Patent Application
20230387490
The demand for lithium-ion batteries (LiBs) is expected to grow to a large extent in several applications, particularly in connection with electric vehicles (EVs), over the next few years. Driven by rapid technological innovation, increasing environmental and energy concerns, favorable government policies, and growing demand from the renewable-energy sector, this massive conversion is accelerating. At this rate, the demand for LiBs could easily outpace the supply of battery-grade components, such as lithium (Li), cobalt (Co), and nickel (Ni), in the near future. Currently, the supply chain of these critical metals from primary sources reveals a range of risks including political, security, and business risks associated with their geographic concentration. To sustain the growth of the EV market, it is important to secure the source of raw materials.
In the current decade, scraps amounting to up to 10% of the production from gigafactories remain as the primary source of recyclable materials. Despite ongoing efforts in optimizing production lines to reduce such scraps, their quantity can still be significant even when end-of-life (EOL) EV batteries become available for recycling by 2030. The spent batteries that are presently available for recycling are mostly from consumer electronics. Most of these batteries are landfilled or disposed of in some other way because the related environmental regulations have not been fully developed or implemented in many countries. Additionally, they are highly dispersed in small quantities and scattered in different locations. With the coming surge in demand for LiBs in the EV market, the disposal of EOL batteries is expected to ramp up in the next few years. With proactive regulations regarding disposal and collection of spent batteries, recycling of LiB wastes could provide a significant and reliable supply of valuable metals.
Recycling of LiBs involves physical and chemical processes. At the end of their lives, LiBs may be collected and transferred to a recycling facility that employs mechanical separation methods. The batteries are first sorted and discharged to completely drain stored residual energy by known methods, such as using ohmic resistor or cryogenic/inert crushing. Then the batteries are dismantled either manually or by crushing the battery modules in a shredder and/or a mill. The granules thereby generated are sieved to separate material such as steel, plastic, aluminum, and copper from what is commonly referred to as “black mass.”
Chemical pathways for processing black mass include pyrometallurgical and hydrometallurgical processes. Pyrometallurgy employs smelting as the core process step which is similar to that used in smelting of ores. This route presents significant hurdles such as high energy consumption, costly toxic gas treatment, and loss of Li to slag. Moreover, the recovered metals are in forms that are unsuitable for battery production and require additional processing to separate into individual metal compounds.
Most hydrometallurgical processes involve metals recovery by leaching, impurities removal, valuable metals separation, and purification of all the critical metals which entail complex process steps. Typically, the first step is leaching the metals from black mass. A common leaching agent is sulfuric acid (H2SO4) with hydrogen peroxide (H2O2) as the reducing agent. Reduction is required because of the presence of higher valence state species, such as Co3+ and Mn4+, in the black mass, formed during the charging-discharging cycle of the battery. Based on the Eh-pH solution chemistry of the metals, dissolution of higher valence states is lower relative to their lower valence states (Co2+ and Mn2+). Ni and, to some extent, Li are closely associated with Co and Mn; hence, their leaching efficiencies are affected by lower Co and Mn dissolution.
There are a number of studies on processes for recycling of LiB batteries. “A review of recycling spent lithium-ion battery cathode materials using hydrometallurgical treatments” by Jung, J. et al. (2021) and “State-of-the-art lithium-ion battery recycling technologies” by Kaya M. (2022) provide summaries of leaching parameters using reagents in a single-stage process. In most cases, the reaction temperature is higher than 70° C. As temperature increases, acid leaching kinetics are improved. At higher temperature, however, decomposition of H2O2 is faster, resulting in loss and waste of its reductive power. A similar study was published by Prazanova, A. et al., “Literature Review, Recycling of Lithium-Ion Batteries from Electric Vehicles.” There are few process development studies that suggest two-step leaching using different leaching agents in each step intending to preferentially leach Li and Cu in the first step, then the other metals in the second step.
