CN111106352A - Cross-linking type water-based binder for lithium ion battery and electrode prepared from cross-linking type water-based binder - Google Patents
Cross-linking type water-based binder for lithium ion battery and electrode prepared from cross-linking type water-based binder Download PDFInfo
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Abstract
The polymer binder has a three-dimensional network structure and is prepared by in-situ polymerization of at least one of cationic polyacrylamide and a polymer containing carboxyl functional groups or carboxylate functional groups. The polymer binder is crosslinked in situ to form a three-dimensional network structure in the normal-temperature pulping process, can improve the stability of the slurry, particularly the nano slurry, has an effective limiting effect on the volume change of the electrode, and maintains the stability of the electrode structure.
Description
Technical Field
The invention belongs to the technical field of lithium ion battery production, and particularly relates to a cross-linking type water-based binder for a lithium ion battery and an electrode prepared from the same.
Background
The lithium ion battery has the advantages of high specific energy, high working voltage, long cycle life and the like, and is widely applied to the fields of portable electronic products, electric automobiles and the like at present. Further development of high energy density lithium ion batteries puts higher demands on electrode materials. For the lithium ion battery negative electrode material, the graphite negative electrode material is the most widely commercialized material at present, but the theoretical specific capacity of the graphite negative electrode material is only 372mAh/g, and the demand of further development of the lithium ion battery is difficult to meet.
The silicon material is a kind of negative electrode material which is researched more in recent years, and compared with a graphite negative electrode, the silicon material has the following advantages: first, silicon forms Li in the presence of complete lithium intercalation22Si5The specific capacity of the anode material can reach 4200mAh/g, and the anode material is the highest among currently developed anode materials; secondly, silicon has a suitable working voltage (slightly higher than that of graphite materials), so that the silicon has better safety; third, silicon is an element in the earth's crust that is second only to oxygen, has abundant reserves, and is environmentally friendly. Therefore, silicon anode materials have become one of the key materials of the next generation of high energy density lithium ion batteries.
The silicon material generates huge volume expansion (> 300%) in the lithium intercalation/lithium deintercalation process, which causes poor cycling stability of the electrode, and is a problem to be solved urgently in the process of commercial application of the silicon material. At present, most researches start from modification of a material, and stability of the silicon material in a lithium insertion/lithium removal process is improved by nano-converting and compounding the silicon material. Controlling the volume effect of the silicon negative electrode from the binder perspective also improves the cycling stability of the electrode. At present, polyvinylidene fluoride (PVDF) is a common binder used in lithium ion batteries, but since PVDF lacks polar functional groups, effective binding action on silicon materials cannot be formed, and thus, PVDF is difficult to be applied to silicon-based negative electrodes with large volume expansion.
Water-based binders such as sodium carboxymethylcellulose (CMC), sodium alginate (Alg) and polyacrylic acid (PAA) contain polar functional groups such as carboxyl (-COOH) groups in the molecules, and the polar functional groups can generate hydrogen bond interaction with the oxide layer on the surface of the silicon particles. Therefore, the water-based binder can generate a better binding effect on the silicon material, and the cycling stability of the silicon-based negative electrode is obviously improved. Many of the prior art patents have also developed a variety of different water-based binder systems (e.g., patent CN110233265A and patent CN 107170989A). However, these binder molecules are linear and still easily fall off from the surface of the silicon particles when used alone as a binder, resulting in an increase in the irreversible capacity of the silicon-based negative electrode in the latter cycle period.
In order to improve the interaction between the binder and the active material, researchers have devised the composition and structure of the binder, wherein binder systems having a three-dimensional network structure have received extensive attention from the researchers because they can better restrict the movement and separation of the electrode components. Song et al used PAA (polyacrylic acid) and PVA (polyvinyl alcohol) in combination (Advanced Functional materials.2014,24(37): 5904-. In the process of vacuum drying of the electrode, a carboxyl (-COOH) functional group in a PAA molecule and a hydroxyl (-OH) functional group in PVA undergo a dehydration condensation reaction to form a polymer binder network. The binder with the cross-linked structure can limit the structural change of the electrode and improve the cycling stability of the electrode. Lim et al constructed self-healing cross-linked binders (ACS Applied Materials & interfaces.2015,7(42): 23545: 23553) using reversible electrostatic interactions between acidic PAA and basic PBI (polybenzimidazole). PBI is an aromatic macromolecule with high mechanical strength, wherein imino groups can provide hydrogen bonding sites and can form reversible electrostatic interaction with carboxyl groups in PAA. This electrostatic action can impart a crosslinked structure to the binder and also can provide self-healing properties to the crosslinks between the binders, and can cause fracture and repair in response to changes in the volume of the electrode. In patent CN106753044B, sodium alginate and a cross-linking agent are mixed and stirred, and gel is formed after cross-linking reaction, so that the lithium ion battery aqueous binder is obtained. The obtained lithium ion battery aqueous binder is a high-strength aqueous binder for lithium ion batteries, and the hardness of a binder film is improved by times. Patent CN109411757A develops a composite cross-linked binder by mixing a linear polymer, a conductive polymer and a self-healing polymer, and the composite binder combines the characteristics of adhesion, mechanical properties, conductivity and self-healing property, and can make silicon particles still maintain conductivity after multiple cycles and pulverization and cracks generated after cycles realize self-healing, and improve the conductivity and stability of the whole electrode structure.
