CN117638122A - Water system magnesium/graphite fluoride primary cell based on salt-packed water electrolyte - Google Patents
Water system magnesium/graphite fluoride primary cell based on salt-packed water electrolyte Download PDFInfo
- Publication number
- CN117638122A CN117638122A CN202311608486.2A CN202311608486A CN117638122A CN 117638122 A CN117638122 A CN 117638122A CN 202311608486 A CN202311608486 A CN 202311608486A CN 117638122 A CN117638122 A CN 117638122A
- Authority
- CN
- China
- Prior art keywords
- electrolyte
- salt
- water
- graphite fluoride
- metal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000003792 electrolyte Substances 0.000 title claims abstract description 114
- QLOAVXSYZAJECW-UHFFFAOYSA-N methane;molecular fluorine Chemical compound C.FF QLOAVXSYZAJECW-UHFFFAOYSA-N 0.000 title claims abstract description 89
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 69
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 title claims abstract description 55
- 239000011777 magnesium Substances 0.000 title claims abstract description 51
- 229910052749 magnesium Inorganic materials 0.000 title claims abstract description 51
- 229910052751 metal Inorganic materials 0.000 claims abstract description 50
- 239000002184 metal Substances 0.000 claims abstract description 50
- 150000003839 salts Chemical class 0.000 claims abstract description 44
- 239000002904 solvent Substances 0.000 claims abstract description 13
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 claims abstract description 5
- 229910001960 metal nitrate Inorganic materials 0.000 claims abstract description 5
- SCVFZCLFOSHCOH-UHFFFAOYSA-M potassium acetate Chemical group [K+].CC([O-])=O SCVFZCLFOSHCOH-UHFFFAOYSA-M 0.000 claims description 68
- 235000011056 potassium acetate Nutrition 0.000 claims description 34
- 238000000034 method Methods 0.000 claims description 21
- XIXADJRWDQXREU-UHFFFAOYSA-M lithium acetate Chemical compound [Li+].CC([O-])=O XIXADJRWDQXREU-UHFFFAOYSA-M 0.000 claims description 18
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 17
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 10
- 239000011888 foil Substances 0.000 claims description 10
- VMHLLURERBWHNL-UHFFFAOYSA-M Sodium acetate Chemical compound [Na+].CC([O-])=O VMHLLURERBWHNL-UHFFFAOYSA-M 0.000 claims description 9
- 239000001632 sodium acetate Substances 0.000 claims description 9
- 235000017281 sodium acetate Nutrition 0.000 claims description 9
- 239000006258 conductive agent Substances 0.000 claims description 8
- 229910002804 graphite Inorganic materials 0.000 claims description 7
- 239000010439 graphite Substances 0.000 claims description 7
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 claims description 6
- 239000011230 binding agent Substances 0.000 claims description 6
- 229910052782 aluminium Inorganic materials 0.000 claims description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 5
- 239000002033 PVDF binder Substances 0.000 claims description 4
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 4
- INHCSSUBVCNVSK-UHFFFAOYSA-L lithium sulfate Inorganic materials [Li+].[Li+].[O-]S([O-])(=O)=O INHCSSUBVCNVSK-UHFFFAOYSA-L 0.000 claims description 4
- RBTVSNLYYIMMKS-UHFFFAOYSA-N tert-butyl 3-aminoazetidine-1-carboxylate;hydrochloride Chemical compound Cl.CC(C)(C)OC(=O)N1CC(N)C1 RBTVSNLYYIMMKS-UHFFFAOYSA-N 0.000 claims description 4
- 239000006245 Carbon black Super-P Substances 0.000 claims description 3
- 239000011149 active material Substances 0.000 claims description 3
- 239000002041 carbon nanotube Substances 0.000 claims description 3
- 229910021393 carbon nanotube Inorganic materials 0.000 claims description 3
- 229910021389 graphene Inorganic materials 0.000 claims description 3
- 229920001343 polytetrafluoroethylene Polymers 0.000 claims description 3
- 239000004810 polytetrafluoroethylene Substances 0.000 claims description 3
- 229920002981 polyvinylidene fluoride Polymers 0.000 claims description 3
- 239000006230 acetylene black Substances 0.000 claims description 2
- 239000003273 ketjen black Substances 0.000 claims description 2
- 229910001092 metal group alloy Inorganic materials 0.000 claims description 2
- -1 polytetrafluoroethylene Polymers 0.000 claims description 2
- 239000010406 cathode material Substances 0.000 claims 1
- 239000000126 substance Substances 0.000 abstract description 5
- 239000010405 anode material Substances 0.000 abstract description 4
- 230000000052 comparative effect Effects 0.000 description 34
- 238000004090 dissolution Methods 0.000 description 10
- 238000002360 preparation method Methods 0.000 description 10
- 238000012360 testing method Methods 0.000 description 8
- 238000013461 design Methods 0.000 description 7
- 238000007086 side reaction Methods 0.000 description 7
- 239000011701 zinc Substances 0.000 description 7
- 229910052725 zinc Inorganic materials 0.000 description 7
- 238000007599 discharging Methods 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 4
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 229910052744 lithium Inorganic materials 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 238000006115 defluorination reaction Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- NBVXSUQYWXRMNV-UHFFFAOYSA-N fluoromethane Chemical compound FC NBVXSUQYWXRMNV-UHFFFAOYSA-N 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000005486 organic electrolyte Substances 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 238000000227 grinding Methods 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000005457 optimization Methods 0.000 description 2
