918 results about "Interface impedance" patented technology

The invention discloses a composite polycrystalline positive electrode material which is prepared by permeating and coating a polycrystalline positive electrode material with an oxyhalide solid electrolyte, and the oxyhalide solid electrolyte comprises one or more of Li-Ta-O-Cl, Li-Nb-O-Cl, Li-Zr-O-Cl and Li-Al-O-Cl. The specific oxyhalide electrolyte is adopted to carry out permeation coating on the polycrystalline positive electrode material, uniform coating on the surface of the polycrystalline positive electrode material and grain boundaries in particles is completed, capacity utilization in the particles of the polycrystalline positive electrode material is achieved, and the capacity utilization rate of the particles of the polycrystalline positive electrode material is improved through the coating effect of the oxyhalide with high ionic conductivity. Ion transmission inside and in gaps of the polycrystalline positive electrode material particles is regulated, interface impedance is reduced, energy density is improved, and the application prospect is wide.

The invention provides a positive pole piece. The positive pole piece comprises a positive current collector, a first material layer arranged on at least one surface of the positive current collector, and a second material layer arranged on the surface, far away from the positive current collector, of the first material layer, the first material layer comprises an active material A and an active material B; the second material layer comprises an active material C; the active material A is selected from lithium iron phosphate and / or lithium manganese iron phosphate; the active material B is selected from one or more of nickel cobalt lithium manganate, lithium cobalt oxide, lithium manganate and nickel lithium manganate; the active material C is selected from one or more of nickel cobalt lithium manganate, lithium cobalt oxide, lithium manganate and nickel lithium manganate; by using the positive pole piece provided by the invention, the interface impedance of the pole piece can be reduced, the problem that the expansion rates of different areas of the pole piece are different is solved, and the cycle life of the battery is prolonged.

The invention discloses a preparation method and application of a sulfide solid electrolyte membrane based on a gradient polymer / ionic liquid composite binder, and an all-solid-state battery, and belongs to the technical field of all-solid-state batteries. The method comprises the following steps: firstly coating a polymer / ionic liquid / sulfide electrolyte composite layer through a gradient coating process, filling particle gaps under low pressure by utilizing the plasticizing effect of ionic liquid, and reducing the porosity of an interface; and then coating a polymer / sulfide electrolyte surface layer to provide mechanical support and inhibit side reaction of the electrode. According to the design, the electrolyte membrane still keeps high ionic conductivity under the working pressure of a commercial power battery module, and the interface impedance is reduced compared with that of a traditional homogeneous membrane. Through the innovative gradient structure and material combination, the ion transmission bottleneck of the sulfide electrolyte under the low-pressure condition is solved, excellent interface stability and process compatibility are achieved, and a key technical scheme is provided for all-solid-state battery industrialization.

The invention discloses an electroencephalogram sensing electrode and a using method thereof.The electroencephalogram sensing electrode comprises a shell assembly, the shell assembly comprises a shell, a base and a top cover, the shell and the base are connected to form a slow-release probe containing cavity, the shell and the top cover are connected to form a liquid storage cavity, and a fluid valve, a slow-release material, a capillary hole plug, a rapid flow hole and a slow flow hole are arranged in the shell assembly; a semi-dry electrode is made by injecting conductive liquid or a wet electrode is made by injecting conductive paste, and through a fluid valve, a slow-release material, a capillary hole plug, a quick flow hole and a slow flow hole, the electrode can quickly supply liquid to the position between the electrode and the scalp to reduce resistance and slowly supply liquid to reduce resistance, and the electrode-scalp interface impedance can be quickly reduced and can be balanced and stabilized for a long time. The electrode has the advantages that the electrode can be used as a semi-dry electrode by injecting conductive liquid, can also be used as a wet electrode by injecting conductive paste, and has the functions of storing the conductive liquid for a long time without releasing the conductive liquid when the electrode is idle and supplying the conductive liquid in two modes of fast and slow to reduce scalp-electrode impedance when a user wears the electrode to acquire signals.

