21results about How to "Improve first-time efficiency" patented technology

The invention discloses a fast-charging low-temperature graphite composite material, a preparation method and application thereof, the composite material is of a core-shell structure, the core is porous graphite and a carbon nanotube doped with the porous graphite, and the shell is composed of a lithium supplement agent and a lithium sulfonate complex of the lithium supplement agent. The preparation method comprises the following steps: soaking porous graphite in a conductive polymer solution, adding a catalyst, a cross-linking agent and an oxidizing agent, carrying out oxidative polymerization and carbonization to obtain catalyst-doped porous graphite, and introducing carbon source gas through a vapor deposition method to obtain carbon nanotube-doped porous graphite; and adding the obtained material into a lithium sulfonate solution, adding a lithium supplement agent, uniformly mixing, and carrying out spray drying to obtain the graphite composite material. According to the obtained material, the electronic conductivity of the material is improved by using the carbon nanotubes grown on the inner core, and the lithium sulfonate coated on the outer shell has relatively strong solvation capability, so that the transmission rate of lithium ions is improved, and the rate capability is improved; meanwhile, the lithium supplement agent releases lithium ions in the charging and discharging process, the first efficiency is improved, and the low-temperature and fast-charging performance is improved.

The invention discloses a lithium-doped silicon-carbon composite material, a preparation method and application, and belongs to the technical field of preparation of lithium ion battery negative electrode materials. According to the lithium-doped silicon-carbon composite material disclosed by the invention, metal lithium is doped in porous carbon, and nano silicon is deposited on the surface of the porous carbon, so that the resistivity of the composite material is reduced; the rate capability of the lithium ion battery is improved; the surface of the nanometer silicon is coated with carbon twice through passivation gas and carbon source gas, so that the defects of the surface of the nanometer silicon are reduced, and the nanometer silicon is prevented from being in direct contact with an electrolyte, thereby reducing the side reaction of a negative electrode interface of the lithium ion battery, reducing the decomposition of the electrolyte, reducing the gas production and improving the first efficiency.

The invention discloses a preparation method of a hard carbon sodium battery negative electrode material, and relates to a preparation method of a negative electrode material. The method comprises the following steps: 1, pre-oxidation treatment; 2, preparing an asphalt / binder mixture; 3, heat treatment; 4, rough grinding; 5, carbonizing; and 6, crushing. Asphalt which is low in cost and stable in supply is used as a raw material, surface oxygen-containing functional groups are enhanced through surface oxidation, then resin is added to serve as a binder to enable the asphalt to form a cross-linked structure, a large number of irregular closed-pore structures exist in a generated hard carbon structure through high-temperature carbonization, the sodium storage performance of the material is improved, meanwhile, the specific surface area is reduced, and the specific surface area is increased. Therefore, side reactions are reduced, the first efficiency is improved, and the high-performance sodium battery negative electrode material with the reversible capacity higher than 300mAh / g and the first efficiency higher than 90% is obtained. The hard carbon sodium battery negative electrode material can be obtained.

The invention provides a silicon-based negative electrode material which comprises a silicon-based inner core and a coating layer coating the silicon-based inner core, the coating layer is made of a carbon material and a fast ion conductor, and the mass content of the fast ion conductor in the coating layer is gradually increased in the direction from the silicon-based inner core to the coating layer. The silicon-based negative electrode material is excellent in ionic conductivity and electronic conductivity, stable in structure and beneficial to being used in a negative electrode. The invention also provides a preparation method of the silicon-based negative electrode material, a negative electrode, a battery and electric equipment.

The application discloses a preparation method of a nitrogen-containing heterocyclic compound and an alkali metal salt of the nitrogen-containing heterocyclic compound, and steps of the preparation method of the nitrogen-containing heterocyclic compound comprise: (1) uniformly mixing trithiocyanic acid with a first solvent, introducing sulfuryl fluoride gas or adding an alkenyl sulfonyl fluoride to perform a reaction, and obtaining a crude product through a crude treatment after the reaction is finished; (2) purifying the crude product to obtain the nitrogen-containing heterocyclic compound shown in a structural formula 1; wherein R1, R2 and R3 are each independently selected from -H, -SO2F or -CH2-(CH2) n -SO2F, n is an integer selected from 1-10, and R1, R2 and R3 are not H at the same time. The preparation method of the nitrogen-containing heterocyclic compound and the alkali metal salt of the nitrogen-containing heterocyclic compound can be applied to a large amount of trithiocyanic acid in a lithium battery electrolyte, raw materials are easy to obtain, operation is simple, the yield is high, the condition is mild, the requirement for equipment is low, and the method is suitable for industrial production.

