CN115832202A - Negative pole piece, lithium ion battery and preparation method thereof - Google Patents
Negative pole piece, lithium ion battery and preparation method thereof Download PDFInfo
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Abstract
The invention belongs to the technical field of lithium ion batteries, and particularly relates to a negative electrode plate, a lithium ion battery and a preparation method thereof. The invention provides a negative pole piece, which comprises a current collector and a negative pole layer coated on the current collector; the negative electrode layer comprises N heat conduction layers and N +1 active material layers, and the heat conduction layers and the active material layers are arranged at intervals along a first direction; n is an integer, N is more than or equal to 1 and less than or equal to 10, and the first direction is perpendicular to the length direction of the current collector. According to the invention, the heat conducting layer is added in the negative pole piece, so that the heat generated by the negative pole during the quick charge period can be transferred to the copper foil in time, the temperature of the lithium ion battery during the charge and discharge period is reduced, the safety problem and the quick decay of the cycle life of the battery caused by high temperature are avoided, the cycle life of the battery is further improved, and the risk of thermal safety runaway of the battery is reduced.
Description
Technical Field
The invention belongs to the technical field of lithium ion batteries, and particularly relates to a negative electrode plate, a lithium ion battery and a preparation method thereof.
Background
With the continuous development of consumer electronics and new energy automobiles, the technology of lithium ion batteries is also rapidly advanced, and substantial progress is currently made in improving the specific capacity and the cyclicity of the batteries through material optimization, the energy density of the lithium ion batteries is improved from 100Wh/Kg in the early period to 300Wh/Kg in the current high-nickel ternary batteries, so that more and more research interests are currently focused on the reliability and the safety at the battery level. Particularly, the thermal safety of the battery is receiving more and more attention due to the current demand for the quick charging capability of the battery. In the face of the problem of quick charging and heating of the current lithium ion battery, the current mainstream solution still distributes heat during charging in a water cooling and air cooling mode arranged from a PACK level, so that the occurrence of safety accidents can be avoided, the grouping efficiency of battery cells is greatly influenced, and the cost of the battery PACK is increased; in addition, since heat is dissipated through the surface of the battery cell, it is difficult to conduct heat inside the battery cell in time, especially heat generated by lithium ions inserted into the negative electrode during fast charging, which deteriorates the electrochemical performance, especially the cycle life, of the battery.
For example, patent document CN113258037A discloses an overcharge-preventing low-temperature rate negative electrode sheet, in which a composite additive slurry (a charge-preventing additive, a conductive additive, a heat-conducting additive, a dispersant and a solvent) and a negative electrode slurry are mixed and then coated on a current collector or coated on a current collector in a layered manner, or a slurry containing a heat-conducting material is coated on an active material layer, but this structure has a low heat dissipation efficiency of the negative electrode, a heat-generating body in a battery charging and discharging process is coated on the current collector or coated on the current collector in a layered manner, the heat-conducting material is dispersed by the negative electrode material, a continuous heat conductor cannot be formed, and the structure is difficult to efficiently transfer heat generated by the negative electrode material to a copper foil.
Disclosure of Invention
The invention provides a negative pole piece, a lithium ion battery and a preparation method thereof, and aims to solve the problems that in the prior art, negative heat cannot be transferred to the surface of a battery cell through a negative current collector in time, and the multiplying power performance and the cycle life are reduced due to high temperature.
In view of the above technical drawbacks, an object of the present invention is to provide a negative electrode plate, an object of the present invention is to provide a method for manufacturing the negative electrode plate, an object of the present invention is to provide a lithium ion battery assembled with the negative electrode plate, and an object of the present invention is to provide a method for manufacturing the lithium ion battery.
In a first aspect, the invention provides a negative electrode plate, which comprises a current collector and a negative electrode layer coated on the current collector;
the negative electrode layer comprises N heat conduction layers and N +1 active material layers, and the heat conduction layers and the active material layers are alternately stacked along the width direction of the current collector; the thermally conductive layer includes a thermally conductive agent.