- 239000007774 positive electrode material Substances 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 230000000087 stabilizing effect Effects 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 235000000405 Pinus densiflora Nutrition 0.000 description 1
- 240000008670 Pinus densiflora Species 0.000 description 1
- 239000013543 active substance Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 239000008367 deionised water Substances 0.000 description 1
- 229910021641 deionized water Inorganic materials 0.000 description 1
- 238000006056 electrooxidation reaction Methods 0.000 description 1
- 238000003682 fluorination reaction Methods 0.000 description 1
- 239000003365 glass fiber Substances 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- WJZHMLNIAZSFDO-UHFFFAOYSA-N manganese zinc Chemical compound [Mn].[Zn] WJZHMLNIAZSFDO-UHFFFAOYSA-N 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000012216 screening Methods 0.000 description 1
- BSWGGJHLVUUXTL-UHFFFAOYSA-N silver zinc Chemical compound [Zn].[Ag] BSWGGJHLVUUXTL-UHFFFAOYSA-N 0.000 description 1
- 238000007614 solvation Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 229910021642 ultra pure water Inorganic materials 0.000 description 1
- 239000012498 ultrapure water Substances 0.000 description 1
Landscapes
- Primary Cells (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention provides a water-based graphite fluoride primary cell based on a salt-packed water electrolyte, which is characterized in that the positive electrode of the water-based magnesium/graphite fluoride primary cell based on the salt-packed water electrolyte is graphite fluoride, and the negative electrode of the water-based magnesium/graphite fluoride primary cell is magnesium metal; the electrolyte comprises solvent water and electrolyte salt, wherein the electrolyte salt comprises any one of metal acetate or metal nitrate, and the molar concentration of the metal acetate or the metal nitrate in the electrolyte is 20-33mol/kg. The aqueous graphite fluoride battery electrolyte provided by the invention not only can solve the problem of interface compatibility with a graphite fluoride anode material, but also can maintain chemical stability when an active metal anode is discharged, so that self-discharge is reduced. The specific capacity and voltage of the water-based metal/graphite fluoride primary battery based on the water-in-salt electrolyte are greatly improved, so that the high specific energy water-based graphite fluoride primary battery is realized. The aqueous graphite fluoride primary cell based on the water-in-salt electrolyte has the advantages of high energy density, safety, stable output voltage and the like.
Description
Technical Field
The invention belongs to the technical field of battery materials, and relates to a metal/water system graphite fluoride primary battery based on a salt-packed water electrolyte.
Background
Lithium/graphite fluoride battery (Li/CF) x ) Is the first commercial organic electrolyte lithium primary battery (non-rechargeable) produced by the japanese pine electric company and has wide application in military, electronic, medical, space applications or other extreme environments. Li/CF x The primary cell typically uses Li metal as the negative electrode, CF x The positive electrode is an electrolyte, and the salt dissolved in the organic solvent is an electrolyte. The discharge process is a conversion reactionCF x The conductive carbon is converted into conductive carbon, so that the conductivity of the primary battery can be increased, and the stability of the discharge voltage and the discharge efficiency of the primary battery are improved. Thus, in comparison to conventional zinc manganese, silver zinc chemical power supplies, in organic electrolytes, li/CF x The primary cell has high specific mass capacity of 0.86Ah/g, high theoretical specific mass energy (2180 Wh/kg) and high open circuit voltage>2.5V) and a smooth discharge platform. Furthermore, CF x The structure of the material ensures that the material has good stability, so Li/CF x Also shows smaller self-discharge rate and longer storage life>10 years).
Compared with the prior CF x The high-cost and inflammable organic electrolyte used by the primary battery has the characteristics of higher ion transmission capability, low cost and strong safety, and reports on the aqueous electrolyte system are rare, and the aqueous electrolyte system cannot be practically applied to CF at present x In the galvanic cell. In one aspect, CF x Has low surface energy, and has interface compatibility problem with the positive electrode, so in the conventional aqueous solution, CF x Positive electrode CF of primary cell x The defluorination process is limited, resulting in incomplete discharge; on the other hand, metal anodes (e.g., lithium, magnesium, zinc, etc.) are particularly active, resulting in more side reactions and even dissolution in conventional aqueous solutions, and thus the discharge process voltage becomes extremely unstable. Both of these factors are limiting the water system CF x The practical application of the primary battery is critical.
