CN116779768A - Composite electrode plate and preparation method thereof, solid-state battery and preparation method thereof - Google Patents
Composite electrode plate and preparation method thereof, solid-state battery and preparation method thereof Download PDFInfo
- Publication number
- CN116779768A CN116779768A CN202311063796.0A CN202311063796A CN116779768A CN 116779768 A CN116779768 A CN 116779768A CN 202311063796 A CN202311063796 A CN 202311063796A CN 116779768 A CN116779768 A CN 116779768A
- Authority
- CN
- China
- Prior art keywords
- pole piece
- lithium salt
- solvent
- electrode plate
- salt solution
- 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.)
- Granted
Links
- 239000002131 composite material Substances 0.000 title claims abstract description 52
- 238000002360 preparation method Methods 0.000 title claims abstract description 41
- 229910003002 lithium salt Inorganic materials 0.000 claims abstract description 90
- 159000000002 lithium salts Chemical class 0.000 claims abstract description 90
- 239000012266 salt solution Substances 0.000 claims abstract description 69
- 239000002904 solvent Substances 0.000 claims abstract description 63
- 239000000203 mixture Substances 0.000 claims abstract description 41
- 238000002156 mixing Methods 0.000 claims abstract description 38
- 239000003792 electrolyte Substances 0.000 claims abstract description 37
- 239000011248 coating agent Substances 0.000 claims abstract description 30
- 238000000576 coating method Methods 0.000 claims abstract description 30
- 239000011230 binding agent Substances 0.000 claims abstract description 25
- 238000010438 heat treatment Methods 0.000 claims abstract description 21
- 238000005303 weighing Methods 0.000 claims abstract description 18
- 229910052744 lithium Inorganic materials 0.000 claims abstract description 16
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims abstract description 13
- 239000000853 adhesive Substances 0.000 claims abstract description 9
- 230000001070 adhesive effect Effects 0.000 claims abstract description 9
- RXGUIWHIADMCFC-UHFFFAOYSA-N 2-Methylpropyl 2-methylpropionate Chemical compound CC(C)COC(=O)C(C)C RXGUIWHIADMCFC-UHFFFAOYSA-N 0.000 claims description 26
- 238000003756 stirring Methods 0.000 claims description 16
- XUPYJHCZDLZNFP-UHFFFAOYSA-N butyl butanoate Chemical compound CCCCOC(=O)CCC XUPYJHCZDLZNFP-UHFFFAOYSA-N 0.000 claims description 10
- 238000004519 manufacturing process Methods 0.000 claims description 10
- IMNFDUFMRHMDMM-UHFFFAOYSA-N N-Heptane Chemical compound CCCCCCC IMNFDUFMRHMDMM-UHFFFAOYSA-N 0.000 claims description 9
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 9
- 239000007788 liquid Substances 0.000 claims description 7
- IAHFWCOBPZCAEA-UHFFFAOYSA-N succinonitrile Chemical compound N#CCCC#N IAHFWCOBPZCAEA-UHFFFAOYSA-N 0.000 claims description 7
- FUSUHKVFWTUUBE-UHFFFAOYSA-N buten-2-one Chemical compound CC(=O)C=C FUSUHKVFWTUUBE-UHFFFAOYSA-N 0.000 claims description 6
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 claims description 6
- GMQVFHZSXKJCIV-UHFFFAOYSA-N 2,2,2-trifluoro-n-(2,2,2-trifluoroacetyl)acetamide Chemical compound FC(F)(F)C(=O)NC(=O)C(F)(F)F GMQVFHZSXKJCIV-UHFFFAOYSA-N 0.000 claims description 5
- 229910003473 lithium bis(trifluoromethanesulfonyl)imide Inorganic materials 0.000 claims description 5
- QSZMZKBZAYQGRS-UHFFFAOYSA-N lithium;bis(trifluoromethylsulfonyl)azanide Chemical group [Li+].FC(F)(F)S(=O)(=O)[N-]S(=O)(=O)C(F)(F)F QSZMZKBZAYQGRS-UHFFFAOYSA-N 0.000 claims description 5
- 229920005569 poly(vinylidene fluoride-co-hexafluoropropylene) Polymers 0.000 claims description 5
- 229910013870 LiPF 6 Inorganic materials 0.000 claims description 4
- 101150058243 Lipf gene Proteins 0.000 claims description 4
- 229910018130 Li 2 S-P 2 S 5 Inorganic materials 0.000 claims description 3
- 229920000459 Nitrile rubber Polymers 0.000 claims description 3
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 claims description 3
- 239000002033 PVDF binder Substances 0.000 claims description 3
- HIHIPCDUFKZOSL-UHFFFAOYSA-N ethenyl(methyl)silicon Chemical compound C[Si]C=C HIHIPCDUFKZOSL-UHFFFAOYSA-N 0.000 claims description 3
- 229920002981 polyvinylidene fluoride Polymers 0.000 claims description 3
- 238000003825 pressing Methods 0.000 claims description 3
- 229920002379 silicone rubber Polymers 0.000 claims description 3
- 239000004945 silicone rubber Substances 0.000 claims description 3
- 239000008096 xylene Substances 0.000 claims description 3
- 239000002002 slurry Substances 0.000 abstract description 21
- 239000011149 active material Substances 0.000 abstract description 4
- 230000008961 swelling Effects 0.000 abstract description 4
- 238000007711 solidification Methods 0.000 abstract 1
- 230000008023 solidification Effects 0.000 abstract 1
- 239000012528 membrane Substances 0.000 description 18
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 17
- 239000006258 conductive agent Substances 0.000 description 9
- 239000007787 solid Substances 0.000 description 9
- 239000002134 carbon nanofiber Substances 0.000 description 7
- 238000001035 drying Methods 0.000 description 7
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 6
- 150000002500 ions Chemical class 0.000 description 5
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 4
- 239000011888 foil Substances 0.000 description 4
- 239000007774 positive electrode material Substances 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 239000007773 negative electrode material Substances 0.000 description 3
