10415 results about "Electrolyte" patented technology

The invention discloses a refined disassembly system and method for a battery monomer, and belongs to the technical field of battery disassembly. The production line comprises a perforating device, a cutting device, a cutting device, a scattering device, a sorting device, a color sorting device, a defluorination device and a powder removal device. The method comprises the following steps: perforating a battery to discharge electrolyte, separating a shell from an inner core by a cutting device, cutting the inner core by a cutting device, scattering by a scattering device, sorting a diaphragm by a sorting device, sorting positive and negative electrode materials by a color sorting device, and respectively removing fluorine by a defluorination device. And finally, the metal foil and the powder are separated through the powder removing device, the damage degree of the crystal structure of the black powder can be reduced, the black powder and the metal fragments are efficiently separated according to the density difference, the metal foil and the black powder are not likely to be excessively mixed, the separation purity is high, the secondary treatment situation is reduced, efficient separation and recycling of the electrode material are achieved, and the production cost is reduced. And the comprehensive function and the resource utilization rate of the system are obviously improved.

The invention discloses an anti-fouling piezoelectric ceramic membrane which comprises a support body, a coil and a piezoelectric ceramic separation layer, the support body is made of porous ceramic with a through hole in the middle; the coil is a closed loop composed of a lead coil and a crystal oscillator; the piezoelectric separation layer is coated on the inner wall of the through hole of the support body; and the coil is arranged between the support body and the piezoelectric ceramic separation layer. When a medium containing electrolyte passes through a membrane hole, the coil generates induction direct current, the direct current is converted into positive wave pulse current through the oscillator, the wound and overlapped piezoelectric ceramic membrane separation layer is excited, ultrasonic vibration is generated, and therefore the membrane dirt blocking condition is reduced, the use efficiency of the ceramic membrane is improved, and the maintenance and use cost is reduced.

The invention relates to a flexible aqueous binder for a lithium battery negative electrode and a preparation method thereof. The preparation method comprises the following steps: firstly, preparing a flexible polyurethane prepolymer containing vinyl by taking hydroxyl-terminated polybutadiene, isocyanate and hydroxyl acrylate as main raw materials; vinyl-containing compounds such as water-soluble acrylic acid (salt) or acrylamide, oil-soluble acrylic ester or acrylonitrile and the like are used as monomers and are combined with a flexible polyurethane prepolymer to prepare the negative water-based binder with flexible cross-linking points through free radical polymerization. The aqueous binder prepared by the technical method provided by the invention can realize point-to-point and point-to-line bonding modes with a pole piece active substance on a microstructure, so that the bonding strength of the active layer material and a copper foil is improved on the premise of not influencing the electrolyte resistance of the binder; and the flexibility of the negative pole piece and the subsequent processing stability are obviously improved.

The invention provides an electrolyte for a negative-electrode-free sodium metal battery, a preparation method of the electrolyte and the negative-electrode-free sodium metal battery, and relates to the technical field of sodium ion batteries. The electrolyte is mainly prepared from sodium salt and a weak coordination organic solvent, wherein the concentration of the sodium salt in the electrolyte is 1-2.5 mol / L. According to the electrolyte, through the weak coordination organic solvent and specific sodium salt concentration selection in the electrolyte, more anions can enter the solvation structure of the electrolyte to form the electrolyte with the anion-atmosphere solvation structure, and it is verified that the electrolyte has the advantages that the electrolyte is simple in structure and convenient to use. The electrolyte for the negative-electrode-free sodium metal battery can effectively relieve the problem that an existing high-voltage negative-electrode-free sodium metal battery is short in cycle life.

A positive electrode material of the present disclosure includes: a positive electrode active material; and a first solid electrolyte material coating at least partially a surface of the positive electrode active material, wherein the first solid electrolyte material includes Li, Ti, M1, and F, and the M1 is at least one element selected from the group consisting of Ca, Mg, Al, Y, and Zr.