The invention provides a solid electrolyte and a preparation method and application thereof, the solid electrolyte comprises a solid electrolyte matrix and a coating layer existing on the surface of the solid electrolyte matrix, and the coating layer comprises an inorganic substance with a sublimation temperature less than 500 DEG C; the coating rate of the solid electrolyte is greater than or equal to 90%. According to the solid electrolyte provided by the invention, the coating layer is introduced to the surface of the solid electrolyte matrix, the inorganic matter with the sublimation temperature less than 500 DEG C is used as the coating material, and the coating rate is greater than or equal to 90%, so that the interface impedance between the solid electrolyte and the electrode material can be reduced, and the microdefects and pores on the surface of the solid electrolyte matrix can be filled up; meanwhile, the solid electrolyte matrix can be prevented from being directly exposed in the environment, chemical bonds can be formed between the solid electrolyte matrix and some metal elements in the solid electrolyte matrix, and therefore the ionic conductivity retention rate and stability of the solid electrolyte can be improved, and the specific capacity and the first coulombic efficiency of a battery can be improved when the solid electrolyte is applied to the battery.

The invention provides a coated modified high-nickel ternary positive electrode material, a preparation method and a lithium ion battery, the coated modified high-nickel ternary positive electrode material comprises a high-nickel ternary matrix and a coating layer containing an oxide solid electrolyte, the coating layer is coated outside the high-nickel ternary matrix and accounts for 1%-3% of the mass of the high-nickel ternary matrix; the oxide solid electrolyte comprises Li < 3x > La < 2 / 3-x > TiO < 3 > (0 lt; x < = 0.16), Li < 7 > La < 3 > Zr < 2 > O < 12 >, Li < 1 + y > Al < y > Ti < 2-y > (PO < 4 >) < 3 > (0 lt; y < = 0.5); the ionic conductivity of the oxide solid electrolyte is greater than or equal to 1 * 10 <-4 > S / cm. The selected oxide solid electrolyte has high ionic conductivity and electronic insulativity, a rapid lithium ion transmission channel can be provided, interface side reaction can be inhibited, the rate capability and the cycling stability of the material can be remarkably improved, and when the oxide solid electrolyte forms a coating layer, the coating layer is not prone to deformation, and the service life of the material is prolonged. The interface bonding strength with a high-nickel ternary matrix can be improved through chemical bonding, the interface impedance can be remarkably reduced, and the dynamic performance of the material is improved.

The invention provides a high-stability lithium-rich manganese-based positive electrode material and a preparation method thereof, and relates to the technical field of lithium-rich manganese-based positive electrode materials, and the method comprises three steps of preparation of a homogeneous precursor, solid-state mechanical fusion doping and coating, and high-temperature sintering; a lithium-rich manganese-based precursor is prepared by adopting a homogeneous coprecipitation process, uniform distribution of metal ions is ensured, then an aluminum source, a zirconium source and a fluorine source are introduced as doping agents, phosphate and a titanate coating agent are combined, doping and coating integrated treatment is realized through mechanical ball milling, and the lithium-rich manganese-based composite material is obtained. And finally, mixing with a lithium source in an argon atmosphere, and carrying out high-temperature sintering of temperature programming and staged heat preservation to form a stable composite coating layer in situ. Therefore, manganese ion migration is effectively inhibited through lattice doping, a layered structure is prevented from being converted into spinel or rock salt phase, meanwhile, a nanoscale ion / electron transmission channel is constructed, interface impedance is reduced, and the charging and discharging efficiency under high voltage is improved.

The invention relates to an in-situ cured silicon-based composite negative pole piece as well as a preparation method and application thereof. The silicon-based composite negative pole piece comprises a negative pole piece and a polymer electrolyte layer which is cured in situ and coats the surface of the negative pole piece; the polymer electrolyte layer is obtained through in-situ polymerization reaction of a precursor solution applied to the surface of the negative pole piece; the precursor solution contains a fluoroalkyl functional group; and the negative pole piece comprises a silicon-based material of which the surface is rich in hydroxyl. The composite negative pole piece disclosed by the invention not only can effectively limit the volume expansion of a silicon negative pole in a circulation process and reduce the phenomena of particle pulverization and interface separation, but also remarkably enhances the adhesive force among active substance particles, and ensures the structural integrity of the pole piece and the efficient transmission of ions and electrons. The silicon-based negative pole piece can form a stable solid-solid interface with the solid electrolyte through the polymer coating layer, so that the interface impedance is remarkably reduced, and the ion conduction efficiency is improved, thereby enhancing the cycling stability and safety performance of the battery while improving the energy density of the battery.