Chabadhiya, K. et al., “Two-step leaching process and kinetics for an eco-friendly recycling of critical metals from spent Li-ion batteries,” refers to a two-step process. In the first step, black mass from spent NMC was leached at 10% pulp density in 0.25M oxalic acid solution, dosed with H2O2 at 80° C. to selectively leach Li and Cu. After filtering the solution, the residue containing Ni, Mn, and Co as their corresponding oxalates was leached in 3M H2SO4 at 6% pulp density, dosed with H2O2 at 60° C. to dissolve Ni, Mn, and Co. There are many drawbacks to employing this process including (1) it requires oxalic acid which is expensive, (2) the recovery of Li from the oxalic acid solution requires solvent extraction, (3) leaching of Ni, Mn, and Co from their oxalate forms requires high acid concentration, (4) the leach solution containing Ni, Mn, Co, and oxalate ions was suggested to be processed via solvent extraction to separate the metals, and (5) the oxalate ions in wastewater may complicate its treatment. Overall, the process may require costly reagents and complex separation process steps which may be avoided in accordance with the present disclosure.
Copper (Cu), iron (Fe), and aluminum (Al) are common impurities in black mass. Cu is from the current collector of the anode, Al is from the current collector of the cathode, and Fe is from the stainless-steel case, all of which can exist as metallic species. The dissolution of Cu and Al metal by H2SO4 gives off two and three electrons, respectively, hence can act as reducing agents. The oxidation potential of H2O2 is above that of the metallic components; therefore, it can also oxidize and dissolve Al and Cu. When H2O2 is added during acid leaching, the metals may be rapidly oxidized resulting in loss of the reductive power of Al and Cu and overconsumption of H2O2. In other words, H2O2 may act as an oxidizing agent in the presence of Al and Cu instead of a reducing agent as intended.
The common impurities such as Fe, Al, and Cu in the leachate containing the valuable metals may be removed by processes such as chemical precipitation, ion exchange, solvent extraction, or combinations thereof. Chemical precipitation utilizes the differences in the solubility of metal compounds which are dependent on pH and temperature. The precipitating reagents that are commonly used are alkali hydroxides or carbonates. “Study on valuable metal incorporation in the Fe—Al precipitate during neutralization of LIB leach solution,” published by Chernyaev, A. et al., reports an investigation at lab-scale of the use of NaOH and LiOH as neutralization reagents for impurities removal, and concluded that the latter resulted in 50% lower co-precipitation of Ni, Co, and Li.
According to “A Novel Closed-Loop Process for Recycling Spent Lithium-Ion Battery Cathode Materials,” published in 2021 by Jung, et al., hydrometallurgical LiB recycling processes commonly use NaOH or sodium carbonate (Na2CO3) for impurity removal, metal extraction, and Li recovery, which results in a final solution containing large amounts of Na ions that potentially complicate the recycling process. To resolve this, the authors propose replacing these reagents with LiOH or Li2CO3 as the reagents. They reported the development of a closed-loop hydrometallurgical recycling process that employs a three-compartment electrodialysis cell for converting waste solutions containing lithium sulfate into pure LiOH and H2SO4 which can be reused.
According to another paper published by another set of authors including Jung in 2022, entitled “Electrodialysis of a Lithium Sulphate Solution: An Experimental Investigation,” such equipment may have a dilute channel filled with a Li2SO4 solution and two concentrate channels separately filled with LiOH and H2SO4 solutions, and the channels are separated by cation-exchange and anion-exchange membranes, respectively. The authors reported high ion recovery ratios of Li+ and SO4− of 94.3 and 87.5%, respectively. The purity of the LiOH solution generated is high. Electrodialysis equipment and auxiliaries can entail high capital expenditures (CAPEX) and the process is highly energy-intensive and requires high maintenance cost, and therefore this is a disadvantageously costly process.
In a known hydrometallurgical processing route, solvent extraction is a process step which enables production of individual battery-grade metal sulfates. An example is referred to in German patent document DE 102018102026 A1 (Hanisch, C. et al.). The described systems are complex, sensitive in operation, and require multiple stages with high degrees of control. They also require effective systems for waste treatment, crud removal, organic vapor emission control, and fire suppression. As such, for implementation of these processes, many pieces of equipment and a large footprint, hence high capital expenditures, are required. Moreover, these processes consume high amounts of reagents, fuel, and electricity.
