354 results about "Interfacial impedance" patented technology

The invention relates to organic-inorganic all-solid-state composite electrolyte as well as preparation and application methods thereof, belonging to the field of lithium ion batteries. According to the organic-inorganic all-solid-state composite electrolyte, a highly-ordered three-dimensional connection network skeleton is formed by an inorganic fast lithium ion conductor, and a three-dimensional connection network is filled with a polymer and lithium salt. The organic-inorganic all-solid-state composite electrolyte which is flexible and has a controllable three-dimensional connection network structure is prepared. The electrolyte is high in lithium ion conductivity, wide in electrochemical window, good in mechanical property and stable to lithium metal. A lithium ion secondary battery assembled by a composite electrolyte membrane prepared by the method is high in capacity, stable in cycle performance, low in interface impedance and good in interface stability.

Set forth herein are electrochemical cells which include a negative electrode current collector, a lithium metal negative electrode, an oxide electrolyte membrane, a bonding agent layer, a positive electrode, and a positive electrode current collector. The bonding agent layer advantageously lowers the interfacial impedance of the oxide electrolyte at least at the positive electrode interface and also optionally acts as an adhesive between the solid electrolyte separator and the positive electrode interface. Also set forth herein are methods of making these bonding agent layers including, but not limited to, methods of preparing and depositing precursor solutions which form these bonding agent layers. Set forth herein, additionally, are methods of using these electrochemical cells.

The invention discloses an all-solid-state lithium ion battery and a preparation method thereof. The all-solid-state lithium ion battery is prepared by an ink-jet printing technology; different components are dissolved into a solvent to prepare slurry; the slurry is put into different ink boxes; designing is carried out by computer program; electrodes and electrolyte are longitudinally printed in a stepwise gradient manner; the electrolyte longitudinally changes in electrode plates in a gradient manner; the interface impedance of an electrode active material/electrolyte can be reduced by the gradient structure distribution of the electrolyte in the electrode plates; deep conduction of lithium ions is facilitated; the capacity property of the active material is put into the greatest play; and other parts, except for a current collector, of the all-solid-state lithium ion battery structure prepared by ink-jet printing form an overall lamination structure. Various components in the lamination structure are in tight contact and regular arrangement, so that the interface impedance is much lower than that of the all-solid-state lithium ion battery which is prepared in a mechanical superposition manner; and the ink-jet printing mode is convenient, fast and suitable for large-scale production.

The invention belongs to the field of all-solid-state lithium batteries, and discloses a lithium lanthanum zirconium oxide solid electrolyte. The lithium lanthanum zirconium oxide solid electrolyte comprises 60-75wt% of a polymer, 8-15wt% of a lithium salt and 15-30wt% of a lithium lanthanum zirconium oxide three-dimensional porous inorganic network, wherein the polymer is compounded in the lithium lanthanum zirconium oxide three-dimensional porous inorganic network in situ. The invention also discloses a preparation method of the lithium lanthanum zirconium oxide solid electrolyte and application of the lithium lanthanum zirconium oxide solid electrolyte in the field of lithium ion batteries. The lithium lanthanum zirconium oxide three-dimensional porous network provides a continuous lithium ion transmission channel, so that the ionic conductivity is higher. Meanwhile, due to the existence of the lithium lanthanum zirconium oxide three-dimensional porous network, certain mechanical properties are provided for the composite solid electrolyte, the growth of lithium dendrites can be inhibited, and the high-temperature performance and safety of the battery are improved. Therefore, theinterfacial compatibility and stability between the solid electrolyte and the electrode are optimized and improved, and the formed all-solid-state lithium battery has the advantages of being stable in cycle performance, high in rate capability, low in interfacial impedance and good in stability.

The invention provides an all-solid-state lithium ion battery with low interface impedance and high compatibility. The battery comprises a composite positive pole piece and a composite negative pole piece, wherein the composite positive plate and the composite negative plate are a mixture of an active substance and solid electrolyte with a certain concentration gradient, the concentration gradientis that the concentration of the active substance is gradually reduced from a current collector to the outside, the solid electrolyte is gradually increased, and the outermost layer is only a solid electrolyte layer. In order to achieve interfacial compatibility of the positive and negative composite pole pieces, a surface of the outermost solid electrolyte layer of the composite pole piece is designed into a concave-convex groove, and the concave-convex surface is coated with low-melting polymer solid electrolyte; and lastly, the composite positive pole piece and the composite negative polepiece are tightly combined in a hot-pressing manner to assemble the battery. The battery can effectively solve a problem of compatibility between an electrode material and an electrolyte layer and a problem of large interface impedance of a solid-state battery, and thereby the cycling stability of the solid-state battery is improved.

