42results about How to "Reduce interface side reactions" patented technology

The invention discloses a positive pole piece which comprises a positive pole current collector and a positive pole diaphragm arranged on at least one surface of the positive pole current collector, and the positive pole diaphragm comprises a positive pole active substance; the positive electrode active substance comprises at least two lithium nickel cobalt manganese oxides LiNixCoyMn1-x-yO2 withdifferent morphologies and average particle sizes D50, wherein one type is primary particle single crystal LiNixCoyMn1-x-yO2, and the other type is secondary particle polycrystalline LiNixCoyMn1-x-yO2; the weight ratio [omega] of the single crystal to the polycrystalline LiNixCoyMn1-x-yO2 satisfies the relational expression: 0.1<=[omega]<=9. By adjusting the ratio of the primary particle single crystal to the secondary particle polycrystalline material and the nickel content, the positive pole piece can have better thermal stability and excellent dynamic performance, so that the lithium ion secondary battery based on the positive pole piece has the characteristics of long cycle life at normal temperature and high temperature.

The invention discloses a preparation method of a coated ternary nickel-cobalt-manganese lithium oxide positive electrode material. The preparation method comprises the following steps of (1) preparing a ternary nickel-cobalt-manganese lithium precursor; (2) preparing an oxide-coated ternary nickel-cobalt-manganese lithium precursor; and (3) preparing an ion conductor oxide-coated ternary nickel-cobalt-manganese lithium positive electrode material. By the preparation method of the positive electrode material, a lithium ion is easy to de-intercalate from a surface layer of the material, and thehigh-temperature circulation performance of the material is improved; a coating layer does not react with an electrolyte, interface side reaction caused by contact of the main body material and the electrolyte is reduced, and the safety of the material is improved; the processing performance of a pole plate during the uniform coating process is improved, and the high-temperature circulation performance of the material after being assembled into a battery is improved; and the prepared positive electrode material does not need to be subjected to a roasting process for two times, the energy consumption is reduced, and the cost is reduced.

The invention discloses a positive electrode active material, a positive electrode plate and a sodium ion battery. The molecular formula of the positive electrode active material is Na<1-x>Cu<h>Fe<k>Mn<1>M<m>O<2y>, in the molecular formula, m is a transition metal site doping element, M is one or more of Li, Be, B, Mg, Al, K, Ca, Ti, Co, Ni, Zn, Ga, Sr, Y, Nb, Mo, In, Sn and Ba, 0<x<=0.33, 0<h<=0.24, 0<=k<=0.32, 0<l <=0.68, 0<=m<0.1, h+k+l+m=1 and 0<=y<0.2. The water content of the positive electrode active material is 6000 ppm or less. By adopting the positive electrode active material provided by the invention, the sodium ion battery has relatively high initial capacity, safety performance and cycle performance at the same time.

The invention discloses a method for realizing metal ion doping and metal oxide surface coating to modify a ternary cathode material jointly by a one-step method, which comprises the following steps:S1. mixing a complexing agent and a ternary cathode material to be dissolved in a solvent, and continuing stirring reaction after ultrasonic wave treatment; 2, adding a metal ion salt solution to be doped and coated into the mixed solution in S1 drop by drop under the stirring state, and continuing stirring e reaction; S3, heating the mixed solution in S2, continuing stirring until the solvent iscompletely volatilized to obtain a mixed powder body; S4, calcinating the powder body obtained in S3 at 400-600 DEG C for 4-6h, and cooling to room temperature to obtain the modified material. The invention adopts a simple process and a method assisted by a complexing agent to prepare a modified ternary cathode material doped with elements on the surface layer and coated on the surface layer of the material in one step. Doping effectively inhibits the crystal structure transformation of the surface layer of the material during the cycle, and the coating layer prevents the direct contact with the electrolyte, inhibits the occurrence of side reactions, and improves the cycling stability of the material. By optimizing the synthesis process, the cost can be effectively saved, and the method has great application prospects.

The invention belongs to the technical field of preparation of a lithium ion battery high-nickel positive electrode material, and particularly provides a lithium phosphate coated lithium ion battery high-nickel positive electrode material and a preparation method thereof. The material and the preparation method are used for overcoming the defects of poor processing performance, harsh requirements on use environment, poor cycling stability, low first-circle coulombic efficiency and sharp reduction of high-temperature performance in the prior art. Lithium dihydrogen phosphate is taken as a coating raw material, and a fast ion conductor lithium phosphate coating layer is generated through in-situ reaction of lithium dihydrogen phosphate and residual alkali (LiOH and Li2CO3) on the surface of a parent material, so that lithium salt residues on the surface of the parent material are greatly reduced, the processing performance is improved, the requirement on a use environment is reduced, the ionic conductivity of the positive electrode material is increased, the number of lithium ions of the positive electrode material is increased, and phase change and interface side reaction are effectively inhibited, therefore, the lithium phosphate coated lithium ion battery high-nickel positive electrode material has excellent cycling stability and specific discharge capacity, and especially can maintain relatively good electrochemical performance at high temperature.

