CN115986054A - Silicon-based electrode and preparation method and application thereof - Google Patents
Silicon-based electrode and preparation method and application thereof Download PDFInfo
- Publication number
- CN115986054A CN115986054A CN202310013800.6A CN202310013800A CN115986054A CN 115986054 A CN115986054 A CN 115986054A CN 202310013800 A CN202310013800 A CN 202310013800A CN 115986054 A CN115986054 A CN 115986054A
- Authority
- CN
- China
- Prior art keywords
- silicon
- active layer
- groove
- based active
- pole piece
- 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
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
The invention discloses a silicon-based electrode and a preparation method and application thereof. The silicon-based electrode comprises a current collector and a silicon-based active layer arranged on the surface of the current collector, wherein a groove which does not penetrate through the silicon-based active layer is formed in the silicon-based active layer, and the silicon-based active layer has a porous structure. According to the invention, the pore-forming agent is coated after the grooves are formed on the surface of the pole piece, and the coating and drying are controlled, so that more gaps can be formed on the surface of the pole piece, especially on the grooves.
Description
Technical Field
The invention belongs to the field of lithium ion batteries, and particularly relates to a silicon-based electrode and a preparation method and application thereof.
Background
The lithium ion battery has the characteristics of high voltage, long cycle life, environmental friendliness and the like, and the requirements of people on the energy density of the lithium ion battery are higher and higher along with the rapid development of new energy industries in recent years. There are two methods for increasing the energy density of lithium ion batteries: novel and high-capacity anode and cathode materials are used, and the surface density of the conventional anode and cathode is improved. In the aspect of materials, a ternary positive electrode material with high nickel content and a silicon-based negative electrode material with high theoretical specific capacity are developed and used; on the aspect of the electrode, the content of active substances in a unit area is increased, namely, a high-load electrode is prepared.
Although both methods can increase the energy density of the battery, both methods have their own problems. In the aspect of the positive electrode material, the thermal stability and the safety stability of the material are gradually reduced along with the increase of the content of nickel, and the degradation speed of the material is accelerated. In the aspect of the negative electrode material, although the silicon-based negative electrode material has higher specific capacity, the material can generate very large volume change in the charging and discharging process, so that an SEI film is cracked and regenerated, and particle crushing and conductive network collapse can occur after multiple cycles. Although a novel material is not selected for the high-load electrode, the increase of the area density causes difficulty in wetting the electrolyte and a longer diffusion path of lithium ions, thereby affecting the performance of the battery. In addition, in order to raise the energy density of the battery as high as possible, both methods are often used simultaneously.
Therefore, the current negative pole piece of the high specific energy battery simultaneously faces the problems of large thickness, difficult lithium ion diffusion, poor electrolyte infiltration, large pole piece expansion and the like.
Disclosure of Invention
The invention aims to provide a silicon-based electrode and a preparation method and application thereof.
In order to achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, the invention provides a silicon-based electrode, which comprises a current collector and a silicon-based active layer arranged on the surface of the current collector, wherein a groove which does not penetrate through the silicon-based active layer is arranged on the silicon-based active layer, and the silicon-based active layer has a porous structure.
Preferably, the cross-sectional shape of the groove is any one of a grid, a cross, a ring, a diamond, or a zigzag.
Preferably, the depth of the groove is 5-50% of the thickness of the silicon-based active layer.
Preferably, the line width of the groove is 1 to 200 μm.
Preferably, the silicon-based active layer includes an active material, a binder, and a conductive agent.
Preferably, the active substance comprises a silicon-based material and a carbon material, and the mass ratio of the silicon-based material to the carbon material is 1.
Preferably, the carbon material includes at least one of graphite, hard carbon, and soft carbon.
Preferably, the mass ratio of the active material to the conductive agent is from 99 to 80.
Preferably, the silicon-based active layer has an areal density of 10 to 30mg/cm 2 Preferably 18 to 28mg/cm 2 。
Preferably, the number of the silicon-based active layers is a single layer,
or the number of the silicon-based active layers is at least two, and the at least two silicon-based active layers are sequentially stacked to form the composite active layer.
Preferably, the areal density of the silicon-based active layer decreases in a direction away from the current collector.