The invention belongs to the technical field of lithium ion battery positive electrode materials, and particularly relates to a double-strategy modified high-nickel positive electrode material as well as a preparation method and application thereof. According to the double-strategy modified high-nickel positive electrode material, a high-nickel positive electrode material serves as a matrix, surface coating and bulk phase doping are achieved at the same time through competitive doping of main group elements, a coating layer is a fast ion conductor LiLaO2 nano layer, and a bulk phase doping element is Y. The fast ion conductor coating layer can provide an additional ion channel, promote conduction of ions on the surface of the positive electrode material, reduce interface impedance and improve the rate capability of the battery. The doping elements can optimize the crystal structure of the positive electrode material and can relieve stress generated in the charging and discharging process, so that phase change and structural degradation are reduced, and the structural stability of the positive electrode material is improved.

The invention discloses a negative electrode interface modification material, a negative electrode plate, a positive electrode interface functional layer, a positive electrode plate, a solid-state battery and a power utilization device, and relates to the technical field of batteries, the negative electrode interface modification material comprises a first polymer matrix, a reinforcing filler, a conductive agent and a lithium salt, the modulus of the reinforcing filler is greater than 50 GPa. The tensile strength of the negative electrode interface modification material can be improved through the first polymer matrix, breakage of a negative electrode interface modification layer is reduced, interface impedance is reduced, meanwhile, the first polymer matrix can be matched with the expansion coefficient of a silicon-based material, and bulging of a negative electrode plate is reduced. The modulus of the reinforcing filler is greater than 50GPa, so that the modulus of the negative electrode interface modification layer can be improved, the expansion of the silicon-based active material is further inhibited, the conductive agent can relieve the problem that the flexible substrate interface of the copper foil and the negative electrode interface modification layer possibly causes unsmooth electron transmission, and the lithium salt can improve the ion conduction capability and reduce the interface impedance.

The invention relates to a composite solid electrolyte and a preparation method and application thereof. The preparation method of the composite solid electrolyte comprises the following steps: S1, mixing an inorganic filler and a fluorine-containing compound, and reacting at 70-90 DEG C under an acidic condition to obtain an inorganic filler wrapped by a fluorinated layer; then adding a fluorine ion complexing agent and a silane coupling agent for reaction to obtain a modified filler; adding a thermal decomposition type cross-linking agent into the polymer, and carrying out melt blending to obtain a cross-linked polymer; s2, uniformly mixing the modified filler, a cross-linked polymer, a lithium salt and a solvent to obtain a plurality of slurries containing the modified filler with different volume concentrations; and molding the slurry to prepare the composite solid electrolyte. According to the method, the fluorinated layer and the siloxane network are constructed step by step, so that the interface impedance is reduced, and efficient dissociation of the lithium salt is promoted; a three-dimensional network structure is combined, so that the tensile strength is improved; the modified filler is further designed in a gradient manner to improve the lithium ion transference number.

The invention relates to the technical field of material detection, in particular to a silver coating adhesive force detection method based on multi-frequency impedance imaging, which comprises the following steps: applying a dual-mode multi-frequency excitation signal to the surface of a silver coating through an attached microelectrode array, synchronously acquiring voltage-current response data, and generating a dual-mode multi-frequency impedance original data set; performing time-varying impedance phase-locked separation on the dual-mode multi-frequency impedance original data set, extracting a dynamic impedance component of a coating-matrix interface region, and reconstructing a three-dimensional sub-interface impedance distribution diagram; and outputting an adhesive force quantized value through an oscillation frequency-adhesive force conversion model according to the spatial oscillation frequency characteristics of the impedance phase in the three-dimensional sub-interface impedance distribution diagram. According to the invention, a double-phase-locked loop system is adopted to realize the time-varying component demodulation of the impedance response of the silver coating-matrix interface, the low-frequency dynamic impedance signal modulated by silver ion migration is effectively extracted, and the weak change of the interface bonding state is sensitively reflected.