Based on the above, it is an urgent problem to be solved at present to find an inexpensive high specific energy metal/graphite fluoride primary cell aqueous electrolyte which can enhance the interface compatibility with the graphite fluoride positive electrode material and can also improve the stability of the metal negative electrode in the aqueous electrolyte. Meanwhile, because the natural abundance of lithium resources is very limited (about 0.0017 wt.%), other efficient metal cathodes are also urgently needed to be searched.
CN102903921a discloses a fluorocarbon battery based on an aqueous electrolyte, indicating the possibility of an aqueous graphite fluoride battery. However, in the prior art, the water system CF x Research on primary batteries has not yet progressed.
Disclosure of Invention
In view of the shortcomings of the prior art, the invention aims to provide an aqueous metal/graphite fluoride primary cell based on a water-in-salt electrolyte.
To achieve the purpose, the invention adopts the following technical scheme:
in one aspect, the invention provides a water-in-salt graphite fluoride battery electrolyte comprising solvent water and an electrolyte salt comprising any one of a metal acetate or a metal nitrate salt in a molar concentration of 20-33mol/kg (e.g., 20mol/kg, 24mol/kg, 25mol/kg, 27mol/kg, 29mol/kg, 30mol/kg, or 33 mol/kg) in the electrolyte.
In the invention, the electrolyte has interface compatibility with graphite fluoride anode materials and has a function of protecting a metal anode.
The invention provides the water-in-salt electrolyte, which not only can solve the problem of interface compatibility with the graphite fluoride anode material, but also can ensure that the active metal anode keeps chemical stability in the discharging process, and further improves the specific capacity, voltage and other performances of the graphite fluoride primary battery.
In the invention, if the molar concentration of the electrolyte salt in the electrolyte is lower than 20mol/kg, side reaction occurs to the metal negative electrode, self discharge exists, the discharge of the metal/graphite fluoride aqueous battery is unstable, the battery can not be used for high-efficiency continuous stable voltage output, the operation of the aqueous graphite fluoride primary battery can not be realized, and if the molar concentration is higher than 33mol/kg, the electrolyte is easy to saturate and precipitate.
The electrolyte of the invention does not contain any additive.
The electrolyte salts also include other soluble metal salts;
preferably, the other soluble metal salt comprises any one or a combination of at least two of a brominated metal salt or a sulfuric acid metal salt;
preferably, the other soluble metal salt comprises at least one of lithium acetate, sodium acetate or lithium sulfate.
Preferably, the molar concentration of the other soluble metal salt in the electrolyte is 1-3mol/kg, for example 1mol/kg, 1.3mol/kg, 1.5mol/kg, 1.8mol/kg, 2mol/kg, 2.3mol/kg, 2.5mol/kg, 2.8mol/kg or 3mol/kg.
Preferably, the electrolyte salt is potassium acetate, or a combination of potassium acetate and lithium acetate or sodium acetate.
In the present invention, in the combination of potassium acetate and lithium acetate or sodium acetate, the potassium acetate is at a high concentration, and the lithium acetate or sodium acetate is at a low concentration.
Preferably, the solvent water is selected from deionized water or ultrapure water.
In another aspect, the invention provides a method for preparing the water-in-salt graphite fluoride battery electrolyte, which comprises the following steps:
and adding electrolyte salt into solvent water, and fully dissolving to obtain the water-in-salt graphite fluoride battery electrolyte.
In another aspect, the present invention provides an aqueous metal/graphite fluoride cell based on a salt-coated aqueous electrolyte comprising a positive electrode, a negative electrode, and a salt-coated aqueous graphite fluoride cell electrolyte as described above.
Preferably, the positive electrode is made of an active material CF x Powder, conductive agent and binder, mainly used for CF x The conversion reaction realizes charge transfer; the positive electrode active material may be a commercial CF x (x=0.85-1.1) powder, and the conductive agent is graphene, ketjen black or acetyleneBlack, carbon nanotubes, super-P, or a combination of at least two, the binder is polyvinylidene fluoride (PVDF) and/or Polytetrafluoroethylene (PTFE).
In one possible implementation, there is provided an aqueous magnesium/graphite fluoride primary cell based on a salt-packed aqueous electrolyte, the positive electrode of the aqueous magnesium/graphite fluoride primary cell being CF x The cathode is magnesium foil, wherein the anode plate is mixed in an agate grinding pot according to the proportion of active material, conductive agent and binder of 6:3:1, and is ground and pulped by using N-methyl pyrrolidone (NMP). And (3) coating the uniformly ground slurry on a current collector, and placing the current collector in a vacuum oven to dry for 20 hours at 100 ℃ to obtain the positive electrode plate.