Therefore, for a binder to be applicable in a silicon-based anode, the following properties should be possessed: the copper foil has polar functional groups, so that stronger binding force with a silicon negative electrode material and a copper foil current collector is ensured; the electrode structure has a cross-linked network structure, can effectively cover the surface of an active substance, limits the movement and separation of the active substance and a conductive agent in the electrode circulation process, and stabilizes the electrode structure.
Disclosure of Invention
The invention aims to provide a simple and effective method for constructing an in-situ crosslinking polymer binder for a lithium ion battery. It is another object of the present invention to provide an electrode for a lithium ion battery prepared using the in-situ cross-linked polymer binder.
In order to achieve the purpose, the invention adopts the following technical scheme:
the polymer binder has a three-dimensional network structure and is prepared by in-situ polymerization of at least one of cationic polyacrylamide and a polymer containing a carboxyl functional group or a carboxylate functional group. The polymer containing carboxyl functional groups or carboxylate functional groups accounts for 50-90 percent by mass percent, and the cationic polyacrylamide accounts for 10-50 percent by mass percent.
In the in-situ crosslinked polymer binder, the polymer containing carboxyl functional groups is one or more of carboxymethyl cellulose, alginic acid hydrogel and polyacrylic acid. The polymer containing the carboxylate functional group is one or more of carboxymethyl cellulose salt, alginate hydrogel and polyacrylate.
In the in situ cross-linked polymeric binders of the present invention, the cationic polyacrylamide provides a plurality of sites of positive charge, and the polymer containing carboxyl or carboxylate functional groups is capable of providing sites of negative charge. At normal temperature, the two can be crosslinked in aqueous solution through electrostatic interaction between positive and negative charges, so that the binder forms a three-dimensional network structure. The binder with the network structure can prevent the active substances with nanometer sizes from agglomerating again in the process of coating the active substances into the electrode, and is beneficial to the dispersion uniformity of the active substances in the electrode. Meanwhile, the formation of the cross-linked structure can improve the mechanical strength of the binder and effectively limit the movement and separation of the electrode material. In addition, the electrostatic interaction between the positive and negative charges is reversible, giving the crosslinked adhesive a self-healing property, and enabling the electrode to maintain a stable structure over a long period of cycles.
The invention provides a lithium ion battery electrode, and the binder used by the electrode is the in-situ crosslinked polymer binder for the lithium ion battery. The specific preparation method of the electrode comprises the following steps:
step 1, mixing an active substance and a conductive additive into a solution of a polymer binder containing a carboxyl functional group or a carboxylate functional group according to a certain proportion to prepare a slurry with uniform dispersion.
And 2, adding the aqueous solution of the cationic polyacrylamide into the slurry, and uniformly mixing.
And 3, adding a proper amount of solvent to adjust the solid content of the slurry, and uniformly dispersing the slurry, wherein the solid content of the slurry is controlled to be 5-60%.
And 4, coating the uniformly mixed slurry on a metal current collector, drying and rolling, and then carrying out heat treatment for 1-24 hours in vacuum or protective atmosphere.
The active substance in the electrode is inorganic nonmetal, metal, alloy and oxide materials with lithium intercalation/deintercalation activity, and the mass fraction of the active substance in the electrode is 10-95%.
The conductive additive is one or more of metal powder, metal fiber, conductive carbon black, graphite material and carbon nano wire/tube, and accounts for 5-90% of the electrode by mass
The in-situ crosslinked polymer binder in the electrode accounts for 1-40% by mass.
The heat treatment temperature of the counter electrode is 60-150 ℃.
The invention has the advantages that:
1. the present invention innovatively uses cationic polyacrylamide as part of the binder in the lithium ion battery electrode. The polymer has the advantages of low cost, easy water solubility, no toxicity, no harm, strong hydrogen bond association capacity and good bonding effect on electrode materials.
2. The polymer binder provided by the invention can form a three-dimensional network structure through in-situ crosslinking in the normal-temperature pulping process, can improve the stability of the slurry, particularly the nano slurry, has an effective limiting effect on the volume change of the electrode, and maintains the stability of the electrode structure.
