Electrolytes, methods and equipments for battery elements ion recovery through solid bodies electrodeposition

Abstract

The present invention relates to assemblies, systems, methods, and electrolytes for recovering valuable ions from acidic solutions via electrodeposition, particularly lithium and, to a lesser extent, copper containing lithium traces. Following acidic dissolution of battery components, the resulting metal-containing solution is contacted with electrically conductive porous particles, including, in some embodiments, ion-exchange resins. The ions absorbed by the particles are then electrodeposited onto an electrode using controlled electric pulses. This approach enables the production of high-purity ingots or coatings with homogeneous surface properties, strong adhesion, and improved interfacial electrical performance due to a continuous, defect-free atomic matrix. The invention applies not only to the recovery process but also to the resulting materials, which exhibit unique characteristics in terms of homogeneity, surface quality, chemical composition, and purity, overcoming the limitations of conventional battery recycling methods.

Description

[0001] ELECTROLYTES, METHODS AND EQUIPMENTS FOR BATTERY ELEMENTS ION RECOVERY THROUGH SOLID BODIES ELECTRODEPOSITION

[0002] FIELD OF APPLICATION OF THE INVENTION

[0003] The present disclosure relates to the field of chemical recycling, recovery, and / or revalorization. More in particular, to assembly’s, systems, methods and electrolytes for the recovery and / or revalorization of valuable ions from acidic solutions through selective electroplating techniques, particularly lithium and also the minoritarian elements present in the battery. This process is especially relevant to the recycling of lithium and the other minoritarian components (e.g.: copper, etc.) present in the batteries from discharged battery waste, where the deluded metals in an acidic medium, which is a common stage in waste treatment, is treated through ion-exchange resins which, in several particular embodiments, acts as a scaffold of the dissolution elements, lithium and / or lithium with the minoritarian components present in the batteries.

[0004] The method offers an efficient, scalable, and environmentally friendly solution for extracting ions, such as lithium ions from complex mixtures, typically generated during the recycling of lithium-based batteries, where there is a substantial improvement over the final quality of the recovered metal ingot in terms of tribological, mechanical, physical and electrochemical properties. By employing controlled electrochemical deposition, lithium can be selectively recovered, providing a sustainable approach to recycling critical raw materials from electronic waste streams and contributing to the circular economy in the energy storage industry. This innovation is particularly valuable for industries seeking to reduce raw material dependence and lower the environmental impact associated with battery disposal and manufacturing as well as for company in which they want to revalorize this process to electroplating lithium and copper-lithium base layers to enhance the electrical conductivity of batteries under service-like working conditions.

[0005] BACKGROUND OF THE INVENTION

[0006] The rapid growth of industries dependent on lithium-ion batteries, such as electric vehicles, portable electronics, and renewable energy storage systems, has greatly increased the demand for lithium and other critical raw materials. As these batteries reach the end of their useful life, sustainable recycling methods have become essential to address the environmental and economic challenges associated with battery waste. Conventional recycling processes often involve several recycling steps as well as the dissolution of battery materials in acidic solutions, producing complex mixtures of metals like lithium (Li), copper (Cu), cobalt (Co), nickel (Ni), and manganese (Mn). The recovery of lithium from these mixtures is particularly challenging due to the inefficiencies and limitations of current methods to separate each component.

[0007] A major challenge in these recycling processes is the treatment of residual waste generated during metal recovery. Traditional methods frequently rely on harsh chemicals that produce large quantities of hazardous by-products. These residues, if not treated properly, can pose significant environmental risks, as their disposal is difficult and costly. The residuals from Li recovery operations, particularly those involving mixed metal dissolution, often require further processing, which adds complexity and increases the potential for environmental contamination.

[0008] Another critical issue is the limited quality of the recovered Li metal ingots. Current processes often produce impure ingots, which restrict their potential applications. The presence of contaminants such as Cu, Co, Ni, or Mn compromises the purity of the Li, and as a direct consequence the final properties of the revalorized / . / -component, making it unsuitable for direct use in high-performance applications like battery manufacturing. As a result, the recovered metals often need additional refining steps, which further increases costs and reduces the overall efficiency of the recycling process.

[0009] The inefficiency of conventional methods for obtaining pure / . / -ingots from acidic solutions is a significant concern. When multiple metals are present in solution, such as in the case of battery waste, existing separation techniques struggle to selectively recover Li without also depositing other metals. This results in cross-contamination and low-purity metal ingots, which are not suitable for direct industrial use. This inefficiency not only diminishes the economic viability of the recycling process but also limits the availability of high-quality recycled lithium for reuse in new batteries.

[0010] In conventional electrochemical recovery methods used for extracting metals from spent batteries, the purity of the recovered metals can vary significantly depending on the specific conditions of the process and the metals involved. Typically, the purity of metals like Cu, Ni, or Co can reach between 90 and 99%. However, for Li, which is often present in smaller concentrations and in more complex mixtures, the purity obtained through standard electrochemical recovery methods tends to be lower, often ranging from 70 to 95%.

[0011] Conventional industrial techniques for separating the various elements in spent batteries are both costly and energy-intensive, significantly increasing the overall expense and environmental impact of the recycling process. Methods such as eddy currents are commonly used to separate non-ferrous metals from ferrous components and other materials. While effective, these techniques require substantial energy input and complex equipment to physically sort the diverse materials present in battery waste. The reliance on such mechanical separation processes also increases operational costs, as well as the generation of additional emissions from the machinery involved. Furthermore, the physical separation of elements often does not achieve the level of purity required for efficient downstream recovery, necessitating further processing steps, which adds to both the financial and environmental burden. This complexity in separating battery elements prior to chemical or electrochemical recovery highlights the need for more efficient, integrated approaches to reduce costs and emissions while improving material recovery rates.

[0012] Additionally, the gases emitted during conventional electrochemical deposition processes pose another environmental and operational challenge. The use of high-energy electrochemical methods for metal recovery can lead to the release of harmful gases, such as chlorine or sulfur dioxide, depending on the chemicals involved. These emissions contribute to air pollution and require specialized handling systems to mitigate their impact, further increasing the complexity and cost of the process.

[0013] An additional limitation associated with lithium recovery by electrodeposition methods arises from the inherent chemical nature of lithium itself. Lithium is a highly reactive and easily oxidized element, making its direct electrodeposition from aqueous or acidic solutions extremely challenging. Unlike transition metals such as copper or nickel, which can be reliably electrodeposited under conventional electrochemical conditions, lithium tends to remain in its ionic state in solution, and attempts to reduce it to metallic lithium are hindered by competing reactions, including hydrogen evolution. This not only prevents efficient deposition but also leads to low current efficiencies and significant energy losses. Moreover, the instability of electrodeposited lithium under ambient conditions further complicates its handling and storage, as freshly deposited lithium is prone to rapid oxidation or passivation, reducing its purity and usability. These fundamental challenges in controlling the redox chemistry of lithium during electrodeposition limit the viability of existing electrochemical approaches for producing high-purity lithium ingots from complex acidic leachates.

[0014] There are established methods for treating wastewater and removing heavy metals or Li from water using ion-exchange resins, which have proven effective in capturing and purifying metal ions from aqueous solutions. These resins operate by selectively exchanging ions in the solution with ions attached to the resin, making them a common choice for water treatment applications. However, despite their success in water-based systems, ion-exchange resins have not been widely applied as a method for recovering critical raw materials and in particular metal ions from highly acidic solutions, such as those found in battery recycling processes. The complex nature of these acidic solutions, which contain a mixture of dissolved metals, poses significant challenges for ion-exchange resins, as the resin’s selectivity and capacity can be compromised by the low pH and the presence of competing metal ions. This limitation has prevented their widespread adoption in metal recovery from acid leachates, highlighting the need for alternative technologies specifically designed to operate in these harsh chemical environments.

[0015] As described in EP 24382695.5, said patent application outlines a coating method for providing an object of an electrically conductive material with a metal and / or a metal oxide coating, using a plurality of electrically conductive particles, in some cases including an ion-exchange resin, and at least one electric pulse. However, it has never been attempted to perform a material recovery from an acid solution system based on selective electrodeposition through said conductive particles.

[0016] In light of the exposed issues, there is a clear need for improved methods that address the inefficiencies, environmental concerns, and quality limitations of current Li recovery processes, among others critical row materials.

[0017] SUMMARY OF THE INVENTION

[0018] The present disclosure introduces an advanced and selective recovery process specifically designed to recover high-purity Li from low and medium acidic concentration solutions derived from discharged battery waste, through electrochemical techniques. This method offers significant improvements by minimizing harmful emissions, reducing residual waste, and achieving higher purity in the recovered lithium ingots, making it a more sustainable and efficient solution for the recycling industry.

[0019] The present invention refers to assembly’s, systems, methods and electrolytes for the recovery of valuable ions from acidic solutions through electrodeposition techniques, particularly Li, using a plurality of electrically conductive particles, in some cases including an ion-exchange resin, and at least one electric pulse.

[0020] After an acidic dissolution process, or any possible equivalent under which the metals present in the components located at the interior of the batteries are diluted, a solution conventionally based on an acid as the solvent plus ions is obtained as a product, presenting all the limitations described on the background for its metal recovery. It has now been found a process under which said chemical liquid product is mixed with electrically conductive particles, such as previously treated ion exchange resins, and subsequently the metals absorbed by the ions exchange resin are electrodeposited onto an electrode by the help of electric pulses. This method being able to obtain a recovered high-quality ingot or coating with higher mechanical adhesion due to the affinity between the electroplated layer and the desired substrate depending on the final application. The obtained result, surprisingly presenting homogeneous tribological and better electrical properties at the interface with a continuous chemical bonded atoms along a defects-free matrix.

[0021] In some particular embodiments, where high purity of the recovered ingot or coating is required, an additional step is introduced between the mixing of a liquid chemical product containing the ions to be preferentially recovered with the solid bodies and the electrodeposition recovery. In a particular embodiment where the solid bodies include an ion exchange resin and the metal ions are bonded to its chemical structure, an additional treatment where a chemical product is introduced to obtain a preferential electrodeposition of a certain element in front of the others - being able to produce a selective electroplating process. Adding additional ions compatible with the used ion exchange resin, presenting different affinity for the reactive radicals present on its chemical structure, it is possible to liberate the desired ions from the energy barrier to be overcome during the electrodeposition, due to the bond between them and the radicals. This results on higher mobility under electrophoretic forces of the liberated ions in front of an electrical field, triggering higher deposition rates of said liberated ions.