Preferably, the current collector may be any one of aluminum foil, copper mesh, titanium mesh or titanium sheet, etc.
Preferably, the negative electrode adopts magnesium foil, zinc foil, aluminum foil or corresponding metal alloy and the like.
Compared with the prior art, the invention has the following beneficial effects:
the electrolyte of the water-in-salt graphite fluoride battery can solve the problem of interface compatibility with a graphite fluoride anode material, can keep chemical stability when an active metal anode is discharged, further improves the specific capacity and voltage of the water-based graphite fluoride primary battery, and realizes the high specific energy water-based graphite fluoride primary battery. The graphite fluoride primary cell has the advantages of high energy density, safety, stable output voltage and the like.
Drawings
FIG. 1 is a schematic diagram of the structure of an aqueous magnesium/graphite fluoride primary cell based on a water-in-salt electrolyte according to the present invention;
FIG. 2A is a state diagram of the electrolyte of example 1 of the present invention;
FIG. 2B is the constant current discharge performance of the aqueous magnesium/graphite fluoride primary cell of example 1 of the present invention;
FIGS. 3-5 are graphs showing constant current discharge performance of the aqueous magnesium/graphite fluoride cells of example 2 of the present invention at different current densities;
FIG. 6 is a graph showing the constant current discharge performance of the aqueous magnesium/graphite fluoride primary cell of example 3 of the present invention;
FIG. 7 is a graph showing the constant current discharge performance of the aqueous magnesium/graphite fluoride primary cell device of example 5 of the present invention;
FIG. 8 is a graph showing the constant current discharge performance of the aqueous zinc/graphite fluoride primary cell of example 6 of the present invention;
FIG. 9 is a graph showing the constant current discharge performance of the aqueous magnesium/graphite fluoride primary cell of comparative example 1 of the present invention;
FIG. 10 is a graph showing the constant current discharge performance of the aqueous magnesium/graphite fluoride primary cell of comparative example 2 of the present invention;
fig. 11 shows the constant current discharge performance of the aqueous magnesium/graphite fluoride primary cell of comparative example 3 of the present invention.
Detailed Description
The technical scheme of the invention is further described by the following specific embodiments. It will be apparent to those skilled in the art that the examples are merely to aid in understanding the invention and are not to be construed as a specific limitation thereof.
Example 1
The embodiment provides a water-in-salt graphite fluoride battery electrolyte, which comprises solvent water and potassium acetate, wherein the concentration of the potassium acetate is 30mol/kg.
The preparation of the aqueous magnesium/graphite fluoride galvanic cell based on the water-in-salt electrolyte is as follows: the active substance CF x Powder, graphene as a conductive agent, carbon nanotubes as a conductive agent, super-P as a conductive agent and PVDF (polyvinylidene fluoride) as a binder are mixed in an agate grinding bowl according to a mass ratio of 6:1:1:1:1, and are ground and pulped by using NMP (N-methylpyrrolidone). And (3) coating the uniformly ground slurry on a plurality of aluminum foil current collectors, and placing the aluminum foil current collectors in a vacuum oven to dry for 20 hours at the temperature of 100 ℃ to obtain the positive electrode plate.
And adding 2.94g of potassium acetate into 1g of water for sufficient ultrasonic dissolution to obtain the salt-package water electrolyte provided in the embodiment 1 of the invention. By CF x And adding the electrolyte into a magnesium foil with the thickness of 0.1mm serving as a cathode to assemble the water-based magnesium/graphite fluoride primary battery, wherein the structural schematic diagram of the battery is shown in figure 1.
The electrolyte in this example exhibited a clear transparent state as shown in fig. 2A.
The aqueous magnesium/graphite fluoride primary cell of this example was subjected to a two-electrode discharge performance test at a constant current of 0.1C, and the test results are shown in fig. 2B, and as can be seen from fig. 2B, the discharge voltage plateau is as high as 0.93V at a current density of 0.1C, and the specific capacity is close to 800mAh/g. By increasing the salt concentration, the preparation of the salt-coated water electrolyte system can obviously improve the solvent coating structure and chemical composition in the electrolyte, and is more beneficial to the improvement of the discharge performance of the water-based magnesium/graphite fluoride primary battery.
Example 2
The embodiment provides a water-in-salt graphite fluoride battery electrolyte, which comprises solvent water, potassium acetate and lithium acetate, wherein the concentration of the potassium acetate is 30mol/kg, and the concentration of the lithium acetate is 3mol/kg.
