Rechargeable ion battery with polyaniline cathode and lean electrolyte

Abstract

A unique framework for rocking chair type sodium-ion and potassium-ion batteries is disclosed. In the case of a sodium-ion battery, the battery includes a first electrode assembled operably as the anode of the battery and containing a source of sodium ions. The battery includes a second electrode assembled operably as the cathode of the battery and containing at least one polymer binder, a conductive carbon-based material, and an active material. The battery further includes an electrolyte positioned between the first and second electrodes and supporting the electrochemical transport of sodium ions. The active material includes a binary composite, the binary composite includes a polyaniline polymer and a graphene-based material. The first electrode, the second electrode, and the electrolyte are assembled operably to function as a rocking chair type sodium-ion battery.

Description

[Technical Field]

[0001] Reference to related applications This application claims priority and benefit of U.S. Provisional Patent Application No. 63 / 452,748, “SODIUM BATTERIES WITH POLYANILINE BASED CATHOD AND LEAN ELECTROLYTE,” filed with the U.S. Patent and Trademark Office on 17 March 2023, the contents of which are incorporated herein by reference as if they were fully described herein.

[0002] This disclosure relates to a rechargeable metal-ion battery, and more particularly to a rechargeable metal-ion battery that utilizes a composite of polyaniline and a graphene-based material as the active component of the battery cathode. [Background technology]

[0003] Rechargeable batteries are a type of secondary battery that can be recharged and used multiple times, making them an environmentally friendly and cost-effective alternative to disposable batteries. They are widely used in portable electronic devices such as smartphones, laptop computers, and cameras, as well as in larger applications such as electric vehicles and energy storage systems. The most common types of rechargeable batteries are nickel-cadmium batteries, nickel-metal hydride batteries, and lithium-ion batteries. Each type of rechargeable battery has its own unique characteristics, including energy density, voltage, and discharge rate, which make them suitable for various applications. Rechargeable batteries must be properly maintained, including being stored correctly, charged correctly, and used within the operating temperature range, to ensure their performance and lifespan. Lightweight rechargeable batteries with high energy capacity are a target of exploration in autonomous energy science.

[0004] A typical metal-ion battery contains an anode, a cathode, and an electrolyte that separates the anode and cathode. The electrolyte is usually a liquid or solid containing metal ions and acts as a charge carrier between the anode and cathode. When the battery is charged, these ions move from the cathode to the anode through the electrolyte, and when the battery is discharged, they move in the opposite direction.

[0005] The separator in a battery containing a liquid electrolyte acts as a barrier between the anode and cathode, preventing electrical short circuits while allowing the flow of metal ions. Separators are typically porous materials, usually made of polypropylene immersed in the electrolyte. This allows ions to flow while maintaining the battery's structure. The separator plays a crucial role in maintaining the battery's stability and safety, ensuring its smooth and efficient operation.

[0006] Lithium-ion batteries are widely used in various portable electronic devices such as mobile phones, cameras, audio equipment, and laptop computers, as well as in electric vehicles, hybrid vehicles, and autonomous power sources for power grid systems.

[0007] Sodium-ion batteries were developed as an alternative to lithium-ion batteries. The development of sodium-ion batteries was motivated by the fact that sodium precursors for batteries are very readily available and inexpensive.

[0008] The active material of the anode in sodium-ion batteries typically includes sodium metal, or sodium alloys of Sn, Sb, Bi, Si, Ge, Si, or P; hard or soft carbon materials; graphene-containing materials; transition metal compounds; or composites based thereon. (I. Hasa et al., Challenges of today for Na-based batteries of the future: From materials to cell metrics. J. Power Sources, 2021, Vol. 482, 228872.)

[0009] Liquid electrolytes typically consist of a solution of sodium salts, a mixture of salts in an aprotic organic solvent, or a mixture of aprotic organic solvents. These liquid electrolytes are usually present in the pores of both the anode and cathode, separated by a separator such as a porous polypropylene membrane. The amount and concentration of the liquid electrolyte play a crucial role in providing both minimum battery weight and maximum ionic conductivity.

[0010] The electrochemical active material of the cathode in a sodium-ion battery is, for example, one of the most important factors determining the overall energy storage capacity of the device. Cathode active materials typically include layered sodium oxide, polyanionic compounds, and inorganic transition metal-containing cathode materials such as Prussian blue analogs, which are currently considered promising for sodium-ion battery applications (Yu. Huang et al., "Electrode Materials of Sodium-Ion Batteries toward Practical Application," ACS Energy Lett., 2018, Vol.3, p. 1604; I. Hasa et al., Challenges of today for Na-based batteries of the future: From materials to cell metrics. J. Power Sources, 2021, Vol.482, 228872; Quan Pei et al., "Improving the Na 0.67 Ni 0.33 Mn 0.67O2Cathode Material for High-Voltage Cyclability via Ti / Cu Codoping for Sodium-Ion Batteries”, ACS Appl. Energy Mater., 2022, Vol. 5, p. 1953; S. Wang et al., “Carbon-Modified NASICON Na4FeV(PO4)3Cathode with Enhanced Kinetics for High-Performance Sodium-Ion Batteries”, ACS Appl.Energy Mater.,2022,Vol.5,9616 pages; W. Hua et al., "Preparation method and application of Prussian blue analogue cathode material", China Patent Application No. CN115207316A (2022); S. Xu et al., "Promising Cathode Materials for Sodium-Ion Batteries from Lab to Application", ACS Cent.Sci., 2023, Vol. 9, 2012 pages; L. Wang et al., “Research Progress and Modification Measures of Anode and Cathode Materials for Sodium-Ion Batteries”, ChemElectroChem, 2024, Vol. 11, e202300414.).

