Battery inactivation

Abstract

Examples of methods for passivating lithium-containing batteries are disclosed. One example provides a method for discharging a lithium-containing battery, the method including the steps of adding the lithium-containing battery to a bath, adding an oxidizing fluid to the bath, adding carbon dioxide to the bath, pressurizing the bath, heating the bath to form lithium carbonate in the lithium-containing battery, reducing the heat and pressure in the bath, and removing the battery from the bath.

Description

[Technical Field]

[0001] This application relates to the field of lithium ion batteries, and more particularly to passivating lithium ion batteries. [Background technology]

[0002] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims priority to U.S. Provisional Application No. 62 / 934,446, entitled "Battery Passivation," filed November 12, 2019, the entire contents of which are incorporated herein by reference in their entirety for all purposes.

[0003] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT This invention was made with government support under Contract No. EE0008475 awarded by the U.S. Department of Energy. The government has certain rights in this invention.

[0004] Lithium-ion batteries power products ranging from automobiles to smartphones. These batteries are rechargeable for many cycles, resistant to various environmental factors, and have a relatively long useful life. Nevertheless, they eventually fail or are discarded before failure, thus contributing to a significant increase in the waste stream. This situation has led to environmental regulations, industry standards, and collection services to promote the recycling of lithium-ion batteries. Summary of the Invention

[0005] Examples related to passivating lithium-containing batteries are disclosed. One example is a method for passivating a lithium-containing battery, comprising: adding lithium-containing batteries to the bath; adding an oxidizing fluid to the vessel; adding carbon dioxide to the tank; pressurizing the vessel; heating the bath to form lithium carbonate within the lithium-containing battery; reducing the heat and pressure in the vessel; removing the battery from the tank; The present invention provides a method comprising: [Brief explanation of the drawings]

[0006] [Figure 1A] FIG. 1 illustrates an exemplary method for passivating a lithium-containing battery according to one embodiment of the present disclosure. [Figure 1B] FIG. 1 illustrates an exemplary method for passivating a lithium-containing battery according to one embodiment of the present disclosure. [Figure 2] FIG. 1 illustrates another exemplary method for passivating a lithium-containing battery according to an embodiment of the present disclosure. [Figure 3] FIG. 1 illustrates an example of a titration relationship between the amount of LiOH and the amount of H2SO4, according to an embodiment of the present disclosure. [Figure 4] FIG. 1 shows a plot of the concentration of active lithium in an untreated lithium-containing battery and in batteries that have undergone one, two, and three CO2 deactivations, according to one embodiment of the present disclosure. [Figure 5] FIG. 1 shows a plot of the temperature profile of a lithium-containing battery during a nail penetration test, according to one embodiment of the present disclosure. [Figure 6] FIG. 1 shows plots of discharge curves for a charged untreated lithium-containing battery and a battery that has been subjected to one, two, and three CO2 passivations, according to one embodiment of the present disclosure. [Figure 7] FIG. 1 shows an example chromatogram of electrolyte material removed from a lithium-containing battery according to an embodiment of the present disclosure. [Figure 8] FIG. 1 illustrates an example of a system for extracting electrolyte from a battery according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0007] Recycling lithium-ion batteries is challenging and can pose various hazards. One such hazard is thermal runaway, characterized by rapid, uncontrolled heating of the battery due to a positive feedback loop between the battery cell temperature and the conductivity of the electrolyte within the battery. Overheating due to thermal runaway can cause the melting of lithium chains within the battery, resulting in or accelerating a violent chemical reaction and the potential for fire. Even used lithium-ion batteries may be affected by thermal runaway, leaving some amount of lithium chains remaining. Furthermore, treatment processes such as using saltwater to discharge batteries or using only supercritical carbon dioxide to extract the electrolyte from the battery may not be able to sufficiently discharge or passivate all of the lithium remaining in the battery. Because batteries in recycling facilities or during transportation may be exposed to high temperatures (e.g., from the environment or the recycling process), such conditions can trigger thermal runaway in waste-stream lithium-ion batteries if a threshold temperature is reached. Therefore, there is a need to prevent thermal runaway in used lithium ion batteries to ensure safe recycling and / or disposal of used lithium ion batteries and to help reduce costs associated with transporting and recycling used lithium ion batteries.