The invention relates to the technical field of batteries, in particular to a composite negative electrode material as well as a preparation method and application thereof. The composite negative electrode material comprises an inner core matrix and a composite layer arranged on at least part of the surface of the inner core matrix, the inner core matrix comprises graphite; the composite layer comprises a complex of porous titanium oxide, a conductive carbon material and a lithium phenyl sulfonate compound. According to the composite negative electrode material, through coating of the composite layer, the cycle performance and the rate capability of the composite negative electrode material can be improved, and the composite negative electrode material is good in fast charging performance and high in safety performance.

This invention discloses a mesoporous carbon composite material and its preparation method. The preparation method is as follows: S1: Using tetraethyl orthosilicate as the silicon source, an ethanol / deionized water mixture, a surfactant as the solvent system, and a conductive agent as the dopant, a polycondensation reaction is carried out under acid-base catalysis. A silica / soft template composite is formed through a sol-gel process, followed by high-temperature sintering to obtain a silica composite template; S2: A mixed solution A is prepared by mixing a phenol source, a dispersant, and water; a mixed solution B is prepared by mixing an aldehyde source, a lithium supplement, and a catalyst; S3: Mixed solutions A, B, and the silica composite template are reacted, carbonized, and activated. The resulting material is then added to a hydrofluoric acid solution to dissolve the template, and the resulting material undergoes thermal reduction to obtain the mesoporous carbon composite material. The mesoporous carbon prepared using the template method exhibits advantages such as high uniformity, large pore volume, and low powder resistivity. It can be applied to silicon-carbon composite materials to increase the deposition amount of nano-silicon, improve specific capacity, and reduce the expansion of silicon-carbon materials.

The invention discloses a preparation method of a pre-lithiation silicon-based composite material, a pre-lithiation silicon-based composite material and an application thereof. A Li2CO3-coated lithium rod is used as a working electrode and a mixed solvent is used as a solvent. A silicon-based composite material is deposited on the surface of the working electrode by an electrochemical deposition method. The silicon-based composite material is subjected to high-temperature carbonization sintering to obtain the pre-lithiation silicon-based composite material. The mixed solvent comprises a silicon-based precursor material and a polymer monomer which are respectively and evenly dispersed in an ionic liquid. The invention has the advantages of high silicon deposition density, controllable and stable process, fast time, high lithium replenishment consistency, etc. The pre-lithiation of the silicon-based material is achieved by a core metal lithium rod. The obtained silicon-based composite material has the characteristics of high initial efficiency, low expansion, etc. Compared with the traditional chemical polymerization method, impurities caused by oxidants are avoided and the reaction efficiency is high.

The invention belongs to the technical field of batteries, and particularly relates to a battery cell and a formation method thereof, an energy storage device and a power utilization device. The battery cell formation method comprises the following steps: executing multi-stage charging formation operation at a preset temperature: charging a to-be-charged battery cell with a first charging current until the to-be-charged battery cell increases a first charge state; charging with the second charging current to the Nth charging current in sequence until the state of charge reaches the target state of charge; the first charging current to the Nth charging current are gradually increased in sequence, and at least one of the second charging current to the Nth charging current is not less than 0.5 C. The formation time of the battery is obviously shortened, the production efficiency is improved, and the manufacturing cost is reduced; meanwhile, through the stepped current design and the temperature and pressure synergistic effect, the technical problems that electrolyte infiltration in a large-size battery cell is uneven and gas is difficult to discharge can be effectively solved, a more uniform and compact SEI film is formed, the consistency of the battery cell is improved, the cycle life of the battery cell is prolonged, and the safety performance of the battery cell is improved.

This invention discloses a method for preparing SnCo-doped hard carbon composite material and its application in sodium-ion batteries. The preparation method involves adding an organotin compound to an organic solvent, followed by the addition of a graphene oxide solution. The sodium salt compound is then uniformly dispersed, and a porous tin / graphene compound is prepared through hydrothermal reaction and freeze-drying. This compound is then ground and mixed uniformly with cobalt powder and sintered at 600-1000℃ to obtain a tin-cobalt / graphene composite. This composite is then added to a starch solution, uniformly dispersed, and spray-dried. The mixture is then sintered at 500-800℃ for 1-6 hours under an inert atmosphere, followed by a further increase in temperature to 1000-1800℃ for 1-10 hours to obtain the SnCo-doped hard carbon composite material. The resulting material exhibits excellent power performance and high specific capacity in sodium-ion batteries.

