1483 results about "Lithium dendrite" patented technology

The invention relates to the technical field of solid-state lithium batteries, in particular to a cellulose acetate modified PEO-based solid-state electrolyte membrane, a solid-state lithium battery and a preparation method thereof.The preparation method comprises the steps that lithium bis (trifluoromethanesulfonyl) imide, cellulose acetate and polyethylene oxide are dissolved in a solvent, and a mixed solution is obtained; and curing the mixed solution in a mold to obtain the cellulose acetate modified PEO-based solid electrolyte membrane. According to the invention, the cellulose acetate is introduced to modify the polyethylene oxide solid electrolyte, and the prepared cellulose acetate modified PEO-based solid electrolyte membrane can generate a stable solid electrolyte interface rich in Li2O and LiF on the surface of a lithium negative electrode in situ in the application of a solid lithium battery, so that the growth ability of lithium dendrites is effectively inhibited, and the performance of the lithium battery is improved. The interface impedance is reduced, and the operating temperature range of the solid-state lithium battery is widened.

The invention discloses a lithium ion battery internal short circuit fault detection method based on time-frequency fusion, and the method comprises the steps: firstly constructing a fractional order equivalent circuit model fused with an electrochemical aging mechanism, and simulating the paths of conductivity reduction, active material loss and lithium inventory reduction in combination with an aging empirical formula; joint modeling of the aging process and the random internal short circuit is achieved, and multi-cycle voltage and current and electrochemical impedance spectroscopy data are obtained; secondly, extracting time domain features by using a time domain attention enhanced long-short-term memory network, and analyzing frequency domain information by using a multi-scale frequency sensing convolutional neural network; and then weighting and screening two types of modal features through a dynamic gating fusion module, introducing a cross attention mechanism to establish dependency mapping between time-frequency domain features, and finally outputting an internal short circuit fault detection result. The method can solve the problems that in the lithium ion battery aging process, due to lithium dendrite growth, the internal short circuit early fault is high in concealment, and single time-frequency characteristics are difficult to detect, and early high-precision recognition of the internal short circuit fault can be achieved.

The invention provides a diaphragm and a preparation method thereof and a lithium ion battery, the diaphragm comprises a porous support layer and a gradient functional layer, the porous support layer comprises a base membrane with the porosity of 45-60% and active groups modified on the surface of the base membrane, and the gradient functional layer comprises a heat conduction strengthening layer and an ion channel layer, the heat conduction strengthening layer comprises a first polymer and a modified boron nitride nanosheet, and the ion channel layer comprises a second polymer and a solid electrolyte nanowire. The porous supporting layer and the gradient functional layer are overlapped to form the composite diaphragm, so that high thermal stability, high wettability and high ion conductivity are synergistically realized, and formation of lithium dendrites can be inhibited.

The invention relates to the technical field of lithium battery polymer solid electrolyte materials, and discloses a high-pressure-resistant in-situ polymerization quasi-solid electrolyte membrane as well as a preparation method and application thereof. The preparation method comprises the following steps: carrying out esterification reaction on bacterial cellulose and 2-bromoisobutyryl bromide to obtain bromine-modified bacterial cellulose, grafting a double-block polymer side chain on the surface of the bromine-modified bacterial cellulose to obtain a one-dimensional polymer brush, and preparing a one-dimensional polymer brush film; a one-dimensional polymer brush film is used as a supporting film, an in-situ polymerization precursor solution is dropwise added to the surface of the supporting film, and the high-pressure-resistant in-situ polymerization quasi-solid electrolyte film is obtained through in-situ ring opening polymerization. The prepared high-pressure-resistant in-situ polymerization quasi-solid-state electrolyte membrane has excellent mechanical performance, the thickness of polymer electrolyte can be reduced, and growth of lithium dendrites can be inhibited; the rich pore structure is beneficial to rapid transmission of lithium ions; and the block in the side chain is beneficial to lithium ion transmission and lithium metal uniform deposition, and improves the stability of the electrolyte membrane in a high-voltage environment.

