45 results about "Strong electrolyte" patented technology

The utility model relates to the technical field of batteries, and discloses a diaphragm of a battery cell, the battery cell and a battery pack. The separator includes a base film and a hybrid coating. The mixed coating is coated on a single surface or double surfaces of the base film; the mixed coating comprises a heat-resistant material and polymer particles, the particle size of the polymer particles is larger than that of the heat-resistant material, the polymer particles at least partially protrude out of the heat-resistant material to form supporting protrusions, and the supporting protrusions are suitable for forming a gap between the diaphragm and the pole piece after the diaphragm and the pole piece are laminated. According to the diaphragm of the battery cell provided by the utility model, the electrolyte infiltration effect of the pole piece can be improved. And meanwhile, the polymer particles have relatively strong electrolyte absorption performance, can absorb and store part of electrolyte, are beneficial to infiltration of a battery cell pole piece, and continuously release the electrolyte in the cycle process of the lithium battery cell for supplementing the electrolyte consumed by the pole piece, so that the cycle life of the battery cell is prolonged.

The invention discloses a rigid PMMA (Polymethyl Methacrylate) nano-microsphere / flexible P (MMA-BA) nano-microsphere composite diaphragm and a preparation method thereof. The rigid PMMA nano-microsphere slurry and the flexible P (MMA-BA) nano-microsphere slurry are uniformly mixed according to the mass ratio of 1: (1-5) and then are used as a coating to be coated on the diaphragm, and the thickness of the coating is 1-5 microns. According to the rigid PMMA and flexible P (MMA-BA) composite diaphragm, the mechanical strength of the diaphragm can be effectively improved, high-temperature shrinkage of the diaphragm can be effectively inhibited due to the excellent thermal stability of the PMMA coating diaphragm, a wider safety window is provided for the interior of a battery cell, thermal runaway spreading is delayed or prevented, the safety performance of the battery cell is further improved, and the service life of the battery cell is prolonged. Meanwhile, due to the strong electrolyte absorption capacity of the flexible P (MMA-BA) material, the flexible P (MMA-BA) can slowly and continuously release electrolyte in the long circulation process of the battery cell, in addition, the elasticity of the flexible P (MMA-BA) can better adapt to the volume change of an electrode in the charging and discharging process, interface contact is maintained, and the circulation capacity of the battery cell is further greatly improved.

The invention discloses a high-voltage chloride solid electrolyte with a stable in-situ polyacrylonitrile flexible ion transmission interface layer and a preparation method and application thereof, and belongs to the technical field of solid electrolytes. According to the invention, an in-situ polymerization reaction is initiated by using polyvalent central metal ions contained in a specific chloride solid electrolyte to generate an electrophilic induction effect on a nitrile monomer, so that a uniform and complete polyacrylonitrile artificial organic flexible ionic conductor interface layer is formed on the surface of the chloride solid electrolyte; and the crystal structure and the ionic conductivity of the chloride solid electrolyte are not damaged. The lossless interface layer can effectively enhance the electrochemical stability of the solid electrolyte, can be matched with a high-voltage lithium ion positive electrode material, can enhance the air stability of the electrolyte and the mechanical stability of an electrode-electrolyte interface, and can remarkably inhibit the generation of pores and electrode cracks at the interface; the rate capability and the cycle life of the lithium ion solid-state battery 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 method for determining haloacetic acid in different water qualities through liquid-liquid extraction derivative gas chromatography, and belongs to the technical field of water quality analysis and detection.According to the method, at least one gas chromatograph, a sampling bottle with a plug, an extraction bottle with a plug, a derivative bottle with a plug, a microsyringe, a vortex oscillator and a heating block are used for determination of the method, the method mainly comprises the test steps of water sample collection, water sample extraction, water sample derivation, water sample determination and optimization detection, wherein optimization items mainly comprise a strong electrolyte, a volume ratio of sulfuric acid to methanol, instrument working conditions and the like. The method realizes detection of haloacetic acid in different water qualities, is high in sensitivity, good in accuracy and high in precision, and is suitable for drinking water, seawater, lake water, industrial wastewater and the like.

