Process for recovery of battery cathode metal oxides from the end-of-life batteries using copper and iron

Abstract

A process for lithium-containing transition metal oxide material based recovery of anyone or more of transition metals and lithium therefrom including from recycling of battery cathode oxide compounds, is provided with the help of copper and iron in said process. Said process comprising of the following steps; (i) reductive leaching of the black mass using copper as the reductant, (ii) cementation (or regeneration) of the copper using the iron powder, (iii) oxidation of Fe2+ and precipitation of the iron oxide / hydroxide used by adding the black mass, (iv) regeneration of iron powder.

Description

[0001] PROCESS FOR RECOVERY OF BATTERY CATHODE METAL OXIDES FROM THE END-OF4JFE BATTERIES USING COPPER AND IRON

[0002] FIELD OF THE INVENTION

[0003] The present invention provides for a process for lithium-containing transition metal oxide material based recovery of anyone or more of transition metals and lithium therefrom particularly said process including recycling of battery cathode oxide compounds, with the help of copper and iron in said process. The present invention is particularly related to recycling of battery cathode oxide materials from end-of-life batteries using copper and iron.

[0004] Said process comprising of the following steps: (i) reductive leaching of the black mass using copper as the reductant, (ii) cementation (or regeneration) of the copper using the iron powder, (iii) oxidation of Fe2+and precipitation of the iron oxide / hydroxide used by adding the black mass, (iv) regeneration of iron powder.

[0005] BACKGROUND OF THE INVENTION

[0006] Lithium-ion batteries are widely populated in the world because of their extensive applications in the energy storage sectors and electronic appliances. There are various types of lithium-ion batteries available in the market with different compositions like LiCoOi, LiMn2O4, LiNi0.3Co0.15Al0.05O2, LifNio.3Coo.1Mno.1JO2, etc. Among these most of the ingredients are concentrated in a few countries. To avoid monopoly and circular economy people looking for technologies to recycle the spent batteries. Recycling the batteries also solves problems associated with environmental pollution related to solid waste disposal.

[0007] The currently available pyro and hydrometallurgical process routes for battery recycling have demerits like feedstock limitations, high energy consumption, the use of costly and inefficient reductants like H2O2 and SO2, etc. Hence, it is necessary to develop an economical, robust, and environmentally friendly process to overcome these problems.

[0008] Ghassa et.al. (Resource Conservation and Recycling, 166, (2021), 105348) studied the dissolution of black mass in presence of metallic iron as a reductant. Use of iron directly as a reducing agent has a major issue as it first converts to Fe2+by liberating hydrogen. Furthermore, the authors used both H2O2 and NaOH for the precipitation of iron oxide / hydroxide. This process consume high amount of iron and also consumes reagents and generate solid residues and effluents.

[0009] Therefore requirement of an alternative process for the recovery and purification of battery cathode metal oxides from spent lithium ion batteries or production waste including wastes of lithium-containing transition metal oxide material and recovery therefrom of anyone or more of transition metals and lithium therefrom, is needed through and by exploring an energy-efficient technique for recycling of Lithium Ion Batteries.

[0010] OBJECTS OF THE INVENTION

[0011] It is thus the primary objective of the present invention to develop a process for the recovery of lithium and other metals from spent lithium ion batteries or production waste containing at least one of the transition metals nickel, manganese and cobalt through an energy-efficient and cost-effective technique.

[0012] Another objective of the present invention is to develop a process for the recovery of lithium and other metals by an indirect reductive leaching with iron as a reducing agent and copper as an intermediate reductant.

[0013] It is another objective of the present invention to provide a process for the recovery of lithium and other metals by avoiding the usage of unstable and expensive H2O2 as a reductant and instead involving more economical reductant to reduce the trivalent state of the transition metals to divalent state, such as Fe to reduce cost thus enabling more economic process compared to the existing techniques which require expensive reagents.