The invention relates to a lithium ion battery thermal runaway early warning method and device and a medium, and the method comprises the steps: setting an AC excitation power supply parameter, and outputting a sine excitation current with a preset frequency and amplitude; injecting the polymer into a single battery through a four-probe method; synchronously acquiring an injection current signal and a response voltage signal; through fast Fourier transform analysis, the amplitude and the phase of a signal fundamental frequency component are extracted; and calculating the electrochemical impedance under the frequency. And in combination with an electrochemical impedance-thermal runaway precursor mapping database established by a pre-experiment, converting the impedance value into a corresponding thermal runaway risk level, and outputting corresponding early warning information. According to the method, lithium dendrite growth and internal micro short circuit signs can be captured in advance, and the early warning time efficiency is remarkably improved compared with traditional voltage / temperature monitoring.

The invention discloses a negative pole piece and a preparation method thereof, a bipolar pole piece and a preparation method thereof, a battery and an electric device. The negative pole piece comprises a first current collector and a second current collector, wherein the first current collector comprises a first side and a second side which are opposite to each other; the first active material layer and the second active material layer are sequentially arranged on the first side in the direction away from the first current collector, the first active material layer comprises metal lithium, and the second active material layer comprises metal lithium alloy. By adopting the negative pole piece or the bipolar pole piece, the problems of continuous thickening of an SEI film, continuous growth of lithium dendrites, lithium death, penetration of the lithium dendrites to a diaphragm and the like can be avoided, so that the cycle stability of a battery applying the negative pole piece or the bipolar pole piece is favorably improved.

The invention discloses a digital twin drive life prolonging system and method in a lithium battery aging process, the system comprises a sensor detection module, an AI control module and a regulation and control module, the sensor detection module detects pressure, temperature, gas components, SEI film conditions and voltage data between a conductive layer and an anode, and inputs the data into the AI control module; the AI control module performs electrochemical-thermodynamic-mechanics multi-physics field coupling modeling by applying a digital twinborn technology, performs data analysis and processing in combination with cross-working-condition model migration, screens out an optimal regulation and control scheme according to a mirage optimization algorithm, sends an instruction to the regulation and control module, and controls the regulation and control module according to the instruction of the AI control module. Parameters in the energy storage cabin are adjusted, the SEI film state is maintained, and lithium dendrite precipitation is controlled, so that the service life of the lithium battery is prolonged; according to the method, the digital twinborn model is utilized to identify battery capacity attenuation inflection points, trigger lithium supplement or charge strategy optimization and other regulation measures, irreversible damage is avoided, and the replacement frequency is reduced.

The invention discloses a high-interface-stability composite solid electrolyte membrane as well as a preparation method and application thereof. The composite solid electrolyte membrane comprises a gradient aperture three-dimensional porous skeleton formed by sintering inorganic solid electrolyte particles, a polymer electrolyte filled in a pore channel, and a plastic interface stable layer positioned between the electrolyte membrane and an electrode. The preparation method comprises the following steps: preparing a gradient aperture porous framework through a pore-forming agent template method and a tape casting technology, dipping and filling a polymer electrolyte precursor solution in a solution, accelerating in-situ polymerization by adopting electric induction, and performing hot-pressing treatment. The composite solid-state electrolyte membrane has high ionic conductivity, excellent interface compatibility and high mechanical strength, can effectively inhibit the growth of lithium dendrites, can be applied to solid-state batteries such as lithium metal batteries, lithium sulfur batteries and lithium air batteries, and can remarkably prolong the cycle life and improve the safety performance of the batteries, and the preparation process is suitable for large-scale production.

The invention provides a modified lithium metal negative electrode and a preparation method and application thereof, and belongs to the technical field of lithium batteries. The modified lithium metal negative electrode comprises a negative electrode conductive substrate and an interface passivation layer formed on the surface of the negative electrode conductive substrate, and the interface passivation layer comprises lithium oxide, lithium sulfide, lithium nitride, lithium fluoride and a fluorocarbon compound; the interface passivation layer is obtained by putting lithium metal into chloroform for dipping treatment to obtain modified lithium metal and then performing plasma treatment. According to the lithium ion battery, the interface passivation film containing the lithium oxide, the lithium sulfide, the lithium nitride, the lithium fluoride and the fluorocarbon is formed on the negative electrode conductive substrate, and in the repeated charging and discharging process of the lithium ion battery, due to the existence of the interface passivation film, non-uniform deposition of lithium ions can be avoided, so that growth of lithium dendrites is inhibited. Furthermore, the coulombic efficiency and the cycling stability of the charge-discharge cycle of the lithium ion battery can be improved, and the service life of the lithium ion battery is prolonged.