The preparation of the aqueous magnesium/graphite fluoride galvanic cell based on the water-in-salt electrolyte is as follows: the present example provides a water-based magnesium/graphite fluoride primary cell, and the positive electrode sheet manufacturing process was the same as described in example 1. Adding 2.94g of potassium acetate and 0.198g of lithium acetate into 1g of water for sufficient ultrasonic dissolution to obtain the salt-covered water electrolyte provided in the embodiment 1 of the invention. In accordance with the procedure of example 1, a water-based magnesium/graphite fluoride primary cell was assembled, and the discharge results of the two electrode test at different current densities are shown in fig. 3-5. The electrochemical performance of the aqueous graphite fluoride primary cell can be further improved by adjusting and controlling the components of the electrolyte to introduce additional low-concentration soluble metal salt components, wherein the lithium acetate and the high-concentration potassium acetate are optimally combined by screening the types of the low-concentration soluble metal salts.
Example 3
The embodiment provides a water-in-salt graphite fluoride battery electrolyte, which comprises solvent water, potassium acetate and sodium acetate, wherein the concentration of the potassium acetate is 30mol/kg, and the concentration of the sodium acetate is 3mol/kg.
The preparation of the aqueous magnesium/graphite fluoride galvanic cell based on the water-in-salt electrolyte is as follows: the present example provides a water-based magnesium/graphite fluoride primary cell, and the positive electrode sheet manufacturing process was the same as described in example 1. Adding 2.94g of potassium acetate and 0.246g of sodium acetate into 1g of water for sufficient ultrasonic dissolution to obtain the salt-covered water electrolyte provided in the embodiment 1 of the invention. In accordance with the manufacturing process of example 1, the aqueous magnesium/graphite fluoride primary cell was assembled, and the results of the two-electrode constant current discharge test are shown in fig. 6.
Example 4
The embodiment provides a water-in-salt graphite fluoride battery electrolyte, which comprises solvent water and potassium acetate, wherein the concentration of the potassium acetate is 30mol/kg, and the concentration of lithium sulfate is 1mol/kg.
The preparation of the aqueous magnesium/graphite fluoride galvanic cell based on the water-in-salt electrolyte is as follows: the present example provides a water-based magnesium/graphite fluoride primary cell, and the positive electrode sheet manufacturing process was the same as described in example 1. Adding 2.94g of potassium acetate and 0.110g of lithium sulfate into 1g of water for sufficient ultrasonic dissolution to obtain the salt-covered water electrolyte provided in the embodiment 1 of the invention. In accordance with the procedure of example 1, a water-based magnesium/graphite fluoride primary cell was assembled, which had a discharge voltage plateau of up to 0.83V at a current density of 0.5C and a specific capacity of approximately 807mAh/g.
Example 5
The embodiment provides a water-in-salt graphite fluoride battery electrolyte and a magnesium/graphite fluoride primary battery device, which comprise solvent water, potassium acetate and lithium acetate, wherein the concentration of the potassium acetate is 30mol/kg, and the concentration of the lithium acetate is 3mol/kg.
The preparation of the aqueous magnesium/graphite fluoride galvanic cell based on the water-in-salt electrolyte is as follows: in view of the application under practical conditions, this embodiment also provides a water-based magnesium/graphite fluoride primary battery device, which is consistent with the manufacturing process of the positive electrode sheet and the electrolyte described in embodiment 1. By CF x The method is characterized in that a magnesium foil with the size of 2cm x 2cm is used as a cathode, a glass fiber diaphragm is added between the cathode and the anode, and meanwhile, a sufficient amount of prepared electrolyte is added to construct a soft package battery device. The assembled device is subjected to a two-electrode constant-current discharge test in the salt-coated water electrolyte, and the result is shown in figure 7, wherein the discharge specific capacity of the water-based magnesium/graphite fluoride primary battery device is about 700mAh/g under the current density of 0.1C, and the discharge voltage platform is close to 1V. This good performing device design illustrates the salt water-in-package based aspects of the present inventionThe electrolyte has practical application value in the aqueous graphite fluoride battery.
Example 6
The embodiment provides a water-in-salt graphite fluoride battery electrolyte and is applied to a water-based zinc/graphite fluoride primary battery, and the water-based zinc/graphite fluoride battery electrolyte comprises solvent water, potassium acetate and lithium acetate, wherein the concentration of the potassium acetate is 30mol/kg, and the concentration of the lithium acetate is 3mol/kg.
The preparation of the aqueous zinc/graphite fluoride primary cell based on the water-in-salt electrolyte is as follows: the embodiment additionally provides a water-based graphite fluoride primary battery with other metal cathodes, and the manufacturing process of the positive electrode plate and the electrolyte is the same as that described in the embodiment 1. By CF x And the water-based zinc/graphite fluoride primary battery is assembled by adding the salt-coated water electrolyte into the positive electrode and the zinc foil serving as the negative electrode, and the constant-current discharge test results of the two electrodes are shown in figure 8. The specific discharge capacity of the water-based zinc/graphite fluoride primary battery device is about 800mAh/g under the current density of 0.1C, and further illustrates that the water-in-salt electrolyte based on the design of the invention has application potential in different metal/graphite fluoride primary batteries.