[0014] SUMMARY OF THE INVENTION Thus according to the basic aspect of the present invention there is provided a process for lithium-containing transition metal oxide material based recovery of anyone or more of a transition metals and lithium therefrom comprising:

[0015] (a) subjecting the lithium-containing transition metal oxide material to a step of acid based reductive leaching initially in the presence of copper as an intermediate reductant prior to addition of any iron reductant;

[0016] (b) thereafter carrying out cementation / removal of copper (II) by addition of iron;

[0017] (c) oxidation of dissolved Fe (II) generated in step (b) above for precipitation as iron (III) oxide / hydroxide to thereby provide for solution pregnant with salt / s including Li, Co, Mn and Ni salt / s for recovery therefrom of the desired anyone or more of Li, Co, Mn and Ni.

[0018] Preferably in said process for lithium-containing transition metal oxide material based recovery said lithium-containing transition metal oxide material include lithium-ion batteries, spent batteries, waste battery material from production, off- spec material, and other materials containing lithium and transition metals including Ni, Co, Mn.

[0019] According to a preferred aspect of the present invention there is provided a process for lithium-containing transition metal oxide material based recovery enabling recovery from and recycling of battery cathode oxide compounds from spent batteries with the aid of said both copper and iron as reluctant wherein said step (a) involves subjecting said lithium-containing transition metal oxide material as cathode material compound based first portion of black mass to reductive leaching by involving copper (0) as intermediate reductant; said step (b) involves cementation / removal of copper (II) by selectively involving alternative iron (0) as reductant that gets converted to Fe (II); said step (c) involves oxidation of dissolved Fe (II) attained out of step (b) for precipitation of iron (III) oxide / hydroxide by selectively involving second portion of black mass based cathode material followed by regeneration of iron / iron removal to obtain therefrom said solution pregnant with salt / s including Li, Co, Mn and Ni salt / s recoverable by solvent extraction, precipitation and / or crystallization.

[0020] Preferably a process is provided for said recovery and recycling of battery cathode oxide compounds as critical metals from cathode of spent batteries including from lithium ion batteries containing lithium and at least one of the transition metals: nickel, manganese and cobalt wherein said step (a) involves said subjecting said cathode material compound based first portion of black mass to reductive leaching in presence of copper (0) as said intermediate reductant in excess of stoichiometric amounts and organic / mineral acids including H2SO4 to obtain a leached slurry adapted for solid-liquid separation resulting in clear solution containing Li, Ni, Co, Mn, and / or oxidized Cu(II) in said clear solution; said step (b) involves cementation / removal of copper (II) from said leached slurry based clear solution as Cu (0) by addition of iron (0) as said alternative reductant at pH <5 with iron (0) in turn getting converted to dissolved iron (II) that is followed by solid-liquid separation to precipitate / remove Cu (0) that is recyclable to step (a); said step (c) involves removing said dissolved iron (II) from said leached slurry solution of step (b) by adding said second portion of black mass based cathode material after adjusting pH to >2 for converting iron (II) to ferric iron hydroxide / oxide to facilitate iron removal from solution pregnant with ions including ions of Li, Co, Mn and Ni salts and recoverable by solvent extraction, precipitation and / or crystallization. According to a preferred aspect of the present invention there is provided said process wherein utilizing copper (0) as an intermediate reductant is involved in Stoichiometric to 20% excess of stoichiometric amount prior to involving iron (0) as reductant causes reduced consumption of iron that is reduced to one-third compared to when iron is directly employed as reductant.

[0021] Preferably in said process wherein said cathode material compound based black mass is derived from including lithium-containing transition metal oxide material originating from various sources of lithium-ion batteries, including spent batteries, waste battery material from production, off-spec material, and other materials including lithium and transition metal / s M= including Ni, Co, Mn, and representable by chemical formula LiMCh or LioO.MoCh with said transition metal in trivalent state that is dissolvable in acidic solution based on involving copper (0) as intermediate reductant towards bringing said transitional metal to divalent state, as compared to conventional H2O2, SO2 reductants employed for energy intensive high temperature reductions.

[0022] More preferably a process is provided wherein said cementing of Cu (0) by involving iron as alternative reluctant includes iron powder, iron components, iron scrap, sponge Iron (Direct Reduced Iron) or any iron containing alloys / intermetallic s.