The invention belongs to the technical field of lithium ion batteries, and particularly relates to a deep eutectic electrolyte, a preparation method and application thereof and a lithium ion battery. The deep eutectic electrolyte provided by the invention comprises a lithium salt and fluorine-containing amide, the mass ratio of the lithium salt to the fluorine-containing amide is 1: (1-12). According to the deep eutectic electrolyte provided by the invention, the lithium salt and the fluorine-containing amide are compounded, so that the obtained electrolyte can be kept in a liquid state within a relatively wide temperature range; the strong interaction between the fluorine-containing amide and the lithium salt can dissociate a large amount of lithium salt, promote rapid conduction of ions and increase the migration rate of lithium ions in the electrolyte, so that the electrochemical performance of the electrolyte is improved; the fluorine-containing amide molecules and the lithium ions form a solvation effect, and a layer of SEI film rich in LiF and Li3N is formed on the surface of the lithium metal in the circulation process, so that uniform deposition of the lithium ions is promoted, growth of lithium dendrites is inhibited, consumption of electrolyte is reduced, and the circulation stability of the lithium ion battery is further improved.

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 discloses a method for preparing a lithium-copper composite negative electrode by utilizing lithium slag and application, and the preparation method of the negative electrode comprises the following steps: adding the lithium slag with certain concentration after removing impurities such as Ca < 2 + >, Mg < 2 + > and Fe < 3 + > through acid treatment into metal lithium in a molten state, and fully stirring until the reaction is complete; and coating the molten metal lithium obtained after the reaction on a current collector to obtain the modified lithium metal negative electrode plate. The prepared lithium-copper composite negative electrode has a lithium-loving 3D frame structure, volume expansion in the circulation process can be inhibited, lithium oxide, lithium aluminum alloy and lithium silicon alloy existing on the 3D frame structure can serve as lithium-loving sites for uniform lithium ion deposition, lithium dendrite growth is inhibited, and long-term stable circulation of the lithium metal negative electrode is promoted.

The invention provides a fast-charging type solid-state lithium battery alloy negative electrode material, a preparation method and a solid-state lithium battery, and relates to the technical field of lithium batteries. The alloy negative electrode material comprises the following element components in percentage by mass: 30-38% of indium In, 30-35% of tin Sn, 28-35% of bismuth Bi and 0-1.5% of doping elements, crystal phases formed by the alloy negative electrode material of the fast-charging type solid-state lithium battery at least comprise two crystal phases, namely InSn4 and InBi. The alloy negative electrode material has relatively high surface capacity, lithium ion conductivity and lithium ion diffusion coefficient, lithium dendrites do not grow on a negative electrode when a solid-state lithium battery assembled by the alloy negative electrode material is charged and discharged under high current density, and the battery is high in energy density and long in cycle life.

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 provides a preparation method of an in-situ gel electrolyte lithium metal battery based on a PTFE diaphragm, and belongs to the technical field of lithium batteries. Mixing a polymeric monomer, a lithium salt, a solvent and an initiator to obtain a precursor solution; injecting part of the precursor solution into a battery equipped with a positive electrode and a negative electrode, and carrying out preliminary infiltration; a PTFE diaphragm is added, the remaining precursor solution is added, and secondary infiltration is carried out; and placing in a drying oven, standing, and completing in-situ polymerization to obtain the lithium metal battery based on the PTFE diaphragm and the gel electrolyte. The gel electrolyte can effectively reduce the interface resistance and has a certain repulsive effect on FSI <-> in the electrolyte, so that the FSI <-> can reach an interface in advance to be decomposed to form SEI (solid electrolyte interface) which is mainly controlled by anions and is rich in inorganic components, the interface stability is enhanced, and the growth of lithium dendrites can be effectively inhibited.

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.

