283results about How to "Good rate characteristics" patented technology

The invention relates to a synthesis and surface modification method of a lithium rich anode material Li1+xM1-xO2 (M is one or more of Ni, Co and Mn, and X is more than or equal to 0 and less than or equal to 1/3) for a lithium ion battery. The method comprises the following steps of: synthesizing a precursor by using a carbonate precipitation method, mixing the precursor and a lithium salt, and calcining for 2 to 20 hours at the temperature of between 800 and 1,100 EG C to obtain a lithium rich material, wherein the prepared lithium rich material has controllable particle size and higher reversible capacity; and dissolving persulfate or sulfate in an amount which is 5 to 80 mass percent of the lithium rich material into deionized water, adding the lithium rich material, stirring for 2 to 100 hours at the temperature of between 25 and 80 DEG C, heating the materials to the temperature of between 100 and 500 DEG C in a muffle furnace, calcining the materials for 2 to 20 hours, fully filtering the obtained materials, and washing off impurities to obtain the surface modified anode material Li1+x-yM1-xO2. The synthesized lithium rich material has controllable particle size; the first charge/discharge efficiency of the lithium rich material and the discharge specific capacity and the cyclical stability under high magnification can be improved; and the method is simple, low in cost, convenient for operation and suitable for industrialized production.

A layered lithium-nickel-based compound oxide powder for a positive electrode material for a high density lithium secondary cell, capable of providing a lithium secondary cell having a high capacity and excellent in the rate characteristics also, is provided. A layered lithium-nickel-based compound oxide powder for a positive electrode material for a lithium secondary cell, characterized in that the bulk density is at least 2.0 g/cc, the average primary particle size B is from 0.1 to 1 μm, the median diameter A of the secondary particles is from 9 to 20 μm, and the ratio A/B of the median diameter A of the secondary particles to the average primary particle size B, is within a range of from 10 to 200. In production of a layered lithium-nickel-based compound oxide powder, which comprises spray drying a slurry having a nickel compound and a transition metal element compound capable of substituting lithium other than nickel, dispersed in a liquid medium, followed by mixing with a lithium compound, and firing the mixture, the spray drying is carried out under conditions of 0.4≦G/S≦4 and G/S≦0.0012 V, when the slurry viscosity at the time of the spray drying is represented by V (cp), the slurry supply amount is represented by S (g/min) and the gas supply amount is represented by G (L/min).

There is provided a positive electrode active material capable of achieving a high volume energy density and yet superior rate characteristics when configured as a positive electrode for lithium secondary batteries. This positive electrode active material comprises a plurality of secondary particles each comprising primary particles composed of a lithium-nickel based complex oxide having a layered rock-salt structure. The plurality of secondary particles have a volume-based average particle diameter D50 of 5 to 100 μm, and at least part of the plurality of secondary particles are coarse secondary particles having a particle diameter of 9 μm or greater. The coarse secondary particles have a voidage of 5 to 25%, and the ratio of through holes among all voids in the coarse secondary particles is 70% or greater.

Disclosed is a method for preparing a lithium-metal composite oxide, the method comprising the steps of: (a) mixing an aqueous solution of one or more transition metal-containing precursor compounds with an alkalifying agent and a lithium precursor compound to precipitate hydroxides of the transition metals; (b) mixing the mixture of step (a) with water under supercritical or subcritical conditions to synthesize a lithium-metal composite oxide, and drying the lithium-metal composite oxide; and (c) subjecting the dried lithium-metal composite oxide either to calcination or to granulation and then calcination. Also disclosed are an electrode comprising the lithium-metal composite oxide, and an electrochemical device comprising the electrode. In the disclosed invention, a lithium-metal composite oxide synthesized based on the prior supercritical hydrothermal synthesis method is subjected either to calcination or to granulation and then calcination. Thus, unlike the prior dry calcination method or wet precipitation method, a uniform solid solution can be formed and the ordering of metals in the composite oxide can be improved. Accordingly, the lithium-metal composite oxide can show crystal stability and excellent electrochemical properties.

