some embodiments, the ion-conductive medium is also conductive to electrons.

[0035] Method 100 can be implemented to recover various types of cathode materials. In some embodiments, the cathode material can include cobalt-rich materials such as LiCoO2. In some embodiments, the cathode material is LiNi x Mn y Co z O2 (where x + y + z = 1), or in a more general form, LiNi a Mn b Co c A d O2 (where A = Al, Zr, Mg, etc. and a + b + c + d = 1), and can include nickel-rich materials. In some embodiments, the cathode material can include an L-M-O system such as LiMn y O4. In some embodiments, the cathode material can include LiFe t M 1-t PO4.

[0036] In some embodiments, the cathode material can include a first material coated by a second material. For example, the cathode material can include LiCoO2 coated with Al2O3. In some embodiments, the cathode material can include a first material (also referred to as a host material) doped with a second material (also referred to as a dopant). For example, the cathode material can include LiMn 2-x Al x O 4-y and can include. Any other suitable cathode material known in the art can also be used herein.

[0037] In some embodiments, the cathode of the battery is made from any of the cathode materials described herein and includes a film mixed with carbon and a binder (e.g., polyvinylidene fluoride or PVDF). The film can then be disposed on a current collector (e.g., aluminum or copper). In a battery that has reached the end of its service life, the cathode material may have depleted active elements (e.g., lithium). Using LiCoO2 as an example, the cathode material can be represented as Li x CoO2 (where x is less than 1 (i.e., x < 1)). In another example, the cathode material can include LiNi a Mn b Co c A d O2 (where A = Al, Zr, Mg, etc. and a + b + c + d = 1) and can include. In a battery that has reached the end of its service life, the cathode material can be represented as Li x Ni a Mn b Co c A d O2 (where x is less than 1).

[0038] The anode material of the anode section within the battery can also have various options. In some embodiments, the anode material includes graphite. In some embodiments, the anode material includes tin, tin-cobalt alloy, silicon, or silicon oxide. In some embodiments, the anode material includes Li4Ti5O 12 including. In some embodiments, the anode of the battery can be formed from graphite mixed with a binder (e.g., PVDF) and disposed on an anode current collector (e.g., copper or aluminum).

[0039] In some embodiments, the electrolyte within the battery can include a lithium-based salt in an organic solvent. The lithium-based salt can be, for example, LiPF6. The organic solvent can include, for example, ethylene carbonate (EC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), propylene carbonate (PC), and / or combinations thereof.

[0040] The solvent used in method 100 is configured to dissolve the binder within the electrodes (including the cathode and anode), and further configured to form an ion-conductive medium into an electrolyte. In some embodiments, the solvent can include a polar solvent capable of dissolving a binder such as PVDF. Examples of such polar solvents can include, among others, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), and dimethylacetamide (DMAc). In some embodiments, the solvent can include water capable of dissolving a water-soluble binder. Examples of such binders can include, among others, poly(ethylene oxide) (PEO) and carboxymethyl cellulose (CMC).

[0041] One or more batteries in step 110 of method 100 can be processed into a plurality of core segments via various techniques. In some embodiments, a punching machine can be employed to cut the battery into pieces (see, for example, FIGS. 4A-4D). In some embodiments, the battery can be cut via a laser cutter. In some embodiments, the battery can be cut via a water jet cutter.

[0042] In some embodiments, the processing in 110 is performed using a rotary cutting wheel. In some embodiments, the processing in 110 is performed using a fly knife or a saw blade, which moves along a direction perpendicular to the depth of the stack of each core segment.

[0043] Each battery to be recycled via method 100 can be processed into any suitable number of core segments. On the one hand, increasing the number of core segments produced from each battery can increase the contact area between each core segment and the solvent (or the ratio of contact area to volume). On the other hand, cutting the battery into too many pieces can introduce undesirable debris and impurities. The number of core segments produced from each battery can also depend on the dimensions of the battery (for example, a larger number of core segments can be produced from a larger battery). In some embodiments, the number of core segments produced from each battery can be from about 2 to about 50 (for example, about 2, about 3, about 5, about 10, about 20, about 30, about 40, or about 50, including any value and sub-range therebetween).

[0044] The cathode material produced from step 120 in method 100 is characterized by a substantially homogeneous distribution of active elements. As used herein, a substantially homogeneous distribution of active elements refers to a situation where the atomic ratios of the active elements in the compounds forming the cathode material are substantially the same. For example, the cathode material is Li xIt can contain CoO2, where (x is equal to 1) (for example, fully lithiated) or less than 1 (i.e., lithium-deficient), and Li in the cathode material produced after step 120 x Different molecules of CoO2 have substantially the same x.

[0045] In some embodiments, the homogeneous distribution of the active elements can be characterized by the standard deviation of the atomic ratio distribution. For example, the cathode material can contain Li x CoO2, and the standard deviation of x can be substantially equal to or less than 0.1 (e.g., about 0.1, about 0.09, about 0.08, about 0.07, about 0.06, about 0.05, or less, including any value and sub-range therebetween). In some embodiments, the average value of x can be denoted as x0, and x in each Li x CoO2 molecule can be within about 10% (about 10%, about 9%, about 8%, about 7%, about 6%, about 5%, about 4%, about 3%, about 2%, about 1%, or less, including any value and sub-range therebetween) of x0, i.e., 0.9x0 to 1.1x0, so as to form a homogeneous distribution of the active elements. The above definitions can similarly be applied to any other cathode material described herein.

[0046] To experimentally estimate the distribution of the active elements in the cathode material, at least two methods can be employed. In some embodiments, the cathode material at different locations in the mixture is sampled and characterized, for example, using inductively coupled plasma atomic emission spectroscopy (ICP-AES) to measure the atomic ratio of the active elements. In some embodiments, X-ray tomography can be employed to measure the active element homogeneity of individual particles at the microscale.

[0047] In some embodiments, method 100 can be employed to batch recycle batteries having different states of charge. For example, the batteries can include a first battery in a first state of charge and a second battery having a second state of charge. After step 120, the cathode materials from these different batteries are mixed together to form a mixture, and the transport process occurring during step 120 can substantially homogenize the distribution of the active element (e.g., Li). The cathode material after step 120 can then be re-lithiated to form a battery-grade cathode material.

[0048] In some embodiments, method 100 can be employed to batch process batteries having different deficiencies in the active element. For example, the batteries can include a first battery having a first cathode material represented as Li x1 CoO2 and a second battery having a second cathode material represented as Li x2 CoO2 (where x1 is different from x2). Method 100 can result in a mixture of the first and second cathode materials having a homogeneous distribution of lithium (e.g., Li x3 CoO2 where x3 is different from x1 and x2), and the cathode material can be prepared for subsequent re-lithiation.

[0049] In some embodiments, the heterogeneity of the active element can occur within a single battery prior to recycling. In these cases, the cathode materials from different core segments can have different deficiencies in the active element, and method 100 can substantially homogenize the active element distribution and prepare the cathode material for subsequent re-lithiation.

[0050] In some embodiments, the transport of the active element during step 120 can be improved by one or more additives in an ion-conductive medium formed by a solvent and an electrolyte. In some embodiments, the additive can include conductive carbon from the anode section of the core section. In these cases, the anode section can include graphite. In some embodiments, the additive can include conductive carbon added into the solvent. For example, carbon powder can be added to the solvent to increase the conductivity of the resulting ion-conductive medium. In some embodiments, the additive can include a lithium salt added to the solvent to improve the ionic conductivity of the medium.

[0051] In some embodiments, the transport of the active element during step 120 can be improved by ultrasonic mixing. In these cases, an ultrasonic transducer can be employed to deliver ultrasonic waves into a container containing the ion-conductive medium so as to increase the transport efficiency.

[0052] In some embodiments, method 100 can further include agitating the ion-conductive medium. In one example, a rocking platform can be employed to hold a container containing the ion-conductive medium and cause a rocking motion to the container so as to increase the transport efficiency. In another example, one or more impellers or blades can be coupled to a container containing the ion-conductive medium and configured to agitate the ion-conductive medium.

[0053] In some embodiments, method 100 can further include increasing the temperature of the ion-conductive medium so as to increase transport efficiency. For example, a heater can be coupled to a container containing the ion-conductive medium to heat the ion-conductive medium. In some embodiments, any combination of the techniques for improving transport efficiency described herein can be employed. In some embodiments, method 100 can further include removing and replenishing the solvent to control the concentrations of electrolyte, anode material, cathode material, and contaminants (e.g., dissolved electrode binder).

[0054] In some embodiments, method 100 can be implemented without an electrochemical process. As used herein, an electrochemical process refers to a process that is caused by or associated with the passage of an electric current and involves the transfer of electrons between two substances. In these cases, method 100 is employed to prepare cathode materials having a homogeneous distribution of active elements, and these cathode materials can be further replenished with active elements on a large scale.

[0055] In some embodiments, the mixture of cathode materials further includes other components such as anode material, current collector, and separator. In these cases, the cathode material can be extracted from the mixture for further processing (e.g., relithiation). In some embodiments, the cathode material (e.g., a lithium-containing compound) and the anode material (e.g., a carbon-based material such as graphite) have different densities, and thus they can be separated from each other using a density-based separation process (e.g., centrifugation). For example, the anode active material can include graphite having a density of about 2 g / cc, and the cathode material can include a metal oxide having a density of about 4-5 g / cc. Such density differences enable the density-based separation process to yield a cathode active material that is uniform but has a non-stoichiometric amount of lithium.