The invention belongs to the technical field of batteries, and particularly relates to a negative electrode material, a secondary battery and electric equipment. The second coating layer with the porous carbon material in the negative electrode material provides a sufficient buffer space for volume expansion of silicon, so that cracks and pulverization of the negative electrode material are effectively reduced, and the structural integrity of the negative electrode material is further ensured. And meanwhile, the solid electrolyte arranged in the second coating layer can maintain the smoothness of an ion transmission path in the silicon expansion process, so that the rate capability and the quick charge performance of the battery are ensured. Besides, a third coating layer (SEI film) formed by the ionic liquid has good ionic conductivity, and dynamic covalent bonds existing in some ionic liquids can be fractured and recombined under the action of external stress, so that a self-repairing function is realized. Therefore, when cracks are generated on the surface of the negative electrode material due to volume expansion, the third coating layer can quickly repair the cracks, prevent electrolyte permeation and lithium dendrite growth and inhibit side reactions.

The invention relates to the technical field of new energy automobile and battery safety, and discloses a power battery thermal runaway risk early warning method, which comprises the following steps: synchronously acquiring battery internal resistance dynamic change, characteristic gas concentration and temperature gradient distribution through a multi-physics field coupling sensor network, and constructing an electrochemical-thermal-gas ternary early criterion; the internal resistance mutation rate is calculated through self-adaptive sliding window differential, the gas precipitation rate and the temperature space heterogeneity index are combined and input into a multi-branch fusion neural network containing a gating attention mechanism, the continuous thermal runaway risk probability is output, and corresponding early warning is triggered according to grading threshold values. The system comprises an internal resistance, gas and temperature monitoring module and a multi-modal fusion evaluation and grading early warning execution module. According to the method, the traditional early warning logic singly depending on a temperature threshold value is abandoned, a ternary early criterion system with the internal resistance abrupt change rate, the characteristic gas precipitation rate and the temperature space heterogeneity index as the core is constructed for the first time, and electrochemical and physical field anomalies caused by thermal runaway precursor events such as lithium dendrite piercing of a diaphragm and SEI membrane rupture can be effectively captured.

The invention discloses a negative pole piece, a secondary battery and a power utilization device, and belongs to the technical field of batteries, the negative pole piece comprises a negative current collector, and a metal layer and an insulating layer which are sequentially arranged on at least one surface of the negative current collector, and the insulating layer and the metal layer are provided with a plurality of pore structures. The lithium-containing metal layer and the insulating layer are provided with the pore structures, so that the quality and the thickness of the negative electrode plate can be effectively reduced, the energy density of the secondary battery can be effectively improved, pre-lithiation is not needed, a porous conductive substrate is not needed to be introduced, and the lithium-containing metal layer and the insulating layer can be effectively protected. According to the present invention, the negative electrode plate has characteristics of high lithium affinity and high utilization rate of the pore structure, can effectively reduce the volume expansion of the negative electrode plate, provides the sufficient space for the deposition of the lithium, ensures the deposition of the lithium in the pore structure, effectively avoids the occurrence of the internal lithium precipitation and the surface lithium precipitation, reduces the lithium dendrites, and effectively improves the cycle stability of the secondary battery.

The invention relates to the technical field of battery simulation, in particular to a charging and discharging control method and system of a battery simulator. The method comprises the following steps: acquiring ion concentration distribution data of the electrolyte; obtaining diaphragm aperture information; collecting the particle sizes of positive and negative electrode materials in the battery; collecting the initial temperature in the battery; simulating a migration path and a diffusion rate of lithium ions in the electrolyte according to the ion concentration distribution data and the diaphragm aperture information; and predicting the growth trend of the lithium dendrites on the surface of the negative electrode based on the particle sizes of the positive and negative electrode materials and the internal initial temperature of the battery, and evaluating lithium dendrite growth risk data. Through the battery test technology and the battery simulation technology, optimization and dynamic control of the charging and discharging process of the battery are realized, so that the safety, the service life and the performance of the battery are improved.