The invention discloses a preparation method of an all-solid-state battery unit, the all-solid-state battery unit and an all-solid-state battery module. The preparation method comprises the following steps: 1) pressing and pre-calcining a positive electrode unit to form a sintered laminated body; (2) alternately overlapping at least one negative electrode and the sintered laminated body in the step (1) to form an all-solid-state battery laminated body, and pressurizing the laminated body; (3) carrying out low-temperature primary calcination on the all-solid-state battery laminated body in the step (2); (4) carrying out high-temperature secondary calcination on the all-solid-state battery laminated body obtained in the step (3); wherein the positive electrode unit in the step 1 comprises a solid electrolyte layer, a composite electrode layer and a current collector layer; the composite electrode layer comprises a high ion channel layer and a high electron channel layer. The stable particle space is constructed through multiple times of calcination, the interface impedance between the electrode layer and the electrolyte layer and the interface impedance between the electrode layers are reduced, the densification between the solid electrolyte and the electrode is improved, and the battery capacity and the cycle performance are improved.

The present invention discloses a method for preparing a composite solid electrolyte membrane, the composite solid electrolyte membrane comprises three layers, the first layer is a composite solid electrolyte layer containing oxide-polymer, the second layer is a sulfide solid electrolyte layer, and the third layer is a polysiloxane solid electrolyte layer; the preparation method comprises the following steps: S1, preparation of the first layer: immersing a polymer porous membrane as a substrate into the first layer slurry, coordinating ultrasound to make the first layer slurry fully fill the pores, and drying to obtain; S2, preparation of the second layer: coating the second layer slurry on the basis of the first layer, drying to obtain; S3, preparation of the third layer: coating the third layer slurry on the basis of the second layer, drying to obtain; S4, pressing: the first, second and third layers are hot-pressed by rollers to obtain. The composite solid electrolyte membrane of the present invention can effectively improve the interface contact between the solid electrolyte and the positive and negative electrodes, reduce the interface impedance, and has the characteristics of high mechanical strength, high ionic conductivity, good thermal stability, etc.

The invention discloses an artificial SEI material and a preparation method thereof, an artificial SEI film and an artificial SEI film modified negative electrode. The artificial SEI material is an organic polymer brush (CNF-g-PSSX) prepared by grafting cellulose nanofibers with polystyrene sulfonate. The polymer brush is of a crystal structure and has a firm framework; and the side chain of polystyrene sulfonate has rich-SO3 functional groups which are matched with cations in sulfonate, so that a rapid ion transmission channel is provided, high-current-density circulation can be realized, and good interface contact is ensured. Due to a special molecular topological structure and a multi-component synergistic effect, when the organic polymer brush forms an artificial SEI film, high mechanical strength, high ionic conductivity and low interface impedance can be obtained at the same time, and through strong electrostatic repulsion between a negatively charged-SO3 group and the surface of a negatively charged lithium dendrite tip, the electrochemical performance of the artificial SEI film is improved. An obvious inhibition effect is shown on the continuous growth of dendritic crystals.

The invention provides a lithium ion battery and an electric device, the lithium ion battery comprises a positive electrode, a negative electrode, a diaphragm and an electrolyte, the positive electrode comprises a positive electrode active material layer, the positive electrode active material layer comprises a positive electrode active material and an oxide solid electrolyte, and the surface of the diaphragm is provided with an oxide solid electrolyte layer; the electrolyte comprises a solvent, a lithium salt, a first additive and a second additive, the first additive comprises fluoroethylene carbonate, and the second additive comprises 1, 3-propane sultone; the lithium ion battery satisfies the following conditions: 0.72 < = (H + X) / P < = 8; 0.5 < = (A + B) / (H + X) < = 8.89; 0.16 < = H / X < = 6.4; 0.5 < = A / B < = 12. According to the lithium ion battery provided by the invention, the safety and the high and low temperature performance of the positive electrode of the lithium ion battery are remarkably improved through multi-component cooperative regulation and control, further, when the lithium ion battery meets the limitation of the relational expression at the same time, the interface impedance can be reduced to the maximum extent, and the performance of the lithium ion battery can be improved through cooperation of multi-component parameters. And synchronous optimization of thermal safety, low-temperature discharge capacity and high-temperature cycle life of the battery is realized.

The invention relates to a composite diaphragm with high ionic conductivity, a composite solid electrolyte and a preparation method thereof. The composite diaphragm is composed of a lithium lanthanum-based fluorine-doped solid electrolyte LLMOF and a base membrane, the chemical general formula of the LLMOF is Li < x > La < y > M < 1 > < z > M < 2 > < w > M < 3 > O < 6 > F, wherein M1 is a tetravalent cation, M2 is a pentavalent cation, and M3 is a hexavalent cation; 1 < x + 3y < 5, 0 < x < = 2, and 1 / 3 < y < 5 / 3; 0 < = z < = 2, 0 < = w < = 2, 0 < = u < = 2, z + w + u = 2; the base membrane is a large-aperture base membrane, and the aperture r is more than or equal to 200nm and less than or equal to 1mu m; the particle size D50 of the LLMOF is 50 nm to 1 [mu] m, and the particle size D50 of the LLMOF is less than or equal to the aperture r of the base film. According to the composite diaphragm disclosed by the invention, the LLMOF solid electrolyte with an ion channel function is introduced, so that efficient conduction of ions is realized; the particle size is matched with that of a large-aperture base membrane, the membrane can be uniformly embedded into membrane holes, a continuous conduction path is constructed, and the ionic conductivity is improved; meanwhile, the composite diaphragm has excellent thermal stability and interface wettability, interface impedance is effectively reduced, and growth of lithium dendrites is inhibited.

The invention relates to a preparation method and application of an organic-inorganic artificial composite solid electrolyte interface layer, and belongs to the technical field of lithium metal batteries. The organic polymer, the black phosphorene, the conductive carbon black and other inorganic substances are uniformly mixed to construct the organic-inorganic artificial composite interface layer, and the organic-inorganic artificial composite interface layer can induce uniform lithium deposition, reduce the local current density caused by nonuniformity and roughness of the surface of the copper current collector, reduce the lithium nucleation barrier, and improve the lithium ion battery performance. Meanwhile, the affinity of deposited lithium and a current collector is enhanced, the interface impedance of the negative-electrode-free lithium metal battery is remarkably reduced, and the lithium dendrite growth of a lithium metal negative electrode is inhibited; the cathode-free lithium metal battery assembled by adopting the copper current collector modified by the organic-inorganic artificial composite interface layer shows long cycle stability, good rate capability and remarkable safety performance, and has a wide commercial application prospect.

The invention discloses an interfacial film for an ion battery, a preparation method of the interfacial film, the ion battery and an electric device, the interfacial film for the ion battery is finally obtained by performing multi-step modification on a carbon nano tube and reacting the carbon nano tube with a prepolymer solution, so that the interfacial film can effectively reduce the interfacial impedance and promote ion transmission, and the performance of the ion battery is improved. The modified carbon nanotubes are combined with polyimide through the action of covalent bonds, so that the mechanical property of an interfacial film is improved, dendritic crystal puncture can be physically inhibited through the high mechanical strength of the interfacial film, and the cycling stability and the rate capability of the battery are improved; and meanwhile, the interfacial film can inhibit side reaction between the negative electrode and electrolyte, reduce interface impedance and promote ion transmission, so that the overall electrochemical performance of the battery is improved.

The invention relates to a preparation method and application of an electrode, in particular to a preparation method and application of an anti-reverse current self-supporting electrode for anion exchange membrane water electrolysis hydrogen production. The self-supporting (NiCoFe) 9S8 electrode is constructed by adopting a directional solid-phase synthesis strategy to overcome the challenge of performance degradation of the electrolytic cell. The preparation method comprises the following steps: firstly, depositing a precursor solution of FeS2 and CoCl2 on a nickel felt substrate, and then carrying out annealing treatment to obtain uniformly grown (NiCoFe) 9S8; the method not only ensures uniform distribution of multiple metal components, but also constructs firm chemical bonding and efficient charge transfer between the catalyst layer and the conductive substrate through solid-phase interface reaction, and effectively avoids interface impedance caused by introduction of an additional binder. Therefore, high-current-density water electrolysis hydrogen production under intermittent fluctuation power supply is realized. In 1M KOH, the cell voltage is almost not attenuated when the electrode stably operates for 2000h at 500mAcm <-2 >.