[0056] In some embodiments, the separation of the cathode material from other components comprises a filtration technique. In these cases, the cathode material has a different particle size than some of the other components. For example, the filtration technique can include one or more screening steps using one or more sieves of different pore sizes. In some embodiments, the filtration technique includes the use of an ultrasonic transducer to break up the aggregation of particles. In some embodiments, the ultrasonic transducer is used to separate the cathode material from other components of the mixture. For example, the cathode material can be physically separated from the current collector or separator using such an ultrasonic transducer. The current collector, separator, or other larger pieces can be filtered using a basket or other filtration device.

[0057] In some embodiments, the separation process of the cathode material can be carried out in a solvent. In some embodiments, the solvent is water. In other embodiments, the solvent is an organic solvent including, but not limited to, DMF, NMP, ethanol, methanol, isopropanol, acetone, EC, DMC, EMC, DEC, and PC. In some embodiments, an additive can be added to facilitate the separation process. In some embodiments, the additive changes the pH of the solution. In some embodiments, the additive raises the pH of the solution. In some embodiments, the additive is LiOH, NaOH, or a similar additive. In some embodiments, the solvent can be heated to increase the rate or effectiveness of the separation.

[0058] In some embodiments, the separation process of the cathode material includes a dissolution technique. Certain components in the mixture of the cathode material, anode material, current collector, electrolyte, and / or separator may preferentially dissolve in a solvent. These components can be dissolved and separated from the rest of the mixture. For example, a solution of ammonia can be used to dissolve and remove Cu and / or Al current collectors or other components from the mixture. In another example, a solution of LiOH, NaOH, or a similar additive in water can be used to separate Al current collectors or other components from the mixture. In some embodiments, the mixture can be heated to increase the rate or effectiveness of separation.

[0059] In some embodiments, the separation of the cathode material from other components can be performed via a hydrophobic separation technique (also referred to as flotation separation or froth flotation). Flotation separation uses a solvent (e.g., a polar solvent such as water) mixed with a promoter (e.g., kerosene) that promotes the hydrophobicity of other materials and a foaming agent (e.g., long-chain alcohols, 4-methyl-2-pentanol, pine oil). The promoter preferentially binds to components that are hydrophobic. The solvent is aerated to produce a foam mainly composed of the promoter, foaming agent, and hydrophobic components. The foam is separated from the solution via scraping or other surface collection mechanisms. The hydrophilic components are then separately collected from the solution. In these cases, the cathode material has a different level of hydrophobicity from some of the other components. For example, cathode materials such as LiCoO2 tend to be hydrophilic, while some anode materials such as graphite tend to be hydrophobic. Thus, the anode material can be removed from the foam, and the cathode material can be collected from the solution in the lower layer of the foam. In some embodiments, other additives such as pH adjusters (e.g., sodium carbonate, sodium hydroxide, lithium carbonate, and lithium hydroxide), peptizing agents, and inhibitors (used to increase the hydrophilicity of a certain compound, e.g., lime, sodium cyanide, and dextrin) can also be used to further promote the separation.

[0060] In some embodiments, the separation of the cathode material from other components can be performed via a heating technique. The heating technique (also referred to as heat treatment) involves heating the mixture of the cathode material and other components to a temperature so as to facilitate the decomposition or vaporization of certain components of the mixture. In some embodiments, the decomposition of a component is into one or more gaseous compounds. For example, heating the mixture to a temperature above a certain temperature (e.g., 400 degrees Celsius) can decompose or vaporize a binder (e.g., PVDF), an electrolyte (e.g., EC, DMC, EMC, DEC, and PC), a solvent (such as those solvents used in step 120 of other separation processes or methods 100), and / or a separator (e.g., polyethylene or polypropylene). Such decomposition or vaporization can form gaseous compounds, which can be separated from the liquid mixture. In some embodiments, the mixture is heated to a temperature of about 400, 500, 600, 700, or 800 degrees Celsius or higher. In some embodiments, the mixture is heated in air. In some embodiments, the mixture is heated in a relatively inert or neutral atmosphere (e.g., N2, Ar, He, etc.). In some embodiments, the mixture is heated in a reducing atmosphere (e.g., CO / CO2, H2 in N2, Ar, or H2O).

[0061] In some embodiments, the separation of the cathode material from other components can be performed via an eddy current technique. The eddy current technique uses a transport system that transports the mixture of the cathode material and other components to one or more rotating magnetic materials. The rotating magnetic materials create an induced field that magnetizes the mixture of the cathode material and other components to different magnetization levels. The mixture of the cathode material and other components is then ejected to different locations by a strong magnet that attracts or repels different components to different extents depending on the ratio of the components of electronic conductivity and density. In these cases, the cathode material has a different ratio of electronic conductivity and density from other components and is thus ejected to a location separate from the location of other components.

[0062] In some embodiments, method 100 can further include deactivating the batteries before processing them into a plurality of core segments. In some embodiments, deactivation can be performed by placing the batteries in a conductive powder such that both the positive and negative electrodes of each battery are in electrical contact with the conductive powder (see, for example, FIG. 3A below). In some embodiments, deactivation can be performed by placing the batteries in a conductive fluid such that both the positive and negative electrodes of each battery are in electrical contact with the conductive fluid. As a result, the batteries are discharged. In some embodiments, the conductive fluid can include a conductive powder and a solvent. In some embodiments, the conductive powder can be suspended in the solvent during use. The conductive powder can include, for example, carbon, metal, conductive oxide, or any other suitable conductive material. The solvent can include, for example, silicone oil, cooking oil, ethylene glycol, or any other suitable solvent.

[0063] In some embodiments, the solvent includes water. In some embodiments, additives such as buffers or other pH-adjusting additives can be added to the aqueous solvent. The additives can increase the pH of the aqueous solvent and inhibit corrosion. Additionally, the basicity of the solvent can neutralize acidic or acid-forming compounds that may be released by the batteries. In some embodiments, the batteries can be completely submerged in the conductive powder or slurry.

[0064] The discharge rate usually depends on the conductivity (or resistivity) of the conductive powder. Thus, different conductive powders can be used to adjust the discharge rate. In some embodiments, the conductive powder includes metals (such as aluminum powder, iron powder, copper powder, stainless steel powder, etc.). In some embodiments, the conductive powder includes carbon (such as graphite powder, carbon black nano powder, or carbon nanotubes, etc.). In some embodiments, the conductive powder includes conductive oxides (such as indium tin oxide (ITO), ZnO, In2O3, SnO2, nickel oxide, and manganese oxide, etc.). In some embodiments, the properties of the conductive powder (such as conductivity or packing density) can be modified to adjust conductivity by incorporation of non-conductive or conductive liquids. In some embodiments, the conductive powder can include any combination of the materials described herein.

[0065] In some embodiments, the conductive powder can be further modified to increase its affinity with the solvent being used. For example, in an aqueous solvent, a carbon-based conductive powder can be oxidized or polarized to form a less hydrophobic compound that disperses more uniformly in the aqueous solvent. This more uniform distribution of the conductive powder can increase the conductivity of the solution.

[0066] In some embodiments, deactivation is performed using the conductive fluids described herein. In these cases, the conductivity of the conductive fluid (and following the discharge rate) can be adjusted by the viscosity, the concentration of the conductive powder in the conductive fluid, and / or the solvent material. For example, the electronic conductivity can increase with an increase in viscosity until it reaches a plateau. The ionic conductivity can also increase with an increase in viscosity until it reaches a deflection point where the ionic conductivity then begins to decrease.

[0067] In some embodiments, method 100 can further include estimating the state of discharge of the battery before processing the battery into a plurality of core segments. In some embodiments, the estimation is performed to determine whether the battery is fully discharged so as to enable safe disassembly in step 110 of method 100. In these cases, conductive nails can be employed to pierce through the battery (see, e.g., FIG. 3B below). If the battery passes such a test (e.g., without smoke or fire), the battery is then processed into a plurality of core segments. However, if the battery fails the test, the battery can be placed in salt water and further discharged for hazard control.

[0068] In some embodiments, the estimation of the state of discharge is performed using a voltage measurement technique. In some embodiments, the voltage measurement technique includes the installation of conductive probes throughout the discharge medium. The state of discharge of the battery can be estimated from the voltages measured at each probe using finite element analysis or other suitable methods. In other embodiments, the voltage measurement technique comprises a non-contact voltage scanning tool for estimating the state of discharge of the battery.

[0069] In some embodiments, the estimation of the state of discharge is performed using a current measurement technique. The change in the state of discharge can be correlated with the current. In some embodiments, a Hall effect sensor is used to estimate the state of discharge.

[0070] The above description of method 100 uses a lithium-ion battery as an example mainly for illustrative purposes only. In practice, method 100 can be employed to recycle any other suitable type of energy storage device. For example, method 100 can be employed to recycle capacitors including lithium-ion capacitors and supercapacitors (also referred to as ultracapacitors).

