Summary of the invention
The technical problem that the present invention mainly solves is distributed in lithium ion cell electrode by high conductivity material graphene uniform, improves that the electronic conductivity of electrode is high, the overall chemical property of lithium ion diffusion coefficient and electrode.
For solving the problems of the technologies described above, the technical scheme that the present invention adopts is: Graphene is passed through ultrasonic disperse in advance, progressively join in electrode slurry in the mode of spraying again, more effectively easy for Graphene is dispersed in battery material, utilize graphene conductive characteristic and its conductivity is not fully exerted, the performance of electrode material is made to obtain more abundant more effective performance with this, the overall homogeneity of the lithium ion cell electrode improved and batch consistency, improve the properties of lithium ion battery greatly.Lithium ion cell electrode electronic conductivity provided by the invention is high, lithium ion diffusion coefficient large, and its side's of preparation technique is simple, is easy to realize industrialization and continuous prodution.
A kind of lithium ion cell electrode is provided, it is characterized in that: described lithium ion cell electrode comprises the electrode material coating of matrix and graphene-containing.
The preparation method of described lithium ion cell electrode, the steps include:
(1) by Graphene, additive be 1:(20 ~ 1000 in mass ratio) weighing, then ultrasonic disperse at a certain temperature, as conductive agent part in (2);
(2) by battery material, conductive agent, additive in mass ratio for (80 ~ 95): (2 ~ 10): (3 ~ 10) weighing also adds the dispersant preparation slurry of gross mass (0.5 ~ 10) times quality, and in slurry preparation process, Graphene mixed liquor scattered to (1) is sprayed onto in cell size, then the cell size mixed to be coated on matrix to dry at a certain temperature and to obtain electrode material coating and make described lithium ion cell electrode.
In a preferred embodiment of the present invention, described additive can be one or more in the polymer on oxalic acid, polyvinylidene fluoride, polytetrafluoroethylene, polyoxyethylene, polymethyl acrylate, polyvinylpyrrolidone, butadiene-styrene rubber, sodium carboxymethylcellulose or acrylate basis.
In a preferred embodiment of the present invention, described conductive agent comprises graphite-like (as: KS-6, SO etc., comprise graphite that is natural, Prof. Du Yucang or modification), one or more in carbon fiber, Graphene, hard carbon, carbon nano-tube, conductive black (as: acetylene black, Ketjen black etc.).
In a preferred embodiment of the present invention, described battery material is spinel lithium manganate, phosphoric acid vanadium lithium, lithium manganese phosphate, lithium-rich manganese base material, one or more in cobalt acid lithium, nickel cobalt manganese lithium material, nickel cobalt aluminium lithium material, LiFePO4 or they material modified, and its corresponding matrix is the aluminium such as aluminium foil, aluminium flake matter matrix; Also can be one or more in graphite (natural, Prof. Du Yucang or modification), carbonaceous mesophase spherules, hard carbon, soft carbon, Graphene, nitride, silica-base material, lithium titanate, and its corresponding matrix be the copper matrix such as Copper Foil, copper sheet.
In a preferred embodiment of the present invention, described dispersant comprise in water, methyl alcohol, ethanol, acetone, isopropyl alcohol, 1-METHYLPYRROLIDONE one or more.
In a preferred embodiment of the present invention, described drying condition is toast 20min ~ 8h at not higher than the temperature of 160 DEG C.
In a preferred embodiment of the present invention, described step (1) ultrasonic disperse temperature is not higher than 95 DEG C, and jitter time is at 10min ~ 10h.
In a preferred embodiment of the present invention, described step (2) coating method is spraying, blade coating or roller coat, and electrode material coating layer thickness is less than 500 μm.
The invention has the beneficial effects as follows: the lithium ion cell electrode electronic conductivity prepared by the present invention is high, lithium ion diffusion coefficient is large, improve the overall homogeneity of lithium ion cell electrode and batch consistency, improve the properties of lithium ion battery greatly, and its side's of preparation technique is simple, is easy to realize industrialization and continuous prodution.
Embodiment
Below in conjunction with accompanying drawing, preferred embodiment of the present invention is described in detail, can be easier to make advantages and features of the invention be readily appreciated by one skilled in the art, thus more explicit defining is made to protection scope of the present invention.
