37results about "Negative electrodes" patented technology

The present invention discloses negative electrode for zinc nickel secondary batteries and the fabrication methods. These negative electrodes contain hydrophobic porous conductive granules such as carbon black granules with a hydrophobic material adsorbed. The fabrication methods for these negative electrodes include the following steps: adding a hydrophobic material to conductive porous granules such as granules in an aqueous solution; stirring said aqueous solution with said conductive porous granules and said hydrophobic material; fabricating the active material with said aqueous solution with said conductive porous granules and said hydrophobic material; and forming said negative electrode with said active material. Batteries with negative electrodes that are embodiments of this invention or are fabricated by the method of this invention are efficient in the recombination of oxygen at the electrodes during charging have low internal pressure, and are not subjected to electrolyte leakage.

The invention relates to a graphite negative electrode material of a low-temperature lithium ion battery and a preparation method thereof. The graphite negative electrode material of the low-temperature lithium ion battery comprises graphite and a fast ion conductor coated on the graphite surface; The oxidation-reduction potential of the fast ionic conductor is higher than that of graphite. The preparation method comprises the following steps of: wet ball milling the original graphite powder, drying the mixed liquid into powder by a spray dryer to obtain graphite powder with smaller particle size, intercalating the graphite powder, coating the surface of the graphite powder, and obtaining graphite negative electrode material for low-temperature lithium ion batteries. As in that anode material structure, particle size of the graphite can be controlled, diffusion distance of lithium ion is shorten, graphite interlayer spacing is increased after intercalation, that ion diffusion ability of the electrode material at low temperature can be obviously improved, the integral conductivity can be improved by intercalated metal or highly conductive substance between graphite layers, and a stable and uniform SEI film can be formed by coating a fast ionic conductor on the graphite surface, the lithium ion diffusion ability can be improved, and the interface property at low temperature can be improved. This material can also be used as an ideal cathode material for sodium ion batteries and high performance supercapacitor materials.

The invention relates to a method for preparing a ferric vanadate-graphene negative electrode composite material. The method comprises the following steps: dispersing sheet layers of graphene, forming ferric vanadate on the surface of graphene, growing and performing after-treatment on the ferric vanadate attached to the surface of graphene. According to the method disclosed by the invention, the sheet layers of graphene are dispersed, so that the ferric vanadate is uniformly attached to the surface of the graphene. Therefore, the ferric vanadate-graphene negative electrode composite material is uniform in texture and high in dispersity, the performance is greatly improved, and hydrogen peroxide is added into graphene turbid liquid, so that reaction is carried out on the surface of the uniformly dispersed graphene, functional groups are generated, a negative ion state is formed, ferrous iron ions are easily adsorbed, the reaction rate is accelerated, the adsorption rate is increased, and the ions react with vanadate on the graphene surface so as to form uniform particles. The ferric vanadate-graphene negative electrode composite material disclosed by the invention has low discharge voltage and extremely high discharge capacity, the raw materials are wide in source, and the cost is reduced.

In a nonaqueous secondary battery including a pressure-operated current interrupt device, a ratio (Vt/Cr) of a sum Vt (cm³) of an effective pore volume Vp of the positive electrode active material layer, an effective pore volume Vn of the negative electrode active material layer, and a pore volume Vs of the separator to a volume Cr (cm³) of a remaining space in the battery case is 0.92 to 1.05. The volume Cr of the remaining space in the battery case is calculated by subtracting a volume Ce of the electrode body, a volume Cna of the nonaqueous electrolytic solution, and a volume Cc of auxiliary components from a volume Ct of the battery case. The remaining space volume Cr (cm³) is 14.8 vol % or higher of the volume Ct (cm³) of the battery case.

The invention relates to the technical field of inorganic materials, and discloses a preparation method for a ferrous carbonate/graphene composite material. The preparation method comprises the steps of: I. mixing graphene materials, water-soluble ferrite, urea and water to form a suspension, wherein the mass ratio of the graphene materials to the water-soluble ferrite is (0.02-0.2):1, and the amount-of-substance concentration ratio of the urea to the water-soluble ferrite is (20-100):1; II. putting the suspension into a reaction kettle, controlling the temperature to be 100-180DEG C, and carrying out hydrothermal reaction for 4-12h to obtain the ferrous carbonate/graphene composite material. The invention further provides a lithium ion battery prepared by taking the ferrous carbonate/graphene composite material as a negative electrode material. By being synthesized through low-temperature hydrothermal reaction, the ferrous carbonate/graphene composite material is high in specific capacity and good in cycling performance, and has excellent development prospects after being applied to the negative electrode materials of the lithium ion battery.

