229 results about "Lithium ion conduction" patented technology

The invention belongs to the technical field of battery material preparation, and particularly relates to a coated negative electrode material as well as a preparation method and application thereof. The coated negative electrode material comprises a porous carbon skeleton and a carbon coating layer coating the porous carbon skeleton, the porous carbon skeleton is provided with a plurality of holes; a silicon layer and a functional layer are attached to the surfaces of part of the holes; the silicon layer comprises silicon, the functional layer comprises a functional material, and the functional material comprises lithium aluminum fluoride. The coated negative electrode material provided by the invention has the properties of low expansion, high lithium ion conduction, few byproducts and the like, and is suitable for a solid battery; the battery energy density is ensured, and the problems that an effective lithium ion path cannot be formed due to contact failure of an active substance caused by high volume expansion of a silicon-based material in the circulation process and contact failure of the active material and a solid electrolyte in a solid-state battery, and performance degradation is caused by negative electrode side polarization increase in the circulation process are solved.

The invention relates to the technical field of batteries, in particular to a porous composite diaphragm, a preparation method thereof and a secondary battery. The porous composite diaphragm comprises a base membrane, a first coating and a second coating, the first coating and the second coating are oppositely arranged on the two surfaces of the base film; the first coating layer and the second coating layer comprise a copolymer containing a first monomer unit and a second monomer unit; the first monomer unit contains a cyano group on a side chain, and the second monomer unit contains a carbonyl group on a side chain; in the copolymer, the molar ratio of the second monomer unit is 1-20%; the first coating and the second coating comprise skeleton structures and first-class pore structures formed between the skeleton structures, and second-class pore structures are formed on bodies of the skeleton structures; and the average pore diameter of the first-type pore structure is greater than that of the second-type pore structure. According to the porous composite diaphragm, the lithium ion conductivity can be improved while the bonding performance with a pole piece is improved.

The invention provides a composite negative electrode, a preparation method thereof and an all-solid-state lithium battery, and belongs to the technical field of all-solid-state lithium ion batteries. The composite negative electrode provided by the invention comprises a negative electrode material and a nano silicon coating arranged on the surface of the negative electrode material, and the negative electrode material is one or more of Al, Sn, Ge, In, Mg and Ag. The negative electrode material in the composite negative electrode provided by the invention can avoid serious side reaction between the negative electrode and a sulfide solid electrolyte interface, reduce the risk of lithium dendrites at the interface, and ensure the electrochemical performance of the all-solid-state lithium battery; the nano-silicon coating forms a Li-Si alloy layer after the first lithiation, and has high lithium ion conduction characteristic and lower Young modulus, so that good interface contact is formed between the composite negative electrode and a solid electrolyte, a high-diffusivity transmission channel and stable dynamic guarantee are provided for the reversible lithiation / lithium removal process of the composite negative electrode, and the composite negative electrode can be applied to the lithium ion battery. And the electrochemical performance of the all-solid-state lithium battery is further improved.

This lithium recovery device 10C is provided with a processing tank 1 that is partitioned into a supply tank 11 and a recovery tank 13 by a lithium ion-conducting electrolyte membrane 2. In order to selectively move Li+ to an aqueous solution RS in the recovery tank 13 from an aqueous solution SW in the supply tank 11, the aqueous solution SW containing Li+ and other metal ions Mn+, this lithium recovery device 10C is also provided with: a first power supply 51 which is connected between a first electrode 31 that has a porous structure and is arranged so as to be in contact with a supply tank 11-side surface of the electrolyte membrane 2 and a second electrode 32A that is arranged within the recovery tank 13, in such a manner that the first electrode 31 functions as the positive electrode; and a sub power supply 53 which is connected in series to the positive electrode of the first power supply 51, while having the positive electrode thereof connected to a sub electrode 41 that is arranged within the supply tank 11 at a distance from the electrolyte membrane 2.

A separator of a lithium-ion battery cell includes a porous separator film, an inner layer disposed against the separator film and including ceramic filler, and an outer layer disposed against the inner layer and including ferroelectric material configured to facilitate lithium-ionic conductivity between the separator and an electrode.