The invention discloses an electrode material, a lithium ion battery, a preparation method and application thereof. The preparation method comprises the following steps: calcining the mixture of a ternary precursor material, a seed crystal and a lithium ion-containing molten salt in an oxygen-containing atmosphere; wherein the molar ratio of the ternary precursor material to the seed crystal is 2:10-10: 1; the ternary precursor material is nickel-cobalt-manganese hydroxide or nickel-cobalt-aluminum hydroxide. The preparation method can control the average diameter of the obtained electrode material within a proper range, so that the interfacial side reaction of the electrode material in the battery cycle process is reduced, the capacity retention rate of the battery is further improved, and better rate capability and cycle stability are obtained.

Provided are a positive electrode active material and an electrochemical device. The positive electrode active material is of a P63mc crystal structure and is a lithium transition metal composite oxide containing Co and an R element, wherein the M element includes at least one of Al, Mg, Ti, Mn, Fe, Ni, Zn, Cu, Nb, Cr, Y, or Zr, the R element includes at least one of F, Cl, and the R element is amolar content of nR; wherein the sum of the molar content of Co and the molar content of M is nCo+M, and the ratio delta of nR to nCo+M is larger than 0 and smaller than or equal to 0.01. The positiveelectrode active material disclosed by the invention is high in crystal structure stability, so that the cycle performance and the thermal stability of an electrochemical device are improved.

The invention provides a method for modifying the surface of a lithium cobalt oxide positive electrode material by a phosphorus-containing compound and the lithium cobalt oxide positive electrode material, and the method comprises the following steps: 1, by taking a lithium cobalt oxide powder material with a layered structure as a matrix, carrying out ball-milling mixing on the lithium cobalt oxide powder material and the phosphorus-containing compound according to a certain proportion to obtain a mixed powder material; 2, in an atmosphere protection environment, heating the mixed powder material to obtain the modified lithium cobalt oxide positive electrode material, wherein the interior of which is lithium cobalt oxide, the near surface of which comprises lithium cobalt oxide crystal lattices and phosphate radical bonds and the surface of which comprises an amorphous coating layer composed of metal ions and phosphate radical groups. According to the preparation method, a phosphorus-containing compound and lithium cobalt oxide are mixed and heated for process control and treatment, so the surfaces of lithium cobalt oxide particles are modified, and the stability of a lithium cobalt oxide structure is enhanced by doping phosphate radicals in surface crystal lattices; and the amorphous coating layer effectively protects the electrode electrolyte interface, reduces the interfaceside reaction, and improves the rate capability and the cycle performance.

Belonging to the technical field of lithium ion batteries, the invention relates to a preparation method of a conductive polymer modified lithium ion battery positive pole piece. The method includes: coating a lithium ion battery positive active material surface with polyvinyl carbazole, then coating a current collector with the polyvinyl carbazole coated positive active material so as to obtain the lithium ion battery positive pole piece. According to the preparation method provided by the invention, the surface of the positive active material is coated with polyvinyl carbazole, thus effectively reducing the interface side reaction between the positive active material and an electrolyte solution, also ensuring Li<+> good transfer efficiency, simultaneously enhancing the electrical conductivity of the positive material, and prolonging the service life of the positive active material. By coating the current collector with the polyvinyl carbazole coated positive active material, the positive pole piece with excellent electrical properties, especially rate performance and stability can be obtained. And polyvinyl carbazole itself has certain caking properties, and can strengthen the oneness of the positive pole piece.

The invention provides an inorganic/organic composite solid electrolyte preparation method, which comprises: mixing polyoxyethylene, a polyvinylidene fluoride-hexafluoropropylene copolymer, a sodium salt, a first filler and an organic solvent to obtain a first slurry, wherein the first filler is a P2 type layered oxide fast ion conductor modified by a silane coupling agent and the particle size of the first filler is 500 nm to 1.5 [mu] m; mixing polyoxyethylene, a polyvinylidene fluoride-hexafluoropropylene copolymer, sodium salt, a second filler and an organic solvent to obtain second slurry, wherein the second filler is a P2 type layered oxide fast ion conductor modified by a silane coupling agent and the particle size of the second filler is smaller than 500nm; coating a substrate with the first slurry, and drying to obtain a layer of solid electrolyte; and coating the second slurry on the surface of the layer of solid electrolyte, and drying to obtain the inorganic/organic composite solid electrolyte.

The invention discloses a modified single crystal ternary positive electrode material and a preparation method thereof. The traditional cross-linking agent is replaced by the hydrogen-bond interaction between the coordination bond formed by the unique beta-diketone group in curcumin and lanthanide series metal ions and the polymer chain, and the sulfonic acid type polymer with high elasticity and ductility is prepared; the generated sulfonic acid can effectively reduce the amount of residual alkali on the surface of the material, has high elasticity and ductility, and can effectively maintain the structure of the material in the repeated charging and discharging process of the battery, and the cycle performance of the battery can be improved.

