Patent Grant
9745202
1. Field of the Invention
This invention generally relates to electrochemical cells and, more particularly, to a method for synthesizing metal cyanometallates (MCMs) for use in battery electrodes.
2. Description of the Related Art
Large-capacity, cost-effective energy storage is the transformational technology needed to enable the large scale integration of renewable energy (e.g. wind, solar). The rechargeable battery offers efficient electrical energy storage (EES). The lithium (Li)-ion battery has been the leading option based on its performance, but it is too expensive for large-scale EES. Therefore, it is necessary to develop superior low cost, high-performance electrode materials to reduce the cost of lithium-ion batteries or to develop a new system of rechargeable metal-ion batteries to replace lithium-ion batteries.
Sodium and potassium-ion batteries have attracted a great deal of attention recently because the reserves of sodium/potassium are more plentiful than lithium in the crust of earth. This abundance makes it possible to develop low cost batteries for EES. However, it is impractical to copy the structures of lithium-ion (Li+)-host compounds for use as sodium-ion (Na+) or potassium-ion (K+)-host compounds. Sodium and potassium ions are much larger than lithium ions and severely distort the structures of the Li+-host compounds. Thus, it is very important that new Na+/K+-host materials be developed, with a large interstitial space into which sodium/potassium-ions can easily and reversibly move. Na+/K+-ions have been inserted into metal cyanide compounds. Transition metal hexacyanoferrates (TMHCFs) with large interstitial space have been investigated as cathode materials for rechargeable lithium-ion batteries [1,2], sodium-ion batteries [3,4], and potassium-ion batteries [5]. With an aqueous electrolyte containing the proper alkali-ions or ammonium-ions, copper and nickel hexacyanoferrates [(Cu,Ni)-HCFs] demonstrated robust cycling life with 83% capacity retention after 40,000 cycles at a charge/discharge current of 17 C (1 C=150 milliamp hours per gram (mAh/g) [6-8]. In spite of this, the materials demonstrated low capacities and energy densities because: (1) only one sodium-ion can be inserted/extracted reversibly into/from Cu-HCF or Ni-HCF per formula unit, and (2) these TM-HCFs electrodes must be operated below 1.23 V due to the water electrochemical window. The electrochemical window of a substance is the voltage range between which the substance is neither oxidized nor reduced. This range is important for the efficiency of an electrode, and once out of this range, water becomes electrolyzed, spoiling the electrical energy intended for another electrochemical reaction.
In order to compensate for these shortcomings, manganese hexacyanoferrate (Mn-HCF) and iron hexacyanoferrate (Fe-HCF) were used as cathode materials in non-aqueous electrolyte [9, 10]. When assembled with a sodium-metal anode, Mn-HCF and Fe-HCF electrodes cycled between 2.0V and 4.2 V delivered capacities of ˜110 mAh/g. Very recently, FeFe(CN)6.4H2O and Na0.61Fe[Fe(CN)6]0.94 were reported to exhibit high energy density and power density and good stability during cycling [11, 12].
The MCM capacity is determined by the available A-sites in the compounds into which the alkali or alkaline ions can be inserted reversibly in the range of working voltages. From the electric neutrality point of view, the valences of M1 and M2 mainly contribute to the amount of the available A-sites. For example, 2 sodium-ions can be inserted/extracted into/from Na2MnFe(CN)6 between 2-4 V vs. Na° because the valences of Mn- and Fe-ions can change between +2 and +3, and its theoretical capacity is 171 mAh/g. Noteworthy is the fact that a greater number of metal-ions, “A”, result in MCMs able to deliver a higher capacity for use in a metal-ion battery with a non-metal counter electrode. In addition, in order to neutralize charges, the transition metals are kept at low valances. In typical MCM materials (AXM1NM2M(CN)Z.dH2O) the value of
It would be advantageous if a synthesis process existed to increase the number of “A” metal-ions in MCM materials.
Disclosed herein are methods for synthesizing metal cyanometallates (MCMs) with the general formula ANM1PM2Q(CN)R such that the value of
In one aspect, the materials are synthesized with a solution containing M1a2(CN)z2b−-ions and materials containing M2. Generally, a high concentration of “A”-ions is included in the solution. An acid is added into the synthesis solution to decompose the M2-containing materials to form M2-ions that interact with M1a2(CN)z2b−-ions to form a framework. The synthesis may be carried out at a controlled temperature from 0 Centigrade (C.) to 100° C. in an inert atmosphere such as nitrogen and/or argon. To neutralize charges, “A”-ions occupy the interstitial positions of the framework. A precipitation is formed that can be vacuum dried at a temperature in the range of 0° C. to 200° C.