- HJTVQHVGMGKONQ-LUZURFALSA-N Curcumin II Natural products C1=C(O)C(OC)=CC(\C=C\C(=O)CC(=O)\C=C\C=2C=CC(O)=CC=2)=C1 HJTVQHVGMGKONQ-LUZURFALSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 239000006183 anode active material Substances 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000006255 coating slurry Substances 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 238000005338 heat storage Methods 0.000 description 1
- 229910052738 indium Inorganic materials 0.000 description 1
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Landscapes
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention relates to a composite electrode plate and a preparation method thereof, a solid-state battery and a preparation method thereof, and the preparation method of the composite electrode plate comprises the following steps: s1, weighing a lithium guide solvent and lithium salt, coating a lithium salt solution obtained by mixing on a first pole piece, and forming an intermediate layer on the surface of the first pole piece after solidification; s2, adding the electrolyte and the first binder into a first solvent, mixing to obtain a mixture, and coating the mixture on the intermediate layer to obtain an intermediate pole piece; and S3, performing heating treatment on the middle electrode plate to obtain the composite electrode plate. The lithium salt solution is coated on the first pole piece by mixing the lithium conducting solvent and the lithium salt, and the first solvent in the electrolyte slurry is isolated through the intermediate layer, so that the phenomena of reduced adhesive force and poor pole piece performance caused by swelling of the first adhesive in the first pole piece caused by the first solvent are avoided; in addition, the lithium salt solution is completely dissolved and immersed in the first pole piece to serve as an ion passage in the first pole piece, so that the performance of the active material is ensured.
Description
Technical Field
The invention belongs to the technical field of solid-state battery manufacturing, and particularly relates to a composite electrode plate and a preparation method thereof, a solid-state battery and a preparation method thereof.
Background
Based on the requirements of high energy density and high safety of the battery, all-solid-state batteries become a research hotspot. It is largely classified into an oxide all-solid battery, a polymer all-solid battery, and a sulfide all-solid battery, which are the main systems due to their excellent ionic conductivity and good mechanical flexibility. However, at present, the sulfide all-solid-state battery is still in the assembly stage of the pressure die, only a few enterprises try small-capacity soft package assembly, and the mechanical property of the sulfide electrolyte membrane is mainly used for limiting the assembly mode of the soft package, the thin sulfide electrolyte membrane is difficult to self-support (if the thicker sulfide electrolyte membrane seriously affects the energy density of the battery), the thin sulfide electrolyte membrane needs to be supported by a base membrane, and the thin sulfide all-solid-state battery is firstly transferred to a pole piece to remove the base membrane and then laminated in the subsequent assembly, so that the complicated assembly process and the extremely low production efficiency are caused. In addition, such a large solid-solid interface forms a large contact resistance, directly affecting the capacity exertion of the battery.
Therefore, a process of directly coating the sulfide electrolyte membrane on the surface of the pole piece is explored, and the interface contact resistance is reduced, and meanwhile, the subsequent assembly process flow is simplified. However, the process has a great problem that when the surface of the pole piece is coated with the sulfide electrolyte membrane, the solvent in the sulfide electrolyte slurry can permeate into the pole piece layer, and at the moment, the binder in the pole piece layer can swell, namely, the binder is dissolved and redistributed, so that the active material and the current collector of the pole piece layer are separated due to uneven distribution of the binder, and the electrical performance of the battery is directly deteriorated.
Disclosure of Invention
In order to solve the technical problems, the lithium salt solution is obtained by mixing the lithium-conducting solvent and the lithium salt and is coated on the first pole piece, the first solvent in the electrolyte slurry is isolated through the intermediate layer, and the phenomena of reduced adhesive force and poor pole piece performance caused by swelling of the first binder in the first pole piece caused by the first solvent are avoided; in addition, the lithium salt solution is completely dissolved and immersed in the first pole piece to serve as an ion passage in the first pole piece, so that the performance of the active material is ensured.
The technical scheme for solving the technical problems is as follows: the preparation method of the composite electrode slice comprises the following preparation steps:
s1, weighing a lithium guide solvent and lithium salt, mixing to obtain a lithium salt solution, coating the lithium salt solution on a first pole piece, and forming an intermediate layer on the surface of the first pole piece after the lithium salt solution on the first pole piece is solidified;
s2, adding the electrolyte and the first binder into a first solvent, mixing and stirring to obtain a mixture, and coating the mixture on the intermediate layer to obtain an intermediate pole piece;
and S3, carrying out heating treatment on the middle electrode plate, and obtaining the composite electrode plate after the middle layer is partially or completely soaked into the first electrode plate.