The application discloses a preparation method for improving stability of a proton conductor electrolyte in carbon dioxide, relates to the technical field of solid oxide batteries and solid oxide electrolysis cells, and is characterized by the following steps: through a nano-additive surface modification method, a nano-structure additive of an alkaline earth metal oxide, or a transition metal oxide, or a VA main group metal oxide is prepared on the surface of a barium cerate and a barium zirconate series electrolyte obtained through a solid phase reaction method by using a vacuum impregnation method, and an alkaline proton conductor electrolyte with a surface modification additive is obtained. The alkaline proton conductor electrolyte with the surface modification nano-structure additive obtained by the application can be applied to a proton type carbon hydrogen ceramic membrane fuel cell or high-temperature electrolysis carbon dioxide, so that the stability of the electrolyte can be effectively enhanced, and ohmic loss can be reduced, thereby greatly improving the performance and stability of the solid oxide fuel cell and the electrolysis cell under a carbon dioxide atmosphere.

The application provides a modified PEO-based composite solid-state electrolyte and a preparation method and application thereof, and the modified PEO-based composite solid-state electrolyte comprises MS2Br2, PEO and a lithium-based electrolyte, wherein the element M is at least one of Mo and Nb. The PEO-based solid-state electrolyte is modified by using MS2Br2, so that the conductivity of the PEO-based solid-state electrolyte can be effectively improved, the interface stability of the electrolyte and the negative electrode is enhanced, and then the electrical performance and the cycle performance of the solid-state electrolyte battery are improved.

The invention discloses a layered sulfide sodium-ion battery positive electrode material and application, and belongs to the technical field of sodium-ion battery positive electrode materials, the layered sulfide sodium-ion battery positive electrode material comprises a two-dimensional layered compound Na2AgSbS3, and can also comprise a carbon-based material. The preparation method of the two-dimensional layered compound Na2AgSbS3 comprises the following steps: mixing a silver source, an antimony source, a sulfur source and a sodium source, dissolving to obtain slurry, uniformly dispersing the slurry, sealing, heating at 150-180 DEG C for 110-130 hours, and purifying the obtained product to obtain the two-dimensional layered compound Na2AgSbS3. The layered sulfide sodium ion battery positive electrode material disclosed by the invention is excellent in structural stability, rich in intrinsic sodium and high in first efficiency, has high-potential oxidation-reduction activity, is beneficial to rapid transportation of Na < + > due to a layered channel, and is high in electrolyte compatibility and wide in application prospect.

The present invention belongs to the technical field of electrode material preparation and provides a porous long-cycle silicon-carbon negative electrode material and a preparation method thereof. SiO2 microspheres are prepared by a sol-gel reaction, and silicon dioxide particles are generated by hydrolysis and polycondensation to form a SiO2@MgO composite structure, which is then subjected to a high-temperature reduction reaction with magnesium powder and chemical etching to form a porous silicon matrix; PANI material is prepared, a LATP layer is formed using a precursor sol to improve the ionic conductivity of the binder, and active functional groups are introduced on the PANI@LATP surface, followed by a photo-initiated polymerization reaction to form a functionalized binder; a Li3PS4 solid electrolyte is prepared, and a conductive protective layer is coated with polydopamine to enhance the bonding between the electrolyte and the silicon negative electrode; the porous silicon-carbon composite material is dispersed with Li3PS4@PDA and PANI@LATP binders to prepare a porous long-cycle silicon-carbon negative electrode material.