The invention belongs to the technical field of halide solid-state electrolyte, and relates to a high-conductivity and high-lithium-stability modified halide solid-state electrolyte material constructed by solid source plasma, and a preparation method and application of the high-conductivity and high-lithium-stability modified halide solid-state electrolyte material. According to the preparation method, a halide solid electrolyte is taken as a matrix, halogenated ammonium salt is taken as a solid source, and the halide solid electrolyte is subjected to synergistic doping modification of elements such as nitrogen, fluorine / chlorine / bromine and the like by utilizing a plasma technology, so that the modified halide solid electrolyte material is obtained. The modified halide solid electrolyte material shows excellent conductivity and lithium-lithium symmetrical battery performance, and has a wide market application prospect. Meanwhile, the preparation method provided by the invention is simple, rapid, efficient and convenient, is easy to control, and contributes to promoting the development and application of the high-performance halide solid electrolyte material.

In order to solve the problem of insufficient electrolyte infiltration in the middle position of a pole piece of a winding type long and narrow battery in the prior art, the utility model provides a diaphragm and a lithium ion battery, the diaphragm comprises a base membrane layer and a PVDF (Polyvinylidene Fluoride) coating layer, the PVDF coating layer is arranged on the surface of the base membrane layer and comprises a first area and two second areas, and the first area and the second area are arranged on the surface of the base membrane layer. The first area is arranged in the middle of the diaphragm, the two second areas extend from the edge of the first area to the end part of the diaphragm in the length direction, and the porosity of the first area is greater than that of the second areas. According to the diaphragm provided by the utility model, the second region with small porosity is relatively high in overall density, so that the rigidity and the tensile resistance of the diaphragm are improved, that is, through the combination of the first region and the second region, the overall wettability of the diaphragm can be improved, and the mechanical strength of the diaphragm can be ensured; the electrochemical performance and the service life of the lithium ion battery are improved.

The invention discloses an insulating tape for a new energy battery and a preparation method of the insulating tape, and relates to the technical field of new energy battery assemblies. The insulating tape for the new energy battery is prepared by coating pretreated glass fiber cloth with a coating, the coating is prepared from the following raw materials in parts by weight: 15 to 20 parts of modified polyimide resin, 2 to 4 parts of epoxy resin E-51, 71 to 77 parts of an ethanol / butanone mixed solvent, 3 to 5 parts of modified nano silicon dioxide, 0.2 to 0.4 part of a silane coupling agent KH-550, 0.1 to 0.3 part of polydimethylsiloxane, 0.1 to 0.2 part of paraffin-based mineral oil and 0.3 to 0.5 part of triethylene tetramine. The glass fiber cloth pretreatment material comprises deionized water and a 5%-8% sodium hydroxide solution. The insulating adhesive tape for the new energy battery contains the modified polyimide resin, so that the high temperature resistance and electrolyte resistance of the adhesive tape can be enhanced, the insulativity is improved, and the modified nano silicon dioxide is good in dispersity. The preparation process is fine, the glass fiber cloth is fully pretreated, the preparation process is standard, and the use requirements of new energy batteries can be met.

A nanocomposite electrode and a supercapacitor device including said nanocomposite electrode. The nanocomposite electrode includes a mixture of at least one binding compound, at least one conductive additive, and at least one molybdenum doped carbon material coated onto a substrate. The supercapacitor device includes two nanocomposite electrodes disposed facing one another, wherein the substrate of each nanocomposite electrode is coated with the mixture on an inside facing surface and the outer surfaces of the nanocomposite electrodes are not coated with the mixture, and the inside facing surfaces are separated by at least one electrolyte.

The invention discloses a method for preparing a multi-carbon product through acid electrocatalysis carbon dioxide reduction and belongs to the field of chemistry and chemical engineering. An electro-catalysis carbon dioxide reduction system takes a Cu-based catalyst modified by HEDP as an electrode material, and K < + > in an electrolyte can be effectively enriched on the surface of the Cu-based catalyst due to the complexing effect of HEDP on K < + >, so that the local pH is increased, C-C coupling is promoted, and efficient conversion of CO2 to a multi-carbon product under an acidic condition is realized. According to the invention, HEDP molecules with a K < + > complexing function are introduced into the surface of a Cu-based catalyst for the first time, and the Cu-based catalyst is applied to an acidic electrocatalytic carbon dioxide reduction system with low K < + > concentration. The preparation method of the electrocatalytic system cathode catalyst is simple, mild in reaction condition and simple to operate, can effectively relieve the problem of carbonate deposition in an alkaline electrocatalytic system, and has industrial application prospects.