[0008] Furthermore, discharging does not address other risks associated with the health of waste stream lithium-ion batteries, such as electrolyte material, gas content, electrolyte aging, lithium dendrites, delaminated lithium carbon, container corrosion, and blown fuses, which can be exacerbated when handling large numbers of battery cells.

[0009] Thus, examples are disclosed that relate to passivating lithium chains in waste-stream lithium-ion batteries, thereby inactivating the battery and helping to prevent thermal runaway. In this specification, passivation is used to mean the removal of stored energy, as opposed to discharging the battery, which involves oxidation at the anode and reduction at the cathode. Briefly, the disclosed method includes the steps of: inactivating the battery by adding an oxidizing agent (e.g., an oxidizing fluid) and carbon dioxide to a vessel containing the lithium-containing battery; and pressurizing and heating the vessel to form lithium carbonate within the lithium-containing battery. In some examples, pressurizing the vessel includes forming a condensed carbon dioxide phase. The condensed carbon dioxide can help passivate remaining lithium ions, lithium metal, and lithium alloys within the battery, while the oxidizing fluid can help the condensed carbon dioxide reach the lithium through the solid electrolyte interface (SEI) and / or the lithium carbonate passivation layer surrounding the active lithium chains within the battery. During battery operation, the SEI allows Li transport while blocking electrons to prevent electrolyte decomposition. Without wishing to be bound by theory, in the disclosed passivation process, the oxidizing fluid may react with lithium to form lithium hydroxide. For example, when water is used as the oxidizing fluid, 2Li(s) + 2H2O → 2LiOH(aq) + H2(g) holds. This is a violently exothermic reaction that produces flammable hydrogen gas; however, carbon dioxide may help mitigate the potentially violent nature of the reaction between water and lithium. Furthermore, the evolution of hydrogen gas may contribute to disrupting the passivating properties of the SEI, allowing carbon dioxide to reach any remaining lithium in the battery and form lithium carbonate. The disclosed examples can be used with any suitable type of lithium-ion battery, including batteries with liquid electrolytes, solid electrolytes (e.g., polymer electrolytes), composite electrolytes, and batteries using metallic lithium or lithium alloy electrodes. Some examples of batteries that have been successfully passivated include those with initial measurements between 0 and 3.2 V (for lithium iron phosphate systems) and 0 to 30 μmol / cm in the anode. 2and initial measurements of 0-4.2V (for NMC systems) and 0-5.3μmol / cm in the anode. 2 Examples of batteries with residual lithium include batteries with a low residual lithium content of 0.01%. An example of a process that results in a relatively low residual lithium is as follows: Place the battery in a 4 L autoclave containing 400 mL of 3% hydrogen peroxide (the battery is positioned above the fluid), seal the vessel, introduce CO2 at room temperature to 900°C, and hold the system for 30 minutes. Heat the vessel to 120°C while maintaining a pressure below 900 psi (e.g., between 500 and 900 psi), and hold the system at that temperature for 30 minutes. Next, cool to 40°C in approximately 30 minutes (e.g., using a cooling coil), depressurize the vessel, open the vessel, and remove the battery.

[0010] 1A and 1B illustrate an exemplary method 100 for deactivating a lithium-containing battery. It will be understood that various steps of method 100 may be omitted or performed in a different order than that described, and additional steps may be included.

[0011] Referring to FIG. 1A , in some examples, method 100 includes, at 102, breaching the container of a lithium-containing battery to expose the chemicals inside the battery. The battery container may be breached by any suitable method, including using a laser beam, a water jet, mechanically cutting the container open with a shredder, pressure in a reactor, etc. For example, carbon dioxide and oxidizing fluids may have difficulty penetrating some types of batteries (e.g., some types of pouch cells and large automotive cells). In some examples, breaching the battery container may further include disassembling the battery. For example, some lithium nickel cobalt manganese (NCM), lithium nickel cobalt aluminum oxide (NCA) batteries, and jellyroll type batteries have thick and / or closely spaced layers of material. Thus, such types of batteries may be opened, disassembled, and / or unfolded to facilitate passivation.