A method of producing a powder mass for a lithium battery, the method comprising: (a) mixing graphene sheets and an elastomer or its precursor in a liquid medium or solvent to form a suspension; (b) dispersing a plurality of particles of an anode active material in the suspension to form a slurry; and (c) dispensing the slurry and removing the solvent and/or polymerizing/curing the precursor to form the powder mass, wherein the powder mass comprises multiple particulates of the anode active material, wherein at least one of the particulates is composed of one or a plurality of the particles encapsulated by a thin layer of graphene/elastomer composite having a thickness from 1 nm to 10 μm, a lithium ion conductivity from 10⁻⁷ S/cm to 10⁻² S/cm and an electrical conductivity from 10⁻⁷ S/cm to 100 S/cm.

The invention belongs to the technical field of synthesis of battery materials, and particularly relates to a negative electrode material and a preparation method thereof and a secondary battery. According to the negative electrode material, graphite serves as a core structure, a silicon layer, a carbon coating layer and a carbon nanotube are sequentially arranged on the surface of the core structure in the direction away from the core structure, and the length-diameter ratio of the carbon nanotube is larger than 3000. According to the negative electrode material disclosed by the invention, the carbon nano tube with high length-diameter ratio is arranged at the outermost portion, so that the conductivity can be improved, and a cage structure can be formed during mixing and stirring to buffer the volume change of the silicon layer; and the negative electrode material disclosed by the invention has the advantages of high initial coulombic efficiency and specific capacity, low irreversible capacity and good cycling stability and conductivity.

The invention provides a method for preparing a lithium battery negative electrode by compounding silicon, carbon and silicon dioxide in an extruder, which comprises the following steps: carrying outmixed heat treatment on nano silicon powder and nano silicon dioxide to obtain silicon monoxide steam, introducing the silicon monoxide steam into a twin-screw extruder by using a flow guide pipe, then respectively adding graphite powder, CMC, SBR, CTAB, PTFE and paraffin powder into the twin-screw extruder for mixing and extrusion, and then screening the extruded powder through a screen at a discharge port to obtain the product. According to the method provided by the invention, the silicon monoxide steam, the graphite powder and other auxiliaries are mixed and extruded in the screw extruderto obtain the effectively coated silicon monoxide/carbon negative electrode material, so that the volume effect of the silicon-based negative electrode material in use can be effectively avoided, andmeanwhile, the whole preparation process is simple and controllable; and the problems of high equipment requirement and complex preparation process in the original process are solved, and the method has a wide application prospect.

The invention relates to a preparation method of a chitosan-based spherical negative lithium ion battery carbon electrode. The preparation method comprises the following steps: taking chitosan as a raw material, dissolving the chitosan in a certain proportion of hydrochloric acid solution, stirring at a room temperature for 3 hours, then heating to a certain temperature, stirring for several hours, adding a uniformly mixed solution into a polytetrafluoroethylene-lined stainless steel reaction kettle, sealing, then reacting at the temperature of 120-200 DEG C for 5-12 hours, naturally cooling to a room temperature, filtering, washing and drying to obtain hydrothermal charcoal with the particle size distribution of 1-6 microns, then performing high-temperature carbonization in an inert atmosphere to obtain the nitrogen-containing spherical negative carbon electrode. By the preparation method, the raw material is cheap and easy to obtain, a synthesis technology is simple and easy to implement, a negative electrode material is stable and non-toxic in air, is used as the negative electrode material of a lithium ion battery and shows superior electrochemical performance.

The embodiment of the invention discloses a silicon monoxide composite material, a preparation method thereof and a lithium ion battery, and the preparation method comprises the following steps: introducing a protective gas into a vapor deposition furnace, and preheating a silicon monoxide raw material at the same time, so that part of the silicon monoxide raw material is subjected to a disproportionation reaction; and continuously introducing protective gas and carbon source gas, and carrying out chemical vapor deposition on the preheated silicon monoxide raw material so as to form the carbon nanotubes on the surface of the silicon monoxide. According to the embodiment of the invention, the carbon nanotube can be catalytically grown on the surface of the silicon monoxide through the in-situ self-generated catalyst, the conductivity and the first coulombic efficiency of the silicon monoxide are improved, and the preparation process is simple.