The invention also provides a preparation method of the solid-state battery, which comprises the following preparation steps:
a1, weighing a lithium guide solvent and lithium salt, mixing to obtain lithium salt solution, respectively coating the lithium salt solution on an anode electrode plate and a cathode electrode plate, and respectively forming an anode intermediate layer and a cathode intermediate layer on the surfaces of the anode electrode plate and the cathode electrode plate after the lithium salt solution is solidified;
a2, adding the electrolyte and the first binder into the first solvent, mixing and stirring to obtain a mixture, respectively coating the mixture on the positive electrode intermediate layer and the negative electrode intermediate layer, solidifying the mixture on the positive electrode intermediate layer to obtain a positive electrode intermediate pole piece, and solidifying the mixture on the negative electrode intermediate layer to obtain a negative electrode intermediate pole piece;
a3, assembling the positive electrode middle pole piece and the negative electrode middle pole piece into a full battery;
a4, carrying out heating treatment on the full battery, wherein the positive electrode intermediate layer is partially or completely infiltrated into the positive electrode plate to obtain a positive electrode composite plate, and the negative electrode intermediate layer is partially or completely infiltrated into the negative electrode plate to obtain a negative electrode composite plate;
and A5, applying pressure to the heated full battery to tightly combine the positive electrode composite pole piece and the negative electrode composite pole piece.
On the basis of the technical scheme, the invention can be improved as follows.
Preferably, the lithium-conducting solvent is in a liquid state by heating, and then the lithium-conducting solvent and the lithium salt are weighed and mixed to obtain a lithium salt solution; or mixing the lithium-conducting solvent with lithium salt, and then heating, stirring and uniformly mixing to obtain a lithium salt solution; and coating the lithium salt solution on a first electrode plate (an anode electrode plate or a cathode electrode plate), wherein the temperature of the lithium salt solution on the first electrode plate (the anode electrode plate or the cathode electrode plate) is gradually reduced to room temperature, so that after the lithium salt solution is gradually solidified, a corresponding intermediate layer is formed on the surfaces of the first electrode plate, the anode electrode plate or the cathode electrode plate.
Preferably, the electrolyte and the first binder are added into the first solvent, the mixture is obtained after mixing and stirring, the mixture is coated on the middle layer, after the first solvent volatilizes, the mixture on the middle layer is solidified, a layer of electrolyte membrane is formed on the middle layer, and the middle pole piece is obtained. When the mixture is coated on the positive electrode intermediate layer and the negative electrode intermediate layer, the mixture on the positive electrode intermediate layer and the negative electrode intermediate layer is solidified after the first solvent volatilizes, and a layer of electrolyte membrane is formed on the positive electrode intermediate layer and the negative electrode intermediate layer. In the step A3, when the full battery is assembled, the electrolyte membrane on the positive electrode middle layer is attached to the electrolyte membrane on the negative electrode middle layer, and the positive electrode plate and the negative electrode plate are respectively positioned on two sides of the full battery. The positive electrode plate can be realized by adopting the positive electrode plate of the existing liquid battery, and the negative electrode plate can be realized by adopting the negative electrode plate of the existing liquid battery.
In step A5, opposite pressure is applied to the two ends of the full cell, the pressure direction is generally perpendicular to the front surface of the positive electrode plate or the negative electrode plate, and the positive electrode composite plate and the negative electrode composite plate are forced to approach each other by the pressure, so that the positive electrode plate and the electrolyte membrane, the negative electrode plate and the electrolyte membrane, and the positive electrode composite plate and the negative electrode composite plate are tightly combined. The pressure exerted on the full cell may be between 200MPa and 1000 MPa.
Preferably, the lithium-conducting solvent is at least one of succinonitrile and bis-trifluoroacetamide.
Preferably, the concentration of the lithium salt in the lithium salt solution is 0.5mol/L to 2mol/L.
Preferably, the first pole piece is a positive pole piece or a negative pole piece, and the first pole piece can be realized by adopting the positive pole piece or the negative pole piece of the existing liquid battery.
Preferably, (1) preparation of a positive electrode composite electrode sheet:
S1A, preparing a first pole piece of the positive electrode;
S2A, weighing a lithium guide solvent and lithium salt, mixing to obtain a lithium salt solution, coating the lithium salt solution on a first pole piece of an anode, and forming an intermediate layer on the surface of the first pole piece after the lithium salt solution on the first pole piece is solidified;
S3A, repeating the steps S2 and S3 to obtain a positive composite electrode plate;
(2) Preparation of a negative electrode composite electrode plate:
S1A, preparing a first pole piece of a negative electrode;
S2A, weighing a lithium-conducting solvent and lithium salt, mixing to obtain a lithium salt solution, coating the lithium salt solution on a first pole piece of a negative electrode, and forming an intermediate layer on the surface of the first pole piece after the lithium salt solution on the first pole piece is solidified;
and S3A, repeating the steps S2 and S3 to obtain the negative composite electrode plate.
