75results about How to "High cycle capacity retention" patented technology

The invention relates to a lithium-transition metal compound powder for a positive-electrode material for lithium secondary battery which comprises secondary particles configured of primary particles having two or more compositions and a lithium-transition metal compound having a function of being capable of insertion and release of lithium ions, wherein the powder gives a pore distribution curve having a peak at a pore radium 80 nm or greater but less than 800 nm, and the secondary particles include primary particles of a compound represented by a structural formula including at least one element selected from As, Ge, P, Pb, Sb, Si and Sn, wherein the primary particles of the compound are present at least in an inner part of the secondary particles.

The invention relates to a preparation method of a lithium ion battery carbon microsphere negative electrode material. The method comprises: mixing carbon black, a binder and a solvent to prepare a slurry, conducting spray drying for molding, and then carrying out a high temperature treatment so as to obtain the lithium ion battery carbon microsphere negative electrode material. The lithium ion battery carbon microsphere negative electrode material provided in the invention has a high degree of sphericity and a controllable particle size, so that close packing of the negative electrode material is realized, the volume energy density of electrodes is enhanced. Meanwhile, lithium ions can be embedded from all directions, and the structural stability, the rate capability and the first coulombic efficiency of the material are improved. The carbon microspheres internally have size-controllable gaps, which make up a plurality of ion transport channels, thus being conducive to improving the charge-discharge capacity and cyclic capacity retention rate of the material. Also, the main preparation raw material is carbon black, which has wide sources, no need for breaking, and a low price. And the preparation method has the advantages of simple process, environmental friendliness, low energy consumption and cost, and is easy for large scale production.

The invention discloses a preparation method of vinylidene fluoride polymer of a lithium ion battery electrode material binder, and belongs to the technical field of fluor chemical industry. The preparation method comprises the following steps: 1) adding deionized water, a dispersing agent, a pH modifier, a chain transfer agent, vinylidene fluoride and a second monomer to a polymerization reactor; 2) heating the reactor to 32-52 DEG C, reacting at the reaction pressure of 6.0-9.0MPa and the rotating speed of 800-1600r/min, adding an initiator, and finishing reaction for 4-8 hours, so as to prepare vinylidene fluoride slurry; and 3) degassing, washing and drying the polymer slurry to prepare the product. According to the preparation method of vinylidene fluoride polymer of the lithium ion battery electrode material binder, the vinylidene fluoride polymer with ultra-high molecular weight, small particle size, high purity and high heat-resisting stainability is obtained; and the lithium ion battery prepared by the polymer has the advantages of low binder amount, high peeling strength, high energy density and high circulating capacity retention rate.

The invention discloses a lithium ion battery positive plate capable of supplementing lithium and a lithium ion battery containing this positive plate. This positive pate can provide the lithium source at the first charging, thereby placing the effect of compensating the lithium consumption when the positive and the negative form an SEI film, the first charging/discharging efficiency and the cycle performance are promoted, and the charging capacity and the energy density can be promoted, the lithium ion battery positive plate is especially suitable for the negative system with the low first charging/discharging efficiency, such as: the negative system containing silicon, silicon alloy, silicon oxide, or tin, tin alloy, and tin oxide.

The invention discloses a lithium iron manganese phosphate composite positive electrode material and a preparation method thereof, a lithium battery positive electrode and a lithium battery. The size of the lithium iron manganese phosphate composite positive electrode material is nano-scale, graphdiyne is compounded in a lithium iron manganese phosphate base material, and the mass of the graphdiyne is 0.1-10% that of the lithium iron manganese phosphate base material. The preparation method comprises the steps of dissolving nano-scale lithium source, manganese source, iron source and phosphorus source in a solvent according to the molar ratio of the elements of lithium iron manganese phosphate to form a solution, sequentially adding a complexing agent and a graphdiyne solution into the solution, then drying, grinding, sintering and annealing. Both the lithium battery positive electrode and the lithium battery contain the lithium iron manganese phosphate composite positive electrode material. According to the lithium iron manganese phosphate composite positive electrode material, the migration paths of Li<+> and electrons are shortened by reducing the primary particle size, so that the electric conductivity of the material is improved. According to the preparation method, the performance stability of the lithium iron manganese phosphate composite positive electrode material can be ensured. The discharge gram volume and circulating volume retention rate of the lithium battery is high.

