376results about How to "Improve rate discharge performance" patented technology

A positive active material is provided which can give a battery having a high energy density and excellent high-rate discharge performance and inhibited from decreasing in battery, performance even in the case of high-temperature charge. Also provided is a non-aqueous electrolyte battery employing the positive active material. The positive active material contains a composite oxide which is constituted of at least lithium (Li), manganese (Mn), nickel (Ni), cobalt (Co), and oxygen (O) and is represented by the following chemical composition formula: Li_aMn_bNi_cCo_dO_e (wherein 0<a≦1.3, |b−c|≦0.05, 0.6≦d<1, 1.7≦e≦2.3, and b+c+d=1). The non-aqueous electrolyte battery has a positive electrode containing the positive active material, a negative electrode, and a non-aqueous electrolyte.

The invention provides a polymer porous membrane, a preparation method of the polymer porous membrane, a polymer electrolyte, a polymer battery and a preparation method of the polymer battery. A carbon material is dispersed in the polymer porous membrane, so that the degree of crystallization of a polymer which constitutes the polymer porous membrane is lowered and the liquid absorption of the polymer porous membrane is increased; the liquid absorption rate, liquid holding capability and ionic conductivity of the polymer porous membrane are increased; interface impedance is reduced, battery magnification discharging performance and the circulating performance of the battery are enhanced; simultaneously, the battery prepared by the method has excellent high temperature circulation and storage performance and low expansion ratio at a high temperature and further meets the development requirement of the polymer battery. Simultaneously, the preparation method is simple and is easy to implement and the prepared battery has high performance.

The invention relates to a nanoscale lithium titanate compound and a preparation method thereof. The nanoscale lithium titanate compound is prepared by following steps: a lithium compound, a titanium compound and a doped element compound are mixed according to a molar ratio of 0.75-0.80:1:0:0.05 of Li to Ti to doped elements so as to form a mixture A; the mixture A and a complexing agent are mixed according to a weight ratio of 1:0.1-10 and dissolved in water to form a mixture B; and the mixture B and a carbon nanotube dispersion C are mixed to form the nanoscale lithium titanate compound coated by carbon nanotubes with a nanoscale grain size. The preparation method comprises the following steps: mixing the mixture B and the carbon nanotube dispersion C; heating an obtained mixture in nitrogen at 100-200 DEG C for 1-2 hours to obtain gel; and sintering the obtained gel in inert atmosphere at 500-1,000 DEG C for 5-48 hours to obtain the powdered lithium titanate compound. The lithium titanate compound is nanoscale lithium titanate coated by the carbon nanotubes, has fine and even grain and high purity and has the characteristics of higher charge and discharge capacity, good rate discharge performance, good cycle performance and good safety performance, and the like, thus the lithium titanate compound is an ideal anode material for manufacturing a lithium ion battery.

The invention relates to an application of a porous carbon material with a grading pore structure in a lithium-air cell anode, and is characterized in that the carbon material has mutually communicated grading pore structure distribution which has a mesoporous structure for depositing the discharge products and a macroporous structure suitable for transmission of oxygen and an electrolyte. When the carbon material is taken as a material of the lithium-air cell anode, the space utilization rate of carbon material can be increased at maximum limitation during a charge and discharge process, specific discharge capacity, voltage platform and multiplying power discharge capability of the cell can be effectively increased, so that the energy density and power density of the lithium-air cell can be increased. The porous carbon material has the advantages that the preparation technology is simple, the material source is wide, the grading pore carbon material pore structure enables regulation and control, the regulation and control modes are various, and the doping of metal/metal oxide can be easily and simultaneously realized.

The invention relates to a novel modified non-woven fabric lithium-ion battery diaphragm. The diaphragm comprises a modified non-woven fabric base material and a filling agent compounded on the modified non-woven fabric base material, wherein the modified non-woven fabric base material comprises a low-smelting-point material and a high-smelting-point material; the low-smelting-point material is subjected to melt crystallization treatment and the weight of the high-smelting point material accounts for 85-99.9% of the total weight of the base material; the residual amount is the low-smelting point material; the filling agent compounded on the modified non-woven fabric base material comprises organic polymer, a first filling material and/or a second filling material. The invention further relates to a preparation method of the battery diaphragm. The preparation method sequentially comprises the following steps: manufacturing a non-woven fabric fiber layer; manufacturing the modified non-woven fabric base material; preparing filling agent slurry; filling; removing a solvent; and carrying out post-treatment. The method is simple in operation and low in cost; a prepared product is low in water content, good in chemical stability and high in mechanical strength; the finished product rate of a battery is increased, the service life is prolonged and the safety is improved.