The present invention relates to nickel-cobalt-manganese-based compound particles which have a volume-based average secondary particle diameter (D50) of 3.0 to 25.0 μm, wherein the volume-based average secondary particle diameter (D50) and a half value width (W) of the peak in volume-based particle size distribution of secondary particles thereof satisfy the relational formula: W≦0.4×D50, and can be produced by dropping a metal salt-containing solution and an alkali solution to an alkali solution at the same time, followed by subjecting the obtained reaction solution to neutralization and precipitation reaction. The nickel-cobalt-manganese-based compound particles according to the present invention have a uniform particle size, a less content of very fine particles, a high crystallinity and a large primary particle diameter, and therefore are useful as a precursor of a positive electrode active substance used in a non-aqueous electrolyte secondary battery.

An all-solid battery is formed so that an electrode active material layer of at least one of positive and negative electrodes has a composition distribution such that a local volume ratio, expressed by a ratio of a volume of an electrode active material contained in a part of the electrode active material layer with respect to a volume of a solid electrolyte material contained in the part of the electrode active material layer, increases as the part of the electrode active material layer approaches from an interface of the solid electrolyte layer toward an interface of a current collector in a thickness direction of the electrode active material layer, and a voidage of the electrode active material layer increases as the part of the electrode active material layer approaches from the interface of the solid electrolyte layer toward the interface of the current collector in the thickness direction.

Positive electrode active material particles for lithium ion secondary batteries include: a core particle including a first olivine-structured, lithium-containing phosphate compound which includes Fe and/or Mn and Li; and a shell layer attached to the surface of the core particle. The shell layer includes a second olivine-structured, lithium-containing phosphate compound which includes Fe and/or Mn and Li. At least the core particle includes a phosphorous compound represented by the formula (1): Me_mP_nO_p, where Me is Fe and/or Mn, 0<m≦3, 0<n≦3, and 0≦p≦5; a content C1 of the phosphorous compound in the core particle is 0.5 to 3 mol %; and when the shell layer includes the phosphorous compound represented by the formula (1), a content C2 of the phosphorous compound in the shell layer is smaller than the C1.

Disclosed is a lithium-containing metal composite oxide comprising paramagnetic and diamagnetic metals, which satisfies any one of the following conditions: (a) the ratio of intensity between a main peak of 0±10 ppm (Io PPm) and a main peak of 240±140 ppm (I240 pPm), Uoppm/124o PPm), is less than 0.117·Z wherein Z is the ratio of moles of the diamagnetic metal to moles of lithium; (b) the ratio of line width between the main peak of 0±10 ppm (Io PPm) and the main peak of 240+140 ppm (I24o PPm), (W24o PPm/WO ppm), is less than 21.45; and (c) both the conditions (a) and (b), the peaks being obtained according to the 7Li—NMR measurement conditions and means disclosed herein. Also, an electrode comprising the lithium-containing metal composite oxide, and an electrochemical device comprising the electrode are disclosed. The lithium-containing multicomponent metal composite oxide shows crystal stability and excellent physical properties as a result of an improved ordering structure of metals, in which the components of the composite oxide are uniformly distributed. Thus, it can provide a battery having high capacity characteristics, long cycle life characteristics and improved rate characteristics.

The invention provides a lithium manganate composite positive electrode material, a preparing method thereof and a lithium-ion battery. The composite positive electrode material is of a core-shell structure. The inner layer of the composite positive electrode material is an in-situ composite of lithium manganate and nickel-rich concentration gradient type nickel cobalt manganese/lithium aluminate LiMn2O4-LiNi1-x-yCox(Al/Mn)yO2, wherein x is more than 0 and less than or equal to 0.25, and y is more than 0 and less than or equal to 0.15; the outer shell of the composite positive electrode material is a metal oxide coated layer. According to the lithium manganate composite positive electrode material and the preparing method thereof, the in-situ composite of lithium manganate and nickel-rich concentration gradient type nickel cobalt manganese/lithium aluminate is obtained after in-site sintering of a manganese source, a nickel-rich concentration gradient type nickel cobalt manganese/lithium aluminate precursor, and a lithium source, then shell-layer metal oxide is cladded by using spray drying, and finally the composite positive electrode material is obtained by combining a microwave sintering process. The composite positive electrode material provided by the invention has relatively high specific capacity, and excellent high temperature cycling and storage performances.