Preferably, (1) preparation of the first pole piece of the positive electrode:
S1A1, weighing 70-90wt% of positive electrode active material, 5-15wt% of first conductive agent and 5-10wt% of second binder, adding into a second solvent, mixing and stirring to obtain slurry A with the solid content of 40-60 wt%;
S2A2, coating the slurry A on a current collector, and drying to obtain a positive electrode plate;
(2) Preparing a first pole piece of a negative electrode:
S1B1, weighing 70-90wt% of anode active material, 5-15wt% of second conductive agent and 5-10wt% of third binder, adding into a third solvent, mixing and stirring to obtain slurry B with the solid content of 40-60 wt%;
S2B2, coating the slurry B on a current collector, and drying to obtain the negative electrode plate.
Preferably, the positive electrode active material is any one or a combination of more than two of NCM811, NCM 523, NCM 622, liFePO 4; the negative electrode active material is graphite, si/C450 or SiO X Any one or a combination of two or more of/C.
Preferably, the first conductive agent is any one or more of VGCF, super P and KS 6; the second binder may be one or more of PVDF-CTFE, PVDF-HFP, CMC, LA132, PVDF5130, and PVDF900, and the second solvent is at least one of NMP, H2O, DMC, ethanol, butyl butyrate, and isobutyl isobutyrate.
Preferably, the second conductive agent is VGCF; the third binder may be at least one of PVDF-CTFE, NBR, SBR, LA132, CMC, PVDF-HFP, PVDF5130 and PVDF900, and the third solvent is at least one of NMP, H2O, DMC, ethanol, butyl butyrate and isobutyl isobutyrate.
Preferably, the electrolyte is a sulfide electrolyte.
Preferably, the sulfide electrolyte is Li 6 PS 5 Cl、Li 3 PS4 and Li 2 S-P 2 S 5 Any one or a combination of two or more of them; the lithium salt is LiTFSI, liFSI, liODFB, liPF 2 And LiPF 6 At least one of (a) and (b); the first adhesive is any one or the combination of more than two of methyl vinyl silicone rubber, NBR, PVDF, PVDF-HFP and PVDF-CTFE; the first solvent is at least one of n-heptane, methyl vinyl ketone, n-hexane, isobutyl isobutyrate, butyl butyrate xylene, and toluene.
Preferably, the temperature of the heating treatment is 50-70 ℃, and the time of the heating treatment is 5-30min.
At this temperature, the intermediate layer will dissolve, but the electrolyte membrane on the intermediate layer will not; the heating time is matched with the heating temperature, so that the intermediate layer can be ensured to be fully infiltrated into the first pole piece, and meanwhile, side reactions caused by long-time contact between the intermediate layer and the sulfide electrolyte membrane layer are avoided.
Preferably, the solid content of the mixture is 56-65%, the mass ratio of sulfide electrolyte after the first solvent is removed from the mixture is 95-99%, and the mass ratio of the first binder is 1-5%.
The invention also provides a solid-state battery, which is prepared by the preparation method of the solid-state battery or comprises the composite electrode slice.
The invention has the beneficial effects that:
in the prior art, when a solid-state battery pole piece is prepared by slurry, sulfide electrolyte and polar substances are extremely easy to react to cause loss of ionic conductivity, so that a nonpolar or low-polarity binder and a solvent are required to be selected, but the low-polarity binder is very weak in viscosity, and the pole piece is poor in adhesiveness; moreover, when the solid-state battery pole piece is prepared, the sulfide electrolyte is sensitive to air and water, and needs to be operated in an environment with almost no water and oxygen, so that the efficiency is extremely low, and the manufacturing cost is extremely high; when the method provided by the invention is used for preparing the solid-state battery, the first pole piece can directly adopt the positive pole piece or the negative pole piece of the existing liquid-state battery, so that the problem that sulfide electrolyte, binder and solvent in the slurry of the solid-state battery are difficult to balance is fundamentally avoided, and meanwhile, the problems of low efficiency, high cost and the like caused by severe environmental requirements during the preparation of the solid-state battery pole piece are solved, thereby being beneficial to pushing the solid-state battery to realize industrialization;
according to the invention, the mixture is directly coated on the intermediate layer instead of the first pole piece, so that the first solvent is prevented from directly contacting with the first pole piece through the intermediate layer, the swelling of the adhesive caused by the first solvent in the pole piece layer is thoroughly avoided, and the phenomena of reduced internal adhesion force and poor pole piece performance of the first pole piece are avoided; after the heating treatment, the lithium-conducting solvent is changed into a state with good fluidity, the intermediate layer is infiltrated into the first pole piece through the pores, and a large number of ion passages are constructed in the pole piece layer by the lithium salt solution, so that the first pole piece still has enough ion conducting performance when applied to the solid-state battery;
the middle layer is finally immersed into the gap in the first pole piece, so that the adhesive force of the lithium salt solution can enhance the mechanical strength inside the pole piece, and the whole pole piece is less prone to cracking in the battery cycle process; in addition, as the intermediate layer is deeply pricked into the first pole piece after being dissolved, the connection between the electrolyte membrane and the first pole piece is very stable, and the integral structural strength of the battery is enhanced;
the scheme is that the intermediate layer is arranged without adding any inactive component in the battery, so that no sacrifice is caused to the energy of the battery, and the ultra-thin electrolyte layer is applied due to the temporary intermediate layer, so that the energy density of the battery can be improved; in addition, due to the special property of the lithium-conducting solvent, the lithium-conducting solvent can absorb certain heat to change the state of the lithium-conducting solvent, has certain heat storage and temperature control effects, so that the high-temperature safety of the battery is further improved, and when the lithium-conducting solvent in the first pole piece is changed into the lithium-conducting solvent with good fluidity, the ion transmission speed in the whole first pole piece is increased, and the power density of the battery is enhanced.