The invention provides a preparation method of a double-layer zinc stannate nanosheet negative electrode material and a product and application of the double-layer zinc stannate nanosheet negative electrode material. Zinc salt and tin salt are dissolved in deionized water according to the molar ratio of 2: 1: 300, and stirring is conducted till the solution is clear; carrying out oil bath reflux at 110-120 DEG C for 3-5 hours, cooling to room temperature, washing and drying to obtain dispersed zinc stannate nanoparticles; the preparation method comprises the following steps: dispersing zinc stannate nanoparticles in 50 mL of isopropanol, magnetically stirring for 24-48 hours, centrifuging for 10-20 minutes at the rotating speed of 8000-10000 rpm, and drying to obtain the double-layer zinc stannate nanosheet. The double-layer zinc stannate nanosheet has larger specific surface area and conductivity, is beneficial to improving the electrochemical performance of the material, has the first charge specific capacity of 680 mAh/g and the first discharge specific capacity of 1347 mAh/g, and has higher discharge specific capacity. The preparation process is relatively simple and easy to operate.

The present invention relates to a negative electrode active material including silicon-based oxide particles and a metal distributed on a surface, inside, or on the surface of and the inside the silicon-based oxide particles, wherein compressive fracture strength measured at a pressure of 100 mN is 170 MPa to 380 MPa, and the silicon-based oxide particles contain Si crystal grains having a crystal grain size of 3 nm to 20 nm.

The invention discloses an inorganic solid electrolyte layer of a lithium battery, a composite negative plate for the lithium battery and a preparation method and application of the composite negative plate. The inorganic solid electrolyte layer comprises inorganic solid electrolyte particles; the inorganic solid electrolyte particles are selected from a lithium-containing material or a mixture of the lithium-containing material and AlPO4; the lithium-containing material comprises a compound consisting of lithium, hydrogen, aluminum, phosphorus, halogen and oxygen elements. The inorganic solid electrolyte used in the invention is high in stability and low in cost, and has certain ionic conductivity, and after the inorganic solid electrolyte is coated on the surface of the negative pole piece to form the composite negative pole piece, the ionic transmission capability on the surface of the negative pole piece and in the negative pole cannot be obviously hindered; and on the basis of not influencing the electrochemical performance, the thermal stability of the negative plate is improved, and the safety of the battery is ensured.

The invention provides a lithium ion battery and a preparation method thereof, and relates to the technical field of lithium ion batteries. Specifically, the lithium ion battery mainly comprises a positive electrode, a negative electrode, electrolyte and a diaphragm, wherein the negative electrode comprises graphite, a silica material and a binder, and the binder comprises an acrylate compound; the electrolyte comprises a cyano compound. According to the invention, the short-circuit safety problem of the silicon-containing negative electrode is solved by adding the olefine acid ester binder, and the olefine acid ester binder has strong binding force on the expansion of the negative electrode, and can well inhibit the thickness increase of the negative electrode piece in the circulation process, thereby reducing the safety risk caused by the expansion of the negative electrode piece; meanwhile, a cyano additive is used in the electrolyte, so that the negative effect caused by an acrylate binder is solved, and the overall circulation and storage safety performance of the battery is greatly improved at the same time.

A lead acid battery is described that makes it possible to suppress an increase in internal resistance and to accurately determine the state of charge or the state of degradation by a method of measuring the internal resistance. The lead acid battery includes an electrode plate group in which a plurality of positive electrode plates having a positive active material containing lead dioxide and a plurality of negative electrode plates having a negative active material containing metallic lead are alternately stacked with separators interposed therebetween. The electrode plate group is immersed in an electrolyte. The flatness of the positive electrode plates after chemical conversion is equal to or less than 4.0 mm

Provided are a negative electrode for a lithium secondary negative electrode battery including: a current collector; a first negative electrode active material layer disposed on the current collector and including a silicon-based active material, a first graphite-based active material, and a linear conductive material; and a second negative electrode active material layer disposed on the first negative electrode active material layer and including a second graphite-based active material. The first graphite-based active material has a carbon coating layer on at least a part of a surface. Also provided is a lithium secondary battery including the negative electrode.

Provided is a lithium secondary battery which includes a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and an electrolyte, wherein the positive electrode includes a lithium composite transition metal oxide powder having a layered structure and a nickel content accounting for 85 atm % or more of total transition metals, and wherein the lithium composite transition metal oxide powder undergoes a 3% or less change in lithium-oxygen (Li—O) interlayer spacing in a state-of-charge (SOC) range of 58% to 72%.

