17results about How to "Small capacity attenuation" patented technology

The invention discloses a preparation method of a composite sodium iron phosphate positive electrode material with high compaction density, which is characterized by comprising the following steps: (1) mixing a sodium source, an iron source, a phosphorus source, a carbon source and the like for preparing the composite sodium iron phosphate positive electrode material in proportion to obtain a precursor aqueous solution; (2) adding a surfactant into the precursor aqueous solution, grinding and uniformly mixing to obtain a homogeneous precursor aqueous solution; (3) carrying out drying granulation on the homogeneous precursor aqueous solution by using a spray drying technology to obtain composite sodium ferric phosphate precursor particles; and (4) performing high-temperature heat treatment on the composite sodium ferric phosphate precursor particles under the protection of inert gas to obtain the composite sodium ferric phosphate positive electrode material. The sodium-ion battery positive electrode material and the electrode plate with high compaction density can be obtained, the reversible specific capacity of the sodium-ion battery is improved, the problem of low gram capacity exertion is solved, the battery capacity is improved, and high-quality sodium-ion battery supply is provided for the field of energy storage.

The invention provides a composite negative pole piece for a sodium-ion battery, a preparation method of the composite negative pole piece and the sodium-ion battery, and belongs to the technical field of battery materials. The composite negative electrode plate comprises a negative electrode current collector and a negative electrode active layer arranged on at least one side surface of the negative electrode current collector; along the direction away from the negative electrode current collector, the surface of the negative electrode active layer comprises a functional layer and a structural layer which are laminated; the functional layer comprises a first negative electrode active material, a first binder and a functional material, and the functional material comprises metal fluoride and / or metal oxide; the structural layer includes a second negative electrode active material and a second binder. According to the composite negative pole piece, the sodium ion deposition and stripping efficiency is improved, the energy density of the sodium ion battery is improved, the capacity fading of the sodium ion battery is slowed down, and the cycle life of the sodium ion battery is prolonged. According to the composite negative pole piece, the sodium ion battery can be used in a wider application field.

The invention discloses a battery negative electrode material and a preparation method thereof, and relates to the technical field of batteries. The battery negative electrode material comprises an inner core, a titanium dioxide coating layer coated on the surface of the inner core, a lithium titanate coating layer coated on the surface of the titanium dioxide coating layer, a carbon coating layer coated on the surface of the lithium titanate coating layer and a polymer coating layer coated on the surface of the carbon coating layer, the inner core comprises a silicon-based negative electrode material; the polymer coating layer comprises at least one of polyaniline, polythiophene and polypyrrole. Under the action of the four coating layers, the integrity of the silicon-based negative electrode material can be kept, direct contact between the silicon-based negative electrode material and an electrolyte is avoided, side reactions are reduced, the capacity fading of the battery in the charge-discharge cycle process is reduced, and the rate capability and the cycle stability of the battery are improved.

The invention relates to the technical field of electrolyte preparation, and discloses a lithium ion battery electrolyte capable of ensuring low-temperature discharge characteristic, which comprises the following components in percentage by mass: 25% of propylene carbonate (PC), 35% of dimethyl carbonate (DMC), 20% of gamma-butyrolactone (GBL), 20% of ethyl acetate, 1.0 mol / L of lithium salt bis (trifluoromethanesulfonimide) (LiTFSI), 3% of additive 1, 3-propane sultone (PS) (mass fraction: 0.1% of sodium hydroxide (mass fraction: 0.1% of sodium hydroxide), and the balance of water. According to the present invention, the low temperature performance of the solution is improved, the unique solvent formula and the unique solvent ratio enable the electrolyte to have good fluidity in the low temperature environment, and the freezing point of the electrolyte is effectively reduced so as to ensure that the lithium ions can smoothly migrate between the electrodes at the low temperature, such that the lithium ion battery performance is improved, and the lithium ion battery performance is improved. The discharge performance of the battery under a low-temperature condition is obviously improved, and the application scene of the lithium ion battery is expanded.

The invention discloses a modified cobaltosic oxide precursor material and a preparation method and application thereof, and relates to the technical field of lithium ion batteries, the modified cobaltosic oxide precursor material comprises a cobaltosic oxide matrix, and a nickel element and a manganese element doped in the cobaltosic oxide matrix; wherein in metal elements of the modified cobaltosic oxide precursor material, the molar ratio of a nickel element is 5%-20%, the molar ratio of a manganese element is 1%-3%, the molar ratio of an aluminum element is 0.8%-3%, the D50 particle size of the modified cobaltosic oxide precursor material is 15-20 microns, the specific surface area of the modified cobaltosic oxide precursor material is 3-5 m < 2 > / g, and the particle size distribution width SPAN value of the modified cobaltosic oxide precursor material is 0.2-0.4. The precursor has the advantages of uniform particle size, no cracking on the particle surface and the like, and the lithium cobalt oxide positive electrode material prepared from the precursor material has excellent cycle stability and cycle life.