[0022] The preferential recovery of a certain element in front of the other elements presents on a liquid chemical product mixed with the solid bodies can be also obtained with a particular configuration of electrical pulses. The amplitude, frequency and pause time between pulses are configurable parameters which can be used to have a better control over the element to be preferentially recovered and its structure. Different ions present different electrophoretic mobility , depending on its electric charge and its effective size, according to . = where is the viscosity of the medium, q is the ion electric charge and rthe ion effective size. Increasing the applied voltage will have a higher impact on their q for smaller and highly charged ions, triggering their higher electrodeposition rate. This combined with asymmetric pulse reversed techniques, where the polarity is reversed alternatively with the possibility of playing with the applied voltage during each polarity and the time of a given pulse, offers a good control over the desired final result.

[0023] Direct or alternate current may be used depending on the particular combination of combination of ions to be recovered, substrate, electrolytic solvent, nature of the solid bodies and working conditions used in order to meet the final product specification.

[0024] The importance of the previously particular embodiments of the invention lies in its ability to streamline the recovery of valuable metals, particularly Li, from spent batteries without the need for complex and costly physical separation processes. Unlike conventional methods that rely on energy-intensive techniques composed of different separation steps, such as Foucault currents to separate individual components before recovery, this invention leverages the dissolution of battery elements directly into an acidic solution. This approach eliminates the need for pre-separation of metals, allowing all components to dissolve in only one step into the solution for subsequent electrochemical recovery. By bypassing the limitations of mechanical sorting and achieving efficient metal recovery directly from the mixed ion solution, this process offers a more cost-effective, environmentally friendly, and scalable solution for battery recycling, advancing the state of the art in resource recovery technologies.

[0025] The invention not only applies to the process of material recovery but also to the recovered material, presenting unique properties in terms of homogeneity, chemical composition, purity, surface topography and enhancing the surface integrity in terms of adhesion or cohesion.

[0026] In some cases, the recovered material is in the form of an ingot, being understood as a solid block of any shape. In others the ions are recovered in the form of a coating over a cathode or over a final part for specific purposes, in some cases to be used as a component in the electric and / or electronic industry among other sectors. The recovered material, in some cases is obtained as a metal, in others as a ceramic, such as in the form of metallic oxides.

[0027] In a particular embodiment, the metal obtained presents high purity, in others, is in the form of an alloy with the controllable and desired composition. As explained before, in the particular recovery process comprising electrically conductive solid bodies including different ions to be recovered on its structure, it is possible to control the composition of the obtained alloy.

[0028] In several particular embodiments the recovered ingot or coating is obtained as a metallic oxide. Depending on the configuration of the solid bodies and the electrochemical parameters used, it is possible to play with the galvanic reactions of the recovering ions presents on the deposited surface. The Pourbaix diagrams can be used to estimate the desired component to be electroplated as well as the necessary electrochemical conditions under which a certain element configuration is stable, enabling the possibility of obtaining the recovered materials in different forms, such as an immune metal or a metal oxide.

[0029] The present disclosure also relates to electrically conductive particles for use in said electrodeposition method and a method for preparing the same. In some particular embodiments, the recovery system is used for metal coating, the particles may comprise a metal salt in a specific disposition which has been found to be particularly useful and the method of preparation described provides such specific disposition.

[0030] The scope of the present invention is addressed but not limited to alkaline-earthly (e.g.: Li) and metallic (e.g.: Cu) recovery of components presents on batteries; it applies to any kind of ion recovery by electrodeposition techniques, where said ions coming from a liquid chemical product, has been previously absorbed by electrically conductive solid bodies.

[0031] BRIEF DESCRIPTION OF THE DRAWINGS To complete the description and in order to provide for a better understanding of the disclosure, a set of drawings is provided. Said drawings form an integral part of the description and illustrate embodiments of the disclosure, which should not be interpreted as restricting the scope of the disclosure, but just as examples of how the disclosure can be carried out. The drawings comprise the following figures:

[0032] Figures 1 A to 1 E: Show flux diagram representations of a typical method for ion dilution for its recovery coming from a battery recycling process (1 10) and of the different steps to be performed by the recovery ion electrodeposition methods through free solid bodies (120), (126), (135), (144), and (154) covered by the present invention.

[0033] Figure 2: Shows a graphical representation of the process under which the diluted metal ions comprised on a liquid chemical product are absorbed by a set of electrically conductive free solid bodies before its electrodeposition.

[0034] Figure 3: Shows a graphical representation of an additional treatment introduced between the mixing of a liquid chemical product containing ions to be recovered with the solid bodies and its recovery, where a chemical product is used for controlling the ions to be preferentially recovered.

[0035] Figure 4: Shows a graphical representation of the electrodeposition recovery method through electrically conductive free solid bodies, according to the present invention.

[0036] Figures 5A and 5B: Show bar plots representing the atomic % of the alloying and the deposited elements detected by Energy-Dispersive Spectroscopy (EDS) of a brass plate over which different ion recovery methods have been applied.

[0037] Figures 6A and 6B: Show images taken by Secondary electrons (SE) in Scanning Electron Microscopy (SEM) of a brass plate before (Figure 6A) and after the electrochemical ion recovery (Figure 6B).

[0038] Figure 7: Shows a graphical representation of the electrodeposition of an ion, such as lithium is carried out into a liquid metallic solution, such as a mercury-based amalgam (704).

[0039] DETAILED DESCRIPTION

[0040] The present invention includes a material recovery process of the ions present on a liquid chemical dissolution by electrodeposition methods based on electrically conductive particles (also referred to herein as electrically conductive solid bodies) containing said ions.

[0041] The scope of the present invention is addressed, but not limited, to metallic and alkaline earth recovery of components present on batteries; it applies to any kind of ion recovery by electrodeposition techniques, where said ions coming from a liquid chemical product, has been previously absorbed by electrically conductive solid bodies.

[0042] The present invention also addresses, but is not limited, to Li, Cu, Co, Ni, and Mn ion recovered objects. In some cases, in the form of a solid ingot, in others as a coating. Sometimes the object recovered is in a metallic form, in others is a ceramic, for example, in the form of metallic oxide with different oxidation states.

[0043] As described in Fig. 1 , the present invention refers to a recovery method of the ions presents to a liquid chemical product (1 19 or 121 ). Said liquid (119), in several particular embodiments, comes from the initial stage of a standard battery-recycling process. Fig. 1 describes an example of a standard battery-recycling process (1 10), where as a result, a liquid chemical product containing the ions to be recovered (1 19) is achieved. Initially, the battery is discharged

[0044] (11 1 ), a process used to eliminate the electrical activity of the electrolyte present inside the battery. After the discharge of the battery the components inside the battery are dissembled

[0045] (112) and divided (1 13) into polymeric (114) and non-polymeric materials (1 15). Said non polymeric materials are deluded by chemical reactions with an acidic solution (116). After some reaction time, a process to separate or filter (1 17) the solid waste (1 18) from the liquid chemical product containing the ions to be recovered (119) is performed.

[0046] Once obtained a chemical dissolution containing the ions to be recovered (121 ) from any possible battery-recycling circuit (1 10), the recovery process (120) is applied, as described in Fig 1. The first step is to mix or combine (122) the chemical dissolution containing the ions to be recovered (121 ) with a previously configured electrically conductive solid bodies. After being mixed, means for providing agitation, so the dissolved ions are absorbed by the solid bodies, are applied (123). Finally, the dissolved ions are recovered by electrodeposition (125) by applying a voltage and / or a current to an object electrically connected to a first pole of at least one electric source, the object being at least partially submerged in a medium comprising electrically conductive particles containing the ions to be recovered such that at least part of the surface of the object is in contact with the medium, and a container containing the medium being electrically connected to a second pole of the at least one electric source. Optionally, a preferential recovery treatment (124) can be used for controlling the ions to be preferentially recovered to the combined solid bodies containing said dissolved ions, wherein the treatment includes an exchange between introduced ions and the ions to be preferentially recovered with active groups of the ion exchange resin, the introduced ions presenting a higher affinity to the reactive groups of the ion exchange resin than the ions to be preferentially recovered and lower affinity than the ions with less recovery preference, so that a higher electrodeposition rate of the ions to be preferentially recovered is obtained upon applying an electric pulse. Fig. 2 represents the of the process under which the diluted metal ions comprised on a liquid chemical product are absorbed by a set of electrically conductive free solid bodies before its electrodeposition. A liquid chemical product containing the ions to be recovered (210), according to some particular embodiments of the present invention, includes a solvent (211 ) and ions (212). In several particular embodiments, the solvent (211 ) is an acid, in others a base. In several particular embodiments, the ions (212) to be recovered are cations, in other anions.

[0047] In Fig. 2 is also illustrated the required configuration of the electrically conductive free solid bodies (220) to be mixed with the liquid chemical product containing the ions to be recovered (210). The solid bodies (222) are configured in a way that present affinity to retain said liquid, while capturing the ions (212).

[0048] For this reason, in a particular embodiment of the invention, the solid bodies (222) present a sufficiently low percentage of moisture to ensure the desired effect. Preferably the solid bodies present a humidity between 10 and 90 wt. % with respect to their total weight, particularly between 15 and 50 wt.%, preferably between 20 and 35 wt.%.

[0049] In a particular realization of the invention, a feature to be considered and configured for ensuring the capacity of the solid bodies (222) to retain said liquid the ions (212), so that the ions (212) are captured, is the chemical composition of said solid bodies (221 ).

[0050] The electrically conductive solid bodies may preferably comprise a chelating resin and / or an ion exchange resin and they may also comprise a liquid electrolyte. The liquid electrolyte may preferably includes an acid, in particular an acid solution, and more in particular an aqueous acid solution. The acid contained by the solid bodies preferably includes an acid selected from sulfuric acid, sulfonic acid, nitric acid, phosphoric and / or acetic acid.

[0051] In some cases, the electrically conductive solid bodies include ion exchange resin in its structure.