In the negative electrode plate, the number of N is adjusted according to actual heat conduction requirements, as an embodiment, N is an integer, and N is greater than or equal to 1 and less than or equal to 10 (for example, 2, 3, 5, 6, 7, 8, 9).
In the above negative electrode sheet, as a preferable embodiment, each width of the active material layer is 3mm to 200mm (for example, 30mm, 60mm, 90mm, 120mm, 150mm, 180 mm);
and/or the width of each heat conduction layer is 0.5mm-10mm (for example: 4mm, 6mm, 8 mm).
In the above negative electrode sheet, as a preferable embodiment, each of the active material layers has a thickness of 40 μm to 300 μm (e.g., 80 μm, 120 μm, 200 μm, 240 μm, 280 μm);
and/or the thickness of each heat conduction layer is the same as that of the active material layer or is 1-20 μm lower than that of the active material layer.
In the above negative electrode sheet, as a preferred embodiment, the mass percentage of the heat conducting agent in the heat conducting layer to the negative electrode active material in the active material layer is 0.5% to 10% (e.g., 1%, 2%, 3%, 5%, 7%, 9%).
In the above negative electrode sheet, as a preferable embodiment, the heat conductive layer contains a heat conductive agent, a first electric conductive agent, and a first binder;
the mass ratio of the heat conducting agent to the first conductive agent to the first binder is (50-90): (5-50): (3-30) and the sum of the mass ratios is equal to 100;
the heat conducting agent comprises one or more of boron nitride, magnesium nitride, aluminum nitride, titanium nitride, zirconium nitride, zinc oxide, aluminum oxide and magnesium oxide.
In the above negative electrode sheet, as a preferred embodiment, the active material layer contains a negative electrode active material, a second conductive agent, and a second binder;
the mass ratio of the negative electrode active material to the second conductive agent to the second binder is (90-98): (0.5-5): (0.5-5) and the sum of the mass ratios is equal to 100.
In the above negative electrode plate, the negative active material includes, but is not limited to, one or more of graphite, hard carbon, mesogenic microspheres, silicon-based material, tin-based material, and graphene.
In the above negative electrode plate, the first conductive agent and the second conductive agent are not limited, and may be conductive agents commonly used in the negative electrode plate manufacturing process, as a preferred embodiment, the first conductive agent and the second conductive agent respectively include one or more of conductive carbon black, acetylene black, ketjen black, conductive graphite, conductive carbon fiber, carbon nanotube, graphene, metal powder, or carbon fiber, and the first conductive agent and the second conductive agent may be the same or different;
in the above negative electrode plate, the first binder and the second binder are not limited, and may be binders commonly used in a negative electrode plate manufacturing process, the first binder and the second binder respectively include one or more of styrene butadiene latex (SBR), carboxymethyl cellulose (CMC), polyacrylic acid (PAA), lithium polyacrylate (PAA-Li), sodium polyacrylate (PAA-Na), polyvinyl alcohol (PVA), polyvinylidene fluoride (PVDF), and sodium carboxymethyl cellulose, and the first binder and the second binder may be the same or different.
In a second aspect, the invention also provides a preparation method of the negative electrode plate, which comprises the following steps,
preparing heat-conducting slurry: dissolving a heat conducting agent, a first conductive agent and a first binder in deionized water or an alcohol solvent according to a ratio, and uniformly stirring to obtain heat conducting slurry;
preparing active material slurry: dissolving a negative electrode active material, a second conductive agent and a second binder in deionized water according to a ratio, and uniformly stirring to obtain active material slurry;
preparing a negative pole piece: and coating the heat conduction slurry and the active material slurry on a current collector according to a designed negative electrode layer structure, and drying, cold pressing and cutting to obtain the negative electrode piece.