An electrode active material for an all solid state secondary battery, which is able to have the controlled orientation of a crystal face at the interface between an electrode layer and an electrolyte layer in order to enhance the battery performance, and an all solid state secondary battery including the electrode active material. The electrode active material includes a carbon material having an intensity ratio (P₀₀₂/P₁₀₀) of 600 or less between the X-ray diffraction peak intensity P₀₀₂ in the (002) plane and the X-ray diffraction peak intensity P₁₀₀ in the (100) plane, which are obtained when a surface of a compact prepared by compression molding of a powder of the carbon material at a pressure of 110 MPa is irradiated with X-ray. The all solid state secondary battery includes a positive electrode, a negative electrode, and a solid electrolyte, and the negative electrode contains the electrode active material.

The invention provides a preparation method of a graphene quantum dot/nanometer silicon negative electrode material for a lithium-ion battery. Amino acid functional graphene quantum dots are prepared by high-temperature pyrolysis of a mixture of a citric acid and an amino acid as a carbon source; and then a graphene quantum dot/nanometer silicon compound is obtained by coating the graphene quantum dots on the surface of nanometer silicon particles. A research shows that the electron/ion conductivity of a silicon negative electrode is improved by introduction of the graphene quantum dots; and the compound has significantly improved specific capacitance and high rate capability and cycling stability as the negative electrode material for the lithium-ion battery. The preparation method can be widely applied to various high-capacity lithium-ion batteries.

The invention relates to a carbon-clad spinel lithium titanate Li4MxTiyO12 material used as a lithium ion battery cathode material, a production method and an application thereof. The cathode material is spinel type Li4MxTiyO12 or a mono or multiple other metallic element-doped compound Li4MxTiyO12. A synthetic method comprises the following steps: mixing an organic titanium solution and lithium salt liquid to prepare sol; aging the sol to obtain a lithium titanate gel predecessor; calcining the gel predecessor, and being conversed to the spinel lithium titanate material with nano size; or comprises the following steps: dispersing the prepared lithium titanate in a carbon source organic solution, removing the solution, and calcining to obtain the spinel lithium titanate/carbon composite material with nano size. Compared with lithium titanate Li4Ti5O12 prepared by a conventional method, the spinel lithium titanate material has better multiplying power characteristic, when the spinel lithium titanate material is used as a lithium ion battery cathode, the power performance of the cell can be obviously increased.

A slurry composition for electrode comprising a binder, an active material, and a liquid medium, characterized in that the binder comprises a polymer (X) comprising 60 to 95 mole % of repeating units derived from acrylonitrile or methacrylonitrile and 5 to 30 mole % of repeating units derived from at least one kind of a monomer selected from 1-olefins and compounds represented by the following general formula (1): CH₂═CR¹—COOR² wherein R¹ represents a hydrogen atom or a methyl group and R² represents an alkyl group; and the liquid medium is capable of dissolving the polymer (X). The slurry composition allows the manufacture of a lithium ion secondary battery having enhanced capacity and good charge-discharge cycle characteristics and good charge-discharge rate characteristics.

The invention relates to the technical field of preparation of nanometer materials, and discloses a functionalized polydopamine derived carbon layer coated carbon substrate preparation method and application. The preparation method comprises the following steps: 1) immersing a carbon substrate into a trihydroxymethyl aminomethane aqueous solution, the pH value of which is adjusted to be alkaline, and then, reacting with dopamine hydrochloride to obtain a polydopamine coated carbon substrate; 2) carrying out high-temperature carbonization on the obtained polydopamine coated carbon substrate to obtain a polydopamine derived carbon layer coated carbon substrate; and 3) enabling the obtained polydopamine derived carbon layer coated carbon substrate to react with a bimetallic saline solution to obtain a functionalized polydopamine derived carbon layer coated carbon substrate. The functionalized polydopamine derived carbon layer coated carbon substrate is stable in structure, is high in electrochemical activity, and has a series of advantages of high specific capacitance and good rate capability and the like when serving as the electrode material of a super capacitor; and the preparation method thereof is simple and easy to operate.