In a second aspect, the present invention provides a method for preparing a silicon-based electrode as defined in the first aspect, said method comprising the steps of:
(1) Preparing silicon-based slurry;
(2) Coating the silicon-based slurry on a current collector, drying and then rolling to obtain a pole piece;
(3) Forming a groove on the surface of the pole piece to obtain the pole piece with the groove;
(4) Coating a pore-forming agent on one side of the groove of the pole piece with the groove, and drying while coating to obtain the silicon-based electrode;
wherein the drying temperature is higher than the decomposition temperature of the pore-forming agent.
Preferably, the number of the coating in the step (2) is at least 1, and the drying step is performed after each coating.
Preferably, the step (3) of forming the groove on the surface of the pole piece comprises at least one of cutting, laser etching or gravure pressing.
Preferably, the pore-forming agent in the step (4) is at least one of N-methyl pyrrolidone, acetone, alcohol, oxalic acid solution, ammonium carbonate solution, ammonium bicarbonate solution or azodicarbonamide solution.
Preferably, the concentration of the oxalic acid solution, ammonium carbonate solution, ammonium bicarbonate solution or azodicarbonamide solution is independently 0.2 to 12mol/L.
In a third aspect, the present invention provides a lithium ion battery, which includes the silicon-based electrode of the first aspect.
Compared with the prior art, the invention has the following beneficial effects:
according to the invention, the pore-forming agent is coated after the grooves are formed on the surface of the pole piece, and the coating and drying are controlled, so that more gaps can be formed on the surface of the pole piece, especially on the grooves.
Drawings
FIG. 1 is a drawing of a pattern on a pole piece surface after laser etching in one embodiment of the invention;
FIG. 2 is a drawing of a pattern on the surface of a pole piece after laser etching in one embodiment of the invention;
FIG. 3 is a drawing of a pattern on the surface of a pole piece after laser etching in one embodiment of the present invention;
FIG. 4 is a drawing of the pattern on the surface of the pole piece after laser etching in one embodiment of the present invention.
Detailed Description
The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.
The technical solution of the present invention is further described below by way of specific embodiments.
The invention provides a silicon-based electrode in one embodiment, which comprises a current collector and a silicon-based active layer arranged on the surface of the current collector, wherein a groove which does not penetrate through the silicon-based active layer is arranged on the silicon-based active layer, and the silicon-based active layer has a porous structure.
In the silicon-based electrode provided by one embodiment of the invention, the silicon-based active layer has a porous structure and is provided with the groove, so that the wettability of the silicon-based electrode can be improved, the resistance can be reduced, the expansion inhibiting effect can be good, and the feasibility for further application of preparing a high-load and high-specific-energy battery is provided.
In one embodiment, the current collector may be selected from commercially available negative current collectors including, but not limited to, any one of copper foil, aluminum foil, nickel foil, and titanium foil.
In one embodiment, the cross-sectional shape of the groove is any one of a grid, a cross, a ring, a diamond, or a zigzag.
In one embodiment, the depth of the recess is 5-50% of the thickness of the silicon-based active layer, such as 5%, 8%, 10%, 12.5%, 15%, 18%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or the like.
In one embodiment, the line width of the recess is 1-200 μm, such as 1 μm, 3 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, or 200 μm, etc.
In one embodiment, the silicon-based active layer includes an active material, a binder, and a conductive agent.
In one embodiment, the active material comprises a silicon-based material and a carbon material, wherein the mass ratio of the silicon-based material to the carbon material is 1.
In one embodiment, the silicon-based material includes, but is not limited to, at least one of silicon oxygen, silicon carbon, pure silicon, or a silicon alloy.
In one embodiment, the carbon material comprises at least one of graphite, hard carbon, and soft carbon.
In one embodiment, the conductive agent may be a commercially available conductive agent including, but not limited to, at least one of carbon black, SP, single-walled carbon tubes, multi-walled carbon tubes, carbon fibers, and graphene.
In one embodiment, the mass ratio of the active material to the conductive agent is from 99.
In one embodiment, the silicon-based active layer has an areal density of 10 to 30mg/cm 2 E.g. 10mg/cm 2 、12mg/cm 2 、15mg/cm 2 、17mg/cm 2 、20mg/cm 2 、23mg/cm 2 、26mg/cm 2 Or 30mg/cm 2 Etc., preferably 18 to 28mg/cm 2 . The areal density referred to herein refers to the total areal density of a single layer or multiple layers.