In the above production method, as a preferred embodiment, the coating is performed by extrusion coating; the coating apparatus is a conventional extrusion coater.
The coating is single-side coating or double-side coating;
the alcohol solvent can be methanol solution, ethanol solution, isopropanol solution, and n-butanol solution;
the mass fraction of the methanol solution, ethanol solution, isopropanol solution, and n-butanol solution is preferably 50-100% (e.g., 60%, 70%, 80%, 90%).
The drying, cold pressing and cutting are all conventional methods for preparing the negative pole piece in the field.
In a third aspect, the invention further provides a lithium ion battery, which comprises a positive pole piece, a diaphragm, electrolyte and the negative pole piece.
The lithium ion battery also comprises a shell.
In a fourth aspect, the invention also provides a preparation method of the lithium ion battery, which comprises the following steps,
and sequentially laminating the positive pole piece, the diaphragm and the negative pole piece, winding the positive pole piece, the diaphragm and the negative pole piece into a battery core, placing the battery core into an aluminum-plastic film, drying the battery core, injecting electrolyte, and then carrying out vacuum packaging, standing, formation and shaping to obtain the lithium ion battery.
In the invention, drying, vacuum packaging, standing, formation and shaping are all conventional methods for preparing the lithium ion battery in the field.
Compared with the prior art, the invention has at least one of the following beneficial effects:
1. the invention provides a negative pole piece, which comprises a current collector and a negative pole layer coated on the current collector; the negative electrode layer comprises N heat conduction layers and N +1 active material layers, and the heat conduction layers and the active material layers are arranged at intervals along a first direction; n is an integer, N is more than or equal to 1 and less than or equal to 10, and the first direction is perpendicular to the length direction of the current collector (the heat conduction layers and the active material layers are alternately stacked along the width direction of the current collector). According to the invention, the heat conducting layer is added in the negative pole piece, so that the heat generated by the negative pole during the quick charge period can be transferred to the copper foil in time, the temperature of the lithium ion battery during the charge and discharge period is reduced, the safety problem and the quick decay of the cycle life of the battery caused by high temperature are avoided, the cycle life of the battery is further improved, and the risk of thermal safety runaway of the battery is reduced.
2. The conductive agent and the heat conducting agent in the heat conducting layer can enable the heat conducting layer to have better liquid retention capacity, store more electrolyte and provide more lithium ion channels for the negative electrode, and the lithium ion channels are parallel to the lithium ion rapid conduction surface of the negative electrode graphite, so that the conduction of lithium ions in the negative electrode active material can be accelerated, and the integral multiplying power capacity of the battery cell is improved.
3. According to the invention, the heat generated during the quick charge of the battery cell is reduced on the pole piece layer, the partial cooling structure of the PACK layer is reduced, the space utilization rate and the energy density of a battery system are improved, and the cost is reduced.
Drawings
FIG. 1 is a cross-sectional view in the width direction of a positive electrode sheet according to the present invention;
FIG. 2 is a top view of the positive electrode plate of the present invention.
Description of the drawings: 1-current collector, 2-heat conducting layer and 3-active substance layer.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The embodiments of the present invention are implemented on the premise of the technical scheme of the present invention, and detailed embodiments and processes are given, but the scope of the present invention is not limited to the following embodiments, and the following embodiments do not indicate process parameters of specific conditions, and generally follow conventional conditions.
The endpoints of the ranges and any values disclosed in the present application are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual values, and between the individual values may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.
In the present invention, all numerical values relating to amounts of components are "parts by weight" throughout, unless otherwise specified and/or indicated. The process parameters for the following examples, without specifying the particular conditions, are generally in accordance with conventional conditions.
The following provides a more detailed description of the preparation method of the positive electrode plate and the lithium ion battery of the present invention through the following examples, which are given only for illustrating the present invention and are not intended to limit the scope of the present invention. The following examples are provided as the basis for further modifications and applications by those skilled in the art and are not to be construed as limiting the invention in any way.