[0012] Method 100 includes, at 104, adding lithium-containing batteries to a tank. It will be appreciated that in some examples, the batteries may be broken in the tank. For example, some types of batteries (e.g., many prismatic and cylindrical batteries) may not need to be broken before being added to the tank. In some examples, if the batteries are not intentionally broken at 102 before being added to the tank, the batteries may be broken by high pressure (or vacuum exposure) in the tank during inactivation. Advantageously, in some examples, an entire battery pack comprising multiple cells can be processed and inactivated before being disassembled. This may be particularly useful in examples where it is not economically feasible to disassemble and repackage the cells of a battery pack and where handling the battery pack may be dangerous, such as when processing batteries recovered from an electric vehicle involved in a collision.

[0013] The method 100 further includes adding an oxidizing fluid to the bath at 106. In some examples, the oxidizing fluid at 108 includes one or more of water, ammonia, oxygen, ozone, SO2, alcohol, a halogen (e.g., Cl2), and a halocarbon having a boiling point below 150°C. In some examples, the oxidizing fluid may be any suitable liquid or gas capable of donating protons and / or accepting electrons. As an example, water is a relatively simple and readily available oxidizing fluid. Other examples of oxidizing fluids include alcohols (e.g., methanol, ethanol) and other solvents such as halocarbons (e.g., fluorocarbon solvents and / or other halide solvents such as chloroform or CCl4). In some examples, the alcohol or halide solvent used as the oxidizing fluid may have a boiling point below 150°C.

[0014] In other examples, the oxidizing fluid may be a suitable liquid or gas that does not donate protons. As one example, the oxidizing fluid may be ozone gas. In some examples, proton donors may react with the battery electrolyte to produce toxic substances such as hydrogen fluoride. Therefore, an aprotic oxidizing fluid can mitigate the production of such toxic substances. In yet another example, a base such as Li2CO3 can be mixed in combination with the oxidizing fluid to neutralize the electrolyte.

[0015] As shown at 110, one or more additional oxidizers may be combined with the oxidizing fluid for further mixing. Examples include salts (e.g., sodium hypochlorite, lithium hypochlorite, sodium sulfite, lithium sulfite, sodium / lithium / ammonium thiosulfate), peroxides (e.g., hydrogen peroxide, lithium peroxide), ozone, oxygen, or any other suitable oxidizer that is miscible with water or can be otherwise combined with water (i.e., emulsion, solution, etc.) and / or other selected oxidizing fluids. When a chlorine-containing material is used, the final product with an active lithium source may include lithium chloride. When a sulfur-containing material is used, the final product containing lithium may include lithium sulfate or sulfide. Such a passivated lithium product may be a single-phase material or may be a mixture with lithium carbonate, lithium oxide, and / or lithium hydroxide.

[0016] In some examples, the cells are suspended above the surface of the oxidizing fluid, as shown at 112. For example, the cells may rest on an inert object above the bottom of the vessel (e.g., a shelf in an autoclave). In this way, the cells can be exposed to the oxidizing vapors without becoming submerged. Additionally, more of the cells may be exposed to carbon dioxide, which may be immiscible in the oxidizing fluid.

[0017] In another example, the battery may be placed on an active material within the chamber, such as a positive thermal coefficient (PTC) discharge bead. The PTC bead forms a circuit with the battery and can generate heat when current is passed through the circuit. The PTC bead increases in resistance as temperature increases, thereby allowing the reaction system to self-regulate the battery discharge.

[0018] In other examples, the oxidizing fluid may be added to at least partially or completely cover the lithium-containing batteries in the bath with the oxidizing fluid. Fully immersing the batteries in the oxidizing fluid may help ensure that the batteries are fully passivated. Additionally, in some examples, the batteries may be exposed to a flow of the oxidizing fluid, for example, in a continuous flow process.

[0019] The oxidizing fluid may be added to the bath before the batteries are added to the bath, as shown at 114. It will also be appreciated that the oxidizing fluid may be added to the bath after the batteries are added.

[0020] The method 100 further includes sealing the vessel at 116. In some examples, the oxidizing fluid is added before sealing the vessel, as shown at 118. In other examples, the oxidizing fluid may be added after sealing the vessel. For example, the battery may be sealed in a dry vessel, and the oxidizing fluid may be introduced into the sealed vessel via piping.