In one embodiment, the number of layers of the silicon-based active layer is a single layer.
In one embodiment, the number of the silicon-based active layers is at least two, and the at least two silicon-based active layers are sequentially stacked to form the composite active layer. The composite active layer is obtained in a multi-layer mode, so that a high-load silicon-based thick electrode can be obtained, and higher energy density is facilitated to be obtained.
Because the silicon-based electrode provided by the embodiment of the invention has the porous structure and the groove, the problems of poor wettability, increased internal resistance and increased expansion of the silicon-based thick electrode can be solved.
In one embodiment, the areal density of the silicon-based active layer decreases in a direction away from the current collector.
In another embodiment, the present invention provides a method for preparing the silicon-based electrode, which comprises the following steps:
(1) Preparing silicon-based slurry;
(2) Coating the silicon-based slurry on a current collector, drying and then rolling to obtain a pole piece;
(3) Forming a groove on the surface of the pole piece to obtain the pole piece with the groove;
(4) Coating a pore-forming agent on one side of the groove of the pole piece with the groove, and drying while coating to obtain the silicon-based electrode;
wherein the drying temperature is higher than the decomposition temperature of the pore-forming agent.
According to the method provided by one embodiment of the invention, the pore-forming agent is coated after the grooves are formed on the surface of the pole piece, and the coating and the drying are controlled, so that more gaps can be formed on the surface of the pole piece, particularly on the grooves.
In one embodiment, in step (2), the silicon-based slurry is coated on both side surfaces of the current collector.
In one embodiment, the number of coating times in step (2) is at least 1, and the step of drying is performed after each coating. The porosity of the pole piece can be controlled through layered coating, the wettability of the silicon-based electrode is improved, and the expansion effect of the silicon-based material is inhibited.
In one embodiment, the step (3) of forming the groove on the surface of the pole piece comprises at least one of cutting, laser etching or gravure pressing.
In one embodiment, the pore forming agent in step (4) is at least one of N-methyl pyrrolidone, alcohol, oxalic acid solution, ammonium carbonate solution, ammonium bicarbonate solution or azodicarbonamide solution.
In one embodiment, the solvent of the azodicarbonamide solution is at least one of dimethyl sulfoxide, dimethylformamide or hot ethylene glycol.
In one embodiment, the alcohol is industrial ethanol.
In one embodiment, the concentration of the oxalic acid solution, ammonium carbonate solution, ammonium bicarbonate solution, or azodicarbonamide solution is independently 0.2 to 12mol/L, such as 0.2mol/L, 0.5mol/L, 1mol/L, 2mol/L, 3mol/L, 4mol/L, 5mol/L, 6mol/L, 7mol/L, 8mol/L, 9mol/L, 10mol/L, 11mol/L, or 12mol/L, and the like. Wherein, the term "independently" means that the concentrations of various solutions are selected within the range, the concentrations of different solutions are independent and not influenced, and the concentrations of different solutions can be the same or different.
In one embodiment, the preparation method of the silicon-based electrode comprises the following steps:
s1, preparing a silicon-based slurry from a silicon-based material, a carbon material, a conductive agent and a binder in a homogenization tank according to a certain proportion and sequence;
s2, coating the surface of two sides of a negative current collector according to a certain surface density, continuously coating the front and back surfaces according to a certain surface density after drying the front and back surfaces for the first time, and rolling the front and back surfaces to a preset thickness according to a certain compaction density after drying the front and back surfaces for the second time;
s3, cutting, laser etching or gravure pressing the rolled electrode plate according to a required shape to form a groove with a certain cross-sectional shape on the surface of the electrode plate;
and S4, coating the processed electrode plate with a pore-forming agent, wherein the coating mode is completed by a coating machine, the coating of the pore-forming agent is performed while the drying is performed, the drying temperature is higher than the decomposition temperature of the pore-forming agent, and the silicon-based electrode is obtained after the drying.
The invention provides in yet another embodiment a lithium ion battery comprising a silicon-based electrode as described above.