The invention provides a preparation method and application of a high-nickel ternary positive electrode material flexibly coated with a polymer, and aims to improve the cycling stability and interface compatibility of a battery. According to the technology, a liquid phase method is adopted for preparation, and a uniform and stable coating layer is formed on the surface of the high-nickel positive electrode material, so that the interface characteristic between the positive electrode and sulfide solid electrolyte is effectively improved. The coating layer is formed by compounding a polymer and a lithium salt, and has both electronic insulativity and excellent ionic conductivity. On one hand, the coating layer can prevent electron leakage, inhibit side reaction of a positive electrode-electrolyte interface and improve the interface stability; and on the other hand, the excellent lithium ion conductivity can reduce the interface impedance, accelerate the diffusion of lithium ions, improve the rate capability of the battery and prolong the long-term cycle life of the battery. Besides, by optimizing the components and the thickness of the coating layer and the interface structure of the coating layer and the electrode material, the performance of the battery is improved, and meanwhile, good process feasibility and cost effectiveness are ensured.

The invention relates to a lithium ion conductive dense membrane and a preparation method and application thereof. The lithium ion conductive dense membrane comprises a polymer base membrane, ion conductive inorganic particles and a polymer solid electrolyte, the polymer base membrane is of a net structure; the Gurley value of the lithium ion conductive dense film is larger than or equal to 1000, and the porosity is smaller than or equal to 5%. The lithium ion conductive dense membrane provided by the invention has the advantages of high lithium ion conductivity, high transport efficiency and high lithium ion selectivity, and can be applied to electrodialysis lithium extraction. And under the action of external voltage, lithium ions are directionally migrated to the air negative electrode subjected to oxygen reduction reaction through the lithium ion conductive dense membrane to form a lithium hydroxide solution, and other metal hetero-ions are isolated on the positive electrode side by the lithium ion conductive dense membrane, so that lithium enrichment is realized. And meanwhile, transportation of the membrane to lithium ions does not depend on pores in the conductive membrane, so that the service life can be prolonged while the lithium ion separability and the transportation efficiency of the salt lake lithium extraction method are improved.

The invention relates to the technical field of batteries, in particular to a high-temperature-resistant lithium cobalt oxide positive electrode material and a preparation method and application thereof.The high-temperature-resistant lithium cobalt oxide positive electrode material comprises a lithium cobalt oxide matrix and a coating layer coating the surface of the lithium cobalt oxide matrix, the lithium cobalt oxide matrix is doped with Mg, Ti and La, and the coating layer is a fast ion coating layer of a Li-Gd-Ti-O4 spinel phase. Bulk phase doping is carried out through a high-temperature solid-phase method, Mg, Ti and La are doped in a lithium cobalt oxide matrix, and the lattice structure thermal stability of lithium cobalt oxide under high voltage (4.4 V) is improved; a fast ion coating layer of a Li-Gd-Ti-O4 spinel phase is formed on the surface of a lithium cobalt oxide matrix by adopting a solid phase method, and the comprehensive performance of the lithium cobalt oxide positive electrode material is improved through multiple mechanisms such as the lattice stabilization effect of rare earth ions, the interface barrier effect of composite oxide and lithium ion conductivity regulation and control; particularly, the capacity, the cycling stability, the thermal stability, the high-voltage tolerance and the like are realized.

A lithium recovery device includes a processing tank partitioned into an acid recovery chamber, a lithium supply chamber, an alkali recovery chamber, a lithium recovery chamber in this order, the lithium recovery chamber and the alkali recovery chamber separated by a lithium ion-conductive electrolyte membrane, the acid recovery chamber, the lithium supply chamber, and the alkali recovery chamber separated by ion exchange membranes, and includes power supplies between electrodes provided in each of the alkali recovery chamber and the lithium recovery chamber, and between the electrodes provided in each of the acid recovery chamber and the alkali recovery chamber respectively, with their lithium recovery chamber sides set negative, in order to migrate Li+ selectively from an aqueous solution in the lithium supply chamber containing Li+, other metal ions, and anions such as SO42− to an aqueous solution in the lithium recovery chamber.