The positive pole piece, the diaphragm and the electrolyte in the following examples and comparative examples are prepared by the following methods:
the preparation method of the positive pole piece comprises the following steps:
mixing positive active material LiNi 0.8 Co 0.1 Mn 0.1 O 2 The conductive carbon black Super-P and the adhesive PVDF are mixed according to the weight ratio of 97.6:1.3:1.1, fully stirring in an N-methylpyrrolidone NMP solvent system by a vacuum stirrer to obtain anode slurry; and coating the positive electrode slurry on two surfaces of a 12 mu m Al foil substrate, and sequentially drying, cold pressing, slitting and cutting to obtain the positive electrode piece.
The preparation method of the diaphragm comprises the following steps:
the separator was obtained by coating a 2 μm alumina ceramic layer on each side of a separator substrate made of Polyethylene (PE) having a thickness of 8 μm, and a 2.5mg binder polyvinylidene fluoride (PVDF) on each side coated with the ceramic layer, and drying the coating.
The preparation method of the electrolyte comprises the following steps:
mixing Ethylene Carbonate (EC), ethyl Methyl Carbonate (EMC) and dimethyl carbonate (DMC) according to a volume ratio of 3:3:4 to obtain an organic solvent, and then fully drying the LiPF 6 Dissolving the mixture in the mixed organic solvent to prepare electrolyte with the concentration of 1 mol/L.
Example 1
The embodiment provides a preparation method of a negative pole piece, which comprises the following steps:
graphite, a Super-P conductive agent, styrene-butadiene latex and sodium carboxymethyl cellulose are mixed according to a mass ratio of 96.5:1:1.2:1.3, dissolving in deionized water, fully stirring and uniformly mixing to obtain active substance slurry;
aluminum nitride, conductive carbon black, styrene-butadiene latex and sodium carboxymethylcellulose are mixed according to a mass ratio of 80:15:3: dissolving the mixture 2 in an ethanol solution (the mass fraction is 95 percent), and fully stirring and uniformly mixing to obtain heat-conducting slurry;
coating the active material slurry and the heat conduction slurry on the surface of a negative current collector 1 (6 mu m copper foil) through an extrusion coating machine, and drying, cold pressing and cutting the mixture in sequence to obtain the negative pole piece.
In the negative electrode plate prepared in this embodiment, the thickness of each active material layer 3 is 160 μm, the width is 15mm, and the thickness of each heat conduction layer 2 is 160 μm, and the width is 2mm. The negative pole piece comprises 3 heat conduction layers and 4 active material layers. In the negative pole piece, the mass ratio of the aluminum nitride to the graphite is 3%.
The embodiment also provides a preparation method of the lithium ion battery, which comprises the following steps:
stacking the positive pole piece, the isolating film and the negative pole piece in sequence to enable the isolating film to be positioned between the positive pole piece and the negative pole piece to play an isolating role, and then winding to obtain a bare cell; welding the qualified bare cell on the top cover through a tab, placing the qualified bare cell in an outer packaging shell, drying the bare cell, injecting electrolyte, and performing vacuum packaging, standing, formation, shaping and other procedures to obtain the lithium ion battery with the capacity of about 5000mAh.
Example 2
The embodiment provides a preparation method of a negative pole piece, which comprises the following steps:
this example is different from example 1 in that the negative active material was 95% by weight of graphite +5% by weight of silica (S0221-Lorentidede), and the rest was the same as example 1.
In the negative electrode plate prepared in this embodiment, the thickness of each active material layer is 140 μm, the width is 15mm, and the thickness of each heat conduction layer is 140 μm, and the width is 2mm. The negative pole piece comprises 3 heat conduction layers and 4 active material layers.
