A magnesium / sulfinyl chloride primary battery and methods of making and recycling the same

Abstract

The application belongs to the field of batteries, and particularly relates to a magnesium / thionyl chloride primary battery and a preparation and recovery method thereof. The magnesium / thionyl chloride primary battery is prepared by using a metal material loaded with a carbon material as a positive electrode, thionyl chloride / metal chloride as an electrolyte, and magnesium foil or magnesium alloy as a negative electrode, and the magnesium / thionyl chloride primary battery has excellent electrochemical performance. Through optimization and control of the electrode material and electrolyte components, the discharge capacity and shelf performance of the battery are improved. In addition, the positive and negative electrodes of the obtained battery can be recycled and reused through a simple method after service, which significantly improves the economic benefit and environmental friendliness of the battery. The magnesium / thionyl chloride primary battery has the characteristics of high performance, sustainability and low cost, and provides a new idea and scheme for developing high-performance primary batteries.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of batteries, and particularly relates to a magnesium / thionyl chloride primary battery and a preparation and recovery method thereof, in particular to a high-performance, recyclable and low-cost magnesium / thionyl chloride primary battery and a preparation and recovery method thereof. BACKGROUND

[0002] Since the first commercial lithium-ion battery was introduced in the 1990s, lithium-ion batteries have greatly promoted the development of human economy and society, and provided power for realizing a green and pollution-free society. [1-4] Lithium / thionyl chloride primary batteries are widely used in important fields such as industrial equipment, medical health and aerospace due to their high energy density and long storage life. [5-9] The battery is discharged once by oxidation of the lithium negative electrode and reduction of the positive electrode thionyl chloride into sulfur, sulfur dioxide and chloride ions. [10,11] Chloride ions react with lithium ions stripped from the lithium negative electrode to form lithium chloride deposited on the surface of the carbon positive electrode, and the battery discharge process is terminated when the positive electrode is completely passivated. [7,12,13] Such a battery can provide a high specific capacity of about 2,300 mAh g -1 and a high energy density of up to 590 Wh kg -1 in a single discharge. [14,15] Over the past 50 years, researchers have made a series of attempts to optimize the discharge capacity and rate performance of lithium / thionyl chloride primary batteries, making them an important branch of primary battery systems. [16-18]

[0003] Although lithium / thionyl chloride primary batteries have outstanding advantages, their practical application is still subject to many limitations. For example, the low crust abundance (0.0017%) of lithium element greatly restricts the large-scale application of lithium / thionyl chloride primary batteries. [19-22] At the same time, the high reactivity of lithium metal poses a challenge to the safety of the battery system and significantly increases the complexity of battery production and recycling. In addition, the energy density of lithium / thionyl chloride primary batteries based on single-electron redox reactions still needs to be further improved to fully meet the endurance requirements of various applications. [23,24] Therefore, it is of important application value to develop a new thionyl chloride battery based on multivalent metals with high performance, recyclability and low cost.

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[0029] In view of the deficiencies of the prior art, the purpose of the present application is to provide a magnesium / thionyl chloride primary battery and a preparation and recovery method thereof. The primary battery is reasonably regulated through the research on the electrolyte solvation and the positive electrode reaction process, so as to obtain a magnesium / thionyl chloride primary battery with excellent electrochemical performance, and the positive electrode sheet and the negative electrode sheet of the primary battery can be recovered by a simple method, so that the used positive and negative electrode sheets and the new electrolyte are used to assemble a new magnesium / thionyl chloride primary battery.

[0030] To achieve the purpose of the present application, the following technical solutions are adopted:

[0031] In a first aspect, the present application provides a magnesium / thionyl chloride primary battery, comprising a positive electrode sheet, a negative electrode sheet and an electrolyte.

[0032] The positive electrode sheet is a metal material loaded with a carbon material.

[0033] The negative electrode sheet is a magnesium foil or a magnesium alloy foil.

[0034] The solvent of the electrolyte is thionyl chloride and the solute is a metal chloride; the concentration of the metal chloride in the electrolyte is 1-5 mol / L. -1 .

[0035] Preferably, the carbon material comprises any one of graphite, conductive carbon black, carbon nanotubes or graphene.

[0036] The metal material is selected from any one of foamed nickel and stainless steel foil.

[0037] Preferably, the conductive carbon black includes any one of acetylene black, ketjen black.

[0038] More preferably, the carbon material is conductive carbon black, most preferably the carbon material is ketjen black.

[0039] Preferably, the method for preparing the positive electrode sheet includes the following steps:

[0040] (a) Preparation of carbon slurry: weigh a certain amount of carbon material particles and binder, and add solvent, and ultrasonically treat or grind the resulting mixture until the carbon material particles are uniformly dispersed in the solvent, thereby obtaining the carbon slurry;

[0041] (b) Preparation of positive electrode sheet: drop or coat the prepared carbon slurry onto the metal material, and then dry and compact, thereby obtaining the positive electrode sheet.

[0042] Preferably, in step (a), the binder includes polytetrafluoroethylene emulsion;

[0043] The solvent includes ethanol, N-methylpyrrolidone;

[0044] The mass ratio of the carbon material particles to the binder is 9:1;

[0045] In step (b), the carbon material loading is 0.1-3 mg / cm 2 .

[0046] Preferably, when the positive electrode sheet is a foam nickel loaded with carbon material, the method for preparing the same is:

[0047] (a1) Preparation of carbon slurry: weigh a certain amount of carbon material particles and binder, and add ethanol, and ultrasonically treat the resulting mixture until the carbon material particles are uniformly dispersed in the solvent, thereby obtaining the carbon slurry;

[0048] (b1) Preparation of positive electrode sheet: drop the prepared carbon slurry onto the dried foam nickel, and then dry and compact, thereby obtaining the positive electrode sheet.

[0049] More preferably, in step (a1), after the dried foam nickel is placed on a hot stage at a temperature of 75-85°C, the carbon slurry is started to be dropped; more preferably, the hot stage is at 80°C.

[0050] When the carbon slurry is dropped, the solvent in the carbon slurry dropped in the previous time needs to be evaporated completely before the carbon slurry in the next time is dropped.

