3762 results about "Lithium–sulfur battery" patented technology

The invention is directed in a first aspect to a sulfur-carbon composite material comprising: (i) a bimodal porous carbon component containing therein a first mode of pores which are mesopores, and a second mode of pores which are micropores; and (ii) elemental sulfur contained in at least a portion of said micropores. The invention is also directed to the aforesaid sulfur-carbon composite as a layer on a current collector material; a lithium ion battery containing the sulfur-carbon composite in a cathode therein; as well as a method for preparing the sulfur-composite material.

Systems and methods for accurately determining the state of charge and the relative age of lithium sulfur batteries are provided. The cell resistance and taper input charge of a particular type of lithium sulfur battery are respectively measured to determine the state of charge and age of the battery.

A positive active material of a lithium-sulfur battery includes a sulfur-conductive agent-agglomerated complex in which a conductive agent particle is attached onto a surface of a sulfur particle having an average particle size less than or equal to 7 μm. The sulfur-conductive agent-agglomerated complex is manufactured by mixing a sulfur powder and a conductive agent powder to form a mixture, and milling the mixture.

A lithium-sulfur battery is disclosed in one embodiment of the invention as including an anode containing lithium and a cathode comprising elemental sulfur. The cathode may include at least one solvent selected to at least partially dissolve the elemental sulfur and Li2S_x. A substantially non-porous lithium-ion-conductive membrane is provided between the anode and the cathode to keep sulfur or other reactive species from migrating therebetween. In certain embodiments, the lithium-sulfur battery may include a separator between the anode and the non-porous lithium-ion-conductive membrane. This separator may prevent the lithium in the anode from reacting with the non-porous lithium-ion-conductive membrane. In certain embodiments, the separator is a porous separator infiltrated with a lithium-ion-conductive electrolyte.

The invention relates to a functional composite membrane for a lithium-sulfur battery and a preparation method of the functional composite membrane. The composite membrane comprises a membrane for the lithium-sulfur battery and a functional modified layer, wherein the functional modified layer is located on the membrane for the lithium-sulfur battery, and comprises an electronic conductive material and/or inorganic oxides. Compared with the lithium-sulfur battery employing an ordinary battery membrane, the lithium-sulfur battery employing the functional composite membrane with the modified layer has a relatively high specific discharge capacity; the shuttle effect of the lithium-sulfur battery can be suppressed; the coulombic efficiency of the battery is improved; and the cycle performance of the battery is improved.

Disclosed is a method of charging a lithium-sulfur electrochemical cell wherein the lithium-sulfur cell comprises a cathode comprising an electroactive sulfur-containing material, an anode comprising lithium, and a nonaqueous electrolyte. Also disclosed are methods for determining charge termination when charging lithium-sulfur cells.

The invention discloses a lithium sulfur battery cathode material and a preparation method thereof. The lithium sulfur battery cathode material comprises a sulfur/ graphene oxide compound, wherein a functional polymer layer and an adhesive layer sequentially cover on the sulfur/ graphene oxide compound, and at least partial adhesive in the adhesive layer is crosslinked and combined with at least partial functional polymer material in the functional polymer layer. The preparation method of the lithium sulfur battery cathode material comprises the steps of: mixing powdered sulfur with graphene oxide, and carrying out high-temperature water heating on the mixture to form the sulfur/ graphene oxide compound; then, packaging the sulfur/ graphene oxide compound by the functional polymer material to obtain sulfur/ graphene oxide electrode material covered by the functional polymer material; and mixing the sulfur/ graphene oxide electrode material with the adhesive and the like, and carrying out high-temperature vacuum crosslinking reaction to obtain the target product. The lithium sulfur battery cathode material effectively improves the capacity and the cycle performance of an electrode; and the preparation technology of the lithium sulfur battery cathode material is simple and good in controllability, and meets the demand of large-scale production.

The invention provides a grapheme-coated sulfur/porous carbon composite material and a preparation method thereof, and relates to a grapheme-coated sulfur/porous carbon composite material used as the positive electrode material of a lithium-sulfur secondary battery and a preparation method thereof. The grapheme-coated sulfur/porous carbon composite positive electrode material provided by the invention can be used for solving the technical problem that the existing grapheme-coated sulfur-containing composite material used as the positive electrode material of a lithium-sulfur battery is low in electrochemical properties. The external surface of each of the particles of the grapheme-coated sulfur/porous carbon composite material provided by the invention is evenly covered with a graphene sheet, and a graphene conductive network is formed between the particles; the obtained grapheme-coated sulfur/porous carbon composite material has a hierarchical core-shell structure. The preparation method of the grapheme-coated sulfur/porous carbon composite material is obtained by adding a sulfur/porous carbon composite material to graphene slurry which is stable for a long time and in which graphene sheets are highly dispersed in water for mixing and coating. The positive electrode material has high specific capacity, long cycle life and excellent high-rate performance. Besides, the grapheme-coated sulfur/porous carbon composite material can be used as the positive electrode material of a lithium secondary battery.

