Electrode activation of a desalination device

Abstract

The invention relates to electrode activation of a desalination device. A desalination cell comprises a working intercalation electrode in a first compartment, a counter intercalation electrode in a second compartment, both compartments containing a brine solution with an elevated concentration of dissolved salt, an ion exchange membrane arranged between the compartments, a voltage source arranged for supplying a voltage to the electrodes, and a sacrificial compound configured to neutralize the charge within the first compartment at a predetermined voltage upon activation of the working electrode and simultaneously being consumed by an oxidation or reduction reaction.

Description

Technical Field

[0001] This disclosure relates to electrode activation strategies and methods for desalination devices. Background Technology

[0002] The demand for high-quality drinking water is growing. However, freshwater resources on land are limited, some are depleting, and the quality of other sources is being compromised by extensive industrial and agricultural processes and urban expansion. Therefore, technologies are being developed to extract freshwater from abundant ocean waters. However, seawater or saline water contains high concentrations of dissolved salts, making it unsuitable for human consumption, agricultural use, or industrial processes. Therefore, saline water needs further desalination to reduce its dissolved solids concentration before it can be used as drinking water.

[0003] Efforts to desalinate water date back thousands of years. For example, the earliest recorded attempts included the evaporation of brine by sailors at sea. The first large-scale modern desalination process, multi-stage flash evaporation, was developed in the mid-20th century. Since then, various desalination processes have been proposed and tested. However, common problems associated with these processes, including high energy requirements, environmental considerations, and material issues related to membrane corrosion, have prevented the wider adoption of desalination.

[0004] According to one embodiment, a desalination battery pack is disclosed. The desalination battery pack includes a working intercalation electrode in a first compartment, a counter-intercalation electrode in a second compartment (both compartments contain saline aqueous solutions with elevated dissolved salt concentrations), an ion exchange membrane disposed between the compartments, and a sacrificial compound configured to neutralize the charge in the first compartment at a predetermined voltage upon activation of the working electrode and simultaneously be consumed by an oxidation or reduction reaction. The sacrificial compound may contain one or more water-soluble redox molecules. The sacrificial compound may contain one or more solid redox molecules configured as part of the working electrode body. The desalination battery pack also includes at least one outlet configured to release activation reaction products. The desalination battery pack further includes one or more valves configured to carry the sacrificial compound to the first compartment. Prior to activation, one of the electrodes may contain an alkali metal such that the alkali metal-containing electrode retains ions in a state of charge of less than about 50% prior to activation. The sacrificial compound may be water, and the predetermined voltage may be below about 0V. The sacrificial compound may have a reduction potential higher than the working electrode potential in a partially or fully intercalated state. The desalted battery pack also includes a protective layer formed by reaction products on the working electrode, the counter electrode, or both, to stabilize the electrodes during battery pack operation.

[0005] In an alternative embodiment, a method for activating the working electrode of a desalted battery pack is disclosed. The method includes providing a desalted battery pack comprising a working intercalation electrode and a counter-intercalation electrode, each electrode disposed in a separate compartment containing a saline aqueous solution with an elevated concentration of dissolved salts. The battery pack also includes an ion exchange membrane disposed between the compartments. Prior to operation of the battery pack, the method includes providing a predetermined voltage to the working electrode to (a) deintercalate ions from the electrode into the compartment, thereby increasing the ion shuttle capacity of the electrode, or (b) intercalate ions from the compartment into the electrode, thereby decreasing the ion shuttle capacity of the electrode. The method includes reducing or oxidizing a sacrificial compound to neutralize the charge in one of the compartments. The sacrificial compound may comprise one or more solid redox molecules configured as part of the working electrode body. The method may further include releasing one or more activation reaction products via at least one discharge port. The method may further include delivering the sacrificial compound to the compartment via at least one valve. The method may include increasing the ion shuttle capacity from about 50% or less of the pre-activation capacity to about 100%. The method may further include adjusting the pH in the compartment by adding a pH-adjusting medium to at least one of the compartments. The desalination battery pack may also include forming a protective layer on the working electrode and / or counter electrode to stabilize the electrodes used for battery pack operation.

[0006] In another embodiment, a method for activating a desalinated battery pack with electrodes is disclosed. The battery pack includes an electrode configuration that achieves approximately 100% / 0% state of charge balance by rebalancing the ion shuttle capacity of the electrodes, wherein each electrode is arranged in a separate compartment containing a saline aqueous solution. This is achieved by applying a predetermined voltage to the electrodes to release ions from one or more of the electrodes into the solution or to attract ions from the solution to one or more of the electrodes, and by providing at least one sacrificial compound to be reduced or oxidized while simultaneously neutralizing the charge generated by the applied voltage. The sacrificial compound may comprise one or more solid, soluble, or dissolved redox molecules. The method may further include releasing activation reaction products via at least one discharge port and delivering the at least one sacrificial compound to the compartment via at least one valve, or both. The at least one sacrificial compound may have a reduction potential higher than the working electrode potential in a partially or fully embedded state. Attached Figure Description

[0007] Figure 1 A schematic diagram of a desalination battery pack cell according to one or more embodiments is depicted.

[0008] Figure 2 Electrode balance curves at various shuttle capacities are schematically depicted.

[0009] Figure 3-6 The principle of electrode activation using one or more sacrificial compounds A is schematically depicted. Detailed Implementation

[0010] The following describes embodiments of this disclosure. However, it should be understood that the disclosed embodiments are merely examples, and other embodiments may take various and alternative forms. The drawings are not necessarily to scale; some features may be exaggerated or minimized to show detail of particular components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as a representative basis for teaching those skilled in the art to use embodiments of the invention in various ways. As will be understood by those skilled in the art, various features shown and described with reference to any of the drawings may be combined with features shown in one or more other drawings to produce embodiments not explicitly shown or described. The combinations of features shown provide representative embodiments for typical applications. However, various combinations and modifications of features consistent with the teachings of this disclosure may be desired for a particular application or implementation.

[0011] Unless otherwise expressly indicated, all numerical quantities representing dimensions or material properties in this specification should be understood to be modified by the word “about” when describing the broadest scope of this disclosure.

[0012] The initial definition of acronyms or other abbreviations applies to all subsequent uses of the same abbreviation herein, with necessary modifications to suit the normal grammatical variations of the originally defined abbreviations. Unless explicitly stated otherwise, performance is measured by the same technique referenced previously or later for the same performance.

[0013] The terms “substantially” or “about” are used herein to describe the disclosed or claimed embodiments. The terms “substantially” or “about” may modify values ​​or relative characteristics disclosed or claimed in this disclosure. In this case, “substantially” or “about” may mean that the value or relative characteristic it modifies is within ±0%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, or 10% of said value or relative characteristic.

[0014] A description of a group or class of materials applicable to a given purpose in relation to one or more embodiments implies that a mixture of any two or more members of that group or class is suitable. A description of components in chemical terms refers to the components when added to any combination listed in the specification, and does not necessarily exclude chemical interactions between the components of the mixture once mixed. The first definition of an acronym or other abbreviation applies to all subsequent uses of the same abbreviation herein, with necessary modifications to the normal grammatical variations applicable to the originally defined abbreviation. Unless expressly stated to the contrary, measurements of performance are determined by the same technique referenced previously or later for the same performance.

[0015] The world's growing population is creating an ever-increasing demand for clean freshwater for consumption, agriculture, and industry. Freshwater is defined as an aqueous solution with a low salt concentration (typically less than 1%). Due to limited freshwater resources, numerous attempts have been made to produce freshwater from abundant ocean water through desalination. Desalination is the process of removing mineral components from brackish water. Removing salts and other chemicals from brackish water requires electrical or thermal energy to separate the brackish water into two streams: a freshwater stream containing a low concentration of dissolved salts and a concentrated brine stream with a high concentration of dissolved salts.