3. The crosslinking type binder provided by the invention is crosslinked through the electrostatic action between positive and negative charges, the electrostatic action is reversible, and the crosslinking type binder can be fractured and repaired along with the change of the volume of an electrode, so that the crosslinking binder has a self-healing effect, and the cycling stability of the electrode with serious volume change is obviously improved.
4. The binder used in the invention has simple cross-linking method and obvious effect, does not need to change the existing preparation process of the lithium ion battery electrode, has simple operation and high feasibility, and is easy to carry out industrial application.
In the preparation process of the electrode, water is completely used as a solvent, and no toxic organic solvent is required to be introduced.
Drawings
FIG. 1 is a graph comparing the cycling performance of nano-silicon electrodes prepared using different polymer binders.
Detailed Description
For a better understanding of the present invention, the present invention is described in further detail below with reference to specific examples. These examples are intended to illustrate the invention, but not to limit the scope of application of the invention. The numbering of the method steps serves to identify the method steps and does not limit the ordering of the method steps and the scope of the practice of the invention.
Example 1
Preparing an electrode: sodium carboxymethylcellulose (CMC) and Cationic Polyacrylamide (CPAM) were prepared as 2% aqueous solutions, respectively. 0.45g of spherical nano silicon particles with the particle size distribution of 50-150nm and 0.15g of conductive carbon black (super-P) are added into 3.75g of sodium carboxymethylcellulose aqueous solution and are fully and uniformly mixed, and then 3.75g of cationic polyacrylamide aqueous solution is added and is uniformly mixed with the slurry. Uniformly coating the prepared slurry on a copper foil current collector, and controlling the loading of active substance nano-silicon to be 1mg/cm2Left and right; air-drying the obtained pole piece at room temperature, cutting the pole piece into round pieces with the diameter of 14mm, compacting the round pieces by using a roller press, and controlling the compaction density to be 0.8g/cm3. The active material, conductive agent and binder in the obtained electrode were 60:20: 20.
The electrode prepared above was vacuum dried at 100 ℃ for 12 hours to remove moisture from the electrode.
And (3) performance testing: the electrode prepared in the above way is used as a working electrode, a metal lithium sheet is used as a counter electrode, a polypropylene microporous membrane (Celgard2300) is used as a diaphragm, and a conventional electrolyte 1M LiPF is injected6DEC EMC (1:1:1 vol%), assembled into button cells in a glove box under argon atmosphere. The assembled button cells were tested for constant current charge and discharge on a blue test system CT 2001A. The voltage range tested was 0.005-2V and the current density used was 300 mA/g. The results of the test are shown in table 1.
Example 2
Preparing an electrode: sodium alginate (Alg) and Cationic Polyacrylamide (CPAM) were prepared as 2% aqueous solutions, respectively. 0.45g of lamellar nano-silicon particles with the diameter of 100-150nm and the thickness of 30nm and 0.15g of conductive carbon black (super-P) are added into 5g of sodium alginate aqueous solution and are fully and uniformly mixed, and then 2.5g of cationic polyacrylamide aqueous solution is added and is uniformly mixed with the slurry. Uniformly coating the prepared slurry on a copper foil current collector, and controlling the loading of active substance nano-silicon to be 1mg/cm2Left and right; air-drying the obtained pole piece at room temperature, cutting the pole piece into round pieces with the diameter of 14mm, compacting the round pieces by using a roller press, and controlling the compaction density to be 0.8g/cm3. The active material, conductive agent and binder in the obtained electrode were 60:20: 20.
The electrode prepared above was vacuum dried at 100 ℃ for 12 hours to remove moisture from the electrode.
Electrochemical performance tests were performed on the above-described electrodes according to the "performance test" procedure in example 1, and the results are shown in table 1.
Example 3
Preparing an electrode: lithium Polyacrylate (PAALi) and Cationic Polyacrylamide (CPAM) were prepared as 2% aqueous solutions, respectively. 0.45g of silicon nanowire with the length of 1-2 mu m and the diameter of 60-150nm and 0.15g of conductive carbon black (super-P) are added into 4.5g of aqueous solution of lithium polyacrylate and are fully and uniformly mixed, and then 3g of cationic polyacrylamide aqueous solution is added and is uniformly mixed with the slurry. Uniformly coating the prepared slurry on a copper foil current collector, and controlling the loading of active substance nano-silicon to be 1mg/cm2Left and right; air-drying the obtained pole piece at room temperature, cutting the pole piece into round pieces with the diameter of 14mm, compacting the round pieces by using a roller press, and controlling the compaction density to be 0.8g/cm3. The active material, conductive agent and binder in the obtained electrode were 60:20: 20.