[0052] In a particular embodiment of the invention, the ion exchange resin include a strong acid cation (SAC) resin, such as styrene-divinylbenzene with a macroporous or gel structure with a sulfonic acid (-SO3H) acting as a functional group, Poly(perfluorosulfonic acid) resins, Perfluoro vinyl ether with sulfonic acid group polymer, Polytetrafluoroethylene (PTFE) with sulfonic acid side chains, Phenol-formaldehyde sulfonic acid resin, Phenolic polymer with sulfonic acid groups, Poly(phenol-sulfonic acid) resin, Poly(acrylic acid-co-divinylbenzene) sulfonated resin, Sulfonated polyacrylic acid copolymer, or Crosslinked polyacrylic resin with sulfonic acid functional groups.

[0053] In a particular embodiment of the invention, the ion exchange resin include weak acid cation resin (WAC), such as Poly(acrylic acid) weak acid cation resin, Crosslinked poly(acrylic acid) resin, Poly(acrylic acid-co-divinylbenzene) resin, Poly(methacrylic acid) resin, Crosslinked poly(methacrylic acid) with divinylbenzene, Methacrylic acid-divinylbenzene copolymer resin, Crosslinked iminodiacetic acid functionalized resin, Chelating resin with iminodiacetic acid groups, or poly(styrene-divinylbenzene) copolymer with iminodiacetic acid.

[0054] In a particular embodiment of the invention, the composition of said solid bodies (221 ) include chelating resin, such as Poly(styrene-divinylbenzene) resin with iminodiacetic acid functional groups, Crosslinked iminodiacetic acid chelating resin, Iminodiacetic acid-functionalized copolymer resin, Crosslinked aminophosphonic acid chelating resin, Poly(styrene-divinylben- zene) resin functionalized with aminophosphonic acid, Aminophosphonic acid-functionalized copolymer resin, Crosslinked polystyrene-divinylbenzene resin with thiourea groups, Thiourea- functionalized styrene-divinylbenzene copolymer, or Poly(styrene-divinylbenzene) resin with thiourea chelating groups.

[0055] A successful mixing process (230) is obtained by adding the solid bodies (220) to the liquid chemical product containing the ions to be recovered (210). In a particular embodiment, the mixture is agitated to ensure homogenous mixing. The combined solid bodies (231 ) after the mixing process represented on Fig. 2, have included the ion (212) on its structure (232). In several embodiments, the inclusion of the ions (212) is by absorption mechanisms, due to capillary forces, in others is because of a chemical bond and / or an electric attraction between chemical components of the solid bodies, like the sulfonic functional groups in the case of a sulfonated styrene-divinylbenzene copolymer.

[0056] Depending on the inclusion mechanism of the ions by the solid bodies (232), certain configurations are required for a successful inclusion. The ions (212) can be anions or cations, and depending on their nature, compatibility with solid bodies used is required. In the case of using an ion exchange resin or a chelating resin, the ions must be compatible with the used resin type.

[0057] Furthermore, the inclusion mechanism of the ions by the solid bodies (232) is guided through the solvent (21 1 ), certain configurations are required for a successful inclusion. The solvent (21 1 ), in particular embodiments, can be an acid or a base, and depending on its nature, compatibility with solid bodies used is required. In the particular case of using an ion exchange resin, solvent (21 1 ) must be compatible with the used resin type (221 ).

[0058] In several embodiments, acids are included in the used solvent (21 1 ), such as sulfuric acid, sulfonic acids or nitric acid, including Cu, Co, Mn, Al, Ni or Li ions of the ion spices to be recovered (212). And the used solid bodies (222) are particles including sulfonated styrene- divinylbenzene copolymer, with sulfonic functional groups (221 ), capable of interacting with the metallic cations (232). In particular embodiments of the invention the used solvent presents the properties for keeping the ions to be recovered in its ionic state in the solution. In some cases, such as where Li ions are the ion spices to be recovered (212), the used solvent (211 ), includes a strong mineral acid, like Hydrochloric Acid (HCI), Nitric Acid (HNO3), or Sulfuric Acid (H2SO4). In others, the used solvent (211 ), includes Perchloric Acid (HCI04). In others, the used solvent (211 ), includes an organic acid he used solvent (211 ), includes Organic Acids, such as Acetic Acid (CH3COOH) or Oxalic Acid (C2H2O4),

[0059] In a particular embodiment of the invention, floating agents can be used for better control of the precipitation of certain ions to be recovered from the solution, such as Terpignol 0.5 - 1 %.

[0060] In several particular embodiments a deep eutectic solvent (DES) it is used as the liquid solvent containing the ions to be recovered which is introduced to the electrically conductive free solid bodies (21 1 ). These solvents are helpful to prevent any possible undesired oxide creating during any step of the recovery process. The solvents presenting said properties include Choline chloride + Urea, Choline chloride + Glycerol, Choline chloride + Ethylene glycol, Choline chloride + Lactic acid, Choline chloride + Citric acid, Menthol + Decanoic acid, Betaine + Malonic acid, Choline chloride + Oxalic acid, Resorcinol + Urea, Choline chloride + Sucrose, among others.

[0061] In one embodiment of the invention, the process of selective ion recovery comprises a sequence of treatments designed to maximize the retention and recovery of lithium while minimizing the co-deposition of undesired metal ions.

[0062] In some embodiments the method comprises dissolving the ions to be recovered in an acid solution and introducing the ions to be recovered by mixing the solid bodies with the acid solution comprising the ions to be recovered, preferably the acid concentration of the acid solution used to dissolve the ions to be recovered and included on the electrically conductive free solid bodies is between 10 and 60 wt. %, particularly between 15 - 50 wt. %, more in particular between 15 - 30 wt. %.

[0063] In some embodiments, the ions to be recovered are maintained in an anhydrous medium by replacing aqueous residues, e.g., derived from such acidic treatment for dissolving the ions to be recovered, with a neutral organic solvent selected from ethylene glycol, propylene glycol, butylene glycol, or dimethyl sulfoxide (DMSO). Replacing may be performed by, e.g., washing the solid bodies containing the ions to be recovered by said neutral organic solvent, in anhydrous conditions, and maintaining the solid bodies comprising the ions to be recovered in such anhydrous medium.

[0064] A representative method includes the preparation of an acidic solution containing dissolved metallic ions obtained from battery waste, which is subsequently put in contact with an ion exchange resin. The resin retains the ions of interest, after which it is immersed in an organic medium such as ethylene glycol. At this stage, the residual aqueous acidic content is displaced and replaced with a neutral, non-acidic solution to avoid premature release of the captured metallic ions. Following this washing step, the ion-loaded resin is subjected to an electrochemical treatment in absence of water, typically employing an organic acid such as methanesulfonic acid (MSA) or acetic acid to promote an equilibrium reaction enabling efficient desorption and electrodeposition of the ions. The deposition occurs within an organic solvent medium, which ensures anhydrous conditions and leads to high-purity metallic coatings or ingots with superior mechanical and electrochemical properties. Suitable organic solvents include, but are not limited to, ethylene glycol, propylene glycol, butylene glycol, and dimethyl sulfoxide (DMSO).

[0065] In one particular embodiment, the method for selective ion recovery comprises a sequence of treatments aimed at maximizing lithium retention while minimizing the co-deposition of other metallic ions. The method begins with the preparation of an acidic solution containing dissolved metals from battery waste, which is contacted with an ion-exchange resin. The resin captures the ions of interest and is subsequently transferred into an organic medium, such as ethylene glycol, to displace the residual aqueous acidic content. This replacement step ensures that a neutral, non-aqueous environment surrounds the resin, preventing premature ion release. Next, the ion-loaded resin is subjected to electrochemical treatment under anhydrous conditions, often with the aid of an organic acid such as methanesulfonic acid (MSA) or acetic acid. These acids facilitate equilibrium reactions that enable efficient ion desorption and subsequent electrodeposition. The deposition step is carried out within the organic solvent medium, resulting in high-purity metallic coatings or ingots with enhanced mechanical and electrochemical performance. Suitable solvents include ethylene glycol, propylene glycol, butylene glycol, dimethyl sulfoxide (DMSO), or mixtures thereof.

[0066] In a similar embodiment, the process employs porous organic resins specifically configured for lithium recovery. These resins contain organic groups that present selective affinity for the lithium ions such as, but not limited to, crown ethers, preferably lithium selective crown ethers. The complex is such that in an acidic solution containing multiple dissolved metallic ions, lithium species are preferentially captured in an ionic resin due to charge affinity differences, while other metallic ions remain unbound. An acid solution containing metal ions is put in contact with the resin (128). Resin is then separated (129) from the acidic solution (130) and metal (lithium)-coordinated ions (131 ) are recovered from the resin via controlled desorption using a suitable solvent (132). Such solvents include, but are not limited to, inorganic acids and organic acids, preferably HCI. The recovery process (120) is applied to the obtained metal (Li) solution (134), and metal (Li) is recovered. In some embodiments, the process employs porous organic ion-exchange resins that are specifically functionalized to enhance selectivity toward lithium ions. These resins may be chemically modified with organic groups that exhibit strong affinity for lithium, such as but not limited to crown ethers, cryptands, or calixarenes, with lithium-selective crown ethers (e.g., 12-crown- 4 or its derivatives) being particularly preferred for some specific embodiments. In certain configurations, the resin is further combined with complexing agents capable of stabilizing the ions within an acidic multi-metallic solutions, preventing them from forming oxides. For instance, in the presence of competing ions such as Cu2+, Ni2+, Co2+, and Mn2+, complexing ligands like ethylenediaminetetraacetic acid (EDTA), oxalates, or phosphonate-based agents can be introduced to preferentially retain or mask these competing species, thereby enhancing the relative capture of Li+ions within the resin matrix.

[0067] During operation of some embodiments (126) described on Fig. 1 B, an acidic leachate containing dissolved metal ions (127), such as HNO3, H2SO4or HCI solutions enriched with Li+, Ni2+, and Co2+from spent battery cathodes, is brought into contact with the functionalized resin (128). Lithium ions are selectively coordinated and immobilized within the resin structure due to the tailored ion-ligand interactions, while most other metallic ions remain in solution (130). The lithium-loaded resin (129) is subsequently separated, and controlled desorption (131 ) of lithium is achieved by treatment with a suitable solvent (132). Examples of desorption solvents include inorganic acids such as HCI or HNO3, as well as organic acids like citric acid or oxalic acid, depending on the downstream purification strategy. The resulting lithium-enriched solution (134) can then undergo further recovery steps (120) and thereby producing high-purity lithium compounds suitable for direct reuse in battery manufacturing.