[0016] Various desalination technologies have been developed, such as evaporation, freezing, distillation, reverse osmosis, ion exchange, and electrodialysis. However, all of these technologies have certain drawbacks that hinder their widespread use and limit their success. For example, reverse osmosis typically requires a large electrical input, making the technology quite expensive. Additionally, reverse osmosis utilizes selective membranes, which are prone to scaling or unwanted accumulation of mineral deposits on their surfaces. Therefore, these membranes require frequent replacement, leading to increased maintenance needs and costs.

[0017] Electrodialysis is another membrane desalination technology that uses ion-exchange membranes. Electrodialysis can be expensive and offers no barrier against microbial contamination. However, membrane-free technologies present other challenges. For example, freeze-thaw cycles typically rely on extended periods of naturally sub-zero temperatures, thus limiting their application to certain climatic conditions. Multi-effect distillation utilizes several stages or effects in which the feed water is heated by steam in a tube through which brine is sprayed. However, this technology suffers from high operating costs unless waste heat can be utilized in the desalination process, and the high temperatures can increase corrosion and scaling.

[0018] One of the newly developed concepts is an electrochemical method for desalination, such as a desalination battery pack or electrochemical device. The desalination battery pack uses electrical energy input to extract sodium and chloride ions, as well as other impurity ions, from brackish water to produce fresh water. The battery pack thus employs a dual-ion electrochemical deionization technology, including sodium and chloride dual-ion electrochemical electrodes to which a voltage is applied to separate the brackish water into fresh water and concentrated brine streams with relatively low concentrations of dissolved salts.

[0019] A water treatment system utilizing a desalination battery pack is desired. Non-limiting examples of such a system may include a container for holding a liquid solution such as brackish water or desalinated water, two electrodes, a power source, a brackish water inlet, and a fresh water outlet. Additional components such as additional inlets and outlets may be considered. The two electrodes may be separated by an exchange membrane. The exchange membrane may be a cation exchange membrane or an anion exchange membrane. The exchange membrane may include a separator on one or both sides.

[0020] The container can be any shape, size, or construction, including containers, compartments, enclosures, vessels, cans, jars, tanks, troughs, etc., capable of acquiring, retaining, holding, and / or releasing liquid solutions such as brackish water, saline water, seawater, ocean water, fresh water, sweet water, drinking water, desalinated water, polluted water, industrial water, etc. The container is sufficiently spacious to hold a sufficient volume of the desalination solution; therefore, the size varies depending on the specific application. The container can be large enough to serve industrial applications. The container can be made of various materials capable of withstanding corrosion, temperature fluctuations, pH changes, pressure changes, and resisting other chemical, mechanical, and / or physical conditions.

[0021] The container may be made of glass, plastic, composite materials, metal, ceramic, or a combination of materials. The container may feature one or more protective coatings. The container may be made of materials that minimize water contamination. The container may be made of one or more non-toxic materials that meet drinking water standards.

[0022] The electrodes are arranged within the battery pack to be in fluid communication with the aqueous solution present in the container. The electrodes are at least partially immersed in the aqueous solution. The electrodes may be completely immersed in the aqueous solution. The electrodes may be placed on opposite sides of the container, centrally within the container, or both may be located on the same side of the container. The electrodes may be placed adjacent to each other, or spaced apart by a distance in the presence of one or more separators and exchange membranes (anion exchange membranes or cation exchange membranes). This distance may be 1 mm or greater, 1 cm or greater, 10 cm or greater, 20 cm or greater, or 30 cm or greater, depending on the dimensions of the battery pack module and stack system, the container, and the electrodes.

[0023] The electrodes of the battery pack serve as embedding bodies. Embedding refers to the reversible inclusion of one or more ions into a material with a layered structure. The spaces between the layers can be used for the temporary storage of one or more types of ions. The first and second embedding bodies reversibly store and release ions from a material having a first dissolved salt concentration. c 1 The cations and anions in the saline aqueous solution are used to generate a second dissolved salt concentration within the container. c 2. Fresh water or desalinated water solutions and solutions with a third dissolved salt concentrationc A 3% salt solution, in which c 3 > c 1 > c 2 .generally, c 1 The dissolved salt concentration can be approximately 500 to 10,000, 800 to 7,000, or 1,000 to 5,000 ppm, depending on the source of the saline water. c 1 This is related to the increased dissolved salt concentration in saline water. The battery pack can reduce the amount of dissolved salt to approximately 15 to 250, 30 to 150, or 50 to 100 ppm. c 2 .

[0024] Depending on operating conditions and device design, the electrodes can be made of the same or different materials. The first, second, or both electrodes can be made of expanded graphite. Graphite is a crystalline allotrope of carbon and an example of a half-metal. Graphite exhibits the most stable form of carbon under standard conditions. Graphite is an electrical conductor with highly anisotropic acoustic and thermal properties and is self-lubricating. Graphite has a layered planar structure. The individual layers of graphite are called graphene. In each layer, carbon atoms are arranged in a honeycomb lattice with a natural spacing of 0.142 nm. The interlayer spacing of pristine graphite is 0.335 or 0.34 nm. The atoms in the plane are covalently bonded, but the bonding between graphene layers is provided by weak van der Waals bonds.

[0025] Due to its unique properties and structure, graphite has been used as an anode electrode material in lithium-ion battery packs. However, these applications typically involve virgin graphite. It is well known that virgin graphite, with a layer spacing of 0.34 nm in the z-direction between graphene layers, is unsuitable for different types of battery packs, namely Na-ion battery packs (NIB), because virgin graphite has low Na+ content. + Ion capacity. Due to Na + Due to the relatively large size and steric effect of the ions, Na+ has a higher ion size compared to other elements in the same column of the periodic table, namely other alkali metals. + The chemical bonds with pristine graphite are typically weak. For example, Na... + The ions have a higher concentration than Li. + A larger radius may hinder the electrochemical process of Na + Mass transfer of ions.

[0026] Therefore, the electrode may contain elements sufficient to accommodate Na. +Expanded graphite with interlayer spacing of ions. The expanded graphite can be formed by altering and / or increasing the interlayer spacing of the original graphene layers. Different expansion methods can result in interlayer spacings tailored to specific applications. When the graphene layers expand to such that the expanded graphite interlayer spacing is greater than 0.34 nm, particularly to 0.43 nm or greater, Na… + Ions and / or other ions can be reversibly intercalated into and extracted from expanded graphite, thereby delivering a relatively high reversible capacity of >~280 mAh / g at a current density of 10 mA / g. By using expanded graphite instead of pristine graphite, the sodium ion storage capacity can thus be increased by at least about 20 to 30 times.

[0027] The interlayer spacing of graphene layers can be customized to provide sufficient storage capacity for various anions, cations, or both. The interlayer spacing between graphene layers can be significantly uniform or substantially uniform. If well controlled by the synthesis conditions, the interlayer spacing along the entire length of the graphene layer can be uniform.

[0028] In the expanded graphite disclosed in this paper, the interlayer spacing in the z-direction between graphene layers is... d s Spattings can be greater than approximately 0.34 nm, 0.35 nm, 0.36 nm, 0.37 nm, 0.38 nm, 0.39 nm, 0.40 nm, 0.41 nm, 0.42 nm, 0.43 nm, 0.44 nm, 0.45 nm, 0.46 nm, 0.47 nm, 0.48 nm, 0.49 nm, 0.50 nm, 0.51 nm, 0.52 nm, 0.53 nm, 0.54 nm, 0.55 nm, 0.56 nm, 0.57 nm, 0.58 nm, 0.60 nm, 0.61 nm, 0.62 nm, 0.63 nm, 0.64 nm, 0.65 nm, 0.66 nm, 0.67 nm, 0.68 nm, 0.69 nm, 0.70 nm, or larger. This refers to the interlayer spacing of expanded graphite. d s The interlayer spacing of expanded graphite can be approximately 0.37 to 0.45 nm, or approximately 0.45 nm to 0.6 nm. d s The nanometer diameter can be approximately 0.37 to approximately 0.7 nm, approximately 0.43 to approximately 0.6 nm, or approximately 0.45 to approximately 0.55 nm. Different oxygen functional groups in the graphene sheet can help control the interlayer spacing. d s The oxygen functional group may include groups such as -OH, =O, -O-, -COOH, etc., or combinations thereof. The interlayer spacing can be precisely controlled by these functional groups. d sprepared by solution-based methods and / or heat treatment.

[0029] Due to the enlarged interlayer spacing, expanded graphite can absorb cations and anions from saline water, seawater, brackish water, etc. Expanded graphite can absorb cations, including but not limited to Na + , Mg 2+ , Al 3+ , Si 4+ , K + , Ca + , Sc 3+ , Ti 2+ / 3+ / 4+ , V 2 + / 3+ / 4+ / 5+ , Cr 3+ / 6+ , Mn 2+ / 3+ / 4+ , Fe 2+ / 3+ , Ni 2+ / 3+ / 4+ , Cu 2+ , Zn 2+ , Sn 2+ / 4+ , Pb 4+ etc., and anions, including but not limited to monoanionic species such as F - , Cl - , Br - , I - , S - / 2- , anion complexes such as ClO 4- , ClO 3- , ClO 2- , BrO 4- , BrO 3- , SO4 2- , SiO3 2- , CN - , metal-containing anions such as MX y O z n- (where M = Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Mo, Sn, Cs and Pb; X = F, Cl, Br, I, N and P; and 0 < y ≤ 5; 0 ≤ z ≤ 5; 1 ≤ n ≤ 4) etc.

[0030] The enlarged interlayer spacing of expanded graphite even allows ions with relatively large radii such as Na + to be attracted into the space defined by the graphene layers, temporarily retained therein, and later released. The expanded graphite thus accommodates one or more ions as guests. For example, the intercalation material may include one or more of the following active materials: A x CuFe(CN)6, where A = Li, Na, K, Cs and 0 ≤ x ≤ 1, A xMnFe(CN)6, where A = Li, Na, K, Cs and 0 ≤ x ≤ 1, A x MnMn(CN)6, where A = Li, Na, K, Cs and 0 ≤ x ≤ 1, A x ZnFe(CN)6, where A = Li, Na, K, Cs and 0 ≤ x ≤ 1, A x BaFe(CN)6, where A = Li, Na, K, Cs and 0 ≤ x ≤ 1, Ti x Fe 1-x [Fe(CN)6] 0.96 Where 0≤x≤1, polyimide (PNDIE), FePO4, NaMnFe2(PO4)3 sodium phosphate manganese ore, Na3Fe3(PO4)4, Na(M)PO4, where M=Fe, Mn, or Fe x Mn 1-x And 0≤x≤1, MnO2, Na x MnO2, where 0≤x≤1, ZnMn2O4, MgFeSiO4 / C, Mg x Mn 2-x SiO4, where 0≤x≤2, Mg 0.5 Ti2(PO4)3, LiTi2(PO4)3, Ti x Al 2-x (PO4)3, where 0≤x≤2, TiP2O7, Na3MnTi(PO4)3, K2Ti4O9, TiS2, FeS2, CaMO3, where M=Mn and / or Fe, potassium terephthalate, potassium 2,5-pyridinedicarboxylate (K2PC), KFeF3, K 0.3 MnO2, KMg x Fe 2-x (PO4)2, where 0≤x≤2, A x FeFe(CN)6, where A = Li, Na, K, Cs and 0 ≤ x ≤ 1, A x NiFe(CN)6, where A = Li, Na, K, Cs and 0 ≤ x ≤ 1, NaTi2(PO4)3, Na2FeP2O7, TiO2, Na2Ti3O7.

[0031] The cation-intercalating active material can be doped or undoped cubic spinel MnO2, Na4Mn9O2, etc. 18 (or equivalently Na) 0.44MnO2), orthorhombic materials with tunnel structures, and NaM2(PO4)3 (where M = Ti, Mn, Fe, Ni, Cu or a combination thereof), wherein the exact composition of Na can be controlled by thoroughly mixing different starting amounts of Na2CO3 or NaOH with a metal oxide precursor and then heat-treating at a high temperature (approximately 800°C). Partial substitution of Na in these structures with Li, Mg, Ca, and / or K is permitted.

[0032] In addition, the cation intercalation material used as the electrode may include, but is not limited to, Na. 0.44 Mn₂O₄, NaMnO₂, K 0.27 MnO2, Na 2 / 3 Ni 1 / 4 Mn 3 / 4 O2, γ-MnO2, Na3V2(PO4)3, Na2VTi(PO4)3, NaVPO4F, Na2V6O 10 · x H2O, Na 0.66 [Mn 0.66 Ti 0.34 O2, MoO3, Na2FeP2O7, Na3TiMn(PO4)3, Na3V2O2(PO4)2F, etc., or combinations thereof. The cationic intercalation host material may include Prussian blue and / or Prussian blue analogues—compounds based on hexacyanoferrate (HCF) or hexacyanomanganate (HCM) such as NiHCF, NiCuHCF, and MnHCM.

[0033] On the other hand, the intercalating material can be specifically used for anions. The anion-intercalating active material may include AgCl, FeCl3, C3N4, FeOCl, BiOCl, VOCl, Mg(ClO2)2·6H2O, MgCl2O, NaClO2·3H2O, and at least one of the following ternary and quaternary metal oxides and metal chloride oxides: AlH 12 (ClO2)3, MnH8(ClO2)2, FeH8(ClO2)2, and NiH8(ClO2)2, and at least one of the following alkali metal-based and transition metal-based chlorine oxides and their hydrates: Ca4Cl6O, CaHClO, NaH4ClO2, AlClO, Si3(Cl4O)2, SiCl2O, Si6Cl 10 O7, SiCl2O, Si2Cl2O3, Ti(ClO4)4, TiClO, Mn8Cl3O 10 , MnH4(ClO)2, FeClO, Ni(ClO4)2, NiH 16 (ClO8)2、NiH 12(ClO3)2, Cu2Cl2O and CuH8(ClO5)2, or combinations thereof.

[0034] The loading of the embeddable active material in the cathode, anode, or both can be from about 0.01 to 100 mg / cm³. 2 0.05 to 50 mg / cm 2 or 0.1 to 10 mg / cm 2 .

[0035] In addition to the active material, one or both of the electrodes may contain one or more conductive agents, one or more polymeric binders, and / or other components. The electrodes(s) may contain active material in an amount of about 70 to 99% by weight, 75 to 97% by weight, or 60 to 95% by weight, based on the total weight of the electrodes. The electrodes(s) may contain one or more conductive agents in an amount of about 1 to 40% by weight, 2.5 to 30% by weight, or 5 to 20% by weight, based on the total weight of the electrodes. The electrodes(s) may contain one or more polymeric binders in an amount of about 1 to 30% by weight, 2.5 to 20% by weight, or 5 to 15% by weight.

[0036] Non-limiting examples of conductive agents may include carbon black, conductive carbon black, amorphous carbon, carbon fiber, one or more quaternary ammonium salts, one or more alkyl sulfonates, one or more halogen-free cationic compounds, or combinations thereof.

[0037] Non-limiting examples of polymeric adhesives include polyvinylidene fluoride (PVdF), polyacrylonitrile (PAN), poly(methyl methacrylate) (PMMA), polyethylene glycol (PEO), polyimide, polydopamine, poly(ethylene glycol) diacrylate, polymethylpentene, nylon, metal-aromatic polyamide, polyetherimide, copolyester, polyetherketone, carboxymethyl cellulose, styrene-butadiene rubber (SBR), copolymers and blends such as poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP), poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP), etc. Poly(ethylene-chlorotrifluoroethylene) (PVdF-CTFE), poly(methyl methacrylate-vinyl acetate) (PMMA-VAc), poly(ethylene glycol) diacrylate (PEGDA), poly(methyl methacrylate-acrylonitrile-vinyl acetate) (PMMA-AN-VAc), poly(methyl methacrylate-co-butyl acrylate) (PMMA-co-BA), poly(3,4-ethylenedioxythiophene) polystyrene sulfonate-co-polyethylene glycol (PEDOT-co-PEG), etc., or combinations thereof.

[0038] Additionally, the electrode(s) may contain one or more pillaring agents. Pilling agents or dopants refer to various compounds that can be incorporated into the electrode structure through chemical modification of the active material. For example, the pillaring agent may be chemically and / or mechanically bonded to the individual graphene layers of the expanded graphite. The one or more pillaring agents may be incorporated between adjacent graphene layers within the expanded graphite, and / or configured to maintain a predetermined specific interlayer spacing between adjacent layers. d s .

[0039] The columnar adsorbent can further enhance mass transfer and / or selectivity in the ion adsorption and desorption processes within the battery pack. For example, incorporating sulfur as a columnar adsorbent can result in the attraction of a larger proportion of cations. Alternatively, modifying the electrode active material with a positively charged metal or metal oxide can lead to increased attraction for anions and repulsion of cations. The columnar adsorbent can thus help to modulate the chemistry of the desalinated water to obtain the desired drinking water chemistry. For example, in regions where the seawater to be desalinated contains undesirable amounts of anions and / or desired amounts of cations, a positively charged columnar adsorbent can be incorporated to attract the anions to be inserted, leaving a larger amount of cations in the aqueous solution. The desalinated water can therefore be tailored to local needs and drinking water regulations.

[0040] For neutral water with a pH of approximately 7-8, compared to a standard hydrogen electrode (SHE), this electrode can operate within a water stability window of approximately -0.5 to 1.5 V, -0.4 to 1.2 V, -0.3 to 1.1 V, or 0 to 0.9 V (or relative to Na / Na). + It operates within a range of 2.2 to 3.6 V to store one or more of the aforementioned types of ions. Lower pH values ​​can shift the voltage higher (up to +0.4 V at pH = 0), while higher pH values ​​can shift the voltage lower (down to -0.4 V at pH = 14).

[0041] The actual ion storage capacity of an electrode can vary depending on factors such as operating voltage conditions, the concentration of ions present in the aqueous solution, the overall chemical composition of the aqueous solution, the acidity of the aqueous solution, and the ohmic resistance or any other type of resistance within the battery pack. For example, because seawater in different regions of the world has varying ion concentrations, the actual ion capacity of the electrode can differ based on location.

[0042] The salt adsorption capacity of the electrode can be approximately 1 to 300, 5 to 150, or 10 to 100 mg salt / g active electrode material. The electrode area can be approximately 10 to 500, 50 to 350, or 100 to 250 cm². 2The electrode thickness can be approximately 2.5 to 500, 5 to 400, or 10 to 300 μm, depending on the choice of electrode material, porosity, tortuosity, viscosity of the slurry containing the electrode material, and the actual composition ratio of (one or more) active material: binder: carbon. The electrode porosity can be approximately 20 to 80, 30 to 70, or 40 to 60%. The electrode density can be 0.1 to 5, 0.25 to 4, or 0.5 to 3 g / cm³. 3 This depends on the particle size, microstructure, hardness of the material, and the amount of carbon added to the electrode system.

[0043] The charging time for the battery pack used for water cleaning can be approximately 1 to 60 minutes, 5 to 45 minutes, or 15 to 30 minutes, depending on the capacity. The discharge time for electrode cleaning can be approximately 50% to 100% of the charging time, i.e., approximately 30 seconds to 60 minutes, 2.5 to 45 minutes, or 7.5 to 30 minutes. Depending on the number of batteries included in the battery pack module, the typical flow rate during charging can be approximately 0.5 to 5000 L / min, 1 to 2500 L / min, or 5 to 2000 L / min. The water recovery rate can be greater than approximately 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95%. The exact water flow rate can be controlled by a pump as described below.

[0044] The electrodes can be separated by an exchange membrane. The exchange membrane may include septa on one or both sides. The exchange membrane may be a cation exchange membrane or anion exchange membrane.

[0045] The exchange membrane can be an anion exchange membrane (AEM). An AEM can comprise graphene, graphene oxide, or both, composed of oxygen functional groups rich in hydroxyl (-OH) groups. Specific functional groups in graphene oxide, such as hydroxyl (-OH), carboxyl (-COOH), carbonyl (=O), epoxy (-O), or combinations thereof, allow cations (i.e., Na+) to be present. + K + Mg 2+ Ca 2+ Pb 2+ (etc.) adsorbs and desorbs within a relatively stable voltage window, such as 1.0 to 1.5 V or 0.401 to +1.23 V relative to SHE. Conversely, due to the electron repulsion between the anion itself and the oxygen functional groups (-OH, -COOH, =O, and -O-) of graphene oxide, the anion absorption voltage is very high. Unless a very large voltage greater than 3V is applied to the system, anions such as F... - Cl - ,Br - I - or S 2- and anionic complexes, including but not limited to ClO4- ClO3 - ClO2 - BrO4 - BrO3 - SO4 2- SiO3 2- or CN - The negatively charged oxygen functional groups in the AEM material freely move to the other side of the membrane due to repulsion. Therefore, the functionalized graphene oxide layer can be used as a selective ion exchange membrane that allows only anions to pass through.

[0046] The AEM may comprise a mixture of graphene oxide and other electronically conductive polymers, including polyethylene oxide (PEO), poly(pyrrole) (PPY), polyaniline (PANI), poly(thiophene) (PT), poly(3,4-ethylenedioxythiophene) (PEDOT), poly(p-phenylene sulfide) (PPS), polyacetylene (PAC), and poly(p-phenylene vinylidene) (PPV), or combinations thereof. Furthermore, the AEM may be composed of a mixture of graphene oxide and other polymers that are ionicly conductive rather than electronically conductive, including cross-linked polyvinyl alcohol (PVA), cross-linked polymethyl methacrylate (PMMA), polyphenylene vinylidene (PPV), or combinations thereof. Additional electronically conductive materials, such as graphite, hard carbon, soft carbon, carbon black, or combinations thereof, may be added as needed.

[0047] The battery pack or capacitive deionization device further includes a power source, current source, or voltage source capable of supplying current to the electrodes and / or exchange membrane. Current is applied to remove various ions from the water contained in the container. The applied voltage V and membrane voltage Vm can be used to control selective ion permeability and affect the overall efficiency of the water desalination method. The current can be a constant current until a predetermined voltage cutoff is reached, or a positive voltage can be applied to the battery pack. Applying a controlled membrane voltage Vm can enhance cation rejection and anion diffusion through the exchange membrane. The membrane voltage can be 0 to ±0.5 V.

[0048] Figure 1 The image depicts a non-limiting example of a battery pack 100 for use in a water treatment device. The battery pack 100 includes two electrodes 102 and 104 and an anion exchange membrane 106 disposed between the electrodes 102 and 104. The anion exchange membrane (AEM) 106 separates two separate water compartments 108 and 110. The electrodes 102 and 104 are connected to a voltage source 112. The battery pack 100 also includes one or more water inlets 114 and water outlets 116.

[0049] The inlet 114 and outlet 116 can be used to introduce or release brine or desalinated water. The number of inlets 114 and outlets 116 in each compartment 108, 110 can be the same or different. For example, the first compartment 108 may have one more inlet than the second compartment 110. One or more inlets 114 may be located between the AEM 106 and the embedded bodies 102, 104. The inlet 114, outlet 114, or both may be centrally located between the AEM 106 and the body electrodes 102, 104. The inlet 114 may be located directly opposite the outlet 116. Alternatively, the inlets 114 and outlets 116 in the same compartment 108 or 110 may be staggered, such that the inlets 114 and outlets 116 are not aligned, not on the same axis, not centrally located between the AEM 106 and the electrodes, or a combination thereof. The at least one inlet 114, outlet 116, or both may have the same or different diameters. Inlet 114, outlet 116 or both can connect battery pack 100 to reservoir 222, reservoir 223, additional reservoir or a combination thereof.