Disclosed is a phosphorus-doped lithium iron phosphate positive electrode material and a preparation method of the same, which relates to a positive electrode materials of lithium ion batteries. The present invention provides a phosphorus-doped lithium iron phosphate positive electrode material of lithium ion batteries with higher charge-discharge capacity, excellent multiplying power performance and cycle performance, and a preparation method of the same. The positive electrode material has a formula of LiyFe(P1-xMx)O4, wherein M is doping element of Ge, Sn, Se, Te or Bi. The preparation method comprises the steps of mixing the ferrite and phosphate with dopant; adding at least one of the water, alcohol, acetone serving as ball mill solvent; scrubbing and filtrating after ball milling; vacuum drying the filtration product to obtain the intermediate product which is mixed with lithium salt; adding ball mill solvent to ball mill again; drying the product and then heating calcining in the presence of inert gas or reducing atmosphere to obtain doping type lithium iron phosphate LiyFe(P1-xMx)O4 powder.

The invention relates to a preparation technology of a battery anode material and a related automobile battery and particularly discloses a preparation method of lithium ion battery anode material lithium manganate. The method comprises the following steps: using lithium source, Mn3O4 and nanoscale doping metal additive as raw materials for proportioning, then presintering Mn3O4 or the Mn3O4 processed by ball milling, mixing the presintered Mn3O4 with the mixture of lithium source and metal additive; performing the first sintering and second sintering to the mixed raw material; and finally classifying and screening the sintering product to obtain the spinel lithium manganate product with the required grain size. The invention also discloses an automobile lithium ion battery which is assembled by using the spinel lithium manganate prepared by the method of the invention as anode and using graphite as cathode. The preparation method of the invention has simple operation and environmental friend; and the prepared lithium manganate product has excellent product performance.

The invention discloses a conductive agent dispersion liquid and a preparation method thereof. The conductive agent dispersion liquid contains a conductive agent, a solvent and a dispersion agent, wherein the dispersion agent contains aromatic rings and can be bound with the surface of the conductive agent by Van der Waals force among molecules and pi-pi action force between planes; and the solubility in the first solvent at the temperature of 25 DEG C is not smaller than 10wt%. The invention also discloses an electrode slurry and a preparation method thereof, and a battery electrode prepared from the electrode slurry and a battery. As using the matter which contains the aromatic rings and can be bound with the surface of the conductive agent by Van der Waals force among molecules and pi-pi action force between planes as the dispersion agent of the conductive agent, the battery capacitance, the charging and discharging capacitance and the rate discharge property are effectively enhanced.

The invention provides a graphene-based composite ternary material. The ternary material comprises graphene and a nickel-cobalt-manganese ternary material, wherein the graphene is prepared by sintering oxidized graphene, is composed of single-layered graphene slices or multi-layered graphene slices whose layer number is less than 10, and accounts for 0.1% to 10.0% of the total weight of the composite ternary material; and the nickel-cobalt-manganese ternary material has a primary particle structure or a secondary particle structure, has a molecular formula of Li(Ni<x>Co<y>Mn<z>)O2, wherein the sum of x, y, and z is equal to 1, and x, y, and z are all in a range of 0 to 1, and accounts for 90.0% to 99.9% of the total weight of the composite ternary material. The graphene slices are freely stacked in the graphene, thus conductive nets and cavities are formed, and the nickel-cobalt-manganese ternary material particles are embedded into the cavities between the nano graphene layers through a chemical precipitation method. The invention also provides a preparation method of the graphene-based composite ternary material.

The invention relates to a nano ferrous silicate lithium material and a preparation method thereof. The preparation method comprises the following steps: a lithium source, an iron source, a silicate source and a doping element compound are dissolved into a water solution which contains a complexing agent according to a certain stoichiometric ratio, a high-conductivity carbon nano tube dispersed by an auxiliary agent is added into the water solution and used as a wrapping material, an obtained solution is heated under the temperature of 100-200 DEG C for 1-3 hours to obtain gelatin, the obtained gelatin is sintered in an inert atmosphere furnace, the reaction temperature is 600-900 DEG C, and the reaction time is 3-16 hours. The invention effectively controls the chemical composition, the phase composition and the grain diameter of ferrous silicate lithium, and the obtained ferrous silicate lithium is nano ferrous silicate lithium wrapped by the carbon nano tube and has small and uniform grains with high purity quotient, higher charge-discharge capacity and good multiplying power property and circulation property, thus the ferrous silicate lithium is an ideal material for producing lithium ion batteries.

The invention relates to the field of the processing of lithium-ion battery diaphragms, and discloses a preparation method for a microporous diaphragm. The preparation method for the microporous diaphragm includes the following steps: 1) a principal polyolefin resin and an auxiliary additive are uniformly stirred through a stirring mixer to obtain a mixture I; 2) the obtained mixture I is added into an extruder to be uniformly melted and plasticized into a melt; 3) an intermediate diaphragm is prepared from a cast piece of the melt extruded from a die head; 4) annealing treatment is performed on the intermediate diaphragm under bi-directional micro-tension; 5) the annealed intermediate diaphragm is stretched longitudinally to prepare the diaphragm with a microporous structure. The invention further discloses the microporous diaphragm prepared through the method, which consists of the principal polyolefin resin with a weight percentage of 75 to 99.9 percent and the auxiliary additive with a weight percentage of 25 to 0.1 percent. The preparation method disclosed by the invention has the advantage that the lithium-ion battery diaphragm with a uniform structure, the specific microporous structure and high safety performance can be prepared.