The invention belongs to the technical field of electrochemistry, and relates to an interface-modified solid garnet type battery and a preparation method thereof. A flexible gel electrolyte intermediate layer is introduced at the interface of a positive electrode/electrolyte and a negative electrode/electrolyte of the solid garnet type battery by adopting an in-situ polymerization process, beforepolymerization, the precursor of the gel electrolyte can fully infiltrate the interface of the positive and negative electrodes and fully infiltrate the interior of the positive electrode; after polymerization, the precursor is cured in situ in the positive electrode and at the interface of the positive and negative electrodes, and a cured ion conductive network is formed in the positive electrode, so that the contact between electrodes/electrolytes is greatly improved, and the interface impedance is significantly reduced. The method is simple and easy to implement, enables the electrode/electrolyte interface impedance of the solid garnet type battery to be significantly reduced, enables the cycle performance and the rate capability of the battery to be improved, and has the very good industrial application prospect.

The invention provides a lithium metal anode protective layer as well as a preparation method and application thereof. The lithium metal anode protective layer comprises a metal protective layer and apolymer protective layer, the metal protective layer is formed on a lithium metal anode plate, and at least one part of metal of the metal protective layer reacts with the lithium metal anode plate to form an alloy layer; and the polymer protective layer comprises a polymer and a lithium salt, and the polymer protective layer is formed on the metal protective layer. When the lithium metal anode protective layer is used for the battery, lithium dendrites can be prevented from being generated, the lithium metal anode is prevented from directly contacting with the electrolyte layer to react, andthe interface impedance between the negative plate and the electrolyte layer is reduced, so that the cycle performance, the rate capability, the safety performance, the service life and the like of the battery are remarkably improved.

The invention belongs to the field of equipment for measuring human body impedance and particularly relates to a flexible electrode for measuring muscle impedance and a preparation method thereof. The flexible electrode for measuring muscle impedance comprises an insulating flexible substrate, at least one pair of exciting electrode plates, at least one pair of measuring electrode plates, surface modification layers, metal leads, metal lead connectors and a polymer protective film. The exciting electrode plates and the measuring electrode plates are arranged to form an electrode array, the electrode array, the metal leads and the metal lead connectors are arranged on the insulating flexible substrate, the surface modification layers cover all the electrode plates, and the face, provided with the electrode array, of the insulating flexible substrate is covered with the polymer protective film. According to the electrode, measuring errors caused by contact interface impedance can be effectively reduced through the insulating flexible substrate and the interface modification layers, no wound or pain is generated, operation is easy and convenient, repeatability is achieved, and the electrode is suitable for being popularized.

The invention discloses a solid-state battery and a preparation method thereof. The solid-state battery is composed of a positive electrode, an organic-inorganic composite solid electrolyte diaphragmand a negative electrode. The organic-inorganic composite solid electrolyte diaphragm and the positive electrode have good chemical and electrochemical stability; and the organic-inorganic composite solid electrolyte diaphragm and the negative material have relatively small interface impedance, and growth of lithium dendrites can be inhibited. The solid-state battery prepared by the method is small in interface impedance, controllable in interface side reaction, capable of being matched with various positive electrodes and negative electrodes, and free of lithium dendritic crystal growth phenomenon, so that the solid-state battery has high specific energy and long cycle life. And the preparation process of the solid-state battery designed by the invention is matched with the existing preparation process of the lithium ion battery, so that the requirement of large-scale production is met.