The electrode prepared above was vacuum dried at 100 ℃ for 12 hours to remove moisture from the electrode.
Electrochemical performance tests were performed on the above-described electrodes according to the "performance test" procedure in example 1, and the results are shown in table 1.
Example 4
Preparing an electrode: sodium carboxymethylcellulose (CMC), polyacrylic acid (PAA) and Cationic Polyacrylamide (CPAM) were prepared as 2% aqueous solutions, respectively. 0.45g of spherical nano silicon particles with the particle size distribution of 50-150nm, 0.12g of conductive carbon black (super-P) and 0.03g of carbon fibers (VGCF) are added into 3.5g of sodium carboxymethylcellulose aqueous solution and are fully and uniformly mixed, and then 1g of polyacrylic acid solution and 3g of cationic polyacrylamide aqueous solution are added and are uniformly mixed with the slurry. Uniformly coating the prepared slurry on a copper foil current collector, and controlling the loading of active substance nano-silicon to be 1mg/cm2Left and right; air-drying the obtained pole piece at room temperature, cutting the pole piece into round pieces with the diameter of 14mm, compacting the round pieces by using a roller press, and controlling the compaction density to be 0.8g/cm3. The active material, conductive agent and binder in the obtained electrode were 60:20: 20.
The electrode prepared above was vacuum dried at 100 ℃ for 12 hours to remove moisture from the electrode.
Electrochemical performance tests were performed on the above-described electrodes according to the "performance test" procedure in example 1, and the results are shown in table 1.
Example 5
Preparing an electrode: sodium alginate (Alg), polyacrylic acid (PAA) and Cationic Polyacrylamide (CPAM) were prepared as 2% aqueous solutions. 0.45g of spherical nano silicon particles with the particle size distribution of 50-150nm, 0.12g of conductive carbon black (super-P) and 0.03g of Carbon Nanotubes (CNTs) are added into a 3.5g of sodium alginate aqueous solution and are fully and uniformly mixed, and then 1g of polyacrylic acid solution and 3g of cationic polyacrylamide aqueous solution are added and are uniformly mixed with the slurry. Uniformly coating the prepared slurry on a copper foil current collector, and controlling the loading of active substance nano-silicon to be 1mg/cm2Left and right; air-drying the obtained pole piece at room temperature, cutting the pole piece into round pieces with the diameter of 14mm, compacting the round pieces by using a roller press, and controlling the compaction density to be 0.8g/cm3. The active material, conductive agent and binder in the obtained electrode were 60:20: 20.
The electrode prepared above was vacuum dried at 100 ℃ for 12 hours to remove moisture from the electrode.
Electrochemical performance tests were performed on the above-described electrodes according to the "performance test" procedure in example 1, and the results are shown in table 1.
Comparative example 1
Preparing sodium carboxymethylcellulose (CMC) into a 2% aqueous solution; 0.45g of spherical nano silicon particles with the particle size distribution of 50-150nm and 0.15g of conductive carbon black (super-P) are added into 7.5g of sodium carboxymethylcellulose (CMC) water solution and are fully and uniformly mixed, and no cationic polyacrylamide solution is added. Uniformly coating the prepared slurry on a copper foil current collector, and controlling the loading of active substance nano-silicon to be 1mg/cm2Left and right; air-drying the obtained pole piece at room temperature, cutting the pole piece into round pieces with the diameter of 14mm, compacting the round pieces by using a roller press, and controlling the compaction density to be 0.8g/cm3. The active material, conductive agent and binder in the obtained electrode were 60:20: 20.
The electrode prepared above was vacuum dried at 100 ℃ for 12 hours to remove moisture from the electrode.
Electrochemical performance tests were performed on the above-described electrodes according to the "performance test" procedure in example 1, and the results are shown in table 1.
Comparative example 2
Cationic Polyacrylamide (CPAM) was prepared as a 2% aqueous solution. 0.45g of spherical nano silicon particles with the particle size distribution of 50-150nm and 0.15g of conductive carbon black (super-P) are added into 7.5g of Cationic Polyacrylamide (CPAM) aqueous solution and are fully and uniformly mixed, and sodium carboxymethyl cellulose solution is not added. Uniformly coating the prepared slurry on a copper foil current collector, and controlling the loading of active substance nano-silicon to be 1mg/cm2Left and right; air-drying the obtained pole piece at room temperature, cutting the pole piece into round pieces with the diameter of 14mm, compacting the round pieces by using a roller press, and controlling the compaction density to be 0.8g/cm3. Active material in the obtained electrode: conductive agent: 60 parts of binder: 20: 20.
the electrode prepared above was vacuum dried at 100 ℃ for 12 hours to remove moisture from the electrode.
