19results about How to "Improve initial Coulombic efficiency" patented technology

The invention belongs to the technical field of sodium-ion battery negative electrode materials, and particularly relates to a biomass-based closed-pore hard carbon material, a preparation method thereof and a sodium-ion battery negative electrode material. According to the invention, biomass is subjected to preheating treatment and is converted into a hard carbon precursor with carbonization capability; the hard carbon precursor has a firm structural frame in structure and contains abundant ultra-micropores. And performing Joule heat treatment on the hard carbon precursor, and performing instantaneous high-temperature carbonization to quickly generate the biomass-based closed-pore hard carbon material with adjustable closed pores, carbon interlayer spacing and defect structures. The biomass-based closed-pore hard carbon material prepared by adopting the method disclosed by the invention has the advantages that the storage performance on sodium ions is remarkably improved, and the initial coulombic efficiency and the reversible capacity are high. The method is easy and convenient to operate, raw materials are easy to obtain, the biomass-based closed-pore hard carbon material is rich in closed pores and moderate in interlayer spacing, the defects of the prior art in the aspects of preparation and performance are overcome, and the biomass-based closed-pore hard carbon material has wide application prospects in the field of energy storage.

The invention discloses preparation of a polycyclic aromatic hydrocarbon-based pre-sodium modification agent and application of the pre-sodium modification agent in a hard carbon negative electrode, and belongs to the technical field of negative electrodes of sodium-ion batteries. The chemical property of polycyclic aromatic hydrocarbon is adjusted by virtue of induction and conjugation effects, and the pre-sodium-modification agent with controllable chemical reaction rate is prepared and applied to the hard carbon negative electrode. Firstly, in an ether-based solvent, polycyclic aromatic hydrocarbon molecules are selected to be grafted with functional groups with different electronegativity to serve as electron acceptors, the electron acceptors and metal sodium are subjected to free radical reaction, and a pre-sodium agent is obtained and used for efficient pre-sodium. By selectively adjusting the reducibility of the pre-sodium modification agent and assisting the generation of a high-stability interface film, the damage to the internal structure of the negative electrode and the excessive sodium modification are avoided. According to the preparation process, the pre-sodium modification agent can be obtained only through one-step stirring, and the electrode is soaked to achieve pre-sodium modification. The method has the advantages of simplified steps, simple equipment and good repeatability, and is suitable for large-scale production.

The invention discloses a high-entropy positive electrode material of a potassium ion battery and a preparation method and application of the high-entropy positive electrode material, the high-entropy positive electrode material is a layered oxide with a P2 / rock salt biphase symbiotic structure, the chemical general formula of the high-entropy positive electrode material is K < 0.6 > Mn < 0.75-x > Ni < 0.1 > Ti < 0.1 > Mg < x > Cu < 0.05 > O2, and x is more than 0 and less than or equal to 0.1. A high-temperature solid-phase method is adopted in the preparation process, the high-entropy layered oxide positive electrode material with symbiotic two phase structures of P2 and rock salt is finally formed by regulating and controlling the types and the content of doped elements, sliding of a TM layer in the charging process and large structural stress generated in the circulating process are relieved through introduction of a small amount of rock salt phase, and the performance of the positive electrode material is improved. And lattice distortion and cracks in particles in the long circulation process are improved, so that the electrochemical circulation stability and rate capability of the potassium ion battery are remarkably improved.

The invention discloses a sodium ion positive plate and a preparation method thereof, a sodium ion capacitor and a sodium ion battery. The sodium ion positive plate comprises a capacity compensation agent, porous carbon, a sodium ion positive electrode material, a conductive agent, a binder and an auxiliary agent, wherein the capacity compensation agent comprises a positive lithium supplement agent with a first mass percent, and the positive lithium supplement agent is used for reducing the potential of the negative plate containing hard carbon and compensating the irreversible capacity of the negative plate; the index requirements of the positive electrode lithium supplementing agent are as follows: the specific capacity is greater than or equal to 420mAh / g, and the first coulombic efficiency is less than or equal to According to the technical scheme, the high-power characteristic of the sodium ion positive plate is improved, the irreversible capacity of the negative electrode is compensated, the initial coulombic efficiency, the energy density and the cycle life of the sodium ion battery or the capacitor are effectively improved, and the preparation cost of the sodium ion battery or the capacitor is reduced.