[0068] In a particular embodiment, the process (135) makes use of a complexing agent that bonds exclusively with lithium, such complexing agents include, but are not limited, to 12C4 and 15C5 crown ethers and their derivatives. The complex is such that when an acid metal solution is put in contact with the solid bodies (138), non-complexed metal ions are sorbed by the resin, but complexed Li ions are not. The resin is then separated from the solution (139). The lithium- coordinated ions (141 ) are separated from the complexing agent (142) and then recovered following the recovery process (120).

[0069] In another embodiment, the process (144) employs basic resins specifically configured for lithium recovery. In this process lithium forms a compound with a complexing agent in the metal rich acidic solution (146). Such complexing agents include, but are not limited, to 12C4 and 15C5 crown ethers and their derivatives. The complex is such that when it is mixed with an acidic solution containing multiple dissolved metallic ions, the lithium species preferentially form a complex and Li-complexes are preferentially sorbed by the resin due to charge affinity differences, while other metallic ions remain unbound (147). The resin is then separated (148) from the acidic solution and lithium-coordination compounds (150) are recovered from the resin via controlled desorption using a suitable solvent (151 ). The lithium-coordinated ions are then separated from the complexing agent (152) and recovered following the recovery process (120).

[0070] The recovery process can be performed after processes (124), (135) and (144) can follow other embodiments of the inventions and combinations of, such as, but not limited to, using DES or anhydrous protic solvent. These approaches allow highly selective lithium capture and recovery.

[0071] In a further embodiment, the ion exchange system is based on an advanced titanium-oxide- derived sorbent material designed for lithium extraction. These titanium-based exchangers take advantage of the high affinity of titanium oxide functional groups for lithium ions, thereby enabling preferential adsorption of lithium even in solutions containing significant concentrations of other transition metals. Through sequential cycling steps — including adsorption, washing, and electrochemical desorption — the lithium yield can be progressively enhanced, with recovery rates being improved at the expense of additional processing time. This sacrificial time approach increases the overall process efficiency while maintaining high selectivity for lithium.

[0072] These embodiments highlight the versatility of the disclosed invention in that specific combinations of inorganic sorbents, organic solvents, and ion-exchange resins can achieve highly selective lithium recovery under controlled aqueous and non-aqueous electrochemical conditions.

[0073] In a particular embodiment, as shown on Fig 1 -C, the process (135) utilizes a complexing agent designed to bond selectively with lithium ions. Suitable complexing agents include, but are not limited to, lithium-selective crown ethers such as 12-crown-4 (12C4) and 15-crown-5 (15C5), along with their functional derivatives. When an acidic, metal-rich leachate, such as HCI, HNO3, or H2SO4solutions containing Li+, Ni2+, Co2+, and Mn2+, is introduced to the conductive solid bodies (138) containing such agents, the lithium ions form stable complexes. In this configuration, competing transition-metal cations are preferentially retained by the resin, whereas the complexed Li+species remain unbound in solution due to steric and charge exclusion effects. After resin separation (139), the lithium-coordinated ions (141 ) can be isolated from the complexing agent (142), for example via solvent-assisted dissociation using ethanol, methanol, or mild inorganic acids. The released lithium solution is subsequently subjected to the recovery process (120), yielding pure lithium or pure lithium salts such as lithium carbonate (Li2CO3) or lithium hydroxide (LiOH). In another embodiment shown on Figure 1 -D, the process (144) employs strongly basic ionexchange resins specifically functionalized for lithium recovery. Here, lithium forms coordination complexes in the acidic leachate (146) with selective agents, such as 12C4, 15C5, or polyethylene glycol (PEG)-modified macrocycles. These lithium complexes exhibit preferential affinity toward the resin’s functional groups, such as quaternary ammonium or imidazolium moieties, enabling their selective sorption from solutions containing competing divalent and trivalent metal ions (147). Following resin separation (148), lithium complexes (150) can be desorbed under controlled conditions using solvents (151 ), including hydrochloric acid, citric acid, or ionic liquids tailored for complex destabilization. The lithium-coordinated ions, in some embodiments, are then separated from the complexing agents (152), after which the recovery process (120) is applied, ensuring high-purity lithium salts suitable for downstream battery remanufacturing.

[0074] The recovery process following steps (126), (135), and (144) may also be combined with alternative solvent systems, such as deep eutectic solvents (DES) or anhydrous protic solvents (e.g., methanol or ethanol), to enhance selectivity, reduce solvent toxicity, and improve process scalability. Such hybrid strategies allow integration of multiple embodiments into a modular recovery platform.

[0075] In a further embodiment, the ion-exchange system is based on advanced titanium-oxide-de- rived sorbent materials engineered for lithium extraction. Titanium-based exchangers, such as lithium-ion sieves derived from spinel-type Li4Ti50i2or layered H2TiO3, exhibit high affinity for lithium ions due to the favorable interaction of Ti-0 surface groups with Li+. These sorbents demonstrate strong lithium selectivity even in the presence of competing ions like Na+, Mg2+, and Ca2+, which are common in recycling leachates and brine sources. Through sequential adsorption-washing-desorption cycles, lithium recovery yields can be progressively enhanced. Desorption may be achieved via mild acidic solutions (e.g., HCI or HNO3) or electrochemical regeneration steps using the described alternative solvent systems, enabling efficient lithium release while maintaining sorbent stability. Although these multi-step cycles increase processing time, they provide improved overall recovery rates and high product purity.

[0076] These embodiments collectively demonstrate the versatility of the invention, whereby combinations of inorganic sorbents, organic complexing agents, deep eutectic solvents, and functionalized ion-exchange resins can be tailored to achieve highly selective lithium capture and recovery under both aqueous and non-aqueous electrochemical conditions.

[0077] The present invention also discloses the synergy between the acid dissolution composition and the further method for the selective recovery process. Due to the different solubility of certain elements on certain acids, it is also possible to configure the used acidic solution in a way that enables better control on the dissolution of the desired element to be recovered over the undesired elements. The temperature under which the dissolution is performed also has a different impact on the dissolution rate of different acid-element combination, enabling a better control on the dissolution of the desired element to recovered over the undesired elements.

[0078] In Example 3, sulfuric acid has been used, while nitric acid has been used in Example 2. Both examples have been performed under the same conditions, only changing the dissolution acid, and its concentration, under which the ion dissolution has been carried out. In Fig 5. it is observable that using sulfuric acid promotes a better dissolution of some elements in front of others, as well as decreasing the used electrical parameters like in Example 1 . It also enables better control over the purity of Li on the recovered material, However, using nitric acid allows a better dissolution of all other materials present inside the battery, achieving a complete dissolution with lower acid concentrations, eliminating any further step required for other acids, such as the sulfuric acid. Any combination of different acids is under the scope of protection of the present invention.

[0079] In a particular embodiment, in which at least two different qualities in terms if Li purity over copper is obtained, a concatenation of at least two steps is performed. A first step using sulfuric acid for a preferential Li dissolution, achieving higher Li purity of the final recovered material. A second step performed to the separated of the undissolved elements using nitric acid, allowing a complete dissolution of all components and obtaining a lower Li purity of the final recovered material. As a result, a complete recovery process is applied to all components of for example a battery, obtaining different levels of purity depending on the final application.

[0080] Any other possible configuration between solvents, ions and solid bodies is on the scope of the present invention.

[0081] In several particular embodiments, a preferential recovery treatment is applied after the mixing step. As described in Fig. 3, the treatment leads to include to the solid particles an additional ion (310), so that the preferential ion to be recovered is liberated by the solid bodies for the inclusion of said additional ion (320) because a difference on its affinity to be retained by the solid bodies (330).

[0082] In some embodiments a method as described herein may include a treatment for controlling the ions to be preferentially recovered to the combined solid bodies containing said ions. For instance, the treatment may be performed to the electrically solid bodies containing the ions to be recovered after having been captured. The treatment may be particularly interesting wherein a mixture of different ions have been captured and there are ions that are to be preferentially recovered and there are ions with less recovery preference. In such case a yet third ion different from the preferentially and less preferentially recovered, may be used and introduced in such a treatment to perform a selective ion exchange For instance, the treatment includes an exchange between introduced ions and the ions to be preferentially recovered with active groups (or reactive groups) of the solid bodies The introduced ions present a higher affinity to the reactive groups of the solid bodies than the ions to be preferentially recovered and a lower affinity than the ions with less recovery preference, so that a higher electrodeposition rate of the ions to be preferentially recovered is obtained upon applying an electric pulse.

[0083] In other words, the method may comprise a treatment for controlling the ions to be recovered, wherein the combined solid bodies comprise active groups (or reactive groups) and comprise at least a first and a second ion, wherein the first and second ions are different and wherein the first ion is to be preferentially recovered and the second type has less recovery preference. The treatment is applied to the solid bodies, and the treatment comprises introducing a third ion, by combining the solid bodies with a solution comprising said third ion to be introduced, thereby performing an exchange between introduced ions and the ions to be preferentially recovered with the active groups of the solid bodies, is performed. The introduced ions presenting a higher affinity to the reactive groups (or active groups) of the solid bodies than the ions to be preferentially recovered and a lower affinity than the ions with less recovery preference. Thereby, a higher electrodeposition rate of the ions to be preferentially recovered is obtained upon applying an electric pulse.

[0084] In some embodiments, the ion to be preferentially recovered is lithium and the introduced ions for lithium preferential recovery over copper are calcium ions.

[0085] In a particular embodiment, which is part of the scope of the invention, said treatment for controlling the ions to be preferentially recovered to the combined solid bodies containing said ions (310), wherein the treatment includes an exchange between introduced ions and the ions to be preferentially recovered with active groups of the solid bodies (320), the introduced ions presenting a higher affinity to the reactive groups of the solid bodies than the ions to be preferentially recovered and lower affinity than the ions with less recovery preference (330), so that a higher electrodeposition rate of the ions to be preferentially recovered is obtained upon applying an electric pulse.

[0086] In a particular embodiment, the structure of the mixed solid bodies (31 1 ) is an ion exchange resin, in particular, a sulfonated styrene-divinylbenzene copolymer, retaining Li as the preferential ion to be recovered (312) with other ions (314), such as Cu, Al, Co, Ni, Mn, calcium (Ca) ion among others, are included as the additional ion to be exchanged (313). After its combination, the additional ion to be exchanged (322), such as Ca, K, or Na, has been exchanged with the preferential ion to be recovered (323), where the ion exchange resin (321 ) retains at least a portion of the introduced ions (322), such as Ca+2, among other ions (324), such as cupper ions (preferentially Cu+2), liberating at least a portion of the ions to be preferentially recovered (323), such as Li+. Said selective effect (330) is enabled as the affinity of the resin to retain the ions to be preferentially recovered (333) is lower than the affinity to retain the introduced ions (332), them presenting bough lower affinity than the rest of the ions (331 ).