The following are typical but non-limiting examples:
example 1
The embodiment provides a silicon-based electrode, which includes a current collector and a silicon-based active layer disposed on the surface of the current collector, wherein a groove that does not penetrate through the silicon-based active layer is disposed on the silicon-based active layer, and the silicon-based active layer has a porous structure;
the current collector is a copper foil;
the cross section of the groove is in a grid shape;
the depth of the groove is 10% of the thickness of the silicon-based active layer;
the line width of the groove is 1 mu m;
the silicon-based active layer comprises silica, a carbon material, a conductive agent and SBR, wherein the carbon material is graphite, the conductive agent is SP and a single-walled carbon tube, and the mass ratio of the silica to the graphite to the SP to the single-walled carbon tube to the SBR is 18.7;
the number of layers of the silicon-based active layer is two, the two silicon-based active layers are sequentially stacked to form a composite active layer, and the surface density of the silicon-based active layer is 10mg/cm in sequence along the direction away from the current collector 2 And 8mg/cm 2 。
The present embodiment further provides a method for manufacturing the silicon-based electrode, including the following steps:
firstly, silica, graphite, SP, a single-walled carbon tube and SBR with the mass ratio of 18.7 2 The surface density of the copper foil is coated on the copper foil in an extrusion coating mode, and the copper foil is dried and then coated according to the ratio of 8mg/cm 2 The surface density of the silicon substrate is coated on a prepared pole piece, the pole piece is rolled according to a certain compaction density after being dried, then the pole piece is processed by a laser etching method to be in a grid shape (see figure 1), wherein the line width of a groove refers to the width of a line forming the grid, then an acetone pore-forming agent is used for uniformly coating the rolled pole piece, and the silicon substrate high-load negative pole piece, namely a silicon substrate electrode, is obtained after coating and drying.
Example 2
The embodiment provides a silicon-based electrode, which comprises a current collector and a silicon-based active layer arranged on the surface of the current collector, wherein a groove which does not penetrate through the silicon-based active layer is arranged on the silicon-based active layer, and the silicon-based active layer has a porous structure;
the current collector is a copper foil;
the cross section of the groove is annular;
the depth of the groove is 30% of the thickness of the silicon-based active layer;
the line width of the groove is 10 mu m;
the silicon-based active layer comprises silicon carbon, a carbon material, a conductive agent and SBR, wherein the carbon material is graphite, the conductive agent is SP and a single-walled carbon tube, and the mass ratio of the silicon carbon to the graphite to the SP to the single-walled carbon tube to the SBR is (18.7);
the number of the silicon-based active layers is two, the two silicon-based active layers are sequentially stacked to form a composite active layer, and the surface density of the silicon-based active layers is 16mg/cm in sequence along the direction away from the current collector 2 And 12mg/cm 2 。
The present embodiment further provides a method for manufacturing the silicon-based electrode, including the following steps:
firstly, silicon carbon, graphite, SP, a single-walled carbon tube and SBR with the mass ratio of 18.7 2 The surface density of the copper foil is coated on the copper foil in a transfer coating mode, and the copper foil is dried and then coated according to the ratio of 12mg/cm 2 The surface density of the N-methyl pyrrolidone is coated on a prepared pole piece, the pole piece is rolled according to a certain compaction density after being dried, then the pole piece is processed by a laser etching method to be in a ring shape (see figure 2), wherein the line width of a groove refers to the width of a line of each circle forming the ring shape, then the N-methyl pyrrolidone is evenly coated on the rolled pole piece, and the silicon-based high-load negative pole piece, namely a silicon-based electrode, is obtained after coating and drying are carried out simultaneously.
Example 3
The embodiment provides a silicon-based electrode, which comprises a current collector and a silicon-based active layer arranged on the surface of the current collector, wherein a groove which does not penetrate through the silicon-based active layer is arranged on the silicon-based active layer, and the silicon-based active layer has a porous structure;
the current collector is a copper foil;
the cross section of the groove is in a grid shape;
the depth of the groove is 20% of the thickness of the silicon-based active layer;
the line width of the groove is 1 mu m;
the silicon-based active layer comprises pure silicon, a carbon material, a conductive agent and SBR, wherein the carbon material is graphite, the conductive agent is SP and a single-walled carbon tube, and the mass ratio of the pure silicon to the graphite to the SP to the single-walled carbon tube to the SBR is 46.5;
the number of the silicon-based active layers is one, and the surface density of the silicon-based active layers is 10mg/cm 2 。
The present embodiment further provides a method for manufacturing the silicon-based electrode, including the following steps:
firstly, pure silicon, graphite, SP, a single-walled carbon tube and SBR with the mass ratio of 46 2 The surface density of the electrode is coated on a copper foil in an extrusion coating mode, the electrode is rolled according to a certain compaction density after being dried, then the electrode is processed by a gravure pressing method, the electrode is processed into a ring shape, then ammonium bicarbonate solution with the concentration of 1.5mol/L is uniformly coated on the rolled electrode, and the silicon-based high-load negative electrode plate, namely a silicon-based electrode, is obtained while coating and drying.
Example 4
The embodiment provides a silicon-based electrode, which comprises a current collector and a silicon-based active layer arranged on the surface of the current collector, wherein a groove which does not penetrate through the silicon-based active layer is arranged on the silicon-based active layer, and the silicon-based active layer has a porous structure;
the current collector is nickel foil;
the cross section of the groove is in a cross shape;
the depth of the groove is 25% of the thickness of the silicon-based active layer;
the line width of the groove is 200 mu m;
the silicon-based active layer comprises silica, a carbon material, a conductive agent and SBR, wherein the carbon material is graphite, the conductive agent is SP and a multi-walled carbon tube, and the mass ratio of the silica to the graphite to the SP to the multi-walled carbon tube to the SBR is 30;
the number of the silicon-based active layers is two, the two silicon-based active layers are sequentially stacked to form a composite active layer, and the surface density of the silicon-based active layers is 18mg/cm in sequence along the direction away from the current collector 2 And 12mg/cm 2 。
The present embodiment further provides a method for manufacturing the silicon-based electrode, including the following steps:
firstly, silica, graphite, SP, a multi-walled carbon tube and SBR in a mass ratio of 30 2 The surface density of the copper foil is coated on the copper foil in a squeezing mode, and the copper foil is dried and then coated according to the ratio of 12mg/cm 2 Coating the prepared pole piece with the surface density, drying, rolling according to a certain compaction density, processing the pole piece by a laser etching method to form a cross (see figure 3), wherein the line width of the groove refers to the width of each cross, then uniformly coating the rolled pole piece with an oxalic acid solution pore-forming agent, the concentration of the oxalic acid solution is 5mol/L, and drying while coating to obtain the silicon-based high-load negative pole piece, namely the silicon-based electrode.
Example 5
The embodiment provides a silicon-based electrode, which comprises a current collector and a silicon-based active layer arranged on the surface of the current collector, wherein a groove which does not penetrate through the silicon-based active layer is arranged on the silicon-based active layer, and the silicon-based active layer has a porous structure;
the current collector is nickel foil;
the cross section of the groove is in a diamond shape;
the depth of the groove is 12% of the thickness of the silicon-based active layer;
the line width of the groove is 100 mu m;
the silicon-based active layer comprises silica, a carbon material, a conductive agent and SBR, wherein the carbon material is graphite, the conductive agent is SP and a multi-wall carbon tube, and the mass ratio of the silica to the graphite to the SP to the multi-wall carbon tube to the SBR is 45;
the number of layers of the silicon-based active layer is two, the two silicon-based active layers are sequentially stacked to form a composite active layer, and the surface density of the silicon-based active layer is 13mg/cm in sequence along the direction away from the current collector 2 And 10mg/cm 2 。
The present embodiment further provides a method for manufacturing the silicon-based electrode, including the following steps:
first, a mixture of silica, graphite, SP, multi-walled carbon tube, SBRAdding into a double-planet stirring tank in a certain order, mixing uniformly according to 13mg/cm 2 The surface density of the copper foil is coated on the copper foil in a squeezing mode, and the copper foil is dried and then coated according to the ratio of 10mg/cm 2 Coating the prepared pole piece with the surface density, drying, rolling according to a certain compaction density, processing the pole piece by a laser etching method to form rhombuses (see figure 4), wherein the line width of the groove refers to the width of each rhombus line, then uniformly coating a pore-forming agent of ammonium carbonate solution on the rolled pole piece, the concentration of the ammonium carbonate solution is 7mol/L, and drying while coating to obtain the silicon-based high-load negative pole piece, namely the silicon-based electrode.
Example 6
The difference from the embodiment 1 is that the depth of the groove is 60% of the thickness of the silicon-based active layer.
Example 7
The difference from example 1 is that the depth of the groove is 60% of the thickness of the silicon-based active layer, and the line width of the groove is 500 microns.