The invention discloses a composite cathode material, a preparation method thereof and an application in an all-solid-state lithium battery. Positive composite materials include sulfide and conductivecarbon with thioagermanite crystal structure, in which the sulfide not only acts as the release capacity of active material, but also acts as an electrolyte to conduct lithium ions; Conducting carbonmaterials play the role of conducting electrons; The mass ratio of the sulfide to the conductive carbon material can be (20-90): (80-10). The sulfide electrolyte used in the electrolyte layer is thesame as the sulfide electrolyte used in the composite positive stage when assembling all-solid-state batteries. The obtained all-solid-state lithium battery has the advantages of simple structure, small interface impedance, small overall impedance, high safety performance, high output energy density, good cycle stability and high capacity retention rate.

The invention discloses a preparation method of an all-solid-state electrolyte battery. The preparation method comprises the steps of preparing a solid-state electrolyte layer, preparing positive electrode slurry, compounding a positive electrode layer and the solid-state electrolyte layer, compounding a negative electrode layer and the solid-state electrolyte layer and the like. The invention provides a simple and convenient interface modification method of an all-solid-state battery. The three-dimensional porous structures are formed on the two surfaces of the solid electrolyte, so that thepositive electrode material and the negative electrode material are in good contact with the solid electrolyte, the interface impedance between the solid electrolyte and the positive electrode and between the solid electrolyte and the negative electrode is reduced, the utilization rate of the active material is increased, and the capacity and cycle life of the all-solid-state electrolyte battery are further improved. And the method does not need to additionally dropwise add an electrolyte, does not need to additionally construct an interface modification layer and perform low-temperature sintering, and is easy to operate and good in effect. The invention also discloses an all-solid-state electrolyte battery which comprises the solid-state electrolyte base layer, and the positive electrodelayer and the negative electrode layer which are arranged on two sides of the solid-state electrolyte base layer.

The invention relates to a preparation process of a metal lithium negative electrode with a surface protection layer. The preparation process comprises the following steps: 1, dissolving a lithium salt or/and an inorganic solid electrolyte and a polymer and mixing in a polyimide solution to obtain a polyimide mixed solution; 2, coating the surface of one side of a metal lithium foil with the mixedsolution, wherein the coating thickness is 1-150 microns; and 3, drying the surface of the metal lithium foil coated with the mixed solution to form a polymer network for coating the inorganic fillerso as to form a surface protection layer on the surface of the metal lithium foil in situ. The invention aims to inhibit the growth of the metal lithium negative electrode in a battery, and through the polyimide protection layer with high mechanical strength, the metal lithium makes close contact with the protection layer by using an in-situ growth method, so that the interface impedance is reduced, and the coulombic efficiency of the battery is improved; and the ionic conductivity of the protection layer is improved by adding the lithium salt/solid electrolyte, and the rate capability is improved.

The invention relates to a high-voltage polymer electrolyte and a preparation method of a solid-state battery thereof, and the preparation method of the high-voltage polymer electrolyte comprises thefollowing steps: (1) dissolving a polymer in a solvent at normal temperature or by heating at the temperature of 25-120 DEG C; (2) dissolving a certain proportion of lithium salt into the mixture, wherein the mass of the lithium salt accounts for 100%-200% of the mass of the polymer; (3) adding a high-voltage additive into the mixture, uniformly stirring, then pouring the mixture into a membrane or coating the membrane with the mixture, and carrying out blast heating and drying to obtain a high-voltage-resistant composite high-voltage polymer electrolyte membrane, wherein the mass of the high-voltage additive accounts for 1%-10% of the mass of the polymer. The high-voltage polymer electrolyte is prepared by adding the high-voltage-resistant additive, has relatively low interface impedanceand relatively high ionic conductivity, and is beneficial to improving the energy density, the power density and the safety of the solid-state battery.

The invention provides a composite electrolyte. According to the composite electrolyte, the porous solid electrolyte layer is adopted, and the pores of the porous solid electrolyte layer are filled with the gel electrolyte, so that the ionic conductivity is improved, the interface impedance between the electrolyte and the electrode plate is reduced, and the cycle performance and the rate capability of the battery are improved when the composite electrolyte is applied to the battery.