The invention provides a negative electrode current collector and a preparation method and application thereof, and relates to the technical field of batteries. The negative electrode current collector provided by the invention comprises a metal net and slurry layers coated on two surfaces of the metal net, the slurry layer is mainly composed of a conductive carbon material, metal particles, a sodium-based fast ion conductor or a lithium-based fast ion conductor and a binder; the conductive carbon material is mainly composed of a point type carbon material, a linear carbon material and a surface type carbon material; and the porosity of the slurry layer is 30%-40%. The negative electrode current collector is low in cost, has a porous structure, has sufficient sodium metal or lithium metal deposition space, can enable sodium metal or lithium metal to grow in the negative electrode current collector when being used for a negative-electrode-free electrode, is small in volume change of a battery, and reduces the occurrence of sodium dendrites or lithium dendrites.

The invention provides a composite diaphragm, a preparation method thereof and a lithium ion battery. The composite diaphragm comprises a base diaphragm and a solid electrolyte-water-soluble gel electrolyte composite coating, wherein the surface of the base diaphragm is coated with the solid electrolyte-water-soluble gel electrolyte composite coating by utilizing a roller coating process; the water-soluble gel electrolyte is obtained by co-polymerizing an intermediate I prepared from methyl methacrylate and N-isopropylacrylamide and neopentyl glycol diglycidyl ether. In the composite diaphragm provided by the invention, the water-soluble gel electrolyte can effectively improve the adhesion of the solid electrolyte on the base membrane, and ensure that the solid electrolyte can be effectively adhered to the surface of the base membrane; lithium titanium aluminum phosphate and the like can effectively promote transmission of lithium ions through the solid electrolyte, the hexagonal boron nitride composite coating can prevent direct contact between the lithium titanium aluminum phosphate solid electrolyte and the like and lithium, and the solid electrolyte is protected. And the interface stability of the composite diaphragm is relatively good, and a compact phase formed in the circulation process can effectively inhibit the permeation of lithium dendrites, so that the safety of the battery is improved.

The invention discloses a composite solid electrolyte and a preparation method and application thereof, and belongs to the technical field of solid lithium batteries. The composite solid electrolyte comprises a polymer matrix, a lithium salt and a lithium ion modified ionic metal organic framework (MOF) material. The metal center of the ion-conducting MOF material can be selected from Zr, Ti, Hf and the like, and the organic ligand can be selected from organic acids containing sulfydryl, sulfo groups and the like. The MOF material can effectively inhibit crystallization of a polymer matrix and increase the proportion of an amorphous region, Lewis acid sites on the surface of the MOF material can promote dissociation of lithium salt, and a lithium ion coordination channel formed in the MOF material can provide an extra rapid transmission path for lithium ions. When the electrolyte is applied to the solid-state lithium battery, the growth of lithium dendrites can be effectively inhibited, and the rate capability, the cycling stability and the safety of the battery can be remarkably improved.

The invention provides a composite solid electrolyte layer and a preparation method and application thereof. The composite solid electrolyte layer comprises a lithium dendrite inhibiting layer and a sulfide electrolyte layer at least located on the surface of one side of the lithium dendrite inhibiting layer; the lithium dendrite inhibiting layer comprises a first electrolyte and a second electrolyte; the first electrolyte comprises a sulfide electrolyte; the second electrolyte comprises one or more of an oxide electrolyte, a halide electrolyte and an M-doped electrolyte; m comprises one or more of In, F, I, Sn and Ga. Compared with the prior art, the composite solid electrolyte layer provided by the invention adopts the lithium dendrite inhibiting layer with specific components to be compounded with the sulfide electrolyte layer, so that relatively good overall interaction is realized, the electrolyte membrane can be prevented from being punctured by lithium dendrites, the cycling stability of the battery is improved, separation of a heterogeneous structure is avoided, and the service life of the battery is prolonged. The internal resistance of the battery is lower than that of single-layer electrolyte.

The invention discloses a tantalum-doped lithium metal composite negative electrode and a preparation method thereof. The preparation method comprises the following steps: melting solid-state lithium metal into liquid-state lithium metal; the tantalum metal is added into the liquid lithium metal to be mixed and stirred, the tantalum-doped lithium metal composite material is obtained after standing and cooling, and the adding amount of the tantalum metal is 0.1-10 wt% of the mass of the liquid lithium metal; and rolling the tantalum-doped lithium metal composite material to obtain the tantalum-doped lithium metal composite negative electrode, so that the tantalum is introduced into the lithium metal through a melt doping process, and the formed tantalum-doped lithium metal composite negative electrode can inhibit the growth of lithium dendrites and prolong the cycle life of the battery.