Comparative example 1
The procedure for the preparation of the positive electrode of the aqueous magnesium/graphite fluoride primary cell of this comparative example was the same as that described in example 1. The electrolyte provided in comparative example 1 had a potassium acetate concentration of 5mol/kg: the aqueous magnesium/graphite fluoride primary cell was assembled with reference to example 1 by adding 0.49g of potassium acetate to 1g of water for sufficient ultrasonic dissolution, and the results and key parameters of the two-electrode constant current discharge test of the aqueous magnesium/graphite fluoride primary cell described in comparative example 1 are shown in fig. 9. The reason for the unstable discharge voltage of the graphite fluoride battery is found to be a large number of bubbles caused by side reaction, meanwhile, the metal negative electrode is dissolved, the short circuit of the primary battery is easily caused, and potential safety hazards are caused. During dissolution of the negative electrode, the positive electrode also transmits electrons, thereby causing side reactions during discharge to cause partial capacity of the additional defluorination process of the non-fluorinated graphite.
Comparative example 2
The procedure for the preparation of the positive electrode of the aqueous magnesium/graphite fluoride primary cell of this comparative example was the same as that described in example 1. The electrolyte provided in comparative example 2 had a potassium acetate concentration of 15mol/kg: 1.47g of potassium acetate was added to 1g of water for sufficient ultrasonic dissolution, and an aqueous magnesium/graphite fluoride primary cell was assembled with reference to example 1, and the results of the two-electrode constant current discharge test and key parameters are shown in fig. 10. By observing the electrolyte phenomenon in the discharging process of the comparative example 2, compared with the comparative example 1, the electrolyte is found that after the concentration of the electrolyte is increased in the comparative example 2, more bubbles exist in the discharging process of the graphite fluoride battery in the discharging process, but the short circuit of the primary battery is not caused, so that the design of the electrolyte is beneficial to the operation of the metal/graphite fluoride water-based primary battery.
Comparative example 3
The procedure for the preparation of the positive electrode of the aqueous magnesium/graphite fluoride primary cell of this comparative example was the same as that described in example 1. The electrolyte provided in comparative example 1 had a potassium acetate concentration of 15mol/kg and a lithium acetate concentration of 1mol/kg: 1.47g of potassium acetate and 0.066g of lithium acetate were added to 1g of water and sufficiently dissolved by ultrasonic waves, and an aqueous magnesium/graphite fluoride primary cell was assembled with reference to example 1. Comparative example 3, example 1 and example 2 were compared with each other for discharge performance of the primary batteries of water-based magnesium/graphite fluoride, and the results of the constant current discharge test of two electrodes and key parameters are shown in fig. 11. The aqueous magnesium/graphite fluoride primary cell described in comparative example 1, which has a discharge voltage lower than 0.7V at a current density of 0.5C, is far lower than the voltage plateau of example 1, and the discharge process of comparative example 1 is particularly unstable and bubbles are remarkable during the reaction. Meanwhile, in the comparative examples 1 and 2, after other soluble metal salts are added on the basis of high-concentration potassium acetate, the discharge voltage stability of the magnesium/graphite fluoride water-based battery in operation is greatly improved. Therefore, the design of the salt-coated water electrolyte has remarkable advantages in improving the interface compatibility of the electrolyte and the positive electrode and stabilizing the metal negative electrode, and finally, the primary battery load is stably discharged.
The results of discharging the primary cells in comparative examples 1-2 and example 1 are summarized in table 1.
TABLE 1
| Concentration of electrolyte | Current Density (C) | Average discharge voltage (V) | Discharge capacity (mAh/g) | |
| Comparative example 1 | 5mol/kg KAc | 0.1 | 0.77 | 600 |
| Comparative example 2 | 15mol/kg KAc | 0.1 | 0.89 | 729 |
| Example 1 | 30mol/kg KAc | 0.1 | 0.93 | 800 |
Comparative examples 1-2 and example 1 in table 1 are the discharge results of graphite fluoride aqueous batteries under the electrolyte salt concentration gradient conditions provided by us, respectively. The discharging curve is flat, so that the designed primary battery has stable working voltage, and the battery can be effectively and stably discharged. As can be seen from the discharge curves of comparative examples 1-2, the voltage during discharge of these curves is abrupt or jumped, and is mainly caused by electrochemical corrosion of the metal negative electrode itself during discharge and a large number of bubbles around the metal negative electrode caused by side reactions.