The embodiment also provides a preparation method of the lithium ion battery, which comprises the following steps:
stacking the positive pole piece, the isolating film and the negative pole piece in sequence to enable the isolating film to be positioned between the positive pole piece and the negative pole piece to play an isolating role, and then winding to obtain a bare cell; welding the qualified bare cell on the top cover through a tab, placing the qualified bare cell in an outer packaging shell, drying the bare cell, injecting electrolyte, and performing vacuum packaging, standing, formation, shaping and other procedures to obtain the lithium ion battery with the capacity of about 5000mAh.
Example 3
The embodiment provides a preparation method of a negative pole piece, which comprises the following steps:
this example is different from example 1 in that titanium nitride is used as a heat conductive agent, and the rest is the same as example 1.
In the negative electrode plate prepared in this embodiment, the thickness of each active material layer 3 is 160 μm, the width is 15mm, and the thickness of each heat conduction layer 2 is 160 μm, and the width is 2mm. The negative pole piece comprises 3 heat conduction layers and 4 active material layers.
The embodiment also provides a preparation method of the lithium ion battery, which comprises the following steps:
stacking the positive pole piece, the isolating film and the negative pole piece in sequence to enable the isolating film to be positioned between the positive pole piece and the negative pole piece to play an isolating role, and then winding to obtain a bare cell; welding the qualified bare cell on the top cover through a tab, placing the qualified bare cell in an outer packaging shell, drying the bare cell, injecting electrolyte, and performing vacuum packaging, standing, formation, shaping and other procedures to obtain the lithium ion battery with the capacity of about 5000mAh.
Example 4
In this example, the difference in the production method from example 1 is that boron nitride was used as the heat conductive agent, and the rest is the same as example 1.
In the negative electrode plate prepared in this embodiment, the thickness of each active material layer 3 is 160 μm, the width is 15mm, and the thickness of each heat conduction layer 2 is 160 μm, and the width is 2mm. The negative pole piece comprises 3 heat conduction layers and 4 active material layers.
The embodiment also provides a preparation method of the lithium ion battery, which comprises the following steps:
stacking the positive pole piece, the isolating film and the negative pole piece in sequence to enable the isolating film to be positioned between the positive pole piece and the negative pole piece to play an isolating role, and then winding to obtain a bare cell; welding the qualified bare cell on the top cover through a tab, placing the qualified bare cell in an outer packaging shell, drying the bare cell, injecting electrolyte, and performing vacuum packaging, standing, formation, shaping and other procedures to obtain the lithium ion battery with the capacity of about 5000mAh.
Example 5
Compared with example 1, the preparation method of the present embodiment is different in that the preparation method of the thermal conductive paste of the present embodiment is as follows: aluminum nitride, conductive carbon black, graphene, styrene-butadiene latex and sodium carboxymethyl cellulose are mixed according to a mass ratio of 80:14:3:1.6:1.4 in deionized water, and fully stirring and uniformly mixing to obtain the heat-conducting slurry, wherein the rest is the same as that in the embodiment 1.
In the negative electrode plate prepared in this embodiment, the thickness of each active material layer 3 is 160 μm, the width is 15mm, and the thickness of each heat conduction layer 2 is 160 μm, and the width is 2mm. The negative pole piece comprises 3 heat conduction layers and 4 active material layers.
The embodiment also provides a preparation method of the lithium ion battery, which comprises the following steps:
stacking the positive pole piece, the isolating film and the negative pole piece in sequence to enable the isolating film to be positioned between the positive pole piece and the negative pole piece to play an isolating role, and then winding to obtain a bare cell; welding the qualified bare cell on the top cover through a tab, placing the qualified bare cell in an outer packaging shell, drying the bare cell, injecting electrolyte, and performing vacuum packaging, standing, formation, shaping and other procedures to obtain the lithium ion battery with the capacity of about 5000mAh.