The invention discloses a preparation method of a carbon-coated silicon nanosheet, and the carbon-coated silicon nanosheet. The preparation method of the carbon-coated silicon nanosheet comprises thesteps: 0.1-1 g of a carbon source is added into 5-20 mL of water to be stirred and ultrasonically dispersed for 10-30 min; 0.1-1 g of silicon powder with the D50 particle size being 10-500 nm is addedto be ultrasonically dispersed for 10-30 min; and a hydrothermal reaction is conducted at 100-200 DEG C for 10-24 h, then centrifuging and vacuum drying are carried out, and the carbon-coated siliconnanosheet is obtained. The carbon-coated silicon nanosheet is prepared from a silicon nanosheet and a carbon layer, wherein the periphery of the silicon nanosheet is coated with the carbon layer. Theinvention discloses a silicon-based composite prepared from the carbon-coated silicon nanosheet, and a preparation method of the silicon-based composite. The preparation method of the silicon-based composite comprises the steps: in percentage by mass, 5-12% of the carbon-coated silicon nanosheet, 78-85% of a carbon material and 10% of a carbon source are mixed and ball-milled, the temperature isincreased to be 500-1000 DEG C at 3-10 DEG C/min to carry out calcining for 5-12 h, and the silicon-based composite is obtained. The silicon-based composite is prepared from the carbon-coated siliconnanosheet, the carbon material and a coating carbon layer. The carbon coating layers of the carbon-coated silicon nanosheet and the silicon-based composite buffer volume expansion of silicon, electrical conductivity is enhanced, the double-coating carbon layer of the silicon-based composite further inhibit expansion of the silicon, the first-time charge and discharge efficiency is improved, and the cycle capacity retention ratio is increased.

The purpose of the invention is to present a lithium ion battery cathode material and a preparation method thereof and a lithium ion battery. The cathode material includes a cathode active material, lithium phosphate arranged on at least part of the outer surface of the cathode active material, and a coating layer coating the exposed outer surfaces of the cathode active material and the lithium phosphate and including a conductive polymer. Thus, the residual alkali content on the surface of the cathode active material is low, and the rate performance stability and cyclic capacity retention rate of the cathode material can be improved. The lithium phosphate and the conductive polymer enable the cathode material to have ion-electron conductivity (double conduction), and further improve the rate performance stability and cyclic capacity retention rate of the cathode material. The coating layer can reduce or prevent the side reaction between the cathode active material and the electrolyteand improve the service life of the cathode material.

The invention relates to the field of battery materials and particularly relates to aluminum-doped small particle spherical tricobalt tetroxide and a preparation method thereof. The preparation methodcomprises: mixing a metal solution containing aluminum and cobalt and a precipitant solution according to a volume ratio of 1: 0.8 to 1.5, carrying out multiple crystallization reaction processes at30-60 DEG C to obtain crystals with desired sizes, separating a supernatant liquid and final slurry, and sintering the final slurry in stages to obtain aluminum-doped small particle spherical tricobalt tetroxide. The preparation method has the advantages of simple processes, easy control of the reaction, no pollution in the reaction and easy industrial production. The aluminum-doped small particlespherical tricobalt tetroxide has the advantages of uniform distribution of aluminum, regular surface morphology, good sphericity and high tap density.

The invention discloses a binder and a lithium ion battery containing the same. The binder comprises a cross-linked polymer of which the structural formula is -A-B-C, wherein a chain segment A is provided by a monomer A, a chain segment B is provided by a monomer B, and a chain segment C is at least provided by a monomer C; wherein the monomer A is a polymer monomer endowing low glass transition temperature, the monomer B is a hydrophilic functional monomer, and the monomer C is a crosslinking monomer. The polymer has a low glass transition temperature and forms the binder in combination withan SBR emulsion. When the binder is applied to a silicon-based negative electrode, the cycle performance of the lithium ion battery is obviously improved, so that the cycle life of the lithium ion battery is prolonged.

The invention discloses a lithium metal negative electrode protection method for improving lithium utilization efficiency, and relates to the field of lithium batteries. In the lithium battery, lithium metal is deposited on a current collector to serve as a battery negative electrode, and a high-molecular polymer serves as an additive to be added into an ester electrolyte; the high-molecular polymer is prepared by carrying out polymerization reaction on a monomer A which is acrylonitrile or a derivative thereof, a monomer B which is perfluoroalkyl ethyl methacrylate or a derivative thereof anda monomer C which is alkyl alcohol diacrylate or a derivative thereof. The surface of the lithium metal is negatively charged and -CN and-CF3 in the high-molecular polymer are relatively strong electron withdrawing groups, so that the electrolyte additive is promoted to be preferentially adsorbed on the surface of the lithium metal, and contact between other components in the electrolyte and thelithium metal is reduced; and thus continuous side reaction can be avoided, lithium deposition can be finer and more uniform, generation of lithium dendrites is slowed down, and high lithium utilization efficiency of the lithium metal negative electrode is realized.