[0021] At 120, the method 100 includes adding carbon dioxide to the vessel. Any suitable ratio of carbon dioxide to oxidizing fluid(s) can be utilized. For example, as shown at 122, the carbon dioxide and oxidizing fluid(s) may be added in a molar ratio (CO2:oxidizing fluid) between 99:1 and 10:90. In other examples, the molar ratio may be between 98:2 and 10:90. As one illustrative example, the reaction vessel may be filled with a dilute solution of 10% by volume of water or hydrogen peroxide. At 100°C, the vapor pressure of water in the vessel headspace is 1 atm, or approximately 14 psi. The remainder of the reactor is filled with carbon dioxide by piping liquid carbon dioxide into the room-temperature reactor. As described in more detail below, the vessel can be pressurized up to 900 psi with the addition of carbon dioxide so that 90% of the reactor is filled with condensed-phase carbon dioxide.

[0022] In some examples, the carbon dioxide is added separately from the oxidizing fluid, either in a time-overlapping or time-non-overlapping manner. In other examples, the carbon dioxide is added mixed with the oxidizing fluid. Mixing can occur during storage or prior to injection, or can occur during injection. Furthermore, injection of the oxidizing fluid and carbon dioxide can occur through the same nozzle or by different nozzles in various examples.

[0023] Referring now to FIG. 1B, the vessel is pressurized, as shown at 124. At 126, pressurizing the vessel may include forming a condensed carbon dioxide phase. The condensed carbon dioxide phase can take the form of liquid carbon dioxide or dense carbon dioxide gas, in various examples. For example, as shown at 128, the vessel may be pressurized to 500-900 psi. The use of liquid or condensed gas-phase carbon dioxide may offer advantages over the use of supercritical carbon dioxide. For example, the capital equipment costs of equipment to operate with condensed gas-phase or liquid-phase carbon dioxide may be lower than equipment to handle supercritical carbon dioxide. Furthermore, the use of liquid or condensed gas-phase carbon dioxide allows for the use of a higher percentage of water or other reactants in the vessel, which may therefore be mixed (homogeneously or heterogeneously) with the carbon dioxide. However, in some examples, supercritical carbon dioxide may be used.

[0024] In some examples, at 130, the method 100 includes a step of holding for at least 60 minutes after pressurizing the bath with liquid CO2. This holding process can be performed at any suitable temperature. In some examples, the holding step can be performed at temperatures between -55 degrees Celsius (e.g., by adding cryogenic carbon dioxide) and room temperature (e.g., 25 degrees Celsius). The use of cooled carbon dioxide can help prevent thermal runaway of the battery during processing. During this time, the battery is at least partially inactivated and some of the electrolyte may be dissolved. For example, 10-20% of the electrolyte may be dissolved during a 60-minute hold at ambient temperature. In other examples, the initial hold may be performed at a higher temperature or may be omitted. In yet other examples, the hold may be performed in carbon dioxide without an oxidizing fluid, and an oxidizing fluid may be added after the hold process.

[0025] At 132, method 100 includes heating the bath to form lithium carbonate within the lithium-containing battery. As described above, the condensed carbon dioxide phase can help passivate the remaining lithium (e.g., chain lithium) in the battery by forming a lithium carbonate passivation layer that encapsulates the remaining lithium. An exemplary pathway for the formation of lithium carbonate is 2Li + CO → LiO + CO, followed by LiO + CO → LiCO, although the oxidizing fluid can help the carbon dioxide pass through the SEI to reach the lithium. Examples of anode materials that may contain chain lithium and / or other unreacted lithium include graphite-Li, silicon-Li, lithium metal, and various lithium alloys, including tin, aluminum, and the like. While the passivation layer may be formed by CO alone, the addition of water, peroxide, SO, or another suitable oxidizing fluid can aid in the formation of the passivation layer, for example, by increasing the rate of formation and / or the resulting thickness of the passivation layer. The thickness of the passivation layer is estimated to be between 1,300 and 20,000 angstroms, as measured, for example, by impedance spectroscopy.

[0026] In some examples, the bath may be heated to a temperature in the range of 120-130°C, as shown at 134. In other examples, the bath may be set and maintained at a temperature of up to 50-200°C. The bath may be heated for any suitable time to allow the reaction to occur and substantially completely passivate any lithium in the battery, such that the risk of thermal runaway is mitigated. As an example, the bath may be heated for 45 minutes to 2 hours.