The invention relates to the technical field of gas sensors, and particularly discloses an electrochemical formaldehyde sensor electrode, a preparation method thereof and an electrochemical formaldehyde sensor. The electrochemical formaldehyde sensor comprises an electrochemical formaldehyde sensor electrode and a binary electrolyte, the electrochemical formaldehyde sensor electrode comprises a polytetrafluoroethylene film, the polytetrafluoroethylene film is coated with slurry for an electrochemical formaldehyde sensor electrode; and the slurry is formed by mixing nano manganese dioxide, platinum carbon and a Nafion solution. According to the electrochemical formaldehyde sensor, the electrode prepared from the slurry formed by mixing the nano manganese dioxide, the platinum carbon and the Nafion solution has relatively high catalytic activity, so that the sensor shows extremely high sensitivity and extremely good linearity on formaldehyde, and the electrochemical formaldehyde sensor has relatively high catalytic activity by regulating and controlling the proportion of the binary electrolyte. The electrochemical formaldehyde sensor has the advantages of high sensitivity, low cost, fast response, high detection precision and the like.

The invention discloses an electrochemical pressure sensor based on polyelectrolyte gel and a preparation method thereof, and belongs to the technical field of pressure-sensitive elements and pressure sensors. The electrochemical pressure sensor comprises a polyelectrolyte gel pressure sensitive layer, a positive electrode and a negative electrode, wherein the surface of the polyelectrolyte gel pressure sensitive layer is provided with a bowl-shaped groove array structure; the positive electrode is positioned on the upper surface of the pressure sensitive layer; the negative electrode is positioned on the lower surface of the pressure sensitive layer; the polyelectrolyte gel pressure sensitive layer comprises PVA, LiCl and PSS. The surface bowl-shaped groove array structure prepared by using the nucleation effect has excellent pressure-sensitive performance: on one hand, the sensitivity of contact between polyelectrolyte gel and an electrode to pressure is improved, so that the sensor realizes excellent pressure response characteristic; and on the other hand, the surface microstructure gel electrolyte preparation method with less damage to the mold and wider applicability is realized. The electrochemical pressure sensor provided by the invention has the characteristics of high response rate and high output power, and has important value for development of high-performance self-energized pressure sensors.

The invention relates to the technical field of supercapacitors, in particular to an alkali-activated solid-waste-based supercapacitor and a preparation method thereof.The preparation method comprises the steps that industrial solid waste and fiber forestry and agricultural residues are subjected to co-pyrolysis to form organic-inorganic composite solid waste gelling powder, an alkali activator and a functional additive are added to prepare alkali-activated slurry, and the alkali-activated slurry is prepared; pouring, molding and curing to obtain an alkali-activated solid waste-based electrolyte substrate; the method comprises the following steps: performing high-temperature pyrolysis, activation and the like on granular agricultural and forestry wastes to prepare a carbon-based composite conductive material, and preparing a biochar electrode plate; the preparation method comprises the following steps: taking PVDF as a raw material, bonding and curing the PVDF and the raw material, immersing the PVDF and the raw material into a KOH solution containing a PVA thickener, inserting a glass fiber diaphragm, and regulating and controlling the use amount of PVDF and other binders and a solvent system to optimize slurry viscosity and film forming uniformity so as to obtain an electrode film with mechanical flexibility and interface adhesive force; the composite electrode forms a stable composite interface in the process of being in contact with an alkali-activated electrolyte interface, and the phenomena of interface aging and capacitance attenuation caused by mismatching between the electrode and the electrolyte in a traditional cement-based system are effectively avoided.