[0051] Preferably, when the positive electrode sheet is a stainless steel foil loaded with carbon material, the method for preparing the same is:

[0052] (a2) Preparation of carbon slurry: weigh a certain amount of carbon material particles and binder, add N-methyl pyrrolidone, and grind the mixture until it is uniformly dispersed, thereby obtaining a carbon slurry;

[0053] (b2) Preparation of positive electrode sheet: coat the prepared carbon slurry on a clean stainless steel foil, and then dry and compact it, thereby obtaining a positive electrode sheet.

[0054] Preferably, the metal chloride comprises aluminum chloride with a concentration of 1-4 mol L -1 and magnesium chloride with a concentration of 0-1.5 mol L -1 .

[0055] Preferably, the metal chloride comprises aluminum chloride with a concentration of 1-3 mol L -1 and magnesium chloride with a concentration of 0.4-1.2 mol L -1 .

[0056] More preferably, the metal chloride comprises aluminum chloride with a concentration of 2 mol L -1 and magnesium chloride with a concentration of 0.6-0.8 mol L -1 .

[0057] Preferably, the material of the negative electrode is a magnesium foil or a magnesium-aluminum alloy foil.

[0058] Preferably, the negative electrode is obtained by cutting a magnesium foil or a magnesium-aluminum alloy foil into a desired size, and then removing surface oxides with sandpaper.

[0059] Preferably, the magnesium / thionyl chloride primary battery further comprises a negative electrode shell, a gasket, a spring, a separator loaded with electrolyte, and a positive electrode shell; the positive electrode shell and the negative electrode shell are sealingly connected; wherein the spring, the gasket, and the negative electrode sheet are sequentially arranged in the negative electrode shell, the positive electrode sheet is arranged in the positive electrode shell, and the separator loaded with electrolyte is arranged between the positive electrode sheet and the negative electrode sheet.

[0060] In a second aspect, the present application provides a preparation method of a magnesium / thionyl chloride primary battery, comprising the following steps:

[0061] A. Preparation of a positive electrode sheet and a negative electrode sheet; preparation of an electrolyte;

[0062] B. Sequentially placing a spring and a gasket in a negative electrode shell, then sequentially placing a negative electrode sheet and a separator on the gasket, injecting an electrolyte into the separator, placing a positive electrode sheet, and sealing with a positive electrode shell, thereby obtaining a magnesium / thionyl chloride primary battery.

[0063] In a third aspect, the present application provides a recycling method of a magnesium / thionyl chloride primary battery, comprising the following steps:

[0064] After the magnesium / thionyl chloride primary battery is discharged, the resulting positive and negative electrode sheets are cleaned and dried to obtain the recovered positive and negative electrode sheets.

[0065] Preferably, the cleaning solution used for cleaning is anhydrous ethanol;

[0066] The drying process specifically involves drying the positive electrode at 80°C and drying the negative electrode at room temperature.

[0067] Compared with the prior art, the present invention has the following beneficial effects:

[0068] This invention utilizes carbon material as the positive electrode, a metal chloride dissolved in thionyl chloride as the electrolyte, and magnesium foil or magnesium alloy as the negative electrode to prepare a magnesium / thionyl chloride primary battery with high electrochemical performance, recyclability, and low cost. The redox reaction between magnesium and thionyl chloride leads to the formation of discharge products such as magnesium chloride, sulfur, and sulfur dioxide. By adjusting the positive electrode material and electrolyte, the discharge capacity and shelf life of the battery are optimized. The optimized magnesium / thionyl chloride primary battery provides a flat discharge plateau at 1.62V and, based on the mass of carbon, can deliver up to 11,000 mAh g⁻¹. -1 The battery exhibits a high discharge specific capacity. After 20 days of storage, it retains 99.3% of its original capacity. The positive and negative electrodes of the failed battery can be easily recovered to produce a recyclable primary battery. The magnesium / thionyl chloride primary battery proposed in this invention holds promise for opening up a new direction for the development of high-performance primary batteries towards recyclability and low cost. Attached Figure Description

[0069] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0070] Figure 1 This is a schematic diagram of a magnesium / thionyl chloride primary battery, with nickel foam loaded with carbon material as the positive electrode, magnesium foil as the negative electrode, and aluminum chloride and magnesium chloride dissolved in thionyl chloride as the electrolyte.

[0071] Figure 2 The constant current discharge curve and discharge curves before and after battery storage are shown for the magnesium / thionyl chloride primary battery prepared according to this invention; wherein... Figure 2 a represents the magnesium / thionyl chloride primary battery in Example 1 of this invention, using 2 mol L dissolved in thionyl chloride. -1 Aluminum chloride and 0.8 mol L -1 When magnesium chloride is used as the electrolyte, at a current density of 100 mA g -1 The constant current discharge curve at that time; Figure 2 b represents 2 mol L dissolved in thionyl chloride.-1 aluminum chloride and 0.8 mol L -1 magnesium chloride, 2 mol L -1 aluminum chloride as electrolyte, discharge curves before and after the battery was stored for 20 days, solid line and dotted line represent before storage and after storage for 20 days, respectively.

[0072] Figure 3 magnesium chloride, 2 mol L -1 aluminum chloride and 0.8 mol L -1 magnesium chloride as electrolyte, negative electrode is magnesium-aluminum alloy, constant current discharge curve at current density of 100 mA g -1

[0073] Figure 4 magnesium chloride, 2 mol L -1 aluminum chloride and 0.8 mol L -1 magnesium chloride as electrolyte, negative electrode is magnesium foil, positive electrode is stainless steel foil loaded with carbon material, constant current discharge curve at current density of 100 mA g -1

[0074] Figure 5 optical photos of each component of magnesium / thionyl chloride primary battery after disassembly in Example 4 of the present application.

[0075] Figure 6 specific capacity and average discharge platform of magnesium / thionyl chloride primary battery before and after recovery in Example 4 of the present application; wherein, dark column chart is specific capacity, light column chart is average voltage platform.