The invention relates to a positive electrode of a lithium-sulfur battery with a multifunctional elastic protection layer. The positive electrode of the lithium-sulfur battery comprises a positive material layer and the multifunctional elastic protection layer, wherein the multifunctional elastic protection layer is formed on the surface of the positive material layer and comprises a polymer and/or a conductive carbon material; and the thickness of the multifunctional elastic protection layer is 0.1-50 microns. The multifunctional elastic protection layer is introduced to the surface of the positive material layer of the lithium-sulfur battery; the multifunctional elastic protection layer has elasticity and conductivity; and has no influence on charge and discharge processes of the positive electrode of the lithium-sulfur battery; compared with the positive electrode of the lithium-sulfur battery without protection from a multifunctional elastic layer structure, the prepared positive electrode of the lithium-sulfur battery with the protection of the multifunctional elastic layer structure has good stability; a structural damage to the positive electrode caused by the volume effect in a charge-discharge cycle process of the battery can be relieved; and meanwhile, the added multifunctional elastic layer structure can ensure that an active material in the positive electrode is not greatly dissolved into an electrolyte to cause the capacity loss.

The invention relates to a method for protecting anode of a lithium sulfur battery. A diaphragm functional protective coating can be used for effectively suppressing the generation of lithium dendrites on the surface of a lithium anode, improving the safety of the battery and prolonging the cycle life of the battery, and slurry mixing is carried out by controlling the types and the proportion of a carrier, an adhesive, an additive and the like of the coating to prepare a diaphragm with the functional protective coating for protecting the lithium anode. The operation process is simple, and the protective layer can be used for effectively suppressing the generation of the lithium dendrites; and meanwhile, the additive is continuously released from the carrier, a layer of the protective diaphragm is continuously formed on the surface of the lithium anode to protect the lithium anode, and the safety and the cycling performance of the lithium sulfur battery are further improved.

The invention discloses sulfenyl anode of a lithium-sulfur rechargeable battery and a preparation method thereof. The sulfenyl anode is prepared by the steps of: equally mixing sulfenyl compound active material, cyclodextrin binder and carbon conductivity agent, coating the mixture on an aluminum foil current collector and obtaining the sulfenyl anode after drying and pressing. The coating thickness is 50 to 100 microns and the aluminum foil thickness is 20 to 30 microns; the mass ratio of the sulfenyl compound active material, the cyclodextrin binder and the carbon conductivity agent is 7 to 8:0.6 to 1:0.6 to 1.5, wherein the sulfenyl compound active material is formed by the steps of: equally mixing carbon nano tube, sulfur and polyacrylonitrile according to the mass ratio of 0.1 to 0.2:6 to 8:1 and sintering the mixture in protection of inert gas at the temperature of 300 to 320 DEG C for insulation for 6 to 8 hours. By using the lithium-sulfur rechargeable battery with the sulfenyl anode and lithium metal cathode, the reversible capacity of the sulfenyl compound active material reaches 680mAh.g under 0.1C multiplying power charge-discharge condition; and compared with the discharge capacity of second circulation, the discharge capacity after 100 times of circulation decreases less than 10 percent.

The present invention discloses a preparation method of a complex lithium negative pole of a solid state battery, and belongs to the technical field of electrochemistry and new energy resources. The preparation method mainly comprises the steps: depositing lithium metal on three-dimensional carbon material or foam porous material gaps by using a heat infusing melting method or an electrodeposition method to obtain the complex lithium negative pole, wherein the application of a three-dimensional framework plays two roles, namely, providing adequate space for pre-storing lithium in the preparation process; providing a carrier for receiving metal lithium in a battery circulation process. The complex lithium negative pole can be widely applied in lithium metal batteries such as lithium ion batteries, lithium-air batteries, lithium-sulfur batteries, and solid state batteries. In the assembled symmetric solid state battery, under large electric current density of 5mA cm-2, a stable voltage decay (200mV) can still be kept after circulation for 100 times, in the battery circulation, the growth of lithium dendrites can be inhibited and the pole volume change can be stabilized, and the advantages of being good in circulation stability, and long service life can be realized; in the present invention, a carrier material is rich, and low in price; the process is controlled, the cost is low, and the batch production can be realized.