The application belongs to the technical field of lithium ion batteries, and specifically provides a C9H7F3O3 modified LLZTO-based PEO composite solid electrolyte and a preparation method thereof, to solve the problem that the PEO-based solid electrolyte in the prior art is prone to lithium dendrite puncture in the cycle process. The application introduces C9H7F3O3 (4-methoxy-2-trifluoromethylbenzoic acid) as a modifier. Due to its unique bifunctional structure, on the one hand, the carboxyl group can undergo acid-base neutralization reaction with the main impurities on the surface of LLZTO, eliminating the serious passivation of high impedance impurities on the interface, and enhancing the interface stability of the electrolyte to lithium metal; on the other hand, the trifluoromethyl group optimizes the lithium ion transmission mechanism by virtue of its strong electron-withdrawing ability and unique "weak solvation" effect; at the same time, the trifluoro group also helps to induce the construction of a stable solid electrolyte interface film rich in LiF, and cooperatively inhibits the growth of lithium dendrites, thereby significantly improving the cycle life of the all-solid-state lithium ion battery.

The invention relates to the technical field of cross-linking agents, and discloses a preparation method of a high-performance covalent cross-linking agent for acid fracturing, which comprises the following steps: dissolving cyanuric chloride in an organic solvent at low temperature, adding aliphatic primary amine, and adding an alkaline neutralizer to maintain the pH value to prepare a monochloro substituted intermediate solution; polyfunctional amine is added for polycondensation, the volume fraction of the mixed solvent is adjusted so that the solubility parameter can be matched with the hyperbranched skeleton, and a hyperbranched intermediate is prepared by controlling the branch growth rate through solvation; the surface shielding steric hindrance layer is constructed by adopting zwitterionic amine and hydrophobic tertiary amine for surface modification, conformation extension of a zwitterionic structure under strong electrolyte is used for counteracting molecular chain shrinkage, thermal collapse is inhibited by combining hydrophobic association microdomain and skeleton rigidity, and the crosslinking activity in a high-temperature acid environment is maintained.

This invention relates to the field of metal oxide technology, specifically to a highly dispersed nano-gadolinium oxide and its preparation method. The preparation method includes: activating surface sites through weak acid etching, pulsed ultrasonic depolymerization, and hydrothermal re-hydroxylation; adsorption using a polycarboxylic acid chelating agent; introducing hydrophobic chains and tertiary amine groups through sequential amidation; forming a strongly hydrated outer layer through beet alkalization; and finally, ultrafiltration desalting and concentration. The nano-gadolinium oxide dispersion obtained by this method has advantages such as narrow particle size distribution, low viscosity, good storage stability, and strong electrolyte resistance, making it suitable for high-end applications such as polishing slurries and coating precursors.

The present invention provides a super-amphiphilic coating that can conduct lithium ions, a preparation method and application thereof, a diaphragm, an electrode and a lithium-ion battery, and relates to the field of battery technology. The super-amphiphilic coating that can conduct lithium ions provided by the present invention comprises an amphiphilic material and a lithium-ion conductor nanomaterial; the amphiphilic material is coated on the surface of the lithium-ion conductor nanomaterial. Among them, the lithium-ion conductor nanomaterial provides good lithium-ion conductivity, and the amphiphilic material coating layer and the lithium-ion conductor nanomaterial constitute a micro-nanostructure that can provide super-oleophilic and super-hydrophilic capabilities. Therefore, the super-amphiphilic coating provided by the present invention can be used as a coating for the diaphragm and current collector of a lithium-ion battery. Its extremely strong electrolyte affinity can accelerate the back absorption of the electrolyte and improve the liquid absorption capacity of the battery core without affecting the electrochemical performance. Moreover, the micro-nanostructure and polymer components of the super-amphiphilic coating have good liquid retention capabilities, which help to alleviate the extrusion of the electrolyte during the expansion process.