[0076] Figure 7 magnesium chloride, 2 mol L -1 aluminum chloride as electrolyte, constant current discharge curve at current density of 100 mA g -1

[0077] Figure 8 magnesium chloride, 2 mol L -1 aluminum chloride as electrolyte, constant current discharge curve at current density of 100 mA g -1

[0078] Figure 9 magnesium chloride, 2 mol L -1 aluminum chloride and 0.8 mol L​​​​-1 Magnesium chloride was used as electrolyte, acetylene black was used as carbon positive electrode, and constant current discharge curve was measured at current density of 100 mA g -1

[0079] Figure 10 A magnesium / thionyl chloride primary battery in Example 8 of the present invention was used with 2 mol L -1 Aluminum chloride and 0.8 mol L -1 Magnesium chloride was used as electrolyte, flake graphite was used as carbon positive electrode, and constant current discharge curve was measured at current density of 100 mA g -1

[0080] Figure 11 A magnesium / thionyl chloride primary battery in Example 9 of the present invention was used with 1 mol L -1 Aluminum chloride and 0.4 mol L -1 Magnesium chloride was used as electrolyte, magnesium foil was used as negative electrode, and constant current discharge curve was measured at current density of 100 mA g -1

[0081] Figure 12 A magnesium / thionyl chloride primary battery in Example 10 of the present invention was used with 3 mol L -1 Aluminum chloride and 1.2 mol L -1 Magnesium chloride was used as electrolyte, magnesium foil was used as negative electrode, and constant current discharge curve was measured at current density of 100 mA g -1

[0082] Figure 13 A magnesium / thionyl chloride primary battery in Example 11 of the present invention was used with 2 mol L -1 Aluminum chloride and 0.4 mol L -1 Magnesium chloride was used as electrolyte, magnesium foil was used as negative electrode, and constant current discharge curve was measured at current density of 100 mA g -1

[0083] Figure 14 A magnesium / thionyl chloride primary battery in Example 12 of the present invention was used with 2 mol L -1 Aluminum chloride and 0.6 mol L -1 Magnesium chloride was used as electrolyte, magnesium foil was used as negative electrode, and constant current discharge curve was measured at current density of 100 mA g -1

[0084] Figure 15 Analysis of products on positive electrode during discharge process of magnesium / thionyl chloride primary battery. Figure 15 a- Figure 15 ​​​​​​d is a scanning electron microscope image of the discharge product on the Ketjen black cathode at a discharge current density of 100 mA g -1 , the discharge product gradually covers the entire surface of the cathode, Figure 15 a- Figure 15 The scale in d is 500 nanometers; Figure 15 e is an energy spectrum of the cathode after complete discharge, proving that the discharge product is composed of magnesium chloride and sulfur, Figure 15 The scale in e is 10 microns.

[0085] Figure 16 Analysis of the discharge product on the Ketjen black cathode in a magnesium / thionyl chloride primary battery. Figure 16 a- Figure 16 b is an X-ray photoelectron spectrum of the cathode after discharge of the battery; Figure 16 c is an X-ray diffraction spectrum of the cathode of the battery at different discharge depths; Figure 16 d is a depth profile of MgCl3 - , MgCl2 - , S - and C - ion fragments on the cathode after discharge by time-of-flight secondary ion mass spectrometry; Figure 16 e is a three-dimensional distribution of MgCl3 - , MgCl2 - , S - and C - ion fragments, with an analysis area of 100 x 100 μm 2 ; Figure 16 f is Figure 16 the corresponding cross-sectional image in e; Figure 16 g is a schematic diagram of the distribution of the discharge product on the cathode carbon material.

[0086] Figure 17 Application demonstration of a magnesium / thionyl chloride primary battery; Figure 17 a is a schematic diagram of a wearable application; Figure 17 b- Figure 17 c, a commercial electronic watch is driven in air and water, respectively, using a magnesium / thionyl chloride primary battery, Figure 17 The scales in b and Figure 17 c are 1 centimeter and 5 centimeters, respectively; Figure 17 d is the use of a magnesium / thionyl chloride primary battery to drive 37 light-emitting diodes, Figure 17 The scale in d is 5 centimeters; Figure 17 e is the use of a magnesium / thionyl chloride primary battery to drive smart glasses, Figure 17 The scale in e is 5 centimeters. DETAILED DESCRIPTION

[0087] The application will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the application, but do not limit the application in any form. It should be pointed out that, for those skilled in the art, without departing from the concept of the application, a number of modifications and improvements can be made. These all belong to the protection scope of the application.

[0088] The following example provides a magnesium / thionyl chloride primary battery, which uses a metal material loaded with a carbon material as a positive electrode sheet, a magnesium foil or a magnesium alloy foil as a negative electrode sheet, and thionyl chloride / metal chloride as an electrolyte. The battery also includes a negative electrode shell, a gasket, a spring, an electrolyte-loaded separator, and a positive electrode shell; the positive electrode shell and the negative electrode shell are sealingly connected; wherein the spring, the gasket, and the negative electrode sheet are sequentially arranged in the negative electrode shell, the positive electrode sheet is arranged in the positive electrode shell, and the electrolyte-loaded separator is arranged between the positive electrode sheet and the negative electrode sheet.

[0089] The solvent of the electrolyte is thionyl chloride and the solute is metal chloride, and the concentration of the metal chloride is 1-5 mol / L. -1 Specifically, the metal chloride includes aluminum chloride with a concentration of 1-4 mol / L -1 and magnesium chloride with a concentration of 0-1.5 mol / L -1 .

[0090] The carbon material includes any one of graphite, conductive carbon black, carbon nanotubes, or graphene; and the metal material is selected from any one of foamed nickel and stainless steel foil.

[0091] The following example also provides a preparation method of the magnesium / thionyl chloride primary battery, which includes:

[0092] A. Preparing the positive electrode sheet and the negative electrode sheet; preparing the electrolyte;

[0093] B. Placing the spring and the gasket in the negative electrode shell in sequence, then placing the negative electrode sheet and the separator on the gasket in sequence, injecting the electrolyte into the separator, and then placing the positive electrode sheet, and sealing with the positive electrode shell, to obtain the magnesium / thionyl chloride primary battery.