[0011] However, achieving a specific capacity exceeding 150 mAh / g using known materials is rare, and furthermore, harmful decomposition reactions using known materials have been shown to affect the structure and composition of the materials, limiting the potential of high-energy sodium-ion batteries (G. Brugnetti et al., The Role of Surface Coating in P'2-Na 0.67 Mn 0.67 Ni 0.33O2: Enhancing Capacity and Stability of Layered Cathodes for Sodium-ion Batteries. Batteries&Supercaps, 2023, e202300332.)。

[0012] In addition, layered Zr-doped Na x Li y M z O a oxide (where M = Ni, Mn or Co) has been shown to be able to have a sufficiently high specific capacity of about 230 mAh / g in the potential range of 1.5 to 4.3 V with respect to Na + / Na, but the presence of Co in the composition brings more significant cost and environmental problems (K.Y. Chung et al., "Cathode active material for sodium-ion battery, and preparation process thereof", US Patent Application No. US2021075053A1 (2021).).

[0013] Manganese-based layered cathodes achieved a higher specific capacity of approximately 286 mAh / g due to their anionic redox activity. However, a somewhat low mid-potential of approximately 2.5V and insufficient cyclability reduced the likelihood of using this material in sodium-ion batteries (specific capacity decreased to approximately 240 mAh / g after 5 cycles) (G. Shaohua et al., "Manganese based layered positive electrode material for high-specific-energy sodium-ion battery, and preparation method and application of manganese-based layered positive electrode material", Chinese Patent Application No. CN115117336A (2022); Qi Wang et al., "Dual Honeycomb-Superlattice Enables Double-High Activity and Reversibility of Anion Redox for Sodium-Ion Battery Layered Cathodes", Angew. Chem., 2022, Vol.134, e202206625).

[0014] Some organic materials have been used as substitutes for inorganic cathode materials (X. Yin et al., "Recent Progress in Advanced Organic Electrode Materials for Sodium-Ion Batteries: Synthesis, Mechanisms, Challenges and Perspectives," Adv.Funct.Mater., 2020, Vol.30, 1908445; R. Rajagopalan et al., "Understanding the sodium storage mechanisms of organic electrodes in sodium ion batteries: Issues and Solutions," Energy Environ.Sci., 2020, Vol.13, p. 1568). A characteristic feature of these organic materials is the presence of carbon-containing groups and heteroatom-containing groups that enable reversible electrochemical conversion. The specific capacity of these materials is rarely higher than 150 mAh / g when their discharge potential is sufficiently high, while the discharge capacity of these materials can be somewhat higher when their discharge potential is sufficiently low. Therefore, high-energy sodium-ion batteries utilizing organic cathode materials remain an unresolved challenge in the research and development of rechargeable batteries. Furthermore, in some cases, the electrochemical action of organic materials involves the insertion / extraction of anions present in the battery electrolyte, making organic materials suitable only for dual-ion batteries.

[0015] For example, polybenzothiazole-based cathode materials are Na +It can exhibit a specific capacity of approximately 150 mAh / g in the potential range of 1.5 to 4.0 V relative to Na. (W. Gang et al., "Sulfonated polybenzothiazole-based cathode material for sodium-ion battery and preparation method of sulfonated polybenzothiazole-based cathode material", Chinese Patent Application No. CN114975999A (2022).) In another example, a ladder-type hexaazatriphenylene polymer is Na + With respect to Na, in the potential range of 0.9 to 3.5V, a specific capacitance of 170 to 180 mAh / g was observed with a discharge current of 100 mA / g, but the intermediate potential was Na + It is only about 2V relative to Na. (RRKapaev et al., "Conjugated Ladder-Type Polymer with Hexaazatriphenylene Units as a Cathode Material for Lithium, Sodium, and Potassium Batteries", ACS Appl. Energy Mater., 2021, Vol. 4, pp. 10423.) Furthermore, modified pyrene polymers are Na + It showed a specific capacitance of approximately 360 mAh / g in the potential range of 1.0 to 3.5V relative to Na, but the intermediate potential was also Na + It has a voltage of approximately 2V relative to Na, and because the polymer content in the cathode material is relatively low, it does not support the manufacture of high-energy batteries based on it (R. Shi et al., "In Situ Polymerized Conjugated Poly(pyrene-4,5,9,10-tetraone) / Carbon Nanotubes Composites for High-Performance Cathode of Sodium Batteries", Adv. Energy Mater., 2021, Vol.11, 2002917).