[0071] Figure 2 is a flowchart illustrating a method 200 for expandable direct recycling of batteries according to some embodiments. Method 200 includes, at 210, deactivating a battery (e.g., a battery that has reached the end of its useful life and / or a defective battery product) to ensure safety during subsequent processing of the battery. Deactivation can be achieved by short-circuiting the battery and completely discharging the battery (e.g., using a conductive powder or fluid as described herein). With respect to battery component waste (e.g., defective electrode sheets, residual slurry), recycling of these wastes can start from 220 or 230.

[0072] Before or after 210, the batteries can be sorted by cathode material using an elemental analysis tool (e.g., X-ray fluorescence). The elements in the cathode material can be identified with or without removing the pouch cover. Batteries with the same cathode material can be grouped together for further processing.

[0073] Method 200 also includes, at 220, physically disassembling the battery. In some embodiments, the battery includes prismatic battery cells, and the pouches of these cells are cut and removed at 220. In some embodiments, the battery includes cylindrical cells, and the cases of these batteries are cut and removed at 220. Additionally, each battery is also processed into a plurality of core sections, and such processing can be substantially similar to step 110 in method 100 described herein. In some embodiments, each core section includes at least an anode section, a cathode section, and a separator disposed therebetween. The output of step 220 includes (1) the pouch and / or case material that is collected, and (2) the core sections for subsequent processing.

[0074] The core fraction from 220 is then processed at 230, which includes chemical treatment and separation. In this step, the core fraction is placed in a solvent that dissolves the binder of the electrode resulting from a mixture of the current collector, cathode material, anode material, electrolyte, and separator. The active elements of the cathode material are substantially homogenized during 230 (similar to step 120 in method 100 described herein). The homogenized cathode material can be extracted via a centrifugation process. Metal parts (e.g., Al or Cu current collectors), separators, and electrolytes can also be separated and recycled. Further details of the chemical treatment and separation process are provided below with reference to FIGS. 6 and 7.

[0075] At 240, the cathode material is processed to produce a battery-grade cathode material. As described herein, the cathode material produced from 230 typically lacks active elements, and the material treatment at 240 is employed to replenish the active elements. For example, with respect to a lithium-ion battery, the material treatment 240 can re-lithiate the cathode material. Further details of the material treatment are provided below (see, e.g., FIGS. 10A-10B).

[0076] FIGS. 3A-3B illustrate, respectively, battery deactivation and state-of-charge estimation according to several embodiments. FIG. 3A illustrates a method 300 for deactivating a battery 330. In method 300, two tabs 335a and 335b of the battery (also referred to as two conductive wires 335a and 335b) electrically coupled to the positive and negative electrodes are each placed in a conductive powder 320 contained within a container 310. The conductive powder 320 is configured to short-circuit the battery 330 so as to fully discharge the battery 330, thereby ensuring safety during subsequent processing of the battery 330.

[0077] The discharge rate in method 300 may depend on the resistance (or conductivity) of the conductive powder 320. In practice, the resistance of the conductive powder 320 can be adjusted by the selection of the powder material and / or the powder particle size. In other words, the use of different powder materials and / or powder particle sizes can control the discharge rate of the battery 330.

[0078] In some embodiments, the conductive powder includes a metal (e.g., aluminum powder, iron powder, copper powder, stainless steel powder, etc.). In some embodiments, the conductive powder includes carbon (e.g., graphite powder, carbon black nano powder, or carbon nanotubes, etc.). In some embodiments, the conductive powder includes a conductive oxide (e.g., indium tin oxide (ITO), ZnO, In2O3, SnO2, nickel oxide, and manganese oxide, etc.).

[0079] The particle size of the conductive powder 320 can be, for example, from about 200 nm to about 1 cm (e.g., about 200 nm, about 300 nm, about 500 nm, about 1 μm, about 2 μm, about 3 μm, about 5 μm, about 10 μm, about 20 μm, about 30 μm, about 50 μm, about 100 μm, about 200 μm, about 300 μm, about 500 μm, about 1 mm, about 2 mm, about 3 mm, about 5 mm, or about 1 cm, including any value and sub-range therebetween).

[0080] FIG. 3A shows that the battery 330 has a prismatic configuration for illustrative purposes only. In some embodiments, the battery 330 can have any other suitable configuration, such as a cylindrical configuration. In these cases, the entire battery 330 can be immersed in the conductive powder 320 such that the two electrodes of the battery 330 are electrically connected to each other via the conductive powder 320. In some embodiments, method 300 can use a conductive fluid as described in the specification instead of or in addition to the conductive powder 320 for this non-activation.

[0081] Figure 3B illustrates a method 301 for testing the discharge state of the battery 330. In method 301, a conductive needle 350 is employed to puncture through the battery 330 such that it makes electrical contact with both electrodes of the battery 330. In some embodiments, the conductive needle 350 can be replaced by a nail or any other suitable tool. This puncturing process can be employed as a safety assurance and quality control for the deactivation method 300 illustrated in Figure 3A. In some embodiments, a smoke detector or a gas sensor is employed to detect smoke and gas respectively during method 301. If the battery 330 fails during deactivation 300 and / or the discharge state test 301 (e.g., the battery 330 catches fire), the failed battery 300 is immediately immersed in a liquid (e.g., salt water) to prevent fire or smoke.

[0082] Figures 4A - 4D illustrate a method 400 for processing a battery 470 into a plurality of core segments 475 according to some embodiments. Method 400 is implemented using an apparatus 401, which includes a die 410 coupled to a base 430 via two springs 420, and a punch 440 (also referred to as a cutter 440 or a blade 440) that is movable along two induction posts 450 (also referred to as induction struts 450). The battery 470 is placed on a holder 460 for processing. In some embodiments, the pouch or case of the battery 470 is removed before the battery 470 is placed on the holder 460.

[0083] Figure 4A shows the battery 470 being advanced towards the die 410 such that at least a portion of the battery 470 is directly above the die 410. In this step, the die 410 is opened and the springs 420 are extended (i.e., not compressed). In some embodiments, the battery 470 can be manually advanced towards the die 410. In some embodiments, a conveyor or a pusher (not shown in Figure 4A) can be employed to place the battery 470 under the punch 440.

[0084] Figure 4B shows that the punch 440 is pressed against the battery 470 by moving downward along the guide post 450 so as to cut the battery 470. In some embodiments, the punch 440 can be manually pressed against the battery 470. In some embodiments, a motor (not shown in FIG. 4A) can be employed to control the movement of the punch 440. In some embodiments, a pusher can be employed to push the battery 470 for the punch and gradually advance the battery 470. In this step, the die 410 is closed and the spring 420 is compressed.

[0085] In FIG. 4C, the punch 440 is raised and a portion of the battery 470 directly below the punch 440 is cut into a plurality of core segments 475. Five core segments 475 arranged in a sequence are illustrated in FIG. 4C. In some embodiments, the punch 440 and the die 410 can be configured to cut the battery 470 into any other number of core segments in one punch. In some embodiments, the punch 440 and the die 410 can be configured to cut the battery 470 into a two-dimensional (2D) array of core segments 475.

[0086] In FIG. 4D, the battery 475 is advanced again to allow collection of the core segments 475 produced during the previous punch. Additionally, the advancement also positions a new portion of the battery 470 under the punch 440 for another step of the process. This process can continue until substantially the entire battery 470 has been processed into core segments.

[0087] In FIGS. 4A-4D, only one battery 470 is shown for illustrative purposes only. In some embodiments, battery 470 can include a plurality of batteries. Punch 440 and die 410 can be configured to cut a plurality of batteries 470 into a 2D array of core sections 475. In some embodiments, core section 475 can be removed via the method described in FIG. 4D. In some embodiments, holder 460 has an orifice that can be opened to release core section 475 to a separate location after cutting.

[0088] FIGS. 5A-5C show a schematic of a battery that can be processed into a plurality of core sections via the method illustrated in FIGS. 4A-4D, according to some embodiments. FIG. 5A shows a schematic of a battery 501 having a cylindrical configuration. Battery 501 includes at least an anode 511, a cathode 521, and a separator 531 disposed therebetween. The stack of anode 511, cathode 521, and separator 531 is then wound into a jelly roll contained within a case 541 (usually a metal case), thereby resulting in a cylindrical configuration. Method 400 can be implemented to cut battery 501 along line AA, or line A'A', or both, as illustrated in FIG. 5A, and each resulting core section can include a shortened jelly roll that includes multiple windings of the cathode, anode, and separator.

[0089] Figure 5B shows an overview of a battery 502 having a prismatic case configuration. The battery 502 includes a cathode 512, an anode 522, and a separator 532 disposed therebetween. The cathode 512, anode 522, and separator 532 are stacked together and contained within a case 542 (usually a metal case), thereby forming a sheet structure that forms a prismatic case configuration. The method 400 can be implemented to cut the battery 502 along line BB, or line B'B', or either of both, as illustrated in Figure 5B. In some embodiments, the battery 502 can include a multi-stack structure, and each stack includes a cathode, an anode, and a separator. As a result, each core segment produced by the method 400 includes a plurality of cathode segments, anode segments, and separator segments. In some embodiments, the batteries 501 and 502 illustrated in Figures 5A - 5B can have at least one end cut open to expose a battery core that can be pushed out for further processing (e.g., punching).