Comparative example 1
The comparative example provides a preparation method of a negative pole piece, which comprises the following steps:
graphite, a conductive agent, styrene-butadiene latex and sodium carboxymethylcellulose are mixed according to a mass ratio of 96.5:1:1.2: dissolving the active substance slurry in the ethanol solution (the mass fraction is 95%) according to the proportion of 1.3, and fully stirring and uniformly mixing to obtain active substance slurry;
and coating the active substance slurry on the surface of a negative current collector (6-micron copper foil), and drying, cold pressing and cutting the negative current collector in sequence to obtain the negative pole piece.
In the negative electrode sheet prepared in this comparative example, the thickness of the active material layer was 160 μm, and the width was 66mm.
The comparative example also provides a method of making a lithium ion battery, comprising the steps of,
stacking the positive pole piece, the isolating film and the negative pole piece in sequence to enable the isolating film to be positioned between the positive pole piece and the negative pole piece to play an isolating role, and then winding to obtain a bare cell; welding the qualified bare cell on the top cover through a tab, placing the qualified bare cell in an outer packaging shell, drying the bare cell, injecting electrolyte, and performing vacuum packaging, standing, formation, shaping and other procedures to obtain the lithium ion battery with the capacity of about 5000mAh.
Comparative example 2
The comparative example provides a preparation method of a negative pole piece, which comprises the following steps:
compared with the comparative example 1, the preparation method of the negative electrode active material is different in that graphite +5% of silicon carbon is adopted as the negative electrode active material, and the rest is the same as the comparative example 1.
In the negative electrode sheet prepared in this comparative example, the thickness of the active material layer was 140 μm, and the width was 66mm.
The comparative example also provides a method of making a lithium ion battery, comprising the steps of,
stacking the positive pole piece, the isolating film and the negative pole piece in sequence to enable the isolating film to be positioned between the positive pole piece and the negative pole piece to play an isolating role, and then winding to obtain a bare cell; welding the qualified bare cell on the top cover through a tab, placing the qualified bare cell in an outer packaging shell, drying the bare cell, injecting electrolyte, and performing vacuum packaging, standing, formation, shaping and other procedures to obtain the lithium ion battery with the capacity of about 5000mAh.
Comparative example 3
The comparative example provides a preparation method of a negative pole piece, which comprises the following steps:
compared with the example 1, the preparation method of the present invention is different in that after the active paste and the thermal conductive paste are prepared, the active material paste and the thermal conductive paste are uniformly mixed and then coated on the negative electrode current collector, and the other steps are the same as those of the example 1.
The comparative example also provides a method of making a lithium ion battery, comprising the steps of,
stacking the positive pole piece, the isolating film and the negative pole piece in sequence to enable the isolating film to be positioned between the positive pole piece and the negative pole piece to play an isolating role, and then winding to obtain a bare cell; welding the qualified bare cell on the top cover through a tab, placing the qualified bare cell in an outer packaging shell, drying the bare cell, injecting electrolyte, and performing vacuum packaging, standing, formation, shaping and other procedures to obtain the lithium ion battery with the capacity of about 5000mAh.
Test example
The lithium ion batteries prepared in examples 1 to 5 and comparative examples 1 to 3 were tested for charge rate, cell surface temperature rise, and cycle life.
The method for testing the charging multiplying power comprises the following steps: 2C capacity: at 25 ℃, the cell was discharged to 2.75V at 1C, left to stand for 1 hour, charged to 4.2V at 2C, left to stand for 1 hour, and finally discharged to 2.75V at 2C and the 2C discharge capacity was measured.
The 2C charge rate is the 2C capacity divided by the 1C capacity.
3C capacity: at 25 ℃, the cell was discharged to 2.75V at 1C, left to stand for 1 hour, charged to 4.2V at 3C, left to stand for 1 hour, and finally discharged to 2.75V at 3C and the 3C discharge capacity was measured.