Drawings
Fig. 1 is a flow chart of the preparation process of the composite electrode sheet of example 1.
Detailed Description
The principles and features of the present invention are described below with reference to fig. 1, but the examples are provided for illustration only and are not intended to limit the scope of the invention.
Example 1
The embodiment relates to a preparation method of a composite electrode slice, which comprises the following preparation steps:
s1, heating to enable a lithium guide solvent to be in a liquid state, weighing the lithium guide solvent and lithium salt, mixing to obtain a lithium salt solution, coating the lithium salt solution on a first pole piece, gradually cooling the temperature of the lithium salt solution on the first pole piece to room temperature, and forming an intermediate layer on the surface of the first pole piece after the lithium salt solution is gradually solidified;
s2, adding the electrolyte and the first binder into a first solvent, mixing and stirring to obtain a mixture, coating the mixture on the middle layer, and solidifying the mixture on the middle layer after the first solvent volatilizes to form a layer of electrolyte membrane on the middle layer to obtain a middle pole piece;
and S3, carrying out heating treatment on the middle electrode plate, and obtaining the composite electrode plate after the middle layer is partially or completely soaked into the first electrode plate.
Preferably, the lithium-conducting solvent is at least one of succinonitrile and bis-trifluoroacetamide. The concentration of the lithium salt in the lithium salt solution is 0.5mol/L to 2mol/L.
Preferably, (1) preparation of a positive electrode composite electrode sheet:
S1A, preparing a first pole piece of the positive electrode;
S2A, weighing a lithium guide solvent and lithium salt, mixing to obtain a lithium salt solution, coating the lithium salt solution on a first pole piece of an anode, and forming an intermediate layer on the surface of the first pole piece after the lithium salt solution on the first pole piece is solidified;
S3A, repeating the steps S2 and S3 to obtain a positive composite electrode plate;
(2) Preparation of a negative electrode composite electrode plate:
S1A, preparing a first pole piece of a negative electrode;
S2A, weighing a lithium-conducting solvent and lithium salt, mixing to obtain a lithium salt solution, coating the lithium salt solution on a first pole piece of a negative electrode, and forming an intermediate layer on the surface of the first pole piece after the lithium salt solution on the first pole piece is solidified;
and S3A, repeating the steps S2 and S3 to obtain the negative composite electrode plate.
Specifically, (1) preparation of a positive electrode composite electrode plate:
S1A, preparing a first pole piece of the positive electrode;
S1A1, weighing 1.6g of positive electrode active material NCM811, 0.2g of first conductive agent VGCF and 0.2g of second binder PVDF-CTFE, adding into 1.846g of isobutyl isobutyrate serving as a second solvent, and then mixing slurry at a rotating speed of 1000rpm in a vibration ball mill for 60min to obtain slurry A with a solid content of 52 wt%;
S2A2, coating the slurry A on an aluminum foil by using a 500um SQZ four-side preparation device, and drying at 100 ℃ for 12 hours to obtain a first pole piece of the positive electrode;
S2A, weighing 9.85g succinonitrile (density 0.985 g/ml) and 2.87g LiTFSI (molecular weight 287.0), mixing, and heating and stirring at 60deg.C for 20min to completely dissolve and disperse uniformly to obtain lithium salt solution. Then coating the lithium salt solution on a first pole piece of the positive electrode by using a 100um SQZ four-side preparation device, and forming an intermediate layer on the first pole piece of the positive electrode after the lithium salt solution is cooled and solidified;
s2, adding 4gLi PS5Cl and 0.21g PVDF-CTFE into 2.26g isobutyl isobutyrate, mixing and stirring to obtain a mixture, then mixing the mixture in a high-speed centrifuge at a rotating speed of 1000rpm for 20min, coating the mixture on the middle layer by using a SQZ four-side preparation device of 500um, and obtaining a middle pole piece after the mixture on the middle layer is solidified;
and S3, treating the middle electrode plate for 30min at the temperature of 60 ℃ to completely dissolve and infiltrate the lithium salt solution into the gaps of the electrode plate, and naturally cooling to obtain the positive composite electrode plate.