The invention discloses a rapid forming method of a lithium ion power battery, which is characterized by comprising the following steps of: 1. precharging; 2. settling and aging; and 3. charging by adopting an intermittent depolarized single-stage impulse charging mode until charge is finished. Because the forming process of the invention adopts the intermittent depolarized single-stage impulse charging mode, the impedance of an SEI (Solid Electrolyte Interface) membrane is lowered, thereby reducing the internal resistance of the battery and improving the rate discharge performance of the lithium ion power battery. Because the forming process of the invention adopts an impulse current with a lower frequency, the battery can be naturally depolarized within the impulse-off time, thereby lowering the polarizing effect, stabilizing the charging voltage, improving the charging efficiency, simultaneously avoiding the high requirement brought by a high frequency impulse current charging mode for equipment, improving the utilization efficiency of electric energy and greatly lowering the production cost. The step of precharge is adopted to facilitate the formation of the stable SEI membrane, thereby improving the performance of the battery.

The invention discloses an electrolyte additive and an apparition thereof. The additive contains a thiophene compound. The additive, which is used for a lithium ion battery, is capable of inhibiting the continuous electrochemical oxidation reaction of the electrolyte and the anode material, improving the electric conductivity of the anode material, improving the cycle performance and the high current discharge performance of the battery, and improving the safety performance and the rate performance of the battery.

The invention provides an electrolyte of a li-ion secondary battery and a li-ion secondary battery which is provided with the electrolyte. The electrolyte comprises non-aqueous solvent and electrolyte which is mixed lithium salt; wherein, the mixed lithium salt comprises lithium salt A, lithium salt B and lithium salt C; the lithium salt A is LiBOB; the lithium salt B is LiCF3SO3 and/or Li (CF3SO2)2N; the lithium salt C is one or more than one chosen out of LiPF6, LiBF4, LiCIO4, LiAsF6 and lithium halide. By adopting the electrolyte and the battery provided by the invention, the high-temperature storage performance, the high-temperature circulation performance, discharging performance in different ratios and safety performance are all obviously improved.

The invention relates to a method for high-power lithium ion cell and amorphous-carbon to coat positive material. Wherein, the cell positive shell comprises a positive active material with shell-nucleus structure; the shell structure has amorphous material while the nucleus is spherical material with D50 size less than 10ª–m; the negative electrode comprises active material and carbon fiber, and the dual-surface coating weight for positive and negative active materials is 10-30mg/cm2 and 4.8-14.5mg/cm2 respectively. The method for amorphous-carbon comprises: 1) dipping the positive material into sweet water; 2) stirring, filtering; 3) drying; 4) carbonizing in inert gas atmosphere at 600-1000Deg; 5) breaking and screening. This invention reduces internal resistance of electrode, increases discharge property of cell, and economical to process.

The invention relates to a flame-retardant electrolyte for a secondary lithium-sulfur battery and a preparation method for the flame-retardant electrolyte. The flame-retardant electrolyte comprises a lithium salt, an organic solvent and a fire retardant, wherein the concentration of the lithium salt is 0.5-5mol/L in the electrolyte; the fire retardant is phosphonitrile fluoride fire retardant, which accounts for 0.1-20% of the total flame-retardant electrolyte based on mass percentage; the lithium salt is added to the organic solvent to be uniformly stirred to prepare the electrolyte; and then the fire retardant is added to the electrolyte to be continuously stirred and uniformly mixed to obtain the flame-retardant electrolyte for the secondary lithium-sulfur battery. Compared with the prior art, the flammability of the electrolyte added with the phosphonitrile fluoride additive is greatly lowered, and the influence on the conductivity is relatively low; according to the secondary lithium-sulfur battery assembled by the electrolyte containing the phosphonitrile fluoride fire retardant, the electrochemical performance of the secondary lithium-sulfur battery is obviously improved, and an effect of giving consideration to both of the flame-retardant effect and the electrochemical performance can be achieved.

The invention relates to A2B7 type RExYnNiz-a-bMnaAlb hydrogen storage alloy. The alloy is good in pressure-composition-isothermality, and has a maximum hydrogen storage amount of up to more than 1.36 wt.% under usual conditions. The alloy of the invention has better electrochemical performance as a hydrogen storage electrode and better gas-phase hydrogen absorption and desorption performance as a hydrogen storage material than traditional LaNi5 type hydrogen storage alloy; the alloy contains no magnesium element in the composition, so the preparation method of the alloy is simple and safe when compared with that of traditional rare earth-magnesium-nickel-based A2B7 type hydrogen storage alloy.