The invention relates to the technical field of batteries, in particular to a gel electrolyte prepolymerization solution, a lithium battery and a preparation method of the lithium battery. The gel electrolyte prepolymerization liquid comprises the following components: an electrolyte which accounts for 70%-99% of the total mass of the gel electrolyte prepolymerization liquid; the cross-linking monomer accounts for 1%-10% of the total mass of the gel electrolyte prepolymerization liquid; an initiator accounting for 0.3-5% of the total mass of the crosslinking monomer; the fluorocarbon surfactant accounts for 0.01%-5% of the total mass of the gel electrolyte prepolymerization liquid, the fluorocarbon surfactant comprises a perfluoroalkyl chain CnF2n + 1, and n is larger than or equal to 6. According to the invention, the fluorocarbon surfactant is introduced into the gel electrolyte pre-polymerization liquid, so that the electrode / electrolyte interface composition and structure are improved, the wettability is improved, the interface stability is improved, the loss of the electrolyte is inhibited, the accumulation of by-products of the positive electrode under high voltage and in the circulation of the negative electrode is reduced, and the cycle life and the stability of the battery are remarkably improved.

The invention relates to the technical field of polymer electrolyte, in particular to a self-repairing type gel polymer electrolyte membrane, a preparation method and application in an energy storage battery, the self-repairing type gel polymer electrolyte membrane is prepared by the following steps: dissolving amino-terminated polyethylene glycol in an organic solvent, adding trimesic acid under the protection of an inert atmosphere, heating, stirring and reacting to form a pre-polymerized solution, cooling, and then adding trimesic acid into the pre-polymerized solution to prepare a self-repairing type gel polymer electrolyte membrane; the preparation method comprises the following steps: adding glyoxylic acid and glacial acetic acid, carrying out a constant temperature reaction to obtain a solution A, adding LiTFSI into the solution A, carrying out ultrasonic dispersion to a homogeneous phase, pouring the obtained slurry onto a template, and carrying out a drying curing reaction to obtain the self-repairing gel polymer electrolyte membrane. A rigid aromatic cross-linking agent is used for inhibiting polymer crystallization and improving mechanical integrity, an imine bond-based dynamic covalent network is introduced to realize an autonomous interface repairing function at the working temperature of the battery, and meanwhile, a polyethylene glycol ether oxygen chain is used for constructing an efficient lithium ion transmission channel; therefore, the technical boundary that the conductivity, the mechanical strength and the interface stability of the traditional GPE are difficult to collaboratively optimize is broken through.

The invention relates to the technical field of food fresh-keeping materials, in particular to a chitosan-curcumin nano-composite fresh-keeping agent and a preparation method thereof.The chitosan-curcumin nano-composite fresh-keeping agent comprises nano-particles of a chitosan-sodium alginate-oxidized sodium alginate interpenetrating network structure, according to the nanoparticles, protonated amino groups of chitosan and carboxyl groups of sodium alginate form a polyelectrolyte compound core, aldehyde groups of oxidized sodium alginate and amino groups of chitosan are subjected to a Schiff base reaction to form a chemical cross-linked network, and zinc ions, amino groups of chitosan, carboxyl groups of sodium alginate and carboxyl groups of oxidized sodium alginate form coordination cross-linking; curcumin and epigallocatechin gallate form a compound through a hydrogen bond and a hydrophobic effect, the compound is embedded in an interpenetrating network structure, beta-diketone groups of curcumin and zinc ions form chelating coordination, a chitosan-sodium alginate-oxidized sodium alginate ternary interpenetrating network is constructed, and the chitosan-sodium alginate-oxidized sodium alginate ternary interpenetrating network structure is formed. The stability is improved by utilizing the synergistic effect of triple mechanisms of electrostatic interaction, Schiff base chemical bonds and zinc ion coordination.