The invention provides a method for recycling valuable metal elements from a waste lithium battery through wet ball milling, and relates to the technical field of resource recycling. The method comprises the following steps: discharging the waste lithium battery, and removing an electrolyte, a diaphragm and a shell to obtain a copper-aluminum-pole piece mixture; crushing the copper-aluminum-pole piece mixture to obtain mixed electrode powder containing copper and aluminum; the mixed electrode powder containing the copper and the aluminum is mixed with a strong electrolyte solution, wet slurrying ball milling is carried out, high-valence metal in the mixed electrode powder is reduced through the copper and the aluminum, and a ball-milled slurrying material is obtained; and finally, valuable metal elements are extracted from the ball-milled slurrying material. The recovery method provided by the invention has the advantages of short flow, no need of a sorting process, low equipment investment, no introduction of an exogenous reducing agent, and realization of clean production; and reduction roasting is not needed, so that residual aluminum in the electrode powder is prevented from being combined with lithium in the reduction roasting process, the leaching rate of lithium is reduced, and meanwhile, energy and medicine consumption caused by high-temperature reaction is also avoided.

The invention relates to the field of negative electrode materials, and provides a super-capacity and overpressure graphite negative electrode material which is prepared by modifying graphite through organic amine hydrochloride, so that the surface of the graphite carries a certain amount of active groups, and the active groups are chemically bonded with resin which is subsequently coated on the surface of the graphite, so that the super-capacity and overpressure graphite negative electrode material is obtained. The chemical bonding greatly enhances the interface bonding strength of the resin and the graphite, the resin forms a coating layer with a stable structure on the surface of the graphite, and the negative electrode material obtained after graphitization treatment has the characteristics of high capacity, high compaction, good rate capability, strong electrolyte compatibility and the like.

The invention provides a sulfide composite electrolyte membrane and a preparation method thereof, and belongs to the technical field of electrolyte. The sulfide composite electrolyte membrane provided by the invention comprises the following components in percentage by mass: 1-3wt% of polytetrafluoroethylene; 0.5 to 2 weight percent of sulfydryl-polyethylene glycol-amino; and the balance of sulfide electrolyte. According to the invention, sulfydryl-polyethylene glycol-amino is used as an interface stabilizer to coordinate lithium ions in sulfide electrolyte to form a dynamic interface layer and relieve stress concentration, and sulfydryl and metal elements in a high-voltage positive electrode form a stable disulfide bond, so that interface contact between an electrolyte layer and an electrode layer is enhanced; amino groups are combined with hydroxyl groups on the surface of the positive electrode through hydrogen-bond interaction, so that interface side reaction is inhibited, and interface degradation of sulfide electrolyte and the high-nickel positive electrode is inhibited through the synergistic effect of sulfydryl and amino groups; in addition, polytetrafluoroethylene is added as a fibrosis agent, and a three-dimensional fiber network is formed through shear induction, so that the mechanical strength of the electrolyte membrane is enhanced.

The invention discloses a high-voltage-resistant gel polymer electrolyte for a supercapacitor and a preparation method and application thereof, and belongs to the technical field of supercapacitors. In the electrolyte, the high-pressure-resistant additive, the auxiliary additive, the lithium salt and the mixed solvent are reasonably matched. The high-pressure-resistant additive contains two key functional groups, namely trifluorosulfonyloxy and cyano, so that a stable multifunctional protective layer can be constructed on the interface of the positive electrode and the negative electrode, and the problem of interface degradation is solved. According to the preparation method, additives and lithium salt are added step by step, a cross-linked structure is finally formed on the surface of the electrode in situ, the binding force of the electrolyte and the electrode is enhanced, and smooth ion transmission is guaranteed. When the composite material is applied to preparation of a supercapacitor, the performance and stability of the supercapacitor under a high-voltage working condition can be improved, the energy density and the power density are improved, the service life is prolonged, the requirement of the market for the high-performance supercapacitor is met, and technical development and application of the supercapacitor are promoted.

