An organic system ammonium ion battery and a preparation method thereof

Abstract

This invention discloses an organic ammonium ion battery, realizing a novel organic non-metallic ion energy storage system. This invention synthesizes a series of ammonium ion-rich (NH4) batteries. + Prussian white material (NH4) x Ni y Mn 1‑y HCF, where x = 0.5–1.911, y = 0–1.0, with the optimal values ​​being x = 1.911 and y = 0.019. This invention synthesizes a class of organic ammonium ion electrolytes for the first time by dissolving bis(trifluoromethanesulfonyl)imide ammonium (NH4TFSI) in an organic solvent. The Prussian white material prepared by this invention exhibits excellent ammonium storage performance. Using the above Prussian white material as the positive electrode and an aromatic compound as the negative electrode, organic ammonium ion batteries (OAIBs) are assembled. OAIBs exhibit excellent NH4 storage performance. + High performance and a wide electrochemical window (0–2.4 V). OAIBs also offer advantages such as low cost, high safety, and no pollution.

Description

[0001] The present application claims priority to Chinese patent application 2022104360528, filed on April 24, 2022, the contents of the specification, the drawings and the claims of which are incorporated herein by reference in their entirety and are part of the original written description of the present application. The applicant further declares that the applicant has the right to modify the specification and claims of the present application based on the priority document. TECHNICAL FIELD

[0002] The battery of the present application belongs to the technical field of energy storage, and specifically relates to a novel organic ammonium ion battery and a preparation method of a positive electrode material thereof. BACKGROUND

[0003] In today's era, the living standards and scientific and technological development of human beings are rapidly developing, accompanied by the rapid consumption of fossil fuels and the massive emission of CO2, causing a series of ecological and environmental problems, such as greenhouse effect, desertification, etc. The successful commercialization of lithium ion batteries has made people realize that electrochemical energy storage is an excellent choice to solve this problem. However, existing commercial batteries are mostly based on metal cations as charge carriers, and the distribution of alkali metal resources is uneven around the world. With the large-scale application of alkali metal ion batteries, the resources of alkali metals are gradually depleted, which will inevitably lead to the increase of battery cost and the overexploitation of metal minerals.

[0004] Therefore, the development of non-metallic ion batteries with abundant content in the earth's crust is an ideal solution to meet the requirements of sustainable development. Ammonium ion batteries, as a new type of non-metallic ion battery, were first proposed by the Cui Yi group of Stanford University in 2012. Since then, the research on ammonium ion batteries has been stagnant. Until 2017, the first "rocking chair" aqueous ammonium ion battery was formally reported by the Xiu Lei team of Oregon State University.

[0005] However, so far, all the research on ammonium ion batteries is based on aqueous solution as electrolyte, but the aqueous electrolyte is inevitably limited by hydrogen evolution and oxygen evolution reactions, which leads to low voltage and low energy density of ammonium ion batteries, thus seriously limiting the commercialization of ammonium ion batteries. Therefore, seeking an organic system of ammonium ion battery is an effective method to solve this problem. SUMMARY

[0006] To solve the above technical problems, the present application provides a preparation method of an organic ammonium ion battery with excellent cycle performance and high safety. The organic ammonium ion battery uses a type of Prussian white material rich in NH4 + as the positive electrode; PTCDI as the negative electrode; and a type of organic ammonium ion solution as the electrolyte.

[0007] To achieve the above purpose, the technical scheme of the present application is as follows:

[0008] A preparation method of a new ammonium ion battery, comprising the following steps:

[0009] (1) A preparation method of a positive electrode material of an ammonium ion battery, a NH4 + rich Prussian white material, with a general chemical formula of (NH4) x Ni y Mn 1-y [Fe(CN)6], (x = 0.5-1.911, y = 0-1). First, a precursor Na x Ni y Mn 1-y [Fe(CN)6] is prepared by a coprecipitation method, denoted as Na x Ni y Mn 1-y HCF. The Na x Ni y Mn 1-y HCF is mixed with an ammonium sulfate solution to perform ion exchange to obtain the target material.

[0010] (2) A preparation of an organic ammonium ion electrolyte. Ammonium bis(trifluoromethanesulfonyl)imide powder is dissolved in a mixed solution of ethylene carbonate and diethyl carbonate with a volume ratio of 1:1 or a tetraethylene glycol dimethyl ether organic solvent, heated and stirred to prepare electrolytes with concentrations of 0.5 mol / L, 1 mol / L, 2 mol / L, 2.5 mol / L, 3 mol / L, 4 mol / L and 5 mol / L.