[0023] According to yet another preferred aspect of the process of the present invention wherein said step (b) of cementation / removal of Cu (0) is conducted within a temperature range of room temperature to upto 100°C, within a duration of 5 minutes to 12 hours at pH < 5, preferably < 3, to prevent copper hydrolysis, which cemented copper (0) is separated by solid-liquid separation for re-use in step (a). Preferably said process is provided wherein said step (c) of iron (II) oxidation for precipitation of iron (III) oxide / hydroxide is carried out by said second portion of black mass based cathode material conducted within a temperature range of room temperature to 100°C, with a duration of 5 minutes to 12 hours and at pH >3 for removal / precipitation of iron (III) oxide / hydroxide from solution.

[0024] According to yet another preferred aspect of the process of the present invention wherein said post removal / precipitation of iron (III) oxide / hydroxide from solution in step (c), iron (0) is regenerated from iron (III) hydroxide / oxide by reduction with hydrogen / hydrocarbons / carbohydrates / carbon / coal / coke / charcoal / graphite from anode at temperatures from 400-1200 °C, which iron (0) is reusable for cementation of copper (0) from solution.

[0025] Preferably said process is energy intensive and avoids expensive reductants including H2O2, SO2, organic reductants and yet enhances efficiency of reductive leaching of higher oxides present in said black mass with the leach solution obtained after iron removal step being free from impurities such as Cu, Fe and organic reductants whereby more than 98% of Li and transition metals are recoverable from said black mass based battery cathode material.

[0026] More preferably a process is provided wherein said cathode material compound based black mass is derived from sources including lithium-containing transition metal oxide material originating from various sources of lithium-ion batteries, including spent batteries, waste battery material from production, off-spec material, and other materials including lithium and transition metal / s M= including Ni, Co, Mn, derived by including following steps: (i) Discharging the batteries in salt solution followed by shredding; (ii) dismantling by varied physical separation process including sieving, froth flotation, magnetic separation. According to yet another preferred aspect of the present invention said copper reductant includes copper scrap, PCBs, copper powder, copper sheets from Li-ion battery or copper containing metal / alloys.

[0027] In one aspect in a mixture of cathode and anode fraction, graphite can be selectively separated by treating the mixture with an ammonia and ammonical solution, where graphite is selectively removed from the anode and separated by classification. After removal of graphite, cathode material can be recovered by conventional process.

[0028] In an another aspect, the black mass from the battery from aforementioned process or from conventional route is leached into the acid solution composed of acid (inorganic or organic acid), water, and copper as a reductant. During the leaching, the operational parameters such as pH, temperature, and time are maintained in a range of 0 to 4, 0°C to 100°C, and 5 min to 12 h respectively.

[0029] In another aspect, the copper from the leach liquor was cemented using iron powder / scrap / sponge iron (DRI) or any other zero-valent iron containing materials including scraps as the cementing agent.

[0030] The black mass is added to the leach liquor to oxidize the iron (II) presented to precipitate as iron (III) oxide / hydroxide.

[0031] After conventional purification of the leach solution, the elements like Co, Ni, Mn, etc. (except lithium) were recovered from the solution by conventional processes such as crystallization, solvent extraction and / or by pH precipitation.

[0032] After recovering Ni, Co and / or Mn, the lithium present in the solution was precipitated as lithium carbonate by adding the sodium carbonate.

[0033] The iron can be regenerated from iron (II) hydroxide / oxide by addition of hydrogen / hydrocarbons / carbohydrates / carbon / coal / coke / charcoal / graphite from the anode at temperature from 400-1200 °C and it can be reused in for cementation of the copper from solution.

[0034] BRIEF DESCRIPTION OF FIGURES

[0035] Figure 1: Process Flowsheet; Figure 2: XRD Of Cemented Cu;

[0036] Figure 3: XRD Of iron hydroxide (Geothite);

[0037] Figure 4: XRD Of Reduced iron hydroxide (Goethite).

[0038] DETAILED DESCRIPTION OF THE INVENTION AND ITS VARIOUS NON-LIMITING EMBODIMENTS

[0039] As described hereinbefore, the present invention is directed towards a process for the recovery of lithium and other metals from spent lithium-ion batteries or production waste containing at least one of the transition metals nickel, manganese, and cobalt, said process particularly pertaining to reductive leaching of cathode material with copper, cementation of the copper using the metallic iron, removal of dissolved ferrous iron in the form of ferric hydroxide / oxide with the addition of black mass.