This invention relates to the field of battery technology, specifically to a composite negative electrode current collector, its preparation method, and its application. The composite negative electrode current collector of this invention includes a polymer material layer, a lithium replenishment layer, and a conductive metal layer. The lithium replenishment layer is located on at least one surface of the polymer material layer, and the conductive metal layer is located on the surface of the lithium replenishment layer away from the polymer material layer. The lithium replenishment layer includes a composite lithium material comprising a lithium metal core and a lithium compound coating layer covering the surface of the lithium metal core. The conductive metal layer has multiple through-hole structures. The composite negative electrode current collector of this invention, through the coordination of its various layer structures, is beneficial for improving the storage performance of the negative electrode, reducing battery impedance, shortening the electrolyte wetting time, enhancing lithium replenishment capacity, preventing the formation of lithium dendrites, and improving battery safety performance.

The invention belongs to the technical field of sodium ion battery negative electrode materials, and discloses a soy sauce residue-based hard carbon negative electrode material, a preparation method and an application of the soy sauce residue-based hard carbon negative electrode material in a sodium ion battery. The method comprises the steps of pre-oxidation, inorganic acid washing, organic solvent cleaning and high-temperature carbonization, the core technology idea of pre-oxidation driven synergistic purification is initiated, the core technology idea is organically combined with the subsequent high-temperature carbonization process, the pretreatment bottleneck of industrialization of preparation of hard carbon from soy sauce residues is overcome, and the method is suitable for industrial production. The high-grease soy sauce residues are efficiently and economically purified through pre-oxidation, and a primary barrier is cleared for preparing hard carbon by utilizing the soy sauce residues on a large scale; the precise reconstruction of the microstructure of the hard carbon material is synchronously realized, and the obtained hard carbon material has high reversible specific capacity and good initial coulombic efficiency; a high-performance product can be obtained at a relatively low carbonization temperature due to the pure precursor, so that the energy consumption and the production cost are reduced. The invention provides a scheme for preparing the sodium ion battery hard carbon negative electrode with low cost and high performance.

The invention belongs to the technical field of battery materials, and discloses a structure-reinforced silicon-based electrode for a lithium battery and a preparation method and application of the structure-reinforced silicon-based electrode for the lithium battery. Pores in a powder electrode are uniformly filled with organic / inorganic hybrid buffer connectors in situ through an in-situ polymerization strategy; the connector can be tightly connected with a current collector, an active material, a binder, a conductive agent and other components in a powder electrode, an electrode structure with a stable structure is constructed, abundant artificial SEI layers are formed on the surfaces of electrode silicon particles, and the mechanical stability of the electrode structure is remarkably improved. When the silicon-based electrode is used as a negative electrode, the prepared lithium ion battery shows high initial coulombic efficiency (ICE) of 85.1% and excellent cycle performance (after 300 cycles under 1.0 A / g, the specific capacity is higher than 2000 mAh / g, and the capacity retention rate is larger than 80%).

The invention provides a preparation method of a hard carbon material and application of the hard carbon material in a sodium-ion battery. The preparation method comprises the following steps: uniformly mixing soft carbon precursor powder with carboxylic acid dienophile, carrying out Diels-Alder reaction in a reaction kettle to obtain a carboxylated soft carbon precursor, and carrying out high-temperature carbonization to obtain the hard carbon material. The thermal conversion process of the soft carbon precursor is adjusted and the crosslinking degree of the soft carbon precursor is enhanced by introducing carboxyl, so that rearrangement of adjacent graphite microcrystal fragments is effectively prevented, and the hard carbon material with rich closed-cell structures and expanded interlayer spacing is formed; in addition, the surface of the hard carbon material is coated with a carbon shell, so that surface defects of the hard carbon material are effectively reduced. The obtained hard carbon material is used as a sodium-ion battery negative electrode, shows excellent reversible sodium storage specific capacity and initial coulombic efficiency, and realizes high value-added utilization of petroleum coke. The carbon precursor adopted by the method is wide in source, low in cost and easy to obtain, the preparation process is simple, convenient, safe and reliable, the cost is controllable, and the method is suitable for large-scale production and practical application.