This invention relates to the field of battery technology, specifically to a composite anode material, its preparation method, and its applications. A composite anode material includes a carbon material matrix and a coating layer disposed on the surface of the carbon material matrix. The coating layer contains amorphous carbon and a dual-conductor composite. The dual-conductor composite has a core-shell structure, with the core layer containing a carbon-based conductive agent and the shell layer containing a fast-ion conductor. The composite anode material of this invention, through the synergy of the various layers, can further improve the fast-charging performance of the anode material and enhance the battery's capacity and cycle performance.

The application discloses a silicon-carbon negative electrode material, a preparation method, application and a battery. The preparation method of the silicon-carbon negative electrode material comprises the following steps: performing methane gas phase carbon coating on a silicon source to obtain the silicon-carbon negative electrode material; wherein, when the methane gas phase carbon coating is performed, the vacuum degree of the system is 300-5000 Pa; and the mass-volume ratio of the silicon source and methane is 1 kg:(10-150) L. The uniformity and coverage of the coating layer on the surface of the silicon source of the silicon-carbon negative electrode material are better, the carbon deposition layer has a special surface structure, the volume change of the negative electrode material in the charging and discharging process can be buffered, and the negative electrode material can realize better electrochemical performance.

The application relates to the technical field of secondary battery material preparation, and discloses a preparation method of a resin-based coated pitch-based hard carbon composite material, which comprises the following steps: S1, uniformly mixing pitch, sodium nitrite, 1,4-p-phenylenediamine and a catalyst, performing a diazotization reaction, and obtaining aminated pitch; S2, uniformly mixing the aminated pitch and an aldehyde solution, adding a graphene oxide solution and a nitrogen source, uniformly mixing again, adding a phenol solution, performing an oxidation-reduction reaction, forming a heteroatom-doped resin-based hard carbon composite shell outside the aminated pitch-based hard carbon, and obtaining a hard carbon precursor material; and S3, carbonizing the hard carbon precursor material to obtain a hard carbon composite material. Through the technical scheme, the problem that the first discharge specific capacity, the compaction density and the fast-charging performance of the hard carbon material cannot be balanced in the prior art is solved, so that the comprehensive performance of the hard carbon material is improved.

The invention discloses a preparation method and application of amorphous silicon and a lithium ion battery. The preparation method of the amorphous silicon comprises the following steps: S1, adding silane gas and a straight-chain saturated hydrocarbon solvent into a reactor according to a certain volume ratio; s2, heating and pressurizing the reactor to enable the reactor to reach a supercritical state; and S3, after keeping the supercritical state for a certain time, collecting to obtain the amorphous silicon. According to the method, the amorphous silicon is prepared by thermally decomposing the silane in a supercritical state, so that a high-efficiency and low-energy-consumption preparation technology is realized.

The invention relates to a dry-method electrode composite binder, a preparation method thereof, a negative plate and a lithium ion battery in the technical field of lithium battery production. The composite binder is formed by mixing high-swelling styrene-acrylic emulsion and high-molecular-weight PTFE emulsion. The swelling of the high-swelling styrene-acrylic emulsion is greater than or equal to 100%, and the molecular weight of the high-molecular PTFE emulsion is not less than 500W. According to the invention, the high-swelling styrene-acrylic emulsion and the PTFE emulsion are precipitated into the composite binder in a mixed co-precipitation form, the high-swelling styrene-acrylic in the composite material can improve certain wettability for the system, and the swelled styrene-acrylic may cover part of PTFE, so that the PTFE reaction sites are reduced, and the service life of the system is prolonged. And PTFE is prevented from reacting with Li and e-electrons to lose part of active lithium in the first-circle negative electrode lithium embedding process, and the first-time efficiency is improved, so that the battery has more stable performance and longer service life in subsequent circulation.