The invention provides a gel type ionic liquid electrolyte for a lithium ion battery as well as a preparation method and application thereof. The method comprises the following steps: adding a Lewis acid type lithium salt initiator; initiating in-situ ring-opening polymerization of a cyclic ether organic solvent at a low temperature to form a three-dimensional cross-linked network polymer; and limiting the ionic liquid, the lithium salt and the like in a three-dimensional polymer structure by taking the polymer as a skeleton structure. Therefore, the in-situ preparation of the gel-type ionic liquid electrolyte is realized, the sufficient contact between the electrolyte and an electrode material as well as a diaphragm is ensured, the interface impedance can be effectively reduced, a Lewis acid type lithium salt initiator and a multi-lithium salt solute form a multi-lithium salt system, and the improvement of the cycle performance and stability of the gel-type ionic liquid electrolyte isfacilitated; besides, the ionic liquid is introduced, so that the thermal stability and the electrochemical window of the electrolyte are improved while the growth of lithium dendrites is remarkablyinhibited, and the safety performance of the electrolyte is effectively improved.

The invention provides a molecular brush polymer film based on a cellulose network structure, and a preparation method and application thereof. According to the three-dimensional network structure, functional macromolecules are grafted on cellulose through a surface grafting technology, and a film is prepared through suction filtration or heating volatilization and serves as a gel polymer electrolyte part in a lithium battery. The network structure is a novel three-dimensional network structure constructed by taking natural polymer cellulose as a skeleton and grafting with a functional molecular brush, so that not only can the liquid absorption rate of the material be obviously improved, but also the moving speed of lithium ions can be effectively improved. In addition, on one hand, the migration number of lithium ions can be obviously increased by grafting a functional molecular brush with a lithium salt group. On the other hand, the functional molecular brush contains alkoxy groups,so that the ionic conductivity of lithium ions can be improved, and the electrochemical performance of the lithium battery is effectively improved. In the process of assembling the battery, an in-situthermal polymerization method is utilized to effectively reduce the interface impedance between the internal electrode of the lithium metal battery and the electrolyte.

The invention relates to nanocomposite gel electrolyte, a lithium secondary battery and a preparation method of the lithium secondary battery. The gel electrolyte is prepared by the steps: introducinghydrophobic modified nanoparticles into liquid electrolyte, and forming a three-dimensional network by using hydrogen-bond interaction among the hydrophobic modified nanoparticles and surface modified molecules thereof and electrolyte solvent molecules, so as to enable gelation of the liquid electrolyte. The ionic conductivity of the gel electrolyte is close to that of electrolyte of the same type and is about 10<-3> S/cm. According to the addition of the hydrophobic modified nanoparticles, the lithium-ion transference number of the electrolyte can be effectively improved, and the interface impedance between the electrolyte and the lithium metal is reduced. In addition, compared with the pure electrolyte of the same type, the gel electrolyte has excellent compatibility with a lithium metal electrode and good cycling stability. The gel electrolyte can be compounded onto the diaphragm in a direct coating or coating swelling method, the preparation process is simple, and convenient production is facilitated.

The invention discloses a lithium ion battery non-aqueous electrolyte and a lithium ion battery, comprising an electrolyte, a non-aqueous organic solvent and an additive, wherein the additive comprises the mixture of a compound A, a compound B, vinylene carbonate and 1,3-propane sultone; the compound A introduces a cyano group based on a phosphate-containing group, and the compound B acts as a high-temperature heat stabilizer. The interaction between the compound A and the compound B effectively reduces the interfacial impedance of the lithium battery, and improves the high temperature and lowtemperature performance of the lithium battery while taking into account the thermal stability of the electrolyte.

The invention discloses a co-sintering method of a positive electrode, an electrolyte and an inorganic lithium salt. The method comprises the following steps: co-sintering a nickel ternary material (NCM), garnet type solid electrolyte (LLZO) powder and inorganic lithium salt (Li3PO4) on the surface of a solid electrolyte sheet, tightly combining the composite positive electrode layer with the solid electrolyte sheet, so that lithium ion transmission is promoted, the interface impedance is reduced, and the charge-discharge capacity and the cycle performance of an all-solid-state lithium battery are improved. Compared with a positive electrode interface treatment process, the preparation method is simple, the cost is low, the interface resistance can be effectively reduced, and the capacityand the cycle performance of the all-solid-state lithium battery are improved. The all-solid-state lithium battery prepared by the invention shows excellent cycle performance in a charging and discharging range of 2.7-4.5 V, and the specific capacity of an electric field is greatly improved.