[0094] The magnesium / thionyl chloride primary battery prepared in the following example can be recycled by a simple method after service. Specifically, the discharged magnesium / thionyl chloride primary battery is disassembled, and the obtained positive electrode sheet and negative electrode sheet are washed and dried, to obtain the recycled positive electrode sheet and negative electrode sheet. The recycled positive electrode sheet and negative electrode sheet can be assembled into a new battery with new electrolyte.

[0095] The technical solutions of the application will be further described below with reference to specific examples.

[0096] Example 1

[0097] The present embodiment provides a preparation method of a magnesium / thionyl chloride primary battery, comprising the following steps:

[0098] (1) Preparation of thionyl chloride electrolyte: In an argon-filled glove box, aluminum chloride was weighed, and thionyl chloride was added thereto. The concentration of aluminum chloride was 2 mol / L -1 . The mixture was fully stirred on a magnetic stirrer to ensure that the solid was fully dissolved in the thionyl chloride. 0.8 mol / L -1 of magnesium chloride was added to the above electrolyte to obtain a low-concentration electrolyte containing magnesium chloride.

[0099] (2) Preparation of carbon positive electrode sheet: A certain amount of Ketjen black nanoparticles and polytetrafluoroethylene emulsion binder (mass ratio of 9:1) were weighed, and a certain amount of ethanol was added. The mixture was ultrasonically treated until the carbon particles were uniformly dispersed in the ethanol to obtain a carbon slurry. The surface impurities of the foam nickel were removed, and then the foam nickel was washed with deionized water and ethanol, and dried in a drying oven at 80°C for 1 hour. The dried foam nickel was placed on a hot stage at a temperature of 80°C, and the prepared carbon slurry was dropped onto the foam nickel. After the solvent in the carbon slurry dropped in the previous step was evaporated, the carbon slurry was dropped again until the loading amount of the carbon material met the expectation (in the foam nickel loaded with the carbon material obtained in the present embodiment, the loading amount of Ketjen black was 1-2 mg / cm 2 ). The fully dried electrode sheet was compacted to obtain a carbon positive electrode sheet.

[0100] (3) Preparation of negative electrode sheet: The magnesium foil was cut into the required size, and the surface oxide was removed with sandpaper.

[0101] (4) Assembly of battery: The battery shell included a positive shell and a negative shell, both of which were made of 316 stainless steel. A glass fiber (GF / D) filter membrane was used as a separator to load the thionyl chloride electrolyte prepared in step (1). The spring and the gasket were placed in the negative shell in sequence, and then the negative electrode sheet and the separator were placed on the gasket in sequence. The electrolyte was injected into the separator, and then the positive electrode sheet was placed. The positive shell was sealed. After the magnesium / thionyl chloride primary battery was packaged by using a pressure-controllable electric button cell packaging machine, the edges of the battery were further packaged with sealing silicone to prevent water and air from entering the battery. The schematic diagram of the obtained magnesium / thionyl chloride primary battery is shown in Figure 1 .

[0102] The magnesium / thionyl chloride primary battery prepared in the present embodiment was subjected to battery discharge performance test. The discharge current was 100 mA / g -1 , and the discharge cut-off voltage was 0.01 V vs. Mg. The battery discharge curve is shown in Figure 2 a. The average discharge voltage plateau was 1.62 V, and the specific discharge capacity was 11131 mAh / g -1The electrolyte used in Examples 5 and 6 was magnesium chloride-free and contained a solute of 4 mol / L. -1 Compared to high-concentration aluminum chloride electrolytes, this electrolyte exhibits a higher average discharge voltage plateau and discharge specific capacity. The battery shelf performance of the magnesium / thionyl chloride primary battery prepared in this example is as follows: Figure 2 As shown in b (with the curve indicating magnesium chloride), this is different from the primary battery prepared in Example 5 using an electrolyte without magnesium chloride. Figure 2 Compared to curve b (without magnesium chloride), after 20 days of storage, no significant change in discharge voltage was observed in the battery assembled with an electrolyte containing magnesium chloride, and the discharge specific capacity retained 99.3% of the original specific capacity. In terms of initial voltage hysteresis, the battery using an electrolyte without magnesium chloride showed obvious voltage hysteresis in the initial discharge stage, indicating that the battery polarization caused by the passivation of the magnesium metal negative electrode during storage was more severe.

[0103] The product analysis results on the positive electrode during the discharge process of the magnesium / thionyl chloride primary battery prepared in the embodiments of the present invention are as follows: Figure 15 As shown, Figure 15 a- Figure 15 d is a scanning electron microscope image of the discharge products on the Ketjen Black cathode, with a discharge current density of 100 mA g. -1 The discharge products gradually cover the entire surface of the positive electrode; Figure 15 e is the positive electrode energy spectrum after complete discharge, proving that the discharge products consist of magnesium chloride and sulfur.

[0104] The analytical results of the discharge products on the Ketjen black cathode in the magnesium / thionyl chloride primary battery prepared in the embodiments of the present invention are as follows: Figure 16 As shown, Figure 16 a- Figure 16 b is the X-ray photoelectron spectrum of the positive electrode after the battery is discharged; Figure 16 c represents the X-ray diffraction pattern of the battery's positive electrode at different depths of discharge; Figure 16 d represents the MgCl3 on the positive electrode after discharge, obtained by time-of-flight secondary ion mass spectrometry. - MgCl2 - S - and C - In-depth analysis of ion fragments; Figure 16 e is MgCl3 - MgCl2 - S - and C - Three-dimensional distribution of ion fragments, with an analytical area of ​​100 × 100 μm. 2 ; Figure 16 f is Figure 16 The corresponding cross-sectional image in e; Figure 16 g is a schematic diagram showing the distribution of discharge products on the cathode carbon material.

[0105] Example 2

[0106] The present example provides a method for preparing a magnesium / thionyl chloride primary battery, comprising the following steps:

[0107] (1) Preparation of electrolyte: In an argon-filled glove box, aluminum chloride was weighed, and thionyl chloride was added thereto. The concentration of aluminum chloride was 2 mol / L -1 . The mixture was placed on a magnetic stirrer for sufficient stirring to ensure that the solid was fully dissolved in the thionyl chloride. 0.8 mol / L -1 of magnesium chloride was added to the above electrolyte to obtain a low-concentration electrolyte containing magnesium chloride.