U.S. Pat. No. 10,995,014 (Fraser, R. J. et al.) attempts to eliminate the separation step and above-mentioned issues by producing mixed metal sulfates. In a first process, the mixed metal sulfate solution is crystallized to generate mixed metal sulfate crystals and a mixed metal sulfate mother liquor. The mother liquor is reacted with a base to form the mixed metal hydroxides, which in turn are used as the reagent in the impurity removal upstream of crystallization. It has been found from experiments related to the present disclosure that, while crystallization of mixed metal sulfate can easily be performed, it is rather difficult to achieve the desired metal ratios. This is because crystallization relies on the solubility of the metal sulfates and each metal sulfate component has different solubilities. Additionally, crystallization is an energy intensive process. After crystallization, the salts are re-dissolved and precipitated as mixed metal hydroxide or carbonate to be used for battery cathode application.
International Patent Publication No. WO 2022/167622 (Mahmood, A. et al.) refers to a process of generating NMC hydroxide for use as a reagent for chemical precipitation of Fe and Al in an impurity removal step. In a co-precipitation process, a purified pregnant leach solution (PLS) is adjusted to pH of 8-9 which causes incomplete precipitation of Ni, Mn, and Co while keeping a portion of those metals along with other impurity ions in solution. After filtering off the precipitates, the solution thereby generated is adjusted to higher pH to completely precipitate the remaining metals as NMC hydroxide. According to WO 2022/167622, using NMC hydroxide as a reagent in the impurity removal step is preferred to avoid introduction of ionic impurities into the PLS. However, the concentrations of Ni, Mn, Co, and Li are governed by their solubility limit at different pH. Ni, Mn, Co hydroxide has low solubility at impurity removal pH 4-5, so by adding more NMC to the solution, the extent of precipitation increases which would lead to higher Ni, Mn, and Co losses.
Disadvantages of the prior art are overcome to a significant extent by the present disclosure.
The present disclosure relates to a method of recovering valuable metals from black mass, where the method includes the steps of acid leaching the black mass in a first stage, to produce acid-leached material, and applying a reducing agent to the acid-leached material in a second stage.
Thus, according to one aspect of the present disclosure, a two-stage leaching process is employed where acid leaching is employed in the first stage and a reducing agent such as H2O2 is added in the second stage. With the benefit of this two stage leaching process, one or more of the following advantages may be achieved: (1) the reductive power of impurity metals such as Cu and Al in the black mass may be taken advantage of; (2) H2O2 consumption may be reduced as a result of its efficient use in the second stage leaching where it is most needed; (3) conditions may be provided where H2O2 only acts as a reducing agent and not as an oxidizing agent; and (4) higher temperature in the first stage can be used to improve acid leaching kinetics and reduce the temperature in the second stage of leaching when H2O2 is added to reduce its decomposition.
The present disclosure also relates to a method of recovering valuable metals from black mass, where the method includes the steps of performing upstream processes on the black mass and using a Li basic solution as a reagent in one or more of the upstream processes.
Thus, according to another aspect of the present disclosure, a Li basic solution is used as a reagent in one or more upstream processes. With the benefit of this aspect of the present disclosure, one or more of the following advantages may be achieved: (1) the use of fresh alkali reagent in impurity removal, ion exchange (IX) resin regeneration, and mixed precipitation may be eliminated; (2) losses of the critical metals to the impurity precipitate during impurity removal by chemical precipitation may be minimized; (3) effective impurity removal by chemical precipitation may be achieved without introduction of a high level of Na that could contaminate the mixed precipitate product or require additional steps of purification (additionally, LiOH has high solubility in acidic pH and will not co-precipitate with impurities or NMC mixed ppt); (4) a Li-containing stream after mixed precipitation may be enriched with Li which minimizes the energy requirement for concentrating the solution prior to Li2CO3 precipitation; and (5) this closed loop process can maximize the recovery of Li.
Moreover, the streamlined process described herein can eliminate an unnecessary metals separation step of the recycling process and the metal sulfates dissolution step of the cathode precursor production. This may result in approximately 60% lower capital cost and 50% lower reagent and utility cost relative to known hydrometallurgical processes where Ni, Mn, and Co are separated, without reducing the quality of the product.
Further, in accordance with another aspect of the present disclosure, there is a process for recovering and purifying Ni, Mn, Co, and Li from black mass obtained from recycling of LiB waste to produce high purity products. The process includes: (i) acid leaching black mass to form an acidic pregnant leach solution (PLS) containing valuable metals such as Ni, Mn, Co, and Li and impurities, and an insoluble material, where the leaching process is a two-stage process including (a) acid leaching with an acid at suitable conditions and (b) reductive acid leaching with a reducing agent at suitable conditions; (ii) separating the acidic PLS and the insoluble material; (iii) adjusting the pH of the acidic PLS using a Li basic solution to form a pH-adjusted slurry including an impurity precipitate containing the impurities and a pH-adjusted PLS containing valuable metals such as Ni, Mn, Co, and Li; (iv) separating the pH-adjusted PLS and the impurity precipitate; (v) removing any residual impurities from the pH-adjusted PLS by adsorption using an ion exchange resin to form the purified PLS containing valuable metals such as Ni, Mn, Co, and Li, where such removing includes (a) eluting the adsorbed impurities from the ion-exchange resin using appropriate eluents and (b) regenerating the ion-exchange resin using the Li basic solution; (vi) adjusting the pH of the purified PLS containing valuable metals such as Ni, Mn, Co, and Li using a Li basic solution to form the mixed precipitate slurry; (vii) separating the mixed precipitate containing Ni, Mn, and Co, and a solution containing Li, where the mixed precipitate can be of high purity (up to battery-grade purity); and (viii) processing the solution containing Li to produce a Li basic solution for use in at least one of above-mentioned steps (iii), (v), and (vi), where the Li basic solution is impure LiOH or Li2CO3 solution.
According to one aspect of the present disclosure, solvent extraction circuits for separation of Mn, Co, and Ni can be advantageously bypassed. Such bypassing may provide a number of advantages, including one or more of the following: (a) reduced equipment cost; (b) reduced building footprint; (c) reduced reagent consumption; (d) reduced waste generation; and (e) improved plant safety.
According to another aspect of the present disclosure, two-stage leaching, including acid leaching followed by reductive leaching, may be employed. Such two-stage leaching may provide a number of advantages, including one or more of the following: (a) increasing Ni, Co, and Li recovery; and (b) reducing H2O2 consumption/reagent cost.
According to another aspect of the present disclosure, a Li basic solution may be used instead of NaOH, which may provide a number of advantages, including one or more of the following: (a) more efficient impurity removal/lower loss of Ni and Co; (b) avoidance of introduction of new impurity; (c) reduction of purification requirements; (d) reduction in the amount of wastewater generated; and (e) increased Li recovery.
Referring now to the drawings, where like reference numerals designate like elements, the present disclosure relates to a process for recovering and purifying Ni, Mn, Co, and Li from black mass 10 (
In the example illustrated in
Further, the process illustrated in
The feedstock to the process (that is, the black mass 10) may be a mixture of cathode and anode materials from recycling of LiB waste or scraps. If desired, the LiB waste or scraps may include at least one of the LiB chemistries lithium iron phosphate (LFP), lithium cobalt oxide (LCO), lithium manganese oxide (LMO), lithium nickel manganese cobalt oxide (NMC), lithium nickel cobalt aluminum oxide (NCA), and lithium titanate (LTO). Further, the black mass 10 may include least one of the valuable metals Ni, Co, Mn, and Li, graphite (C), and at least one impurity such as iron (Fe), aluminum (Al), copper (Cu), phosphorous (P), calcium (Ca), magnesium (Mg), fluoride (F), zirconium (Zr), zinc (Zn), and rare earth elements (REE).