[0050] Furthermore, the battery pack 100 and auxiliary battery packs disclosed herein can be connected to one or more water reservoirs 122 for storing brackish or desalinated water, one or more pumps 124 capable of controlling the flow rate of water into and out of the battery pack 100, valves 126 connected to one or more pumps 124, and / or one or more devices 128 capable of checking, measuring, or monitoring water quality, such as pH meters, water softeners, etc. The reservoir 122 can be a container, compartment, enclosure, vessel, tank, jar, trough, etc. of any shape, size, or construction capable of obtaining, retaining, holding, and / or releasing a liquid solution, such as brackish water, brackish water, seawater, ocean water, fresh water, sweet water, drinking water, polluted water, industrial water, etc. The pumps 124 can be automatic, manual, or both. The pumps 124 can be located in the inlet, outlet pipe, or a combination thereof connected to the water reservoir 122.

[0051] Alternatively or additionally, post-processing steps may be performed to further neutralize and / or adjust the water according to the requirements of a specific application.

[0052] The battery pack 100 may include two symmetrical electrodes 102, 104 comprising electrode materials with the same or similar chemical properties and loads. Alternatively, the battery pack 100 may be characterized by an asymmetric electrode configuration, such that the first electrode 104 is at least partially or entirely made of a material different from that of the second electrode 106, the first electrode 104 having a different load of the same or different material as the second electrode 106, or a combination thereof. The electrode materials may share similar structural features such as the same space group, but ions such as Na+... + Ca 2+ or Mg +The concentration can vary. In one non-limiting example embodiment, one of the electrodes can be made of a chemically delithiated intercalating host material, such as Na. x Made of MnO2, where x < x 最大 The initial concentration of the alkali metal within the alkali metal oxide is represented by x. A non-limiting example of an asymmetric electrode may include an electrode comprising FeFe(CN)6 and a second electrode comprising NiFe(CN)6.

[0053] Once activated, the battery pack 100 can operate as follows: A positive voltage V can be applied to the battery pack 100 to release cations such as Na from one of the electrodes 102 and 104. + The cations are dispersed together with brine in one of the water compartments 108 and 110, particularly the brine compartment 118, which contains a first dissolved salt concentration. c 1 A saline aqueous solution. The saline water in the saline compartment 118 can be supplied through one of the water inlets 114. Since cations cannot pass through the anion exchange membrane 106, the Na+ in the saline compartment 118... + Concentration increases. Anions such as Cl... - The cations are attracted and pass through the anion exchange membrane 106 to neutralize the cations in the brine compartment 118. Simultaneously, due to charge neutralization and the applied bias voltage, cations such as Na+... + Ions are inserted into the other side of electrodes 102 and 104. This process produces anion exchange membrane 106 containing a second dissolved salt concentration on the opposite side. c 2 Clean water compartment 120 containing fresh water or desalination solution, wherein c 1 > c 2 .

[0054] The battery pack 100 can be a closed or open system. The battery pack 100 can operate in a cyclic manner (embedding and de-embedding) with continuous water flow. In continuous flow, demineralized water from the clean water compartment 120 can be stored in a reservoir 122. Alternatively, the battery pack 100 can operate as an intermittent demineralization device, where a limited amount of water can be supplied to the compartments for cleaning on a smaller scale. Alternatively or additionally, a semi-continuous flow of water can be supplied to the battery pack 100 so that the water compartments 108, 100 can be refilled with additional brine and can operate in the opposite direction in the next cycle. In an alternative embodiment, the battery pack 100 can be designed as a cylindrical tubular battery. Both compartments 108, 100 can be used for water purification in opposite operating directions.

[0055] In a non-limiting example, continuous collection of clean water in a continuous cycle can be provided by utilizing a clean water reservoir 122 and a circulation loop for water purification. During startup, the two electrodes 102, 104 are at similar states of charge (SOC) (e.g., 50%), then the first electrode 102 discharges (to 0%) and the second electrode 104 charges to 100% SOC. The process is schematically depicted in... Figure 2 (Activation state 3). In the first cycle, Na can be removed from electrodes 102 and 104 containing the embedded host material. + K + Mg 2+ Ca 2+ and Pb 2+ The first target ion is added. Due to cation-anion attraction (neutral), anions are added to the brine compartment 118. The clean water compartment 120 thus contains collectable demineralized water. The next cycle allows ions to be flushed out of electrodes 102, 104, and wastewater to be discharged. Electrodes 102, 104 can also be used in the next water purification cycle.

[0056] The desalinated water can be circulated in the battery pack 100 one or more times to further purify the water and achieve a predetermined dissolved salt concentration. c x ,in c x ＞c 2 .

[0057] The battery pack 100 and its electrodes 102 and 104 are activated. The two electrodes 102 and 104 may be partially or completely filled with alkali metals (x > x) before operation. 最小 () or partially or completely free of alkali metals (x < x) 最大 The activation process enables the battery pack 100 to effectively utilize the rocking chair concept, allowing charge carriers to shuttle back and forth between the two embedded electrodes 102, 104. The activation can be achieved through various methods as disclosed herein.

[0058] When one electrode is completely filled with alkali metal or at 100% capacity, while the other electrode is completely free of alkali metal or at 0% capacity ( Figure 2 The activation target can be achieved when both electrodes are 50% filled with alkali metal or at 50% capacity, so that the state of charge (SOC) between the electrodes is balanced at 50% / 50%. Figure 2 (Activation state 3 in the text). While a 0% / 100% balanced configuration may be more practical and easier to control, other configurations may also be considered.

[0059] Figure 2 A graph showing the electrode balance between the state of charge (SOC) of the working electrode and the state of charge (SOC) of the counter electrode is presented. As can be seen, Figure 2 An ideal equilibrium path for ion insertion and removal is shown in a cycling process without capacity loss. Figure 2 The electrode balance is shown before activation (starting points 1 and 2, dots), after activation (stars), and under aging conditions (dashes indicate irreversible conditions, dotted lines indicate reversible conditions).

[0060] The activation process shall not cause any mechanical, thermal, or chemical damage to the electrodes, battery pack, or any of its components. For example, the activation process should avoid processes that are harmful to the battery pack in any way, such as carbon oxidation when using carbon electrodes.

[0061] The concentration of alkali metals can be chemically controlled, such as by a synthesis or pre-leaching process, or electrochemically controlled, such as by ion insertion or deintercalation, or both. The activation process can therefore be achieved by one or more of the methods or strategies disclosed herein, or combinations thereof. Thus, the following activation strategies are disclosed herein: (1) the addition / utilization of at least one or more redox sacrificial compounds, providing activation strategies such as: (a) water oxidation / reduction, (b) the addition of at least one or more soluble redox molecules to an aqueous stream, which are sacrificially oxidized / reduced when a voltage is applied to avoid water redox and electrode corrosion, (c) the addition of at least one or more soluble redox molecules to an aqueous stream, which undergo oxidation / reduction when in contact with one or more inserted or deintercalated electrodes, (d) the addition of at least one or more solid redox molecules to an electrode, which are sacrificially oxidized / reduced when a voltage is applied, or (e) the addition of at least one or more redox molecules / solid compounds that form a desired interface with the inserted electrode through their solid, liquid, or gaseous decomposition products. (a) It is not necessary to add a sacrificial compound because water can be used as a sacrificial compound.

[0062] In addition, the activation strategy may include (2) an operating strategy that controls the activation process via a set of valves to introduce the one or more sacrificial compounds and / or flush out the reaction products, (3) providing at least one vent to release gases generated by the oxidation / reduction process, (4) adjusting, maintaining and controlling pH during the activation step to promote the oxidation / reduction reaction, (5) a capacity rebalancing strategy during the device life to compensate for electrode capacity drift, and / or (6) providing chemically delithiated electrodes during manufacturing before incorporating the electrodes into the battery pack or electrochemical water cleaning device described herein.