Disclosed is a material which enhances stability for lithium in all the batteries, which use the lithium metal as an electrode material, by using and applying a lithium-substituted perfluoro sulfonic acid (PFSA) material in the form of a membrane or a powder to a lithium anode. Methods of manufacturing the material are also enclosed.

The invention relates to a nano carbon material with a network structure consisting of polymer chains, in particular to a nano carbon sulfur composite material with a network structure suitable to be used in a secondary lithium sulfur battery anode and a preparation method thereof. The carbon sulfur composite material is formed by adopting the following steps of: introducing functional groups onto carbon particles by adopting the electric conductivity and the porosity of a carbon material and the reaction capacity of similar condensed aromatics of the carbon material and by means of an irreversible chemical reaction; introducing the polymer chains, wherein the polymer chains are stretched, bent and cross-linked on the surfaces of the carbon particles to form a cross-linked network structure; and compounding a sulfur element or a polysulfide (m is more than 2) containing -Sm- structure into the network structure to form the nano carbon sulfur composite material with the network structure. The carbon sulfur composite material has a rich cross-linked network structure, nano-scale network pores constrain the sulfur element or the polysulfide (m is more than 2) containing the -Sm- structure in the network, and the active substances are limited in a certain region to react, so that the composite material has predominant electrochemical performance.

The invention discloses a lithium-sulfur battery multilayer composite positive electrode and a preparation method thereof, and belongs to the field of electrochemical batteries. The lithium-sulfur battery multilayer composite positive electrode has a multiple composite structure consisting of a first graphene thin-film layer, a carbon/sulfur active substance layer, a second graphene thin-film layer and a polymer layer, and multi-element integrated design of the lithium-sulfur batteries is realized. The positive electrode is characterized in that the performances of the lithium-sulfur battery are realized by integrally designing elements of the lithium-sulfur battery, the first graphene thin-film layer plays a role of a current collector, so that the weight of the current collector in the battery is effectively reduced and the effective contact between the current collector and an active electrode material is improved; and the second graphene thin-film layer and the polymer layer play a role of a diaphragm, are equivalent to a solid electrolysis layer and a barrier layer of a polysulfide, and are capable of effectively increasing transmission of electrons and ions and greatly limiting shuttling of polysulfide ions. The multilayer composite-structure positive electrode is simple and easily controllable in preparation process, can be prepared in large scale with low cost, and has great application value.

The invention discloses a carbon nano tube-containing sulfur-based composite cathode material and a preparation method thereof. The sulfur-based composite cathode material is a ternary composite material AxByCz, wherein A is a dehydrocyclization product of an acrylonitrile-itaconic acid copolymer; B is elemental sulfur; C is a carbon nano tube; x is more than or equal to 30 weight percent and less than or equal to 60 weight percent; y is more than or equal to 30 weight percent and less than or equal to 60 weight percent; and z is more than or equal to 1 weight percent and less than or equal to 20 weight percent. The preparation method comprises the following steps of: in-situ polymerizing an acrylonitrile-itaconic acid monomer on the surface of the multi-wall carbon nano tube, and performing thermal treatment on both of the acrylonitrile-itaconic acid copolymer and the elemental sulfur, so that the sulfur is uniformly dispersed in a substrate formed by the dehydrocyclization of the acrylonitrile-itaconic acid copolymer. The carbon nano tube-containing sulfur-based composite cathode material and a lithium cathode form a secondary lithium-sulfur battery which is charged and discharged at the room temperature. The carbon nano tube-containing sulfur-based composite cathode material has the reversible specific capacity of 697 mAh/g and high cyclical stability.

The invention discloses gel electrolyte, which comprises a polymer matrix material, a non-aqueous solvent and an inorganic filler in a mass ratio of 1:5:0.1-1:20:1 and also comprises electrolyte containing 0.5 to 2.0 mol/L of electrolyte lithium salt. The invention also discloses a preparation method of the gel electrolyte. The preparation method comprises the following steps of: mixing the polymer matrix material, the non-aqueous solvent, the inorganic filler and the electrolyte containing the electrolyte lithium salt in an inert atmosphere, and stirring the mixed solution till dissolving at the temperature of between 40 and 90 DEG C. The invention also discloses an anode and a lithium sulfur battery prepared by using the gel electrolyte. The gel electrolyte provided by the invention has high ionic conductivity, and can avoid the dissolution of the sulfur anode and the reactants; the lithium sulfur battery containing the gel electrolyte has good cycle performance; and the method is simple, does not need a large amount of extracting agent, is safe and environment-friendly, and is favorable for large-scale industrialized production.