The invention discloses a preparation method of an intrinsically safe polymer electrolyte and a solid-state battery thereof, and belongs to the field of preparation of solid-state lithium metal batteries. The solid polymer electrolyte is of a 1M (xA + yB) + (z1C + z2D) type, x accounts for 14-15 wt%, y accounts for 1-2 wt%, z1 accounts for 70-72 wt%, z2 accounts for 11-12 wt%, A and B are lithium salts, C is a fluorine-containing monomer, D is a cross-linking agent, the fluorine-rich monomer, the cross-linking agent and the lithium salts are mixed, no electrolyte is added, an in-situ thermal polymerization method is adopted to prepare the intrinsic safe solid polymer electrolyte with high safety and high voltage resistance, and meanwhile, the electrolyte is of a three-dimensional chain network structure. Therefore, the safety performance of the electrolyte is effectively enhanced, the migration activation energy of lithium ions is reduced, and the ionic conductivity is improved. The core problems that an existing traditional battery is poor in safety performance, poor in high-voltage tolerance, large in interface impedance, out-of-control in lithium dendrite growth and the like are solved.

The invention discloses a preparation method and application of a composite PVDF-HFP and polylysine nanofiber diaphragm, and belongs to the technical field of lithium batteries. The composite material is prepared by blending polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) and polylysine and then carrying out an electrostatic spinning process. The PVDF-HFP is utilized to provide excellent mechanical strength and chemical stability, rich polar amino functional groups in a polylysine molecular chain are utilized to improve the lyophilic property of the membrane, and anions in an electrolyte are fixed through an intermolecular acting force, so that the transference number of lithium ions is increased, and the lithium ions are induced to be uniformly deposited. The nanofiber membrane combines the characteristics of PVDF-HFP and polylysine, has high porosity, good thermal stability and excellent interface compatibility, can effectively inhibit the growth of lithium dendrites and prevent the diaphragm from being punctured, and can significantly prolong the cycle life and improve the safety performance of the lithium metal battery when being applied to the lithium metal battery.

The invention discloses a lithium-oxygen battery electrolyte and a preparation method and application thereof. The lithium-oxygen battery electrolyte comprises a lithium salt, an additive and a solvent, the additive is 1, 3-dimethylimidazole iodized salt. The redox medium (organic iodized salt) is added into the ether electrolyte of the lithium oxygen battery, anions of the redox medium can reduce the charge-discharge overpotential of the lithium oxygen battery, cations of the redox medium can form an in-situ protection layer on a lithium negative electrode, the redox medium is prevented from reacting with the lithium negative electrode, lithium corrosion and lithium dendrite growth are effectively inhibited, and the service life of the lithium oxygen battery is prolonged. And the lithium-oxygen battery has excellent electrochemical performance and long cycle stability.

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 relates to the technical field of lithium ion batteries, in particular to a preparation method of a lithium negative electrode with an ion / electron mixed conductor framework and application of the lithium negative electrode in the lithium ion battery. In order to solve the problems of lithium dendrite growth, volume expansion, corrosion and the like of the existing lithium negative electrode material in the battery cycle process, the invention provides an innovative solution that a double-fiber network skeleton consisting of a LiB compound and VGCF is constructed through a mechanical rolling method and a processing regulation and control process so as to enhance the electrode structure stability and inhibit the generation of lithium dendrites. The rate efficiency, the cycle life and the mechanical property of the prepared lithium negative electrode material are evaluated through a symmetric battery test, microstructure and electrochemical property analysis is carried out through TEM, SEM, XRD and other means, and the lithium negative electrode material has excellent comprehensive mechanical property, can inhibit volume expansion, simplifies the processing flow, and is suitable for large-scale production. And the method is suitable for commercial production of new energy batteries. By implementing the invention, the development of a lithium ion battery technology is expected to be promoted, and the requirements of modern society on an efficient and safe energy storage system are met.