[0108] (2) Preparation of carbon positive electrode sheet: A certain amount of Ketjen black nanoparticles and polytetrafluoroethylene emulsion binder (mass ratio of 9:1) were weighed, and a certain amount of ethanol was added. The mixture was ultrasonically treated until the carbon particles were uniformly dispersed in the ethanol to obtain a carbon slurry. The surface impurities of the foam nickel were removed, and then the foam nickel was washed with deionized water and ethanol, respectively, and dried in a drying oven at 80°C for 1 hour. The dried foam nickel was placed on a hot stage at a temperature of 80°C, and the prepared carbon slurry was dropped onto the foam nickel. After the solvent in the carbon slurry dropped in the previous step was evaporated, the carbon slurry was dropped again until the loading amount of the carbon material met the expectation (in the foam nickel loaded with the carbon material obtained in the present example, the loading amount of Ketjen black was 1-2 mg / cm 2 ). The completely dried electrode sheet was compacted to obtain a carbon positive electrode sheet.

[0109] (3) Preparation of negative electrode sheet: The magnesium-aluminum alloy foil (AZ91D) was cut into the required size, and the surface oxide was removed with sandpaper.

[0110] (4) Assembly of battery: The battery shell included a positive shell and a negative shell, both of which were made of 316 stainless steel. A glass fiber (GF / D) filter membrane was used as a separator to load the thionyl chloride electrolyte prepared in step (1). The spring and the gasket were placed in the negative shell in sequence, and then the negative electrode sheet and the separator were placed on the gasket in sequence. The electrolyte was injected into the separator, and then the positive electrode sheet was placed. The positive shell was sealed. After the magnesium / thionyl chloride primary battery was packaged using a pressure-controllable electric button cell packaging machine, the edges of the battery were further packaged with sealing silicone to prevent water and air from entering the battery.

[0111] The magnesium / thionyl chloride primary battery prepared in the present example was subjected to battery discharge performance test. The discharge current was 100 mA g -1 , and the discharge cut-off voltage was 0.01 V vs. Mg. The battery discharge curve is shown in Figure 3 . The average discharge voltage plateau was 1.52 V, and the specific discharge capacity was 8579 mAh g -1 .

[0112] Example 3

[0113] The present example provides a preparation method of a magnesium / thionyl chloride primary battery, comprising the following steps:

[0114] (1) Preparation of thionyl chloride electrolyte: In an argon-filled glove box, aluminum chloride was weighed, and thionyl chloride was added thereto. The concentration of aluminum chloride was 2 mol / L -1 . The mixture was placed on a magnetic stirrer for sufficient stirring to ensure that the solid was fully dissolved in the thionyl chloride. 0.8 mol / L -1 of magnesium chloride was further added to the above electrolyte to obtain a low-concentration electrolyte containing magnesium chloride.

[0115] (2) Preparation of carbon positive electrode sheet: A certain amount of Ketjen black nanoparticles and polytetrafluoroethylene binder (mass ratio of 9:1) were weighed, and a certain amount of N-methyl pyrrolidone was added. The mixture was ground in a mortar until the mixture was uniformly dispersed to obtain a carbon slurry. The obtained carbon slurry was uniformly coated on a clean stainless steel foil (carbon material loading amount was 0.31 mg / cm 2 ), and dried in a drying oven at 80°C for 12 hours. The completely dried electrode sheet was rolled with a roller press to obtain a carbon positive electrode sheet.

[0116] (3) Preparation of negative electrode sheet: The magnesium foil was cut into the required size, and the surface oxide was removed with sandpaper.

[0117] (4) Assembly of battery: The battery shell includes a positive shell and a negative shell, both of which are made of 316 stainless steel. The separator is a glass fiber (GF / D) filter membrane, which is used to load the thionyl chloride electrolyte prepared in step (1). The spring and the gasket were placed in the negative shell in sequence, then the negative electrode sheet and the separator were placed on the gasket in sequence, and then the electrolyte was injected into the separator. The positive electrode sheet was then placed, and the positive shell was sealed. After the magnesium / thionyl chloride primary battery was packaged by a pressure-controllable electric button cell packaging machine, the edges of the battery were further packaged with sealing silicone to prevent water and air from entering the battery.

[0118] The magnesium / thionyl chloride primary battery prepared in the present example was subjected to battery discharge performance test, and the discharge current was 100 mA g -1 , and the discharge cut-off voltage was 0.01 V vs. Mg. The test results (as shown in Figure 4 ) were as follows: the average discharge voltage plateau was 1.60 V, and the specific discharge capacity was 8756 mAh g -1 .

[0119] Example 4

[0120] The present example provides a preparation method of a magnesium / thionyl chloride primary battery, comprising the following steps:

[0121] (1) Preparation of thionyl chloride electrolyte: In an argon-filled glove box, aluminum chloride was weighed, and thionyl chloride was added to it. The concentration of aluminum chloride was 2 mol L -1 , and it was placed on a magnetic stirrer for thorough stirring to ensure that the solid was fully dissolved in thionyl chloride. 0.8 mol L -1 of magnesium chloride was added to the above electrolyte to obtain a low-concentration electrolyte containing magnesium chloride.

[0122] (2) Preparation of carbon positive electrode sheet: A certain amount of Ketjen black nanoparticles and polytetrafluoroethylene emulsion binder (mass ratio of 9:1) were weighed, and a certain amount of ethanol was added. The mixture was ultrasonically treated until the carbon particles were uniformly dispersed in the ethanol to obtain a carbon slurry. The surface impurities of the foam nickel were removed, and deionized water and ethanol were used to rinse it in turn. The foam nickel was dried in a drying oven at 80°C for 1 hour. The dried foam nickel was placed on a hot stage at a temperature of 80°C, and the prepared carbon slurry was dropped onto the foam nickel. After the solvent in the carbon slurry dropped in the previous time was evaporated, the carbon slurry was added again until the loading amount of the carbon material met the expectation (in the foam nickel loaded with the carbon material obtained in this example, the loading amount of Ketjen black was 1-2 mg / cm 2 ). The completely dried electrode sheet was compacted to obtain a carbon positive electrode sheet.