[0090] Figure 5C shows an overview of a battery 503 having a prismatic pouch configuration. The battery 503 includes a cathode 513, an anode 523, and a separator 533 disposed therebetween. The cathode 513, anode 523, and separator 533 are stacked together and contained within a pouch 543 (usually a metal foil), thereby forming a sheet structure that forms a prismatic pouch configuration. The method 400 can be implemented to cut the battery 503 along line CC, or line C'C', or either of both, as illustrated in Figure 5C. In some embodiments, the battery 503 can include a multi-stack structure, and each stack includes a cathode, an anode, and a separator. As a result, each core segment produced by the method 400 includes a plurality of cathode segments, anode segments, and separator segments.

[0091] The cut lines AA, A’A’, BB, B’B’, CC, and C’C’ as shown in FIGS. 5A - 5C are substantially parallel to at least one edge of the batteries 501 - 503. In some embodiments, any other suitable cut lines can also be used. For example, the cuts of batteries 502 and 503 can occur along the diagonal of the case / pouch.

[0092] FIG. 6 is a flowchart illustrating a method of chemical treatment and separation in the direct recycling of batteries, according to some embodiments. Method 600 includes, at 610, ultrasonic cleaning of the core sections produced from the batteries. Each core section includes at least one anode / cathode / separator assembly. The core sections are placed in a solvent that dissolves the binder, electrolyte solvent, and electrolyte salts. In this step, the core sections are separated into individual components including the cathode / anode material (usually in particulate form), separator pieces, and current collector pieces. These components are mixed together in a mixture.

[0093] Method 600 also includes, at 620, extracting the mixture of anode and cathode materials via a multi - step washing process within a separation device (e.g., a filter - mixer - dryer (FMD) and / or a centrifuge type device such as a batch centrifuge or a continuously operating decanter). In other words, during this step, the mixture of anode and cathode materials is separated from the other components in the mixture produced at 610. The mixture of anode and cathode materials is then put out for re - lithiation, while the remaining components (e.g., binder, electrolyte salts, etc.) undergo further separation.

[0094] In 630, a distillation column is used to separate the components of the effluent from the multi-step wash 620 according to their individual boiling points. As the effluent progresses downward through the distillation column, the components are vaporized and subsequently condensed (at 640) by one or more condensers operating at an appropriate condensation temperature. The condenser is configured to extract an electrolyte solvent (e.g., DMC), which is then collected for transfer to a solvent recovery company outside the facility. At least one condenser that can be incorporated within a solvent recovery system (e.g., see step 660) operates at an appropriate temperature to condense the wash solvent water vapor exiting the distillation column. The wash solvent condensed from this condenser is combined with solvents recovered from other operations (e.g., drying) and returned to the primary wash process (e.g., 620). The liquid effluent from the bottom of the distillation column (e.g., from step 630) is vaporized in an evaporator (at 650), and the water vapor progresses upward through the distillation column, heating the column and providing the water vapor to individual condensers. Solvents with high boiling points (e.g., EC and PC) are released from the evaporator into the waste stream along with solids (e.g., LiPF6, PVDF, and CMC).

[0095] FIG. 7 illustrates a system 700 for chemical treatment and separation during direct recycling of a battery according to some embodiments. The chemical treatment and separation process further includes three separation processes (i.e., a first separation process, a second separation process, and a third separation process) and one solvent recovery process that can be implemented in either a batch configuration or a continuous flow configuration, respectively.

[0096] System 700 includes a cleaning facility 712 for receiving a core section of a battery (e.g., produced by method 400 illustrated in FIGS. 4A - 4D). In some embodiments, the cleaning facility 712 includes a metal wire basket. In some embodiments, the cleaning facility 712 includes a perforated basket. Any other suitable facility can also be used. In some embodiments, each core section includes a plurality of layers of an anode sheet (i.e., a copper current collector, an active anode material, and an anode binder), an electrolyte-filled separator, and a cathode sheet (i.e., an aluminum current collector, an active cathode material, and a cathode binder).

[0097] System 700 also includes an ultrasonic cleaner 714 for receiving the cleaning facility 712 into which the core sections are loaded. The ultrasonic cleaner 714 is configured to contain a cleaning solvent (e.g., an organic solvent such as N-methyl-2-pyrrolidone, NMP, or an aqueous solution) (also referred to herein as the cleaning solvent). In some embodiments, the ultrasonic cleaner 714 defines a headspace above the cleaning solvent, and the headspace can be filled with an inert gas (e.g., nitrogen).

[0098] The first separation process is implemented within the ultrasonic cleaner 714, in which the cleaning solvent is agitated by a propeller or a fluid jet of the solvent to suspend the core sections. Additionally, an ultrasonic transducer is employed to deliver ultrasonic waves into the suspension to increase the efficiency of the chemical treatment. In some embodiments, the ultrasonic transducer can be positioned within the ultrasonic cleaner 714. In some embodiments, the ultrasonic transducer can be positioned adjacent to the wall of the ultrasonic cleaner 714.

[0099] As a result of agitation and ultrasonic action, the core section separates into components. Additionally, ultrasonic agitation with the cleaning solvent dissolves the anode and cathode binders and liberates the active material from the surface of the current collector. Further, the electrolyte solvent (e.g., DMC, PC, and EC) and the electrolyte salt (e.g., LiPF6) dissolve in the cleaning solvent. The suspension exiting the ultrasonic cleaner 714 contains (1) microscopic active material particles from both the anode and cathode, (2) larger separator fragments, and (3) chips of current collector material that can overflow from the cleaner. All of these components are suspended in a mixture of the cleaning solvent and the electrolyte salt.

[0100] A strainer 716 is employed within the system 700 and receives the suspension from the ultrasonic cleaner 714. The strainer 716 is configured to remove separator fragments and debris in the suspension as the suspension passes through the strainer 716. A pump 718 (diaphragm pump) is operably coupled to the strainer 716 and provides sufficient pressure to force the suspension through a filter - mixer - dryer (FMD) 720, and the microscopic active material is separated from the suspension. In some embodiments, the separation can be achieved by a centrifuge device instead of or in addition to the FMD 720. The centrifuge device can include, for example, a decanter, which can separate the materials in the mixture based on the different densities of the materials and discharge the materials with different densities out through different outlets. In some embodiments, the separation can be facilitated by mixing in a liquid. For example, the mixture can include two solid materials, each having a distinct density, and a heavy liquid having a density between the two densities of the two solid materials can be mixed into the mixture. Examples of heavy liquids can include, inter alia, bromoform, tetrabromoethane, methylene iodide, sodium polytungstate, sodium metatungstate, and lithium metatungstate.

[0101] The filtrate exiting the FMD720 returns to the washer 714 through nozzles located at the bottom of the washer 714. The nozzles can be configured to provide a fluid jet for agitation of the core section, or the agitation can be provided by a propeller. The agitation and ultra-sonic treatment processes within the washer 714 continue until (1) all of the core section is separated into individual components, (2) the cathode material is removed from the cathode current collector, and (3) the anode material is removed from the anode current collector.

[0102] The first separation process is carried out in a series of quasi-countercurrent washing stages (e.g., 3 stages are illustrated, but more or fewer stages can also be used). After a pre-specified length of time, the washer 714 is drained as the filtrate exiting the FMD720 is diverted to the first storage tank 730a (R1) for subsequent recycling. In the first washing stage, the FMD720 is refilled with filtrate stored from a subsequent washing stage (supplied from tank W2), which has a lower concentration of dissolved solids than the liquid from the ultrasonic washer 714. The material within the FMD720 is agitated in suspension and after a pre-specified length of time, the FMD720 is drained again as the filtrate exiting the FMD720 is diverted to the ultrasonic washer 714 for reuse. In the second washing stage, the FMD720 is refilled with filtrate stored from a subsequent washing stage (supplied from tank W1), which has a lower concentration of dissolved solids than the filtrate from washing stage 1. The material within the FMD720 is agitated in suspension and after a pre-specified length of time, the FMD720 is drained again as the filtrate exiting the FMD720 is diverted to the storage tank 730b (designated as W2 for the twice-used fluid) for subsequent reuse. In the third washing stage, the FMD720 is then refilled with distilled or fresh washing solvent, which has no dissolved solids. The washing process resumes until after a pre-specified length of time, the FMD720 is drained again and the filtrate exiting the FMD is diverted to the third storage tank 730c (designated as W1 for the once-used fluid) for subsequent reuse.

[0103] After final washing, the microscopic solids retained within the FMD720 are drained from the fluid by pressurizing the FMD720 with dry nitrogen. The solids are then heated and agitated under vacuum within the FMD720 to effect drying. In some embodiments, the wet solids can be removed from the suspension by other processes such as centrifugation for drying within a dedicated dryer (not shown in FIG. 7). The dried solids (i.e., the mixture of anode and cathode active materials) are discharged from the FMD720 or the dedicated dryer for subsequent processing such as re-lithiation.