[0087] In several particular embodiments, a deep eutectic solvent (DES) is used as the liquid solvent containing the ions to be recovered which is introduced to the electrically conductive free solid bodies. In others, after an acidic liquid solvent is combined with the solid bodies, once the ions are introduced to the solid bodies structure, said acid solvent is evacuated, such as by evaporation, and a DES is introduced for guiding the electrodeposition ion recovery. In a particular embodiment, for promoting a selective preferential ion recovery method, DES including particular selective ions (322) are selected, such as Calcium chloride + Urea, Calcium chloride + Glycerol, Potassium carbonate + Glycerol, Potassium chloride + Urea, Sodium chloride + Urea, Sodium acetate + Glycerol, Sodium chloride + Lactic acid, or any other containing ions with the mentioned properties or requirements for a selective recovery system.

[0088] A method for ion recovery as described herein comprises: configuring a set of electrically conductive solid bodies to retain a liquid chemical product containing the ions, preferably metal ions, to be recovered; combining said solid bodies with a liquid chemical product containing the ions to be recovered, so that at least part of said ions are captured by the solid bodies; applying a voltage and / or a current density to an object electrically connected to a first pole of at least one electric source, the object being at least partially submerged in a medium comprising the set of electrically conductive bodies, also referred to herein as electrically conductive particles, containing the ions to be recovered such that at least part of the surface of the object is in contact with the medium, and a container containing the medium being electrically connected to a second pole of the at least one electric source; wherein applying a voltage and / or a current density to the object, comprises applying at least one electric pulse, whereby the object is provided with at least some recovered ion, preferably with a metal ion and / or metal ion oxide.

[0089] The electrochemical method under which the desired ions are recovered is illustrated on, e.g, Fig. 4. Describing a method for ion recovery, according to the present invention, comprising:

[0090] • Configuring a set of electrically conductive solid bodies to retain a liquid chemical product containing the ions to be recovered;

[0091] • combining said solid bodies with a liquid chemical product containing the ions to be recovered, so that at least part of said ions are captured by the solid bodies (415);

[0092] • applying a voltage (41 1 ) and / or a current density (412) to an object electrically connected to a first pole (413) of at least one electric source (41 1 ), the object (416 and 423) being at least partially submerged in a medium comprising electrically conductive particles containing the ions to be recovered (415 and 421 ) such that at least part of the surface of the object is in contact with the medium, and a container containing the medium (414) being electrically connected to a second pole (416) of the at least one electric source (411 );

[0093] • wherein applying a voltage and / or a current density to the object, comprises applying at least one electric pulse, whereby the object (423) is provided with some ion and / or ion oxides (422).

[0094] Configuring a set of electrically conductive solid bodies to retain a liquid chemical product containing the ions to be recovered, may comprise simply providing a set of electrically conductive solid bodies which are already adequate for retaining said liquid chemical product containing the ions to be recovered, or may comprise the adequation of a set of electrically conductive solid bodies so that they are suitable for retaining said liquid chemical product containing the ions to be recovered. For instance, adequation may comprise contacting solid bodies with a liquid electrolyte making them electrically conductive and, e.g., particularly suited for the ions to be recovered in a specific process. The liquid electrolyte may include an acid, in particular an acid solution, and more in particular an aqueous acid solution.

[0095] By combining the set of electrically conductive solid bodies with the liquid chemical product containing the ions to be recovered, at least part of said ions are captured by the solid bodies. Captured is understood as the ions to be recovered are removed from the liquid chemical product and brought onto or into the solid bodies, e.g., they may be adsorbed, absorbed, chelated and / or ion exchanged, onto or into the solid bodies.

[0096] In some embodiments the ions to be recovered are metal ions (also referred to herein as metallic ions) and the object is provided with a metal ion and / or metal ion oxide, obtained from said metal ions, thereby recovering the metal ions onto the object.

[0097] The ions to be recovered may be preferably selected from lithium, iron and copper, preferably is lithium.

[0098] As the ions may be recovered in their neutral (metallic) form, the recovered ions may also be referred to as recovered metallic element, for instance wherein the recovered metal ion, is lithium the recovered metallic element is metallic lithium. The ions may also be recovered as part of an oxide, e.g., in the form of metal oxides.

[0099] Applying a voltage and / or a current density to the object and to the medium comprising the solid bodies, results in the object being provided with ion and / or ion oxides. Prior to or simultaneously to applying the voltage, desorption of the ions to be recovered from the solid bodies may be achieved as described in further detail below. Desorption will make the ions to be recovered available for electrochemical deposition onto the object.

[0100] In a particular embodiment of the invention, the electrodeposition process is performed while applying a relative movement between the solid bodies and the object where the ions are deposited. In some particular embodiments, the relative movement is performed by applying motion to the object immersed in the medium containing the solid bodies. Other means for supplying the solid bodies to the surface of said object, such as by projection or shooting means, are also in the scope of the present invention.

[0101] The electrodeposition recovery method, according to the present invention, involves applying an electric pulse, either under applied voltage or current density control, to electrodeposit or coat an object with the metallic ions to be recovered. The pulses or pulse application time can range from 1 to 120 minutes, and in specific cases, from 5 to 60 minutes. The method can work under either voltage and / or current density control mode. Voltage for these electric pulses may vary from 0 to 150V, with pulses achieving up to 130V or higher. The advantage of using pulses, especially at high voltages, is that they prevent excessive heating caused by continuous currents, which can degrade the electrolyte and electrically conductive particles through the Joule’s effect. Pulsing helps manage temperatures and extends the life of the conductive particles. Furthermore, from the coating viewpoint, these high applied voltage pulses lead to generate a homogeneous plating layer without high density of defects observed by field emission scanning electron microscopy (FE-SEM), mainly cracks, at the superficial level.

[0102] When controlled by current density, pulses range from -5 to 5 A / dm2, with optimal current densities up to 2 A / dm2helping to minimize dehydration and structural defects in the coating, such as minimizing dendritic growth. These current densities also contribute to improved shine and coating quality. The pulse process generally uses between 1 to 104 electric pulses, with the pulses applied at frequencies between 0.05 to 30.0 Hz. Lower frequencies, especially around 0.8 Hz, are ideal for metal oxide coatings, while higher frequencies are suited for metal coatings. These frequencies reduce heating and defects, leading to more durable and homogenous coatings. It has been unexpectedly discovered that high temperatures are not required for the described method. Submerging can be done at temperatures ranging from 10 to 90°C, with optimal ranges being 12 to 75°C, 15 to 60°C, and preferably 20 to 50°C. Furthermore, from the coating viewpoint, the applied current density generates a homogeneous platting layer without high density of defects observed by field emission scanning electron microscopy (FE-SEM), mainly cracks, at the superficial level.

[0103] The low-frequency pulses with a duty cycle ranging between 10 to 40%, preferentially around 20%, can be configured in various forms, including square wave or symmetric wave pulses, with unipolar square waves being used for DC currents in anodizing processes. Symmetric wave pulses are employed with AC currents, where pulse timings can be adjusted for optimal performance in either anodizing or electroplating processes. Additionally, the method may involve one or more coating cycles, reusing the electrically conductive medium, though in some cases, only one or a few cycles (1 -10) may be preferred for effective coating. The method optimizes energy usage and extends the lifespan of the materials involved, while ensuring high-quality, defect-free coatings.

[0104] In several particular embodiments, the use of asymmetric voltages, where the voltage amplitude varies depending on the applied polarity, can help control the composition of the electroplated layer by selectively influencing different reactions during the deposition process. This allows for more precise tuning of the coating's properties in terms of adhesion as well as leading to enhance the electrical conductivity at the interface.

[0105] The invention applies not only to the material recovery process but also to the recovered object, which contains at least a portion of the targeted ions, also referred to as the ions to be recovered, preferably a target metal ion.

[0106] The recovered object demonstrates unique properties such as high homogeneity, excellent surface topography, adhesion and significant purity, making it versatile for various applications. In some cases, the object is obtained as an ingot-like solid shape, while in others, ions are recovered as a coating on a surface, such as a cathode or a finished part. The recovered material can be a metallic alloy (also referred to as metal alloy) or a metal oxide (also referred to as metallic oxide), depending on the recovery process and desired outcome.

[0107] Accordingly, an object obtainable by a method as described herein contains at least a portion of the ions to be recovered. The object subjected to a process as described herein, at the end of the recovery process may be referred to as the recovered object. The object may be obtained in the form of an ingot-like solid shape or the form of a coating. The object subjected to the recovery process may be typically provided with a coating comprising the at least portion of the ions to be recovered, and may even result in a solid piece made of recovered ions. The recovered object can achieve a purity level ranging from 90 to 100 wt. %, often between 95 and 100 wt. % by weight, relative to the ions that are preferentially recovered. As a mode of example, a recovered object with a purity in the ranges defined, will have 90 to 100% of the weight added to the object through the recovery process which corresponds to the weight of the ions that are preferentially recovered. For instance, when recovering lithium from mixtures of lithium and copper, the recovered object will have a purity of 90 to 100 wt.% of lithium with respect to the total weight added to the object. Wherein the recovered metallic object comprises metallic lithium, the metallic lithium recovered may be obtained with a purity greater than 99 wt.% relative to lithium. This process allows for the production of either high-purity metals, alloys or metal oxides with customizable compositions. In certain instances, when electrically conductive solid bodies containing various ions are used, the composition of the recovered alloy can be precisely controlled. Depending on the electrochemical parameters and the configuration of the solid bodies, it is possible to influence the galvanic reactions involved, allowing the material to be recovered as a metal or metal oxide (also referred to herein as metallic oxide).

[0108] In specific cases, the recovered object may contain Li and / or Li + Cu as a main constitutive element and can serve as a reusable component, such as in batteries. By using tools like Pourbaix diagrams, the necessary electrochemical conditions for stabilizing specific element configurations can be determined, enabling the recovery of the material in different forms with tailored properties. This method offers flexibility in the recovery process, producing objects that meet specific requirements, whether as high-purity metals, metal oxides, or functional components in energy storage systems.