The lithium secondary battery comprises a positive electrode, a negative electrode, a diaphragm and a polymer electrolyte, the polymer electrolyte contains the flame-retardant microcapsule, the flame-retardant microcapsule has a core-shell structure, a copolymer material containing one or more of an amide group, an ester group and an ether group is taken as a shell layer, and a flame retardant is taken as a core; the rupture collapse temperature of the flame-retardant microcapsule shell material is 60-120 DEG C, the melting point of the flame retardant is 20-120 DEG C, and the rupture collapse temperature of the copolymer material is higher than the melting point of the flame retardant. The lithium secondary battery disclosed by the invention has excellent flame retardance, the flame-retardant microcapsule added in the lithium secondary battery can be broken and collapsed when the battery is in thermal runaway, and the flame retardant is quickly released, so that the thermal runaway is actively defended in advance from the interior of the battery, and the electrochemical performance of the battery is not reduced.

The invention discloses a lithium iron manganese phosphate positive electrode material and a preparation method thereof, a positive electrode plate and a secondary battery, and belongs to the technical field of lithium iron manganese phosphate batteries, the lithium iron manganese phosphate positive electrode material comprises a lithium iron manganese phosphate positive electrode active material and a solid electrolyte interface film located on the surface of the lithium iron manganese phosphate positive electrode active material, the solid electrolyte interface film contains C, N, F and O elements, and the ratio of the relative content of the C element to the relative content of the N element in the solid electrolyte interface film is (0.5-2): 1. According to the solid electrolyte interface film, the dissolution of manganese ions and the decomposition side reaction of the electrolyte at high voltage / high temperature are remarkably inhibited, the generation of gas is fundamentally reduced, the battery is free from flatulence phenomenon after being circulated at high temperature, and the safety and the reliability of the battery are greatly improved.

The present invention provides a negative electrode active material that can reduce the generation of ionic substances and suppress excessive decomposition of the electrolyte, thereby improving the battery cycle characteristics. [Solution] A negative electrode active material having negative electrode active material particles, the negative electrode active material particles including a porous carbon structure as a base material, the porous carbon structure having Si-C bonds inside and amorphous low-valent nano-silicon oxide dispersed in the surface layer, and at least a portion of the low-valent nano-silicon oxide having tetravalent silicon oxide capable of absorbing and desorbing Li.

The invention discloses a preparation method of a rare earth element doped nickel-based selenide nano-material and application of the rare earth element doped nickel-based selenide nano-material in electro-catalysis water full-hydrolysis reaction. According to the method, nickel salt, cerium salt, selenium dioxide and potassium chloride are prepared into electrolyte, and the electrolyte is subjected to electro-deposition on a foamed nickel substrate to obtain Ce-doped Ni0.85Se nanoparticles growing on foamed nickel. The crystal structure and electron distribution of Ni0.85Se are optimized by doping trace rare earth element cerium, so that the HER and OER performances of the Ni0.85Se are greatly improved. The prepared catalyst is self-supporting closely-packed nanoparticles, the formed amorphous structure is easy to expose more active sites, the catalyst has good electrocatalytic hydrogen evolution and oxygen evolution performance under alkaline conditions, the overpotential in electrocatalysis of nickel-based selenide is greatly reduced, and the electrocatalytic performance of nickel-based selenide is improved. And excellent electro-catalytic activity is shown in electro-catalytic water full hydrolysis. And the self-supporting electrode is not easy to fall off due to generation of bubbles in the reaction process, so that the working stability of the catalyst is improved.

The method comprises the following steps: weighing an oxide precursor of metal indium, an oxide precursor of metal M, an ammonium salt and a lithium salt according to a chemical formula of indium-based halide, fully mixing, and calcining in an inert atmosphere to obtain the indium-based halide solid electrolyte. Forming an indium-based halide solid electrolyte through a solid-phase reaction; wherein M is selected from at least one of magnesium, calcium, strontium, barium, aluminum, gallium, indium, bismuth, scandium, yttrium, zinc, germanium, tin, lanthanum, cerium, samarium, gadolinium, holmium, erbium and ytterbium. The method can greatly simplify the synthesis process, reduce the raw material cost and realize industrial batch preparation.