[0104] After the first separation process, the cleaning facility 712 contains only the bare current collector part pieces. At this point, the cleaning facility 712 can be mechanically agitated to facilitate drainage of any remaining cleaning solvent. The cleaning facility 712 is then removed from the washer 714 and placed into the recirculating gas dryer 740. Heated gas (e.g., nitrogen) flows through the dryer 740 to agitate the current collector part pieces and evaporate the residual cleaning solvent. The gas from the dryer 740 is cooled to a low temperature to condense the solvent water vapor. The condensate is then transferred to a recycle tank (R1) 742 for subsequent purification and reuse. After the solvent water vapor has been condensed and removed, the gas is reheated and recirculated into the dryer 740 to evaporate additional solvent. After drying, the current collector part pieces are transferred from the cleaning facility 712 to a third separation process to separate the aluminum and copper flakes.

[0105] In the solvent recovery process, a solvent mixture (e.g., a cleaning solvent mixed with an electrolyte solvent and a salt) from the first recycle tank 730a (R1) is transferred to the distillation column 750. In the distillation column 750, the components of the effluent from the first recycle tank 730a are separated according to their individual boiling points. As the effluent progresses downward through the distillation column, the components are vaporized and subsequently condensed by one or more condensers and then stored in the container 752. The condenser and the associated container extract the electrolyte solvent (e.g., DMC), which is then transferred to a solvent recovery company outside the facility. At least one condenser, e.g., 774, operates at an appropriate temperature to condense the cleaning solvent (e.g., NMP) water vapor exiting the distillation column 750. The condensate from the condenser 774 is collected for reuse in the cleaning process. The liquid effluent from the bottom of the distillation column 750 is vaporized in the evaporator 760, and the resulting water vapor progresses upward through the distillation column 750, heating the distillation column 750 and providing the water vapor to the individual condensers. Solvents with high boiling points (e.g., EC and PC) are released from the evaporator, along with solids (e.g., LiPF6, PVDF, and CMC), into the waste stream.

[0106] A vacuum pump 772 is included within the system 700 and removes pure cleaning solvent water vapor from the FMD 720 during the drying operation. The vacuum pump 772 discharges the cleaning solvent water vapor to the condenser 774, where the water vapor is condensed from the distillation column 750 along with the cleaning solvent water vapor. The non-condensable gas (mainly nitrogen) exiting the condenser 774 passes through the adsorption layer 776 to remove the remaining organic water vapor and is then discharged to the atmosphere. In the third separation process, the anode current collector piece (e.g., copper with a density of 9.0 g / cm 3 is separated from the cathode current collector piece (e.g., aluminum with a density of 2.7 g / cm 3 using a vibration separation process.

[0107] The vacuum pump 772 is included within the system 700 and removes pure cleaning solvent water vapor from the solvent recovery still 760 and the FMD 720 during the drying operation. The vacuum pump 772 discharges the cleaning solvent water vapor under pressure to the condenser 774, where the cleaning solvent is condensed and collected for reuse. Non-condensable gases (mainly nitrogen) pass through the adsorption layer 776, removing the remaining organic water vapor and then being released to the atmosphere. In a third separation process, anode current collector pieces (e.g., copper with a density of 9.0 g / cm 3 are separated from the cathode current collector pieces (e.g., aluminum with a density of 2.7 g / cm 3 ) using a vibratory separation process.

[0108] Figures 8A - 8C illustrate a lithium equilibration process 800 during expandable direct recycling of a battery, according to some embodiments. In process 800, lithium-deficient cathode active materials 820a and 820b from the battery in different states of charge can reach lithium homogeneity by suspending the lithium-deficient cathode materials 820a and 820b in a mixture 810 that includes conductive carbon 814 in a lithium-containing salt solution 812.

[0109] As shown in Figure 8A, a cathode and anode active material mixture (e.g., produced during step 120 in method 100, step 230 in method 200, method 600, or method 700) is immersed in the lithium salt solution 812 to form a suspension. The solvent can be water or an organic solvent (e.g., NMP, DMC). The lithium salt can be, for example, LiPF6, LiOH, Li2SO4, LiCl, or LiNO3, and the concentration can be in the range of about 1M to about 5M, depending on the solubility of the salt. In some embodiments, the conductive carbon 814 can be contributed directly by the conductive component of the anode active material. In some embodiments, the conductive carbon 814 can be added into the mixture 810 from an external source.

[0110] Figure 8B shows the suspension progressing through a lithium equilibration process to achieve homogeneity in lithium content between lithium-deficient cathode materials 820a and 820b. After suspending lithium-deficient cathode materials 820a and 820b (Li x1 CoO2 and Li x2 CoO2 as shown (x1 > x2)) and conductive carbon 814 in a lithium salt solution 812, electrons and lithium ions begin to flow from Li x1 CoO2 820a to Li x2 CoO2 820b. Such transport produces a homogeneous composition Li x CoO2 for all the particles in the suspension, as illustrated in Figure 8C.

[0111] As described herein, the lithium equilibration process 800 occurs during chemical treatment (e.g., step 120 in method 100, step 230 in method 200, methods 600 and 700), thereby enabling simultaneous chemical separation and lithium equilibration. This is because the solvent NMP used in these treatment steps can dissolve electrode binders (e.g., PVDF, aqueous binder CMC, etc.) and is miscible with the battery electrolyte to form an ion-conductive lithium-containing solution.

[0112] In some embodiments, the lithium equilibration process can occur in sheet form before chemical treatment while the active electrode material is still attached to the current collector. When multiple sheets of current collectors coated with the cathode material are electrically connected, lithium ion and electron transfer can occur based on a similar mechanism illustrated in Figures 8A - 8C.

[0113] Figures 9A - 9C illustrate a lithium equilibration process 900 for an electrode in sheet form according to some embodiments. In process 900, two cathode sheets 920a and 920b are immersed in a lithium salt solution 915 contained within a container 910. The first cathode sheet 920a, as illustrated in Figure 9A, is Li x1The second cathode sheet 920b includes a first lithium-deficient material shown as CoO2 and Li x2 includes a second lithium-deficient material shown as CoO2.

[0114] FIG. 9B shows that two cathode sheets 920a and 920b are electrically coupled to each other, thereby enabling the transport of electrons and lithium ions between the two cathode sheets 920a and 920b. More specifically, as illustrated in FIG. 9C, lithium ions exit from the first cathode sheet 920a and enter the second cathode sheet 920b, thereby producing two cathode sheets 930a and 930b having the same cathode material Li x CoO2.

[0115] In some embodiments, after equilibration, the cathode active material is separated from the current collector in a washing process similar to that described above with respect to the core section, resulting in a cathode active material that is uniform but has a non-stoichiometric amount of lithium.

[0116] A lithium-deficient cathode material having a homogeneous lithium distribution can then be assayed to determine the lithium stoichiometry. Lithium salts (e.g., LiOH, Li2CO3, etc.) can be added to address the lithium deficiency using a dry powder or wet slurry mixing device (e.g., a rotary mixer, blender, etc.), i.e., re-lithiation. The resulting mixture is heat-treated to restore the lithium stoichiometry into the active material and can address damage to the active material structure.

[0117] The re-lithiation of a lithium-deficient cathode material can be achieved via at least two approaches. In the first approach, a lithium-containing material is employed. The lithium-containing material has a particle size similar to that of the lithium-deficient cathode material particles to be re-lithiated. Examples of such lithium-containing materials include, among others, LiOH·H2O powder, Li2CO3, and LiCH3COO. The description herein uses LiOH·H2O for illustrative purposes only. In some embodiments, any other lithium-containing material described herein can also be used.

[0118] In this first approach, a lithium-deficient cathode material (e.g., Li x CoO2 (x < 1)) is homogeneously mixed with the lithium-containing material to form a mixture. In some embodiments, the mixture is in a stoichiometric ratio of 1 mole of Li x CoO2 to (1 - x) moles of LiOH·H2O. Typically, Li x CoO2 from a cathode that has completed its full cycle (i.e., end of service life) has an x value of about 0.5. In this case, the mass ratio of 1Li x CoO2 to (1 - x) LiOH·H2O is about 298.6 milligrams (mg) to 177.46 mg.

[0119] In some embodiments, the x value can deviate from 0.5 (e.g., the battery has not completed its full cycle). In these cases, the x value can be determined by elemental analysis techniques such as inductively coupled plasma atomic emission spectroscopy (ICP-AES). The molar amount of (1 - x) moles of LiOH·H2O can then be adjusted as appropriate.

[0120] In some embodiments, an excess amount of LiOH·H2O can be added to the mixture to compensate for lithium loss during high-temperature heating. In some embodiments, the excess amount of LiOH·H2O can be from about 3% to about 8% of the original amount (e.g., about 3%, about 3.5%, about 4%, about 4.5%, about 5%, about 6%, about 7%, or about 8%, including any value and sub-range therebetween).