Electrochemical performance tests were performed on the above-described electrodes according to the "performance test" procedure in example 1, and the results are shown in table 1.
Table 1 electrochemical performance of nano-silicon electrodes prepared in examples 1-5 using different binders
As can be seen from examples 1 to 5 and comparative examples 1 to 2, the first cycle charge/discharge specific capacity, the first cycle library efficiency, and the capacity retention rate after 50 cycles of the nano silicon electrode obtained by using the polymer binder prepared by in-situ polymerization of at least one of the cationic polyacrylamide and the polymer containing the carboxyl functional group or the carboxylate functional group according to the present application are significantly higher than those of the binder prepared by using only the cationic polyacrylamide or only the polymer containing the carboxyl functional group or the carboxylate functional group.
Example 6
Sodium carboxymethylcellulose (CMC) and Cationic Polyacrylamide (CPAM) were prepared as 2% aqueous solutions. 1.6g of silicon oxide (SiO)x) The material, 0.2g of conductive carbon black (super-P) was added to 5g of sodium carboxymethylcellulose aqueous solution and mixed well, and then 5g of cationic polyacrylamide aqueous solution was added and mixed well with the above slurry. Uniformly coating the prepared slurry on a copper foil current collector, and controlling the loading of an active substance silicon oxide at 1.5mg/cm2Left and right; air-drying the obtained pole piece at room temperature, cutting the pole piece into round pieces with the diameter of 14mm, compacting the round pieces by using a roller press, and controlling the compaction density to be 1g/cm3. The active material, conductive agent and binder in the obtained electrode were 80:10: 10.
For comparison, electrodes were prepared using the same active material, conductive additive and electrode formulation, using sodium carboxymethylcellulose and cationic polyacrylamide alone as binders, respectively, with the same loading and compaction density, and were also air dried at room temperature.
The electrode prepared above was vacuum dried at 100 ℃ for 12 hours to remove moisture from the electrode.
The electrode prepared in the above way is used as a working electrode, a metal lithium sheet is used as a counter electrode, a polypropylene microporous membrane (Celgard2300) is used as a diaphragm, and a conventional electrolyte 1M LiPF is injected6DEC EMC (1:1:1 vol%), assembled into button cells in a glove box under argon atmosphere. The assembled button cells were tested for constant current charge and discharge on a blue test system CT 2001A. The voltage range tested was 0.005-2V and the current density used was 150 mA/g. The results of the test are shown in table 2.
Example 7
Lithium Polyacrylate (PAALi) and Cationic Polyacrylamide (CPAM) were prepared as 2% aqueous solutions. 1.6g of tin/carbon composite material and 0.2g of conductive carbon black (super-P) are added into 5g of sodium alginate aqueous solution and are fully and uniformly mixed, and then 5g of cationic polyacrylamide aqueous solution is added and is uniformly mixed with the slurry. Uniformly coating the prepared slurry on a copper foil current collector, and controlling the loading of an active substance silicon oxide at 1.5mg/cm2Left and right; air-drying the obtained pole piece at room temperature, cutting the pole piece into round pieces with the diameter of 14mm, compacting the round pieces by using a roller press, and controlling the compaction density to be 1g/cm3. The active material, conductive agent and binder in the obtained electrode were 80:10: 10.
For comparison, the same active material, conductive additive and electrode formulation were used, the lithium polyacrylate and cationic polyacrylamide were separately used as binders to prepare electrodes, the electrodes were controlled to have the same loading and compacted density, and the electrodes were also air-dried at room temperature.
The electrode prepared above was vacuum dried at 100 ℃ for 12 hours to remove moisture from the electrode.
The electrode prepared in the above way is used as a working electrode, a metal lithium sheet is used as a counter electrode, a polypropylene microporous membrane (Celgard2300) is used as a diaphragm, and a conventional electrolyte 1M LiPF is injected6DEC EMC (1:1:1 vol%) in an argon atmosphereAnd assembling a button cell in the glove box. The assembled button cells were tested for constant current charge and discharge on a blue test system CT 2001A. The voltage range tested was 0.005-2V and the current density used was 50 mA/g. The results of the test are shown in table 2.
Example 8
Sodium alginate (Alg) and Cationic Polyacrylamide (CPAM) were prepared as 2% aqueous solutions. 1.6g of lithium-rich solid solution material and 0.2g of conductive carbon black (super-P) are added into 5g of sodium alginate aqueous solution and are fully and uniformly mixed, and then 5g of cationic polyacrylamide aqueous solution is added and is uniformly mixed with the slurry. Uniformly coating the prepared slurry on a copper foil current collector, and controlling the loading of an active substance lithium-rich solid solution at 5mg/cm2Left and right; air-drying the obtained pole piece at room temperature, cutting the pole piece into round pieces with the diameter of 14mm, compacting the round pieces by using a roller press, and controlling the compaction density to be 1g/cm3. The active material, conductive agent and binder in the obtained electrode were 80:10: 10.