(2) Preparation of a negative electrode composite electrode plate:
S1A, preparing a first pole piece of a negative electrode;
S1A1, weighing 1.6g of a negative electrode active material Si/C-450, 0.2g of a second conductive agent VGCF and 0.2g of a third binder PVDF-CTFE, adding the second conductive agent VGCF and the third binder PVDF-CTFE into 1.846g of isobutyl isobutyrate serving as a third solvent, and then mixing the slurry in a vibration ball mill at a rotating speed of 1000rpm for 60min to obtain a slurry B with a solid content of 46 wt%;
S2A2, coating slurry B on a stainless steel foil by using a 400um SQZ four-side preparation device, drying at 100 ℃ for 12 hours, and obtaining a first pole piece of the negative electrode after drying;
S2A, weighing 9.85g succinonitrile (density 0.985 g/ml) and 2.87g LiTFSI (molecular weight 287.0), mixing, and heating and stirring at 60deg.C for 20min to completely dissolve and disperse uniformly to obtain lithium salt solution. Then respectively coating the lithium salt solution on a first pole piece of the negative electrode by using a 100um SQZ four-side preparation device, and forming an intermediate layer on the first pole piece of the negative electrode after the lithium salt solution is cooled and solidified;
s2, adding 4gLi PS5Cl and 0.21g PVDF-CTFE into 2.26g isobutyl isobutyrate, mixing and stirring to obtain a mixture, then mixing the mixture in a high-speed centrifuge at a rotating speed of 1000rpm for 20min, coating the mixture on the middle layer by using a SQZ four-side preparation device of 500um, and obtaining a middle pole piece after the mixture on the middle layer is solidified;
and S3, treating the middle electrode plate for 30min at the temperature of 60 ℃ to completely dissolve and infiltrate the lithium salt solution into the gaps of the electrode plate, and obtaining the negative electrode composite electrode plate after the lithium salt solution is naturally cooled.
Example 2
This embodiment differs from embodiment 1 in that:
S2A, 9.85g of a mixture of succinonitrile and bis (trifluoroacetamide) (mass ratio 1:1), 2.87. 2.87gLiTFSI, liFSI, liODFB, liPF are weighed out 2 And LiPF 6 Mixing to obtain a lithium salt solution (mass ratio of 1:1:1:1), heating and stirring the lithium salt solution at 70 ℃ for 20min to completely dissolve and uniformly disperse the lithium salt solution, coating the lithium salt solution on a first pole piece of a negative electrode by using a 100um SQZ four-side preparation device, and forming an intermediate layer on the surface of the first pole piece after the lithium salt solution on the first pole piece is solidified;
and S3, treating the middle electrode plate for 30min at the temperature of 70 ℃ to completely dissolve and infiltrate the lithium salt solution into the gaps of the electrode plate, and obtaining the negative electrode composite electrode plate after the lithium salt solution is naturally cooled.
The remainder was the same as in example 1.
Example 3
This embodiment differs from embodiment 1 in that:
and (3) treating the middle electrode plate at 60 ℃ for 10min to completely dissolve and infiltrate the lithium salt solution into the gaps of the electrode plate, and naturally cooling to obtain the negative electrode composite electrode plate. The remainder was the same as in example 1.
Comparative example 1
The comparative example relates to the preparation of a positive electrode composite electrode sheet and the preparation of a negative electrode sheet, and specifically comprises the following steps:
(1) Preparation of a positive electrode composite electrode plate:
S1C, preparing a positive pole piece;
S1C1, weighing 1.6g of positive electrode active material NCM811, 0.2g of conductive agent VGCF and 0.2g of binder PVDF-CTFE, adding into 1.846g of isobutyl isobutyrate serving as a first solvent, and then mixing the slurry in a vibration ball mill at a rotating speed of 1000rpm for 60min to obtain slurry C;
S2C2, coating the slurry C on an aluminum foil by using a SQZ four-side preparation device with 500um, and drying at 100 ℃ for 12 hours to obtain a first pole piece;
s2, adding 4gLi PS5Cl and 0.21g PVDF-CTFE into 2.26g isobutyl isobutyrate, mixing and stirring to obtain a mixture, then mixing the mixture in a high-speed centrifuge at a rotating speed of 1000rpm for 20min, and then coating the mixture on the first pole piece by using a 500um SQZ four-side preparation device to obtain an intermediate pole piece;
s3, treating the middle pole piece for 30min at the temperature of 60 ℃ to enable the lithium salt solution to be completely dissolved and infiltrated into the gaps of the pole piece, and obtaining the positive pole piece after the lithium salt solution is naturally cooled.
(2) Preparing a negative electrode plate:
S1C, preparing a negative electrode plate;
S1C1, weighing 1.6g of negative electrode active material Si/C-450, 0.2g of conductive agent VGCF and 0.2g of binder PVDF-CTFE, adding into 1.846g of isobutyl isobutyrate serving as a first solvent, and then mixing slurry at a rotating speed of 1000rpm in a vibration ball mill for 60min to obtain slurry C;
S2C2, coating the slurry C on an aluminum foil by using a SQZ four-side preparation device with 500um, and drying at 100 ℃ for 12 hours to obtain a first pole piece;
s2, adding 4gLi PS5Cl and 0.21g PVDF-CTFE into 2.26g isobutyl isobutyrate, mixing and stirring to obtain a mixture, then mixing the mixture in a high-speed centrifuge at a rotating speed of 1000rpm for 20min, and then coating the mixture on the first pole piece by using a 500um SQZ four-side preparation device to obtain an intermediate pole piece;
s3, treating the middle pole piece for 30min at the temperature of 60 ℃ to enable the lithium salt solution to be completely dissolved and infiltrated into the gaps of the pole piece, and obtaining the negative pole piece after the lithium salt solution is naturally cooled.