[0063] Desalination operation can begin when one or both electrodes are partially or completely filled with alkali metals. In this case, the working electrode has a pre-activation ion shuttle capacity of less than about 50%, 40%, 30%, 20%, 10%, or 5%, meaning that less than about 50%, 40%, 30%, 20%, 10%, or 5% of the host lattice is open to accept ions shuttled during the intercalation process, or the electrode retains ions at a state of charge (SOC) of less than about 50%, 40%, 30%, 20%, 10%, or 5%. Based on the total shuttle capacity of the working or host electrode, the post-activation shuttle capacity can be from about 50% to 100%, and can be about 50%, 60%, 70%, 80%, 90%, or 100%.

[0064] To initiate water desalination operation when one or both electrodes (i.e., the working electrode alone, or the working electrode and the counter electrode) are partially or completely filled with alkali metals, ion deintercalation is achieved by applying a voltage or current that causes ions to be removed from the host structure, such as NaMnO2. Since the host now has more open space to accept ions during the intercalation process, deintercalation results in an increase in the shuttle capacity of the host electrode.

[0065] To compensate for the removal of ions such as Na from the electrode + The positive charge generated in the working electrode compartment can introduce sacrificial compound A. This sacrificial compound is reduced in the counter electrode compartment. For each anion generated by sacrificial reduction, such as Cl... - Ions must pass through the AEM and balance the insertion and extraction of cations such as Na. + The process is schematically depicted in Figure 3 middle.

[0066] Figure 3 An example system with two symmetrical electrodes is shown, which can be, for example, a NaX:carbon:binder composite electrode, where X is the electrode active material. A specific example could be graphite plus NaMnO2:Super P:PVDF in a ratio of 80:10:10, where X is MnO2. The composition of the electrodes can vary, as they may contain other materials described herein.

[0067] It can be seen that, Figure 3 It is depicted that both embedded electrodes contain ions, namely NaX (0 < 0), at the start of device / system operation. x ≤1) Schematic activation process. By applying an action that causes NaX, such as Na, to precipitate from the host structure NaX, the activation process is described. x The voltage or current that removes ions from MnO2 causes deintercalation at the working electrode. This is to compensate for the removal of ions such as Na from the electrode. +The positive charge generated in the working electrode compartment is reduced by sacrificial compound A in the counter electrode compartment. For each anion produced by sacrificial reduction, Cl... - It is necessary to pass through the AEM and balance the insertion and extraction of ions such as Na + .

[0068] Compound A used for sacrificial reduction can be obtained via H2O + e at approximately ~0 V relative to SHE. - → OH - + ½H₂ reduces to H₂O. When the sacrificial compound is water, the goal is to intentionally use a voltage outside or within the water electrochemical window, indicating the range of voltages at which the substance is neither oxidized nor reduced. Typically, in the electrode, the voltage is kept within the water window because water is electrolyzed outside this range, resulting in a waste of electrical energy intended for another electrochemical reaction. The electrochemical window for pure water is 0 to 1.23 V. However, when water is used as the sacrificial compound described herein, voltages outside the stability window are intentionally used, such as below about 0 V, leading to the reduction of water and the generation of anions.

[0069] Instead of pure water, the sacrificial compound may include various soluble substances in salt or solution form, which can be added to the water. The soluble substances may be acids such as methanesulfonic acid (CH4O3S) reduced to -0.6V, butyric acid (CH3(CH2)2COOH) reduced to butyraldehyde at -0.3V, or combinations thereof.

[0070] Alternatively or additionally, the redox sacrificial compound or compound A used for sacrificial reduction can be a solid blended into the electrode slurry during electrode fabrication. Examples of solids include lithium salts or their sodium analogues, such as lithium bis(oxalato)borate (LiB(C₂O₄)₂) reduced at ~1V or sodium bis(oxalato)borate (NaB(C₂O₄)₂) reduced at ~1V. Lithium and sodium can be partially substituted by other alkali metals and alkaline earth metals, including K, Mg, Ca, etc., or combinations thereof.

[0071] The sacrificial compound A can have a higher reduction potential than the electrode potential in its fully or partially intercalated state. The sacrificial compound A is readily reduced at the working electrode potential. This is to compensate for the negative charge A. - The generation of positive ions such as Na+ from the working electrode + Intercalation and deintercalation occur, and the electrode potential changes accordingly. As a result, anions such as Cl... - Ions do not need to pass through AEM, because, as Figure 4 The diagram illustrates how this maintains charge neutrality.

[0072] The sacrificial compound A used for reduction can be one or more relatively small redox molecules added to the aqueous stream. Example compounds include those added via Q + 2H at an equilibrium voltage of 0.15 V relative to the SHE. + + 2e - → Quinones reduced by QH2, formic acid (HCOOH) reduced at ~0.1V, acetic acid (CH3COOH) reduced at ~0.03V, propionic acid (CH3CH2COOH) reduced at ~0.07V, butyric acid (CH3(CH2)2COOH) reduced to butanol at ~0.08V, or combinations thereof.

[0073] Desalination operation can be initiated when one or both electrodes (i.e., the working electrode alone, or the working electrode and the counter electrode) are partially or completely free of alkali metals. In this case, the working or host electrode has a pre-activation ion shuttle capacity greater than about 50%, meaning that greater than about 50%, 60%, 70%, 80%, 90%, or 100% of the host lattice is open to accept ions shuttling during intercalation, or the electrode retains ions at a state of charge (SOC) greater than about 50%, 60%, 70%, 80%, 90%, or 100%. Based on the total shuttle capacity of the electrodes, the post-activation shuttle capacity can be from about 0% to 50%, and the shuttle capacity can be about 5%, 10%, 20%, 30%, 40%, or 50%.

[0074] To initiate water desalination operation when both electrodes are partially or completely free of alkali metals, the working electrode is incorporated with ions from water by applying a voltage or current that causes ion intercalation into the host structure, such as an X:carbon:binder composite electrode (where X is the electrode active material). A non-limiting example of X could be FeFe(CN)6. To compensate for the removal of positive charges, such as Na, from the working electrode compartment... + The sacrificial compound A is oxidized in the counter electrode compartment. For each embedded Na... + Anions such as Cl - It is necessary to pass through AEM and balance the cations (A) generated by sacrificial oxidation. + The system is schematically depicted in... Figure 5 middle.

[0075] The redox sacrificial compound, or compound A used for sacrificial oxidation, can be obtained at approximately 1.0 V relative to SHE via the reaction 2H₂O → O₂ + 4H₂O. + + 4e - Oxidized H2O. The sacrificial oxidizing compound may be any soluble substance added to water. The soluble substance may be an organic compound such as ethylene glycol C2H6O2, which has an equilibrium voltage of about 0.5V relative to SHE.

[0076] The redox compound A used for sacrificial oxidation can be a solid that is blended into the electrode slurry during electrode manufacturing. The solid can be an inorganic or organic lithium compound or its sodium-modified analogues, such as lithium azide (LiN3) or its equivalent sodium azide (NaN3) with an equilibrium voltage of about 0.3V, lithium carbonate (Li2CO3) oxidized at ~1.3V, sodium carbonate (Na2CO3) oxidized at ~1.3V, carbonaceous compounds such as Li2C4O4 oxidized at ~0.7V, dicarboxylic acids such as Li2C3O5 oxidized at ~1.2V, Li2C4O6 oxidized at ~1.3V, Li2C2O4 oxidized at ~1.6V, and hydrazide [COCON(Li)] oxidized at ~0.1V. n etc., or combinations thereof.

[0077] The sacrificial compound A may have an oxidation potential lower than the electrode potential in the fully or partially deintercalated state. In such cases, the sacrificial compound A is readily oxidized at the working electrode potential. To compensate for the positive charge A... + The generation of this will result in positive ions from the solution, such as Na+. + It is embedded in the working electrode, and the electrode potential changes accordingly. Anions such as Cl... - Ions do not need to pass through AEM, because, as Figure 6 As illustrated in the diagram, it maintains charge neutrality.