[0123] (3) Preparation of negative electrode sheet: The magnesium foil was cut into the required size, and the surface oxide was removed with sandpaper.

[0124] (4) Assembly of battery: The battery shell included a positive shell and a negative shell, both of which were made of 316 stainless steel. The separator was a glass fiber (GF / D) filter membrane, and it was used to load the thionyl chloride electrolyte prepared in step (1). The spring and the gasket were placed in the negative shell in turn, and then the negative electrode sheet and the separator were placed on the gasket in turn. The electrolyte was injected into the separator, and then the positive electrode sheet was placed. The positive shell was sealed. After the magnesium / thionyl chloride primary battery was packaged using a pressure-controllable electric button cell packaging machine, the edges of the battery were further packaged with sealing silicone to prevent water and air from entering the battery.

[0125] (5) Recovery of battery: After the magnesium / thionyl chloride primary battery was discharged, the components were disassembled as shown in Figure 5 . The positive electrode sheet and the negative electrode sheet were taken out, and the positive electrode sheet and the negative electrode sheet were washed in air with anhydrous ethanol. After washing, the positive electrode sheet and the negative electrode sheet were dried at 80°C and room temperature, respectively. The recovered positive electrode sheet and the negative electrode sheet were obtained.

[0126] The recovered positive electrode sheet and the negative electrode sheet were assembled into a new battery with new electrolyte (the assembly method was consistent with the previous step). The discharge performance test of the battery was carried out, and the discharge current was 200 mA g -1The discharge cutoff voltage is 0.01V vs. Mg. The discharge performance of the new battery is as follows: Figure 6 As shown in the figure (the result indicated by "Recovery"), the average discharge voltage plateau is 1.56V, and the discharge specific capacity is 10083mAh g. -1 , with the original battery ( Figure 6 The discharge capacity (11437 mAh g) is shown in the "original" result. -1 In contrast, recycled batteries can retain nearly 90% of their discharge capacity.

[0127] Example 5

[0128] This embodiment provides a method for preparing a magnesium / thionyl chloride primary battery, including the following steps:

[0129] (1) Preparation of electrolyte: Weigh aluminum chloride in a glove box filled with argon atmosphere, add thionyl chloride to it, and the concentration of aluminum chloride is 2 mol / L. -1 Place the mixture on a magnetic stirrer and stir thoroughly to ensure that the solid is fully dissolved in thionyl chloride to obtain a low-concentration electrolyte.

[0130] (2) Preparation of carbon cathode sheet: Weigh a certain amount of Ketjenblack nanoparticles and polytetrafluoroethylene emulsion binder (mass ratio 9:1), add a certain amount of ethanol, and sonicate the mixture until the carbon particles are uniformly dispersed in the ethanol to obtain carbon slurry. Remove impurities from the surface of the nickel foam and rinse it with deionized water and ethanol in sequence, and dry it in a drying oven at 80°C for 1 hour. Place the dried nickel foam on a hot plate at 80°C, and drop the prepared carbon slurry onto the nickel foam. Wait for the solvent in the carbon slurry added in the previous drop to evaporate before adding more carbon slurry, until the carbon material loading meets the expectation (in this example, the Ketjenblack loading in the nickel foam loaded with carbon material is 1-2 mg / cm³). 2 The completely dried electrode sheet is compacted to obtain a carbon positive electrode sheet.

[0131] (3) Preparation of negative electrode: cut magnesium foil into the required size and remove surface oxides with sandpaper.

[0132] (4) Battery assembly: The battery casing includes a positive electrode casing and a negative electrode casing, both made of 316 stainless steel. The separator is a glass fiber (GF / D) filter membrane used to load the thionyl chloride electrolyte prepared in step (1). The spring and gasket are placed sequentially in the negative electrode casing, followed by the negative electrode sheet and separator on the gasket. Electrolyte is then injected into the separator, and the positive electrode sheet is placed next. The positive electrode casing is then used to seal the casing. Specifically, a pressure-controlled electric button cell battery packaging machine is used to package the magnesium / thionyl chloride primary battery. The edges of the battery are then further sealed with sealing silicone to prevent water and air from entering the battery.

[0133] The magnesium / thionyl chloride primary battery prepared in this example was subjected to battery discharge performance test, the discharge current was 100 mA g -1 , and the discharge cut-off voltage was 0.01 V vs. Mg. The battery discharge curve is shown in Figure 7 , the average discharge voltage plateau was 1.59 V, and the specific discharge capacity was 8258 mAh g -1 .

[0134] Example 6

[0135] This example provides a preparation method of a magnesium / thionyl chloride primary battery, comprising the following steps: (1) preparation of electrolyte: in an argon-filled glove box, aluminum chloride was weighed, and thionyl chloride was added thereto, the concentration of aluminum chloride was 4 mol L -1 , and it was placed on a magnetic stirrer for sufficient stirring to ensure that the solid was fully dissolved in the thionyl chloride to obtain a high-concentration electrolyte.

[0136] (2) preparation of carbon positive electrode sheet: a certain amount of ketchen black nanoparticles and polytetrafluoroethylene emulsion binder (mass ratio of 9:1) were weighed, a certain amount of ethanol was added, and the mixture was ultrasonically treated until the carbon particles were uniformly dispersed in the ethanol to obtain a carbon slurry. The surface impurities of the foam nickel were removed, and then deionized water and ethanol were used for washing, and the foam nickel was dried in a drying box at 80°C for 1 hour. The dried foam nickel was placed on a hot stage at a temperature of 80°C, and the prepared carbon slurry was dropped onto the foam nickel. After the solvent in the carbon slurry dropped in the previous time was evaporated completely, the carbon slurry was dropped again until the loading amount of the carbon material obtained met the expectation (in the foam nickel loaded with the carbon material obtained in this example, the loading amount of ketchen black was 1-2 mg / cm 2 ). The fully dried electrode sheet was compacted to obtain a carbon positive electrode sheet.

[0137] (3) preparation of negative electrode sheet: magnesium foil was cut into the required size, and the surface oxide was removed with sandpaper.