The present invention provides a positive electrode active material for lithium ion battery having good rate characteristics. The positive electrode active material for lithium ion battery has a layer structure expressed by a composition formula: Li_x(Ni_yMi_1-y)O_z, wherein M represents Mn and Co, x represents 0.9 to 1.2, y represents 0.6 to 0.9, and z represents 1.8 to 2.4. The positive electrode active material has a particle size ratio D50P/D50 of 0.60 or more, wherein D50 is the average secondary particle size of the positive electrode active material powder, and D50P is the average secondary particle size of the positive electrode active material powder after pressing at 100 MPa. The positive electrode active material contains 3% or less particles having a particle size of 0.4 μm or less in terms of the volume ratio after pressing at 100 MPa.

The invention relates to a preparation method of a manganese dioxide/carbon material/conducting polymer composite material. The preparation method comprises the following steps: 1, water phase comprising an aqueous solution of potassium hypermanganate and a colloidal solution of a carbon material and organic phase formed by dispersing monomers of the conducting material in an organic solvent are subjected to the interfacial oxidative polymerization to obtain the manganese dioxide/carbon material/conducting polymer composite material; and 2, the manganese dioxide/carbon material/conducting polymer composite material obtained from step 1 is calcined with the existence of an inert gas to obtain the target composite material. The outstanding advantage of the preparation method is that, by subjecting the composite materials of the conductive materials, such as the manganese dioxide, the carbon material, and/or the conducting polymer, to the post-treatment of calcination, not only is the carbon material reduced, but also hydrate can be removed from the manganese dioxide to form a stable crystal structure, so that the electrochemical performance of the composite material is improved.

This invention provides a lithium nickel manganese cobalt composite oxide having a composition of LiaNixMnyCozO₂ (x+y+z=1, 1.05<a<1.3), wherein, in the data obtained by measuring a Raman spectrum of the composite oxide, the peak intensity of an Eg oscillation mode of a hexagonal crystal structure located at 480 to 495 cm⁻¹ and the peak intensity of an F2g oscillation mode of a spinel structure located at 500 to 530 cm⁻¹ in relation to the peak intensity of an A1g oscillation mode having a hexagonal crystal structure in which the main peak is located at 590 to 610 cm⁻¹ are respectively 15% or higher and 40% or lower than the peak intensity of the A1g oscillation mode of a hexagonal crystal structure as the main peak. Thereby, the Raman spectrum can be used for the identification of the crystal structure to clarify the characteristics of a positive electrode precursor composed of lithium nickel manganese cobalt composite oxide. In particular, it is possible to obtain lithium nickel manganese cobalt composite oxide and a lithium rechargeable battery superior in rate characteristics and cycle characteristics.

The invention relates to a lithium-ion-battery composite material and a preparing method of a composite electrode of a lithium ion battery. Nanometer silicon is added into a dopamine hydrochloride solution, and a polydopamine wrapping layer is formed on the surface of silicon; meanwhile, graphene quantum dots are prepared with the one-step solvothermal method, and are doped into sodium alginate binding agent, and a composite electrode material is prepared. In the lithium-ion-battery composite material and the preparing method of the composite electrode of the lithium ion battery, the polydopamine wrapping layer can buffer enormous volume expansion of a silicon ball, and the stability of a silicon-based cathode material is effectively improved. As the graphene quantum dots are doped, a binding agent layer has the higher mechanical performance and the elasticity, the product has the more lasting swelling property in electrolyte accordingly, and can develop the reversible buffering effecton enormous volume changes of silicon after multiple times of cycling, and the structural integrity of an electrode in the charging and discharging process is further guaranteed; meanwhile, the graphene quantum dots have certain conductivity, and therefore the conductivity of the binding agent layer is improved. The electrode shows the good electrochemical performance, and can be widely applied to various high-capacity lithium ion batteries.