The invention provides a non-aqueous electrolyte and a lithium ion battery containing the same, and belongs to the technical field of lithium ion batteries. The non-aqueous electrolyte comprises electrolyte salt, an organic solvent, a nitrile additive and a compound A; complementary construction of an interfacial film is achieved through the synergistic effect of the nitrile additive and fluorosilane, and decomposition of an electrolyte and corrosion of an electrode material are prevented; a lithium ion conduction path is optimized, and the charging and discharging efficiency of the battery in a high-temperature and high-pressure circulation process is improved; transition metal ion migration is inhibited, and the cycle performance at high temperature and high pressure is improved; gas and by-products generated by thermal decomposition are reduced, so that the volume expansion rate of the battery at high temperature and high pressure is reduced, and stable performance of the battery in a high-temperature cycle process is ensured; the volume expansion rate under high-temperature storage is reduced; and the capacity recovery rate is improved.

The invention provides a non-aqueous electrolyte and a lithium ion battery. The non-aqueous electrolyte comprises a lithium salt, a non-aqueous organic solvent and an additive. The additive comprises a compound A as shown in a structural formula I; wherein R1 and R2 are respectively and independently selected from oxygen, sulfur or NR5, R3 and R4 are respectively and independently selected from NR6R7, R5 is C1-C5 alkyl silicon group, and R6 and R7 are respectively and independently selected from C1-C5 alkyl silicon group, C1-C5 alkyl group, substituted C1-C5 alkyl group, phenyl or substituted phenyl. The compound A comprises a cyclic (oxygen, sulfur and nitrogen) phosphamide structure and a trimethylsilyl structure, the trimethylsilyl structure can remove moisture in the electrolyte, and the cyclic (oxygen, sulfur and nitrogen) phosphamide structure is reduced on a negative electrode interface to form a polar solid electrolyte interface film of lithium salt containing oxygen or sulfur and phosphorus and nitrogen; the interfacial film has good lithium ion conductivity and toughness, the charge transfer resistance of the lithium ion battery is reduced, desolvation of lithium ions is promoted, and the high-rate cycle performance of the lithium ion battery is improved. The structural formula I of the # imgabs0 # is shown in the specification.

Batteries, component structures and manufacturing methods, in particular including a glassy embedded battery electrode assembly having a composite material structure composed of interpenetrating material components including a porous electroactive network including a solid electroactive material, and a continuous glassy medium including a Li ion conducting sulfide glass, can achieve enhanced power output, reduced charging time and / or improved cycle life.

The application discloses a modified polyvinylidene fluoride lithium-sulfur battery positive electrode binder and a preparation method thereof, and belongs to the technical field of lithium-sulfur batteries. In the method, a modifier is connected to a polyvinylidene fluoride molecular chain through hydrogen bonds, cross-linking of the polyvinylidene fluoride molecular chain is realized, and the mechanical property of the polyvinylidene fluoride binder is improved. The introduction of the modifier reduces the crystallinity of the polyvinylidene fluoride, increases the porosity, promotes the swelling of the polyvinylidene fluoride binder in electrolyte, and increases the lithium ion conductivity. Meanwhile, the metallocycle connected to the iron atom in the modifier not only provides an adsorption site for lithium polysulfide, but also promotes the conversion of the lithium polysulfide. The modified polyvinylidene fluoride binder obtained by the method has the advantages of simple synthesis process and low cost, can significantly reduce sulfur positive electrode polarization when applied in a lithium-sulfur battery positive electrode, improves the cycle stability and rate performance of the battery, is suitable for traditional lithium battery electrode preparation processes, and is suitable for large-scale commercial application.

A lithium secondary battery including a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and a nonaqueous electrolyte having lithium-ion conductivity. At the negative electrode, lithium metal deposits during charging, and the lithium metal dissolves during discharging. The negative electrode has a porous resin substrate, and a lithium metal layer laminated with the porous resin substrate. The porous resin substrate has a porous region in which the lithium metal layer is not packed.

Solid state batteries having a solid polymer electrolyte (SPE) that replaces a liquid electrolyte between the negative and positive electrode. The SPE is the reaction product of a one-pot polymerization involving a polymer backbone, a Li salt, a plasticizer, and electrolyte additive(s). The electrolyte additive may resolve the anode / electrolyte interfacial corrosive reaction issues to prevent shorting. The negative electrode may be plated with the SPE in the form of an interphase film, which also acts to separate the negative electrode from the positive electrode.