The invention relates to a composite binder, an electrolyte membrane, a preparation method and a battery. The composite binder comprises a binder main material and cross-linked molecules, the binder main material has a first functional group; the cross-linked molecule comprises a main chain and second functional groups, the main chain comprises a dynamic cross-linked structure sensitive to heat, the dynamic cross-linked structure comprises at least one of reversible chemical bonds and heat-sensitive functional groups, and the two ends of the main chain are provided with the second functional groups which are combined with the first functional groups in a reaction mode. The problem of poor mechanical property of the binder in the related art can be solved.

The invention discloses a tab protection interlayer, a full-tab battery cell and a cylindrical battery with a shell electrode, a non-adhesive area and an adhesive area are arranged on the tab protection interlayer, so that the non-adhesive area is attached to a tab but is not adhered to the tab, and the adhesive area is adhered to a small part of tab root area and is adhered to the end part of a roll core main body at the same time; the probability that the full tab is pulled by the adhesive tape to rebound is reduced to a great extent. When the full tab is kneaded, the interlayer can be pressed towards the center direction of the roll core to form a bending structure, so that the area of an extruded area of the interlayer is reduced, and the interlayer can be adhered to a small part of area of the root part of the tab and an adhesive area on the roll core main body by virtue of the bending structure, so that the roll sleeve and wrinkles are effectively prevented from being extruded by a shell. And the interlayer can also form an elastic sealing ring structure between the shell and the roll core main body, so that the electrolyte is prevented from leaking to the negative electrode end of the cylindrical battery with the positive electrode shell by combining the adhesion sealing effect of the adhesive glue of the interlayer, and the short circuit between the tab and the shell is avoided.

The invention provides a cover plate assembly and a battery pack. The cover plate assembly comprises a cover plate, a pole, a first sealing element and a second sealing element. The cover plate comprises a first metal piece and a second metal piece sleeved outside the first metal piece. The first metal piece is provided with a through hole. And the pole is arranged in the through hole in a penetrating manner. The first sealing piece is arranged between the pole and the first metal piece; and the second sealing piece is connected with the first metal piece, or the second metal piece, or the second sealing piece is arranged between the first metal piece and the second metal piece, or the second sealing piece is connected with the pole. The second sealing piece is configured to prevent the electrolyte from flowing between the first metal piece and the second metal piece. Therefore, electrochemical corrosion caused by the fact that the electrolyte intrudes into the area between the first metal piece and the second metal piece can be prevented, the safety of the cover plate assembly is improved, and the service life of the cover plate assembly is prolonged.

The invention relates to the technical field of water-based energy storage batteries, in particular to a two-phase electrolyte for a water-based zinc ion battery and a preparation method of the two-phase electrolyte, and the two-phase electrolyte comprises soluble zinc salt, water and quaternary ammonium nitrate; the soluble zinc salt comprises one of zinc trifluoromethanesulfonate, zinc bis (trifluoromethylsulfonyl) imide, zinc acetate, zinc sulfate and zinc chloride, and the molar concentration of the soluble zinc salt is 1-5 mol / L; the quaternary ammonium nitrate is one or more than two of tetramethylammonium nitrate, tetraethyl ammonium nitrate, tetrabutyl ammonium nitrate, hexadecyl trimethyl ammonium nitrate and octadecyl trimethyl ammonium nitrate, and the molar concentration of the quaternary ammonium nitrate is 1-3 mol / L. The preparation method is simple, convenient and efficient, the reversibility of the zinc anode is optimized, the method is crucial for promoting the design of a practical water-based zinc ion battery, and the application of the zinc-based battery in the field of energy storage is further accelerated.

A lithium-ion secondary battery having excellent discharge characteristics even in a low-temperature environment is provided. The lithium-ion secondary battery includes a positive electrode, a negative electrode, and an electrolyte solution. The positive electrode includes lithium cobalt oxide with a median diameter (D50) of greater than or equal to 1 μm and less than or equal to 12 μm. The lithium cobalt oxide contains magnesium in its surface portion. The negative electrode includes a graphite particle, a silicon particle, and a polymer including a carboxy group. The electrolyte solution contains a mixed solvent of a fluorinated cyclic carbonate and a fluorinated chain carbonate.