[0078] The sacrificial compound A can be one or more small redox molecules added to the aqueous stream, such as via QH2 → Q + 2H at an equilibrium voltage of 0.15V relative to SHE. + + 2e - Oxidized hydroquinone. Other examples of sacrificial redox molecules are metallocenes (e.g., ferrocene), halogens (e.g., I₂), and others. - / I 3- ) and aromatic molecules (e.g., tetramethylphenylenediamine). Some non-limiting examples of specific materials within the above categories suitable for an equilibrium voltage of -0.1 to 1.5 V relative to SHE include ferrocene with an equilibrium voltage of 0.05 to 0.38 V, n-butylferrocene with an equilibrium voltage of 0.18 to 0.5 V, N,N-dimethylaminomethylferrocene with an equilibrium voltage of 0.13 to 0.68 V, 1,1-dimethylferrocene with an equilibrium voltage of 0.06 to 0.34 V, 1,2,4-triazole, sodium salt (NaTAZ) with an equilibrium voltage of 0.1 V, and lithium squarate with an equilibrium voltage of about 0.1 V.

[0079] The one or more sacrificial compounds can be gases, liquids, gels, or solids. If the compound is a gas or liquid, it can be metered into an aqueous stream for easy application. If the compound is a solid or gel, it can be included in the electrode slurry or added to an aqueous stream during manufacturing, as described above. At least some of the sacrificial compounds can be soluble. Some of the compounds can be insoluble.

[0080] The class of redox molecules used in the activation step can be selected based on the products formed during their sacrificial oxidation / reduction. For example, one or more redox molecules can be selected to create a protective or passivating layer on one or both electrodes to protect and / or stabilize the electrodes during subsequent battery pack operation. Alternatively, the redox molecules can form solid, liquid, or gaseous substances that are beneficial to the performance of the battery pack or electrochemical water desalination device disclosed herein.

[0081] The system may include one or more valves to introduce the gaseous, liquid, gel, or solid sacrificial compound from the aqueous stream into the battery pack, flush out reaction products from the system, or both. The device may include one or more inlet valves, one or more outlet valves, or a combination thereof. An activation strategy involving the valves may include the following steps: one or more soluble sacrificial compounds A may be added to a water reservoir, from which they are conveyed via pipes or inlet channels to an electrochemical water cleaning device. Once the sacrificial compound reaches the water cleaning device, at least one inlet and at least one outlet valve of the device may be closed to maintain a quiescent state within the device. In other words, no water flows while the sacrificial compound is present in the device.

[0082] The valve may be a two-way valve or a three-way valve. The valve allows for temporary cessation of water flow, reverse flow, emergency discharge of the system, rinsing, release of water from the system, or a combination thereof. The valve enables the system to temporarily become a closed system in which the activation process described herein can occur. The valve may be valve 126 as described above.

[0083] The concentration of the sacrificial compound A can be chosen such that the amount of sacrificial compound A in the device volume (the number of moles of one or more compounds A in water) under quiescent conditions corresponds to the amount of ion B to be inserted into or extracted from the electrode. If the sacrificial redox reaction proceeds as a single-electron reaction and the inserted ion is monovalent, then the molar numbers of A and B are the same, n A = n B Typically, the relationship should be z. B n A = z A n B , where z Aand z B These refer to the valences of the sacrificial compound A and the embedded ion B, respectively.

[0084] The activation process can be carried out, for example, in a closed system via a valve. Alternatively, the activation process can be carried out in a non-static mode, wherein the sacrificial compound(s) A and the reaction products are continuously flushed through an electrochemical water cleaning device. Activation can also be carried out in a partially or temporarily closed system. Some activation strategies described herein, such as rebalancing, can be carried out in a closed or open system after the battery pack has been in operation.

[0085] The system may also include one or more vents 132 capable of releasing gases generated by the oxidation / reduction process. The vents 132 may be resealable. The valve 126, the vents 132, or both may be manually operated or operated via the controller 130 described above.

[0086] Additionally, the system may include one or more additional reservoirs 123 connected to the battery pack 100 via pipes or channels, and one or more valves 126 supplying a medium during the activation step to adjust and / or control the pH of the system. For example, the medium may include one or more acids or one or more bases compatible with water treatment. Introducing a pH-adjusting medium can facilitate oxidation / reduction reactions and reduce the overpotential required to drive the reaction associated with the aforementioned added sacrificial compound A. The pH-adjusting medium may be introduced into the system as a single stream or multiple streams, such that each compartment has its own inlet for the pH-adjusting medium. The multi-stream configuration allows the medium to be introduced into only one compartment, while a second compartment may remain without or substantially without the medium. Alternatively, a second reservoir with a different medium and separate channels, valves, and / or inlets may be provided for the second compartment. The medium in the second reservoir and compartment may differ from the medium in the first reservoir and compartment. The first and second media may differ in chemical composition, concentration, temperature, additional chemical or physical properties, or combinations thereof.

[0087] The operation of the electrochemical water desalination system may also include reactivation or rebalancing strategies to balance the capacity during operation of the device, thereby compensating for electrode capacity drift. Figure 2(Aging conditions in the process). Typically, the shuttle capacity of one or both electrodes may decrease over time. If, for example, one of the electrodes still holds ions at 30% state of charge (SOC), while the other is fully charged, such as at 100% SOC, the device cannot operate at full capacity because only 70% of the total charge can move. To address this, parasitic reactions involving one or more sacrificial compounds, as described above, can be driven to deintercalate ions from one electrode without intercalating them into the other, and vice versa. The SOC balance between the electrodes can be reset or rebalanced to a desired value, such as 0% / 100% or 50% / 50%. Specifically, rebalancing can be achieved by metering one or more sacrificial compounds A into the aqueous stream, by driving the respective side reactions described above, by introducing one or more sacrificial compounds A into the electrode slurry during manufacturing (provided that at least some of the one or more sacrificial compounds A remain in the electrode body after initial activation and any previous rebalancing), or a combination thereof.

[0088] In addition to sacrificial compounds and activation strategies utilizing redox reactions, other activation strategies may include providing chemically delithiated electrodes during electrode manufacturing before incorporating them into the battery pack electrodes or electrochemical water cleaning devices described herein. For example, electrode manufacturing may include chemical steps including delithiation to ensure that one electrode is fully delithiated and has 100% shuttle capacity or position / space to accept intercalated ions during device operation. The second electrode may be fully lithiated or at approximately 0% shuttle capacity. Alternatively, both electrodes may be designed during manufacturing to have shuttle capacities of approximately 0 to 100%, such that both electrodes have approximately 50% shuttle capacity when the battery pack is assembled. Thus, delithiation becomes part of the manufacturing process, rather than the first step in battery pack operation.

[0089] Alternatively, a hybrid deionization (HDI) device having a capacitive electrode and an intercalation electrode can undergo the activation steps and techniques described above. The device may include a cation intercalation host electrode coupled to a carbon-based electrode on the other side to adsorb anions from water. The carbon-based electrode may comprise porous carbon, activated carbon, etc. The hybrid device can be "activated" by extracting cations from the intercalation host electrode, since the carbon-based counter electrode is naturally in a discharged state when the battery is first assembled. The same techniques described herein can be applied to this process.

[0090] In one or more embodiments, a method is provided for activating the battery pack or desalination device described herein. The method includes activating the electrodes of the battery pack. The method may include partially or completely filling one electrode with an alkali metal and completely or partially evacuating a second electrode of the alkali metal. Filling and evacuating may respectively result in a configuration where one electrode is at approximately 100% ion shuttle capacity and the second electrode is at approximately 0% shuttle capacity. Alternatively, the SOC balance may be different, such as approximately 50% / 50% as described above. The method may include increasing or decreasing the shuttle capacity of the electrodes through one or more processes described herein.

[0091] The method may include activating the electrode by providing one or more sacrificial compounds A into the battery pack system, as described above (a)-(e). The method may include using one or more sacrificial compounds A while applying a voltage. The method may include using pure water or water containing one or more dissolved solids as sacrificial compound A. The method may utilize oxidation and / or reduction reactions. The method may utilize one or more sacrificial compounds A having a reduction potential higher or lower than that of the electrode. The method may include adding one or more small redox molecules into the system.