The invention discloses a negative plate. The negative plate comprises a current collector, a soft charcoal material layer coated on the outer side of the current collector, and an infiltration conductive coating coated on the outer side of the soft charcoal material layer. A contact angle theta between the infiltration conductive coating and a non-aqueous solvent for lithium ion electrolyte is 45-55 degrees; and the porosity of the infiltration conductive coating is 30%-45%. Further, the negative plate also comprises a bonding conductive coating which is positioned between the outer side of the current collector and the soft charcoal material layer. In addition, the invention also discloses a preparation method of the negative plate and a lithium ion secondary battery using the negative plate. The negative plate improves the rate charging and discharging capacity and cycling capacity retention ratio of the lithium ion secondary battery.

The invention discloses an artificial graphite negative electrode material, a preparation method, application and a battery. The preparation method of the artificial graphite negative electrode material comprises the following steps of (1) carrying out electric demagnetization on graphite fragments with the particle size D50 of 13.5-17.5 microns to obtain a precursor A; (2) the precursor A and a coating agent being modified to obtain a precursor B, and the curing temperature of the coating agent being 80-150 DEG C; and (3) carrying out heat treatment on the precursor B to obtain the artificial graphite negative electrode material. The preparation method of the artificial graphite negative electrode material is simple, short in process time consumption and easy for mass production, the raw materials are common industrial products, and the raw material graphite scraps are low in cost and stable in source; compared with the prior art, the artificial graphite negative electrode material prepared by using the crushed graphite can ensure relatively high tap density, initial efficiency, rate capability and cycle capacity retention ratio, and meets the use requirements of the artificial graphite negative electrode material.

The invention provides a preparation method of a lithium manganate battery. A positive electrode active substance of the lithium manganate battery is spinel lithium manganate, and the molecular formula of the spinel lithium manganate is LiMn2-xMxO4, wherein x ranges from 0.01 to 0.1, M is a doped metal element; and a negative electrode active substance of the lithium manganate battery is a carbon-based material. The preparation method comprises the following steps: sieving the spinel lithium manganate material; respectively pulping the active substances under the screen and the active substances on the screen; coating the surface of a current collector with the obtained pulps in sequence; drying to obtain a positive electrode; putting the positive electrode and a counter electrode lithiumsheet into an electrolyte tank; discharging to a first preset voltage; taking out the positive electrode; assembling the positive electrode and a negative electrode clamping diaphragm into a batterycell; putting the battery cell into a shell, and carrying out injection molding to obtain the lithium manganate battery. The battery obtained by the preparation method disclosed by the invention is high in energy density, good in cycle performance and high in capacity retention ratio.

The invention provides an electrolyte and a secondary battery. The electrolyte comprises an electrolyte salt, an organic solvent and additives, wherein the additives comprise a benzene single nitrilecompound, cyclic sulfate and fluoroethylene carbonate. When the electrolyte disclosed in the invention is applied to the secondary battery, the anti-overcharging performance of the secondary battery can be obviously improved; and meanwhile, the secondary battery also has relatively low cycle impedance and relatively high cycle capacity retention ratio.

The invention relates to the technical field related to lithium ion batteries, and particularly provides a lithium ion battery electrode containing a micro-nano graphene coated single crystal positiveelectrode material. Raw materials comprise the micro-nano graphene coated single crystal positive electrode material, a conductive agent, a binder and a current collector, wherein the preparation rawmaterials of the micro-nano graphene coated single crystal positive electrode material include graphene and a single-crystal positive electrode material, and the single-crystal positive electrode material is a layered single-crystal structure. The invention provides the lithium ion battery electrode containing the micro-nano graphene coated single crystal positive electrode material. Crystal forms and particle size distribution of the single crystal positive electrode material before and after coating are basically consistent, and when the micro-nano graphene coated positive electrode material meeting the conditions is used as the preparation raw material of the battery electrode, comprehensive performance of the battery is favorably optimized.

A lithium-ion secondary battery includes at least a negative electrode, a positive electrode, and an electrolyte solution. The negative electrode includes at least negative electrode active material particles. Each of the negative electrode active material particles contains at least a SiO_x particle and a Si layer. The Si layer covers a surface of the SiO_x particle. The Si layer has a thickness not smaller than 10 nm and not greater than 100 nm. The electrolyte solution contains at least one selected from the group consisting of FEC and VC.

The invention provides a cyclic phosphamido lithium salt, and the structural formula is as shown in formula I in the specification, wherein R1-R8 are independently selected from one of a hydrogen atom, a halogen atom, an alkyl group, a halogenated alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, an electron withdrawing group and a heteroatom-containing heterocyclic group. The invention also provides an electrolyte additive, an electrolyte, a preparation method of the cyclic phosphamido lithium salt and a battery. The cyclic phosphamido lithium salt provided by the invention has relatively high stability when being applied to an electrolyte, and an SEI film formed in a charge-discharge cycle process is more beneficial to the passing of lithium ions, so that the electrical property of a battery can be improved.