For comparison, the same active material, conductive additive and electrode proportion are used, sodium alginate and cationic polyacrylamide are respectively used as the binding agents to prepare the electrode, the electrode is controlled to have the same loading capacity and compaction density, and the electrode is also air-dried at room temperature.
The electrode prepared above was vacuum dried at 100 ℃ for 12 hours to remove moisture from the electrode.
The electrode prepared in the above way is used as a working electrode, a metal lithium sheet is used as a counter electrode, a polypropylene microporous membrane (Celgard2300) is used as a diaphragm, and a conventional electrolyte 1M LiPF is injected6DEC EMC (1:1:1 vol%), assembled into button cells in a glove box under argon atmosphere. The assembled button cells were tested for constant current charge and discharge on a blue test system CT 2001A. The voltage range tested was 2-4.8V and the current density used was 20 mA/g. The results of the test are shown in table 2.
Example 9
Sodium carboxymethylcellulose (CMC), polyacrylic acid (PAA) and Cationic Polyacrylamide (CPAM) were prepared as 2% waterAnd (3) solution. 3.6g of graphite-supported nano-silicon composite material, 0.16g of conductive carbon black (super-P) and 0.04g of Carbon Nanotubes (CNTs) are added into 5g of sodium carboxymethylcellulose aqueous solution and are fully and uniformly mixed, 1g of polyacrylic acid solution and 4g of cationic polyacrylamide aqueous solution are added and are uniformly mixed with the slurry, and a certain amount of water is added to adjust the solid content. Uniformly coating the prepared slurry on a copper foil current collector, and controlling the loading of an active substance silicon oxide at 4mg/cm2Left and right; air-drying the obtained pole piece at room temperature, cutting the pole piece into round pieces with the diameter of 14mm, compacting the round pieces by using a roller press, and controlling the compaction density to be 1.3g/cm3. The ratio of the active material, the conductive agent and the binder in the obtained electrode was 90:5: 5.
For comparison, electrodes were prepared using the same active material, conductive additive and electrode formulation, using sodium carboxymethylcellulose and cationic polyacrylamide alone as binders, respectively, with the same loading and compaction density, and were also air dried at room temperature.
The electrode prepared above was vacuum dried at 100 ℃ for 12 hours to remove moisture from the electrode.
The electrode prepared in the above way is used as a working electrode, a metal lithium sheet is used as a counter electrode, a polypropylene microporous membrane (Celgard2300) is used as a diaphragm, and a conventional electrolyte 1M LiPF is injected6DEC EMC (1:1:1 vol%), assembled into button cells in a glove box under argon atmosphere. The assembled button cells were tested for constant current charge and discharge on a blue test system CT 2001A. The voltage range tested was 0.005-2V and the current density used was 100 mA/g. The results of the test are shown in table 2.
Example 10
Sodium alginate (Alg), polyacrylic acid (PAA) and Cationic Polyacrylamide (CPAM) were prepared as 2% aqueous solutions. Adding 3.8g of amorphous carbon coated nano-silicon composite material, 0.08g of conductive carbon black (super-P) and 0.04g of carbon fiber (VGCF) into 3g of sodium carboxymethylcellulose aqueous solution, fully mixing uniformly, adding 1g of polyacrylic acid solution and 2g of cationic polyacrylamide aqueous solution, mixing uniformly with the slurry,a certain amount of water is added to adjust the solid content. Uniformly coating the prepared slurry on a copper foil current collector, and controlling the loading of the active substance carbon-coated nano silicon composite material to be 4mg/cm2Left and right; air-drying the obtained pole piece at room temperature, cutting the pole piece into round pieces with the diameter of 14mm, compacting the round pieces by using a roller press, and controlling the compaction density to be 1.3g/cm3. The active material, conductive agent and binder in the obtained electrode were 95:2: 3.
For comparison, the same active material, conductive additive and electrode proportion are used, sodium alginate and cationic polyacrylamide are respectively used as the binding agents to prepare the electrode, the electrode is controlled to have the same loading capacity and compaction density, and the electrode is also air-dried at room temperature.
The electrode prepared above was vacuum dried at 100 ℃ for 12 hours to remove moisture from the electrode.
The electrode prepared in the above way is used as a working electrode, a metal lithium sheet is used as a counter electrode, a polypropylene microporous membrane (Celgard2300) is used as a diaphragm, and a conventional electrolyte 1M LiPF is injected6DEC EMC (1:1:1 vol%), assembled into button cells in a glove box under argon atmosphere. The assembled button cells were tested for constant current charge and discharge on a blue test system CT 2001A. The voltage range tested was 0.005-2V and the current density used was 100 mA/g. The results of the test are shown in table 2.