The invention belongs to the technical field of a new energy material, specifically a preparation method of a vanadium tetrasulfide/graphene composite material used for an electrode of a sodium ion battery. By adopting a hydrothermal synthesis method and by adopting layered graphene as a template, vanadium tetrasulfide is grown on the layered graphene template (or vanadium tetrasulfide particles are coated with graphene) so as to form the vanadium tetrasulfide/graphene composite material; the method is simple in process, low in cost, high in repeatability, and suitable for a commercial application of the electrode material of the sodium ion battery; according to the preparation method, by virtue of a graphene thin film sheet layers, the nanometer vanadium tetrasulfide particles are connected between the sheet layers to form a stable solid electrolyte interface film, thereby effectively improving conductivity of the composite electrode material, and showing high rate capability and cycle stability; and the reversible specific capacity in charging and discharging cycles at the current of 0.2A.g<-1> can reach 580mAh.g<-1>, and high-current charging and discharging capability of as high as 20A.g<-1> can be realized, so that the commercial electrode application of the sodium ion battery can be satisfied.

The invention provides a cathode material of a secondary battery. The cathode material comprises LiMPO4 and Lil+xMnyNizCo1-x-y-zO2, wherein M is any one of Fe, Co, Ni and Mn, x is more than 0 and less than 0.3, y is more than 0.5 and less than 0.8, and z is more than 0 and less than 0.3; and LiMPO4 is accumulated or dispersed on the surface of the Lil+xMnyNizCo1-x-y-zO2. The cathode material provided by the invention is not reduced in electron conduction rate. The secondary battery prepared from the cathode material has high cyclability and multiplying power property. The invention also provides a preparation method of the cathode material as well as an anode and the secondary battery.

The invention relates to a silicon-containing lithium ion battery with high energy density. The lithium ion battery comprises a positive electrode, a silicon-containing negative electrode, a fluorine-containing electrolyte, a diaphragm, electrode lugs and a packaging material. The silicon-containing negative electrode takes a silicon-based material as a whole or a part of electrochemical active substances. The electrolyte contains lithium salt, a non-aqueous organic solvent capable of dissolving the lithium salt, an SEI film-forming additive and hydrofluoroether. The solubility of the lithiumsalt in the non-aqueous organic solvent capable of dissolving the lithium salt is higher than 2 mol/L. The solubility of the lithium salt in the hydrofluoroether is lower than 0.3 mol/L, wherein the non-aqueous organic solvent capable of dissolving the lithium salt is mutually dissolved with the hydrofluoroether, the non-aqueous organic solvent capable of dissolving the lithium salt and the liquidSEI film-forming additive are mutually dissolved, so the solid SEI film-forming additive can be dissolved. The silicon-containing lithium ion battery has the advantages of high energy density, long cycle life, good rate capability, high safety performance, difficulty in expansion and deformation and the like.

Provided is a separator made of a laminated porous film in which a heat-resistant layer that comprises a heat-resistant resin and a shut-down layer that comprises a thermoplastic resin are laminated, wherein the heat-resistant layer further comprises two or more fillers, and the value of D₂/D₁ is 0.15 or less where among values each obtained by measuring the average particle diameter of particles that constitute one of the two or more fillers, the largest value is let be Di and the second largest value is let be D₂.

A positive electrode active material is provided that has a high capacity, a low irreversible capacity, an excellent initial charge/discharge efficiency, and excellent rate characteristics. This positive electrode active material comprises a hexagonal lithium nickel complex oxide having a layer structure and represented by the general formula Li_xNi_1-y-zCo_yM_zO₂ (0.98≦x≦1.04, 0.25≦y≦0.40, 0≦z≦0.07, and M is at least one element selected from Al, Ti, Mn, Ga, Mg, and Nb), wherein a lithium occupancy rate in a lithium main layer as obtained by Rietveld analysis from the x-ray diffraction pattern is at least 98.7%, and a crystallite diameter as calculated from the peak for the (003) plane in x-ray diffraction is 50 to 300 nm.