[0040] The cathodic material or black mass can be reclaimed through a conventional process. In the present method, ammonia and an ammonical solution are used to selectively remove graphite from the anode. This solution etches the copper surface, causing the graphite to detach and allowing for its subsequent removal through classification. Once the graphite has been successfully removed, the cathode material can be separated using dissolution, pyrolysis, or any other established conventional techniques.

[0041] The black mass is composed of Li, Co, Ni, Mn, etc materials some of which do not dissolve in normal leaching conditions. Hence, a reducing agent supply must be necessary to dissolve these elements along with the acid. In the present case, the copper obtained from the anode is used as the reducing agent.

[0042] The present invention encompasses a process consisting of several steps, referred to as step (a), step (b), step (c), etc., which are described in greater detail below.

[0043] As per the primary objective of the present invention, the process is directed to recover one or more transition metals and lithium as Li- salt from a material containing waste lithium-ion batteries. The process involves the following steps: (a) Leaching the cathode material (black mass) with mineral or organic acids in the presence of metallic copper. This step aims to reduce the transition metals (such as Ni, Co, Mn) present in the cathode material from a higher oxidation state to a 2+ state. The undissolved solids after leaching are separated by subjecting them to a solid-liquid separation process to recover the pregnant solution.

[0044] (b) Treating the pregnant solution obtained from step (a) with iron to remove or precipitate the copper from the solution.

[0045] (c) Removing the dissolved iron from the solution by converting it to ferric hydroxide / oxide. This is achieved by adding black mass and adjusting the pH to a value greater than 3.

[0046] The black mass utilized in step (a) is derived from lithium-containing transition metal oxide material, which may originate from various sources such as lithium- ion batteries, including spent batteries, waste battery material from production, off- spec material, and other materials containing lithium and the mentioned transition metals (Ni, Co, Mn, etc.).

[0047] The black mass consists of Lithium and transition metals (M) represented by the chemical formula LiM02 or Li2O.M2O3. The transition metal in this material exists in a trivalent state, which makes it challenging to dissolve fully in an acidic solution. Therefore, in conventional methods, the transition metal is typically reduced to a divalent state before leaching through high-temperature reduction or with the assistance of a reducing agent like H2O2, SO2, etc., as depicted in the following chemical reaction.

[0048] Li2O.M2O3+H2 / C / CO / CxHy / CxHyOz= Li2O / Li2CO3+MO / M +CO / CO2 / H2O — (1)

[0049] Li2O.M2O3+H2O2+H2SO4= Li2SO4+2MSO4+H2O —(2)

[0050] The conventional high-temperature reduction mentioned above is an energy- intensive process, and the reductive leaching method necessitates expensive reagents or involves multiple processing steps. Moreover, the use of H2O2 as a reducing agent poses challenges due to its unstable nature, leading to increased consumption during the process. Scrap iron / iron powder can be used as an alternative reductant. However, the efficiency will be low as the metallic Fe dissolves in the leach solution without completely participating in the reduction of the trivalent transition metals to divalent state by liberating hydrogen gas according to the following chemical equation.

[0051] 2Fe +2H2SO4= 2FeSO4+2H2—(4)

[0052] H2SO4 + 2FeSO4+2LiMO2= Fe2O3+ Li2SO4+ 2MSO4-—(5)

[0053] However, the consumption of iron can be decreased by using copper as an intermediate reductant, as copper is above the hydrogen line in EMF table. Hence, copper was used as a reductant in the step (a).

[0054] Li2O.M2O3+Cu +4H2SO4= Li2SO4+2MSO4+CuSO4+4H2O —(6)

[0055] Step (a) of the current process, illustrated in Figures 1, involves leaching the black mass with mineral / organic acids in the presence of copper at temperatures ranging from 0 to 100°C for a duration of 5 minutes to 12 hours. Subsequently, a solidliquid separation is performed to eliminate any undissolved materials, if present, resulting in a clear solution containing Li, Ni, Co, Mn, and / or Cu.

[0056] The reactions that occur in the leaching stage (step (a) can be rewritten as;

[0057] Li2O + H2SO4 = Li2SO4+ H2O

[0058] (Co,Ni,Mn)2O3+ 3 H2SO4+ Cu = 2 (Co,Ni,Mn)SO4+ CuSO4+ 3 H2O

[0059] Step (b) involves the removal or regeneration of copper from the leach solution obtained in step (a) [Figure 1]. It is necessary to eliminate the copper from the leach solution before recovering other transition metals, as this step is crucial for obtaining pure Ni, Co, and Mn salts, compounds, or metals from the solution. However, achieving complete removal of copper from the leach solution can be challenging and may result in an increased number of process steps for recovering other transition metals, thereby making the overall process more expensive.

[0060] The copper present in the leach liquor is cemented as pure copper by adding iron in the form of iron powder, iron components, iron scrap, sponge Iron (DRI) or any iron containing alloys / intermetallics to it. The copper recovered can be reused in the leaching process. The reaction is expressed as follows;

[0061] CuSO4+ Fe = FeSO4+ Cu

[0062] The cementation process in step (b) can be conducted within a temperature range of room temperature to 100°C, with a duration of 5 minutes to 12 hours. It is important to carry out the cementation step at a pH below 5, preferably below 3, to prevent copper hydrolysis. Following cementation, the copper can be separated through a solid-liquid separation step. The cemented copper obtained can be reused in step (a), thus ensuring its utilization within the process.

[0063] In step (c), the dissolved iron sulfate is oxidized and precipitated as iron (III) oxide / hydroxide with the addition of the black mass and this step was conducted within a temperature range of room temperature to 100°C, with a duration of 5 minutes to 12 hours. It is important to carry out the cementation step at a pH above 3 for the removal of iron from the solution, which is shown in the following reaction.

[0064] 2 Fe(II)SO4+ 2 Li(Co,Ni,Mn)O2+ H2SO4= 2 Fe(III)OOH + Li2SO4+ 2(Co,Ni,Mn)SO4

[0065] By utilizing copper as an intermediate reductant, the consumption of iron can be reduced to one-third compared to when iron is directly employed as a reductant.

[0066] After iron removal, the solution containing other impurities are removed by conventional processes. After solution purification, the pregnant solution contains mainly Li, Co, Mn and nickel salts. Ni, Co, Mn, and Li can be recovered by traditional processes such as solvent extraction, precipitation and / or crystallization.

[0067] The iron can be regenerated from iron(III) hydroxide / oxide by reduction with hydrogcn / hydrocarbons / carbohydratcs / carbon / coal / cokc / charcoal / graphitc from the anode etc. at temperature from 400-1200 °C and it can be reused for cementation of the copper from solution.

[0068] Fe2O3 / FeOOH+C = 2Fe+CO / CO2+H2O

[0069] The invented process of the present invention also decreases the energy consumption by decreasing the amount of material needed to be processed at high temperatures. This process also avoids expensive reductants such as H2O2, SO2, organic reductants etc. Furthermore, this process increases the efficiency of reductive leaching of higher oxides present in the black mass. The leach solution obtained after iron removal step is free from impurities such as Cu, Fe and organic reductants. More than 98% of Li and transition metals can be recovered from the black mass by this process.

[0070] WORKING EXAMPLES:

[0071] The advantages and benefits of the present process according to the embodiments of the present invention would become more apparent from the below experimental details to a person skilled in the art.

[0072] EXAMPLE 1:

[0073] 2g NMC black mass along with 10% excess to the stoichiometric amount of (0.70 g) Cu powder and 10% excess of stoichiometric amount (4.4g) H2SO4 was added to 24.56 ml of distilled water and stirred for 4 hours at 70°C and 600 rpm. The leach liquor contained dissolved sulfate compounds. The pH of the leached solution was 1.19 and the ORP was 416 mV. The solution was then filtered. The weight of the residue was ~ 0g. 0.63 g Fe was added to the Cu leaching leach liquor to cement out Cu at 50°C, 300rpm for 30 minutes. The solution was filtered and the cemented Cu residue was weighed which came out to be 0.62 g. The black mass (1 g, 0.3g H2SO4) was added to the filtered solution obtained after Cu cementation to precipitate iron as Geothite / Iron Hydroxide which weighed 1.24g. The acid was gradually added in 8 intervals to prevent the formation of jarosite. The iron oxide / hydroxide recovered was mixed with activated charcoal and heated to 900°C for 1 hour to produce iron. The weight of the residue Fe was 1.13g. The XRD of the iron shows the presence of iron and magnetite. However, the condition such as temperature and time, reductant amount can be optimised to complete rely convert iron oxides to iron metal. This iron can be reused in the process for copper cementation. EXAMPLE 2:

[0074] The anode of the battery, Cu foil coated with graphite was stirred in an ammonical solution for easy detachment of graphite from the Cu foil, it was further cleaned properly with distilled water to remove traces of graphite. Then the Cu foil was cut into 1cm X 1cm sheets to be used as reductant for leaching process. 2 g NMC black mass alongwith 20% excess of stoichiometric amount of (0.764 g)Cu sheets and 20% excess of stoichiometric amount (4.8 g) H2SO4 was added to 25ml of distilled water and stirred for 4 hours at 70°C and 600 rpm. The leach liquor contained dissolved sulfate compounds. The pH of the leached solution was 2.22 and the ORP was 375 mV. The solution was then filtered. Weight of the residue was ~ 0g.

[0075] The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application thereby enabling others, skilled in the art, to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated.

[0076] Advantages obtained by the process of the present invention: i) The high-temperature reduction process employed to reduce iron oxide consumes less energy in comparison to the energy required for the high- temperature reduction of the black mass. ii) The current method eliminates the need for unstable and expensive H2O2 or high temperatures. Instead, it employs a more economical reductant, copper, derived from the battery anode, which is subsequently regenerated in the process. iii) The present process facilitates the recovery of transition metal salts that can be utilized in the production of new batteries. This provides an energy-efficient and cost-effective technique for recycling spent Lithium-Ion Batteries. It is thus possible for the present advancement to provide for a process for recovery of critical metals from cathode of the spent Lithium ion batteries containing Lithium and at least one of the transition metals: nickel, manganese and cobalt which comprises of the following steps. a. leaching the compound containing the cathode material in presence of copper to obtain a leached slurry wherein said leaching is carried out by mineral acid such as H2SO4; b. Cementation / removal of copper by addition of iron; c. Removal of ferric iron hydroxide by addition of cathode material and adjusting pH to 2 or above. d. Conversion of iron oxide / hydroxide to metal by carbothermic / hydrogen / hydrocorbons or CO / H2 mixtures

Claims

We Claim:

1. A process for lithium-containing transition metal oxide material based recovery of anyone or more of a transition metals and lithium therefrom comprising:(a) subjecting the lithium-containing transition metal oxide material to a step of acid based reductive leaching initially in the presence of copper as an intermediate reductant prior to addition of any iron reductant;(b) thereafter carrying out cementation / removal of copper (II) by addition of iron;(c) oxidation of dissolved Fe (II) generated in step (b) above for precipitation as iron (III) oxide / hydroxide to thereby provide for solution pregnant with salt / s including Li, Co, Mn and Ni salt / s for recovery therefrom of the desired anyone or more of Li, Co, Mn and Ni.

2. The process for lithium-containing transition metal oxide material based recovery as claimed in claim 1 wherein said lithium-containing transition metal oxide material include lithium-ion batteries, spent batteries, waste battery material from production, off- spec material, and other materials containing lithium and transition metals including Ni, Co, Mn.

3. The process for lithium-containing transition metal oxide material based recovery as claimed in claims 1 or 2 enabling recovery from and recycling of battery cathode oxide compounds from spent batteries with the aid of said both copper and iron as reluctant wherein said step (a) involves subjecting said lithium-containing transition metal oxide material as cathode material compound based first portion of black mass to reductive leaching by involving copper (0) as intermediate reductant; said step (b) involves cementation / removal of copper (II) by selectively involving alternative iron (0) as reductant that gets converted to Fe (II);said step (c) involves oxidation of dissolved Fe (II) attained out of step (b) for precipitation of iron (III) oxide / hydroxide by selectively involving second portion of black mass based cathode material followed by regeneration of iron / iron removal to obtain therefrom said solution pregnant with salt / s including Li, Co, Mn and Ni salt / s recoverable by solvent extraction, precipitation and / or crystallization.