Table 2 electrochemical performance of electrodes using different active materials in examples 6-10
As can be seen from examples 6 to 10 and comparative examples thereof, the first cycle charge/discharge specific capacity, the first cycle library efficiency, and the capacity retention rate after 50 cycles of the electrode obtained using the polymer binder of the present application, which is obtained by in situ polymerization of at least one of a cationic polyacrylamide and a polymer containing a carboxyl functional group or a carboxylate functional group, are significantly higher than those of binders using only a cationic polyacrylamide or only a polymer containing a carboxyl functional group or a carboxylate functional group.
It is to be understood that the invention is not limited in its application to the details of the foregoing description, and that modifications and variations may be effected by those skilled in the art in light of the above teachings, all within the scope and range of equivalents of the appended claims.
Claims (10)
1. The in-situ crosslinked polymer binder for the lithium ion battery is characterized by having a three-dimensional network structure and being prepared by in-situ polymerization of at least one of cationic polyacrylamide and a polymer containing a carboxyl functional group or a carboxylate functional group.
2. The in-situ crosslinked polymer binder for lithium ion batteries according to claim 1, wherein the polymer containing carboxyl functional groups or carboxylate functional groups accounts for 50% -90% and the cationic polyacrylamide accounts for 10% -50% by mass.
3. The in-situ crosslinked polymer binder for lithium ion batteries according to claim 1, wherein the polymer containing carboxyl functional groups is one or more of carboxymethyl cellulose, alginic acid hydrogel, and polyacrylic acid.
4. The in-situ crosslinked polymer binder for lithium ion batteries according to claim 1, wherein the polymer containing carboxylate functional groups is one or more of carboxymethyl cellulose salt, alginate hydrogel and polyacrylate.
5. An electrode for a lithium ion battery, wherein a binder used for the electrode is the in-situ crosslinked polymer binder for the lithium ion battery according to any one of claims 1 to 4.
6. A method for preparing an electrode according to claim 5, comprising the steps of:
step 1, mixing an active substance and a conductive additive agent into a solution of a polymer binder containing a carboxyl functional group or a carboxylate functional group according to a certain proportion to prepare a slurry with uniform dispersion;
step 2, adding an aqueous solution of cationic polyacrylamide into the slurry, and uniformly mixing;
step 3, adding a proper amount of solvent to adjust the solid content of the slurry, and uniformly dispersing the solid content of the slurry, wherein the solid content of the slurry is controlled to be 5-60%;
and 4, coating the uniformly mixed slurry on a metal current collector, drying and rolling, and then carrying out heat treatment for 1-24 hours in vacuum or protective atmosphere.
7. The method for preparing an electrode according to claim 6, wherein the active material in the step 1 is an inorganic nonmetal, metal, alloy, or oxide material having lithium intercalation/deintercalation activity, and the mass fraction of the active material in the electrode is 10-95%.
8. The method for preparing the electrode according to claim 6, wherein the conductive additive in the step 1 is one or more of metal powder, metal fiber, conductive carbon black, graphite material and carbon nano wire/tube, and the mass fraction of the conductive additive in the electrode is 5-90%.
9. The method for preparing the electrode according to claim 6, wherein the in-situ crosslinked polymer binder in the electrode in the step 1 accounts for 1-40% by mass.