Accordingly, a first method is provided for synthesizing metal cyanometallate, (MCM). The method provides a solution of AXM1Y(CN)Z;
where “A” is selected from a first group of metals;
where M1 is selected from a second group of metals;
where
where
where
The method adds a material including M2 to the solution to form a liquid phase material that may be either a suspension or a solution. M2 is selected from the second group of metals. The material may be pure M2 and it may be an oxide, sulfide, sulfite, carbonate, cyanide, or fluoride compound. The method adds acid to the liquid phase material. The addition of acid to the liquid phase material decomposes the M2 material into M2-ions. In one aspect, the method additionally adds a reducing agent to the liquid phase material. Simultaneous with the addition of the acid, a precipitate of ANM1PM2Q(CN)R
where
where
where
where
where
Additional details of the above-described first method, as well as a second method, are presented below.
Disclosed herein are methods for the synthesis of metal cyanometallates (MCMs) or ANM1PM2Q(CN)R
In general, the precipitation method is used to synthesize MCM materials as electrodes. However, noteworthy is the fact that metal-ions with low valence are susceptible to being oxidized, resulting in low-“A” containing MCM. The “A” deficiency causes a low capacity when MCM is used as an electrode in a rechargeable “A”-ion battery with a counter electrode without “A”-ions. For example, Prussian white, Na2FeFe(CN)6 is expected to be synthesized with ferrous ions and ferrocyanide. But, the fact is that only Prussian blue, NaxFeFe(CN)6 (x<1), can conventionally be obtained because ferrous ions are easily oxidized.
To clarify the process, two examples are given here.
Method 1:
0.7 grams (g) iron (Fe) powder was mixed with 100 milliliters (mL) 0.02 moles (mol) L−1 Na4Fe(CN)4.10H2O solution to form a suspension. As used herein, a suspension is understood to be a heterogeneous mixture containing solid particles that are sufficiently large for sedimentation. The internal phase (solid) is dispersed throughout the external phase (fluid) through mechanical agitation, with the use of certain excipients or suspending agents. Generally, without agitation, the solid particles will eventually settle. A solution is a homogeneous mixture composed of only one phase. In such a mixture, a solute is a substance dissolved in another substance, known as a solvent. The solvent does the dissolving. The solution more or less takes on the characteristics of the solvent including its phase, and the solvent is commonly the major fraction of the mixture. The concentration of a solute in a solution is a measure of how much of that solute is dissolved in the solvent.
Continuing the description of the method, 10 mL 0.1 mol L−1 hydrogen chloride (HCl) solution was added into the suspension and stirred at room temperature. The Fe was decomposed by the to form Fe2+, which reacted with ferrocynide immediately to form Na2FeFe(CN)2. The obtained precipitate was collected by centrifuge or filtration, washed by water, and dried at 0-200° C. in a vacuum oven for 6-20 hours.
Method 2:
In a typical synthesis, 2 millimoles (mmol) Na4Fe(CN)4.10H2O and 0.1 mL HCl (37%) was dissolved in 500 mL of distilled water to obtain a homogenous solution. The solution was maintained at 0-100° C. for 0.5-60 hours being vigorous stirred to obtain Na2FeFe(CN)6. In the reaction, Fe2+-ions result from the decomposition of ferrocynide by HCl. The precipitate was collected by filtration in air, washed by water, and dried at 0-200° C. in a vacuum over for 0.5-60 hours.
Step 602 provides a solution of AXM1Y(CN)Z;
where “A” is selected from a first group of metals;
where M1 is selected from a second group of metals;
where
where
where
Some examples from the first group of metals include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), calcium (Ca), strontium (Sr), barium (Ba), silver (Ag), aluminum (Al), magnesium (Mg), and combinations thereof.
Step 604 adds a material including M2 to the solution to form a liquid phase material that is either a suspension or a solution. M2 is selected from the second group of metals. The M2 material may be pure M2 or a compound of oxides, sulfides, sulfites, carbonates, cyanides, fluorides, or a combination of these compounds. M1 and M2 are each independently selected from the second group of metals, some examples of which include titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), niobium (Nb), ruthenium (Ru), tin (Sn), indium (In), cadmium (Cd), Ca, Mg, strontium (Sr), and barium (Ba). Note: the materials listed above are examples used to illustrate the invention and do not necessarily represent an exhaustive list of all possible materials.
