562 results about "Interface impedance" patented technology

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 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 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 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 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.

The invention discloses a preparation method of a solid-state electrolyte based on chemical bonding of a silane coupling agent and a sulfide solid-state electrolyte and a preparation method of a solid-state lithium battery. A halogen ion competitive adsorption effect of a first electrolyte is cooperated with a compact siloxane network formed by the silane coupling agent; the sulfide solid electrolyte is effectively inhibited from reacting with moisture in air, electrochemical performance attenuation is delayed, the first electrolyte reacts with lithium metal to generate a stable SEI layer to inhibit dendritic crystal growth, and a wide electrochemical stable window of the second electrolyte can reduce oxygenolysis reaction with a high-voltage positive electrode, so that the electrochemical performance is improved. Chemical bonding is formed between amino groups of the silane coupling agent and lithium metal, interface contact is optimized, meanwhile, the interface ion transfer efficiency is improved through the high ionic conductivity of the second electrolyte, and the interface impedance is reduced; the defects of poor ionic conductivity and poor service life caused by poor air stability and electrochemical stability of the electrolyte in the prior art are overcome.

The invention discloses a preparation method of a polymer-sulfide solid electrolyte based on multi-scale interface design and application of the polymer-sulfide solid electrolyte in an all-solid-state lithium battery, sulfide electrolyte particles with three complementary functions of Li10SiP2S12, Li7P2S8I and Li3PS4 are utilized, and a compact and ion transmission path optimized structure is formed in a polymer matrix through a gradient distribution technology; the micron-sized particles construct a high-speed ion conduction trunk, the nano and submicron particles are tightly filled to greatly reduce the interface impedance, meanwhile, the introduction of Li7P2S8I widens an electrochemical window from the source of the material, the self-repairing functional component on the outermost layer endows the interface with dynamic intelligent response capability, and when the interface generates microcracks, the self-repairing functional component on the outermost layer can repair the surface of the material. Dynamic bonds contained in the material can be reversibly broken and reconstructed, self-repairing of damage is achieved, the endurance capacity of an interface to mechanical and chemical strain caused by temperature change and long-term circulation is enhanced, and finally high ionic conductance, excellent interface stability and wide temperature range adaptive capacity are successfully and cooperatively achieved.

The invention discloses a sulfide-oxide composite solid electrolyte based on Lewis acid-base reaction, a preparation method of the sulfide-oxide composite solid electrolyte and a battery, and relates to the technical field of solid-state batteries. Comprising a sulfide electrolyte and a composite coating coated on the surface of the sulfide electrolyte, and the composite coating comprises an oxide electrolyte and a Lewis alkaline substance. The oxide electrolyte and the Lewis alkaline substance are adopted as the composite coating material, so that the sulfide electrolyte can be isolated from air, the air stability of the sulfide electrolyte is effectively improved, and the phenomenon that the sulfide electrolyte is subjected to oxidation-reduction decomposition in the charge-discharge process is reduced; and by-products generated in the use process of the sulfide electrolyte can be neutralized in situ by the Lewis alkaline substance, so that the great increase of interface impedance is reduced, the cycle performance and high-current stability of the battery are remarkably improved, and the problem that the interface impedance is increased in the charge-discharge process of the traditional sulfide solid electrolyte is solved.

The invention provides a positive pole piece, a solid-state battery and a preparation method of the positive pole piece, and belongs to the technical field of secondary batteries, and the positive pole piece comprises a positive current collector and a positive active material layer. Wherein the positive electrode active material layer is arranged on the positive electrode current collector, the interface layer is arranged on the positive electrode active material layer, the interface layer comprises a first polymer, and the first polymer comprises polyether sulfonate. According to the positive pole piece provided by the invention, the polymer interface layer formed by cross-linking polyether sulfonate is arranged on the surface of the positive active material layer, so that the interface contact and ion transmission efficiency between the positive pole piece and the solid electrolyte membrane are effectively improved based on good ionic conductivity, chemical stability and mechanical flexibility of the interface layer; the interface impedance between the positive pole piece and the solid electrolyte membrane is reduced, and the side reaction of a contact interface is inhibited, so that the rate capability and the cycle life of the solid-state battery are effectively improved.

The embodiment of the invention discloses a preparation method of a solid electrolyte membrane and the solid electrolyte membrane. The preparation method of the solid electrolyte membrane comprises the following steps: providing a composite fiber solution, a thermoplastic elastomer solution, a solid electrolyte matrix and a positive electrode material; performing coaxial electrostatic spinning treatment on the composite fiber solution and the thermoplastic elastomer solution to obtain a fiber adhesive; carrying out ball milling treatment on the fiber adhesive, the solid electrolyte matrix and the positive electrode material to obtain a fibration mixture; and carrying out hot rolling treatment on the fiberized mixture to obtain the solid electrolyte membrane. According to the preparation method provided by the invention, the fiber adhesive prepared from the composite fiber and the thermoplastic elastomer, the solid electrolyte matrix and the positive electrode material are subjected to ball milling and hot rolling treatment, so that the interface contact between the cathode and the electrolyte is optimized, the interface impedance is reduced, the cyclic stress is relieved, and the generation of interface cracks is inhibited; the prepared solid electrolyte membrane is high in ionic conductivity and stable in structure.

The invention relates to the field of lithium ion batteries, and discloses a lithium titanate composite material and a preparation method thereof, a negative pole piece and a preparation method thereof, a lithium battery and a battery pack. The surfaces of lithium titanate particles are sequentially coated with the nitrogen-doped carbon intermediate layer and the two-dimensional MXene material outer layer, and the MXene material outer layer is formed by bridging adjacent particles through hydrogen bonds, so that a'core-shell-bridge 'three-dimensional conductive network structure is constructed, the electronic conductivity of the lithium titanate composite material is remarkably improved, the electron / ion transmission efficiency of the lithium titanate negative electrode is improved, and the lithium titanate negative electrode has a good application prospect. The lithium ion battery has excellent rate capability and cycle performance; and through collaborative optimization of the three-dimensional composite material and the electrolyte, the interface impedance is reduced, and polarization is inhibited, so that the lithium battery still keeps high capacity and long cycle stability under ultrahigh rate, and meanwhile, the problems of discontinuous conductive network and high interface impedance in the prior art are solved. And excellent rate capability and cycle performance can be achieved under ultrahigh rate.

The invention provides a gel electrolyte with a controllable polymerization degree, a preparation method of the gel electrolyte, a semi-solid lithium ion secondary battery and a preparation method of the semi-solid lithium ion secondary battery, and relates to the technical field of lithium ion batteries. Raw materials for preparing the gel electrolyte comprise a cyclic ether monomer, an initiator and a polymerization inhibitor; the cyclic ether monomer is subjected to ring opening polymerization to obtain an ether polymer; the polymerization inhibitor is an inorganic lithium salt, and the polymerization degree of the gel electrolyte is determined by the dosage of the polymerization inhibitor and the dosage of the initiator. The gel electrolyte provided by the invention has the fluidity advantage of a liquid electrolyte and the flexibility advantage of a solid polymer electrolyte, and is beneficial to maintaining a stable contact interface between the electrolyte and an electrode, reducing interface impedance and improving ion transmission.

The invention discloses a high-voltage lithium ion battery capacity compensation type electrolyte with a slow release effect, and relates to the technical field of electrolyte preparation. The electrolyte comprises a lithium salt, an organic solvent, a cosolvent and a lithium supplement agent, the cosolvent is a compound containing a nitrogen-containing heteroaromatic ring, and the nitrogen-containing heteroaromatic ring is modified with a boron group and / or a strong electron withdrawing group. According to the cosolvent, the solubility of the lithium supplement agent in an electrolyte solvent can be remarkably improved, meanwhile, the cosolvent and the lithium supplement agent can jointly participate in CEI forming an organic-inorganic hybrid component, and higher Young modulus, ion diffusion rate and interface stability are achieved, so that the interface side reaction between the electrolyte and an electrode can be effectively inhibited, and the service life of the electrolyte is prolonged. And the interface impedance is reduced, so that the capacity attenuation caused by the fracture of the electrode material structure is slowed down, and the cycling stability of the battery under high voltage is comprehensively improved. According to the invention, the problems of poor capacity compensation performance and poor interface stability under high voltage of the existing electrolyte are solved.

The invention relates to the technical field of solid-state batteries, and particularly discloses an all-solid-state sulfide negative-electrode-free lithium metal battery and an assembling method thereof. The battery adopts a combination of an electrolyte membrane and electrolyte powder as an electrolyte layer, the electrolyte membrane is close to a positive electrode side, and the electrolyte powder is close to a negative electrode side. According to the structure, the compaction density and density of the electrolyte layer are remarkably improved, the growth of lithium dendrites is effectively inhibited, the interface impedance is reduced, and the volume change of the positive electrode is buffered. The assembly method comprises the following steps: compounding the positive electrode and the current collector, sequentially placing the electrolyte membrane, the electrolyte powder and the negative electrode plate, and carrying out pressure-maintaining molding under a specific pressure. Experiments show that the battery has high initial specific discharge capacity, long cycle life and high capacity retention rate, and is suitable for large-scale solid-state battery manufacturing.

The invention belongs to the technical field of development and manufacturing of solid-state electrolyte materials and solid-state lithium batteries, and particularly relates to an all-solid-state oxide-polymer electrolyte membrane as well as a preparation method and application thereof. The electrolyte membrane comprises a polymer matrix, a lithium salt, butanedinitrile, lithium lanthanum zirconium tantalum oxide and graphite phase carbon nitride, the polymer matrix, the lithium salt, the butanedinitrile, the lithium lanthanum zirconium tantalum oxide and the graphite phase carbon nitride are uniformly mixed to form a solid film; the polymer matrix is polyacrylonitrile and forms a framework of the electrolyte membrane; the lithium salt, the butanedinitrile, the lithium lanthanum zirconium tantalum oxide and the graphite phase carbon nitride are at least physically and uniformly dispersed in the polymer matrix. The electrolyte membrane can be prepared through the steps of slurry preparation, defoaming treatment, membrane forming processing, drying and curing and the like, and can be used in a solid-state lithium battery, so that the contact between the electrolyte membrane and an electrode interface is improved, side reaction is inhibited, the ion transmission efficiency and mechanical property are improved, the interface impedance is reduced, and the cycling stability and safety of the solid-state lithium battery are enhanced.

The invention discloses a solid electrolyte membrane, a preparation method and a lithium battery. The solid electrolyte membrane comprises a polymer electrolyte, the structure of the polymer electrolyte is a hyperbranched polymer, a molecular chain of the polymer electrolyte contains a polyoxyethylene chain segment, ether oxygen atoms in an amorphous phase region can form coordination with lithium ions, migration of the lithium ions is facilitated, and the ionic conductivity of the solid electrolyte membrane is improved; besides, a nitrogen and sulfur element annular structure is introduced into the hyperbranched polymer, so that the mechanical strength of the solid electrolyte membrane can be effectively improved, the ionic conductivity of the solid electrolyte membrane can be further improved, the interface impedance can be reduced, and the comprehensive performance of the battery on safety performance and electrical performance is improved.

The invention belongs to the field of positive electrode materials, and particularly relates to a core-shell ferromanganese phosphate precursor, a modified lithium ferric manganese phosphate material, a preparation method and application of the modified lithium ferric manganese phosphate material and a lithium ion battery. The core-shell ferromanganese phosphate precursor comprises a core and a shell wrapping the core, and the core is Fe3 (PO4) 2; the shell is MnxFe1-x (PO4) y (ferromanganese phosphate), x is more than or equal to 0.1 and less than or equal to 0.9, and y is more than or equal to 0.67 and less than or equal to 0.75. The invention provides a core-shell ferromanganese phosphate precursor which takes Fe3 (PO4) 2 as a core and MnxFe1-x (PO4) y as a shell, and when the core-shell ferromanganese phosphate precursor is used for preparing lithium ferromanganese phosphate, the problem of component segregation is solved, and the Jahn-Teller effect of manganese is reduced; especially for subsequent doping and coating, doping segregation is expected to be reduced, coating interface impedance is reduced, and rapid charging of the prepared material and cycling stability under large current can be remarkably enhanced.

The invention discloses a method for removing residual alkali on the surface of a high-nickel positive electrode material in a ternary lithium battery and application of the method, and belongs to the technical field of lithium ion battery positive electrode materials. After the lithium ion ternary positive electrode material is subjected to coating treatment, residual alkali compounds on the surface of the lithium ion ternary positive electrode material are remarkably reduced, and a coating material protection layer can be constructed on the surface of the lithium ion ternary positive electrode material in situ; therefore, an electrode / electrolyte interface structure is strengthened, side reaction and interface impedance are inhibited, and the specific discharge capacity and rate capability of the battery are remarkably improved. The method is simple and convenient in process and mild in condition, and has a good industrial application prospect.

The invention discloses a capacity compensation type electrolyte for a high-voltage lithium ion battery as well as a preparation method and application of the capacity compensation type electrolyte, and relates to the technical field of electrolyte preparation. The electrolyte comprises a lithium salt, an organic solvent, a first additive and a second additive, the first additive can remarkably improve the solubility of the second additive in an electrolyte solvent, so that the compensation effect of the second additive on the capacity is enhanced; meanwhile, the additive disclosed by the invention can form a compact and stable positive electrode electrolyte interface film (CEI), so that the continuous decomposition of the electrolyte and the generation of byproducts are effectively inhibited, the interface impedance is reduced, and the capacity attenuation is slowed down. The problem that an existing electrolyte is poor in capacity compensation performance is solved.

The invention provides a high-nickel ternary material with gradient doping of high-valence elements, a preparation method of the high-nickel ternary material and a solid-state battery, and relates to the field of solid-state battery preparation. The high-nickel ternary material comprises high-valence elements, and the high-valence elements comprise Ta, W, Zr and Nb. Through gradient doping distribution design of Ta, W, Zr and Nb elements, collaborative optimization of high activity of the high-nickel ternary material in a core area and high stability of the high-nickel ternary material in a surface area is realized, the problems of particle breakage, ion mixing, interface impedance and the like are effectively relieved, and the requirements of the solid-state battery positive electrode material in high-performance application are met.

The invention provides a coated microcrystal lithium-rich manganese-based positive electrode material as well as a preparation method and application thereof. The positive electrode material is a lithium-rich manganese-based positive electrode material which is prepared from a lithium-rich manganese-based precursor and has primary particles formed in situ and secondary spheres with surface coatings. The positive electrode material has a unique core-shell structure, the core is a microcrystal lithium-rich material, the shell is a nanoscale solid electrolyte layer, and the shell layer coats primary particles and secondary spheres at the same time; the structure effectively inhibits the interface side reaction between the positive electrode material and the solid electrolyte, and stabilizes the interface structure; a continuous and short Li and charge transmission path is provided, the interface impedance in an all-solid-state battery is remarkably reduced, and the rate capability and the cycling stability of the material are improved.

The invention relates to the field of battery performance monitoring and early warning, in particular to a solid-state battery interface impedance monitoring and life early warning system which comprises a signal acquisition module, an impedance analysis module, a life prediction module and an early warning module. The signal acquisition module acquires interface impedance, temperature, pressure and electrochemical data of the solid-state battery in real time; the impedance analysis module analyzes, decouples and quantifies contribution values of the positive electrode interface, the negative electrode interface and the electrolyte body to the total impedance through relaxation time distribution (DRT); the life prediction module carries out parameter identification by adopting an improved adaptive genetic algorithm based on a contribution value and a multi-parameter collaborative optimization model of temperature, pressure, charge-discharge rate and the like, and predicts the residual life; and the early warning module generates an early warning signal when the residual life is lower than the threshold value or the contribution value is abnormal. Decoupling of the interface impedance and prediction of the service life are achieved, and the reliability and safety of solid-state battery management are effectively improved.

The invention discloses a positive pole piece, a preparation method thereof and an all-solid-state lithium battery assembly, and relates to the technical field of batteries. The positive pole piece comprises a positive current collector and a positive active layer arranged on the surface of the positive current collector, the positive active layer is directly formed on the surface of the positive current collector, and an active material of the positive active layer is of a directional crystal structure. The positive electrode active layer in the positive electrode plate provided by the invention only contains the active material, and all substances in the positive electrode active layer participate in the electrochemical oxidation-reduction reaction, so that the effective load of the active material can be improved, the ion conduction efficiency in the positive electrode can be improved, and the rate capability and the cycle performance of the all-solid-state lithium battery can be improved. Meanwhile, the active material in the positive electrode active layer provided by the invention is of an oriented crystal structure, so that oriented conduction of lithium ions is facilitated, the rate capability of the prepared all-solid-state lithium battery can be further improved, and the interface impedance is reduced.

The invention provides a composite silicon-carbon negative electrode material and a preparation method thereof, a negative electrode plate and a battery. The composite silicon-carbon negative electrode material comprises a silicon-carbon composite core, and a gradient pore carbon buffer layer and a dynamic self-healing binder layer which sequentially coat the surface of the silicon-carbon composite core, a branched carbon nanostructure grows in the pore wall of the gradient pore carbon buffer layer, the dynamic self-healing binder layer partially permeates into the pores of the gradient pore carbon buffer layer, the dynamic self-healing binder layer contains dynamic disulfide bonds, and the dynamic self-healing binder layer comprises a composite binder and a conductive high-molecular polymer. According to the invention, the gradient pore buffer layer is arranged on the surface of the silicon-carbon particles, and meanwhile, the self-healing binder containing dynamic disulfide bonds is used for permeation filling, so that three-dimensional cooperative regulation and control of graded dissipation of expansion stress, self-repairing of microcracks and ion / electron dual-path conduction are realized; the three core problems of electrode pulverization caused by volume expansion, interface impedance sharp increase and long circulation capacity attenuation are thoroughly solved.

The invention discloses a sulfide all-solid-state battery silicon negative electrode binder and a preparation method and application thereof, and belongs to the technical field of all-solid-state batteries. The silicon negative electrode binder for the sulfide all-solid-state battery comprises a poly (acrylic acid-co-poly (ethylene glycol) methacrylate) grafted metal nanowire compound, can be well adhered to a pure silicon negative electrode, has excellent mechanical performance and also endows interface impedance regulation and control capability; on one hand, the tolerance to the volume change of the pure silicon negative electrode can be greatly improved, and cracks and pulverization in silicon can be effectively prevented, so that the pure silicon negative electrode has excellent cycle performance; and on the other hand, the interface impedance between the pure silicon negative electrode and the sulfide electrolyte can be effectively reduced, so that the pure silicon negative electrode has excellent rate capability. In addition, the sulfide all-solid-state battery silicon negative electrode binder is obtained only through two-step reaction, the preparation process is greatly simplified, meanwhile, the characteristic of high yield is achieved, and large-scale production is easier.

The invention provides a negative electrode current collector, an all-solid-state battery and electric equipment, and particularly relates to the technical field of batteries. The negative current collector comprises a current collector substrate, a first coating and a second coating, wherein the first coating is arranged on the surface of at least one side of the current collector substrate; the second coating is arranged on one side, deviating from the current collector substrate, of the first coating; wherein the first coating comprises a first lithium-philic material, an ion-conducting material and an electron-conducting material, and the ion-conducting material comprises a high-entropy sulfide solid electrolyte; the second coating layer includes a second lithium-philic material. According to the invention, the functionally gradient double-layer composite coating is constructed on the surface of the current collector substrate, so that the problems of non-uniform lithium deposition, high interface impedance and poor cycling stability in the prior art can be effectively improved.

The invention discloses a solid-state battery bidirectional DCDC multi-target optimization control system integrated with a BMS, and belongs to the technical field of battery management systems, and the system comprises an acoustic library building module which is used for applying current pulses of different amplitudes and rates, and collecting a high-frequency broadband sound wave response spectrum; analyzing the propagation speed, attenuation characteristics and frequency spectrum change of sound waves in the multilayer structure, and establishing an acoustic characteristic base library; the risk identification module is used for applying a micro-current detection pulse in a predetermined mode and capturing a transient acoustic response; accurate sensing of the microscopic physical state of the solid-state battery under the dynamic load working condition can be achieved, high-power charging and discharging and working condition abrupt change scenes can be rapidly adapted, the power response timeliness and the control precision are improved, meanwhile, global optimal balance of efficiency, service life and power stability is achieved, uneven deposition of lithium ions is restrained, and the service life of the solid-state battery is prolonged. Interface impedance and failure risks are reduced, and safe and reliable operation of the system is guaranteed.

The invention provides a bifunctional interface lithium-rich manganese-based positive electrode material as well as a preparation method and application thereof, and belongs to the technical field of lithium ion battery positive electrode materials. The bifunctional interface lithium-rich manganese-based positive electrode material comprises a lithium-rich manganese-based layered oxide core particle, an inner negative thermal expansion inorganic layer coating the surface of the lithium-rich manganese-based layered oxide core particle, and an outer fast lithium ion conducting layer coating the outer side of the inner negative thermal expansion inorganic layer. Through the synergistic effect of inner and outer coating layers, mechanical regulation and control and chemical / ion regulation and control are simultaneously realized on the particle size. Compared with a scheme which only adopts an inert coating, a single lithium ion conductive coating or a single negative thermal expansion coating, the method has the advantages that the thermal-chemical-mechanical coupling failure problem of a positive electrode / solid electrolyte interface in the all-solid-state battery can be more comprehensively solved, relatively low interface impedance, smaller voltage attenuation and higher cycling stability are realized, the preparation process is simple, and the preparation cost is low. The method is suitable for large-scale production.

The invention provides a composite solid electrolyte based on a porous meta-aramid nanofiber membrane and a fluorinated metal organic framework. A preparation method of the composite solid electrolyte comprises the following steps: preparing a porous poly (m-phenylene isophthalamide) nanofiber membrane; the fluorinated metal organic framework is prepared through two-step heat treatment synthesis and fluorination modification; and finally, coating the nanofiber membrane with a polymer electrolyte matrix comprising a fluorinated metal organic framework, polyethylene oxide and lithium salt to prepare the composite solid electrolyte. Through the synergistic effect of the porous polyisophthaloyl metaphenylene diamine nanofiber membrane and the fluorinated metal organic framework, while the mechanical strength and dendritic crystal inhibition capability of the composite solid electrolyte are remarkably improved, lithium ion transmission is effectively promoted, and the interface impedance is reduced; the prepared composite solid electrolyte is suitable for preparing a solid lithium metal battery with high safety and high performance.