The present disclosure relates to a sulfide-based solid electrolyte having a novel composition and a novel crystal structure.

The invention discloses a secondary battery and electric equipment, and belongs to the technical field of new energy. According to the application, the positive electrode active material layer comprises a double-layer structure, and the conductive agent in the first active material layer close to the positive electrode current collector is controlled to be the fibrous conductive agent, and the conductive agent in the second active material layer far away from the positive electrode current collector is controlled to be the granular conductive agent, so that electrolyte can be promoted to permeate in the positive electrode material; polarization in the charging and discharging process is reduced, and the initial coulombic efficiency, the cycle performance and other electrochemical performance of the secondary battery are better.

The present application provides a carbon material, a preparation method therefor and the use thereof, a negative electrode plate, a secondary battery, and a power consuming device. The carbon material comprises a porous carbon substrate and an amorphous carbon layer provided on at least part of a surface of the porous carbon substrate. When the carbon material is used as a negative electrode active material, it can make full use of the abundant porous structures in the porous carbon substrate for lithium / sodium precipitation or lithium / sodium intercalation and avoid the side reactions due to the contact between the abundant active sites on the surface of the porous carbon substrate and an electrolyte solution, such that the initial coulombic efficiency and the actual capacity of a secondary battery can be improved.

The invention discloses a carbon-coated tin nanoparticle, a preparation method thereof and a lithium ion battery material thereof, and relates to the field of battery materials, the preparation method comprises the following steps: dissolving bacillus subtilis spores in deionized water, and adding glucose for activation culture to obtain supernate; adding SnCl4, and incubating to obtain a suspension liquid; adding a complexing agent, carrying out ultrasonic treatment, and centrifuging to remove a complex, so as to obtain centrifugate; centrifugally collecting precipitates; dissolving the precipitate in deionized water, and carrying out ultrasonic oscillation to obtain a solution; the method comprises the following steps: dissolving a carbon nanotube or graphene oxide in a solvent to obtain a carbon nanotube solution or a graphene oxide solution; mixing the solution with the carbon nanotube solution to obtain a mixed solution; freezing and drying; and placing the powder in a protective gas atmosphere for high-temperature annealing to obtain the product. The method has the beneficial effects that voids in the bacterial carbon shell relieve volume expansion of tin particles in lithiation and lithium removal processes, and the carbon nanotubes uniformly integrated in the bacterial carbon shell serve as efficient electron conduction channels to disperse anisotropic stress.

This invention relates to the field of sodium-ion battery technology, specifically to a modified hard carbon material and its preparation method, a negative electrode sheet, and a sodium-ion battery. The modified hard carbon material is obtained by mixing and grinding a hard carbon precursor with naphthalene at a mass ratio of 5-9:1-5, followed by a two-stage heat treatment. This invention utilizes the gas-phase infiltration and high-temperature carbonization of naphthalene at specific temperatures. In the first stage, naphthalene is converted into gaseous molecules. Its small kinetic diameter allows it to penetrate deep into the micropores of the hard carbon precursor and be adsorbed under capillary action and pressure difference. In the second stage, naphthalene undergoes pyrolysis, transforming in situ into an amorphous soft carbon layer. This achieves uniform and deep filling of carbon within the micropores of the hard carbon, effectively reducing the average pore size. This not only promotes the pre-desolvation of solvated sodium ions but also helps to obtain an ultrathin and stable NaF-rich solid electrolyte interface film, improving the rate performance of the material. Furthermore, this process is simple, efficient, and low-cost, which is beneficial for large-scale production.

The invention provides a modified silicon-based negative electrode material and a preparation method and application thereof, the modified silicon-based negative electrode material comprises a silicon-based core, and a cationic functional layer, a transition carbon layer and a conductive agent network layer which sequentially coat the surface of the silicon-based core, and the transition carbon layer is generated on the surface of the cationic functional layer in situ. The modified silicon-based negative electrode material is of a core-shell structure, the shell is distributed in multiple layers, the layers influence one another and have a synergistic effect, and the electrochemical performance of the silicon-based negative electrode material can be obviously improved.

The invention discloses an amorphous iron-based silicon-phosphorus composite negative electrode material and a preparation method and application thereof, the raw materials of the iron-based silicon-phosphorus composite negative electrode material comprise an iron element, a silicon element, a phosphorus element and a carbon material, the molar ratio of the silicon element to the phosphorus element is 2: 1-1: 2, the molar ratio of the silicon element to the iron element is 8: 1-1: 2, and the mass ratio of an iron / silicon / phosphorus mixture to the carbon material is 5: 5-8: 2; the iron-based silicon phosphorus composite negative electrode material is prepared by a one-step or multi-step mechanical ball milling method. In the iron-based silicon phosphorus composite negative electrode material, the introduction of the iron elementary substance induces the microstructure to be disordered and reduces the lithium ion diffusion energy barrier, and meanwhile, the iron elementary substance and the lithium phosphide formed in situ respectively provide abundant electron and ion transmission paths and cooperatively buffer the huge volume deformation of the silicon negative electrode in the lithiation / delithiation process; furthermore, the electrochemical reversibility, the cycling stability and the rate capability of the material in the lithium storage process are effectively improved.

The present application provides a silicon oxygen material, a negative electrode material, and its preparation method, and a lithium ion battery. The silicon oxygen material includes a silicon oxide having a chemical formula SiOx, where 0<x<2, wherein the silicon oxygen material is primary particles having a Wadell sphericity greater than 0.92. The negative electrode material provided by the present disclosure includes the silicon oxide having a high sphericity, the silicon oxide has a more stable structure during a cycling process, so that it is capable of avoiding the problem of cracking of particles of the material due to repeated generation of the SEI film, thereby improving cycling performance of the material and reducing the volume expansion due to SEI film generation.

The invention relates to the technical field of batteries, in particular to a composite negative electrode current collector and a preparation method and application thereof. The composite negative electrode current collector comprises a high polymer material layer, a lithium supplementing layer and a conductive metal layer, the lithium supplementing layer is located on the surface of at least one side of the high polymer material layer, and the conductive metal layer is located on the surface, away from the high polymer material layer, of the lithium supplementing layer; the lithium supplementing layer comprises a composite lithium material, and the composite lithium material comprises a lithium metal core and a lithium compound coating layer coating the surface of the lithium metal core; the conductive metal layer is provided with a plurality of through hole structures. According to the composite negative electrode current collector disclosed by the invention, through the matching of each layer structure, the storage performance of a negative electrode plate is improved, the battery impedance is reduced, the infiltration time of an electrolyte is shortened, the lithium supplementing capability is improved, lithium dendrites are prevented from being generated, and the safety performance of the battery is improved.

The invention provides a pre-lithiation binder as well as a preparation method and application thereof. The pre-lithiation binder comprises the following raw materials: natural polysaccharide, epichlorohydrin and lithium salt. The silicon-based negative electrode binder for the lithium ion battery is a three-dimensional network polymer formed by crosslinking natural polysaccharide, epichlorohydrin and lithium salt, the binder has good binding performance due to the complex network structure, and the integrity of a negative electrode structure can be kept; meanwhile, by introducing the lithium salt, the initial coulombic efficiency of the silicon-based negative electrode can be effectively improved, the lithium ion loss of the positive electrode can be reduced, and the high energy density of the silicon-based material can be developed, so that the energy density of the lithium ion battery can be further improved.

The present invention relates to an all-solid-state battery having an anode layer comprising a solid electrolyte and a metal organic framework; a solid electrolyte layer disposed on the anode layer; and a cathode layer disposed on the solid electrolyte layer. The all-solid-state battery may also include a lithium layer interposed between the anode layer and the solid electrolyte layer.