[0016] The organic polymer polyaniline has been used alone as an active ingredient in sodium battery cathodes. Due to its conjugated bonding system, polyaniline is redox active, can become electrically conductive through doping, and can undergo reverse electrochemical transformation at high potentials. These properties motivate the use of polyaniline as an active ingredient in sodium ion battery cathodes. For example, self-doped polyaniline has been used as a component in sodium ion battery cathodes with a reversible specific capacity of approximately 100 mAh / g at a specific discharge current of 50 mA / g (YFShen et al., "Poly(diphenylaminesulfonic acid sodium) as a cation-exchange organic cathode for sodium batteries", Electrochem.Commun., 2014, Vol.49, p.5). In another study, self-doped polyaniline showed a capacity of approximately 133 mAh / g and exhibited high cycle performance (M. Zhou et al., A sulfonated polyaniline with high density and high rate Na-storage performances as a flexible organic cathode for sodium-ion batteries. Chem.Commun., 2015, 51, 14354~14356). Polyaniline hollow nanofibers were used as a cathode material for sodium-ion batteries and showed a reversible capacity of 153 mAh / g (H. Han et al., Polyaniline hollow nanofibers prepared by controllable sacrifice template route as high-performance cathode materials for sodium-ion batteries. Electrochim.Acta 2019, Vol.301, 352~358).Finally, hybrid nanocomposites based on transition metal hexacyanoferrates and polyaniline demonstrated a specific discharge capacity of up to 150 mAh / g in sodium-ion battery cathodes (Q. Zhang et al., "Surface engineering induced core-shell Prussian blue@polyaniline nanocubes as a high-rate and long-life sodium-ion battery cathode", J. Power Sources, 2018, Vol. 395, p. 305).

[0017] However, the specific capacity of polyaniline, which is equivalent to or below the typical 50% doping limit (approximately 150 mAh / g), is relatively low for a high-efficiency cathode in sodium batteries that should be manufactured. + The electrochemical activity of self-doped polyaniline at potentials above 1.7V relative to sodium is thought to be due to the insertion / extraction of sodium cations, while the electrochemical activity of general polyaniline (undoped) in the aforementioned potential range is thought to be due to the insertion / extraction of anions present in the electrolyte. Therefore, polyaniline polymers are practically applicable only as cathodes in double-ion batteries (M. Zhou et al., A sulfonated polyaniline with high density and high rate Na-storage performances as a flexible organic cathode for sodium ion batteries. Chem.Commun., 2015, 51, 14354~14356; H. Han et al., Polyaniline hollow nanofibers prepared by controllable sacrifice-template route as high-performance cathode materials for sodium-ion batteries. Electrochim. Acta 2019, Vol.301, 352~358).

[0018] Recently, a specific capacity of approximately 175 mAh / g corresponding to polyaniline doping exceeding 50% limit has been demonstrated in lithium-ion batteries (J. Gaubicher et al., "Lithium-Doped Pernigraniline-Based Materials", International Patent Application No. PCT / EP2015 / 053689). The composite of polyaniline and graphene-based materials has shown a rather large specific capacity of approximately 250 mAh / g (O. Posudiievskyi, International Patent Application No. PCT / IB2018 / 055009). However, it should be noted that there is no evidence of practical high specific capacity and long-term charge / discharge cycles of polyaniline in sodium-ion batteries.

[0019] The minimum amount of anions required for 100% doping of polyaniline is considered to be 1 anion per nitrogen atom of the polymer, or 1 mole of anions per approximately 91 grams of the polymer (C6H4NH is usually regarded as the unit cell of polyaniline), or equal to 1 L of a commonly used liquid organic electrolyte having an alkali metal salt concentration of 1 M per approximately 91 grams of the polymer (Y. Yamada et al., "Advances and issues in developing salt concentrated battery electrolytes", Nat. Energy, 2019, Vol. 4, p. 269; Z. Guo et al., "Toward Full Utilization and Stable Cycling of Polyaniline Cathode for Nonaqueous Rechargeable Batteries", Adv. Energy Mater., 2023, Vol. 13, 2301520).

[0020] Therefore, theoretically, approximately 11 mL of electrolyte is required per gram of polymer in the cathode material, or approximately 15 grams of electrolyte per charge of 294 mAh, which is the theoretical charge storage limit of the polymer. Consequently, the ratio of electrolyte weight to cathode capacity (E / C) in such batteries is approximately 50 g / (Ah). This extremely high E / C value suggests a severe limitation, if not a practical disadvantage, for double-ion batteries with polyaniline cathodes. In fact, practical lithium-ion batteries exhibit an E / C ratio of less than 3 g / (Ah) (X. Ren et al., "Enabling High-Voltage Lithium-Metal Batteries under Practical Conditions", Joule, 2019, Vol.3, p. 1662; Sh. Chen et al., "Critical Parameters for Evaluating Coin Cells and Pouch Cells of Rechargeable Li-Metal Batteries", Joule, 2019, Vol.3, p. 1094; J. Liu et al., "Pathways for practical high-energy long-cycling lithium metal batteries", Nat. Energy, 2019, Vol.4, p. 180; H. Li., "Practical Evaluation of Li-Ion Batteries", Joule, 2019, Vol.3, p. 911).