[0011] (3) A preparation method of a counter electrode active material. Commercial activated carbon material is soaked in an appropriate amount of hydrofluoric acid, washed with water and ethanol three times respectively, and vacuum dried to obtain the active material.

[0012] (4) A preparation method of a reference electrode. A silver / silver ion electrode reference electrode is used, and a 10 mmol / L nitrate acetonitrile solution is used as an internal liquid.

[0013] (5) A preparation method of an ammonium ion battery electrode sheet. The electrode sheet is composed of a current collector and active material, conductive agent and binder with a mass ratio of 7:2:1. The active material is (NH4) x Ni y Mn 1-y [Fe(CN)6] or an aromatic compound or activated carbon. The conductive additive is conductive carbon black; and the binder is polyvinylidene fluoride.

[0014] (6) An assembling method of an organic ammonium ion half battery. First, a conductive electrode and a reference electrode are respectively inserted at the tee joint of the Swagelok joint. Then, a positive electrode sheet, a separator, a negative electrode sheet, and an electrolyte are placed between the conductive electrodes. Finally, the tee joint is sealed with sealing glue, and an organic ammonium ion half battery with good sealing performance is assembled.

[0015] (7) An organic ammonium ion full battery, which is a CR2032 button cell assembled by the above-mentioned positive electrode sheet, negative electrode sheet, electrolyte, and glass fiber separator.

[0016] Compared with the prior art, the organic ammonium ion battery has the following advantages: the organic electrolyte effectively widens the electrochemical window of the ammonium ion battery, avoiding the voltage limitation caused by hydrogen evolution and oxygen evolution reaction. Bis-trifluoromethanesulfonylimide ammonium is easily soluble in carbonate and ether organic solvents, indicating the direction for the popularization and application of different system organic ammonium ion batteries; the novel organic ammonium ion full battery has excellent electrochemical performance, and its wide electrochemical window (0-2.4V) far exceeds the electrochemical window of all current ammonium ion batteries. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which form a part of the present disclosure, are intended to provide further understanding of the present disclosure and are incorporated herein for explanation by way of the exemplary embodiments of the present disclosure and their description. The present disclosure is not limited by the accompanying drawings.

[0018] Figure 1 XRD pattern of (NH4) 1.880 NiHCF,(NH4) 1.634 Ni 0.980 Mn 0.020 HCF,(NH4) 1.911 Ni 0.019 Mn 0.981 HCF and (NH4) 1.892 XRD pattern of MnHCF;

[0019] Figure 2 XRD pattern of (NH4) 1.911 Ni 0.019 Mn 0.981 HCF and Na 1.911 Ni 0.019 Mn 0.981 SEM pattern of MnHCF;

[0020] Figure 3 TEM pattern of (NH4) 1.911 Ni 0.019 Mn 0.981 TEM pattern of MnHCF;

[0021] Figure 4(NH4)2NiHCF for Example 5 of the present application 1.911 Ni 0.019 Mn 0.981 HCF half-cell electrochemical performance chart;

[0022] Figure 5 (NH4)2NiHCF for Example 5 of the present application 1.732 Ni 0.058 Mn 0.942 HCF half-cell electrochemical performance chart;

[0023] Figure 6 (NH4)2NiHCF for Example 5 of the present application 1.880 NiHCF half-cell electrochemical performance chart;

[0024] Figure 7 (NH4)2NiHCF for Example 6 of the present application 1.911 Ni 0.019 Mn 0.981 HCF and PTCDI full-cell electrochemical performance chart; DETAILED DESCRIPTION

[0025] The present application will be described in detail below with reference to the accompanying drawings and examples.

[0026] Example 1

[0027] A series of colorless transparent solutions were obtained by dissolving 2.98 g of ammonium bistrifluoromethanesulfonimide (NH4TFSI) powder in a ml (a = 20, 10, 6.67, 5, 4, 3.33, 2.5, 2) volume ratio of 1:1 ethylene carbonate / diethyl carbonate mixed solution (EC:DEC = 1:1) or tetraethylene glycol dimethyl ether solution (TEGDME) in an argon glove box. After heating at 25°C and stirring at a speed of 400 rpm / min, the solute was fully dissolved in the solvent.