10. The method for preparing an electrode according to claim 6, wherein the heat treatment temperature of the counter electrode in the step 4 is 60 ℃ to 150 ℃.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112133916A (en) * | 2020-08-17 | 2020-12-25 | 浙江大学 | Silicon-based negative electrode material binder of lithium ion battery and preparation method and application thereof |
| CN112279981A (en) * | 2020-10-20 | 2021-01-29 | 珠海冠宇电池股份有限公司 | Polymer binder containing soft phase region and hard phase region and preparation method and application thereof |
| CN113937290A (en) * | 2021-08-30 | 2022-01-14 | 济宁市海富电子科技有限公司 | Coating for lithium battery cathode and preparation method thereof |
| CN114805823A (en) * | 2022-04-25 | 2022-07-29 | 惠州锂威新能源科技有限公司 | Crosslinked composite binder, preparation method thereof, pole piece and secondary battery |
| CN116825968A (en) * | 2023-07-21 | 2023-09-29 | 三峡大学 | Preparation method of black phosphorus composite negative plate with three-dimensional electron/ion mass transfer channel |
| WO2023184208A1 (en) * | 2022-03-30 | 2023-10-05 | 宁德新能源科技有限公司 | Binder, electrochemical device and electronic device |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011084326A2 (en) * | 2009-12-21 | 2011-07-14 | Resodyn Corporation | Hemostatic agents and wound dressings |
| CN102473898A (en) * | 2009-07-01 | 2012-05-23 | 日本瑞翁株式会社 | Electrode for secondary battery, slurry for secondary battery electrode, and secondary battery |
| EP2797146A1 (en) * | 2012-02-16 | 2014-10-29 | LG Chem, Ltd. | Lithium secondary battery having anode containing aqueous binder |
| CN105051289A (en) * | 2013-03-26 | 2015-11-11 | 凯米罗总公司 | Process for production of paper or board |
| CN106159271A (en) * | 2015-04-22 | 2016-11-23 | 北京有色金属研究总院 | A kind of lithium ion battery in-situ cross-linked polymeric binder and the electrode of preparation thereof |
| CN107359351A (en) * | 2017-06-29 | 2017-11-17 | 郑州大学 | A kind of method that lithium ion battery prepares electrode slice with humic acid base water-based binder and using the binding agent |
| CN109390570A (en) * | 2018-09-28 | 2019-02-26 | 深圳市八六三新材料技术有限责任公司 | A kind of graphene coated silicon and preparation method thereof, application |
| CN109518521A (en) * | 2018-12-25 | 2019-03-26 | 昆山裕锦环保包装有限公司 | It is a kind of for packaging products of paper mould scrap-falling-proof processing slurry in auxiliary agent |
-
2019
- 2019-12-30 CN CN201911401163.XA patent/CN111106352A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102473898A (en) * | 2009-07-01 | 2012-05-23 | 日本瑞翁株式会社 | Electrode for secondary battery, slurry for secondary battery electrode, and secondary battery |
| WO2011084326A2 (en) * | 2009-12-21 | 2011-07-14 | Resodyn Corporation | Hemostatic agents and wound dressings |
| EP2797146A1 (en) * | 2012-02-16 | 2014-10-29 | LG Chem, Ltd. | Lithium secondary battery having anode containing aqueous binder |
| CN105051289A (en) * | 2013-03-26 | 2015-11-11 | 凯米罗总公司 | Process for production of paper or board |
| CN106159271A (en) * | 2015-04-22 | 2016-11-23 | 北京有色金属研究总院 | A kind of lithium ion battery in-situ cross-linked polymeric binder and the electrode of preparation thereof |
| CN107359351A (en) * | 2017-06-29 | 2017-11-17 | 郑州大学 | A kind of method that lithium ion battery prepares electrode slice with humic acid base water-based binder and using the binding agent |
| CN109390570A (en) * | 2018-09-28 | 2019-02-26 | 深圳市八六三新材料技术有限责任公司 | A kind of graphene coated silicon and preparation method thereof, application |
| CN109518521A (en) * | 2018-12-25 | 2019-03-26 | 昆山裕锦环保包装有限公司 | It is a kind of for packaging products of paper mould scrap-falling-proof processing slurry in auxiliary agent |
Non-Patent Citations (2)
| Title |
|---|
| 何静 等: "CPAM的合成及CPAMCMC二元纸张增强体系的初步研究", 《北京林业大学学报》 * |
| 巩筱等: "TOCNs、聚丙烯酰胺对羧甲基纤维素钠膜性能的影响", 《食品科学》 * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112133916A (en) * | 2020-08-17 | 2020-12-25 | 浙江大学 | Silicon-based negative electrode material binder of lithium ion battery and preparation method and application thereof |
| CN112279981A (en) * | 2020-10-20 | 2021-01-29 | 珠海冠宇电池股份有限公司 | Polymer binder containing soft phase region and hard phase region and preparation method and application thereof |
| CN112279981B (en) * | 2020-10-20 | 2023-02-03 | 珠海冠宇电池股份有限公司 | Polymer binder containing soft phase region and hard phase region and preparation method and application thereof |
| CN113937290A (en) * | 2021-08-30 | 2022-01-14 | 济宁市海富电子科技有限公司 | Coating for lithium battery cathode and preparation method thereof |
| WO2023184208A1 (en) * | 2022-03-30 | 2023-10-05 | 宁德新能源科技有限公司 | Binder, electrochemical device and electronic device |
| CN114805823A (en) * | 2022-04-25 | 2022-07-29 | 惠州锂威新能源科技有限公司 | Crosslinked composite binder, preparation method thereof, pole piece and secondary battery |
| CN116825968A (en) * | 2023-07-21 | 2023-09-29 | 三峡大学 | Preparation method of black phosphorus composite negative plate with three-dimensional electron/ion mass transfer channel |
| CN116825968B (en) * | 2023-07-21 | 2024-03-19 | 三峡大学 | Preparation method of black phosphorus composite negative plate with three-dimensional electron/ion mass transfer channel |
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