The application belongs to the technical field of lithium ion battery materials, and particularly relates to a kind of heteroatom doped pitch-based hard carbon composite material and a preparation method thereof, the preparation raw materials of the heteroatom doped pitch-based hard carbon composite material include the following components by weight fraction: 90-100 parts of pitch, 1-10 parts of crosslinking agent, 1-5 parts of heteroatomic compound, 1000-2000 parts of organic solvent, 1-10 parts of coupling agent, 5-20 parts of organic metal compound. The application uses lithium-containing heteroatomic compound to reduce the irreversible capacity loss inside the material, and at the same time, by matching pitch, crosslinking agent, coupling agent and the like, the electronic conductivity, tap density, first efficiency and other properties of the pitch-based hard carbon can be improved.

The invention provides a lithium-rich manganese-based positive electrode material as well as a preparation method and application thereof, and relates to the technical field of lithium ion batteries. In the lithium-rich manganese-based positive electrode material, Mg and P elements are uniformly distributed from a bulk phase to the surface, W element is uniformly distributed in the bulk phase, the surface is in gradient distribution with gradually increased concentration, the content of W in the bulk phase is a, and the average content of the surface is b, 0% lt; a is less than or equal to 0.6 mol%, alt; and b < = 2mol%. According to the invention, through synergistic doping of multiple elements on the body surface, the cycling stability and the voltage drop of the positive electrode material, especially the high-temperature cycling performance, can be remarkably improved, and meanwhile, the specific discharge capacity and the first efficiency of the lithium ion battery are also remarkably improved.

The application discloses a kind of anti-expansion silicon-based negative pole and preparation method thereof, from inside to outside including foil, lithium supplement layer attached to both sides of foil, silicon-based active material layer attached to the outside of lithium supplement layer, amorphous carbon layer attached to the outside of silicon-based active material layer and the graphite layer of outermost side;The foil is porous foil, and the hole of porous foil is filled by lithium supplement layer;The thickness of amorphous carbon layer is 20-100 μm, and the area density of amorphous layer is 0.2-5 times of the area density of silicon-based negative pole coating.

The application discloses a preparation method of a carbon composite material doped with multiple metal elements. The preparation process comprises the following steps: S1, dispersing a porous carbon precursor, organic lithium fluoride, an organic rare earth compound and an organic catalyst in a solvent, drying after hydrothermal reaction, and obtaining the porous carbon precursor loaded with lithium / rare earth elements / catalysts; S2, uniformly mixing the obtained material with an activating agent and a doping agent, and activating at a temperature of 900-1100 DEG C to obtain the porous carbon doped with multiple metal elements; and S3, performing reduction treatment and surface passivation treatment on the porous carbon doped with multiple metal elements to obtain the porous carbon composite material doped with multiple metal elements. The obtained material utilizes lithium doping and rare earth doping porous carbon to improve the electronic conductivity of the material and the interlayer spacing of the carbon material, utilizes the catalyst to grow carbon nanotubes to improve the conductivity of the material and reduce the expansion, and through reduction and passivation treatment, the activity of the surface of the material is reduced, and the initial efficiency is improved.

The present invention discloses a graphite composite material and a preparation method thereof, a negative electrode active material, a secondary battery and an electric device. The graphite composite material comprises a core and a coating layer located on the surface of the core; wherein the material of the core comprises graphite, and the material of the coating layer comprises a nitrogen-doped porous aluminum oxide-carbon composite material. The graphite composite material provided by the present invention improves the first efficiency of the graphite material and improves the rate performance of the battery.

The high-nickel, low-cobalt cathode material provided in this application includes a cathode material substrate, a first coating layer, and a second coating layer. The first coating layer coats the surface of the cathode material substrate, and the second coating layer coats the surface of the first coating layer. The first coating layer comprises a material with the chemical formula Li. a Ni b Co c M 1‑b‑c O d The material comprises M, which includes one or both of Mn and Al, with 0.2 ≤ a ≤ 1, 0.88 < b ≤ 0.98, 0 ≤ c < 0.06, b + c < 1, and 1.6 ≤ d ≤ 2; the material of the second coating layer includes one or more of Li3PO4, Li2SO4, and LiPO3. The above-mentioned high-nickel, low-cobalt cathode material can prevent the electrolyte from corroding the cathode material matrix, protect the integrity of the bulk structure, and effectively inhibit the decomposition and collapse of the layered structure of the high-nickel, low-cobalt cathode material during charge-discharge cycles, thereby improving the long-cycle performance of the high-nickel, low-cobalt cathode material.