[0138] (4) assembly of battery: the battery shell included a positive shell and a negative shell, both of which were made of 316 stainless steel, and the separator was a glass fiber (GF / D) filter membrane, which was used to load the thionyl chloride electrolyte prepared in step (1). The spring and the gasket were placed in the negative shell in sequence, then the negative electrode sheet and the separator were placed on the gasket in sequence, and then the electrolyte was injected into the separator, and the positive electrode sheet was placed, and the positive shell was sealed. After the magnesium / thionyl chloride primary battery was packaged by using a pressure-controllable electric button cell packaging machine, the edges of the battery were further packaged with sealing silicone to prevent water and air from entering the battery.

[0139] The magnesium / thionyl chloride primary battery prepared in this example was subjected to battery discharge performance test, the discharge current was 100 mA g -1The discharge cutoff voltage is 0.01V vs. Mg. The battery discharge curve is as follows. Figure 8 As shown, the average discharge voltage plateau is 0.2V, and the discharge specific capacity is 2461mAh g. -1 .

[0140] Example 7

[0141] This embodiment provides a method for preparing a magnesium / thionyl chloride primary battery, including the following steps: (1) Preparation of thionyl chloride electrolyte: the same as in Example 1.

[0142] (2) Preparation of carbon cathode sheet: A certain amount of acetylene black nanoparticles and polytetrafluoroethylene emulsion binder (mass ratio 9:1) were weighed, and a certain amount of ethanol was added. The mixture was ultrasonically treated until the carbon particles were uniformly dispersed in the ethanol to obtain carbon slurry. Impurities on the surface of the nickel foam were removed, and the mixture was rinsed with deionized water and ethanol in sequence, and dried in a drying oven at 80°C for 1 hour. The dried nickel foam was placed on a hot plate at 80°C, and the prepared carbon slurry was dropped onto the nickel foam. The solvent in the carbon slurry added in the previous drop was evaporated before the carbon slurry was added again, until the carbon material loading met the expectation (the acetylene black loading in the nickel foam loaded with carbon material obtained in this embodiment was 1-2 mg / cm³). 2 The completely dried electrode sheet is compacted to obtain a carbon positive electrode sheet.

[0143] (3) Preparation of negative electrode: Same as in Example 1.

[0144] (4) Battery assembly: Same as in Example 1.

[0145] Using magnesium foil as the negative electrode, 0.8 mol L -1 Magnesium chloride / thionyl chloride and 2 mol L -1 A magnesium / thionyl chloride primary battery, prepared using aluminum chloride / thionyl chloride as the electrolyte, underwent discharge performance testing. The discharge current was 100 mA g. -1 The discharge cutoff voltage is 0.01V vs. Mg. The battery discharge curve is as follows. Figure 9 As shown, the average discharge voltage plateau is 1.5V, and the discharge specific capacity is 6737mAh g. -1 .

[0146] Example 8

[0147] This embodiment provides a method for preparing a magnesium / thionyl chloride primary battery, including the following steps:

[0148] (1) Preparation of thionyl chloride electrolyte: Same as in Example 1.

[0149] (2) Preparation of carbon positive electrode sheet: A certain amount of flake graphite and polytetrafluoroethylene emulsion binder (mass ratio of 9:1) were weighed, a certain amount of ethanol was added, and the mixture was ultrasonically treated until the carbon particles were uniformly dispersed in the ethanol to obtain a carbon slurry. The surface impurities of the foamed nickel were removed and washed with deionized water and ethanol in turn, and dried in a drying oven at 80°C for 1 hour. The dried foamed nickel was placed on a hot stage at a temperature of 80°C, and the prepared carbon slurry was dropped onto the foamed nickel. After the solvent in the carbon slurry dropped in the previous time was evaporated, the carbon slurry was added again until the loading amount of the carbon material obtained met the expectation (in the foamed nickel loaded with carbon material obtained in this example, the loading amount of flake graphite was 1-2 mg / cm 2 ). The completely dried electrode sheet was compacted to obtain a carbon positive electrode sheet.

[0150] (3) Preparation of negative electrode sheet: The same as the method of Example 1.

[0151] (4) Assembly of battery: The same as the method of Example 1.

[0152] A magnesium / thionyl chloride primary battery was prepared with a magnesium foil as the negative electrode, 0.8 mol L -1 of magnesium chloride / thionyl chloride and 2 mol L -1 of aluminum chloride / thionyl chloride as the electrolyte, and the discharge performance of the battery was tested. The discharge current was 100 mA g -1 , and the discharge cut-off voltage was 0.01 V vs. Mg. The battery discharge curve is shown in Figure 10 , the average discharge voltage plateau was 1.35 V, and the specific discharge capacity was 4252 mAh g -1 .

[0153] Example 9

[0154] The present example provides a preparation method of a magnesium / thionyl chloride primary battery, comprising the following steps:

[0155] (1) Preparation of thionyl chloride electrolyte: In an argon-filled glove box, aluminum chloride was weighed, thionyl chloride was added, the concentration of aluminum chloride was 1 mol L -1 , and it was placed on a magnetic stirrer for sufficient stirring to ensure that the solid was fully dissolved in thionyl chloride. 0.4 mol L -1 of magnesium chloride was added to the above electrolyte to obtain a low-concentration electrolyte containing magnesium chloride.

[0156] The steps (2)-(4) are the same as those of Example 1.

[0157] The magnesium / thionyl chloride primary battery prepared in this example was tested for battery discharge performance, with a discharge current of 100 mA g -1 and a discharge cut-off voltage of 0.01 V vs. Mg. The test resultsFigure 11 As shown (in the image): the average discharge voltage plateau is 1.50V, and the discharge specific capacity is 4193mAh g. -1 .

[0158] Example 10

[0159] This embodiment provides a method for preparing a magnesium / thionyl chloride primary battery, including the following steps:

[0160] (1) Preparation of thionyl chloride electrolyte: Weigh aluminum chloride in a glove box filled with argon atmosphere, add thionyl chloride to it, and the concentration of aluminum chloride is 3 mol / L. -1 Place the mixture on a magnetic stirrer and stir thoroughly to ensure the solid is fully dissolved in thionyl chloride. Then add 1.2 mol L to the electrolyte. -1 Magnesium chloride is used to obtain a high-concentration electrolyte containing magnesium chloride.

[0161] Steps (2)-(4) are the same as in Example 1.