Evaluation of Electrical Properties
The solid-state high-voltage die is selected for battery assembly, the positive electrode composite electrode plate and the negative electrode composite electrode plate prepared in the examples 1 to 3 and the positive electrode plate and the negative electrode plate prepared in the comparative example 1 are pressed for 2min under 600Mpa, then the indium sheet with the thickness of 10mm and the lithium sheet with the thickness of 8mm are sequentially placed, and the battery is assembled by pressing and molding for 2min under 600Mpa again. And finally, carrying out charge and discharge test of 0.05C on the assembled battery at 45 ℃, wherein the voltage of the positive electrode is 2.1-3.4V, and the voltage of the negative electrode is-0.6-0.9V. The results are shown in Table 1 below, which are comparative data of the first charge and discharge capacities of examples 1 to 3 and comparative example 1.
Table 1 results of comparison of the specific capacities of examples 1-3 and comparative example 1
As can be seen from table 1, after the intermediate layer was used, the performance of both the positive electrode and the negative electrode was significantly improved.
As can be seen from the above, the lithium salt solution is coated on the first pole piece, and the first solvent in the electrolyte slurry is isolated through the intermediate layer, so that the phenomena of reduced adhesive force and poor pole piece performance caused by swelling of the first adhesive in the first pole piece due to the first solvent are avoided; in addition, the lithium salt solution is completely dissolved and immersed in the first pole piece to serve as an ion passage in the first pole piece, so that the performance of the active material is ensured.
In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.
The foregoing is only illustrative of the present invention and is not to be construed as limiting thereof, but rather as various modifications, equivalent arrangements, improvements, etc., within the spirit and principles of the present invention.
Claims (10)
1. The preparation method of the composite electrode slice is characterized by comprising the following preparation steps:
s1, weighing a lithium guide solvent and lithium salt, mixing to obtain a lithium salt solution, coating the lithium salt solution on a first pole piece, and forming an intermediate layer on the surface of the first pole piece after the lithium salt solution on the first pole piece is solidified;
s2, adding electrolyte and a first binder into a first solvent, mixing and stirring to obtain a mixture, coating the mixture on the intermediate layer, and obtaining an intermediate pole piece after the mixture on the intermediate layer is solidified;
and S3, carrying out heating treatment on the middle electrode plate, and obtaining the composite electrode plate after the middle layer is partially or completely soaked into the first electrode plate.
2. The method for producing a composite electrode sheet according to claim 1, wherein the lithium-conducting solvent is at least one of succinonitrile and bistrifluoroacetamide, and the concentration of the lithium salt in the lithium salt solution is 0.5mol/L to 2mol/L.
3. The method for manufacturing a composite electrode sheet according to claim 1, wherein the first electrode sheet is a positive electrode sheet or a negative electrode sheet.
4. The method for producing a composite electrode sheet according to claim 1, wherein the electrolyte is Li 6 PS 5 Cl、Li 3 PS4 and Li 2 S-P 2 S 5 Any one or a combination of two or more of them; the lithium salt is LiTFSI, liFSI, liODFB, liPF 2 And LiPF 6 At least one of them.
5. The method for preparing a composite electrode sheet according to claim 1, wherein in step S1, before the lithium salt solution is coated on the first electrode sheet, a lithium-conducting solvent is heated to make the lithium-conducting solvent be in a liquid state;
in the step S3, the temperature of the heating treatment is 50-70 ℃, and the time of the heating treatment is 5-30min.
6. The method of manufacturing a composite electrode sheet according to claim 1, wherein the first binder is at least one of methyl vinyl silicone rubber, NBR, PVDF, PVDF-HFP, and PVDF-CTFE; the first solvent is at least one of n-heptane, methyl vinyl ketone, n-hexane, isobutyl isobutyrate, butyl butyrate xylene and toluene.
7. A composite electrode sheet, characterized in that it is produced by the method for producing a composite electrode sheet according to any one of claims 1 to 6.
8. A method of manufacturing a solid-state battery, comprising the steps of:
a1, weighing a lithium guide solvent and lithium salt, mixing to obtain lithium salt solution, respectively coating the lithium salt solution on an anode electrode plate and a cathode electrode plate, and respectively forming an anode intermediate layer and a cathode intermediate layer on the surfaces of the anode electrode plate and the cathode electrode plate after the lithium salt solution is solidified;
a2, adding the electrolyte and the first binder into the first solvent, mixing and stirring to obtain a mixture, respectively coating the mixture on the positive electrode intermediate layer and the negative electrode intermediate layer, solidifying the mixture on the positive electrode intermediate layer to obtain a positive electrode intermediate pole piece, and solidifying the mixture on the negative electrode intermediate layer to obtain a negative electrode intermediate pole piece;
a3, assembling the positive electrode middle pole piece and the negative electrode middle pole piece into a full battery;
a4, carrying out heating treatment on the full battery, wherein the positive electrode intermediate layer is partially or completely infiltrated into the positive electrode plate to obtain a positive electrode composite plate, and the negative electrode intermediate layer is partially or completely infiltrated into the negative electrode plate to obtain a negative electrode composite plate;
and A5, applying pressure to the heated full battery to tightly combine the positive electrode composite pole piece and the negative electrode composite pole piece.