This patent application describes graphitic carbon nitride materials that are useful in electrochemical cells such as Lithium-Sulfur batteries. Also disclosed are lithium-sulfur batteries designed to incorporate these materials and methods of manufacturing the same. Batteries that include this material exhibit increased electrode kinetics of the lithium-sulfur electrochemical couple, phenomena that improve the specific capacity, usable lifetime and other desirable characteristics of these batteries.

The invention relates to a gel-type polymer electrolyte used for a lithium-sulfur secondary battery system, consisting of a polymer support body, an ionic liquid, an organic solvent, a mixed lithium salt and dioxide silicon particles. A preparation method comprises the following steps of: preparing an imidazolium-based ionic liquid, dioxide silicon and composite lithium salt into a gel liquid in a carbonic ester solution dissolved with macromolecular polymers, then coating, drying and obtaining the gel-type polymer electrolyte film. In the gel-type polymer electrolyte prepared by the invention, sulfides in the lithium-sulfur battery system can be effectively prevented from dissolving in a liquid electrolyte solution, the ionic conductivity is high, and noninflammability and no leakage are achieved; and for the polymer electrolyte, the preparation process is simple, and the raw material source is wide, so that the gel-type polymer electrolyte is suitable for industrial production.

An improved cathode suitable for lithium-sulfur batteries, a battery including the cathode, and a battery including a separator containing inorganic fillers are disclosed. The cathode includes sulfur and a metal oxide and optionally includes an additional polymeric material. The metal oxide reduces dissolution of sulfur at the cathode and reduces sulfur-containing deposits on the battery anode, thereby providing a battery with relatively high energy density and good partial discharge performance. The separator also reduces unwanted diffusion of sulfur species.

The invention relates to a pole piece of a positive electrode of a lithium-sulfur battery and a preparation method thereof. The pole piece takes gelatin as a binding agent to coat a positive electrode active material and a conductive additive on a current collector, thereby improving the adhesion and the dispersion of the electrode. Meanwhile, the pole piece of the positive electrode of the lithium-sulfur battery prepared by freeze-drying comprises a micro-porous structure, thereby reducing the infiltration resistance of electrolyte on the pole piece and improving the electrochemical reversibility and the cycle stability of the battery.

The invention relates to a carbon-sulfur composite material used for a positive pole of a lithium-sulfur battery. The carbon-sulfur composite material is characterized in that elemental sulfur is filled in a multi-hole hollow carbon ball which is synthesized through a simple template method, and the elemental sulfur is injected into the multi-hole hollow carbon ball by adopting a fusion diffused method; the carbon-sulfur composite material is used for preparing a positive pole material of a high-performance lithium-sulfur battery cell, the positive pole is composed of the carbon-sulfur composite material, a binding agent and an electric conduction agent, and polytetrafluoroethylene or polyvinylidene fluoride is used as the binding agent; and the electric conduction agent is a mixture of one or more than two of carbon nanometer fibre, electric conduction graphite, acetylene black and Super p in any proportion. The carbon-sulfur composite material provided by the invention has the advantages that compared with the reportorial lithium-sulfur secondary battery, the preparation method of the anode material is simple, the large specific capacity is 1450 Ahg-1, the coulomb efficiency is high and is greater than 99.0%, the cycle performance is good, the initial capacity is kept 93.6% after circulating for 50 weeks and the like, and the carbon-sulfur composite material is expected to be applied to the next generation large-scale stored energy batteries.

The invention discloses an anode material of a lithium-sulfur battery and a preparation method thereof. The anode material is formed by the compounding of elementary sulfur and porous three-dimensional grading carbon. The preparation method comprises the steps of preparing a precursor compound of the porous three-dimensional grading carbon with a solvothermal method, carbonizing to obtain the porous three-dimensional grading carbon, then compounding with the sulfur to obtain the anode material of the lithium-sulfur battery. The preparation method is simple and low in cost, the prepared anode material of the lithium-sulfur battery has high sulfur containing capability, and high ion transmission capability and conductivity, and can improve the high-rate capability and the high cycle performance of the lithium-sulfur battery.