[0028] Example 2

[0029] A method for preparing a positive electrode material for ammonium ion batteries is as follows:

[0030] (1) Na x Ni y Mn 1-y Preparation of HCF precursor:

[0031] b mmol of NiSO4.H2O (b = 0-20) and 10 mmol of sodium citrate were weighed into 100 ml of a c mol / L NaCl solution (c = 0-3.5) to obtain solution A; (1-b) mmol of MnSO4.6H2O and 90 mmol of sodium citrate were weighed into 100 ml of a c mol / L NaCl solution to obtain solution B; 10 mmol of Na4Fe(CN)6 was weighed into 100 ml of a c mol / L NaCl solution to obtain solution C.

[0032] Solution A was added dropwise to solution B at a rate of 1 ml / min using a peristaltic pump; at the same time, solution B was added dropwise to solution C at a rate of 2 ml / min using a peristaltic pump. After the mixed solution was stirred magnetically at 40°C for 6 hours, it was allowed to stand for 2 hours. Finally, the precipitate was separated by centrifugation. The precipitate was washed with ionized water 3 times and, after vacuum drying at 100°C for 12 hours, Na x Ni y Mn 1-y HCF powder was formed.

[0033] (2)(NH4) x Ni y Mn 1-y HCF powder was formed.

[0034] 0.5 g of Na x Ni y Mn 1-y HCF powder was weighed into 50 ml of a 1 mol / L ammonium sulfate solution and stirred at room temperature for 24 h. After centrifugation, the precipitate was washed with deionized water 3 times and vacuum dried at 100°C for 12 h to form (NH4) x Ni y Mn 1-y HCF powder was formed.

[0035] The prussian white material of this example was subjected to XRD testing, and the testing results of (NH4) 1.880 NiHCF, (NH4) 1.634 Ni 0.980 Mn 0.020 HCF, (NH4) 1.911 Ni 0.019 Mn 0.981 HCF and (NH4) 1.892 MnHCF are shown in Table 1. Figure 1

[0036] The prussian white material of this example was subjected to SEM testing, and the testing results of (NH4) 1.911 Ni 0.019 Mn 0.981 HCF are shown in Table 2. Figure 2 ​as shown.

[0037] TEM test was performed on the Prussian white material of the present example, (NH4) 1.911 Ni 0.019 Mn 0.981 The test results of HCF are shown in Figure 3 As can be seen from Figure 2 and Figure 3 It can be seen that the prepared Prussian white material has good uniformity and the particle size is 20-50 nm.

[0038] Example 3

[0039] A preparation method of an electrode active material, 0.5 g of activated carbon is put into 20 ml of 40% hydrofluoric acid, stirred at room temperature for 12 h, washed with deionized water and ethanol for 3 times respectively, and dried at 80°C to obtain the active material.

[0040] Example 4

[0041] A preparation method of an ammonium ion battery positive / negative electrode sheet, the specific preparation method is as follows:

[0042] The above (NH4) x Ni y Mn 1-y HCF powder / PVDF powder, conductive carbon black (Super-P) and 1.5wt% polyvinylidene fluoride solution (PVDF) are uniformly ground in a mortar. Then, an appropriate amount of 1-methyl-2-pyrrolidone (NMP) is added to form a slurry and stirred for 6 hours. Finally, the slurry is uniformly coated on an aluminum foil, vacuum dried at 70°C to obtain a positive / negative electrode sheet. The 1.5wt% polyvinylidene fluoride solution is PVDF powder dissolved in NMP solution.

[0043] The above positive / negative electrode material is cut into a circular electrode sheet with a diameter of 8 mm, and then dried at 100°C under vacuum conditions for 5h, and then transferred to an argon glove box for assembling an organic ammonium ion battery.

[0044] Example 5

[0045] A preparation method of an organic ammonium ion half-cell, the battery mold includes 1 Swagelok three-way joint, 3 matching end sleeves, 2 sealing rings and 2 custom stainless steel columns with a diameter of 13 mm and a length of 7 cm.

[0046] Furthermore, custom stainless steel posts were inserted into both ends of the Swagelok tee connector and sealed using sealing rings and end sleeves. The positive electrode, separator, and negative electrode were then sequentially added between the stainless steel posts. Subsequently, approximately 1 ml of the aforementioned organic electrolyte was dripped into the upper interface of the tee connector, the reference electrode was inserted, and the end sleeve was installed before sealing with sealant. The entire battery assembly process was carried out in an argon-filled glove box, where both water and oxygen pressures were less than 0.1 ppm.

[0047] Using constant current charge / discharge mode, at 0.1A g -1 The Swagelok three-electrode battery of the above embodiment was subjected to constant current charge-discharge tests at the specified current density, with a discharge cutoff voltage of 0V and a charge cutoff voltage of 1.0V. (NH4) 1.911 Ni 0.019 Mn 0.981 HCF, (NH4) 1.732 Ni 0.058 Mn 0.942 HCF and (NH4) 1.880 The results of NiHCF are as follows Figure 4 , Figure 5 and Figure 6 As shown.

[0048] Example 6

[0049] A method for assembling an organic ammonium ion full cell, using the aforementioned Prussian white positive electrode as the positive electrode; PTCDI as the negative electrode; the aforementioned organic ammonium ion solution as the electrolyte; and glass fiber as the separator. The cells are assembled into CR2032 coin cells. The entire assembly process is carried out in an argon-filled glove box, where both water and oxygen pressures are less than 0.1 ppm.

[0050] Using constant current charge / discharge mode, at 0.1A g -1 The organic ammonium ion full cell of the above embodiment was subjected to constant current charge-discharge testing at the specified current density. The discharge cutoff voltage was 0V, and the charge cutoff voltage was 2.4V. The positive electrode was (NH4). 1.911 Ni 0.019 Mn 0.981 The full cell test results are as follows: HCF, PTCDI as the negative electrode, and 1M NH4TFSI dissolved in TEGDME as the electrolyte. Figure 7 As shown.

[0051] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for producing an organic ammonium ion half-cell, characterized by, Comprising the following steps: (1) Preparation of ammonium ion battery cathode material: the precursor Na x Ni y Mn 1-y [Fe(CN)6] is prepared by coprecipitation method, then Na x Ni y Mn 1-y [Fe(CN)6] is mixed with ammonium sulfate solution to carry out ion exchange to obtain a Prussian white material rich in NH4 + , the chemical general formula is (NH4) x Ni y Mn 1-y [Fe(CN)6], wherein x=1.911, y=0.019; (2) Preparation of organic ammonium ion electrolyte: Dissolve bis-trifluoromethanesulfonimide ammonium powder in a mixed solution of ethylene carbonate and diethyl carbonate with a volume ratio of 1:1, heat and stir to prepare electrolytes with concentrations of 0.5 mol / L, 1 mol / L, 2 mol / L, 2.5 mol / L, 3 mol / L, 4 mol / L and 5 mol / L; (3) Preparation of counter electrode active material: Soak activated carbon in hydrofluoric acid, wash with water and ethanol three times respectively, and vacuum dry to obtain the counter electrode active material; (4) Preparation of reference electrode: Use a silver / silver ion electrode reference electrode, and use 10 mmol / L nitrate acetonitrile solution as the built-in liquid; (5) Preparation of ammonium ion battery electrode: the electrode is composed of current collector and active material, conductive agent and binder with mass ratio of 7:2:1; the active material is (NH4) x Ni y Mn 1-y [Fe(CN)6], the conductive agent is conductive carbon black; the binder is polyvinylidene fluoride; (6) Assembly of organic ammonium ion half battery: Insert stainless steel columns at both ends of the Swagelok three-way joint, seal with a sealing ring and an end sleeve, and then add the positive electrode prepared in step (5), the separator and the negative electrode prepared in step (5) between the stainless steel columns, then drop 1 ml of the organic ammonium ion electrolyte prepared in step (2) into the upper end of the three-way joint, insert the reference electrode prepared in step (4) and install the end sleeve, then seal with sealing glue. The entire assembly process of the half battery is carried out in an argon glove box, where the water pressure and oxygen pressure are both less than 0.1 ppm. A well-sealed organic ammonium ion half battery is obtained.

2. The production method according to claim 1, characterized by, The precursor Na in step (1) is prepared by coprecipitation method x Ni y Mn 1-y [Fe(CN)6] comprises the following steps: I. Weigh b mmol of NiSO4·H2O and 10 mmol of sodium citrate into 100 ml of cmol / L NaCl solution to obtain solution A, where b is 0-20 and c is 0-3.5; weigh 1-b mmol of MnSO4·6H2O and 90 mmol of sodium citrate into 100 ml of cmol / L NaCl solution to obtain solution B; weigh 10 mmol of Na4Fe(CN)6 into 100 ml of cmol / L NaCl solution to obtain solution C; II. Solution A is added to solution B at a rate of 1 ml / min using a peristaltic pump; Solution B with solution A is added to solution C at a rate of 2 ml / min using a peristaltic pump; The mixed solution was magnetically stirred at 40°C for 6 hours, left to stand for 2 hours, and finally the precipitate was separated by a centrifuge. The precipitate was washed with deionized water 3 times and formed Na x Ni y Mn 1-y HCF powder.

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