[0109] Fig 5. shows bar plots representing the atomic %, of the alloying (501 ) and the deposited (502) elements, detected by Energy-Dispersive Spectroscopy (EDS) of a brass plate over which different ion recovery methods have been applied. Sample 1 (Raw) reflects the initial composition of the brass plate used on Examples 1 -3. Sample 2 (S LC) has been processed through a sulfuric acid dissolution at low current density conditions, according to Example 1. Sample 3 (N HC) has been processed through a nitric acid dissolution at high current density conditions, according to Example 2. Sample 5 (S HC) has been processed through a sulfuric acid dissolution at high current density conditions, according to Example 3.

[0110] As it can be observed in Fig. 5, regarding the deposited elements presented on the row sample (501 ), in all methods shows an increase of the atomic % of Cu, as a result of the redeposited Cu atoms from the solution, and a decrease on the atomic % of Zn, as a result of the other redeposited atoms. Using nitric acid instead of sulfuric acid, and higher current densities, increases the previously described effect.

[0111] Regarding the alloying elements presented on the row sample (502), nitic based method shows high increase of the atomic % of Co, Mn and Ni. Sulfuric based method with low current density, shows high increase of the atomic % of Al, and some increase on Mn. Sulfuric based method with high current density, shows an increase of the atomic % of Al, Co and Mn.

[0112] As a consequence of the different solubility of the different ions to be recovered, the facility for the resin for capturing the ions on its structure changes, as well as the electrochemical deposition behavior over different conditions. Nitric acid shows a higher solubility potential for the used ions and also for Li ions. Using nitric acid enables the possibility of recovering all materials present in a battery in only one dissolution step while sulfuric acids does not. This surprising result enables different baths and configurations to be used as for achieving the desired level of purity, material recovery and selectiveness.

[0113] As it can be observed at Fig. 6, the image taken before the electrochemical ion recovery (Fig. 6A) process shows a homogeneous grey color, indicating the homogeneous atomic structure before the recovery. After the recovery process (Fig. 6B), areas with higher level of brightness indicates a difference of the surface composition due to electrodeposition.

[0114] In a particular embodiment of the present invention (Fig. 1 -E and Fig. 7), the electrodeposition of an ion, such as lithium is carried out into a liquid metallic solution, such as a magnesiumlithium amalgam, in order to integrate the inventive concept with the process described in US 6287448 B1 . Unlike conventional aqueous electrolysis where lithium must be maintained within strict compositional ranges to ensure amalgam fluidity, the present invention introduces the use of electrically conductive solid particles comprising ion-exchange resins as scaffolds for ion capture and release. These particles selectively retain ions, such as lithium, from the acidic aqueous phase, enabling a purifying previous step to the electrolyte containing the prior to electrochemical reduction. This reduces the sensitivity of the process to pH variations and minimizes co-deposition of transition metals.

[0115] In particular embodiments of the invention wherein lithium is the ion to be recovered, the ionexchange resins employed are functionalized with selective ligands, such as lithium-specific crown ethers (12-crown-4, 15-crown-5), cryptands, or phosphonate groups, which enable preferential complexation of lithium ions in the presence of competing species such as Ni2+, Co2+, or Cu2+derived from spent battery cathode dissolution. By immobilizing lithium ions onto a conductive resin scaffold, the subsequent electrodeposition step benefits from improved ionic selectivity, as the resin serves both as a purification medium and as a mediator for lithium-ion transfer toward the cathodic metallic solution.

[0116] During operation of a particular embodiment of lithium recovery (154), as detailed on Figure 1 E, the acidic leachate obtained from discharged battery waste (155) is first brought into contact with the functionalized ion-exchange resin particles as described in any previously detailed step from Figures 1 A - 1 D (156), where in certain embodiments the lithium ions are selectively adsorbed within the resin, while non-complexed metallic impurities remain in the solution phase. The lithium-loaded resin is then introduced into an electrochemical cell where the particles act as dispersed conductive solid electrodes (157). When an electrical potential is applied, lithium ions are released from the resin and migrate under electrophoretic forces, enabling controlled electrodeposition directly into the liquid metallic solution, such as the Mg- Li amalgam. After this step the final step (II) corresponding to US 6287448 B1 is subsequently applied (158). Any previous particular embodiment described on previous sections of the invention can be selected, combined or used during the solid bodies combination with the solution retaining the desired ion to be recovered (156) and part of the ion migration (157).

[0117] By carrying out electrodeposition directly into the amalgam phase, this embodiment circumvents one of the primary limitations highlighted in US 6287448 B1 , namely, the need to maintain the aqueous solution under strict compositional and acidity control to stabilize the lithium amalgam. Since the aqueous solution is substantially purified of transition metals and buffered by its interaction with the ion-exchange resin, fewer operational adjustments are required to control the acidity or prevent amalgam chemical deviation or contamination.

[0118] In particular embodiments, a liquid metallic solution, such as a magnesium-lithium amalgam, is selected because it provides greater stability and compatibility with lithium than mercury- based systems alone. Magnesium lowers the activity of mercury while improving the fluidity and reducing the risk of lithium oxidation during deposition. Furthermore, the use of a Mg-Li amalgam mitigates the diffusion and contamination issues associated with mercury in prior art systems. This results in a more stable cathodic substrate for lithium incorporation and higher current efficiencies.

[0119] A lithium-enriched Mg-Li amalgam produced in particular embodiment can then be used analogously to the lithium amalgam anode described in step (II) (158) of US 6287448 B1. In this step, the amalgam serves as the anode in a subsequent electrolysis process, separated by a lithium-conducting solid electrolyte from a liquid lithium cathode. Since the amalgam generated herein originates from resin-mediated deposition, it presents reduced contamination and greater compositional stability, thus enhancing the efficiency of the downstream electrolysis step.

[0120] In a particular embodiment where the lithium ions to be recovered are released from the resin under the influence of the electric field, their transfer to the liquid metal cathode is facilitated by the scaffold-like structure of the resin particles. The additional introduction of complexing ions, such as Na+, K+, or Ca2+, may be employed to weaken the bond between lithium and the functional radicals of the resin. This controlled ion-exchange mechanism reduces the energy barrier for lithium desorption, thereby enhancing ion mobility and deposition kinetics. The liberated lithium ions thus deposit more readily into the amalgam phase, ensuring high deposition rates and improved utilization of the electrical input. The adjustment of the electric potential, current density and the electrical pulsed time can be adjusted to fine tune the final amalgam composition by controlling the deposition rate.

[0121] Direct or alternate current may be used depending on the particular combination between the combination of ions to be recovered, substrate, electrolytic solvent, solid bodies nature and working conductions used in order to meet the final product specification.

[0122] In some embodiments electric pulses comprise an alternate current including a duty cycle, using current densities between 5 and 30 A / dm2.

[0123] An advantage of the embodiment described on Figures 1 E and Figure 7, is that the aqueous solution of step (I), as defined in US 6287448 B1 , is not required to remain in constant contact with the metallic amalgam. Instead, the aqueous phase is retained within the ion-exchange resin, which acts as an intermediate purification and transfer medium. This structural separation minimizes the evolution of chlorine or other anode gases from chloride solutions and alleviates the need for strict real-time pH control when lithium sulfates are used. Consequently, operational challenges associated with gas management and acidity balancing are reduced.

[0124] In some embodiments, in terms of operating conditions, the electrodeposition step is conducted at moderate temperatures (20 - 300 °C, in particular between 30 - 120eC, more in particular between 50 - 90eC ) and current densities ranging from 1-10000 A / m2, more in particular between 10 - 1000 A / m2, comparable or even lower than that of a chloralkali amalgam process. The presence of an ion-exchange resin scaffold allows for higher selectivity at lower energy inputs, reducing overall process costs. The lithium content of the Mg-Li amalgam can be adjusted more flexibly, as the controlled ion release from the resin prevents sudden concentration spikes that could otherwise solidify the amalgam or impair fluidity.

[0125] Embodiments providing a combined process that incorporates the efficiency of amalgambased lithium electrolysis described in US 6287448 B1 , while overcoming its primary limitations through the integration of conductive ion-exchange resin scaffolds and introducing lithium electrodeposition into a stabilized Mg-Li amalgam phase, enable higher selectivity, reduced contamination, simplified control of aqueous solution conditions, and enhanced lithium yield. This approach thereby advances both the environmental and industrial applicability of lithium recycling from spent battery waste streams.

[0126] In a combined embodiment, step (I) of US 6287448 B1 is modified by introducing electrically conductive solid bodies (701 ), such as ion-exchange resins, which act both as scaffolds for retaining the aqueous phase and as mediators for-ion transfer. The aqueous solution containing ions, such as lithium ions (702), derived for example from acidic leachates of spent batteries, is first captured and immobilized within the resin matrix while preventing it by being oxidized. This immobilization provides a controlled microenvironment for lithium storage while excluding a significant portion of competing metallic ions such as Cu2+, Ni2+, or Co2+. As a result, the aqueous solution held by the resin is already purified and stabilized compared to the bulk electrolyte traditionally used in step (I) of the prior art. Once loaded with lithium ions, the solid bodies (701 ) are placed in electrochemical contact with a liquid metallic cathodic phase, such as a magnesium-lithium amalgam or a mercury-based amalgam (704). A positive electrode (703) is connected to said solid bodies, while the amalgam (705) is connected to the negative electrode (704). Under the applied electric potential, the lithium ions (702) are released from the resin and migrate toward the amalgam. This process results in the direct incorporation of the ion to be recovered, such as lithium (702), into the metallic phase (705), enriching it in lithium without the operational challenges of maintaining narrow pH ranges or precise lithium concentrations in the bulk electrolyte, as required by conventional amalgam formation.

[0127] The modified step (I) illustrated in Figure 7 therefore achieves a purification of the aqueous lithium source by retention within the resin, which prevents unwanted co-deposition of transition metals, and an efficient enrichment of the amalgam phase by selective electrophoretic transfer of lithium ions. Unlike the prior art, where the aqueous phase itself must be directly electrolyzed against flowing amalgam, this approach uses the resin as an intermediate buffer that both simplifies operational control and enhances the purity of the lithium-loaded amalgam.