The present invention relates to a secondary battery manufacturing apparatus and manufacturing method, and, more particularly, to a secondary battery manufacturing apparatus and manufacturing method, which are capable of effectively performing degassing and enhancing impregnation for an electrolyte. According to one embodiment of the present invention, the secondary battery manufacturing method can be provided, the method comprising: a filling step of filling a battery case with an electrolyte; an insertion step of inserting an electrode assembly into the battery case; and a degassing step of connecting an adapter to the electrode assembly, transmitting excitation of the adapter to the electrode assembly, and exciting the electrolyte through the electrode assembly so as to degas same.

The invention discloses a bionic cocklebur fruit-shaped Mo modified Na2Mn8O16 nano material and a preparation method thereof, and belongs to the field of inorganic nano materials. The preparation method comprises the following steps: dissolving sodium molybdate dihydrate, potassium permanganate and urea in deionized water, and carrying out hydrothermal reaction, filtering, drying and calcining treatment to obtain a target product. The material presents a unique bionic multi-thorn structure in microstructure, the surface is provided with densely distributed burr-shaped protrusions, the length of the protrusions is about 30-50 nm, and the protrusions are radially arranged to form an open system with a high specific surface area. Through Mo modification and synergetic thorn morphology, the permeability of the electrolyte and the zinc ion migration rate are remarkably enhanced, and the conductivity and the structural stability of the material are effectively improved, so that the material shows excellent electrochemical performance. The process is simple, and the prepared material has a good application prospect in the field of zinc ion battery positive electrodes.

The invention provides an argyrodite-based complex-phase solid-state electrolyte material as well as a preparation method and application thereof, and relates to the technical field of solid-state batteries. The complex-phase solid electrolyte material is characterized in that a metal / oxygen co-doped lithium-sulfur-argyrodite phase is used as a matrix, and heterogeneous-phase disulfide nanoparticles are dispersed in the grain boundary of the matrix. The lithium argyrodite type solid electrolyte with high ionic conductivity is used as a base material, and high-valence metal is introduced to be co-doped with an oxygen element, so that formation of sulfur vacancies is promoted, and a lithium ion diffusion energy barrier is reduced. And meanwhile, the interface action of the heterogeneous-phase disulfide nanoparticles at the grain boundary is beneficial to reducing the internal interface resistance of the electrolyte, so that the conduction efficiency of lithium ions is further improved. In addition, due to the high electronegativity of the high-valence metal and the oxygen element and the in-situ passivation effect of the heterogeneous-phase disulfide, the stability of the electrolyte under the high-voltage condition is remarkably enhanced, the side reaction between the electrolyte and a positive electrode material is reduced, and the overall cycle performance of the battery is improved.

The invention provides a boron nitride-zirconium oxide composite solid electrolyte-based dual-ion conducting membrane, which is prepared from the following raw material components: 12xg of hexagonal boron nitride nanosheets, 8xg of zirconium oxide nanoparticles, 5xg of proton conductors, 150xg of binders and 800xml of silane coupling agents, wherein x is greater than 0; the preparation method comprises the following steps: pretreating raw materials; blending the solutions to prepare composite slurry; ball-milling to a specific particle size; grafting the ionomer to form a covalent bond; casting to form a film; stacking, hot-pressing and cross-linking the membranes; and activating to obtain the dual-ion conduction membrane. The dual-ion conduction membrane can realize high ion mobility, oxygen ion conductivity of 0.12 S / cm at 800 DEG C, mechanical strength of 500 MPa or above, excellent interface stability, substantial enhancement of the structural stability and creep resistance of an electrolyte layer, and prolongation of the service life of a fuel cell.

The invention relates to a method for removing iron and aluminum impurities in strong acid liquid, and belongs to the field of hydrometallurgy and resource utilization. The method specifically comprises the following steps: adding manganese monoxide powder (MnO) into a strongly acidic aqueous solution containing iron and aluminum, and gradually adjusting the acidity of the system under a mild condition, so that iron and aluminum ions form insoluble precipitates; after solid-liquid separation and washing, the removal rate of iron and aluminum exceeds 90%, and the loss of target elements such as magnesium and lithium is small. According to the method, introduction of exogenous sodium salt is avoided, the ionic strength shielding effect caused by strong electrolyte such as NaCl is effectively avoided, a recessive chlorine salt buffer system is prevented from being formed, and it is ensured that pH adjustment is more flexible and controllable. The method is suitable for pretreatment processes of various acidic industrial liquids such as titanium slag water quenching liquid and lepidolite pickle liquor. The method has the advantages of low raw material cost, large precipitate particles, easiness in filtration, mild operation conditions and the like, and is suitable for industrial-scale application and popularization.