9. The method for manufacturing a solid-state battery according to claim 8, wherein at least one of the following conditions is satisfied:
a. the lithium-conducting solvent is at least one of succinonitrile and bis (trifluoroacetamide);
b. the concentration of the lithium salt in the lithium salt solution is 0.5mol/L-2mol/L;
c. the electrolyte is Li 6 PS 5 Cl、Li 3 PS4 and Li 2 S-P 2 S 5 Any one or a combination of two or more of them;
d. the lithium salt is LiTFSI, liFSI, liODFB, liPF 2 And LiPF 6 At least one of (a) and (b);
e. in the step A1, before the lithium salt solution is coated on the positive electrode plate or the negative electrode plate, a lithium guiding solvent is heated, so that the lithium guiding solvent is in a liquid state;
f. in the step A4, the temperature of the heating treatment is 50-70 ℃, and the time of the heating treatment is 5-30min;
g. the first adhesive is at least one of methyl vinyl silicone rubber, NBR, PVDF, PVDF-HFP and PVDF-CTFE;
h. the first solvent is at least one of n-heptane, methyl vinyl ketone, n-hexane, isobutyl isobutyrate, butyl butyrate xylene and toluene.
10. A solid-state battery comprising the composite electrode sheet according to claim 7, or the solid-state battery according to any one of claims 8 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311063796.0A CN116779768B (en) | 2023-08-23 | 2023-08-23 | Composite electrode plate and preparation method thereof, solid-state battery and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311063796.0A CN116779768B (en) | 2023-08-23 | 2023-08-23 | Composite electrode plate and preparation method thereof, solid-state battery and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN116779768A true CN116779768A (en) | 2023-09-19 |
| CN116779768B CN116779768B (en) | 2023-11-21 |
Family
ID=87994850
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311063796.0A Active CN116779768B (en) | 2023-08-23 | 2023-08-23 | Composite electrode plate and preparation method thereof, solid-state battery and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116779768B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109659500A (en) * | 2018-12-18 | 2019-04-19 | 西北工业大学 | Reduce solid electrolyte/cathode of lithium interface impedance lithium piece, preparation method and application |
| CN115692714A (en) * | 2022-11-17 | 2023-02-03 | 电子科技大学长三角研究院(湖州) | Protective layer of negative electrode interface of sulfide solid-state lithium-sulfur battery, preparation method and battery |
-
2023
- 2023-08-23 CN CN202311063796.0A patent/CN116779768B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109659500A (en) * | 2018-12-18 | 2019-04-19 | 西北工业大学 | Reduce solid electrolyte/cathode of lithium interface impedance lithium piece, preparation method and application |
| CN115692714A (en) * | 2022-11-17 | 2023-02-03 | 电子科技大学长三角研究院(湖州) | Protective layer of negative electrode interface of sulfide solid-state lithium-sulfur battery, preparation method and battery |
Also Published As
| Publication number | Publication date |
|---|---|
| CN116779768B (en) | 2023-11-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110581314B (en) | Multilayer-structure composite solid electrolyte membrane, preparation method thereof and solid battery | |
| CN108963327B (en) | Inorganic filler composite PEO solid electrolyte material, preparation method and all-solid-state battery | |
| CN110581311B (en) | Composite solid electrolyte membrane, preparation method thereof and solid battery | |
| CN113130895B (en) | Solid-state lithium ion battery and preparation method thereof | |
| CN110093054B (en) | Cross-linked copolymer, polymer electrolyte, preparation methods of cross-linked copolymer and polymer electrolyte, and all-solid-state lithium ion battery | |
| CN113764625B (en) | Sulfide silicon-based negative plate, preparation method thereof and all-solid-state lithium ion battery | |
| CN110676433B (en) | Composite lithium cathode, preparation method thereof and lithium battery | |
| CN112652815B (en) | Low-internal-resistance all-solid-state battery and preparation method thereof | |
| CN113851609B (en) | Silicon-based negative electrode plate, preparation method thereof and all-solid-state lithium ion battery | |
| CN103208651A (en) | Siloxane-based solid electrolyte and preparation and application thereof | |
| CN110931852A (en) | Composite solid electrolyte, method for preparing same, and lithium secondary solid battery comprising same | |
| CN111373590A (en) | Method for manufacturing all-solid-state battery | |
| CN116072805A (en) | Preparation method of battery pole piece and all-solid-state battery | |
| CN114824226B (en) | Negative electrode plate, preparation method thereof, lithium ion battery and electric equipment | |
| CN113381065A (en) | Polymer composite solid electrolyte and preparation method and application thereof | |
| CN115579526A (en) | Solid-state battery and preparation method and application thereof | |
| CN112864454A (en) | Multilayer solid electrolyte, preparation method thereof and solid lithium battery | |
| CN113903983A (en) | Organic-inorganic composite solid electrolyte membrane, preparation method thereof and all-solid-state lithium battery using same | |
| CN110676515B (en) | Preparation method of low-temperature high-energy-density lithium ion battery | |
| CN116779768B (en) | Composite electrode plate and preparation method thereof, solid-state battery and preparation method thereof | |
| CN115714200B (en) | Method for preparing solid-state battery by selective solidification | |
| CN116053576A (en) | All-solid-state battery with no interface, low impedance and high safety and preparation method thereof | |
| CN115498249A (en) | Double-layer composite solid electrolyte membrane, preparation method thereof and all-solid-state battery | |
| CN113363573B (en) | Preparation method of solid electrolyte, solid electrolyte and all-solid-state battery | |
| CN115425287A (en) | All-solid-state battery containing alloy type negative electrode and elastic electrolyte |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |