1807 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 relates to the technical field of functional materials, in particular to a hollow multi-shell material as well as a low-temperature preparation method and application thereof, which comprises the following steps: 1) mixing a water or alcohol solution of a precursor A with an oil phase to prepare a water-in-oil emulsion, or dispersing the water solution of the precursor A into liquid drops by a spraying method; 2) freezing the emulsion or liquid drops obtained in the step 1) at low temperature to obtain ice template particles containing a precursor A; (3) adding the ice template particles obtained in the step (2) into a precursor B solution, controlling the temperature by a program, melting the ice template, and carrying out precipitation or polymerization reaction on A and B to obtain metal fluoride, carbonate or other hollow multi-shell materials; and 4) using the hollow multi-shell layer obtained in the step 3) as an electrolyte additive. The electrolyte additive can improve the viscosity of an electrolyte, improve the ionic conductivity, stabilize a solid electrolyte interface film, effectively inhibit the growth of lithium dendrites, improve the coulombic efficiency of a battery and prolong the cycle life of the battery.

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 three-dimensional network polymer gel electrolyte, a positive plate and a solid-state lithium battery. The three-dimensional network polymer gel electrolyte comprises 80-98% of an organic solvent, 5-15% of a lithium salt, 2-8% of lignosulfonate, 2-10% of a polymeric monomer and 2-8% of an ionic liquid, and the polymeric monomer is selected from acrylamide, polyethylene glycol dimethacrylate, 3-(methacryloyloxy) propyl trimethoxy silane or tetrahydrofurfuryl acrylate and the like. Under ultraviolet light, lignosulfonate can spontaneously generate quinonyl photochemical free radicals and hydroxyl photochemical free radicals in a mixed solution of ionic liquid and specific polymer monomers, and under the action of the photochemical free radicals, the lignosulfonate reacts with unsaturated double bonds on a polymer through phenolic groups, so that the photochemical free radicals are formed. The gel electrolyte with a three-dimensional network structure is formed, the mechanical strength can be improved, the growth of lithium dendrites in a lithium metal battery can be inhibited, and the metal lithium battery containing the gel electrolyte has excellent cycle life and safety performance.

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.

A lithium ion-conductive solid electrolyte including a freestanding inorganic vitreous sheet of sulfide-based lithium ion conducting glass is capable of high performance in a lithium metal battery by providing a high degree of lithium ion conductivity while being highly resistant to the initiation and / or propagation of lithium dendrites. Such an electrolyte is also itself manufacturable, and readily adaptable for battery cell and cell component manufacture, in a cost-effective, scalable manner. An automated machine based system, apparatus and methods assessing and inspecting the quality of such vitreous solid electrolyte sheets, electrode sub-assemblies and lithium electrode assemblies can be based on spectrophotometry and can be performed inline with fabricating the sheet or web (e.g., inline with drawing of the vitreous Li ion conducting glass) and / or with the manufacturing of associated electrode sub-assemblies and lithium electrode assemblies and battery cells.

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 provides an ionic liquid additive for a solid-state lithium metal battery electrolyte and a method for preparing the solid-state lithium metal battery electrolyte by using the ionic liquid additive. The bistrifluoromethanesulfonyl imide salt containing terphenyl and lithium carboxylate obtained through Michael addition reaction is captured by open metal sites of the MOF material UiO-66-NH2, the structural stability of the material can be improved, more transmission channels are provided for lithium ions, and therefore the transference number of the lithium ions is increased, the performance of the lithium metal battery is improved, and the service life of the lithium metal battery is prolonged. Especially in the aspect of charge and discharge rate. The electrolyte material disclosed by the invention has good stability with lithium metal, so that electrolyte decomposition can be prevented, and an unstable phenomenon, such as lithium dendrite growth, on the surface of an electrode can be avoided, so that a lithium metal battery can show excellent electrochemical performance, including better cycling stability, high coulombic efficiency and longer battery life.

The invention discloses a modified lithium borohydride solid electrolyte and a preparation method thereof, and belongs to the field of all-solid-state battery electrolyte preparation, the method comprises the following steps: mixing LiBH4 and lithium halide according to a formula ratio, and carrying out ball milling and heating to obtain an xLiBH4-LiX (x = 1-5) solid solution; then mixing and ball-milling B2O3 and the LiBH4-lithium halide solid solution to obtain a doped and composite synergistically modified (xLiBH4-LiX) y-B2O3 (y is equal to 10 to 20) solid electrolyte; a LiBH4 phase is stabilized by doping lithium halide, and grain gaps are densified by compounding B2O3, so that the grain boundary impedance is reduced, the lithium dendrite inhibition capability of the lithium borohydride-based solid electrolyte is improved, the stable operation of the lithium borohydride-based solid electrolyte at high voltage is ensured, and the lithium borohydride-based solid electrolyte has relatively high ionic conductivity, relatively low electronic conductivity and a relatively wide electrochemical window; and the lithium borohydride-based solid electrolyte has good stability and compatibility with a lithium metal negative electrode, and development of the lithium borohydride-based solid electrolyte in commercial application of a lithium ion battery is facilitated.