In comparative example 1, the discharge process has extremely many bubbles, which is shown by shaking of the initial discharge process curve (fig. 9), and the final magnesium metal anode is completely dissolved; the discharge bubbles of comparative example 2 are also obvious, the bubbles are accumulated gradually along with the reaction, the discharge capacity starts to shake drastically at 400mAh/g (figure 10), and finally the dissolution rate of the magnesium metal anode can reach 50%. Therefore, when the electrolyte salt concentration is relatively low, the magnesium/graphite fluoride aqueous battery is unstable in discharge due to the influence of bubbles of the magnesium metal negative electrode, and the battery cannot efficiently and stably output voltage, and cannot realize the operation of the high specific energy aqueous graphite fluoride primary battery.
It is particularly emphasized that at relatively low concentrations, there is a large number of metal negative side reactions, and the partial capacities of 600mAh/g in comparative example 1 and 729mAh/g in comparative example 2 are contributions of side reactions during discharge. Therefore, we cannot distinguish the contribution of the capacity of the fluorographite defluorination process from the contribution of the capacity of the metal negative electrode dissolution process, and further illustrate the design necessity of the electrolyte of the water-in-salt fluorographite battery.
By combining comparative examples 1-2 with example 1, when the concentration of electrolyte salt is increased, the salt-coated water electrolyte designed by the invention can solve the problem of interface compatibility with a graphite fluoride positive electrode while ensuring high-efficiency interface ion conduction, can make a metal negative electrode more stable, and reduce self-discharge, thereby ensuring stable working voltage of a water-based primary battery and stabilizing continuous output voltage.
The results of the cell discharge for comparative example 3 and examples 2-6 are summarized in table 2.
TABLE 2
As shown in table 2, we further optimized the water-in-salt electrolyte, and by optimizing the electrolyte composition, the discharge voltage and discharge capacity of the aqueous magnesium/graphite fluoride primary cell were greatly improved compared with example 1. The main mode of electrolyte optimization is to add other soluble metal salts on the basis of high-concentration potassium acetate, and researches show that the high-concentration combined salts in the embodiments 2-5 are more beneficial to adjusting the solvation structure of the electrolyte and improving the environment of the electrolyte. Similar to the results of the comparative examples in table 1, comparative example 3 (fig. 11) is a combination of relatively low concentration potassium acetate and lithium acetate, which is far lower in discharge voltage, discharge capacity than example 2. In connection with all comparative examples, it is necessary to more effectively demonstrate the design of the electrolyte for a graphite cell based on water-in-salt fluorination.
Further, it is preferable that the aqueous magnesium/graphite fluoride primary cell based on the salt-packed aqueous electrolyte in the preferred embodiment 2 (fig. 3 to 5) has a specific discharge capacity exceeding 900mAh/g under a low current density of 0.1C, a discharge voltage plateau of about 1.1V, and a capacity retention rate exceeding 85% under 1C, and shows very excellent performance. As is evident from the comparison of examples 1 and 2, the stability of the discharge voltage of the magnesium/graphite fluoride aqueous battery during operation can be improved by adding other soluble metal salts based on high concentration potassium acetate.
According to the invention, through the design and optimization of the salt-covered water electrolyte, the high and stable discharge working voltage and the excellent discharge capacity are obtained, and the finally prepared aqueous graphite fluoride primary battery can effectively stabilize the output voltage. Meanwhile, the high-concentration potassium acetate and lithium acetate which are optimally proportioned by the salt-packed water electrolyte are combined, and the assembled device realizes the voltage close to 1V and is expected to be practically applied. In addition, in order to enrich the application of the salt water-in-water aqueous electrolyte in the graphite fluoride primary cell, other metal cathodes are explored, and the stable operation of different metal/graphite fluoride aqueous primary cells is realized.
The applicant states that the present invention is illustrated by the above examples for the electrolyte of a water-in-salt graphite fluoride battery and the graphite fluoride battery of the present invention, but the present invention is not limited to the above examples, i.e., it is not meant that the present invention must be practiced by the above examples. It should be apparent to those skilled in the art that any modification of the present invention, equivalent substitution of raw materials for the product of the present invention, addition of auxiliary components, selection of specific modes, etc., falls within the scope of the present invention and the scope of disclosure.
Claims (8)
1. The electrolyte is characterized by comprising solvent water and electrolyte salt, wherein the electrolyte salt comprises any one of metal acetate or metal nitrate, and the molar concentration of the metal acetate or the metal nitrate in the electrolyte is 20-33mol/kg.
2. The water-in-salt graphite fluoride battery electrolyte of claim 1, wherein the electrolyte has interfacial compatibility with graphite fluoride cathode material and protection of metallic negative electrodes.
3. The water-in-salt graphite fluoride battery electrolyte of claim 1, wherein the electrolyte salt further comprises other soluble metal salts;
preferably, the other soluble metal salt comprises any one or a combination of at least two of a brominated metal salt or a sulfuric acid metal salt;
preferably, the other soluble metal salt comprises at least one of lithium acetate, sodium acetate or lithium sulfate.