4. The process as claimed in claims 1-3 for said recovery and recycling of battery cathode oxide compounds as critical metals from cathode of spent batteries including from lithium ion batteries containing lithium and at least one of the transition metals: nickel, manganese and cobalt wherein said step (a) involves said subjecting said cathode material compound based first portion of black mass to reductive leaching in presence of copper (0) as said intermediate reductant in excess of stoichiometric amounts and organic / mineral acids including H2SO4 to obtain a leached slurry adapted for solid-liquid separation resulting in clear solution containing Li, Ni, Co, Mn, and / or oxidized Cu(II) in said clear solution; said step (b) involves cementation / removal of copper (II) from said leached slurry based clear solution as Cu (0) by addition of iron (0) as said alternative reductant at pH <5 with iron (0) in turn getting converted to dissolved iron (II) that is followed by solid-liquid separation to precipitate / remove Cu (0) that is recyclable to step (a); said step (c) involves removing said dissolved iron (II) from said leached slurry solution of step (b) by adding said second portion of black mass based cathode material after adjusting pH to >2 for converting iron (II) to ferric iron hydroxide / oxide to facilitate iron removal from solution pregnant with ions including ions of Li, Co, Mn and Ni salts and recoverable by solvent extraction, precipitation and / or crystallization.

5. The process as claimed in claims 1-4 wherein utilizing copper (0) as an intermediate reductant is involved in Stoichiometric to 20% excess of stoichiometric amount prior to involving iron (0) as reductant causes reduced consumption of iron that is reduced to one-third compared to when iron is directly employed as reductant.

6. The process as claimed in claims 1-5 wherein said cathode material compound based black mass is derived from including lithium-containing transition metal oxide material originating from various sources of lithium-ion batteries, including spent batteries, waste battery material from production, off-spec material, and other materials including lithium and transition metal / s M= including Ni, Co, Mn, and representable by chemical formula LiMCh or LioO.MoCh with said transition metal in trivalent state that is dissolvable in acidic solution based on involving copper (0) as intermediate reductant towards bringing said transitional metal to divalent state, as compared to conventional H2O2, SO2 reductants employed for energy intensive high temperature reductions.

7. The process as claimed in claims 1-6 wherein said cementing of Cu (0) by involving iron as alternative reluctant includes iron powder, iron components, iron scrap, sponge Iron (Direct Reduced Iron) or any iron containing alloys / intermetallics.

8. The process as claimed in claims 1-7 wherein said step (b) of cementation / removal of Cu (0) is conducted within a temperature range of room temperature to upto 100°C, within a duration of 5 minutes to 12 hours at pH < 5, preferably < 3, to prevent copper hydrolysis, which cemented copper (0) is separated by solidliquid separation for re-use in step (a).

9. The process as claimed in claims 1-8 wherein said step (c) of iron (II) oxidation for precipitation of iron (III) oxide / hydroxide is carried out by said second portion of black mass based cathode material conducted within a temperature range of room temperature to 100°C, with a duration of 5 minutes to 12 hours and at pH >3 for removal / precipitation of iron (III) oxide / hydroxide from solution.

10. The process as claimed in claims 1-9 wherein said post removal / precipitation of iron (III) oxide / hydroxide from solution in step (c), iron (0) is regenerated from iron(III) hydroxide / oxide by reduction with hydrogen / hydrocarbons / carbohydrates / carbon / coal / coke / charcoal / graphite from anode at temperatures from 400-1200 °C, which iron (0) is reusable for cementation of copper (0) from solution.

11. The process as claimed in claims 1-10 wherein said process is energy intensive and avoids expensive reductants including H2O2, SO2, organic reductants and yet enhances efficiency of reductive leaching of higher oxides present in said black mass with the leach solution obtained after iron removal step being free from impurities such as Cu, Fe and organic reductants whereby more than 98% of Li and transition metals are recoverable from said black mass based battery cathode material.

12. The process as claimed in claims 1-11 wherein said cathode material compound based black mass is derived from sources including lithium-containing transition metal oxide material originating from various sources of lithium-ion batteries, including spent batteries, waste battery material from production, off- spec material, and other materials including lithium and transition metal / s M= including Ni, Co, Mn, derived by including following steps: (i) Discharging the batteries in salt solution followed by shredding; (ii) dismantling by varied physical separation process including sieving, froth flotation, magnetic separation.

13. The process as claimed in claims 1-12 wherein said copper reductant includes copper scrap, PCBs, copper powder, copper sheets from Li-ion battery or copper containing metal / alloys.

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