[0128] After the amalgam (705) has been enriched with lithium in accordance with this modified step (I), the process continues with step (II) (158) as disclosed in US 6287448 B1. In this subsequent stage, the lithium amalgam is employed as the anode, a solid lithium-ion conducting electrolyte is placed between the anode and a liquid lithium cathode, and the amalgam is kept in motion to overcome mass-transfer limitations. Because the lithium content of the amalgam is derived through resin-assisted selective deposition, it exhibits lower contamination levels and more stable composition than conventional amalgams. The combination of the resin-mediated electrodeposition step with the high-yield amalgam electrolysis of step (II) (158) constitutes the hybrid process, enabling selective, efficient, and scalable production of high-purity metallic lithium from aqueous sources and battery waste streams.

[0129] In one embodiment, the process for producing a metallic element starting from an aqueous solution of at least one metal salt comprises:

[0130] • Step (157) contacting a set of electrically conductive solid bodies comprising an ionexchange resin, retaining a solution containing at least one target metal ion to be recovered, against a liquid metallic cathodic phase comprising an amalgam, wherein the set of particles is coupled to a positive pole and the metallic cathodic phase is electrically coupled to a negative electrode, such that the at least one target metal ion to be recovered migrates from the solid bodies towards the amalgam, and thereby forming a metal-enriched amalgam; and • Step (158) electrolyzing the metal-enriched amalgam obtained from step (I) in an electrochemical cell comprising an anode formed by said amalgam, a solid electrolyte which conducts the target metal ions, and a liquid metallic cathode, wherein the amalgam anode is kept in motion, thereby recovering the metallic element.

[0131] In a particular embodiment, the process for producing metallic lithium starting from an aqueous solution of at least one lithium salt comprises:

[0132] • contacting a set of electrically conductive solid bodies comprising an ion-exchange resin, retaining a solution containing lithium ions to be recovered, against a liquid metallic cathodic phase comprising a magnesium-lithium amalgam or a mercurylithium amalgam, wherein the set of particles is coupled to a positive pole and the metallic cathodic phase is electrically coupled to a negative electrode, such that the lithium ions migrate from the solid bodies towards the amalgam, thereby forming a lithium-enriched amalgam; and

[0133] • electrolyzing the lithium-enriched amalgam obtained from step (I) in an electrochemical cell comprising an anode formed by said amalgam, a lithium-ion-conducting solid electrolyte, and liquid lithium as cathode, wherein the amalgam anode is kept in motion, thereby recovering metallic lithium with high purity.

[0134] In particular embodiments of the invention, Step (II) (158) involves the use of a lithium-ion- conducting solid electrolyte as the critical separation barrier between the lithium-enriched amalgam anode and the liquid lithium cathode. The solid electrolyte is used exclusively in Step (II), where it enables the selective transport of lithium ions while preventing electronic conductivity and blocking the passage of mercury or other amalgam constituents. This ensures that the metallic lithium recovered at the cathode is of high purity and free from heavy metal contamination.

[0135] The solid electrolyte employed in Step (II) (158) is selected to exhibit high ionic conductivity for lithium ions at the operational temperature range of 250-400 °C, while remaining chemically stable when in direct contact with both the lithium amalgam and molten lithium. In advantageous embodiments, the ionic conductivity of the material is at least 0.005 S / cm, allowing the electrolysis to be performed at current densities of several hundred to several thousand amperes per square meter without excessive voltage loss.

[0136] For this purpose, suitable solid electrolytes include lithium-P"-aluminum oxide, lithium-p- aluminum oxide, mixed lithium-p / p"-aluminum oxides, lithium analogs of NASICON ceramics, LISICON-type conductors, lithium-containing perovskite structures, and sulfidic lithium- conducting glasses. Among these, lithium-P"-aluminum oxide and lithium-based NASICON ceramics are particularly preferred due to their high stability and proven performance under chloralkali-type electrolysis conditions. These ceramics can be prepared, for example, by ionexchange from sodium analogs to lithium analogs.

[0137] In order to prevent leakage and avoid cross-contamination, the solid electrolyte is advantageously configured as a thin-walled, closed-end tube that is helium-tight and pressure resistant. The electrolyte wall is typically between 0.3 mm and 5 mm in thickness, more preferably between 1 mm and 3 mm, and most preferably about 1-2 mm. Tubes with circular or enlarged cross-sections may be used to optimize the active surface area available for lithium ion transport. A helium leak rate below 1 ■ 109mbard / s is required, ensuring that mercury or other amalgam constituents cannot diffuse through the electrolyte barrier.

[0138] In these embodiments, the lithium amalgam produced in Step (I) is maintained in motion during Step (II), for example by stirring, pumping, or mechanical circulation. This constant motion reduces mass transport limitations, ensures homogeneous amalgam composition, and allows lithium ions to be continuously supplied to the solid electrolyte interface. As a result, higher current densities can be achieved during electrolysis, typically in the range of 250-2000 A / m2, compared to only 20-50 A / m2when the amalgam remains stagnant.

[0139] Further, the operation of Step (II) (158) requires strict exclusion of water vapor, as lithium ionconducting ceramics are highly sensitive to hydration and hydrolysis under elevated temperatures. Therefore, the lithium amalgam is pretreated to remove dissolved or entrained water before being introduced into the anode chamber of the electrolysis cell. This pretreatment ensures long-term stability of the solid electrolyte and prolongs cell lifetime.

[0140] By combining these operational features, Step (II) achieves high-purity recovery of metallic lithium at the cathode, with contamination levels of mercury and other heavy metals remaining well below 1 ppm. Moreover, the current efficiency in Step (II) approaches 100% under normal polarity operation, thus enabling efficient, scalable, and industrially viable lithium recovery.

[0141] EXAMPLES

[0142] Example 1 : Ion recovery from a battery dissolved with sulfuric acid at low current deposition [Sample 2 (S LC)]

[0143] A battery cell has been discharged using a sodium chloride (NaCI) dissolution at 10 wt. % wt. The battery was immersed during 10 - 30 minutes to ensure the entire discharge. Subsequently, the battery cell has been cut and all the waste present in the battery has been manually removed. The non-polymeric materials have been immersed during 10 - 24 h under magnetic stirring at room temperature in a solution of: o 500 ml of deionized water o 200 ml of sulfuric acid (H2SO4) with a concentration of 98 wt. %

[0144] The solid phases (polymeric parts, cupper, etc.) have been separated from the liquid chemical product containing the ions to be dissolved Li, by decantation and / or filtration methods.

[0145] A mixture has been prepared for the recovery method comprising the present invention including: o 55 g of spherical particles with a heterogeneous particle size distribution ranging between 0.3 - 1.1 mm in diameter of sulfonated macroporous styrene divinylbenzene particles in an acid format after being dried up to get a constant moisture of 25 - 30 wt. % with respect to the total weight of the solid bodies. o 100 g of a solution containing approximately 44.8 wt. % of deionized water, 53.2 wt. % of H2SO4 and 0.4 wt. % Cu, 0.4% wt. Co, 0.4 wt. % Ni, 0.4 wt. % Al, 0.4 % wt. Mn obtained after the dissolution step.

[0146] The previous mixture has been subjected to tumbling during 5-10 h.

[0147] A brass plate has been used as the electrode for the deposition electrode connected to a first pole of a power supply, said power supply also connected to an iridium titanium mesh to a second pole. The two electrodes have been allocated inside a cylindrical receptacle of 350 ml containing 250 g of the previously described mixture containing the electrically conductive solid bodies filled with the presented dissolutions containing mainly Li+to be recovered.

[0148] Circular motion has been applied with an amplitude of 5 cm of radius, at 60 r.p.m.

[0149] An alternating current was applied, the brass plate acting as a cathode, at current densities ranging from 0 to 10 A / dm2, with a T- and T pause of 40 and 4 ms respectively during 2 minutes.

[0150] As a result, a coating based on Cu, Al and Mn ions has been found on the brass plate, as it can be seen on Fig. 5.

[0151] Example 2: Ion recovery from a battery dissolved with nitric acid at high current deposition [Sample 3 (N HC)]

[0152] A battery cell has been discharged using a sodium chloride (NaCI) dissolution at 10 wt. % wt. The battery was immersed during 10 - 30 minutes to ensure the entire discharge. Subsequently, the battery cell has been cut and all the waste present in the battery has been manually removed. The non-polymeric materials have been immersed during 10 - 24 h under magnetic stirring at room temperature in a solution of: o 500 ml of deionized water o 200 ml of sulfuric acid (H2SO4) with a concentration of 98 wt. % The solid phases (polymeric parts, cupper, etc.) have been separated from the liquid chemical product containing the ions to be dissolved Li, by decantation and / or filtration methods.

[0153] A mixture has been prepared for the recovery method comprising the present invention including: o 55 g of spherical particles with a heterogeneous particle size distribution ranging between 0.3 - 1.1 mm in diameter of sulfonated macroporous styrene divinylbenzene particles in an acid format after being dried up to get a constant moisture of 25 - 30 wt. % with respect to the total weight of the solid bodies. o 100 g of a solution containing approximately 89.9 wt. % of deionized water, 8.1 wt. % of HNO3 and 0.4 wt. % Cu, 0.4% wt Co, 0.4 wt. % Ni, 0.4 wt. % Al, 0.4 % wt. Mn obtained after the dissolution step.

[0154] The previous mixture has been subjected to tumbling during 5-10 h.

[0155] A brass plate has been used as the electrode for the deposition electrode connected to a first pole of a power supply, said power supply also connected to an iridium titanium mesh to a second pole. The two electrodes have been allocated inside a cylindrical receptacle of 350 ml containing 250 g of the previously described mixture containing the electrically conductive solid bodies filled with the presented dissolutions containing mainly Li+to be recovered.

[0156] Circular motion has been applied with an amplitude of 5 cm of radius, at 60 r.p.m.

[0157] An alternating current was applied, the brass plate acting as a cathode, at current densities ranging from 10 to 30 A / dm2, with a T- and T pause of 40 and 4 ms respectively during 2 minutes.

[0158] As a result, a coating based on Cu, Co, Mn and Ni ions has been found on the brass plate, as it can be seen on Fig. 5.

