12results about How to "Improve first-time efficiency" patented technology

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.

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 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 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 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.