Embodiment one:
(1) be 1:30 weighing by Graphene, NMP according to weight ratio, for subsequent use after 30 DEG C of ultrasonic disperse 6h;
(2) be 80:10:10 weighing by spinel lithium manganate, conductive agent, pvdf according to mass ratio, wherein Graphene in conductive agent, acetylene black, KS-6 ratio are 1:5:4 [note: Graphene is for subsequent use to be ready in (1)], the NMP adding gross mass 1.5 times prepares slurry, in slurry preparation process, the Graphene mixed liquor prepared by (1) is sprayed onto in electrode slurry, more mixed uniformly cell size blade coating is dried 4h and obtains 50 μm of thick electrode material coatings (in Fig. 1 2) to upper 120 DEG C of aluminium foil (in Fig. 1 1) and make lithium ion cell electrode.
Comparative example one:
Be 80:10:10 weighing by spinel lithium manganate, conductive agent, pvdf according to mass ratio, wherein in conductive agent, acetylene black, KS-6 ratio are 5:5, after the NMP adding gross mass 1.5 times is made into slurry, blade coating is on aluminium foil, then 120 DEG C are dried 4h and obtain electrode coating and make lithium ion cell electrode.
Embodiment two:
(1) be 1:100 weighing by Graphene, NMP according to weight ratio, for subsequent use after 40 DEG C of ultrasonic disperse 3h;
(2) be 80:10:10 weighing by LiFePO4, conductive agent, pvdf according to mass ratio, wherein Graphene in conductive agent, acetylene black, SO ratio are 1:5:4 [note: Graphene is for subsequent use to be ready in (1)], the NMP adding gross mass 1 times prepares slurry, in slurry preparation process, the Graphene mixed liquor prepared by (1) is sprayed onto in electrode slurry, more mixed uniformly cell size is rolled onto upper 110 DEG C of aluminium foil (in Fig. 1 1) and dries 7h and obtain 100 μm of thick electrode material coatings (in Fig. 1 2) and make lithium ion cell electrode.
Comparative example two:
Be 80:10:10 weighing by brilliant for point LiFePO4, conductive agent, pvdf according to mass ratio, wherein in conductive agent, acetylene black, SO ratio are 5:5, after the NMP adding gross mass 1 times is made into slurry, roller coat is on aluminium foil, then 110 DEG C are dried 7h and obtain electrode coating and make lithium ion cell electrode.
Embodiment three:
(1) be 1:500 weighing by Graphene, NMP according to weight ratio, for subsequent use after 30 DEG C of ultrasonic disperse 5h;
(2) be 80:10:10 weighing by nickle cobalt lithium manganate, conductive agent, pvdf according to mass ratio, wherein Graphene in conductive agent, acetylene black, KS-6 ratio are 2:5:3 [note: Graphene is for subsequent use to be ready in (1)], the NMP adding gross mass 1.3 times prepares slurry, in slurry preparation process, the Graphene mixed liquor prepared by (1) is sprayed onto in electrode slurry, more mixed uniformly cell size is sprayed to upper 120 DEG C of aluminium foil (in Fig. 1 1) and dry 5h and obtain 90 μm of thick electrode material coatings (in Fig. 1 2) and make lithium ion cell electrode.
Comparative example three:
Be 80:10:10 weighing by nickle cobalt lithium manganate, conductive agent, pvdf according to mass ratio, wherein in conductive agent, acetylene black, KS-6 ratio are 5:5, be coated in above aluminium foil after the NMP adding gross mass 1.4 times is made into slurry, then 120 DEG C are dried 5h and obtain electrode coating and make lithium ion cell electrode.
Embodiment four:
(1) be 1:40 weighing by Graphene, ethanol according to weight ratio, for subsequent use after 50 DEG C of ultrasonic disperse 4h;
(2) be 85:8:7 weighing by carbonaceous mesophase spherules, conductive agent, pvdf according to mass ratio, wherein Graphene in conductive agent, acetylene black ratio are 5:5 [note: Graphene is for subsequent use to be ready in (1)], the NMP adding gross mass 1.1 times prepares slurry, in slurry preparation process, the Graphene mixed liquor prepared by (1) is sprayed onto in electrode slurry, more mixed uniformly cell size blade coating is dried 4h and obtains 120 μm of thick electrode material coatings (in Fig. 1 2) to upper 110 DEG C of Copper Foil (in Fig. 1 1) and make lithium ion cell electrode.