[0027] Further, as shown at 136, the contents of the vessel may be held for at least 30-60 minutes after the vessel is heated. In some examples, method 100 may include holding at a first temperature within a temperature range and then ramping to a second, higher temperature. For example, a larger battery (e.g., a 26 Ah cell) may be held at ambient temperature for 20 minutes to 12 hours. The vessel may be held at the first temperature for a longer time and at the second, higher temperature for a shorter time, or vice versa. For example, a 26 Ah cell may be soaked at a lower temperature for 0-12 hours and at a higher temperature (e.g., 120°C) for 0-12 hours. In a typical process, the battery is soaked at ambient temperature for 20 minutes and at the higher temperature for 30 minutes. Longer low-temperature soaks (e.g., cryogenic) may be appropriate for batteries classified as damaged, defective, or having signs of damage and a risk of thermal runaway (e.g., swollen cells, overheating, or an abused system).

[0028] It will be appreciated that the vessel may be heated in any suitable manner. For example, the vessel may be equipped with a jacketed heating system. In other examples, the reactor may be heated by piping in steam and / or hot CO2. Additionally, the vessel may be vented during and / or after heating to maintain a desired pressure (e.g., in the range of 500-900 psi).

[0029] Method 100 further includes reducing the heat and pressure within the bath at 138. In some examples, method 100 includes drawing a vacuum within the bath at 140 to remove the electrolyte material (and any fluids) from the battery (and autoclave). As shown in FIG. 1B, the electrolyte may be extracted after passivating the battery and before removing the battery from the bath. The vacuum may be maintained for any suitable time to extract at least a substantial portion of the electrolyte within the battery, for example, two hours. At 142, the battery may be removed from the bath. It will also be appreciated that one or more steps of method 100 may be repeated before or after removing the battery from the bath. In this manner, the battery may undergo multiple cycles of passivation and / or electrolyte removal.

[0030] Additionally, in some examples, the methods disclosed herein can be useful for stripping electrode materials from the current collectors of the batteries. Figure 2 shows an exemplary method 200 for passivating a lithium-containing battery, which can be useful for stripping electrode materials from the current collectors. The method 200 includes, at 202, rupturing a container for the lithium-containing battery and, at 204, adding the battery to a bath. At 206, the method 200 includes adding water to the bath. In some examples, at 207, an additional oxidizing fluid can be added to the bath. As described above, the oxidizing fluid can include alcohols (e.g., methanol, ethanol), halocarbons (e.g., fluorocarbons), halogenated solvents, and combinations of such fluids. The additional oxidizing agent can be mixed in combination with the oxidizing fluid, such as oxidizing salts (e.g., salts with polyatomic oxidizing anions, such as manganese oxide and chlorine oxide), peroxides, halogens (e.g., chlorine, bromine, or iodine), ozone, and / or any other suitable oxidizing agent miscible with water. Method 200 further includes sealing the vessel at 208 and adding carbon dioxide to the vessel at 210. Method 200 further includes pressurizing and heating the vessel at 212 to form a condensed carbon dioxide phase. The inventors have observed that the addition of a peroxide (e.g., hydrogen peroxide) can aid in delaminating the electrode material from the battery's current collector, for example, by reducing the adhesive strength of the electrode material to the current collector. Thus, in addition to completely passivating a lithium-containing battery, the methods described herein can also aid in more easily recovering the electrode material from the battery for recycling purposes. Such delamination can be performed on electrode assemblies disposed within a battery cell container and / or scrap electrodes removed from the battery container or from the manufacturing line (e.g., defective coatings).

[0031] After deactivation and / or electrolyte removal, the active lithium remaining in the battery can be quantified using methods such as pH titration and triiodide redox titration. As described in more detail below with respect to Figure 4, pH measurements correlate well with the probability of thermal runaway and excessive heat generation.

[0032] For example, in the case of CO2 treatment of LiC6, the passivation chemical reaction is LiC6 + CO2 → 1 / 2Li2CO3 + Li x C6. As x gets smaller, the safety of the material improves. x To quantify C6, Li x C6 is reacted with methanol (or water) to form x equivalents of lithium hydroxide. The lithium hydroxide is titrated with an appropriate acid (e.g., H2SO4) to determine x. Figure 3 shows the reaction of lithium (Li + ) and acid equivalent (H + 1 shows an exemplary plot of the approximately 1:1 relationship between the amount of

[0033] Figure 4 shows a graph illustrating the results of an experiment using pH titration to determine the concentration of active lithium in lithium-containing batteries. Samples were taken from untreated lithium-containing batteries at a fully charged state. Treatments 1 through 3 involve increasing the hold time at 120°C from 0 minutes to 4 hours. The amount of active lithium decreases with treatment time. In these cells, the concentration of active lithium was 20 μmol / cm. 2 No thermal runaway is observed with activated lithium. Figure 4 shows that the untreated charged cell explodes after heating, while treatment 2 achieves deactivation (i.e., the battery does not explode or catch fire when heated with a 500°C heat source).