The 3C charge rate is the 3C capacity divided by the 1C capacity;
the test method for 500 times of cycle life comprises the following steps: the cell was discharged at 25 ℃ to 2.75V at 1C, left to stand for 1 hour, charged at 1C to 4.2V, left to stand for 1 hour, and finally discharged at 1C to 2.75V, and the 1C discharge capacity (i.e., the first cycle capacity) was measured, and the first cycle capacity was divided by the capacity after 500 cycles.
The specific test results are shown in the following table:
from the test summary results in the table, when the heat conduction layer is added to the negative electrode plate according to the method of the present invention, the temperature rise of the lithium ion battery during charging and discharging can be reduced, the rate retention rate of the lithium ion battery can be increased, and the cycle life of the battery can be improved. In addition, as can be seen from the comparison of data between example 1 and comparative example 3, the negative electrode sheet prepared by coating the heat conducting agent and the active slurry on the negative current collector has the advantages of rate retention, temperature rise and 500-time cycle performance, which are different from the negative electrode sheet prepared by adding the heat conducting layer between the active material layers according to the method of the present invention.
The above description is only exemplary of the invention and should not be taken as limiting the invention, as any modification, equivalent replacement, or improvement made within the spirit and principle of the invention is intended to be covered by the appended claims.
Claims (10)
1. The negative pole piece is characterized by comprising a current collector and a negative pole layer coated on the current collector;
the negative electrode layer comprises N heat conduction layers and N +1 active material layers, and the heat conduction layers and the active material layers are alternately stacked along the width direction of the current collector; the thermally conductive layer includes a thermally conductive agent.
2. The negative electrode plate as claimed in claim 1, wherein N is an integer of 1. Ltoreq. N.ltoreq.10.
3. The negative electrode tab according to claim 1, wherein each of the active material layers has a width of 3mm to 200mm;
and/or the width of each heat conduction layer is 0.5mm-10mm.
4. The negative electrode tab according to claim 1, wherein each of the active material layers has a thickness of 40 μm to 300 μm;
and/or the thickness of each heat conduction layer is the same as that of the active material layer or is 1-20 μm lower than that of the active material layer.
5. The negative electrode plate of claim 1, wherein the heat conducting layer contains 0.5-10% by mass of the negative electrode active material in the active material layer of the heat conducting layer;
the thermally conductive layer includes a thermally conductive agent, a first electrically conductive agent, and a first binder;
the mass ratio of the heat conducting agent to the first conductive agent to the first binder is (50-90): (5-50): (3-30) and the sum of the mass ratios is equal to 100;
the heat conducting agent comprises one or more of boron nitride, magnesium nitride, aluminum nitride, titanium nitride, zirconium nitride, zinc oxide, aluminum oxide and magnesium oxide.
6. The negative electrode sheet according to claim 1, wherein the active material layer contains a negative electrode active material, a second conductive agent, and a second binder;
the mass ratio of the negative electrode active material to the second conductive agent to the second binder is (90-98): (0.5-5): (0.5-5) and the sum of the mass ratios is equal to 100.
7. A preparation method of the negative pole piece of any one of claims 1 to 6, which is characterized by comprising the following steps,
preparing heat-conducting slurry: dissolving a heat conducting agent, a first conductive agent and a first binder in deionized water or an alcohol solvent according to a ratio, and uniformly stirring to obtain heat conducting slurry;
preparing active material slurry: dissolving a negative electrode active material, a second conductive agent and a second binder in deionized water according to a ratio, and uniformly stirring to obtain active material slurry;
preparing a negative pole piece: and coating the heat conduction slurry and the active material slurry on a current collector according to a designed negative electrode layer structure, and drying, cold pressing and cutting to obtain the negative electrode piece.
8. The preparation method of the negative pole piece according to claim 7, wherein the coating mode is extrusion coating;
the coating is single-side coating or double-side coating;
the alcohol solvent is one or more of methanol solution, ethanol solution, isopropanol solution and n-butanol solution.