[0121] The resulting homogeneous mixture can be pressed into a cylindrical pellet form or any other suitable compacted form. The pellet form can facilitate uniform processing during relithiation. The cylindrical pellets are then heated at a high temperature in air. The high temperature of the heating can be any value from 100°C to about 1000°C (e.g., about 100°C, about 200°C, about 300°C, about 400°C, about 500°C, about 600°C, about 700°C, about 800°C, about 900°C, or about 1000°C, including any value and sub-range therebetween). The duration of the heating can be from about 1 hour to about 24 hours (e.g., about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 10 hours, about 12 hours, or about 24 hours, including any value and sub-range therebetween). In some embodiments, the resulting homogeneous mixture can be sintered without directly forming a compacted form. For example, a rotary kiln can be used to directly sinter the homogeneous mixture in powder form.

[0122] In some embodiments, the high temperature used in the heating can be substantially equal to or below 500°C, which is below the sintering temperature of the cathode material. Heating within this temperature range can save energy and reduce the decomposition of residual organics in the material and carbon deposits. The decomposition can be harmful because it can form gases that prevent cracks in the LiCoO2 crystal from healing during heating. Improper crack healing can allow the particles to break, which can then reduce the size of the LiCoO2 particles. As a result, the particle morphology of the LiCoO2 particles can be different from that used to form a new battery.

[0123] The heating step can drive the reaction and cause the recrystallization of LiCoO2 according to the following equation (1). 4Li x CoO2 + 4(1 - x)LiOH·H2O → 4LiCoO2 + 6(1 - x)H2O + (1 - x)O2 (1) The resulting relithiated cathode material from equation (1) can then be removed from the oven and is ready to be reused as a raw material for cathode manufacturing, i.e., a battery-grade cathode material.

[0124] Figures 10A and 10B illustrate a method 1000 of relithiation according to a second approach, according to some embodiments. The description of method 1000 herein uses LiCoO2 as the cathode material for illustrative purposes only. In practice, any other cathode material described herein can also be relithiated via method 1000.

[0125] Method 1000 starts with a lithium-deficient cathode material 1011 (e.g., produced from step 120 in method 100, step 230 in method 200, method 600, or method 700). At 1010, the lithium-deficient cathode material (e.g., powdered Li x CoO2) is placed into a cathode suspension 1012 that contains at least one lithium salt. Examples of lithium salts that can be used here include, but are not limited to, lithium sulfate, lithium nitrate, and lithium chloride suspended in an aqueous suspension. Alternatively, an organic solvent can also be used, and examples of such organic solvents can include dimethyl carbonate (DMC) and ethylene carbonate (EC).

[0126] In some embodiments, the concentration of the cathode suspension 1012 ranges from about 100 micrograms (μg) / liter (L) to about 1 mol / L of the artificial or "pure" solution of seawater lithium concentration, which may mean that only lithium-based salts are in the solution. In some embodiments, the method 1000 can utilize any lithium-ion containing solution. The lithium-deficient cathode material can be combined with a lithium salt suspension in a 1:1 volume ratio.

[0127] In 1020 of method 1000, Li x CoO2 / Li in the lithium salt suspension 1012 x CoO2 is re-lithiated within the re-lithiation electrochemical flow system 1015, which is illustrated in Figure 10B. The system 1015 includes a galvanic cell, which includes a cathode chamber 1022, an anode chamber 1040, and a galvanic separator 1030. The cathode chamber 1022 and the anode chamber 1040 can be made of any non-reactive material such as, among others, stainless steel, glass, or polymer. The cathode chamber 1022 and the anode chamber 1040 each have an opening that interfaces with the galvanic separator 1030. In some embodiments, a first seal (e.g., made of rubber, silicone, or other elastic material) is disposed between the cathode chamber 1022 and the galvanic separator 1030 to prevent leakage. In some embodiments, a second seal is disposed between the anode chamber 1040 and the galvanic separator 1030 to prevent leakage.

[0128] The working electrode 1072 is inserted into the cathode chamber 1022. In some embodiments, the working electrode 1072 can be made from a nickel mesh. In some embodiments, the working electrode 1072 can be made from a carbon plate. The counter electrode 1073 is inserted into the anode chamber 1040. In some embodiments, the counter electrode 1073 can include a platinum (Pt) mesh. An additional reference electrode (not shown in FIGS. 10A - 10B) can also be inserted into either the cathode chamber 1022 or the anode chamber 1040. In some embodiments, the reference electrode can be made from Ag / AgCl.

[0129] A constant - current power supply 1070 is electrically connected to each of the working electrode 1072 and the counter electrode 1073 through a conductor. In some embodiments, the working electrode 1072 functions as a current collector while the lithium - deficient cathode material functions as a reactant.

[0130] The anode chamber 1040 is supplied from a lithium reservoir 1060 through a pressure source 1062 and a feed pipe 1064 and is hydraulically connected thereto. In some embodiments, the lithium reservoir 1060 has a first volume that exceeds a second volume of the anode chamber 1040. In some embodiments, the total charge - storage capacity of the lithium reservoir 1060 exceeds the charge - storage capacity of the anode chamber 1040 by at least five times. The liquid is returned to the lithium reservoir 1060 through a return pipe 1066.

[0131] In some embodiments, the pressure source 1062 includes a pump such as a centrifugal pump. In some embodiments, any other suitable technique can be used. For example, the lithium reservoir 1060 can feed the anode chamber 1040 via gravity and the pressure source 1062 can be disposed within the return pipe 1066.

[0132] In some embodiments, the lithium salt-containing solution in the anode chamber 1040 can be the same as the lithium salt-containing solution used to create the suspension 1012. This provides the ability to omit the lithium replenishment process and reduce the cost of restoring / supplementing depleted lithium. For example, the lithium salt-containing solution in the anode chamber 1040 can be a "pure" solution, meaning that only lithium-based salts are present in the solution. In another example, the reservoir 1060 can be a "non-pure" brine pool containing non-lithium-based salts, and the lithium salt-containing solution in the anode chamber 1040 can be brine in the brine pool containing, for example, 1 to 2 weight percent lithium and any number of other component elements.

[0133] In some embodiments, the reservoir 1060 can contain seawater, and the lithium salt-containing solution in the anode chamber 1040 can also be seawater containing about 183 micrograms (μg) / liter (L). In yet another alternative, the reservoir 1060 can contain lithium-containing waste water. Also, in yet another example, the reservoir 1060 can contain any number of lithium-containing ores, such as spodumene, amblygonite, lepidolite, or eucryptite, and an alkali-metal hydroxide (e.g., KOH) solution can flow over or through the ore to result in a lithium-ion-containing solution due to the hydroxide solution leaching effect.

[0134] In yet another example, the lithium reservoir 1060 can be a source of naturally occurring water that flows to resupply depleted lithium during operation of the re-lithiation electrochemical flow system 1015. For example, the flow can be caused by pumping naturally occurring water during operation of the re-lithiation electrochemical flow system. In another example, the flow results from natural events that can include, but are not limited to, rainfall, stream or river flow, hot springs in the ocean, tidal currents, or wave action. Also, in yet another example, tidal currents or wave action can be used to fill the lithium reservoir 1060, which then, under gravity, causes a lithium salt-containing solution to flow into the anode chamber 1040. Regardless of the lithium source, the flow of lithium from the reservoir 1060 can replenish the lithium in the lithium salt-containing solution, the anode (positive) electrode, and ultimately, the re-lithiation reaction during operation, whether the lithium is from a stream, seawater, lithium ore, or pure lithium salts.

[0135] The galvanic separator 1030 can include any type of galvanic separator that allows lithium ions to pass through effectively. In some embodiments, the galvanic separator 1030 includes a ceramic separator. In some embodiments, the galvanic separator 1030 includes a porous polymer separator. In some embodiments, the porous polymer separator can be used when the lithium salt-containing solution is a pure lithium-based salt solution because the pure solution usually does not contain non-lithium ions that can pierce the porous polymer separator. In some embodiments, an ion-selective polymer that is permeable only to lithium ions can be used for pure lithium salt-based solutions and non-pure solutions (e.g., seawater, seawater brine, and / or lithium ore-based solutions). In some embodiments, the ceramic separator can be used for pure lithium salt-based solutions and non-pure solutions (e.g., seawater, seawater brine, and / or lithium ore-based solutions). Examples of suitable polymer separators include, but are not limited to, fibrous paper (e.g., cellulose-based), or a three-layer polypropylene-polyethylene-polypropylene membrane having a pore size of about 0.21 × 0.05 μm and a porosity of about 39%. Examples of suitable ceramic separators include, but are not limited to, Li 1+x+y Al x (Ti, Ge) 2-x Si y P 3-y O, (Li x , La y )TiO z , and (Li x , La y )ZrO z including.

[0136] During operation, the cathode chamber 1022 is installed in the aqueous suspension 1012 with Li xThe CoO₂-containing solution is filled. The anode chamber 1040 is filled with a lithium salt-containing solution that can be under static or flowing conditions. In some embodiments, the lithium salt-containing solution is under static conditions, thereby enabling the operation of the system 1015 without the reservoir 1060, the pressure source 1062, and the flow and return pipes 1064 and 1066. The anode chamber lithium salt-containing solution can be the same or different from the lithium salt-containing solution used to make the suspension 1012.

[0137] An anode current is applied to the anode chamber 1040, that is, it is a constant current power supply source potential such that electrons flow in the direction of arrow 1076. As the electrolyte (lithium salt-containing solution) in the anode chamber 1040 undergoes an oxygen evolution reaction (OER) 1078, Li in the cathode chamber 1022 x CoO₂ is reduced, and lithium ions 1074 are x intercalated into LiCoO₂ to form LiCoO₂.

[0138] The theoretical mechanism of the reaction is shown in Equation 2-3 below. Li x CoO₂+(1-x)Li + +(1-x)e - →LiCoO₂(2) 2H₂O→O₂+4H + +4e - (3)

[0139] The potential of each of the working electrode 1072 and the counter electrode 1073 is measured with respect to the reference electrode until the potential of the working electrode 1072 with respect to the reference electrode reaches about -0.8V to about -1.0V with respect to Ag / AgCl. For most lithium ion battery cathode materials, discharging to -0.8V to -1V with respect to Ag / AgCl can fully restore the lithium content.

[0140] One advantage of the recharge lithiation electrochemical flow system 1015 is that the amount of lithium ion intercalation can be precisely controlled by the cut-off potential. Other recharge lithiation approaches typically require quantification of the amount of lithium depletion (i.e., the x value in LixCoO2) before determining the optimal amount of lithium-containing material to add. In contrast, the recharge lithiation electrochemical flow system 1015 can completely convert x to 1 by controlling the cut-off voltage of the electrochemical recharge lithiation process without quantifying x, since the specific lithium content x in the battery cathode material (e.g., LixCO2, LixFePO4) corresponds to unique electrode material properties (e.g., open circuit voltage, conductivity, lithium transport properties, etc.).

[0141] After reactions (2)-(3), LixCoO2 is re-lithiated to LiCoO2. The re-lithiated LiCoO2 can be removed from the cathode chamber 1022 for reuse (e.g., to fabricate a new battery). In some embodiments, LiCoO2 can be further washed with water and dried before reuse. In some embodiments, the morphology of the re-lithiated LiCoO2 can be improved via a heating process, and thereafter, the re-lithiated LiCoO2 can have the same crystal structure as commercially available LiCoO2.

[0142] FIG. 11 is a flowchart illustrating a method 1100 of chemical treatment and separation in the direct recycling of batteries, according to some embodiments. Method 1100 includes, at 1110, a primary cleaning process within a mixing device (e.g., an FMD and / or a centrifuge type device such as a batch centrifuge or a continuously operating decanter) to clean the core segments produced from the batteries. Each core segment can be substantially similar to the core segments in method 100 described with reference to FIG. 1. For example, each core segment can include at least one anode / cathode / separator assembly. In this step, some or all of the organic components such as electrolytes (e.g., EC, DMC, and PC) and binders (e.g., PVDF and CMC) and salts (e.g., LiPF6) are dissolved in a cleaning solvent (e.g., NMP, DMF, DMSO, or DMAc). The dissolved components (e.g., solvent, electrolyte, salt, and binder) are separated from the solid components (e.g., anode and cathode materials, separator, current collector, and battery case) via separation methods such as decantation, filtration, centrifugation, decanting, solvent washing, heating, air drying, vacuum drying, or any combination thereof. In some embodiments, some of the organic components such as electrolytes or binders can remain mixed with the solid components.

[0143] In some embodiments, method 1100 also includes, at 1120, a heat treatment process that exits the cleaning process at 1110 and removes or decomposes some or all of the organic components remaining in the solid component. In some embodiments, the heat treatment process also removes or decomposes pieces of the separator and / or pieces of the battery packaging. In some embodiments, the solid component is heated to at least 100 degrees Celsius. In some embodiments, the solid component is heated to 200, 300, 400, 500, 600, 700, or 800 degrees Celsius. In other embodiments, the solid component is heated to above 800 degrees Celsius. In some embodiments, the solid component is heated in an oxidizing atmosphere such as air, oxygen gas, oxygen gas mixed with nitrogen gas, or other combinations. In other embodiments, the solid component is heated in a reducing atmosphere such as hydrogen gas, hydrogen gas mixed with steam, hydrogen gas mixed with nitrogen gas, carbon monoxide gas, carbon monoxide gas mixed with carbon dioxide, or other combinations. In yet other embodiments, the solid component is heated in an inert atmosphere such as nitrogen gas, argon gas, or other combinations.

[0144] Method 1100 also includes, at 1130, a separation process configured to extract a mixture of anode and cathode materials from the rest of the solid components. The separation can be carried out, for example, via ultrasonic cleaning in an ultrasonic cleaning solvent (e.g., NMP, DMF, DMSO, DMAc, ethanol, propanol or water, or acidic water, or alkaline water). In this step, the solid components are separated into individual components including the cathode / anode materials (usually in particulate form), separator pieces, current collector pieces, and / or battery packaging pieces. In some embodiments, at least one filtration system is employed to separate larger separator pieces, current collector pieces, and / or battery packaging pieces from the mixture of anode and cathode materials. In some embodiments, at least one filtration system includes a separate ultrasonic transducer and breaks up the agglomeration of the particles. The mixture of anode and cathode materials is then taken out for further separation and / or re-lithiation, while the rest of the components can be discarded or undergo further separation.

[0145] In 1140, the components in the effluent from the primary wash 1110 are separated according to their individual boiling points (e.g., using a distillation column). As the effluent progresses downward through the distillation column, the components are vaporized and then condensed (at 1150) by one or more condensers operating at an appropriate condensation temperature. The condenser is configured to extract an electrolyte solvent (e.g., DMC), which is then collected for transfer to a solvent recovery company outside the facility. At least one condenser is incorporated within the solvent recovery system and operates at an appropriate temperature to achieve solvent recovery at 1170, condensing the wash solvent vapor exiting the distillation column. The wash solvent condensed from this condenser is combined with the solvent recovered from other operations (e.g., drying) and returned to the primary wash process 1110. The liquid effluent from the bottom of the distillation column (e.g., after 1140) is vaporized in an evaporator (at 1160), and the resulting water vapor progresses upward through the distillation column, heating the column and providing the water vapor to the individual condensers. Solvents with high boiling points (e.g., EC and PC) are released from the evaporator, along with solids (e.g., LiPF6, PVDF, and CMC), into the waste stream. (Conclusion)

[0146] Although various embodiments of the present invention have been described and illustrated herein, those skilled in the art will readily conceive of various other means and / or structures for performing the functions and / or achieving one or more of the results and / or advantages described herein, and such variations and / or modifications are each to be regarded as within the scope of the embodiments of the invention described herein. More generally, those skilled in the art will readily understand that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary, and that the actual parameters, dimensions, materials, and / or configurations will depend upon the particular application or applications for which the teachings of the invention are used. Those skilled in the art will be able to recognize, or confirm using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Accordingly, the foregoing embodiments are presented by way of example only, and it is to be understood that the embodiments of the invention may be practiced otherwise than as specifically described and claimed within the scope of the appended claims and their equivalents. Embodiments of the invention of the present disclosure are directed to each and every individual feature, system, article, material, kit, and / or method described herein. Additionally, any combination of two or more such features, systems, articles, materials, kits, and / or methods, provided such features, systems, articles, materials, kits, and / or methods are not mutually inconsistent, is included within the scope of the invention of the present disclosure.

[0147] Embodiments can be implemented using hardware, software, or a combination thereof. When implemented in software, the software code can be executed on any suitable processor or set of processors, whether provided in a single computer or distributed among multiple computers. Further, it should be understood that the computer can be embodied in any of several forms, such as a rack-mounted computer, a desktop computer, a laptop computer, or a tablet computer. Additionally, the computer can be embodied in a device that is not generally considered a computer but has suitable processing capabilities, including a personal digital assistant (PDA), a smartphone, or any suitable portable or facility electronic device.

[0148] Also, the computer can have one or more input and output devices. These devices can be used, among other things, to present a user interface. Examples of output devices that can be used to provide a user interface include a printer or display screen for visual presentation of output and a speaker or other sound-generating device for audible presentation of output. Examples of input devices that can be used for a user interface include a keyboard and pointing devices such as a mouse, touchpad, and digitizing tablet. As another example, the computer can receive input information through speech recognition or in other audible formats.

[0149] Such a computer can be interconnected by one or more networks in any suitable form, including forms such as a local area network or a wide area network, such as a corporate network, an intelligent network (IN), or the Internet. Such networks can be based on any suitable technology, can operate according to any suitable protocol, and can include wireless networks, wired networks, or fiber optic networks.

[0150] (For example, designing and fabricating the reservation / delivery structure disclosed above) The various methods and processes outlined herein can be coded as software executable on one or more processors employing any one of a variety of operating systems or platforms. Additionally, such software can be written using any of several suitable programming languages and / or programming or scripting tools and can be compiled as executable machine language code or intermediate code to be executed on a framework or virtual machine.

[0151] Also, various concepts of the present invention can be embodied as one or more methods, examples of which are provided. The acts performed as part of a method can be ordered in any suitable manner. Thus, in an illustrative embodiment, although shown as sequential acts, embodiments can also be constructed in which the acts are performed in a different order than illustrated, which can include performing some acts simultaneously.

[0152] All publications, patent applications, patents, articles, and other references mentioned herein are hereby incorporated by reference in their entirety.

[0153] All definitions as defined and used herein are to be understood as overriding dictionary definitions, definitions in incorporated by reference documents, and / or ordinary meanings of defined terms.

[0154] The indefinite articles "a" and "an" as used in the specification and claims are to be understood to mean "at least one" unless clearly indicated otherwise.

[0155] As used in the specification and claims, the phrase "and / or" should be understood to mean "either or both" of the elements so joined, i.e., elements that in some cases coexist conjunctively and in other cases disjunctively. Multiple elements recited in "and / or" clauses are to be construed in the same fashion, i.e., as "one or more" of the elements so joined. Other elements may optionally be present whether related or unrelated to the elements specifically identified by the "and / or" clause. Thus, by way of non-limiting example, a reference to "A and / or B" when used in conjunction with open-ended terms such as "comprising" can refer, in one embodiment, to only A (optionally including elements other than B), in another embodiment, to only B (optionally including elements other than A), and in yet another embodiment, to both A and B (optionally including other elements).

[0156] As used in the specification and claims, "or" is to be understood to have the same meaning as "and / or" as defined above. For example, when separating items in a list, "or" or "and / or" is inclusive, i.e., at least one of the inclusion, but also more than one of some elements or list of elements, optionally including additional unrecited items. In contrast, terms such as "only one of" or "exactly one of" clearly indicate, or when used in claims, "consisting of" will refer to the inclusion of exactly one element of some elements or list of elements. Generally, the term "or" as used herein is to be construed to indicate exclusive alternatives (i.e., "one or the other but not both") only when preceded by terms such as "either," "one of," "only one of," or "exactly one of." "Consisting essentially of" when used in a claim shall have its ordinary meaning as used in the field of patent law.

[0157] As used in the specification and claims, the phrase "at least one" refers to at least one element selected from any one or more of the elements in a list of one or more elements, but does not necessarily include at least one of every element specifically recited in the list of elements, and is to be understood as not excluding any combination of elements in the list of elements. This definition also allows for the optional presence of elements other than those specifically identified in the list of elements to which the phrase "at least one" refers, whether related or unrelated to the specifically identified elements. Thus, by way of non-limiting example, "at least one of A and B" (or equivalently "at least one of A or B", or equivalently "at least one of A and / or B") can, in one embodiment, refer to at least one A (optionally including elements other than B) that optionally includes more than one and in which no Bs are present; in another embodiment, to at least one B (optionally including elements other than A) that optionally includes more than one and in which no As are present; in yet another embodiment, to at least one A that optionally includes more than one and to at least one B that optionally includes more than one (optionally including other elements), and the like.

[0158] In the claims and the foregoing specification, all transitional phrases such as "comprising", "including", "carrying", "having", "containing", "involving", "holding", "composed of", and equivalents thereof are to be understood to be open-ended, i.e., to mean including but not limited to. As set forth in Section 2111.03 of the United States Patent and Trademark Office's Manual of Patent Examining Procedure, only the transitional phrases "consisting of" and "consisting essentially of" are to be regarded as limiting or semi-limiting transitional phrases, respectively.

Claims

1. A method, the method comprising: placing a quantity of battery waste in a solvent, the quantity of battery waste including a cathode active material, and the solvent being free of electrolyte salts; and placing a lithium source in the solvent; and mixing the cathode active material and the lithium source in the solvent to create an ionic network A method as described above.

2. The method of claim 1, wherein the solvent includes at least one of dimethylformamide (DMF), n-methylpyrrolidone (NMP), ethanol, methanol, isopropanol, acetone, ethylene carbonate (EC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), propylene carbonate (PC), or water.

3. The method of claim 1, wherein the battery waste further includes at least one of an anode active material or a separator material.

4. The battery waste includes at least one of an anode current collector or a cathode current collector, and the method further includes exposing the battery waste to a dissolving solvent configured to dissolve at least one of the anode current collector or the cathode current collector and / or separate from other components of the battery waste.

5. The method of claim 4, wherein the dissolving solvent includes ammonia.

6. The method of claim 1, further comprising re-lithiating the cathode active material.

7. The method of claim 6, wherein the re-lithiation is via at least one of adding a lithium-containing material to the cathode active material.

8. The cathode active material is LiCoO ２ , LiMn ２ O ４ , LiFe ｔ M １－ｔ PO ４ (LFMP), or LiNi ａ Mn ｂ Co ｃ A ｄ O ２ The method according to claim 1, comprising at least one of them, where a + b + c + d = 1 and A = Al, Zr, or Mg.

9. A method, the method comprising: combining battery waste including at least a cathode material and a lithium source in a solvent, the solvent being free of electrolyte salts, and the cathode material including a cathode current collector; and mixing the cathode material and the lithium source in the solvent to create an ionic network; and exposing the battery waste to a dissolving solvent A method as described above. The method wherein the dissolving solvent is configured to dissolve at least one of the anode current collector and the cathode current collector contained in the battery waste and / or separate it from other components of the battery waste.

10. The method according to claim 9, wherein the solvent contains at least one of dimethylformamide (DMF), n-methylpyrrolidone (NMP), ethanol, methanol, isopropanol, acetone, ethylene carbonate (EC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), propylene carbonate (PC), or water.

11. The method according to claim 9, wherein the dissolving solvent contains ammonia.

12. The method according to claim 9, wherein the battery waste further contains at least one of an anode material or a separator material.

13. The method according to claim 12, further comprising treating the battery waste into a plurality of core sections, each core section of the plurality of core sections containing the anode material, the cathode material, and the separator material.

14. The method according to claim 9, further comprising re-lithiating the cathode material.

15. The method according to claim 14, wherein the re-lithiation is through at least one of addition of a lithium-containing material to a cathode active material.

16. A method, the method comprising: mixing battery waste containing at least a cathode material and a lithium source in a solvent to create an ionic network, wherein no electrolyte salt is present in the solvent, and the solvent contains at least one of dimethylformamide (DMF), n-methylpyrrolidone (NMP), ethanol, methanol, isopropanol, acetone, ethylene carbonate (EC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), propylene carbonate (PC), or water; and exposing the battery waste to a dissolving solvent. comprising The method wherein the dissolving solvent is configured to dissolve at least one of the anode current collector and the cathode current collector contained in the battery waste and / or separate it from other components of the battery waste.

17. The method according to claim 16, wherein the dissolving solvent contains ammonia.

18. The method according to claim 16, wherein the battery waste further comprises at least one of an anode material or a separator material.

19. The method according to claim 16, further comprising re-lithiating the cathode material.

20. The method according to claim 19, wherein the re-lithiation is via at least one of addition of a lithium-containing material to the cathode active material.

21. The cathode material is LiCoO ２ , LiMn ２ O ４ , LiFe ｔ M １－ｔ PO ４ (LFMP), or LiNi ａ Mn ｂ Co ｃ A ｄ O ２ The method according to claim 16, comprising at least one of the following, where a + b + c + d = 1 and A = Al, Zr, or Mg.

22. A method, wherein the method comprises: processing at least one battery into a plurality of core sections, each core section in the plurality of core sections comprising an anode section, a cathode section comprising a cathode material, a separator section disposed between the anode section and the cathode section, and an electrolyte; disposing the plurality of core sections in a solvent to produce a mixture of cathode materials from the plurality of core sections; and wherein no electrolyte salt is present in the solvent, the solvent and the electrolyte form an ion-conductive medium, and the mixture of the cathode materials is characterized by a substantially homogeneous distribution of active elements in the cathode material.

23. The at least one battery includes a lithium ion battery, and the cathode material is LiCoO ２ , LiMn ２ O ４ , LiFe ｔ M １－ｔ PO ４ (LFMP), or LiNi ａ Mn ｂ Co ｃ A ｄ O ２ The method according to claim 22, comprising at least one of, where a + b + c + d = 1 and A = Al, Zr, or Mg.

24. The method according to claim 23, wherein disposing the plurality of core sections in the solvent comprises disposing the plurality of core sections in at least one of dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), or dimethylacetamide (DMAc).

25. The method according to claim 22, wherein the at least one battery comprises a first battery in a first state of charge and a second battery in a second state of charge different from the first state of charge.

26. The method according to claim 22, wherein the ion-conductive medium further comprises conductive carbon from at least one anode section in the plurality of core sections.

27. The method according to claim 22, wherein the mixture of the cathode materials is produced without an electrochemical process.

28. The method according to claim 22, wherein the mixture of the cathode materials comprises a lithium-deficient compound of the active element in the cathode material.

29. The anode section in each core section contains an anode material, the mixture of the cathode materials further contains the anode material from the plurality of core sections, and the method further includes extracting the cathode material from the mixture of the cathode material and the anode material. The method according to claim 22.

30. The method according to claim 29, further comprising re-lithiating the cathode material extracted from the mixture of the cathode material and the anode material to produce a battery-grade cathode material.

31. The method according to claim 22, further comprising deactivating the at least one battery before treating the at least one battery with the plurality of core sections.

32. The method according to claim 22, further comprising, after deactivating the at least one battery, using a conductive needle to pierce the at least one battery to estimate the discharge state of the at least one battery.

33. The at least one battery includes a plurality of batteries, and the method according to claim 22, further comprising sorting the plurality of batteries into a first group of batteries having a first cathode material and a second group of batteries having a second cathode material.

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