Comparative example 1
The difference from example 1 is that the preparation method is as follows:
firstly, silica, graphite, SP, a single-walled carbon tube and SBR materials with the mass ratio of 18.7 2 The surface density of the copper foil is coated on the copper foil in an extrusion coating mode, and the copper foil is dried and then coated according to the ratio of 8mg/cm 2 Coating the prepared electrode plate with the surface density, drying, rolling according to a certain compaction density, then uniformly coating an acetone pore-forming agent on the rolled electrode plate, and drying while coating to obtain the silicon-based electrode.
Comparative example 2
The difference from example 1 is that the preparation method is as follows:
firstly, silica, graphite, SP, a single-walled carbon tube and SBR materials with the mass ratio of 18.7 2 The surface density of the copper foil is coated on the copper foil in a squeezing modeCoating, drying, and coating at a ratio of 8mg/cm 2 Coating the prepared pole piece with the surface density, drying, rolling according to a certain compaction density, uniformly coating an acetone pore-forming agent on the rolled pole piece, drying while coating to obtain the silicon-based high-load negative pole piece, then processing the pole piece by a laser etching method, and processing the pole piece into a grid shape to obtain the silicon-based electrode.
And (3) testing:
and (3) testing the imbibition time: mu.L of PC solvent was taken out by a syringe, dropped on the pole piece, and the time when the PC solvent was completely absorbed was recorded.
And (3) electricity deduction test: the pole pieces of the above examples or comparative examples were wiped to obtain single-sided pole pieces, dried, and then assembled in the order of negative electrode case, lithium sheet, separator, electrolyte, negative electrode sheet, gasket, spring sheet, and positive electrode case to be buckled for testing, with cycle number of 50 cycles and charge-discharge rate of 0.5C/0.5C.
And (3) resistance testing: the resistance test was performed with a voltmeter.
TABLE 1
And (3) analysis:
the pole piece which is not subjected to laser etching in the comparative example 1 has poor wettability inside the pole piece, large internal resistance and low cycle retention rate.
Comparative example 2 etching was performed after the pore-forming agent was coated, but at this time, the surface wettability was enhanced, but the internal wettability was still affected, and the cycle retention rate was reduced.
Example 6 the depth of the groove is too large, which affects the conduction of electrons, resulting in an increase in internal resistance and a decrease in cycle retention.
Comparing example 1 with example 7, the larger the line width of the groove, the smaller the area density, the smaller the internal resistance of the pole piece, but when the line width is too large or the depth is too large, the conduction of electrons is affected, but the internal resistance is increased, and the cycle retention rate is reduced.
The applicant states that the present invention is illustrated in detail by the above examples, but the present invention is not limited to the above detailed methods, i.e. it is not meant that the present invention must rely on the above detailed methods for its implementation. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.
Claims (10)
1. The silicon-based electrode is characterized by comprising a current collector and a silicon-based active layer arranged on the surface of the current collector, wherein a groove which does not penetrate through the silicon-based active layer is formed in the silicon-based active layer, and the silicon-based active layer has a porous structure.
2. The silicon-based electrode according to claim 1, wherein the cross-sectional shape of the groove is any one of a grid, a cross, a ring, a diamond or a zigzag;
preferably, the depth of the groove is 5-50% of the thickness of the silicon-based active layer;
preferably, the line width of the groove is 1 to 200 μm.
3. Silicon-based electrode according to claim 1 or 2, characterized in that the silicon-based active layer comprises an active substance, a binder and a conductive agent;
preferably, the active substance comprises a silicon-based material and a carbon material, and the mass ratio of the silicon-based material to the carbon material is 1;
preferably, the carbon material includes at least one of graphite, hard carbon, and soft carbon;
preferably, the mass ratio of the active material to the conductive agent is from 99 to 80.
4. According to the claimsThe method according to any one of claims 1 to 3, wherein the silicon-based active layer has an areal density of 10 to 30mg/cm 2 Preferably 18 to 28mg/cm 2 。
5. The method according to any of claims 1 to 4, wherein the number of silicon-based active layers is a single layer,
or the number of the silicon-based active layers is at least two, and the at least two silicon-based active layers are sequentially stacked to form a composite active layer;
preferably, the areal density of the silicon-based active layer decreases in a direction away from the current collector.