The invention discloses a composite solid electrolyte membrane based on a metal-organic framework material as well as a preparation method and application of the composite solid electrolyte membrane. The composite solid electrolyte membrane comprises a polymer network and lithium salt, wherein the polymer network is formed by polymerizing polyoxyethylene (PEO) and a metal-organic framework material (MOF) modified by toluene diisocynate (TDI), and the lithium salt is dispersed in the polymer network. According to the composite solid electrolyte membrane based on the metal-organic framework material as well as the preparation method and application of the composite solid electrolyte membrane of the invention, the toluene diisocynate is used as an intermediate, so that the MOF and the PEO are connected through chemical bonds, the ionic conductivity of lithium ions can be greatly enhanced, meanwhile, oxygenolysis of hydroxyl groups of the PEO under high voltage can be avoided, and the high-voltage electrochemical stability is remarkably improved. The preparation method is simple, easy to control, low in cost and easy to industrialize, and has a bright application prospect in the fields of high-specific-energy solid-state battery systems and flexible electronic energy storage devices.

The invention provides a preparation method of a boric acid ester cross-linked self-repairing polymer electrolyte, polyethylene glycol methyl ether methacrylate is selected as a monomer, crystallization is effectively inhibited, the electrochemical performance is improved, boric acid on a cross-linking agent structure containing boric acid is subjected to a condensation reaction to form boric acid ester, vacant p-orbit boron is introduced, and the self-repairing polymer electrolyte is prepared. Lithium ion conduction can be accelerated, a B-O covalent bond can be re-established through an ester exchange reaction of a dynamic boron ester bond, the polymer electrolyte has self-repairing capability, and the cross-linking density of a polymer chain segment can be effectively regulated and controlled by utilizing a cross-linking agent containing boric acid, so that the structure is regulated and controlled; the flexible, efficient, safe and stable boric acid ester cross-linked self-repairing polymer electrolyte is obtained. The polymer electrolyte prepared by the invention is amorphous, has a higher decomposition temperature, a glass transition temperature close to-45 DEG C and a potential stability window of 5.5 V or more, can be self-repaired after being cut and fused into a whole, and has good self-repairing property.

The invention relates to a metal lithium wire and a preparation method thereof. The metal lithium wire has a one-dimensional linear structure, and the outer surface of the metal lithium wire is coatedwith a protective layer. The method takes a conductive array template as a deposition matrix, and the metal lithium wire is prepared in an organic electrolyte system through an electrochemical deposition method. The operation procedure at least comprises the following steps: 1) treating a deposition substrate; 2) performing electrochemical deposition of the metal lithium wire; 3) collecting the metal lithium wire; 4) performing high-temperature passivation treatment on the metal lithium wire. The metal lithium wire prepared by the method has a one-dimensional structure, the expansion and shrinkage of the volume of the metal lithium in the charging and discharging process can be buffered, and the surface coating protection layer can inhibit the reaction between the metal lithium and electrolyte or humid air; meanwhile, the preparation method is safe and simple, and the continuous production of preparation and coating of the metal lithium wire can be realized.

The invention provides a sodium vanadium fluorophosphate electrode coated with a metal oxide layer and a preparation method thereof, and the sodium vanadium fluorophosphate electrode coated with the metal oxide layer is obtained by depositing the metal oxide layer on a Na3V2(PO4)2F3 electrode slice through adoption of an atomic layer deposition method. The preparation method solves the problems ofV and F removal in the cyclic process of the positive electrode material for the sodium-ion battery, improves the cyclic stability of the material in the charge-discharge process, improves the capacity attenuation problem of the material, and has the advantages of uniform and compact coating layer, easily controlled coating amount and remarkably improved yield.

The invention belongs to the technical field of lithium ion battery positive electrode materials, and particularly relates to a preparation method of a single-crystal high-nickel ternary positive electrode material for low-temperature sintering and in-situ coating. The preparation method comprises the following steps: mixing Ni0. 8Co0. 1Mn0. 1 (OH) 2 with a lithium source according to a certain proportion, simultaneously mixing a fluxing agent containing molybdenum and a fluxing agent containing vanadium, and calcining by using a microwave sintering furnace at a certain temperature to prepare the single crystal LiNi0. 8Co0. 1Mn0. 1 O2 material with in-situ coating layer lithium molybdenum vanadate. The direct contact between the electrolyte and the surfaces of the single-crystal LiNi < 0.8 > Co < 0.1 > Mn < 0.1 > O < 2 > particles can be prevented by coating the surfaces with the lithium molybdenum vanadate, so that unnecessary side reactions are reduced, the growth of a CEI film is prevented, and the structural stability of the single-crystal LiNi < 0.8 > Co < 0.1 > Mn < 0.1 > O < 2 > material is improved. And the lithium molybdenum vanadate is a fast ion conductor, so that the lithium ion de-intercalation capability can be enhanced, and the rate capability of the material is further improved.