According to one aspect of the present disclosure, the leaching process (S100) is performed in two stages (S102, S104) to efficiently utilize the reducing power of Al and/or Cu metals and prevent overconsumption of H2O2. Firstly, the feedstock is mixed with acidic solution (S102) to dissolve at least a portion of Ni, Mn, Co, Li, and impurities. Suitable acids may include, but are not limited to, mineral acids including sulfuric acid, hydrochloric acid, and nitric acid. The amount of acid to be added may be more than the stoichiometric amount required to completely dissolve the Ni, Mn, Co, and Li, and impurities. The leaching may be carried out at a temperature equal to or less than the boiling point of the slurry, while the slurry is thoroughly mixed. A portion of at least one Ni, Mn, Co, and Li is dissolved in solution. The relatively low leaching efficiency of particularly Co and Mn are due to the formation of higher valence state species, such as Co3+ and Mn4+, during the charging-discharging cycle of the battery. Based on the Eh-pH solution chemistry of the metals, dissolution of higher valence states is lower relative to their lower valence states (Co2+ and Mn2+). Ni and, to some extent, Li are closely associated with Co and Mn; hence, their leaching efficiencies are affected by lower Co and Mn dissolution.
Then (after S102), the acidic slurry from the first stage of acid leaching may be cooled to a temperature suitable for an efficient reaction with the reducing agent (S104), preferably about 60-70° C. to reduce the rate of H2O2 decomposition. The reducing agent may include, but is not limited to, H2O2, sulfur dioxide, sodium bisulfite, or sodium metabisulfite. The amount of the reducing agent may be more than the stoichiometric amount required to reduce the oxidized valuable metals particularly Co3+ to Co2+ and Mn4+ to Mn2+ while the solution is thoroughly mixed. Any undissolved valuable metals and impurities may be partially present in the insoluble material. Separation (S106) of the acidic PLS and the insoluble material 14 may be accomplished by known methods such as gravitational settling, decantation, filtration, centrifugation, or any other appropriate method.
The insoluble material 14 may contain graphite and may be further purified and regenerated to form a saleable (marketable) product or reused in the process as adsorber for organics.
In operation, the acidic PLS containing Ni, Mn, Co, and Li, and impurities may be added with a suitable alkali reagent to precipitate at least a portion of one or more impurities including, but not limited to, Al, Cu, Fe, P, and Zr. Li basic solution 16 can be preferentially used to reduce the introduction of impurities that could occur when using other alkali reagents such as NaOH, Na2CO3, calcium hydroxide, potassium carbonate (K2CO3), potassium hydroxide (KOH) or costly reagents such as Li2CO3, or LiOH. The pH-adjusted slurry 18 that is formed includes an impurity precipitate 22 and a pH-adjusted PLS 20 containing Ni, Mn, Co, and Li, and residual impurities which may be separated by suitable methods such as gravitational settling, decantation, filtration, centrifugation, or any other appropriate method.
If desired, the residual impurities in the pH-adjusted PLS 20 may be removed by ion exchange (S112) using a suitable ion exchange resin. The removal of residual impurities, particularly Al and Cu, from the pH-adjusted PLS may be completed without significant co-adsorption of Ni, Mn, Co, and Li. The adsorbed impurities may be eluted from the resin by suitable eluents. The eluted resin may be regenerated by an alkali reagent in solution form. The regenerant can be the Li basic solution 16 containing Li from the process to reduce introduction of new impurities to the solution. The regenerated resin may be reused.
The recovery of valuable metals such as Ni, Mn, and Co from the purified PLS may be performed by adjusting the pH using an alkali reagent. The alkali reagent may be Li basic solution 16 to reduce the introduction of impurities that would have been introduced at high levels by using other basic reagents such as Na2CO3, K2CO3, NaOH, or KOH or by using other alkali reagents such as Li2CO3, or LiOH that are costly. When an alkali carbonate is used, the pH of precipitation may be at least 6 and up to 9, or at least 6.5 and up to 8.5, or at least 7 up to 8, whereas when an alkali hydroxide is used, the pH of precipitation may be at least 7 and up to 13, or at least 10.5 and up to 12.5, or at least 11 and up to 12.
If desired, the precipitation (S114) may be carried out at a temperature equal to or less than the boiling point of the slurry while the slurry is thoroughly mixed. The mixed or co-precipitation process may be in batch or continuous mode. Optionally, the precipitation may employ a co-precipitation process using a chelating agent such as ammonium hydroxide. The mixed precipitate slurry that is formed includes a mixed precipitate 24 containing Ni, Mn, and Co, and a solution containing Li, which can be separated by suitable methods (S116) such as gravitational settling, decantation, filtration, centrifugation, or any other appropriate method.
The solution containing Li may be further processed (S118) to recover Li basic solution 16 to be used as a reagent for at least one of the frontend processes illustrated in
The following examples (Comparative Tests 1 and 2) are illustrative of processes in accordance with the present disclosure:
Comparative Test 1: Two-Stage Leaching—Acid Leaching Followed by Reductive Leaching, Compared with Single-Stage Leaching where Acid Leaching and Reduction Take Place Simultaneously.
A black mass sample 1 having the composition shown in Table 1 was considered in the comparative leaching tests. The leaching was done in an 800-mL beaker using an overhead agitator and an electrically heated hotplate. The reagents used were analytical grade 98% wt H2SO4 from Merck and industrial grade 50% wt H2O2 solution. About 50 g of the black mass on dry basis was used in each test parameter employed. The amount of H2SO4 was 20% in excess of the stoichiometric requirement to form corresponding sulfates of Ni, Co, Mn, Li, Al, Cu, and Fe. The amount of H2O2 used was the same for each case.
For the two-stage leaching, the black mass was first leached in H2SO4 solution at 80-90° C. for 2 hours. A sample of the slurry was taken for analysis to determine the quantity of metals, particularly Co and Mn, left in the residue. The amount of H2O2 was calculated based on amount of residual Co and Mn. The acid-leached slurry was cooled to 55-65° C. in preparation for the reduction step. H2O2 was added into the slurry via a peristaltic pump at a rate of 1 mL/min.
For the one-stage leaching, the black mass was leached in a solution of H2SO4 and H2O2 at two different temperatures for 2 hours. The same amount of H2O2 as calculated in the two-stage leaching was used. A sample of the slurry was taken for analysis.
All samples were filtered using Whatman 41. The solutions and residues were prepared according to established procedures and analyzed using Agilent 5110 ICP-OES.
The relatively low leaching efficiency of Co and Mn in Stage 1 is attributed to the presence of higher valence state species, including Co3+ and Mn4+, from the charging-discharging cycle of the battery. The solubility of these higher valence states is lower relative to their lower valence states (Co2+ and Mn2+). Ni and, to some extent, Li are closely associated with Co and Mn; hence, their leaching efficiencies can be affected. At the same time, Al, Cu, and Fe can be present in the black mass as metals, and their dissolution by the acid releases corresponding electrons that can reduce Co3+ and Mn4+, according to the half-cell reactions shown in Table 2.
Known leaching systems for black mass are performed in a single step, that is, the black mass is reacted with the mixture of the lixiviant and the reducing agent. Shown in Table 1, when one-step reductive acid leaching is done, the extent of leaching of particularly Co and Mn were lower at the same amount of H2O2 used in the two-stage leaching given the overall same amount of reaction time.
The one-step leaching system at 80-90° C. could have suffered either or both of the following causes of inefficient use of H2O2. With high temperature, the rate of decomposition of H2O2 is very fast. Also, H2O2 can act as both a reducing agent and an oxidizing agent in the leaching system. Having an oxidation potential above that of Al, Cu, and Fe (including Fe2+ which also holds a reductive power), it can rapidly react with and oxidize the metals. Therefore, when H2O2 is added in one step with the acid, the reductive power of the metals would not be utilized by Co3+ and Mn4+, which in turn can result in unnecessary over-consumption of H2O2. The latter cause could be more prevalent in one-step leaching systems at lower temperature.
Comparative Test 2: Impurity Removal by Chemical Precipitation Using NaOH and Li Basic Solution
An objective of the impurity removal via chemical precipitation step (see
Comparative Test 3: Mixed Metal Precipitation Using NaOH and Li Basic Solution
An acidic PLS with total Ni, Mn, and Co concentrations [TM] of 1 molar obtained by leaching black mass sample 1 was prepared. The PLS was split into two parts. The first part went through impurity removal, and mixed precipitation steps using Li basic solution. The second part used NaOH. All parameters such as agitation, temperature, rate of addition, reaction time, and pH were the same for both tests.