The invention discloses a surface modification method of a high-nickel ternary positive electrode material, relates to a surface in-situ coating technology based on a fast ion conductor, and aims to solve the key problems of interface failure and structure recession in a high-nickel material circulation process. According to the method, a functionalized interface layer with a three-dimensional lithium ion conduction network is constructed on the surface of a positive electrode through a nanoscale in-situ coating technology, and the method is characterized in that a fast ion conductor material is adopted as a coating medium, and interface lithium ion transmission kinetics is remarkably improved by means of the high lithium ion diffusion coefficient of the fast ion conductor material; a continuous coating layer with controllable thickness is formed through a sol-gel method preparation process, and the lithium ion superconducting characteristic is realized while the electron tunneling effect is maintained; the composite structure layer has both a physical barrier function and a mechanical buffer function, and can effectively inhibit electrolyte interface side reaction and particle crack propagation induced by electrochemical cycle stress strain.

The present invention provides a lithium ion battery electrolyte, including an organic solvent, a lithium salt and an additive; the additive includes a first additive and a second additive; the first additive includes tris (2-cyanoethyl) phosphite; the second additive includes a fluorine-containing lithium phosphate salt compound; the fluorine-containing lithium phosphate salt compound has a structure as shown in formula (I). The present invention is creative using tris (2-cyanoethyl) phosphite as the first electrolyte additive and using a fluorine-containing lithium phosphate salt compound as the second additive; the two additives are used together, cooperate with each other, and act synergistically to generate inorganic lithium salt components such as "LiF" and "Li3PO4", and functional groups such as "P-O" and "-CN", which can suppress the precipitation of transition metal ions and the decomposition of the electrolyte, promote lithium ion conduction, thereby improving the comprehensive performance of the battery such as high voltage performance, high temperature performance and cycle performance.

The present invention provides a method for producing a sulfide solid electrolyte capable of continuously and stably producing a sulfide solid electrolyte exhibiting high lithium-ion conductivity. The present invention relates to a method for producing a sulfide solid electrolyte, the method comprising: preparing a sulfide solid electrolyte raw material based on stoichiometric ratio; supplying 0.1-20 mass% of a sulfur source relative to the total amount of the sulfide solid electrolyte raw material; heating and melting the sulfide solid electrolyte raw material; and cooling the obtained melt by contact with a cooling structure. The present invention also relates to a method for producing a sulfide solid electrolyte, the method comprising: preparing a sulfide solid electrolyte raw material based on stoichiometric ratio; heating and melting the sulfide solid electrolyte raw material; cooling the obtained melt by contact with a cooling structure; and obtaining a sulfide solid electrolyte in which the excess proportion of sulfur compared to the stoichiometric composition is 0.0-5.0 mass%.

A negative electrode active material for a secondary battery includes a silicon-containing material. The silicon-containing material includes a lithium-ion conductive phase, silicon particles dispersed in the lithium-ion conductive phase, and particles containing vanadium dispersed in the lithium-ion conductive phase.

A lithium secondary battery is provided with a wound electrode group, a hollow core member disposed in the electrode group, and a non-aqueous electrolyte having lithium ion conductivity. The wound electrode group has a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode. In the negative electrode, lithium metal is precipitated during charging, and the lithium metal is dissolved during discharging. The core member has a hollow cylindrical shape and has a slit extending in the axial direction, and both end portions in the circumferential direction of the slit are offset and do not abut against each other.

The invention discloses a high-flux interface modification method of an oxide-based all-solid-state battery and a lithium ion battery, and belongs to the technical field of solid-state lithium ion batteries. The method comprises the following steps: mixing LTFSI, PVDF-HFP, m-fluorobenzamide and LLZO powder, and adding dimethylformamide to obtain a mixed raw material; adding an organic wet grinding solvent into the mixed raw material, and carrying out ball milling to obtain interface modification slurry; and coating one side of an LLZO electrolyte sheet with the interface modification slurry, and drying to complete interface modification. According to the interface modification method disclosed by the invention, the solid electrolyte has a lithium-loving property, can be in good contact with a metal lithium negative electrode, and can generate LiFamp through an in-situ reaction; and Li3N fills up interface defects and pores, and meanwhile, lithium dendrite growth and electron permeation can be inhibited, so that the interface structure of the obtained modified layer is stable. In addition, the lithium ion conductivity at the interface is further improved, the lithium ion flux at the interface is enhanced, the cycle life of the lithium battery is prolonged, and the preparation method is simple and suitable for industrial large-scale production.

A secondary battery comprises a positive electrode layer (14), a negative electrode layer (12), and an electrolyte layer (15) for conducting lithium ions between the positive and negative electrode layers. The positive electrode layer contains a positive electrode active material (14a) containing Mn and an oxide-based ion conductor (14b) with lithium ion conductivity. The electrolyte layer contains a fluorinated lithium salt containing fluorine atoms and a solvent capable of dissolving the fluorinated lithium salt. The ion conductor is a dielectric that promotes the dissociation of lithium ions from the fluorinated lithium salt.

Provided is a lithium metal secondary battery having a novel structure in which an intermediate layer is provided between a negative electrode layer and a solid electrolyte layer, lithium metal can be uniformly deposited on the intermediate layer-side surface of the negative electrode layer, and dendrites are not easily generated. This lithium metal secondary battery is provided with a positive electrode layer, a negative electrode layer, a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer, and an intermediate layer disposed between the negative electrode layer and the solid electrolyte layer, and is characterized in that: a lithium metal layer is disposed on the surface of the negative electrode layer on the intermediate layer side; and an intermediate layer insulating material that covers the outer peripheral surface of the intermediate layer, the intermediate layer insulating material not having lithium ion conductivity.

To provide a composite positive electrode active material capable of reducing the resistance of a battery.SOLUTION: A composite positive electrode active material has a positive electrode active material and a lithium ion conductive oxide containing at least one of B element and P element on at least a part of the surface of the positive electrode active material. The composite positive electrode active material has a solid electrolyte on at least a part of the surface of the lithium ion conductive oxide. The interface length value A (μm-1) obtained by dividing the length (μm) of the interface between the positive electrode active material and the solid electrolyte confirmed from a SEM image of a cross-section of the composite positive electrode active material by the area (μm2) of the positive electrode active material in the SEM image is 1.326 or more.SELECTED DRAWING: Figure 1

The invention discloses a graphite negative electrode material and a preparation method thereof, a pole piece and an electrochemical device. The preparation method of the graphite negative electrode material comprises the following steps: performing heat treatment on a raw material mixture comprising graphite, an indium source and a solvent, thereby obtaining the graphite negative electrode material, wherein the mass ratio of the indium source to the graphite is 0.2%-2%; the indium source is an indium-containing compound; the temperature of the heat treatment is 200-1000 DEG C. The graphite negative electrode material comprises a graphite base material and a coating layer coating the surface of the graphite base material, and the coating layer comprises an indium element. When the graphite negative electrode material is actually applied to an electrochemical device such as a lithium battery, the lithium ion conductivity can be effectively improved, meanwhile, the stability of a formed SEI film is effectively improved, and finally, the comprehensive electrochemical performance such as the first coulombic efficiency, the cycle and storage stability and the like of the obtained lithium battery is integrally improved.

The application discloses a high lithium ion conductivity flame-retardant interface modifier and a preparation method thereof. The material is synthesized by one-pot one-step reaction of phosphorus oxychloride, diamine and alcohol ether compound, and is used in combination with lithium salt to form a flame-retardant interface modifier with high lithium ion conduction function. The molecular structure is rich in ether bonds, which can effectively coordinate with lithium ions, promote the efficient migration of lithium ions at the electrode interface, and significantly improve the cycle stability and rate performance of the solid-state battery. At the same time, the nitrogen and phosphorus elements introduced in the material endow it with excellent flame-retardant properties, which helps to improve the safety of the battery system. In addition, the modifier has good flowability and wettability, which can enhance the interface compatibility between the components in the solid-state battery. The preparation process of the application is simple, controllable, reproducible and low in cost, and is suitable for interface modification of solid-state lithium ion batteries, and has important prospects for promoting the development of high-safety, high-energy-density and low-cost solid-state batteries.