6. A method for the preparation of a silicon-based electrode according to any one of claims 1 to 5, comprising the steps of:
(1) Preparing silicon-based slurry;
(2) Coating the silicon-based slurry on a current collector, drying and then rolling to obtain a pole piece;
(3) Forming a groove on the surface of the pole piece to obtain the pole piece with the groove;
(4) Coating a pore-forming agent on one side of the groove of the pole piece with the groove, and drying while coating to obtain the silicon-based electrode;
wherein the drying temperature is higher than the decomposition temperature of the pore-forming agent.
7. The method of claim 6, wherein the number of applications in step (2) is at least 1, and wherein the step of drying is performed after each application.
8. The method of claim 6 or 7, wherein the step (3) of forming the grooves on the surface of the pole piece comprises at least one of cutting, laser etching or gravure pressing.
9. The method according to any one of claims 6 to 8, wherein the pore-forming agent of step (4) is at least one of N-methylpyrrolidone, acetone, alcohol, oxalic acid solution, ammonium carbonate solution, ammonium bicarbonate solution, or azodicarbonamide solution;
preferably, the concentration of the oxalic acid solution, ammonium carbonate solution, ammonium bicarbonate solution or azodicarbonamide solution is independently 0.2 to 12mol/L.
10. A lithium ion battery comprising a silicon-based electrode according to any one of claims 1 to 5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310013800.6A CN115986054A (en) | 2023-01-05 | 2023-01-05 | Silicon-based electrode and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310013800.6A CN115986054A (en) | 2023-01-05 | 2023-01-05 | Silicon-based electrode and preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115986054A true CN115986054A (en) | 2023-04-18 |
Family
ID=85966552
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310013800.6A Pending CN115986054A (en) | 2023-01-05 | 2023-01-05 | Silicon-based electrode and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115986054A (en) |
-
2023
- 2023-01-05 CN CN202310013800.6A patent/CN115986054A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110581311B (en) | Composite solid electrolyte membrane, preparation method thereof and solid battery | |
| JP2022506297A (en) | Modified solid electrolyte membrane, its manufacturing method, and lithium battery | |
| CN110707287B (en) | Metal lithium negative electrode, preparation method thereof and lithium battery | |
| Zhang et al. | Super‐Assembled Hierarchical CoO Nanosheets‐Cu Foam Composites as Multi‐Level Hosts for High‐Performance Lithium Metal Anodes | |
| NL2007153C2 (en) | Electrode assembly for a lithium ion battery, process for the production of such electrode assembly, and lithium ion battery comprising such electrode assemblies. | |
| CN114927639B (en) | Negative electrode plate, preparation method thereof and secondary battery | |
| CN110752345A (en) | Pole piece, preparation method thereof and lithium ion battery | |
| CN112687865A (en) | Lithium ion battery cathode slurry, preparation method and application thereof | |
| CN112290098A (en) | Anti-flatulence polymer lithium ion battery and preparation method thereof | |
| CN117096273B (en) | Protective layer modified lithium metal composite negative electrode, preparation method thereof and battery | |
| CN113270691A (en) | Pole piece/diaphragm integrated lithium ion battery and preparation method thereof | |
| WO2018119956A1 (en) | Porous aluminum-foil anode and method for preparing same, and lithium secondary battery | |
| CN116014225A (en) | Sodium ion battery | |
| CN115986054A (en) | Silicon-based electrode and preparation method and application thereof | |
| CN116190668A (en) | Ultralight current collector and preparation method and application thereof | |
| CN114512633A (en) | Negative plate and battery comprising same | |
| CN114388726B (en) | High-magnification thick positive electrode and preparation method thereof | |
| CN114512670A (en) | Negative plate and battery comprising same | |
| CN116598617B (en) | Lithium metal composite negative electrode, preparation method thereof and battery | |
| CN115719795A (en) | Secondary battery | |
| CN115425175A (en) | Thick electrode and preparation method and application thereof | |
| CN115394952A (en) | Thick electrode and manufacturing method and application thereof | |
| CN116031371A (en) | Three-dimensional porous silicon-carbon composite lithium battery negative electrode, preparation method thereof and lithium secondary battery | |
| CN117253978A (en) | Negative electrode plate, preparation method thereof and lithium ion battery | |
| CN116014359A (en) | Lithium supplementing diaphragm and preparation method and application thereof |
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 |