4. A water-in-salt graphite fluoride battery electrolyte according to claim 1 or 3, wherein the molar concentration of the other soluble metal salt in the electrolyte is 1-3mol/kg.
5. The water-in-salt graphite fluoride battery electrolyte of any one of claims 1-4, wherein the electrolyte salt is potassium acetate, or a combination of potassium acetate and lithium acetate or sodium acetate.
6. The method for preparing a water-in-salt fluorinated graphite battery electrolyte according to any one of claims 1 to 5, comprising the steps of:
and adding electrolyte salt into solvent water, and fully dissolving to obtain the water-in-salt graphite fluoride battery electrolyte.
7. An aqueous metal/graphite fluoride cell based on a salt-covered water electrolyte, characterized in that the aqueous graphite fluoride cell comprises a positive electrode, a negative electrode and the salt-covered water graphite fluoride cell electrolyte of any one of claims 1 to 5;
preferably, the positive electrode is composed of a graphite fluoride active material, a conductive agent, and a binder;
preferably, the conductive agent is one or a combination of at least two of graphene, ketjen black, acetylene black, carbon nanotubes and Super-P;
preferably, the binder is polyvinylidene fluoride and/or polytetrafluoroethylene.
8. The aqueous graphite fluoride primary cell based on a water-in-salt electrolyte according to claim 7, wherein the negative electrode is a magnesium foil, a zinc foil, an aluminum foil or a corresponding metal alloy.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311608486.2A CN117638122A (en) | 2023-11-29 | 2023-11-29 | Water system magnesium/graphite fluoride primary cell based on salt-packed water electrolyte |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311608486.2A CN117638122A (en) | 2023-11-29 | 2023-11-29 | Water system magnesium/graphite fluoride primary cell based on salt-packed water electrolyte |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117638122A true CN117638122A (en) | 2024-03-01 |
Family
ID=90029861
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311608486.2A Pending CN117638122A (en) | 2023-11-29 | 2023-11-29 | Water system magnesium/graphite fluoride primary cell based on salt-packed water electrolyte |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117638122A (en) |
-
2023
- 2023-11-29 CN CN202311608486.2A patent/CN117638122A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11283078B2 (en) | Aqueous slurry for battery electrodes | |
| US9525197B2 (en) | Stable non-aqueous electrolyte promoting ideal reaction process in rechargeable lithium-air batteries | |
| WO2011079482A1 (en) | Battery | |
| WO2017000219A1 (en) | Doped conductive oxide and improved electrochemical energy storage device polar plate based on same | |
| CN107068989B (en) | Positive electrode material for lithium iodine battery | |
| CN111646459A (en) | Preparation method and application of boron-doped graphene material | |
| CN113644326A (en) | Water-based zinc ion battery and formation method | |
| CN113851738B (en) | Rechargeable manganese ion battery and preparation method thereof | |
| CN113823839B (en) | Electrolyte and sodium ion battery containing same | |
| CN114824278A (en) | SEI film reaction liquid, modification method of zinc negative electrode and modified zinc negative electrode | |
| CN1155132C (en) | Non-aqueous electrolyte cell | |
| CN111313023A (en) | High-solid-content semi-solid electrode, preparation method thereof and lithium slurry flow battery comprising electrode | |
| CN117638122A (en) | Water system magnesium/graphite fluoride primary cell based on salt-packed water electrolyte | |
| CN112820940B (en) | Non-aqueous electrolyte containing 2-fluoro-3-pyridineboronic acid, and lithium metal battery containing same | |
| CN213150817U (en) | Copper current collector | |
| CN107464952B (en) | The lithium oxygen battery of electrolyte and its preparation based on N- Methylphenothiazine additive | |
| CN113161603A (en) | Novel potassium ion battery and preparation method thereof | |
| JP2007149533A (en) | Electrode, and electrochemical cell using it | |
| CN113140809B (en) | High-performance rechargeable bromine ion battery based on two-dimensional material MoS2 and preparation method thereof | |
| CN114497539B (en) | Aqueous rechargeable battery based on copper ferrocyanide anode and phenazine organic matter cathode | |
| CN112864459B (en) | Electrolyte, preparation method thereof and secondary lithium metal battery | |
| KR100342050B1 (en) | Composition comprising anode acitve material of lithium secondary battery and lithium secondary battery comprising anode manufactured using the same | |
| CN114899494B (en) | Electrolyte for lithium-sulfur battery and application thereof | |
| US20220190388A1 (en) | Electrolyte for lithium-metal battery having improved stability | |
| US20230130827A1 (en) | Positive electrode slurry for lithium secondary battery, preparation method for same, positive electrode for lithium secondary battery, and lithium secondary battery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |