23results about How to "Improve long-term cycle stability" patented technology

The invention relates to an aqueous alkaline zinc-iodine battery and a preparation method thereof, and belongs to the technical field of aqueous zinc-iodine batteries. The battery includes: a positive electrode; a negative electrode; and an aqueous alkaline electrolyte; wherein the positive electrode comprises a current collector, a positive electrode active material, a conductive agent and an adhesive, and the positive electrode active material is iodide; the aqueous alkaline electrolyte comprises a chlorine-containing additive, a zinc salt electrolyte, an alkaline inorganic salt and water. The aqueous alkaline zinc-iodine battery provided by the invention is low in cost and simple to manufacture. According to the aqueous alkaline zinc-iodine battery provided by the invention, the iodide is adopted as the positive electrode active material, so that instability and potential safety hazards caused by taking an iodine elementary substance as the positive electrode at present are avoided. The battery disclosed by the invention releases a high-potential discharge platform at 1.65-1.68 V, the discharge capacity reaches 372-385 mAh.g <-1 >, and the battery shows rapid oxidation-reduction kinetics and excellent long-acting cycle stability.

The invention relates to a titanium carbide thin film material, a preparation method and a zinc ion hybrid capacitor, and the preparation method of the titanium carbide thin film material comprises the following steps: mixing titanium carbide nanosheets with an aqueous solution of ammonium salt, carrying out ultrasonic treatment, carrying out solid-liquid separation, and taking the supernatant liquid to obtain an intercalated titanium carbide nano colloid; adding a water-soluble salt into the intercalated titanium carbide nano colloid, reacting, carrying out solid-liquid separation, washing with water, and drying to obtain titanium carbide aerogel; and carrying out compression molding on the titanium carbide aerogel to obtain the titanium carbide film material. The super-wrinkled titanium carbide film prepared through a nanosheet distortion strategy has obviously improved compression resistance. Under the pressure of 1MPa, the microstructure of the electrode material does not change. In addition, the titanium carbide thin film material has lower tortuosity and can be directly used for constructing an electrode, ion transmission can be accelerated, the dynamic performance of the electrode is remarkably improved, and the requirement for high-quality load application is met.

The invention provides a modified lithium-rich manganese-based positive electrode material as well as a preparation method and application thereof, and the preparation method of the modified lithium-rich manganese-based positive electrode material comprises the following steps: dipping the lithium-rich manganese-based positive electrode material by using a fluorocarbon surfactant, and performing high-temperature annealing to obtain the modified lithium-rich manganese-based positive electrode material, the modified lithium-rich manganese-based positive electrode material is prepared by the preparation method of the modified lithium-rich manganese-based positive electrode material, and is applied to the field of lithium ion batteries. Compared with the prior art, the modified lithium-rich manganese-based positive electrode material has the advantages that the relatively high theoretical specific capacity of the lithium-rich manganese-based positive electrode material is reserved, the surface stability of the material is improved through fluorine doping of crystal lattices on the surface of the material, and the modified lithium-rich manganese-based positive electrode material which is excellent in rate capability and more stable in long-term cycle performance and is applied to the field of lithium ion batteries is formed; the preparation method is simple in process and high in operability.

The present application discloses a lithium-ion battery and an electronic device, and relates to the technical field of lithium-ion batteries. The lithium-ion battery comprises a negative electrode plate, and the negative electrode plate comprises a silicon-carbon material, wherein the silicon-carbon material contains a hydrogen element, and the mass percentage of the hydrogen element is a% based on the mass of the silicon-carbon material. The present application controls the content of the hydrogen element in the silicon-carbon material within a suitable range, thereby reducing the side reaction between the silicon-carbon material and the electrolyte, and improving the long-term cycle stability of the lithium-ion battery.

The invention discloses a graphene-nickel oxide composite material prepared on the basis of a one-step hydrothermal method and application of the graphene-nickel oxide composite material in preparation of a lithium ion battery, NiO is integrated into a graphene nanostructure, so that a unique thin nanosheet array with a porous conductive channel is generated, and meanwhile, in the composite material, the graphene-nickel oxide composite material has good electrochemical performance. NiO generates controllable aggregation and re-accumulation, which can buffer electrode stress and improve conductivity, graphene is also beneficial to insertion of lithium ions compared with common graphite, and the added graphene not only improves the conductivity, but also can be used as a flexible substrate of NiO to prevent NiO particles from diffusing into electrolyte in the circulation process. In addition, due to the unique layered hollow structure of NiO, the electrode stress can be reduced by controlling the volume change, and the electrochemical reaction kinetics is greatly improved. The cycling stability and the capacity of the lithium ion battery are effectively improved.

The invention relates to the technical field of lithium ion batteries, and discloses a high-nickel ternary positive electrode material and a preparation method and application thereof, and the preparation method comprises the following steps: mixing and sintering a nickel-cobalt-manganese precursor, a lithium source, niobium salt and fused salt. According to the preparation method of the high-nickel ternary positive electrode material provided by the invention, the niobium salt and the molten salt form a liquid phase environment at a relatively low temperature, and the niobium element can efficiently enter a crystal lattice, so that uniform bulk phase doping in a real sense is realized, and the electrochemical stability and the thermal stability are improved; meanwhile, the niobium doping can ensure the rapid and uniform transmission of the lithium source, so that the lithiation is more sufficient, and the lithium-nickel mixed arrangement caused by lithium deficiency is reduced in dynamics.

The invention provides a high-crystallinity hollow positive electrode precursor and a preparation method and application thereof. The method comprises the following steps: a ternary transition metal mixed salt solution, a precipitant solution and a complexing agent solution are introduced into a base solution in a parallel flow manner, a co-precipitation reaction is performed, feeding is stopped when particles subjected to the co-precipitation reaction grow to target particle sizes, and the high-crystallinity hollow positive electrode precursor is obtained, wherein the co-precipitation reaction comprises a nucleation stage and a growth stage, the feeding speed of a precipitant solution in the nucleation stage is smaller than the feeding speed of the precipitant solution in the growth stage, and the feeding speed of the precipitant solution in the co-precipitation reaction is smaller than 10 L / h. The ternary positive electrode material prepared from the high-crystallinity hollow positive electrode precursor provided by the invention has high capacity and also has good structural stability and cycling stability.

This invention relates to a lithium-ion battery and an electrical device. The positive electrode active material layer of the lithium-ion battery includes a first coating and a second coating sequentially disposed outwards along the surface of the positive electrode current collector. The first coating comprises lithium iron phosphate, and the second coating comprises lithium manganese iron phosphate. The melting point T of the positive electrode current collector is... m The ratio of the particle size Dv50 of the first coating to the particle size of the negative electrode material is denoted as A, the thickness of the first coating is denoted as B, and the particle size Dn50 of the lithium manganese iron phosphate in the second coating is denoted as C, ranging from 1.2 to 7.7 μm. 3 / ℃. In the lithium-ion battery provided by this invention, a double-layer coating technology is used to improve the positive electrode sheet. A first coating containing lithium iron phosphate is set on the side close to the surface of the positive electrode current collector, giving full play to its advantages of high safety and low risk of fire and explosion; a second coating containing lithium manganese iron phosphate is set on the side away from the positive electrode current collector, which can ensure the energy density of the battery and coordinate the value of the coating to achieve synergistic optimization of safety and energy density.

This invention discloses a method for preparing a surface-modified oxide solid electrolyte, comprising the following steps: S1: reacting an oxide solid electrolyte matrix with a bifunctional ionic liquid modifying compound in the presence of a catalyst under an inert atmosphere to obtain an intermediate of a surface-grafted ionic liquid monomer; S2: subjecting the intermediate obtained in step S1 to a free radical copolymerization reaction with an ethylene glycol divinyl ether monomer in the presence of an initiator, thereby in-situ copolymerizing the grafted ionic liquid monomer and the ethylene glycol divinyl ether monomer to form a polymer coating layer, thus obtaining the surface-modified oxide solid electrolyte. The preparation method of this invention not only eliminates interfacial side reactions through chemical bonding between the ionic liquid modifying compound and residual alkali / hydroxyl groups on the electrolyte surface, but also forms a polyionic liquid / polyether composite coating layer through in-situ copolymerization, possessing both high ionic conductivity and flexible segment characteristics, significantly reducing interfacial impedance and inhibiting lithium dendrite growth.

The application provides an organic lithium-iodine battery based on a two-electron transfer mechanism and a manufacturing method and application thereof. The organic lithium-iodine battery comprises a positive electrode, a negative electrode and an organic electrolyte. The positive electrode active material used by the positive electrode comprises iodide and / or bromide, and the organic electrolyte comprises an organic solvent containing a chlorine-containing additive. The organic lithium-iodine battery uses iodide as the positive electrode active material, thereby avoiding the instability and safety hazards existing in the current I2 positive electrode. The organic solvent containing the chlorine-containing additive is used as the organic electrolyte, and excellent electrochemical performance is provided through a two-electron conversion mode. Compared with a traditional lithium-iodine battery, the organic lithium-iodine battery has higher capacity, energy density and higher output voltage. In addition, the organic lithium-iodine battery has excellent low-temperature insensitivity. At-25 DEG C, the battery realizes 2500 cycles at the cost of 20% capacity decay, and can still work stably at a low temperature of-30 DEG C.

The application relates to the technical field of lithium ion battery materials, and specifically discloses a modified lithium titanium aluminum phosphate material, a preparation method and application thereof. The material comprises a lithium titanium aluminum phosphate material with a chemical formula of Li 1+X Al X Ti 2‑X (PO4)3, wherein the x satisfies 0.3 <= x <= 0.5, the modified lithium titanium aluminum phosphate material is prepared by preparing a lithium titanium aluminum phosphate matrix from a mixture containing a lithium source, an aluminum source, a titanium source, a phosphorus source and an organic reaction medium, and then treating the lithium titanium aluminum phosphate matrix in a sulfur dioxide-containing atmosphere; and the organic reaction medium contains a salicylic acid derivative and a nitrogen-containing compound. The method combines the process of organic reaction medium-assisted gas phase transmission and controllable sintering in a sulfur dioxide atmosphere, effectively solves the problems of uneven element distribution and large grain boundary resistance, and the modified lithium titanium aluminum phosphate material can be used in lithium ion batteries to significantly improve the rate performance and cycle stability of the batteries.

The invention relates to a solid electrolyte based on a bead type MOF-808 network and a preparation method of the solid electrolyte. The preparation method comprises the following steps: immersing an ultrathin fiber membrane prepared by an electrostatic spinning technology into an MOF-808 precursor solution, transferring into a reaction kettle, and preparing the MOF-808-coated PAN composite fiber membrane under high-temperature and high-pressure reaction conditions. Performing hot pressing on the composite fiber membrane under a certain pressure to obtain a bead type MOF-808 crystal loaded three-dimensional fiber network; and finally, casting a PEO polymer matrix to the composite fiber membrane in a layered manner to obtain the solid polymer electrolyte. According to the invention, polyacrylonitrile fiber is taken as a carrier under high temperature and high pressure conditions, and MOF-808 crystals with regular octahedron structures are loaded on the surface of the fiber in a beaded form, so that lithium ions infiltrated in the crystals can be transmitted along a continuous fiber path; and the large screening aperture of the fully exposed MOF-808 crystal ensures the high diffusivity of lithium ions, and the application of the metal organic framework material in polymer electrolyte is optimized, so that the long-term cycling stability of the solid-state lithium battery is improved.

The invention discloses a lignin polyaniline composite binder, preparation thereof and application of the lignin polyaniline composite binder in a hard carbon negative electrode of a sodium-ion battery. The method comprises the following steps: firstly, performing carboxymethylation modification on lignin to obtain carboxymethyl lignin; then, polyhydric alcohol serves as a cross-linking agent, a covalent bond is formed through dehydration condensation of hydroxyl on a molecular chain of the polyhydric alcohol and carboxyl of the carboxymethyl lignin, meanwhile, the polyhydric alcohol, the conductive polyaniline and the carboxyl of the carboxymethyl lignin are subjected to cross-linking compounding through the hydrogen-bond interaction between the hydroxyl of the polyhydric alcohol and amino on a molecular chain of the conductive polyaniline, and the lignin polyaniline composite binder is constructed. According to the composite binder, the compatibility of a hard carbon negative electrode and an ester or ether electrolyte is improved, and the structural integrity of the electrode and a stable SEI film can be effectively maintained in the circulation process, so that the first effect, the circulation stability and the rate capability are remarkably improved.

The invention discloses a sodium ion battery and a formation method thereof, and the formation method is as follows: the sodium ion battery to be formed stands under the conditions that the temperature is 60-92 DEG C and the pressure is 0.2-0.3 MPa, and the negative electrode of the battery comprises a sodium-rich state potassium titanyl phosphate carbon composite material; and under the conditions that the temperature is 40-60 DEG C and the pressure is 0.3-0.5 MPa, charging is carried out with 0.02-0.2 C multiplying power current until the upper limit of the activation voltage is reached, and then discharging is carried out until the lower limit of the activation voltage is reached. According to the invention, a sodium-titanium-rich potassium titanyl phosphate carbon composite material is used as a negative electrode, and sodium ions are added into a negative electrode active material, so that consumption of Na ions in an electrolyte due to K-Na ion exchange in an early charging and discharging process of potassium titanyl phosphate is reduced, and the concentration of the sodium ions in the electrolyte is kept unchanged; and a specific formation charge-discharge system is arranged in a matched manner, so that the exchange of K ions and Na ions in the electrolyte is further inhibited, and the coulombic efficiency of the first charge-discharge is ensured to be higher than 90%.

The invention discloses a manufacturing method of a novel solid electrolyte interface layer. The manufacturing method comprises the following steps: S1, compounding lithium perchlorate, lithium bis (oxalato) borate and an organic solvent into a mixed solution; s2, adding a certain amount of fluoroethylene carbonate or tris (2, 2, 2-trifluoroethyl) phosphoric acid, and continuously stirring uniformly to form a liquid electrolyte; s3, taking the conductive base material as a substrate, and depositing a cathode electrochromic material; s4, liquid electrolyte is used, the cathode electrochromic material is used as a working electrode, and after the cathode electrochromic material circularly works for not less than 10 circles under a specific voltage window, a solid electrolyte interface layer which is not less than 20 nm thick and rich in LiF is formed on the surface of the cathode electrochromic material in an in-situ growth mode. The prepared novel solid electrolyte interface layer has excellent electrochemical stability and cycling stability, effectively improves the performance of an electrochromic device, prolongs the service life of the electrochromic device, reduces the production cost, and has important application value and market prospect.

The application provides a supercapacitor carbon and a preparation method thereof. The preparation method comprises the following steps: firstly, mixing petroleum coke and pitch uniformly to obtain a first material; then, carbonizing the first material under the condition of an oxygen-containing gas to obtain a second material; then, crushing the second material and mixing the second material with alkali to perform primary activation under an inert atmosphere to obtain a third material; then, washing and drying the third material, mixing the third material with pitch and alkali, and performing secondary activation under an inert atmosphere; finally, washing and drying to obtain the supercapacitor carbon. The supercapacitor carbon has mesopore-micropore two-stage pore channels, wherein the mesopore has a pore diameter of 2nm-5nm, and the micropore has a pore diameter of 0.4nm-2nm. The application realizes the short-range through-hole pore channel structure design of the petroleum-based porous material through a combined process, provides a large specific surface area for the formation of an effective double electric layer, guarantees the rapid transmission of electric charges, and significantly improves the long-period cycle stability of the material.

The present invention discloses a method for synthesizing Pt single atoms and clusters loaded inside nitrogen-doped porous carbon, comprising: S1, obtaining Pt nanoparticles by a chemical solution method; S2, synthesizing Pt / UiO-66-NH2 by in-situ growth using a solvent thermal method; S3, sintering Pt / UiO-66-NH2 at a high temperature to obtain Pt SA ‑Pt C / NDPCM. According to the present invention, by in-situ growing Pt nanoparticles inside UiO‑66‑NH2 and performing high-temperature sintering, a nitrogen-doped porous carbon material with single-atom and cluster loading is obtained, and the electrocatalytic hydrogen production is promoted, while its stability is improved, and the cost of the catalyst is further reduced.

A functional fiber diaphragm, a preparation method thereof and an application thereof in a polymer solid-state lithium battery, which relates to a fiber diaphragm and a preparation method and application thereof. It aims to solve the problems of poor rate performance, low capacity and short cycle life of polymer solid-state lithium batteries. The functional fiber diaphragm is formed by electrostatic spinning and thermal micro-crosslinking of a polymer / inorganic salt mixed solution dispersed with electronic conductor nanorod fillers. Preparation method: electrostatic spinning and calcining a mixed solution of metal salt and polymer powder to obtain an electronic conductor nanorod powder; then electrostatic spinning and thermal micro-crosslinking of the mixed solution with a polymer and an inorganic salt to obtain a functional fiber diaphragm; applying a polymer electrolyte precursor liquid on the fiber diaphragm and then polymerizing and curing to obtain a solid polymer electrolyte; assembling a positive electrode, a functional fiber diaphragm and a negative electrode into a solid-state lithium battery, the capacity retention rate of the battery after 800 cycles at room temperature is 76.1% to 82.3%, and can be used in the field of lithium batteries.

This invention relates to the field of electrochemical energy storage materials and lithium metal battery technology, specifically to an in-situ polymerized solid electrolyte, its preparation method and application, and lithium metal batteries. This in-situ polymerized solid electrolyte is prepared by heating a ring-opening polymerization reaction using 1,3-dioxolane and 1,1,1-trifluoro-2,3-epoxypropane as reactants, sodium thiosulfate as an initiator, and lithium salt and plasticizer fluoroethylene carbonate as a precursor solution. This electrolyte possesses numerous amorphous regions, which is beneficial for ion transport, enabling the formation of a self-supporting dense structure. It also ensures close contact with the electrode, resulting in a pure interface that effectively reduces interfacial impedance and avoids side reactions at the electrode interface. Furthermore, it enhances oxidation resistance, broadens the electrochemical window, and inhibits dendrite growth. While achieving good mechanical properties, it also improves the cycle stability and safety performance of the battery. It has excellent application prospects in lithium metal batteries, lithium-ion batteries, solid-state energy storage systems, or flexible electronic devices.

The present application relates to the technical field of magnesium foil material, in particular to a vacuum evaporation magnesium film, a preparation method and application thereof, the magnesium film comprises a substrate and a thin film layer, the material of the thin film layer is magnesium and is covered on the surface of the substrate by vacuum evaporation; the preparation method uses aluminum foil, copper foil, gold foil, silver foil, nickel foil, molybdenum foil, titanium foil, tin foil, stainless steel foil, polymer composite metal foil, metal alloy foil, carbon-coated metal foil, polyimide and high polymer material as the substrate, a layer of high-purity magnesium thin film is uniformly deposited on the surface of the substrate by controlling the vacuum evaporation process; when the magnesium film is applied to a magnesium battery, the substrate provides good electrical conductivity and mechanical support, and the magnesium layer directly participates in the electrochemical reaction as an active material, which not only improves the energy density and cycle life of the magnesium battery, but also simplifies the manufacturing process and reduces the cost; the magnesium negative electrode prepared by the method has excellent electrochemical performance and stability, and has good application prospect.

The invention discloses a carbon felt electrode for an all-vanadium redox flow battery as well as a preparation process and application of the carbon felt electrode, and relates to the field of redox flow batteries. The preparation process of the carbon felt electrode for the all-vanadium redox flow battery comprises the following steps: immersing a carbon felt into a urea solution, adding a mixed solution of a bismuth source, polyvinylpyrrolidone and a nitric acid aqueous solution, reacting at a first temperature, cooling, taking out and washing to obtain a carbon felt loaded with a bismuth composite layer; and immersing the carbon felt loaded with the bismuth composite layer into a mixed solution formed by a transition metal source and an organic ligand, reacting at a second temperature, cooling, taking out, washing, performing suction filtration and drying to obtain the carbon felt electrode. Through two heating reactions, a bismuth composite layer is formed on the carbon felt, and a Co-MOF skeleton structure or a Fe-MOF skeleton structure is formed on the bismuth composite layer through in-situ growth, so that the active sites and hydrophilicity of the carbon felt electrode are improved, and the electrochemical performance of the battery is effectively improved.

The invention relates to a method for preparing a thin-layer carbon-coated positive electrode material by adopting a liquid-phase organic carbon source, which comprises the following steps of: introducing a liquid-phase organic matter serving as a carbon source into a positive electrode active material system such as lithium iron phosphate, forming an adsorption or interface modification structure on the surface of a positive electrode material particle by the carbon source, performing solid-liquid separation, and performing in-situ carbonization under a protective atmosphere to obtain the thin-layer carbon-coated positive electrode material. And constructing a continuous thin-layer carbon coating structure on the surfaces of the positive electrode material particles to obtain the thin-layer carbon coated positive electrode material. The method is simplified in process, convenient to operate, low in cost and suitable for large-scale preparation; the obtained material is good in carbon layer continuity and high in interface stability, and is beneficial to improvement of electronic conductivity and reduction of electrode polarization, so that the rate capability and the cycle stability are improved, meanwhile, the particle surface structure stability can be improved, transition metal dissolution is inhibited in the cycle process, and the long-term cycle stability of an electrode is improved. The method is suitable for various lithium ion battery positive electrode material systems, and is especially suitable for lithium ion batteries with relatively high requirements on rate capability and cycle life.

This invention discloses a hydrogen sensing thin film and a room temperature sensor, belonging to the field of semiconductor gas-sensitive materials and sensor technology. The hydrogen sensing thin film is composed of tungsten oxide (WO3) and highly dispersed Pt-Pd-Ni-Co-Cu-Fe hexa-element high-entropy nano-alloy particles. The sensor includes a SiO2 / Si substrate, interdigitated electrodes disposed on the substrate, and a sensitive thin film covering the surfaces of the electrodes and the substrate. The fabrication method of this invention employs a three-target synergistic magnetron sputtering process, utilizing a high-power pulsed magnetron sputtering (HiPIMS) power supply to drive a pure W target and a strongly magnetic Fe-Co-Ni alloy target respectively, while simultaneously using a DC power supply to drive a non-magnetic Pt-Pd-Cu alloy target. By effectively controlling the oxygen content within the thin film through oxygen flow rate regulation and reactive magnetron sputtering, and based on the phase formation process driven by differences in oxyphilic behavior and high mixing entropy, the phase type and size distribution within the film are controlled to form a controllable tungsten oxide + nano-high-entropy alloy dual-phase structure. Furthermore, a gradient coupling interface with oxygen-rich vacancies and strong metal-support interactions is constructed between the two phases, significantly reducing the potential barrier for hydrogen atom spillover. This hydrogen sensing thin film achieves high sensitivity operation at room temperature, shortened response time, and exhibits excellent resistance to CO poisoning and long-term cycling stability.