[0092] The method may include providing one or more sacrificial compounds A into one or two compartments. The compartment into which one or more sacrificial compounds A may be added may be a compartment having an electrode that is partially or completely filled with an alkali metal, or is to be partially or completely filled with an alkali metal, such that the electrode has approximately 0% shuttle capacity. Alternatively, the compartment into which one or more sacrificial compounds A may be a compartment having an electrode that is partially or completely free of alkali metal, or is to be partially or completely free of alkali metal, such that the electrode has approximately 100% shuttle capacity.

[0093] The method may include providing one or more sacrificial compounds A into the system via an aqueous stream, one or more pipes, inlets, channels, one or more valves, or combinations thereof. The method may include providing one or more sacrificial compounds into the system via one or more streams, pipes, inlets, channels, valves, or combinations thereof. The method may include adding one or more sacrificial compounds A, which may be in the form of a gas, liquid, gel, solid, or a combination thereof, via one or more of the above-described pathways. The method may include introducing one or more sacrificial compounds A that are dissolved in, soluble in, or insoluble in the water of the battery pack system.

[0094] Alternatively, the method may include introducing one or more sacrificial compounds into an electrode slurry during manufacturing, such that the electrode already contains the sacrificial compound(s) when the system is constructed. The method may then include providing a potential to a working electrode that releases one or more sacrificial compounds A into the system to achieve desired or predetermined intercalation and / or deintercalation changes within the electrode.

[0095] The method may include, for example, removing oxidation-reduction reaction products from the battery pack system via one or more discharge ports, outlets, one or more valves, or combinations thereof. The method may also include leaving the reaction products in the system.

[0096] The method may include activating the system when the system is a closed system. Alternatively, the method may include activating the electrode when the system is an open system. The method may include continuously or discontinuously flushing the reaction products out of the battery pack.

[0097] The method may include adjusting the pH of the system by providing one or more pH-adjusting media, which are supplied to the system via one or more streams.

[0098] Alternatively, the method may include activating the battery pack by delithiating the electrodes during the manufacturing process so that the electrodes are manufactured to have a desired or predetermined capacity.

[0099] The method may include, as described above, operating the battery pack and, during said operation, reactivating or rebalancing one or two electrodes to achieve a desired or predetermined shuttle capacity.

[0100] The processes, methods, or algorithms disclosed herein can be transferred to, or implemented by, a processing device, controller, or computer, which may include any existing programmable electronic control unit or dedicated electronic control unit. Similarly, the processes, methods, or algorithms can be stored in many forms as data and instructions executable by a controller or computer, including but not limited to information permanently stored on non-writable storage media such as ROM devices and information reproducibly stored on writable storage media such as floppy disks, magnetic tapes, CDs, RAM devices, and other magnetic and optical media. The processes, methods, or algorithms can also be implemented in a software executable object. Alternatively, the processes, methods, or algorithms can be implemented, wholly or partially, using suitable hardware components such as application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), state machines, controllers, or other hardware components or devices, or a combination of hardware, software, and firmware components.

[0101] While exemplary embodiments have been described above, they are not intended to describe all possible forms included in the claims. The language used in this specification is descriptive and not restrictive, and it should be understood that various changes may be made without departing from the spirit and scope of this disclosure. As previously stated, features of various embodiments may be combined to form other embodiments that may not be explicitly described or shown. Although various embodiments may be described as offering advantages or superiority over other embodiments or prior art implementations in one or more desired characteristics, those skilled in the art will recognize that one or more features or characteristics can be compromised to achieve the desired overall system properties, depending on the specific application and implementation. These properties may include, but are not limited to, cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, suitability, weight, manufacturability, ease of assembly, etc. Therefore, any embodiment described as being less desirable than other embodiments or prior art implementations in one or more characteristics is not outside the scope of this disclosure and may be desirable for a particular application.

Claims

1. A desalination battery pack, comprising: The working embedded electrode in the first compartment; The second compartment contains the embedded electrode, and both compartments contain a saline aqueous solution with an increased concentration of dissolved salts; An ion exchange membrane disposed between the compartments; and The sacrificial compound for sacrificial oxidation or for sacrificial reduction is configured to neutralize the charge in the first compartment at a predetermined voltage and be consumed simultaneously by an oxidation or reduction reaction when the working intercalation electrode is activated prior to operation of the battery pack. The sacrificial compound does not contain water and comprises one or more water-soluble redox molecules. and One or more valves, by closing the valves, make the desalination battery pack a closed system, so that no water flows when the sacrificial compound is present in the battery pack.

2. The desalination battery pack according to claim 1, further comprising at least one discharge port configured to release activation reaction products.

3. The desalination battery pack of claim 1, further comprising one or more valves configured to bring the sacrificial compound into the first compartment.

4. The desalination battery pack according to claim 1, wherein, prior to activation, one of the electrodes comprises an alkali metal such that the alkali metal-containing electrode retains ions in a state of charge of less than 50% prior to activation.

5. The desalted battery pack according to claim 1, wherein the sacrificial compound has a higher reduction potential than the working intercalation electrode potential in a partially or fully intercalated state.

6. The desalination battery pack according to claim 1, further comprising a protective layer formed on the working intercalation electrode, the counter-intercalation electrode, or both, for stabilizing the electrodes during battery pack operation.

7. A method for activating the working embedded electrode of a desalted battery pack, the method comprising: A desalted battery pack is provided, the desalted battery pack comprising: The working embedded electrode and the counter-embedded electrode, each electrode arranged in a separate compartment containing a saline aqueous solution with an elevated concentration of dissolved salts; and An ion exchange membrane disposed between the compartments; Before the battery pack is operational, A predetermined voltage is provided to the working insertion electrode to (a) deintercalate ions from the electrode into the compartment, thereby increasing the ion shuttle capacity of the electrode, or (b) insert ions from the compartment into the electrode, thereby decreasing the ion shuttle capacity of the electrode; and The sacrificial compound used for sacrificial reduction or the sacrificial compound used for sacrificial oxidation is reduced to neutralize the charge in one of the compartments at a predetermined voltage when the working intercalation electrode is activated before the battery pack is put into operation, and the sacrificial compound is consumed by the oxidation or reduction reaction. The sacrificial compound does not contain water and includes one or more water-soluble redox molecules.

8. The method of claim 7, further comprising releasing one or more activated reaction products via at least one discharge port.

9. The method of claim 7, further comprising delivering the sacrificial compound to the compartment via at least one valve.

10. The method of claim 7, further comprising increasing the ion shuttle capacity from 50% or less of the pre-activation capacity to 100%.

11. The method of claim 7, further comprising adjusting the pH in the compartment by adding a pH adjusting medium to at least one of the compartments.

12. The method of claim 7, further comprising forming a protective layer on the working embedded electrode and / or on the embedded electrode to stabilize the electrode for battery pack operation.

13. A method for activating a desalted battery pack having electrodes, the method comprising: An electrode configuration achieving 100% / 0% state of charge balance through the ion shuttle capacity of the rebalancing electrodes, wherein each electrode is arranged in a separate compartment containing a saline aqueous solution, which is achieved by applying a predetermined voltage to the electrodes to release ions from one or more of the electrodes into the solution or to attract ions from the solution to one or more of the electrodes, and providing at least one sacrificial compound for sacrificial reduction to be reduced upon activation of the working intercalation electrode before the battery pack is operated, or at least one sacrificial compound for sacrificial oxidation to be oxidized upon activation of the working intercalation electrode before the battery pack is operated and simultaneously neutralizing the charge generated by the applied voltage, wherein the sacrificial compound does not contain water and comprises one or more water-soluble redox molecules.

14. The method of claim 13, wherein the sacrificial compound comprises one or more dissolved redox molecules.

15. The method of claim 13, further comprising releasing the activated reaction product via at least one vent, and delivering the at least one sacrificial compound to the compartment via at least one valve, or both.

16. The method of claim 13, wherein the at least one sacrificial compound has a reduction potential higher than the working embedding electrode potential in a partially or fully embedded state.

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