The invention discloses a method for removing Li2CO3 on the surface of an LLZO type electrolyte and a preparation method of a composite electrolyte membrane. The method comprises the following steps: S1, preparing a trifluoromethanesulfonate solution; s2, dispersing LLZO powder of which the surface is coated with Li2CO3 into the prepared trifluoromethanesulfonate solution, and carrying out normal-temperature ultrasonic treatment; s3, adding a lithium salt with a corresponding proportion into the solution, and standing at room temperature for 24 hours to form a precursor solution A; and S4, taking a certain amount of the precursor solution A, dropwise adding the precursor solution A to two sides of the diaphragm, and continuously standing at room temperature for 24 hours until the precursor solution A is completely polymerized to form the organic-inorganic composite solid electrolyte membrane. The used trifluoromethanesulfonate can improve the lithium ion conduction performance of the composite electrolyte membrane while performing affinity treatment on Li2CO3 on the surface of LLZO, optimizes lithium deposition, and reduces the growth of lithium dendrites; meanwhile, trifluoromethanesulfonate is used as an initiator for ring-opening polymerization of a precursor solution, and the composite electrolyte is subjected to in-situ polymerization in the battery, so that the interface impedance of the battery is reduced, and the operation stability of the LLZO-based organic-inorganic composite solid electrolyte is ensured.

The application relates to the technical field of lithium batteries, and particularly discloses a metal lithium alloy negative electrode material and a preparation method thereof. The negative electrode material comprises a three-dimensional porous alloy framework, a porous carbon layer compounded on the surface of the three-dimensional porous alloy framework, and metal lithium at least partially filled in the pores of the three-dimensional porous alloy framework; wherein the three-dimensional porous alloy framework is a porous structure formed by metal lithium and alloy metal, and a fast ion conduction phase LiC6 is formed at the interface between the porous carbon layer and the three-dimensional porous alloy framework; and the preparation method comprises the steps of smelting, ultrasonic treatment, casting forming, rolling into a strip, corona surface treatment, composite rolling, porous carbon compounding, secondary rolling, heat treatment and the like. By constructing the three-dimensional alloy framework with the super-ion conductor characteristics and the LiC6 fast ion conduction interface layer, the lithium dendrite growth is effectively inhibited, the volume expansion is buffered, and the lithium ion conduction rate and the cycle stability are improved.

This invention provides a lithium-sulfur silver-germanium ore-based multiphase solid-state electrolyte material, its preparation method, and its application, relating to the field of solid-state battery technology. The multiphase solid-state electrolyte material comprises a metal / oxygen co-doped lithium-sulfur silver-germanium ore phase as a matrix, with heterogeneous disulfide nanoparticles dispersed at the grain boundaries of this matrix. This invention utilizes a lithium-sulfur silver-germanium ore-type solid-state electrolyte with high ionic conductivity as the matrix material and introduces high-valence metals and oxygen elements for co-doping, promoting the formation of sulfur vacancies and reducing the lithium-ion diffusion barrier. Simultaneously, the interfacial effect of the heterogeneous disulfide nanoparticles at the grain boundaries helps reduce the internal interfacial resistance of the electrolyte, further improving lithium-ion conduction efficiency. Furthermore, the high electronegativity of the high-valence metals and oxygen elements, along with the in-situ passivation effect of the heterogeneous disulfide, significantly enhances the stability of the electrolyte under high-voltage conditions, reduces side reactions between the electrolyte and the cathode material, and improves the overall cycle performance of the battery.

The invention relates to a binder, slurry, a lithium battery positive electrode and a lithium battery, the binder comprises a first polymer, a second polymer, a third polymer and a fourth polymer, the first polymer is selected from at least one of polyvinylidene fluoride-hexafluoropropylene, polyvinyl alcohol, polyvinylidene fluoride, polyacrylonitrile, polycarbonate and polyacrylic acid, and the second polymer is selected from at least one of polyvinylidene fluoride-hexafluoropropylene, polyvinyl alcohol, polyvinylidene fluoride, polyacrylonitrile, polycarbonate and polyacrylic acid. The second polymer is selected from at least one of sulfonated polyetheretherketone, sulfonated polyethersulfone, sulfonated polyetheretherketone, sulfonated polyetheretherketone lithium, sulfonated polyethersulfone lithium and sulfonated polyetheretherketone lithium, the third polymer is a conductive polymer, and the fourth polymer is a copolymer of ethylene and acrylic acid. The binder disclosed by the invention has relatively good lithium ion conduction effect, electron conduction effect and binding performance.