Step 606 adds an acid to the liquid phase material. Some examples of acids include hydrochloric acid (HCl), sulfuric acid (H2SO4), sulfurous acid (H2SO3), acetic acid (CH3COOH), formic acid (CHOOH), oxalic acid (C2H2O4), and ascorbic acid. In one aspect, adding the acid to the liquid phase material in Step 606 includes the acid decomposing the M2 material into M2-ions.
Optionally, adding the acid to the liquid phase material in Step 606 may additionally include adding a reducing agent to the liquid phase material. Some examples of reducing agents include sodium borohydride, sodium hyposulfite, sodium sulfite, and polyvinylpyrrolidon. In one aspect, adding the acid to the liquid phase material includes adding the acid to the liquid phase material in an inert atmosphere. For example, the process may be performed in an atmosphere of argon or nitrogen.
Simultaneously with the addition of the acid in Step 606, Step 608 forms a precipitate of ANM1PM2Q(CN)R
where
where
where
where
where
In one aspect, Step 610 dries the precipitate in a vacuum environment at a temperature in the range between 0 and 200 degrees C.
where “A” is selected from a first group of metals;
where M1 is selected from a second group of metals;
where
where
where
As mentioned above in the description of
Step 704 adds an acid to the solution. In one aspect, Step 704 includes the following substeps. In step 704a the acid decomposes the AXM1Y(CN)Z. Step 704b releases M1-ions into the solution. Some examples of acids include HCl, H2SO4, H2SO3, CH3COOH, CHOOH, C2H2O4, and ascorbic acid. In one aspect, Step 704 optionally includes adding a reducing agent to the solution, in addition to the acid. Some examples of reducing agents include sodium borohydride, sodium hyposulfite, sodium sulfite, and polyvinylpyrrolidon. In another aspect, the acid is added to the solution in an inert atmosphere. Note: the materials listed above are examples used to illustrate the invention and do not necessarily represent an exhaustive list of all possible materials.
Simultaneously with the addition of the acid in Step 704, Step 706 forms a precipitate of ANM1D(CN)E
where
where
where
where
In one aspect, Step 708 dries the precipitate in a vacuum environment at a temperature in the range between 0 and 200 degrees C.
Processes for the synthesis of MCM have been provided. Examples of particular materials and process details have been presented to illustrate the invention. However, the invention is not limited to merely these examples. Other variations and embodiments of the invention will occur to those skilled in the art.
The application claims the benefit of a Provisional application entitled, METAL CYANOMETALLATE SYNTHESIS METHOD, invented by Jie Song et al, Ser. No. 62/008,869, filed Jun. 6, 2014. This application is a Continuation-in-Part of an application entitled, RECHARGEABLE METAL-ION BATTERY WITH NON-AQUEOUS HYBRID ION ELECTROLYTE, invented by Long Wang et al, Ser. No. 14/271,498, filed May 7, 2014; which is a Continuation-in-Part of an application entitled, REACTIVE SEPARATOR FOR A METAL-ION BATTERY, invented by Long Wang et al, Ser. No. 14/230,882, filed Mar. 31, 2014; which is a Continuation-in-Part of an application entitled, NASICON-POLYMER ELECTROLYTE STRUCTURE, invented by Long Wang et al, Ser. No. 14/198,755, filed Mar. 6, 2014; which is a