The precipitates generated were washed with the same amount of deionized water. The washing was collected and measured for conductivity using Thermo Scientific Orion A Star Conductivity Meter and analyzed for Na and Li to monitor the extent of washing. The results are shown in Table 3.
The required amount of water to wash the precipitate to reach the same level of Na impurity was significantly higher in the test where NaOH was used as a precipitating agent. It was estimated that by using Li basic solution, there would be at least 50% reduction in evaporation duty of wastewater. In effect, this also means relatively smaller equipment capacity requirement and lower energy consumption.
The results in Table 3 show that in the presence of a high concentration of Li, mixed Ni, Mn, and Co precipitate was produced with minimal amount of Li. A study by Jo, M. et al. (2018), “Effects of Residual Lithium in the precursors of Li[Ni1/3Co1/3Mn1/3]O2 on their lithium-ion battery performance,” reported the involuntary introduction of Li to the precursors during co-precipitation of Ni, Mn, and Co in the presence of Li in solution. Jo, M. et al. observed undesirable cation mixing with the increasing Li content of the precursors. The results in Table 3 show that inclusion of Li in the mixed precipitate can be minimal by applying parameters according to the present disclosure even in the presence of high concentration of Li. It is believed that by applying the process parameters of the present disclosure, almost all Li is adsorbed on the surface of particles rather than inserted into the crystal structure which can be removed by washing.
Test 4. Processing of Black Mass Sample 1
A process in accordance with the present disclosure was tested on a sample of black mass from acid leaching to mixed precipitation. About 225 g of the black mass sample 1 having the composition shown in Table 4 was leached via the above-described two-stage leaching (see
The Li-containing solution was processed to produce Li2CO3 and Li basic solution.
As shown in Table 4, the mixed metal precipitate produced in Test 4 has a similar composition as the infeed in terms of metal ratios. As a result, the mixed metal precipitate can be advantageously employed directly in the production of a cathode precursor. Fe, Al, and Cu concentrations in the purified solution and the mixed precipitate are low. The Na and Li contents are within an acceptable range according to known specifications. In these experiments, Ni, Mn, and Co concentrations were not adjusted. Alternatively, the concentrations can be adjusted to reach the desirable Ni:Mn:Co.
Test 5. Processing of Black Mass Sample 2
The same procedure as in Test 4 was employed in the processing of black mass sample 2. The results are shown in Table 5.
As used herein, unless otherwise specified, all numbers such as those expressing values, ranges, amounts or percentages may be read as if prefaced by the word “about,” even if the term does not expressly appear. Any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, a range of “1 to 10” is intended to include any and all sub-ranges between and including the recited minimum value of 1 and the recited maximum value of 10, that is, all subranges beginning with a minimum value equal to or greater than 1 and ending with a maximum value equal to or less than 10, and all subranges in between, e.g., 1 to 6.3, or 5.5 to 10, or 2.7 to 6.1. Plural encompasses singular and vice versa. When ranges are given, any endpoints of those ranges and/or numbers within those ranges can be combined within the scope of the present disclosure. “Including,” “such as,” “for example,” and like terms means “including/such as/for example but not limited to.”
The methods recited in the claims which follow should not be limited by the order in which steps are listed.
This application claims priority to U.S. Provisional Patent Applications Nos. 63/365,422 and 63/368,396, filed May 27 and Jul. 14, 2022, respectively. This application is a continuation-in-part of, and claims the benefit of, U.S. patent application Ser. No. 17/804,337, filed May 27, 2022. The entire disclosures of U.S. Provisional Patent Applications Nos. 63/365,422 and 63/368,396 and U.S. patent application Ser. No. 17/804,337 are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63365422 | May 2022 | US | |
| 63368396 | Jul 2022 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17804337 | May 2022 | US |
| Child | 18323631 | US |