[0034] In another example, as introduced above, triiodide redox titration can be used to quantify active lithium. For example, lithium triiodide can be formed by reacting lithium iodide with I2. The amount of active lithium can then be quantified using the reaction 2LiC6 + LiI3 → C6 + 3LiI.

[0035] Figures 5 and 6 further demonstrate the resistance of treated batteries to thermal runaway during nail penetration testing. As shown in Figure 5, a nail 702 was used to penetrate the battery housing 704. Figure 5 shows a plot of the temperature profile of a lithium-containing battery during nail penetration testing. Treatment 1: A battery was sealed in a 1 L autoclave containing 100 mL of 3% hydrogen peroxide in water. CO2 was transferred to the autoclave at 900 psi pressure. The system was heated to 120°C in 30 minutes with a 60-minute hold time at 120°C. The pressure was maintained at 2500 psi during the heating and hold periods. The system's heat was then turned off, and the autoclave was cooled to room temperature in 30 minutes while the CO2 pressure was reduced. Treatment 2: 120°C for 120 minutes and 2500 psi during treatment. Treatment 3: 100°C for 17 hours with the pressure reduced to 900 psi during treatment. In a modified nail penetration test for each of these samples, the enclosure of each battery was breached at an initial time of 0 minutes, and the temperature profile of the battery was plotted against the temperature of the battery at the initial time. The untreated battery cells spiked to temperatures up to 1000°C within 2 minutes of penetration at room temperature and pressure. The treated batteries were from the same batch used in Figure 4 above. As shown in Figure 5, the temperature profiles of Treatments 2 and 3 are very similar to that of fully discharged untreated batteries. Fully discharged cells (e.g., short-circuited) generally do not generate heat in the nail penetration test.

[0036] Figure 6 shows plots of the discharge curves of fully charged untreated lithium-containing batteries and treated batteries from the same batch used in Figures 4 and 5. The x-axis shows the battery discharge capacity (mAh), and the y-axis shows the battery voltage. Capacity was measured using a battery cycler from Arbin Instruments, LLC, College Station, Texas, under constant current conditions (e.g., 0.500 amps, C / 4 rate for a cell capacity of 2 Ah), with the cells maintained at 30°C during discharge. As shown in Figure 6, the capacity of the treated batteries decreased. The battery from Treatment 3 had a remaining capacity of approximately 100 mAh. The much lower discharge voltage than the baseline indicates a high internal resistance, consistent with electrolyte removal, along with deactivation and passivation of the carbon-lithium in the anode.

[0037] As introduced above, the method described herein can be used to extract electrolyte from lithium-containing batteries. Figure 7 shows an example gas chromatogram of electrolyte material removed from a lithium-containing battery. The lithium-containing battery was placed in a tank and treated with liquid CO2 without the addition of an oxidizing fluid. The electrolyte was collected as a liquid at the bottom of the tank after the process. A sample of the liquid was analyzed by gas chromatography. As shown in Figure 7, electrolyte material containing ethyl methyl carbonate, ethylene carbonate, and diethyl-2,5-dioxahexanecarboxylate (DEOHC) (a transesterification product of ethyl carbonate or diethyl carbonate) was observed.

[0038] In some examples, the electrolyte salt can react with water to produce HF, which can react with the electrolyte solvent and / or other battery materials to form ionic and non-ionic alkyl-fluorophosphates (e.g., dimethylfluorophosphate and diethylfluorophosphate). Advantageously, the lithium carbonate formed during the process described above with reference to Figures 1 and 2 can neutralize the HF. Ammonium hydroxide, pyridine, lime (a mixture of calcium hydroxide and calcium oxide), or any other suitable base can also be used to neutralize the HF.