[0021] Potassium-ion batteries were developed as an alternative to lithium-ion batteries. The development of potassium-ion batteries was facilitated by the fact that potassium precursors for batteries are more readily available and less expensive than lithium, and that potassium has a lower oxidation-reduction potential than sodium. + and Na + Compared to ions, K +Motivated by the much smaller Stokes radius of ions, the applicability of aluminum foil instead of copper foil as the current collector of the anode, and the applicability of graphite as the active anode material (K. Sada et al., "Challenges and Prospects of Sodium-Ion and Potassium-Ion Batteries for Mass Production", Adv. Energy Mater., 2023, Vol. 13, 2302321; Yan-Song Xu et al., "High-Performance Cathode Materials for Potassium-Ion Batteries: Structural Design and Electrochemical Properties", Adv. Mater. 2021, Vol. 33, 2100409.).

Prior Art Documents

Patent Documents

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Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Non-Patent Documents

[0023]

Non-Patent Document 1

[0024] In general, systems and methods are disclosed that provide a novel mechanism for the charging / discharging process of polyaniline, without the involvement of anions and based on the reversible insertion / extraction of cations, particularly sodium and potassium cations. The systems and methods of this disclosure solve the problem of the large amount of electrolyte conventionally considered necessary to allow polyaniline to function as an electrochemically active component in the cathodes of rechargeable metal-ion batteries, particularly sodium-ion and potassium-ion batteries, while providing long-term reversible charge / discharge cycles for polyaniline. This approach has many positive implications for cathodes of practical rechargeable sodium-ion and potassium-ion batteries.

[0025] This disclosure presents a novel battery model that utilizes sodium as a mobile cation, but it should be understood that other embodiments are equally possible in which the cation is a different species, such as potassium, though not limited to this model.

[0026] The systems and methods disclosed herein demonstrate the potential for rocking chair-like functionality in fixed electrolyte batteries utilizing polyaniline as the cathode active component. A practical advantage of a constant electrolyte concentration is that the metal ion conductivity between the electrodes of the battery is maximized to fill the electrode pores, resulting in highly efficient metal ion transport. A minimum amount of electrolyte sufficient to fill the separator and electrode pores provides an E / C ratio of less than 7 g / (Ah), comparable to the most well-known commercially available lithium-ion batteries.

[0027] In a first general embodiment, a sodium-ion battery includes a first electrode assembled to function as the anode of the battery, providing a source of sodium ions; a second electrode assembled to function as the cathode of the battery, comprising at least one polymer binder, a conductive carbon-based material, and an active material; and an electrolyte positioned between the first and second electrodes to support the electrochemical transport of sodium ions. The active material comprises a binary composite comprising 1) a polyaniline polymer and 2) a graphene-based material. The first electrode, the second electrode, and the electrolyte are assembled to function as a rocking chair type sodium-ion battery.

[0028] In one embodiment, the battery further includes an insulating porous separator positioned between the first and second electrodes. In this embodiment, the electrolyte is a liquid electrolyte comprising at least one aprotic solvent and at least one sodium salt soluble in at least one aprotic solvent. Alternatively, the liquid electrolyte comprises at least one ionic liquid, the at least one ionic liquid comprising at least one sodium salt soluble in at least one ionic liquid. In this embodiment, the insulating porous separator is immersed in the electrolyte, and the amount of electrolyte in the battery, expressed as the ratio of electrolyte weight to cathode capacity, is less than 7 g / (Ah).

[0029] In one embodiment, the electrolyte of the battery is a sodium ion-conducting solid. The solid includes a sodium ion-conducting organic polymer; a sodium ion-conducting inorganic compound; a sodium ion-conducting ionogel; or a composite material comprising a sodium ion-conducting organic polymer, a sodium ion-conducting inorganic compound, a sodium ion-conducting ionogel, or a combination thereof.

[0030] In a second general embodiment, the potassium-ion battery includes a first electrode assembled to function as the anode of the battery, providing a source of potassium ions; a second electrode assembled to function as the cathode of the battery, comprising at least one polymer binder, a conductive carbon-based material, and an active material; and an electrolyte positioned between the first and second electrodes to support the electrochemical transport of potassium ions. The active material comprises a binary composite comprising a polyaniline polymer and a graphene-based material. The first electrode, the second electrode, and the electrolyte are assembled to function as a rocking chair type potassium-ion battery.

[0031] In one embodiment of the second general embodiment, the battery further includes an insulating porous separator positioned between the first and second electrodes. In this embodiment, the electrolyte is a liquid electrolyte comprising at least one aprotic solvent and at least one ionic liquid comprising at least one potassium salt soluble in at least one aprotic solvent and at least one potassium salt soluble in at least one ionic liquid. The insulating porous separator is immersed in the electrolyte. The amount of electrolyte in the battery, expressed as the ratio of electrolyte weight to cathode capacity, is less than 7 g / (Ah).

[0032] In another embodiment of the second general aspect, the electrolyte of the battery is a potassium ion-conducting solid and comprises a potassium ion-conducting organic polymer, a potassium ion-conducting inorganic compound, a potassium ion-conducting ionogel, or a composite material comprising a potassium ion-conducting organic polymer, a potassium ion-conducting inorganic compound, a potassium ion-conducting ionogel, or a combination thereof.

[0033] In a third general embodiment, a method for fabricating a metal-ion battery is provided. This method includes the steps of preparing a first electrode containing a source of metal ions and assembling the first electrode so that it can function as the anode of a battery, and preparing a second electrode and assembling the second electrode so that it can function as the cathode of a battery. The second electrode comprises at least one polymer binder, a conductive carbon-based material and an active material. This method further includes the step of placing an electrolyte between the first and second electrodes to support the electrochemical transport of metal ions between the first and second electrodes. The active material comprises a binary composite comprising polyaniline and graphene-based materials.

[0034] In one embodiment of the third general aspect, the metal is sodium or potassium.

[0035] In one embodiment of the third general aspect, a binary composite of polyaniline and graphene-based material is prepared by a process comprising grinding a mixture of polyaniline as an emeraldine base and the graphene-based material. In the relevant embodiment, the grinding is carried out in a solvent-free environment. In another relevant embodiment, the graphene-based material comprises a mixture of multilayer, single-layer, and monolayer graphene particles. In yet another relevant embodiment, the mixture is prepared by chemical, mechanochemical, electrochemical, acoustic, or thermochemical exfoliation of particles of graphite, graphene oxide, graphite intercalation compounds, or expanded graphite. The mixture of polyaniline as an emeraldine base and the graphene-based material can be prepared using a relative weight ratio of polyaniline:graphene-based material between about 75:25 and about 99:1. This method may include an optional step of isolating and purifying the polyaniline-graphene-based material composite.

[0036] In another embodiment of the third general aspect, the second electrode is formed by a deposition step comprising depositing a cathode material onto a current collector, the cathode material comprising a binder, a conductive additive, and an active material. In the relevant embodiment, the binder is water-soluble. Furthermore, the deposition step may include preparing a slurry of the cathode material by mixing the binder, the conductive additive, and the active material with water. The binder may be soluble in a polar organic solvent. In the relevant embodiment, the deposition step includes preparing a slurry of the cathode material by mixing the binder, the conductive additive, and the active material with a polar organic solvent. In the relevant embodiment, this method includes using a slurry that does not contain N-methylpyrrolidone.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art. In carrying out or testing any of the described embodiments, similar or equivalent methods and materials may be used, but preferred methods and materials are described below. Furthermore, materials, methods, and examples are illustrative and not restrictive. In the event of any conflict with terms used in the art, this specification, including definitions, shall prevail.

[0038] The above summary is illustrative and not intended to be limiting. In addition to the exemplary aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description and claims.

[0039] This embodiment is described with reference to the figures in the attached drawings, which may not necessarily be to scale, and similar references indicate similar elements. [Brief explanation of the drawing]

[0040] [Figure 1] This figure shows a cross-section of a rechargeable battery using a polyaniline-based cathode according to one embodiment. [Figure 2]This figure shows a chart plotting specific capacity versus cycle count for the first and second battery cells described herein. [Figure 3] This figure shows a chart plotting specific capacity versus cycle count for the third battery cell described herein. [Figure 4] The third cell is shown in a chart plotting potential versus discharge capacity. [Figure 5] The following is a chart plotting specific capacity versus cycle count for the fourth battery cell according to this disclosure. [Figure 6] This figure shows a chart plotting specific capacity versus cycle count for the fifth battery cell according to this disclosure. [Modes for carrying out the invention]

[0041] Figure 1 is an exemplary cross-sectional view of a rechargeable battery 1 according to one embodiment. In this embodiment, the active components of the battery cathode are 1) polyaniline; and 2) a binary composite of graphene-based materials. In this embodiment, the rechargeable battery 1 includes an anode layer 2, an electrolyte layer 3, and a cathode layer 4. In this embodiment, the anode layer 2 is composed of, but is not limited to, sodium or a sodium alloy, a sodium-containing composite, or other anode material. Alternatively, the anode layer 2 may be composed of, but is not limited to, a material such as a hard carbon material, a graphene material, a transition metal compound, or any combination thereof as the active component. It should be understood that to obtain optimal battery performance, sodiumized forms of hard carbon, graphene, or transition metal-based materials can be used.

[0042] In this embodiment, the electrolyte layer 3 may be: 1) a porous polymer membrane immersed in a liquid electrolyte which is a sodium salt solution or a solution of multiple sodium salts in an organic aprotic solvent or a mixture of different aprotic solvents, preferably a sodium salt solution containing additives that help improve the electrode-electrolyte interface; 2) a porous separator immersed in an ionic liquid electrolyte which is a sodium salt solution or a solution of multiple sodium salts in an ionic liquid or a mixture of different ionic liquids; 3) a sodium ion-conducting solid electrolyte layer which includes an organic polymer membrane capable of conducting sodium ions, either alone or in combination with the corresponding sodium salt; 4) a sodium ion-conducting inorganic solid; 5) a composite thereof; or 6) a solid ionogel electrolyte.

[0043] In this embodiment, the cathode layer 4 contains a binary composite of 1) polyaniline and 2) a graphene-based material as an active ingredient, hereinafter referred to as "PANI / GBM," which is disclosed in International Patent Application No. PCT / IB2018 / 055009, the entirety of which is incorporated herein by reference. The PANI / GBM composite can be prepared by a solvent-free mechochemical process, which involves the mechochemical treatment of a mixture of polyaniline as an emeraldine base and multilayer, minority-layer, and monolayer graphene particles as GBM. The mechochemical procedure for preparing the PANI / GBM composite is similar to the mechochemical procedure for preparing hybrid nanocomposites disclosed in O. Posudievsky et al., "Hybrid Two-and Three-Component Host-Guest Nanocomposites and Method for Manufacturing the Same" and U.S. Patent Application No. 12 / 623,000 to GM Global Technology Operations, Inc., the latter the entirety of which is incorporated herein by reference.

[0044] In this embodiment, it was shown that the rechargeable battery 1 exhibits a rocking chair function (i.e., an inductive charge / discharge cycle of sodium cation insertion / extraction) by utilizing a sodium metal anode, an electrolyte layer, and a PANI / GBM composite cathode. The rechargeable battery 1 was assembled in a Swagelok cell in an argon-filled MBRAUN glove box with an oxygen and water content of less than 0.1 ppm.

[0045] The properties of rechargeable battery 1 were investigated, and several cells were fabricated. The first cell, "Cell I," contained a cathode material formed from a mechanochemically prepared PANI / GBM composite with a polyaniline to GBM weight ratio of approximately 9:1, a polymer binder, and a carbon black additive, according to the procedure specified in International Patent Application No. PCT / IB2018 / 055009. International Patent Application No. PCT / IB2018 / 055009 is incorporated herein by reference. The weight ratio of the cathode material components was 85:10:5 (PANI / GBM composite:polymer binder:carbon black additive). In this example, the polymer binder was poly[(vinylidene fluoride)-co-hexafluoropropylene] copolymer, and acetone was used as the solvent for preparing the slurry to deposit the PANI / GBM composite cathode material onto the cathode current collector using a doctor blade. The loading of the cathode material was approximately 2 mAh / cm². 2 The design was carried out to ensure a single-sided area capacity. To demonstrate a rocking chair function (e.g., cation insertion / extraction induction charge / discharge cycle), cell I utilized an electrolyte layer consisting of a Celgard 2400 polypropylene membrane (Celgard, LLC, Charlotte, North Carolina, United States) immersed in a mixture of ethylene carbonate-diethyl carbonate (50:50 volume ratio) containing an anode made from a bulky piece of sodium metal, 5.5 mg of cathode material, and 0.42 mg of NaClO4 salt sufficient to ensure that the doping degree of polyaniline present in the cathode material was exactly 10%.

[0046] The second cell, "Cell II," was fabricated using a procedure similar to that of Cell I, except that pure polyaniline was used as the emeraldine base instead of the PANI / GBM complex used in Cell I as the active material for the cathode.

[0047] The third cell, "Cell III," was prepared using a procedure similar to that of Cell I, except that the separator was immersed in a 1M NaClO4 solution in an ethylene carbonate-diethyl carbonate mixture (volume ratio 50:50).

[0048] The fourth cell, "Cell IV," was prepared using a procedure similar to that of Cell III, except that polyvinylidene fluoride binder and N-methyl-2-pyrrolidone (NMP) were used as solvents during the preparation of the slurry for depositing the PANI / GBM-based cathode material onto the cathode current collector.

[0049] The fifth cell, "Cell V," was prepared using a procedure similar to that of Cell III, except that the polymer binder was a 1:3 mixture of polyolefin-grafted acrylic acid copolymer (3 wt% aqueous solution) and carboxymethylcellulose (2.5 wt% aqueous solution). In this example, redistilled water was used to prepare a cathode material slurry to be deposited onto the cathode current collector using a doctor blade. The cathode material was dried in air at 60°C, followed by drying under vacuum at 80°C.

[0050] In all cases, the specific volume was calculated using the polyaniline content in the cathode material. + The tests were performed with respect to Na at a potential range of 1.7–4.1V. Both the charging and discharging currents were equal to 15mA / g. The specific current value was calculated using the total weight of the cathode material.

[0051] Referring to Figure 2, the cycle data shows an increase in the discharge specific capacity of polyaniline in cell I. Figure 2 shows the ability of polyaniline to maintain charge / discharge cycles even without a sufficient number of mobile anions in the electrolyte (1 / 10 of the amount theoretically required for 100% doping), reaching approximately 60% of its theoretical specific capacity of 294 mAh / g by the 5th cycle. This means that the capacity of polyaniline in that cycle was about 6 times higher than the maximum theoretical value available for anion doping of polyaniline, due to the particularly limited sodium salt content in the electrolyte of cell I. Although we do not wish to be constrained by theory, it is assumed that the steady increase in polyaniline specific capacity is due to the progressive sodiumization of nitrogen atoms in its structure. This is because the doping / dedoping of polyaniline in cell I during the cycle could only proceed to this extent with the involvement of mobile sodium cations.

[0052] Figure 2 further shows that the efficient function of polyaniline as the active component of the cathode in cell I is due to the presence of GBM and its effect on polyaniline, because in the absence of GBM particles (and therefore the absence of interaction between GBM particles and polyaniline polymers), the specific volume of polyaniline in cell II, which does not contain GBM in the composition of the cathode material, reaches only about 1 / 23 of its maximum theoretical doping level, that is, due to the amount of mobile anions in the electrolyte of cell II, it falls more than twice below the theoretical limit of 10%.

[0053] Referring to Figure 3, the charge-discharge cycle data for cell III is shown. The polyaniline in cell III is characterized by a high specific capacity of approximately 260 mAh / g. Furthermore, Figure 4 shows that the PANI / GBM composite in cell III is Na +It is shown to be characterized by a high intermediate potential of approximately 3.04V relative to / Na. In one optional embodiment, it is thought that dissolving a small amount of sodium salt as an electrolyte component in an organic aprotic solvent can simultaneously ensure a low battery weight and provide the required level of ionic conductivity. These data demonstrate that polyaniline-based sodium-ion batteries with a lean electrolyte and a weight / capacity ratio of less than 5 g / (Ah) can function similarly to known commercially available lithium-ion batteries.

[0054] Referring to Figure 5, the charge-discharge cycle data for cell IV is shown. From this data, it is clear that N-methylpyrrolidone partially dissolves polyaniline, and therefore, using a binder such as polyvinylidene fluoride together with a solvent such as N-methylpyrrolidone should be avoided (contraindicated) when preparing the PANI / GBM cathode material slurry and depositing the cathode material onto the cathode current collector during the manufacture of cell IV. The dissolution of polyaniline disrupts the interaction between polyaniline and GBM, in turn eliminating the progression of a new doping mechanism for polyaniline and limiting its specific capacity in cell IV to the value of 50% doping.

[0055] Referring to Figure 6, charge-discharge cycle data for cell V is shown. Figure 6 shows that aqueous solutions of water-soluble binders such as polyacrylic acid and carboxymethylcellulose can be used to prepare the cathode material slurry, which can reduce the cost of preparing and processing the cathode material and reduce the use of organic solvents, which pose ecological and environmental hazards associated with battery manufacturing.

[0056] Electrochemically active organic electrode materials are characterized by ion universality. In related similar embodiments, a rocking chair potassium-ion battery can be manufactured using a PANI / GBM composite as the cathode active material. Importantly, in certain organic solvents, K + / K potential is Na + / Na potential and further Li + Potassium ions can be lower than the Li potential, which is useful for increasing energy density. Similar to sodium-ion batteries, potassium ions do not form alloys with aluminum when aluminum foil is used as the anode current collector. In contrast to sodium ions, potassium ions can intercalate into graphite at high capacity. Compared to lithium and sodium ions, potassium ions exhibit considerably weaker Lewis acidity and a smaller Stokes radius in organic solvents, thereby showing increased ionic mobility across the bulk electrolyte and electrolyte / electrode interface, which is advantageous for achieving high power density.

[0057] Potassium ions have a larger radius (1.38 Å) than sodium ions (1.02 Å). Therefore, using conventional inorganic electrode materials in potassium-ion batteries can cause significant structural deformation, potentially leading to lower capacity and rapid capacity degradation. In contrast, organic electrode materials assembled by specific van der Waals forces often have large interlayer spacings and flexible structures.

[0058] However, the average voltage of potassium-ion batteries with cathodes based on electrochemically active materials is generally below 3V, and the capacity of these materials rarely exceeds 150mAh / g. (X. Zhu et al., Recent Advances in Polymers for Potassium Ion Batteries. Polymers, 2022, 14, 5538; M. Wang et al., Organic Electrode Materials for Non-aqueous K-Ion Batteries. Trans. Tianjin University, 2021, Vol.27, 1~23; S. Liu et al., Challenges and Strategies toward Cathode Materials for Rechargeable Potassium-Ion Batteries. Adv. Mater. 2021, Vol.33, 2004689; Lin Li et al., Cathode materials for high-performance potassium-ion batteries. Cell Reports Physical Science 2, 100657.)

[0059] In particular, we have shown that polyaniline can be used as an electrochemical active material in the cathode of a potassium-ion battery. However, while the average voltage of the battery was approximately 3V, the capacity of polyaniline was less than 150mAh / g. In addition, the electrochemical action of polyaniline in this case was due to anion insertion / extraction, and the battery in this disclosure was a double-ion potassium battery. (H. Gao et al., A High-Energy-Density Potassium Battery with a Polymer-Gel Electrolyte and a Polyaniline Cathode. Angew. Chem. Int. Ed. 2018, Vol. 57, 5449~5453.)

[0060] Several exemplary embodiments have been described. However, it will be understood that various modifications can be made without departing from the spirit and scope of the various embodiments presented herein. Accordingly, other embodiments are included in the following claims.

Claims

1. It is a sodium-ion battery, A first electrode assembled to function as the anode of the battery, including a sodium ion source; Assembled to function as the cathode of the aforementioned battery, the second electrode comprises at least one polymer binder, a conductive carbon-based material, and an active material; An electrolyte and are positioned between the first and second electrodes to support the electrochemical transport of sodium ions. Includes, The active material comprises a binary composite including 1) a polyaniline polymer and 2) a graphene-based material; and The first electrode, the second electrode, and the electrolyte are assembled to function as a rocking chair type sodium-ion battery. Sodium-ion battery.

2. The present invention further includes an insulating porous separator disposed between the first and second electrodes; The aforementioned electrolyte is At least one aprotic solvent, and at least one sodium salt soluble in the at least one aprotic solvent; or, A minimum ionic liquid containing at least one sodium salt soluble in at least one ionic liquid. It is a liquid electrolyte containing; The insulating porous separator is immersed in the electrolyte; and The amount of electrolyte in the battery, expressed as the ratio of electrolyte weight to cathode capacity, is less than 7 g / (Ah). The sodium-ion battery according to claim 1.

3. The aforementioned electrolyte, Sodium ion conductive organic polymer; Sodium ion conductive inorganic compounds; Sodium ion-conducting ionogel; or Composite materials comprising the sodium ion-conducting organic polymer, the sodium ion-conducting inorganic compound, the sodium ion-conducting ionogel, or a combination thereof A sodium-ion battery according to claim 1, comprising a sodium-ion conductive solid.

4. It is a potassium-ion battery, A first electrode assembled to function as the anode of the battery, including a potassium ion source; Assembled to function as the cathode of the aforementioned battery, the second electrode comprises at least one polymer binder, a conductive carbon-based material, and an active material; An electrolyte and are positioned between the first and second electrodes to support the electrochemical transport of potassium ions. Includes, The active material comprises a binary composite including 1) a polyaniline polymer and 2) a graphene-based material; and The first electrode, the second electrode, and the electrolyte are assembled to function as a rocking chair type potassium-ion battery. Potassium ion battery.

5. The present invention further includes an insulating porous separator disposed between the first and second electrodes; The aforementioned electrolyte is At least one aprotic solvent, and at least one potassium salt soluble in the at least one aprotic solvent; The at least one ionic liquid contains at least one potassium salt soluble in at least one ionic liquid. It is a liquid electrolyte containing; The insulating porous separator is immersed in the electrolyte; and The amount of electrolyte in the battery, expressed as the ratio of electrolyte weight to cathode capacity, is less than 7 g / (Ah). The potassium-ion battery according to claim 4.

6. The aforementioned electrolyte, Potassium ion conductive organic polymer; Potassium ion conductive inorganic compounds; Potassium ion conductive ionogel; or Composite materials comprising the aforementioned potassium ion conductive organic polymer, the aforementioned potassium ion conductive inorganic compound, the aforementioned potassium ion conductive ionogel, or a combination thereof It is a potassium ion conductive solid containing The potassium-ion battery according to claim 4.

7. A method for manufacturing a metal ion battery, The steps include: preparing a first electrode containing a source of metal ions, and assembling the first electrode so that it can function as the anode of the battery; The steps include: preparing a second electrode and assembling the second electrode so that it can function as the cathode of the battery, wherein the second electrode comprises at least one polymer binder, a conductive carbon-based material, and an active material; The steps include placing an electrolyte between the first electrode and the second electrode to support the electrochemical transport of metal ions, Includes, The active material includes a binary composite containing polyaniline and graphene-based materials. method.

8. The method according to claim 7, wherein the metal is sodium or potassium.

9. The method according to claim 7, wherein the binary composite of polyaniline and graphene-based material is prepared by a process comprising grinding a mixture of polyaniline as an emeraldine base and graphene-based material.

10. The method according to claim 9, wherein the grinding is carried out in a solvent-free environment.

11. The method according to claim 9, wherein the graphene-based material comprises a mixture of multilayer, few-layer, and single-layer graphene particles.

12. The method according to claim 11, wherein the mixture is prepared by chemical, mechanochemical, electrochemical, acoustic, or thermochemical exfoliation of particles of graphite, graphene oxide, graphite intercalation compound, or expanded graphite.

13. The method according to claim 9, wherein the mixture of polyaniline as an emeraldine base and a graphene-based material is prepared using a relative weight ratio of polyaniline to graphene-based material between about 75:25 and about 99:

1.

14. The method according to claim 9, further comprising an optional step of separating and purifying the composite of polyaniline and graphene-based material.

15. The method according to claim 7, wherein the second electrode is formed by a deposition step including depositing a cathode material on a current collector, the cathode material comprising a binder, a conductive additive, and the active material.

16. The method according to claim 15, wherein the binder is water-soluble.

17. The method according to claim 16, wherein the deposition step includes preparing a slurry of the cathode material by mixing the binder, the conductive additive and the active material with water.

18. The method according to claim 15, wherein the binder is soluble in a polar organic solvent.

19. The method according to claim 18, wherein the deposition step comprises preparing a slurry of the cathode material by mixing the binder, the conductive additive and the active material with a polar organic solvent.

20. The method according to claim 19, wherein the slurry does not contain N-methylpyrrolidone.

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