This invention relates to a bipolar membrane electrodialysis method for preparing lithium hydroxide from lithium malate, employing a two-compartment bipolar membrane electrodialysis system. First, a lithium malate solution is introduced into the acid-producing chamber, deionized water into the alkali-producing chamber, and a strong electrolyte solution into the anode and cathode chambers. Then, current is applied to both sides of the anode and cathode plates for electrodialysis, resulting in high-purity lithium hydroxide in the alkali-producing chamber and high-purity malic acid in the acid-producing chamber. This method produces high-purity lithium hydroxide with few impurities. The H2Ma cycle generated in the acid-producing chamber maximizes lithium resource utilization with minimal waste, achieving utilization of all raw materials and products in the entire lithium hydroxide preparation process. It is environmentally friendly, highly efficient, and produces virtually no pollutants. The current efficiency of the entire lithium hydroxide preparation process is 40-63%, and the energy consumption is 17-39 kWh / kgLiOH. This method has significant economic value and importance for the recycling of waste lithium batteries, representing a simple and green method for lithium recovery.

The application discloses a sulfide solid-state electrolyte based on a grain boundary engineering and a molecular bridging in-situ gradient interface layer and a preparation method thereof, and belongs to the technical field of solid-state battery materials. The method is characterized in that: firstly, a silane-polyethylene glycol-mercapto coupling agent is used to perform surface modification on a grain boundary modifier, so that the coupling agent is anchored and mercapto active sites are reserved; secondly, the modified modifier is ball-milled with a sulfide electrolyte, and the grain boundary is activated and annealed to reserve coupling activity; then, the ball-milled modified modifier is ball-milled with a phosphorus-free sulfide precursor, and a chemical bridging is formed between the mercapto and the precursor, so that the precursor is uniformly adsorbed in the grain boundary in a directional manner; finally, a phosphorus-free sulfide interface layer with a gradient change in composition and density is generated in-situ through gradient heat treatment. The application can enhance the air stability of the electrolyte and the electrode compatibility, and solves the problems of weak bonding force, easy peeling and high interface impedance of a traditional coating layer.

The invention provides a solid electrolyte membrane and a preparation method thereof, and belongs to the technical field of electrolyte. The preparation method comprises the following steps that taurine is used for modifying polydopamine nano-particles to obtain modified polydopamine nano-particles, then sulfide electrolyte, polytetrafluoroethylene and the modified polydopamine nano-particles are compounded to prepare the electrolyte membrane, the polytetrafluoroethylene enhances the cohesive force of the electrolyte particles, and the electrolyte membrane is formed by compounding the sulfide electrolyte, the polytetrafluoroethylene and the modified polydopamine nano-particles. The modified polydopamine nanoparticles enhance the cohesion of the electrolyte particles, the mechanical strength of the electrolyte membrane can be remarkably enhanced through the cooperation of the modified polydopamine nanoparticles and the electrolyte particles, meanwhile, the lithium ion transmission performance is enhanced through taurine modified polydopamine, and finally the composite electrolyte membrane which is high in ionic conductivity and capable of effectively resisting lithium dendrite puncture can be obtained.