[0039] FIG. 8 illustrates an example of a system 800 for extracting electrolyte from a battery. The system 800 includes a CO source 802 configured to provide pressurized carbon dioxide to an extractor vessel 802 via control of a valve 803. The CO source may, in various examples, be configured to provide carbon dioxide in the form of a high-pressure gas, liquid, or supercritical fluid. The carbon dioxide is introduced via piping into vessel 804 to facilitate electrolyte extraction, as described above. After extracting the electrolyte from the battery and / or battery components in the extractor vessel 804, a vacuum is drawn within vessel 804 via control of a valve 806 to remove CO from the extraction vessel and extract the electrolyte from the battery, which is collected in an electrolyte collector 808.

[0040] Lithium carbonate is an exemplary route described herein for the passivation of active lithium in / out of batteries. It will be understood that the passivated oxidized forms of lithium can include oxides, sulfides, halide sulfates, chalcogenides, chalcogenates, nitrogen-group binary salts, or oxoanions of nitrogen-group elements. These end products can be single-phase or passivated mixed products (e.g., lithium sulfate and lithium carbonate). The use of CO2 provides a safe, low-cost, and environmentally friendly industrial route to passivate lithium in or out of batteries.

[0041] Some of the process steps described and / or illustrated herein may be omitted and / or additional steps may be used in some embodiments without departing from the scope of the present disclosure. Similarly, the depicted sequence of process steps is not always necessary to achieve the intended results, but is provided for ease of illustration and description. One or more of the depicted acts, functions, or operations may be performed repeatedly, depending on the particular strategy being used. It will be understood that the above-described articles, systems, and methods are embodiments of the present disclosure and are non-limiting examples, with numerous variations and extensions also contemplated. The present disclosure also includes all novel and non-obvious combinations and subcombinations of the above-described articles, systems, and methods, and any and all equivalents thereof.

Claims

1. 1. A method for deactivating a lithium-containing battery, comprising: adding the lithium-containing battery to a cell; adding an oxidizing fluid to the vessel; adding carbon dioxide to the tank; pressurizing the vessel to form liquid or condensed gas phase carbon dioxide; heating the bath to form lithium carbonate within the lithium-containing battery; reducing the heat and pressure in the vessel; removing the battery from the bath; The method includes:

2. The method of claim 1 further comprising the step of rupturing a container of the lithium-containing battery.

3. 10. The method of claim 1, wherein the oxidizing fluid comprises one or more of water, hydrogen peroxide, ammonia, oxygen, ozone, alcohols, halogens, SO2, and halocarbons having a boiling point less than 150°C.

4. The method of claim 1 further comprising adding the oxidizing fluid mixed with the carbon dioxide.

5. 2. The method of claim 1, wherein adding the lithium-containing battery to the bath comprises suspending the battery above a surface of the oxidizing fluid.

6. The method of claim 1 , wherein the oxidizing fluid is added to the bath before the battery is added to the bath.

7. The method of claim 1 , further comprising adding the oxidizing fluid to the tank separately from the step of adding carbon dioxide.

8. 10. The method of claim 1, wherein the oxidizing fluid and the carbon dioxide are added to the vessel in a molar ratio (CO2:oxidizing fluid) of between 99:1 and 10:

90.

9. The method of claim 1 , wherein the step of pressurizing the vessel comprises pressurizing to 500 to 900 psi.

10. 10. The method of claim 1, further comprising holding the vessel for at least 60 minutes after pressurizing the vessel.

11. The method of claim 1, wherein the step of heating the vessel comprises heating to 120-130°C.

12. The method of claim 1 , further comprising the step of holding the bath for at least 60 minutes after the step of heating.

13. 10. The method of claim 1, further comprising drawing a vacuum within the vessel to remove electrolyte material from the battery prior to removing the battery from the vessel.

14. 1. A method for deactivating a lithium-containing battery, comprising: adding the lithium-containing battery to a cell; adding water to the tank; suspending the battery above the level of the water; adding carbon dioxide to the tank; pressurizing the vessel to form a condensed carbon dioxide phase; heating the bath to form lithium carbonate within the lithium-containing battery; reducing the heat and pressure in the vessel; removing the battery from the bath; The method includes:

15. 15. The method of claim 14, wherein the condensed carbon dioxide phase comprises a gas phase, a liquid phase, a supercritical phase, and / or a dense gas phase.

16. 15. The method of claim 14, further comprising holding the vessel for at least 60 minutes after the step of pressurizing the vessel.

17. 15. The method of claim 14, further comprising the step of holding the bath for at least 60 minutes after the step of heating.

18. The method of claim 14 , wherein the water is added to the bath before the battery is added to the bath.

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