The invention relates to the technical field of lithium battery electrolytes, in particular to a preparation method of a polyether-based solid electrolyte and application of the polyether-based solid electrolyte in electrochemical devices such as lithium metal batteries. The polyether-based solid electrolyte material comprises a porous polymer skeleton, a cyclic ether monomer, a copper-based compound, a lithium salt and a plasticizing additive. The preparation method comprises the following steps: loading a copper-based compound into a porous polymer skeleton, adding cyclic ether, lithium salt and the like to carry out in-situ ring opening polymerization, cooperatively constructing a polyether-porous polymer skeleton three-dimensional network structure, and improving the mechanical strength of the electrolyte. Wherein the copper-based compound widens the chain spacing of the porous polymer, and is convenient for the cyclic ether monomer to penetrate into the skeleton; meanwhile, the in-situ ring-opening polymerization of the cyclic ether promotes the close contact between the electrolyte and an electrode, the interface impedance is reduced, and the ionic conductivity is improved. The polyether-based solid electrolyte prepared by the invention can promote stable circulation of a lithium metal battery.

The invention discloses a preparation method of a solid-state battery unit and a solid-state battery containing a composite multifunctional electrolyte layer, multifunctional integration of a single-layer electrolyte is realized through a composite material system, and compared with a traditional PE / PP diaphragm system, the proportion of an inorganic material in the composite electrolyte layer is greater than 90%, and the composite electrolyte layer has excellent high-temperature resistance and can be used for preparing a solid-state battery. And the structural integrity is kept when the battery is possibly subjected to thermal runaway. The localized adding mode of the ionic liquid and the conductive salt is optimized, and high-temperature degradation is avoided; the manufacturing process is simplified, tight interface contact between the electrolyte layer and the electrode is ensured, and impedance is reduced. Compared with a traditional liquid lithium ion battery, the solid-state battery prepared by the invention has the liquid content of less than 1%, and has high safety and cycle performance. The problems that an electrolyte layer in a traditional solid-state battery is single in function (for example, only ion conduction is concerned), the interface impedance is large, the thermal stability is poor, and the mechanical strength is insufficient are mainly solved, and the comprehensive performance and safety of the battery are improved.

The invention discloses an in-situ autocatalytic forming gel epidermal electrode, an electrophysiological signal monitoring system and an electrophysiological signal monitoring device. The gel precursor includes a supramolecular solvent selected from a specific monomer, a metal ion catalyst, an initiator, a cross-linking agent, and a hydrogen bond acceptor and a hydrogen bond donor. The gel precursor provided by the invention can perform autocatalysis to initiate crosslinking to form a sensing medium with an interlocking structure, and meanwhile, can form a stable interface structure with the skin to ensure that the gel precursor is tightly attached to epidermal tissues, and motion artifacts caused by relative displacement in a motion process are reduced to the greatest extent. According to the invention, the electrode is formed by gelling the gel precursor on the skin surface, and the electrode has low interface impedance so as to ensure high signal fidelity, excellent mechanical stability, dynamic adhesion, stable electrochemical performance and biocompatibility, and can be reliably used for a long time. The method can be widely applied to wearable equipment, electronic skin, medical equipment and the like.

The invention discloses a sulfide solid electrolyte based on ionic liquid electrowetting modification and application thereof. The preparation method of the electrolyte comprises the following steps: preparing a sulfide electrolyte into an electrolyte sheet, and coating the surface of the electrolyte sheet with an ionic liquid to form an ionic liquid film, thereby obtaining the electrolyte sheet containing the ionic liquid film; and placing the sulfide solid electrolyte between electrode plates which are arranged in parallel to assemble a parallel-plate capacitor, and applying a direct-current signal to carry out electrowetting treatment, thereby obtaining the sulfide solid electrolyte based on ionic liquid electrowetting. The specific ionic liquid is introduced into the interface of the sulfide solid electrolyte and the negative electrode for electrowetting treatment, so that the interface contact angle is effectively reduced, the interface wettability is improved, the interface impedance is reduced, the electrochemical performance of the all-solid-state battery is improved, and the cycle life of the all-solid-state battery is prolonged. The method particularly focuses on the use of imidazole and pyridine ionic liquids, and selects the appropriate ionic liquid for the lithium metal negative electrode material to realize the optimal interface modification effect.