9. A lithium ion battery, comprising a positive electrode plate, a diaphragm, an electrolyte, and the negative electrode plate of any one of claims 1 to 6 or the negative electrode plate prepared by the method of claim 7 or 8.
10. A method for preparing the lithium ion battery of claim 9, comprising the steps of,
and (2) sequentially laminating the positive pole piece, the diaphragm, the negative pole piece according to any one of claims 1 to 6 or the negative pole piece prepared by the method according to claim 7 or 8, winding the laminated positive pole piece and the diaphragm into a battery cell, placing the battery cell into an aluminum-plastic film, drying the battery cell, injecting electrolyte, and then carrying out vacuum packaging, standing, formation and shaping to obtain the lithium ion battery.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009043515A (en) * | 2007-08-08 | 2009-02-26 | Hitachi Maxell Ltd | Electrode for battery, method of manufacturing the same, and battery having electrode for battery |
| CN113036075A (en) * | 2021-02-26 | 2021-06-25 | 珠海冠宇电池股份有限公司 | Pole piece and battery cell |
| CN113258037A (en) * | 2021-05-28 | 2021-08-13 | 陕西煤业化工技术研究院有限责任公司 | Overcharge-prevention low-temperature-rate negative pole piece, manufacturing method thereof and lithium ion battery based on overcharge-prevention low-temperature-rate negative pole piece |
| CN114203962A (en) * | 2021-12-13 | 2022-03-18 | 珠海冠宇动力电池有限公司 | Pole piece, battery core and battery |
| CN114207872A (en) * | 2019-08-09 | 2022-03-18 | 株式会社半导体能源研究所 | Negative electrode, secondary battery, and solid-state secondary battery |
| CN216849989U (en) * | 2021-11-10 | 2022-06-28 | 宁德时代新能源科技股份有限公司 | Laminated cell, single battery, battery and power utilization device |
| WO2022181489A1 (en) * | 2021-02-25 | 2022-09-01 | 三洋電機株式会社 | Negative electrode for nonaqueous electrolyte secondary batteries, and nonaqueous electrolyte secondary battery |
| CN217768423U (en) * | 2022-02-10 | 2022-11-08 | 宁德时代新能源科技股份有限公司 | Negative electrode plate, secondary battery, battery module, battery pack and electric device |
-
2022
- 2022-12-21 CN CN202211655534.9A patent/CN115832202B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009043515A (en) * | 2007-08-08 | 2009-02-26 | Hitachi Maxell Ltd | Electrode for battery, method of manufacturing the same, and battery having electrode for battery |
| CN114207872A (en) * | 2019-08-09 | 2022-03-18 | 株式会社半导体能源研究所 | Negative electrode, secondary battery, and solid-state secondary battery |
| WO2022181489A1 (en) * | 2021-02-25 | 2022-09-01 | 三洋電機株式会社 | Negative electrode for nonaqueous electrolyte secondary batteries, and nonaqueous electrolyte secondary battery |
| CN113036075A (en) * | 2021-02-26 | 2021-06-25 | 珠海冠宇电池股份有限公司 | Pole piece and battery cell |
| CN113258037A (en) * | 2021-05-28 | 2021-08-13 | 陕西煤业化工技术研究院有限责任公司 | Overcharge-prevention low-temperature-rate negative pole piece, manufacturing method thereof and lithium ion battery based on overcharge-prevention low-temperature-rate negative pole piece |
| CN216849989U (en) * | 2021-11-10 | 2022-06-28 | 宁德时代新能源科技股份有限公司 | Laminated cell, single battery, battery and power utilization device |
| CN114203962A (en) * | 2021-12-13 | 2022-03-18 | 珠海冠宇动力电池有限公司 | Pole piece, battery core and battery |
| CN217768423U (en) * | 2022-02-10 | 2022-11-08 | 宁德时代新能源科技股份有限公司 | Negative electrode plate, secondary battery, battery module, battery pack and electric device |
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| CN115832202B (en) | 2023-09-29 |
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