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 discloses a preparation method of a lithium metal negative electrode with an ultrathin lithium-loving high-entropy alloy interface layer, and belongs to the technical field of lithium metal batteries. The preparation method comprises the following steps: dispersing a carbon nanotube coated high-entropy alloy composite material, lithium tin alloy powder and a hydrophobic polymer in a non-organic solvent, coating a copper foil with the mixture, and drying the copper foil to obtain an ultrathin, pre-lithiated and lithium-loving negative electrode of a high-entropy alloy interface layer. According to the preparation method of the lithium metal negative electrode with the ultrathin lithium-loving high-entropy alloy interface layer, catalytic elements in the high-entropy alloy composite material coated with the carbon nanotubes are used for inducing the carbon nanotubes to form a 3D conductive network framework, so that the current density of the electrode can be effectively reduced, lithium metal deposition can be accommodated, and the lithium metal negative electrode has a good application prospect. And meanwhile, release of lithium ions in the lithium tin alloy can be activated for lithium pre-supplement, so that generation of lithium dendrites and dead lithium is inhibited, the volume change of a lithium metal negative electrode in the charge-discharge cycle process is slowed down, and the cycle stability of the battery is improved.

The invention provides a non-Newtonian fluid quasi-solid electrolyte, a preparation method and application, the electrolyte is prepared from the following raw materials: a basic electrolyte, a shear thickening raw material, a polymeric monomer, a cross-linking agent and a thermal initiator, and the mass ratio of the basic electrolyte to the shear thickening raw material is 20: (1-10). The quasi-solid electrolyte with the non-Newtonian fluid characteristic is used for absorbing stress caused by lithium plating / lithium removal of the battery, the volume change of the battery in the charging and discharging process is relieved, mechanical hardening is rapidly generated when the battery is subjected to large-current pulse charging or external sudden bearing, the growth of lithium dendrites is inhibited, and internal short circuit is prevented; a polymer network obtained by carrying out in-situ polymerization on a polymeric monomer, a cross-linking agent, a thermal initiator and the like is adopted, so that battery liquid leakage or oxygenolysis is prevented, metal lithium is deposited and dissolved more uniformly, and the growth of metal lithium dendrites is inhibited; through the synergistic effect of the non-Newtonian fluid and the in-situ polymerized polymer network, the safety performance and the cycle performance of the battery can be remarkably improved.

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 provides a preparation method of a high interface strain polymer electrolyte for a lithium metal battery, and belongs to the technical field of lithium metal batteries, and the preparation method specifically comprises the following steps: firstly preparing a precursor solution A containing a lithium salt and an organic solvent, then preparing a precursor solution B obtained by mixing a polymer monomer, an initiator, a cross-linking agent and the lithium salt, mixing the precursor solution A and the precursor solution B, and carrying out vacuum drying to obtain the high interface strain polymer electrolyte for the lithium metal battery. And assembling a lithium metal battery by using the polymer as an electrolyte, and drying to obtain the high interface strain polymer electrolyte which is formed in situ in the positive and negative electrode interfaces of the lithium metal battery. By designing the proportion of fluorine element and oxygen element in a polymer electrolyte chain segment, the coordination strength of Li-O in a polymer electrolyte body phase is reduced, and the interface volume deformation during polymer lithium ion removal is improved, so that the potential difference of an electrolyte / lithium metal interface is reduced, the interface lithium deposition is homogenized, and the lithium dendrite growth is inhibited; and the cycling stability of the lithium metal battery is finally improved.

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 relates to the technical field of new energy materials and devices, and discloses a lithium-sulfur battery difunctional diaphragm and a preparation method thereof, the lithium-sulfur battery difunctional diaphragm comprises a diaphragm substrate and a load slurry, the load slurry is coated on the surface of the diaphragm substrate; the loaded slurry comprises an electrocatalyst material, and the electrocatalyst material is a monatomic catalyst carbon-based material / diatomic catalyst carbon-based material. The monatomic catalyst carbon-based material is a nickel monatomic catalyst carbon-based material or a cobalt monatomic catalyst carbon-based material; the diatomic catalyst carbon-based material is a nickel-cobalt diatomic catalyst carbon-based material. The nickel-cobalt diatomic catalyst coupled carbon-based material is applied to the field of lithium-sulfur batteries and serves as a lithium-sulfur battery diaphragm modification material, sulfur redox kinetics can be promoted, the shuttle effect can be inhibited, lithium ion flux can be induced, so that lithium dendrite growth is inhibited, and finally the cycle performance of the lithium-sulfur batteries is improved.

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

The invention provides a solid electrolyte for a lithium battery and a preparation method and application thereof, and belongs to the technical field of solid electrolytes.The solid electrolyte is prepared from, by mass, 40-75 parts of lithium salt, 10-30 parts of cross-linking agent, 5-25 parts of nanoscale silicon borate glass fiber and 1-10 parts of photoinitiator. The lithium salt, the cross-linking agent, the nanoscale silicon borate glass fiber and the photoinitiator are adopted as raw materials, a polymer component formed after ultraviolet curing has high mechanical performance, a stable electrolyte-electrode interface can be formed, growth of lithium dendrites can be effectively inhibited, the risk of short circuit of the battery is reduced, and the service life of the battery is prolonged. Therefore, the overall safety of the battery is improved, and the service life of the battery is prolonged. As an inorganic filler, the nanoscale silicon borate glass fiber is beneficial to reducing the crystallinity of a polymer component and increasing an amorphous phase region, so that rapid migration of lithium ions is facilitated, and the ionic conductivity and coulombic efficiency of the battery are improved.

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.