[0162] The magnesium / thionyl chloride primary battery prepared in this embodiment was subjected to battery discharge performance testing, with a discharge current of 100 mA g. -1 The discharge cutoff voltage is 0.01V vs. Mg. Test results ( Figure 12 As shown (in the image): the average discharge voltage plateau is 1.58V, and the discharge specific capacity is 7962mAh g. -1 .

[0163] Example 11

[0164] This embodiment provides a method for preparing a magnesium / thionyl chloride primary battery, including the following steps:

[0165] (1) Preparation of thionyl chloride electrolyte: Weigh aluminum chloride in a glove box filled with argon atmosphere, add thionyl chloride to it, and the concentration of aluminum chloride is 2 mol / L. -1 Place the mixture on a magnetic stirrer and stir thoroughly to ensure the solid is fully dissolved in thionyl chloride. Then add 0.4 mol L to the electrolyte. -1 Magnesium chloride is used to obtain a low-concentration electrolyte containing magnesium chloride.

[0166] Steps (2)-(4) are the same as in Example 1.

[0167] The magnesium / thionyl chloride primary battery prepared in this embodiment was subjected to battery discharge performance testing, with a discharge current of 100 mA g. -1 The discharge cutoff voltage is 0.01V vs. Mg. Test results ( Figure 13 As shown (in the image): the average discharge voltage plateau is 1.60V, and the discharge specific capacity is 8398mAh g. -1.

[0168] Example 12

[0169] This embodiment provides a method for preparing a magnesium / thionyl chloride primary battery, including the following steps:

[0170] (1) Preparation of thionyl chloride electrolyte: Weigh aluminum chloride in a glove box filled with argon atmosphere, add thionyl chloride to it, and the concentration of aluminum chloride is 2 mol / L. -1 Place the mixture on a magnetic stirrer and stir thoroughly to ensure the solid is fully dissolved in thionyl chloride. Then add 0.6 mol L to the electrolyte. -1 Magnesium chloride is used to obtain a low-concentration electrolyte containing magnesium chloride.

[0171] Steps (2)-(4) are the same as in Example 1.

[0172] The magnesium / thionyl chloride primary battery prepared in this embodiment was subjected to battery discharge performance testing, with a discharge current of 100 mA g. -1 The discharge cutoff voltage is 0.01V vs. Mg. Test results ( Figure 14 As shown (in the image): the average discharge voltage plateau is 1.58V, and the discharge specific capacity is 9176mAh g. -1 .

[0173] Applications of the magnesium / thionyl chloride primary battery prepared by this invention: such as Figure 17 As shown, the magnesium / thionyl chloride primary battery prepared by this invention can be applied to smart glasses, light-emitting diodes, electronic watches, etc. Figure 17 a) It can power an electronic watch in both air and water. Figure 17 b and Figure 17 c), and driving 37 light-emitting diodes, driving smart glasses ( Figure 17 d and Figure 17 e), which has very good practicality.

[0174] This invention has many specific applications, and the above description is only a preferred embodiment. It should be noted that the above embodiments are for illustrative purposes only and are not intended to limit the scope of protection of this invention. For those skilled in the art, several improvements can be made without departing from the principle of this invention, and these improvements should also be considered within the scope of protection of this invention.

Claims

1. A magnesium / thionyl chloride primary battery, characterized in that, Includes positive electrode, negative electrode, and electrolyte; The positive electrode is a metallic material loaded with carbon material; The negative electrode sheet is a magnesium foil or a magnesium alloy foil; The electrolyte is a solvent of thionyl chloride and a solute of a metal chloride; the concentration of the metal chloride in the electrolyte is 1-5 mol / L. -1 The metal chloride comprises compounds with a concentration of 1-3 mol / L. -1 Aluminum chloride with a concentration of 0.4-1.2 mol / L -1 Magnesium chloride; The method for preparing the positive electrode sheet includes the following steps: (a) Preparation of carbon slurry: Weigh a certain amount of carbon material particles and binder, add solvent, and ultrasonically treat or grind the resulting mixture until the carbon material particles are uniformly dispersed in the solvent to obtain carbon slurry; (b) Preparation of positive electrode sheet: The prepared carbon slurry is dropped or coated onto the metal material, then dried and compacted to obtain the positive electrode sheet; In step (a), the binder comprises polytetrafluoroethylene emulsion; the solvent comprises ethanol and N-methylpyrrolidone; the mass ratio of the carbon material particles to the binder is 9:1; in step (b), the carbon material loading is 0.1-3 mg / cm³. 2 .

2. The magnesium / thionyl chloride primary battery according to claim 1, characterized in that, The carbon material includes any one of graphite, conductive carbon black, carbon nanotubes, or graphene. The metallic material is selected from either nickel foam or stainless steel foil.

3. The magnesium / thionyl chloride primary battery according to claim 2, characterized in that, The conductive carbon black includes either acetylene black or Ketjen black.

4. The magnesium / thionyl chloride primary battery according to claim 1, characterized in that, The magnesium / thionyl chloride primary battery further includes a negative electrode shell, a gasket, a spring, a separator for loading electrolyte, and a positive electrode shell; the positive electrode shell and the negative electrode shell are sealed together; wherein, the spring, the gasket, and the negative electrode are sequentially disposed in the negative electrode shell, the positive electrode is disposed in the positive electrode shell, and the separator for loading electrolyte is disposed between the positive electrode and the negative electrode.

5. A method for preparing a magnesium / thionyl chloride primary battery according to any one of claims 1-4, characterized in that, Includes the following steps: A. Prepare the positive and negative electrode sheets; prepare the electrolyte; B. Place the spring and gasket in the negative electrode shell in sequence, then place the negative electrode and separator on the gasket in sequence, then inject electrolyte into the separator, then place the positive electrode, and seal with the positive electrode shell to obtain a magnesium / thionyl chloride primary battery.

6. A method for recycling a magnesium / thionyl chloride primary battery according to any one of claims 1-4, characterized in that, Includes the following steps: After the magnesium / thionyl chloride primary battery is discharged, the resulting positive and negative electrode sheets are cleaned and dried to obtain the recovered positive and negative electrode sheets.

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