Comparative example four:
Be 85:8:7 weighing by carbonaceous mesophase spherules, acetylene black, pvdf according to mass ratio, after the NMP adding gross mass 1.1 times is made into slurry, blade coating is on Copper Foil, then 110 DEG C are dried 4h and obtain electrode coating and make lithium ion cell electrode.
Embodiment five:
(1) be 1:40 weighing by Graphene, ethanol according to weight ratio, for subsequent use after 50 DEG C of ultrasonic disperse 4h;
(2) be 88:6:6 weighing by Delanium, conductive agent, pvdf according to mass ratio, wherein Graphene in conductive agent, acetylene black ratio are 5:5 [note: Graphene is for subsequent use to be ready in (1)], the NMP adding gross mass 1.2 times prepares slurry, in slurry preparation process, the Graphene mixed liquor prepared by (1) is sprayed onto in electrode slurry, more mixed uniformly cell size blade coating is dried 6h and obtains 150 μm of thick electrode material coatings (in Fig. 1 2) to upper 100 DEG C of Copper Foil (in Fig. 1 1) and make lithium ion cell electrode.
Comparative example five:
Be 88:6:6 weighing by Delanium, acetylene black, pvdf according to mass ratio, after the NMP adding gross mass 1.2 times is made into slurry, blade coating is on Copper Foil, then 100 DEG C are dried 6h and obtain electrode coating and make lithium ion cell electrode.
Battery performance test improves data display:
Table one: the discharge capacity of embodiment one and the battery performance test of comparative example one and first coulombic efficiency
| Specific discharge capacity, mAh/g | Coulombic efficiency, % |
| Embodiment one | 107.2 | 92.4 |
| Comparative example one | 106.1 | 87.2 |
Table two: the discharge capacity of the battery performance test of embodiment two and comparative example two and discharge platform voltage
| Discharge platform voltage V | Specific discharge capacity, mAh/g |
| Embodiment two | 3.40 | 155.3 |
| Comparative example two | 3.39 | 150.5 |
Table three: the discharge capacity of embodiment three and the battery performance test of comparative example three and first coulombic efficiency
| Specific discharge capacity, mAh/g | Coulombic efficiency, % |
| Embodiment three | 155.1 | 89 |
| Comparative example three | 153.5 | 85.2 |
Table four: the discharge capacity of embodiment four and the battery performance test of comparative example four and first coulombic efficiency
| Specific discharge capacity, mAh/g | Coulombic efficiency, % |
| Embodiment four | 360.2 | 92 |
| Comparative example four | 343.8 | 91.5 |
Table five: the discharge capacity of embodiment five and the battery performance test of comparative example five and first coulombic efficiency
| Specific discharge capacity, mAh/g | Coulombic efficiency, % |
| Embodiment five | 358.4 | 93.2 |
| Comparative example five | 345.7 | 92 |
The beneficial effect of lithium ion cell electrode of the present invention is: the lithium ion cell electrode electronic conductivity prepared by the present invention is high, lithium ion diffusion coefficient is large, improve the overall homogeneity of lithium ion cell electrode and batch consistency, improve the properties of lithium ion battery greatly, and its side's of preparation technique is simple, is easy to realize industrialization and continuous prodution.
The preparation method of lithium ion cell electrode of the present invention extends lithium ion cell electrode preparation technology, improve electrode interior structure, improve battery heat dispersion, improve electronics and ion transmission performance etc., can large-scale production be realized, have certain impetus to the development of lithium ion battery and application thereof.
The foregoing is only embodiments of the invention; not thereby the scope of the claims of the present invention is limited; every utilize specification of the present invention and accompanying drawing content to do equivalent structure or equivalent flow process conversion; or be directly or indirectly used in other relevant technical fields, be all in like manner included in scope of patent protection of the present invention.