Continuation-in-Part of an application entitled, BATTERY WITH AN ANODE PRELOADED WITH CONSUMABLE METALS, invented by Yuhao Lu et al, Ser. No. 14/198,702, filed Mar. 6, 2014; which is a Continuation-in-Part of an application entitled, BATTERY ANODE WITH PRELOADED METALS, invented by Long Wang et al, Ser. No. 14/198,663, filed Mar. 6, 2014; which is a Continuation-in-Part of an application entitled, METAL BATTERY ELECTRODE WITH PYROLYZED COATING, invented by Yuhao Lu et al, Ser. No. 14/193,782, filed Feb. 28, 2014; which is a Continuation-in-Part of an application entitled, METAL HEXACYANOMETALLATE ELECTRODE WITH SHIELD STRUCTURE, invented by Yuhao Lu et al, Ser. No. 14/193,501, filed Feb. 28, 2014; which is a Continuation-in-Part of an application entitled, CYANOMETALLATE CATHODE BATTERY AND METHOD FOR FABRICATION, invented by Yuhao Lu et al, Ser. No. 14/174,171, filed Feb. 6, 2014; This application is a Continuation-in-Part of an application entitled, SODIUM IRON(II)-HEXACYANOFERRATE(II) BATTERY ELECTRODE AND SYNTHESIS METHOD, invented by Yuhao Lu et al, Ser. No. 14/067,038, filed Oct. 30, 2013; which is a Continuation-in-Part of an application entitled, TRANSITION METAL HEXACYANOMETALLATE-CONDUCTIVE POLYMER COMPOSITE, invented by Sean Vail et al., Ser. No. 14/059,599, filed Oct. 22, 2013; which is a Continuation-in-Part of an application entitled, METAL-DOPED TRANSITION METAL HEXACYANOFERRATE (TMHCF) BATTERY ELECTRODE, invented by Yuhao Lu et al., Ser. No. 13/907,892, filed Jun. 1, 2013, now U.S. Pat. No. 8,968,925, issued on Mar. 3, 2015; which is a Continuation-in-Part of an application entitled, HEXACYANOFERRATE BATTERY ELECTRODE MODIFIED WITH FERROCYANIDES OR FERRICYANIDES, invented by Yuhao Lu et al., Ser. No. 13/897,492, filed May 20, 2013; which is a Continuation-in-Part of an application entitled, PROTECTED TRANSITION METAL HEXACYANOFERRATE BATTERY ELECTRODE, invented by Yuhao Lu et al., Ser. No. 13/872,673, filed Apr. 29, 2013; which is a Continuation-in-Part of an application entitled, TRANSITION METAL HEXACYANOFERRATE BATTERY CATHODE WITH SINGLE PLATEAU CHARGE/DISCHARGE CURVE, invented by Yuhao Lu et al., Ser. No. 13/752,930, filed Jan. 29, 2013; which is a Continuation-in-Part of an application entitled, SUPERCAPACITOR WITH HEXACYANOMETALLATE CATHODE, ACTIVATED CARBON ANODE, AND AQUEOUS ELECTROLYTE, invented by Yuhao Lu et al., Ser. No. 13/603,322, filed Sep. 4, 2012. Ser. No. 13/752,930 is also a Continuation-in-Part of an application entitled, IMPROVEMENT OF ELECTRON TRANSPORT IN HEXACYANOMETALLATE ELECTRODE FOR ELECTROCHEMICAL APPLICATIONS, invented by Yuhao Lu et al., Ser. No. 13/523,694, filed Jun. 14, 2012, now U.S. Pat. No. 8,957,796, issued on Feb. 17, 2015; which is a Continuation-in-Part of an application entitled, ALKALI AND ALKALINE-EARTH ION BATTERIES WITH HEXACYANOMETALLATE CATHODE AND NON-METAL ANODE, invented by Yuhao Lu et al., Ser. No. 13/449,195, filed Apr. 17, 2012; which is a Continuation-in-Part of an application entitled, ELECTRODE FORMING PROCESS FOR METAL-ION BATTERY WITH HEXACYANOMETALLATE ELECTRODE, invented by Yuhao Lu et al., Ser. No. 13/432,993, filed Mar. 28, 2012. All these applications are incorporated herein by reference.
This invention was made with Government support under DE-AR0000297 awarded by DOE. The Government has certain rights in this invention.
| Number | Name | Date | Kind |
|---|---|---|---|
| 20050274225 | Bocarsly | Dec 2005 | A1 |
| Number | Date | Country |
|---|---|---|
| CN101041123 | Sep 2007 | CN |
| Entry |
|---|
| V. D. Neff, “Some Performance Characteristics of a Prussian Blue Battery”, Journal of Electrochemical Society 1985, 132, 1382-1384. |
| N. Imanishi et al., “Lithium Intercalation Behavior into Iron Cyanide Complex as Positive Electrode of Lithium Secondary Battery”, Journal of Power Sources 1999, 79, 215-219. |
| Y. Lu, L. Wang, J. Cheng, and J. B. Goodenough, “Prussian Blue: a New Framework for Sodium Batteries”, Chemistry Communications 2012, 48, 6544-6546. |
| L. Wang et al., “A Superior Low-Cost Cathode for a Na-ion Battery”, Angewandte Chemie International Edition 2013, 52, 1964-1967. |
| A. Eftekhari, “Potassium Secondary Cell Based on Prussian Blue Cathode”, Journal of Power Sources 2004, 126, 221-228. |
| C. D. Wessells et al., “Copper Hexacyanoferrate Battery Electrodes with Long Cycle Life and High Power”, Nature Communications 2011, 2, Article No. 550. |
| C. D. Wessells et al., “Nickel Hexacyanoferrate Nanoparticle Electrodes for Aqueous Sodium and Potassium Ion Batteries”, Nano Letters 2011, 11, 5421-5425. |
| C. D. Wesells et al., “The Effect of Insertion Species on Nanostrucured Open Framework . . . ”, Journal of the Electrochemical Society 2012, 159, A98-A103. |
| T. Matsuda, M. Takachi, and Y. Moritomo, “A Sodium Manganese Ferrocyanide Thin Film for Na-ion Batteries”, Chemical Communications 2013, 49, 2750-2752. |
| S-H. Yu et al., “Iron Hexacyanoferrate Nanoparticles as Cathode Materials for Lithium and Sodium Rechargeable Batteries”, ECS Electrochemistry Letters 2013, 2, A39-A41. |
| M. Hu and J. S. Jiang, “Facile Synthesis of Air-Stable Prussian White Microcubes via a Hydrothermal Method”, Materials Research Bulletin 2011, 46, 702-707. |
| S-H. Lee and Y-D. Huh, “Preferential Evolution of Prussian Blue's Morphology from Cube to Hexapod”, The Bulletin of the Korean Chemical Society 2012, 33, 1078-1080. |
| M. Hu, J-S. Jiang, C-C. Lin and Y. Zeng, “Prussian Blue Mesocrystals: an Emaple of Self-Construction”, CrystEngComm 2010, 12, 2679-2683. |
| M. Hu, R-P. Ji, and J-S. Jiang, “Hydrothermal Synthesis of Magnetite Crystals: from Sheet to Pseudo-Octahedron”, Materials Research Bulletin 2010, 45, 1811-1715. |
| X. Wu et al., Single-crystal FeFe(CN)6 nanoparticles: a high capacity and high rate cathode for Na-ion batteries, J. Mater. Chem. A., 1(2013)10130-10134. |
| Y.-G. Guo et al., “High-quality Prussian blue crystals as superior cathode materials for room-temperature . . . ”, Energy & Environmental Science, (2014) DOI: 10.1039/C3EE44004D. |
| Number | Date | Country | |
|---|---|---|---|
| 20150266746 A1 | Sep 2015 | US |
| Number | Date | Country | |
|---|---|---|---|
| 62008869 | Jun 2014 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14271498 | May 2014 | US |
| Child | 14731607 | US | |
| Parent | 14230882 | Mar 2014 | US |
| Child | 14271498 | US | |
| Parent | 14198755 | Mar 2014 | US |
| Child | 14230882 | US | |
| Parent | 14198702 | Mar 2014 | US |
| Child | 14198755 | US | |
| Parent | 14198663 | Mar 2014 | US |
| Child | 14198702 | US | |
| Parent | 14193782 | Feb 2014 | US |
| Child | 14198663 | US | |
| Parent | 14193501 | Feb 2014 | US |
| Child | 14193782 | US | |
| Parent | 14174171 | Feb 2014 | US |
| Child | 14193501 | US | |
| Parent | 14067038 | Oct 2013 | US |
| Child | 14174171 | US | |
| Parent | 14059599 | Oct 2013 | US |
| Child | 14067038 | US | |
| Parent | 13907892 | Jun 2013 | US |
| Child | 14059599 | US | |
| Parent | 13897492 | May 2013 | US |
| Child | 13907892 | US | |
| Parent | 13872673 | Apr 2013 | US |
| Child | 13897492 | US | |
| Parent | 13752930 | Jan 2013 | US |
| Child | 13872673 | US | |
| Parent | 13603322 | Sep 2012 | US |
| Child | 13752930 | US | |
| Parent | 13523694 | Jun 2012 | US |
| Child | 13603322 | US | |
| Parent | 13499195 | Apr 2012 | US |
| Child | 13523694 | US | |
| Parent | 13432993 | Mar 2012 | US |
| Child | 13499195 | US |