The invention provides a lithium battery negative electrode which is composed of a lithiophilic coating and a current collector, wherein the lithiophilic coating comprises a lithiophilic agent, a lithium layer binding agent, a conductive agent and a binding agent; the lithiophilic agent comprises a metal sulfide, a metal oxide, nano Ni4P5 and nano metal; and the lithium layer binding agent is montmorillonite powder. The surface of the current collector is coated with the lithiophilic coating containing the lithiophilic agent and the lithium layer binding agent to manufacture the lithium battery negative electrode, the technical problem that dead lithium is easily formed in the charging and discharging process of the negative electrode is solved through the synergistic effect of the lithiophilic agent and the lithium layer binding agent, and by adopting the lithium battery negative electrode, the Coulombic efficiency and the reversible capacity of the battery can be effectively improved. The invention also provides a preparation method of the lithium battery negative electrode and a battery containing the negative electrode.

The invention provides a lithium ion battery. The lithium ion battery comprises an electrode assembly and an electrolyte containing fluorosulfonate and/or difluorophosphate substances. The formation gas production area coefficient of the lithium ion battery is alpha, alpha = M * S/200, M is the loading capacity of the negative electrode material on the negative electrode current collector per unit area and ranges from 5mg/cm < 2 > to 100mg/cm < 2 >, S is the specific surface area of the negative electrode material on the negative electrode current collector and ranges from 0.1 m < 2 >/g to 10m < 2 >/g; the exhaust path coefficient of the lithium ion battery is set to be beta, beta is equal to 100/L, L is the width of the coating area of the negative electrode material on the surface of the negative electrode current collector, and L is larger than or equal to 50 mm; and the mass percentage w% of the fluorosulfonate and/or difluorophosphate substances in the electrolyte, alpha and beta meet the condition that w * beta/alpha is more than or equal to 0.01 and less than or equal to 20. The lithium ion battery provided by the invention can give consideration to both high energy density and low formation gas production.

A method for preparing a negative electrode active material for a lithium secondary battery according to one aspect of the present invention comprises the steps of: uniformly mixing silicon and metal oxide; and heating or ball-milling the mixture.

The invention discloses a preparation method of a TiO2-TiNb2O7 composite negative electrode material for a lithium ion battery, and belongs to the technical field of lithium ion batteries. The preparation method comprises the following steps: (1) putting TiO2 fibers into a NaOH solution, and carrying out functionalization treatment on the surfaces of the TiO2 fibers; (2) immersing the TiO2 fiber subjected to surface functionalization treatment into an NbCl5 methanol solution, and depositing Nb (OH) 5 particles on the surface of the TiO2 fiber; and (3) carrying out high-temperature heat treatment on the TiO2 fiber on which the Nb (OH) 5 particles are deposited, so as to obtain the TiO2-TiNb2O7 composite material. According to the method disclosed by the invention, the obtained TiO2-TiNb2O7 composite negative electrode material is of a nanofiber structure, rapid deintercalation of lithium ions is realized, and the material has rapid charging and discharging capability; and the TiO2-TiNb2O7 composite negative electrode material has a self-supporting capability and can be directly used as an electrode when being used in the field of lithium ion batteries, and compared with an existing battery electrode preparation process, foil and electrode coating are omitted, the cost is saved, and the application prospect is wide.

The invention discloses a preparation method of a double-particle-size pitch repeatedly-coated shaped graphite silicon-carbon negative electrode material, which comprises the following steps: performing CVD vapor deposition on nano silicon on shaped graphite, then coating an outer-layer carbon source with a layer of thickness-controllable mesophase carbon through a thermal polycondensation reaction of pitch, and performing double-layer pitch coating, so that better coating can be realized, the nano silicon is prevented from being exposed and being in direct contact with electrolyte, the technical problems in the prior art are thoroughly solved, and the obtained composite silicon-carbon material is high in first efficiency, good in cycle performance and good in rate capability; and according to the mechanism, the silicon carbon material coated with the asphalt with different particle sizes for multiple times is good in coating layer binding property, good in coating effect, uniform, stable and good in conductivity after carbonization, migration of lithium ions is facilitated, the high-rate discharge capacity is improved, and the cycle performance is remarkably improved.

Provided are a negative electrode including a current collector, a first active material layer including first active material particles and disposed on the current collector, and a first pattern and a second pattern alternately disposed separately from each other on the first active material layer, wherein the first pattern includes first pattern active material particles, the second pattern includes second pattern active material particles, a thickness of the first pattern is greater than a thickness of the second pattern, and a volume expansion rate of the second pattern is greater than a volume expansion rate of the first pattern, and a secondary battery including the negative electrode.