The invention discloses an ultrasonic detection device and method for electrolyte infiltration conditions of a lithium ion soft package battery, and belongs to the field of ultrasonic nondestructive detection of batteries. Comprising a linear ultrasonic phased array sensor, a multi-channel ultrasonic excitation acquisition module, a three-axis motion control module and upper computer software. The sensor part adopts a wheel type phased array sensor made of sound transmission rubber, and is characterized by dry coupling, that is, a detected battery does not need to be immersed in a liquid coupling agent, so that the damage to a battery sample is eliminated. In addition, for electrolyte infiltration detection, traditional X-rays and infrared rays have strong penetrating power to electrolyte, so that the electrode infiltration distribution condition cannot be visually detected. The method has the following advantages that 1) the non-charge-discharge solid-state coupling type ultrasonic phase control C scanning imaging of the lithium ion soft package battery production line can be realized, and 2) the method has the detection advantages of low detection cost, high safety coefficient, non-intrusive detection, high working efficiency and the like.

The invention relates to a method for preparing graphene quantum dots, which comprises the following steps of: preparing retired graphite into a positive electrode and a negative electrode, immersing one end of the positive electrode and one end of the negative electrode into electrolyte, respectively communicating the other ends of the positive electrode and the negative electrode with the positive electrode and the negative electrode of an external circuit, and electrifying for electrolysis to obtain the graphene quantum dots, wherein the electrolyte is deionized water, a volatile weak electrolyte or a volatile strong electrolyte of which the concentration is less than or equal to 0.002 M. According to the method, the retired graphite is used as the positive electrode and the negative electrode, the graphene quantum dots are prepared through electrolysis in the deionized water or the volatile weak electrolyte or the volatile low-concentration strong electrolyte, the preparation process conditions are simple, impurities in a reaction system are few, and the graphene quantum dots can be obtained by directly drying the electrolyzed solution; and the problems of impurity removal process and difficulty in treatment of waste liquid generated by the existing method are avoided.

The invention provides a composite solid-state electrolyte membrane, a solid-state lithium battery and a preparation method of the solid-state lithium battery, and relates to the technical field of solid-state batteries. According to the composite solid electrolyte membrane provided by the invention, the crosslinking additive is introduced to react with the polymer matrix, so that a stable crosslinking network structure is constructed in the membrane. And the cross-linked network structure can effectively enhance the interaction force between polymer chain segments and resist external stress, so that the mechanical strength and toughness of the electrolyte membrane are remarkably improved. And due to the enhancement of the mechanical property, even if the electrolyte membrane is ultrathin, the puncture of lithium dendrites can be effectively inhibited, so that the key of long cycle stability of the battery is realized. The formation of a cross-linked network structure possibly fixes the orientation of a polymer chain segment to a certain extent, and cooperates with an inorganic fast ion conductor filler to provide more continuous and efficient transmission channels for lithium ions, and possibly contributes to reducing the activation energy of ion migration, thereby generating positive influence on the ionic conductivity.

The application provides a composite electrode, a preparation method thereof and a full solid-state battery. The composite electrode comprises: a pole piece; and a composite electrolyte film arranged on the surface of the pole piece, wherein the composite electrolyte film comprises a first layer of electrolyte film close to one side of the pole piece and a second layer of electrolyte film adjacent to the first layer of electrolyte film and located away from the other side of the pole piece, the first layer of electrolyte film contains lithium salt, inorganic electrolyte and polymer, and the second layer of electrolyte film contains sulfide electrolyte, a binder and a dispersing agent. According to the composite electrode provided by the application, the coating of the electrolyte on the pole piece is uniform and reliable, and the mechanical strength of the electrolyte film as a whole is enhanced.

The invention provides a modified PEO-based composite solid electrolyte and a preparation method and application thereof, the modified PEO-based composite solid electrolyte comprises MS2Br2, PEO and a lithium-based electrolyte, and the element M is at least one of Mo and Nb. The PEO-based solid electrolyte is modified by adopting MS2Br2, so that the conductivity of the PEO-based solid electrolyte can be effectively improved, the interface stability of the electrolyte and a negative electrode is enhanced, and the electrical performance and the cycle performance of the solid electrolyte battery are further improved.