[0159] Example 3: Ion recovery from a battery dissolved with sulfuric acid at high current deposition [Sample 4 (S HC)]

[0160] A battery cell has been discharged using a sodium chloride (NaCI) dissolution at 10 wt. % wt. The battery was immersed during 10 - 30 minutes to ensure the entire discharge. Subsequently, the battery cell has been cut and all the waste present in the battery has been manually removed. The non-polymeric materials have been immersed during 10 - 24 h under magnetic stirring at room temperature in a solution of: o 500 ml of deionized water o 200 ml of sulfuric acid (H2SO4) with a concentration of 98 wt. %

[0161] The solid phases (polymeric parts, cupper, etc.) have been separated from the liquid chemical product containing the ions to be dissolved Li, by decantation and / or filtration methods.

[0162] A mixture has been prepared for the recovery method comprising the present invention including: o 55 g of spherical particles with a heterogeneous particle size distribution ranging between 0.3 - 1.1 mm in diameter of sulfonated macroporous styrene divinylbenzene particles in an acid format after being dried up to get a constant moisture of 25 - 30 wt. % with respect to the total weight of the solid bodies. o 100 g of a solution containing approximately 44.8 wt. % of deionized water, 53.2 wt. % of H2SO4 and 0.4 wt. % Cu, 0.4% wt. Co, 0.4 wt. % Ni, 0.4 wt. % Al, 0.4 % wt. Mn obtained after the dissolution step.

[0163] The previous mixture has been subjected to tumbling during 5-10 h.

[0164] A brass plate has been used as the electrode for the deposition electrode connected to a first pole of a power supply, said power supply also connected to an iridium titanium mesh to a second pole. The two electrodes have been allocated inside a cylindrical receptacle of 350 ml containing 250 g of the previously described mixture containing the electrically conductive solid bodies filled with the presented dissolutions containing mainly Li+to be recovered.

[0165] Circular motion has been applied with an amplitude of 5 cm of radius, at 60 r.p.m.

[0166] An alternating current was applied, the brass plate acting as a cathode, at current densities ranging from 10 to 30 A / dm2, with a T- and T pause of 40 and 4 ms respectively during 2 minutes.

[0167] As a result, a coating based on Cu, Co and Mn ions has been found on the brass plate, as it can be seen on Fig. 5.

Claims

1 . A method for ion recovery comprising: configuring a set of electrically conductive solid bodies to retain a liquid chemical product containing the ions, preferably metal ions, to be recovered; combining said solid bodies with a liquid chemical product containing the ions to be recovered, so that at least part of said ions are captured by the solid bodies; applying a voltage and / or a current density to an object electrically connected to a first pole of at least one electric source, the object being at least partially submerged in a medium comprising electrically conductive particles containing the ions to be recovered such that at least part of the surface of the object is in contact with the medium, and a container containing the medium being electrically connected to a second pole of the at least one electric source; wherein applying a voltage and / or a current density to the object, comprises applying at least one electric pulse, whereby the object is provided with at least some recovered ion, preferably with a metal ion and / or metal ion oxide.

2. The method of claim 1 , including a treatment for controlling the ions to be preferentially recovered to the combined solid bodies containing said ions, wherein the treatment includes an exchange between introduced ions and the ions to be preferentially recovered with active groups of the solid bodies, the introduced ions presenting a higher affinity to the reactive groups of the solid bodies than the ions to be preferentially recovered and a lower affinity than the ions with less recovery preference, so that a higher electrodeposition rate of the ions to be preferentially recovered is obtained upon applying an electric pulse.

3. The method of claim 1 or 2, wherein the electrically conductive solid bodies comprise a chelating resin.

4. The method of claim 1 or 2, wherein the electrically conductive solid bodies comprise an ion exchange resin.

5. The method of claim 3 or 4, wherein the ions to be recovered comprise lithium, iron and / or copper, in particular the ion to be preferentially recovered is lithium and the introduced ions for lithium preferential recovery over copper are calcium ions.

6. The method of claim 4 or 5, wherein the ion exchange resin comprises a sulfonated polystyrene divinylbenzene containing a liquid electrolyte.

327. The method of claim 6, wherein the liquid electrolyte includes an acid, in particular an acid solution, and more in particular an aqueous acid solution.

8. The method of claim 7, wherein the acid contained by the solid bodies preferably includes an acid selected from sulfuric acid, sulfonic acid, nitric acid, phosphoric and / or acetic acid.

9. The method of claim 8, wherein the method comprises dissolving the ions to be recovered in an acid solution and introducing the ions to be recovered by mixing the solid bodies with the acid solution comprising the ions to be recovered, preferably the acid concentration of the acid solution used to dissolve the ions to be recovered and included on the electrically conductive free solid bodies is between 10 and 60 wt. %, particularly between 15 - 50 wt. %, more in particular between 15 - 30 wt. %.

10. The method of any one of claims 1 to 9, wherein the electric pulses comprise an alternate current including a duty cycle, using current densities between 5 and 30 A / dm211 . The method of any one of claims 1 to 10, including a relative movement between a set of electrically conductive solid bodies and the object provided with some ion and / or ion oxide.

12. An object obtainable by applying the method of any one of claims 1 to 11 , wherein said object contains at least a portion of the ions to be recovered.

13. The object of claim 12, wherein said object is obtained in the form of an ingot-like solid shape.

14. The object of claim 13, wherein said object is obtained in the form of a coating or wherein said object is provided with a coating comprising the at least portion of the ions to be recovered.

15. The object of claim 13 or 14, wherein said object comprises a metallic alloy, metallic oxide and / or metallic oxide alloy.

16. The object of claim 13 or 14, wherein said object comprises a metal oxide.3317. The object of any one of claims 12 to 16, wherein the purity of the obtained object is between 90 - 100 wt. %, more in particular between 95 - 100 wt. % relative to the ions to be preferentially recovered.

18. The object of any claims from 12 to 17, wherein therecovered object contains lithium.

19. The object of any claims from 12 to 28, wherein the recovered object is a reusable component of a battery.

20. The object of claim 14, comprising a coating thickness ranging between 10 nm to 2 .m, particularly between 20 nm and 1.5 p.m, particularly between 30 nm and 1 p.m, and more in particular between 40 and 500 nm.21 . The method of any one of claims 1 to 11 or the object of any one of claims 12 to 20, wherein the liquid chemical product containing the ions to be recovered comprises a deep eutectic solvent (DES).

22. The method or the object of claim 21 , wherein the DES is selected from a combination of choline chloride and urea, a combination of choline chloride and glycerol, a combination of choline chloride and ethylene glycol, a combination of choline chloride and citric acid, a combination of betaine and malonic acid, a combination of menthol and decanoic acid, or mixtures thereof.

23. The method of any one of claims 1 to 11 , 21 or 22 or the object of any one of claims 12 to 22, wherein the ions to be recovered are maintained in an anhydrous medium by replacing aqueous residues with a neutral organic solvent selected from ethylene glycol, propylene glycol, butylene glycol, or dimethyl sulfoxide (DMSO).

24. The method of any one of claims 1 to 1 1 or 21 to 23 or the object of any one of claims 12 to 23, wherein desorption of the ions from the ion exchange resin is carried out in the presence of an organic acid selected from methanesulfonic acid (MSA) or acetic acid.

25. The method of any one of claims 1 to 1 1 or 21 to 24 or the object of any one of claims 12 to 24, wherein the electrically conductive solid bodies comprise titanium-oxide-derived sorbents selected from spinel-type Li4Ti50i2, layered H2TiO3or mixtures thereof.

26. The method or the object of claim 25, wherein desorption of lithium from the titaniumoxide-derived sorbents is achieved by applying mild acidic solutions or electrochemical regeneration.

27. The method of any one of claims 1 to 1 1 or 21 to 26 or the object of any one of claims 12 to 26, wherein the object is a liquid metallic amalgam, and the method comprises:(I) contacting electrically conductive solid bodies comprising an ion-exchange resin retaining a solution containing at least one target metal ion to be recovered with a liquid metallic cathodic phase comprising an amalgam, wherein the solid bodies are electrically coupled to a positive electrode and the liquid metallic phase is electrically coupled to a negative electrode, such that the at least one target metal ion to be recovered migrates from the solid bodies towards the amalgam, thereby forming a metal-enriched amalgam; and(II) electrolyzing the metal-enriched amalgam obtained in step (I) in an electrochemical cell comprising an anode formed by said amalgam, a solid electrolyte which conducts the target metal ions to be recovered, and a liquid metallic cathode, wherein the amalgam anode is kept in motion, thereby recovering the metallic element.

28. The method or the object of claim 27, wherein the target metal ion to be recovered is lithium, and the recovered metallic element is metallic lithium.

29. The method or object of claim 28, wherein the liquid metallic cathodic phase in step (I) comprises a mercury-lithium amalgam or a magnesium-lithium amalgam.

30. The method or object of claim 29, wherein the solid electrolyte is selected from Li- "- aluminum oxide, Li- -aluminum oxide, Li-p / p"-aluminum oxide, lithium analogs of NASICON ceramics, LISICON-type ceramics, perovskite-type lithium conductors, or sulfidic glasses.31 . The method or object of claim 30, wherein the solid electrolyte is formed as a helium- tight ceramic tube closed at one end and having a wall thickness between 0.3 and 5 mm.

32. The method of any one of claims 1 to 1 1 or 21 to 31 or the object of any one of claims 12 to 31 , wherein the recovered metallic object comprises metallic lithium obtained with a purity greater than 99 wt.% relative to lithium.

33. The method of any one of claims 1 to 1 1 or 21 to 31 or the object of any one of claims 12 to 32, wherein the recovery process further comprises treatment with an alternative solvent system selected from deep eutectic solvents (DES) or anhydrous protic solvents.

34. The method or object of claim 33, wherein the deep eutectic solvent comprises a combination selected from: a choline chloride and urea combination; a choline chloride and glycerol combination; a choline chloride and ethylene glycol combination; a choline chloride and lactic acid combination; a choline chloride and citric acid combination; a menthol and decanoic acid combination; a betaine and malonic acid combination; or a resorcinol and urea combination.

35. The method of any one of claims 1 to 1 1 or 21 to 34 or the object of any one of claims 12 to 34, wherein the ion-exchange system comprises a titanium-based lithium ion sieve selected from spinel-type Li4Ti50i2or layered H2TiO3.

36. The method or object of claim 35, wherein desorption of lithium from the titanium-based ion sieve is achieved by contacting the ion sieve with a mild acid solution selected from hydrochloric acid or nitric acid, or by electrochemical regeneration using the solvent systems of claim 33.36

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