The invention discloses an electrolyte cylinder curled edge measurement and defect detection device, and relates to the field of electrolyte cylinder detection. The detection table is arranged below the carrier plate, and the electrolyte cylinder is conveyed to the detection table through the carrier plate; the jacking mechanism is arranged on the detection table at the lower part of the carrier plate and comprises a plurality of groups of jacking rollers which are symmetrically arranged and a driving mechanism; when the electrolyte cylinder is conveyed to the position over, the electrolyte cylinder is jacked up from the carrying plate through the jacking rolling wheels, and a cylinder body of the electrolyte cylinder is lifted; the detection mechanism is mounted above the carrier plate through a bracket and comprises two groups of camera lenses, and the camera lenses are aligned to the curled edges on the two end surfaces of the electrolyte cylinder; when crimping images are shot, the driving mechanism drives the jacking roller to rotate, the electrolyte cylinder is driven to circumferentially roll at the position of the detection table, and the camera lens continuously shoots the crimping images of the two end faces of the electrolyte cylinder. The problems that traditional manual detection is low in efficiency and poor in precision are solved, and the device has the advantages that all-round continuous detection of the curled edge of the electrolyte cylinder is achieved, and the measurement precision and efficiency are improved.

The application relates to a cylindrical battery monomer, a battery and a power utilization device. The cylindrical battery monomer comprises electrolyte, an electrode assembly and a shell. The shell contains the electrolyte and the electrode assembly. The electrolyte comprises an electrolyte salt, and the electrolyte salt comprises a hexafluorophosphate. The shell comprises a shell body and a film layer. The film layer is arranged on at least a surface of the shell body facing the electrode assembly. The base element of the film layer is a nickel element. The use reliability and the cycle performance of the cylindrical battery monomer in the embodiment can be improved.

The invention discloses a secondary battery and an electric device, and belongs to the technical field of secondary batteries. The secondary battery comprises a positive electrode plate, a negative electrode plate and an electrolyte, the positive electrode plate comprises a positive electrode material layer, the positive electrode material layer comprises a positive electrode material, the positive electrode material comprises lithium iron phosphate, the electrolyte comprises a cyclic sulfate compound, the cyclic sulfate compound comprises an electron donating group, and the cyclic sulfate compound comprises an electron donating group. The negative electrode plate comprises a negative electrode material layer, and when the secondary battery is charged to a full charge state, the negative electrode material layer comprises an iron element and LiC6. By regulating and controlling the mass percentage content a% of electron donating groups in the electrolyte, the mass percentage content b% of LiC6 in the negative electrode material layer and the mass content cppm of the iron element in the negative electrode material layer, b / (10a1 / 2 + c) is within a suitable range, active lithium is effectively compensated, and side reactions between the electrolyte and the positive electrode and the negative electrode can be reduced, so that the cycle life and the safety of the battery are both considered.

According to the lithium battery and the preparation method thereof provided by the invention, dual mechanisms of free radical polymerization and ring-opening polymerization are combined, a stable double-crosslinking structure gel electrolyte constructed by two polymers can be obtained in an in-situ polymerization process, and the mechanical strength and the thermal stability are improved; by regulating and controlling the ratio of an epoxy monomer to an acrylate monomer, firstly, room-temperature ring-opening polymerization is performed, so that part of in-situ gel is formed before formation, smooth formation of a gel interface is ensured, the first coulombic efficiency of the battery is not influenced, and meanwhile, the dosage of the acrylate monomer and a corresponding thermal initiator is reduced; high-temperature treatment is carried out after formation, so that the interface aging of the battery is stable, the cycle life of the battery is prolonged, the acrylate monomers are polymerized, the high temperature continues to promote the polymerization of the residual epoxy monomers, the polymerization conversion rate is favorably increased, and the high-pressure resistance and oxidative decomposition resistance of the gel electrolyte are improved.