The invention belongs to the technical field of all-solid-state sulfide lithium metal batteries, and relates to a lithium battery electrode containing an interface self-repairing coating as well as a preparation method and application of the lithium battery electrode. The electrode comprises a lithium metal negative electrode substrate and the interface self-repairing coating coated on the surface of the lithium metal negative electrode substrate, the interface self-repairing coating is internally provided with a dynamic reversible network, and the dynamic reversible network is constructed by disulfide bonds and hydrogen bonds. A layer of interface self-repairing coating is formed on the surface of a lithium metal negative electrode substrate to serve as a physical isolation barrier, metal lithium and sulfide electrolyte are isolated and prevented from being directly subjected to reduction reaction, and coating microcracks generated by volume change in lithium metal circulation can be repaired, so that the possibility of interface exposure caused by coating breakage is reduced, and the service life of the lithium metal negative electrode is prolonged. Meanwhile, good interface contact can be kept, the synergistic effect of stable interface impedance, lithium dendrite inhibition and long-term cycle performance improvement is achieved, and the long-term cycle stability of the all-solid-state lithium battery is improved.

The invention discloses a composite solid electrolyte layer, a preparation method and application, the composite solid electrolyte layer comprises a porous membrane laminated on a negative pole piece, and pores in the porous membrane and gaps between the porous membrane and the negative pole piece are filled with in-situ generated polymers. Inorganic solid electrolyte is also dispersed in the porous membrane, and lithium salt is dispersed in the polymer and the porous membrane. The composite solid electrolyte layer is obtained through in-situ polymerization of a polymer in pores in the porous membrane and gaps between the porous membrane and the negative electrode plate, and a novel interface structure with the electrode-electrolyte integration characteristic is constructed. By adopting a collaborative optimization strategy of a polymer matrix and inorganic filler double-crosslinking network system and an interface stable layer, the volume effect problem of a silicon-based negative electrode, the electrolyte interface impedance problem and the battery safety problem can be solved at the same time, so that the cycling stability and the rate capability of the lithium ion battery are remarkably improved.

The invention relates to the technical field of lithium ion batteries, in particular to a preparation method of an interface-modified high-rate lithium iron phosphate positive electrode material, which is used for solving the problems of low interface impedance, low rate capability and low energy density of the existing lithium iron phosphate. According to the preparation method, zirconium-niobium co-doped iron phosphate is used as a precursor of the lithium iron phosphate positive electrode material, a lithium ion diffusion channel is widened, the lithium ion diffusion coefficient is improved, meanwhile, an olivine structure framework is provided, a wider tunnel space is provided for lithium ion migration, zirconium-niobium provides additional electrons, and the electron conductivity is improved through cooperation of the zirconium-niobium co-doped iron phosphate and the olivine structure framework; li2ZrCl6-LiCl interface modification can isolate sulfide electrolyte from being in direct contact with a positive electrode material, and interface side reaction is inhibited; carbon nanotube coating can enhance the conductivity, reduce erosion, improve the diffusion coefficient of Li < + > and the stability of the material structure, and improve the charge-discharge rate.

The invention discloses a positive electrode composite material and a preparation method thereof, a positive electrode plate and a battery, and belongs to the technical field of batteries. The positive electrode composite material provided by the embodiment of the invention comprises an inner core, a buffer layer and a shell which are sequentially coated from inside to outside, the inner core comprises lithium manganese iron phosphate, the shell comprises lithium nickel cobalt manganese oxide, the Fermi level of the material of the buffer layer is between the Fermi level of the lithium manganese iron phosphate and the Fermi level of the lithium nickel cobalt manganese oxide, and the molar ratio of the Mn element to the Fe element in the inner core conforms to the decreasing trend in the direction from inside to outside. The material can reduce the interface impedance and the interface side reaction degree, thereby improving the rate capability and cycle life of the battery.

The embodiment of the present application provides a positive electrode material, a secondary battery and an electric device, wherein the positive electrode material comprises a core and a coating layer arranged on the surface of the core, the core comprises a sodium ion layered oxide, and the coating layer comprises a spinel lithium salt. In the embodiment of the present application, the layered positive electrode material is tightly coated by the spinel lithium salt, so that the problem that the interface impedance of the positive electrode material of the existing sodium ion battery is large and the positive electrode adhesive is easily attacked is solved.

A preparation method for a composite electrode sheet containing a solid-state electrolyte layer. A solid-state electrolyte is uniformly introduced into a solid-state battery by means of wet electrostatic atomizing spraying, so that a continuous and compact interface of a solid-state electrolyte layer can be constructed on an electrode sheet, enhancing flexible interfacial contact between the electrode sheet and the solid-state electrolyte layer, thereby reducing interface impedance, and improving the electrochemical performance of the solid-state battery.