This utility model discloses a dual-battery charging and discharging circuit, including: a control module, a first switch module, a second switch module, a first battery, and a second battery; the control module is connected to the first battery and the second battery respectively, and is used to detect the voltage of the first battery and the second battery; the control module is also connected to the first switch module and the second switch module respectively, and is used to control the conduction and cutoff of the first switch module and the second switch module according to the voltage difference between the first battery and the second battery, so as to realize the switching of charging and discharging modes. In the discharging mode, the high-voltage battery is given priority to be powered or the batteries are connected in parallel to be powered; in the charging mode, the low-voltage battery is given priority to be charged or the batteries are connected in parallel to be charged.

The present application provides a negative electrode sheet for a secondary battery and a preparation method thereof, as well as a secondary battery, a battery module, a battery pack and an electric device comprising the negative electrode sheet. The negative electrode sheet of the present application includes a current collector and an active material layer coated on at least one surface of the current collector, the active material layer includes a first graphite layer, a lithium titanate layer and a second graphite layer, the first graphite layer is arranged on at least one surface of the current collector, the lithium titanate layer is arranged on the surface of the first graphite layer, the second graphite layer is arranged on the surface of the lithium titanate layer, and the OI value of the first graphite layer is greater than or equal to 20.0, and the OI value of the second graphite layer is less than or equal to 15.0.

The present invention provides a modified sodium ion battery positive electrode material, comprising a sodium ion battery positive electrode material substrate and a coating layer located on at least part of the surface of the substrate, wherein the coating layer is titanium nitride coated with titanium nitride chloride. The modified positive electrode material provided uses titanium nitride chloride @ titanium nitride coating layer to coat and modify the sodium ion battery positive electrode material, which can significantly improve the structural stability and electrical properties of the sodium ion battery positive electrode material, reduce capacity attenuation, and increase the cycle life of the battery. The present invention also provides a preparation method of the modified sodium ion battery positive electrode material and a sodium ion battery.

The invention belongs to the technical field of battery materials, and discloses a coated and modified layered oxide positive electrode material which comprises a core and a coating layer, and the material of the coating layer is a composite material of Al-doped Ba3NaRu2O9 and MgO. The material of the coating layer provided by the invention can improve the stability of the positive electrode material, reduce the capacity fading of the battery and further improve the cycle performance of the battery. The invention also discloses a preparation method of the coated and modified layered oxide positive electrode material and a lithium ion battery.

The invention relates to the technical field of batteries, and provides an ionic liquid additive for improving the interface stability of a hard carbon negative electrode of a sodium-ion battery and application of the ionic liquid additive in order to solve the problems of low ion transmission rate, poor electrode / electrolyte interface stability and the like of the hard carbon negative electrode in practical application in the prior art. The electrolyte prepared based on the ionic liquid additive comprises electrolyte salt, the ionic liquid additive and an organic solvent, wherein the electrolyte salt is sodium salt; the ionic liquid additive is pyrrolidine type dication ionic liquid, and the organic solvent is one or a mixture of carbonic ester or ether solvents. The electrolyte prepared by the invention not only improves the migration ability of Na < + >, but also promotes the construction of a compact and uniform SEI film. A NaHC half battery and a total battery assembled by an electrolyte prepared from the dicationic ionic liquid additive provided by the invention can significantly improve the long cycle stability. After the NaHC half cell circulates 400 times under the current density of 100 mA / g, the capacity retention rate reaches 90.4%.

The application relates to a polyionic liquid binder suitable for vulcanized polyacrylonitrile and a preparation method and application thereof, which is obtained by carrying out an alkylation reaction and a polymerization reaction on bromo-n-butane and 1-vinylimidazole, and then carrying out an anion exchange reaction on lithium bis(trifluoromethylsulfonyl) imide and sodium anthraquinone-2-sulfonate. The polyionic liquid binder can anchor polysulfide on the polymer chain through the electrostatic interaction between the lone pair electrons in the molecular chain and the polysulfide, effectively inhibits the shuttle effect, contains a quinoid structure which can act as a redox medium to accelerate the electron transfer process and improve the interface kinetic performance of the SPAN positive electrode, has excellent bonding performance and mechanical strength, can significantly improve the structural integrity and electronic conduction continuity of the electrode in the cycle process, and prolongs the cycle life of the electrode. The obtained binder can be widely applied to SPAN-based positive electrodes of lithium ion batteries and provides effective technical support for solving key problems such as volume expansion and poor conductivity of SPAN materials.

The invention belongs to the field of lithium ion batteries, and discloses a high-performance lithium ion battery positive electrode material and a preparation method thereof, the material has a unique microstructure, a novel doping element combination or doping mode is adopted, an electronic structure and a crystal structure of the material are accurately regulated and controlled, a novel surface modification material is introduced, and a stable interface layer is formed. The preparation method comprises the steps of material synthesis, structural characterization, electrochemical performance testing, surface modification and coating research, research on the influence of ion doping on performance, and research on the compatibility with an electrolyte. The overall performance of the lithium ion battery is improved, so that the lithium ion battery has a wider application prospect in the fields of electric automobiles, energy storage systems and the like.

The invention relates to the technical field of negative electrode materials, in particular to a preparation method and application of a low-expansion silicon-carbon negative electrode material.The preparation method comprises the following steps that silicon particles are pretreated in a piranha solution, washed and dried, then magnesium powder is evenly scattered on the surfaces of the silicon particles, heating and cooling are conducted, and porous silicon is obtained; mixing the nano-metal mixed suspension and porous silicon, performing ultrasonic treatment, centrifugally collecting solids, washing, and drying to obtain nano-metal doped porous silicon; adding a carbon source, mixing, grinding, drying, and putting into a tubular furnace to obtain a pyrolysis product; and mixing with polyvinylpyrrolidone, grinding, heating in a tubular furnace, and cooling to obtain the silicon-carbon negative electrode material. According to the preparation method and application of the low-expansion silicon-carbon negative electrode material, local expansion of the porous silicon is effectively relieved through doping of the nano-metal particles, the nano-metal doped porous silicon is wrapped by the carbon source, and expansion of the porous silicon is effectively relieved.

The invention discloses a preparation method for constructing an artificial SEI film on the surface of a lithium negative electrode. According to the method, a mixture of a hydroxyl rare earth metal compound and a carboxyl compound is added, and the rare earth metal-metal organic framework (MOF) composite material is prepared through the steps of stirring, ultrasonic treatment, drying, high-temperature heating and the like. And then, the material and a high-ionic-conductivity binder are coated on a copper foil, and proper pressure is applied to transfer and press the material on a lithium negative electrode, so that an SEI film with high stability and ionic conductivity is formed, and the performance and the safety of the lithium metal battery are effectively improved.

The utility model provides a battery device, a power utilization device and an energy storage device, and belongs to the technical field of batteries. The battery device comprises a box body, single batteries and a heat exchange part, the single batteries and the heat exchange part are both located in the containing cavity, the heat exchange part comprises a heat exchange plate and a bottom plate, a heat exchange channel is formed between the heat exchange plate and the bottom plate, and the heat exchange channel comprises a first heat exchange channel located in a first area and a second heat exchange channel located in a second area; the cross sectional area of at least part of the first heat exchange channels is different from that of the second heat exchange channels, the heat exchange piece further comprises protruding parts, and the protruding parts are located on the first heat exchange channels and connected with at least one of the heat exchange plate and the bottom plate. The cross sectional areas of the first heat exchange channel and the second heat exchange channel are different, and the flows of the heat exchange medium in the first area and the second area are different, so that different heat management can be realized for the battery monomers with different temperatures, the temperature difference between the battery monomers is reduced, the temperature balance of the battery monomers is improved, and the stability of the battery device is improved.

The present invention provides a positive electrode plate and a preparation method thereof and electrical equipment, and relates to the technical field of lithium batteries. The positive electrode plate comprises: a current collector and an active layer arranged on the surface of the current collector; the surface of the current collector contains hydroxyl groups introduced by hydroxyl modification treatment; the active layer comprises carbon quantum dots and a lithium supplement; the surface of the carbon quantum dots contains carboxyl groups introduced by carboxyl modification treatment; the carbon quantum dots on the surface of the current collector and in the active layer are connected by ester bonds formed by esterification reaction between hydroxyl groups and carboxyl groups. The positive electrode plate provided by the present invention achieves a comprehensive improvement in battery performance, including electrical conductivity, ion transport performance, mechanical stability and cycle stability, by introducing carboxyl-modified carbon quantum dots and optimizing the connection method between the active layer and the current collector, and provides an effective technical solution for the development of high-performance lithium-ion batteries.