1915results about How to "Increase energy density" patented technology

The invention provides a sodium-ion battery positive electrode material and a preparation method thereof, a sodium-ion battery and electric equipment, and relates to the field of sodium-ion batteries. The positive electrode material of the sodium ion battery provided by the invention comprises an inner core and a shell, wherein the shell covers the inner core; the chemical formula of the inner core is NaaNixFeyMnzM1-x-y-zO2, wherein a is more than or equal to 0.9 and less than or equal to 1.05, x is more than 0 and less than 1.0, y is more than 0 and less than 1.0, z is more than 0 and less than 1.0, and 1-x-y-z is more than 0 and less than 1; the chemical formula of the shell is NaLarCa1-rO2, wherein r is more than 0 and less than 1; in the inner core, the element M comprises one or more of Al, Mg, Ti, Zr, Y, La, Ca, Zn, Cu, W, Li and B. The sodium-ion battery positive electrode material provided by the invention can reduce residual alkali on the surfaces of particles, can inhibit side reaction with an electrolyte, and improves the performance stability of the positive electrode material.

The invention belongs to the technical field of lithium ion battery negative electrode materials, and particularly relates to a method for preparing a lithium ion battery negative electrode material from sulfur-doped black phosphorus-carbon. A carbon material and sulfur powder are subjected to ball milling, uniform mixing and vacuum high-temperature calcination to obtain a sulfur-doped carbon material; and uniformly mixing the sulfur-doped carbon material with black phosphorus, and performing high-energy ball milling in an inert atmosphere to obtain the sulfur-doped black phosphorus-carbon composite negative electrode material. According to the preparation method provided by the invention, the black phosphorus, the carbon material and the sulfur are well combined, so that the high capacity of the material is ensured, the structural stability of the composite material can be improved, the polarization of the material is reduced, and the cycling stability and the rate capability of the battery are improved.

The invention belongs to but not limited to the technical field of electrode materials, and particularly relates to a high-tap-density lithium nickel manganese oxide positive electrode material, a preparation method and a lithium ion battery, the chemical general formula of the high-tap-density lithium nickel manganese oxide positive electrode material is LiNi < 0.5-x > Mn < 1.5-y > M < x > N < y > O < 4 >, 0.1, 0 < = y < lt >; 0.1, M and N are doping elements and comprise one or more of Mg, Co, Al, Zr, W, Sb, Ta and Ti; the material is micron-sized spherical secondary particles formed by stacking and aggregating nano-sized octahedral primary particles, and is uniformly dispersed without agglomeration; the spherical secondary particles are formed by mixing spherical secondary particles with large and small particle size distribution, and the average particle size range of the large particles is 3lt; d < 50lt >; the average particle size range of the small particles is 1lt; d < 50lt >; 2 [mu] m.

The invention relates to the technical field of electrochemistry, and particularly discloses a positive pole piece, an electrochemical device comprising the positive pole piece and an electric device. The positive pole piece comprises a first active material with a particle size of 4-20 [mu] m and a second active material with a particle size of 200-600 nm, the first active material comprises lithium manganese iron phosphate with the manganese content of m%, the second active material comprises lithium manganese iron phosphate and / or lithium iron phosphate with the manganese content of n%, and m and n meet the condition that m-n is larger than or equal to 15 and smaller than or equal to 85. According to the invention, by controlling the particle size distribution in the positive electrode active material and the manganese content relationship, the electrochemical device containing the positive electrode plate has excellent fast charging performance and energy density.

The invention discloses a 7-series aluminum alloy composite light source laser welding method, which is characterized in that stitch welding is carried out on double-layer 7-series aluminum alloy test pieces by using a composite light beam formed by a near-infrared laser beam and a blue laser beam, the thickness of the upper-layer 7-series aluminum alloy test piece is 1-2mm, and the thickness of the lower-layer 7-series aluminum alloy test piece is 2mm; before welding, removing an oxide layer on the surface of the aluminum alloy, then pressing up and down through a jig, and setting welding parameters and paths; during welding, light spots of a near-infrared laser beam and a blue laser beam are concentric and emitted at the same time, the two laser beams are coupled and focused to a swing welding head, and stitch welding is carried out according to set welding parameters and paths; the light spot diameter of the blue light laser beam is larger than that of the near-infrared laser beam. Near-infrared light and blue light form coaxial composite light spots and emit light at the same time, stitch welding is conducted on the double-layer aluminum alloy test piece in combination with the swing welding head, and the stitch welding device has the advantages of being high in welding efficiency, good in air hole state and few in splashing and cracks.

The invention discloses a high-capacity positive electrode electrolyte for all-vanadium liquid flow batteries, wherein the electrolyte contains a solid energy storage material with a concentration of 0.02-1 g / mL, and the main component is a targeted redox solid energy storage material containing ammonia-rich iron / copper ferrocyanide, which reacts with a positive electrode redox medium VO in a supporting electrolyte containing ammonium ions. 2+ / VO2 + With similar equilibrium potential, reversible redox reaction can occur to continue the charge and discharge process. The high-capacity all-vanadium liquid flow battery positive electrode electrolyte disclosed in the present invention uses low-cost solid energy storage materials as the main energy storage medium, so when using a lower positive electrode redox medium VO 2+ / VO2 + High capacity and energy can be achieved at low concentrations, and pentavalent vanadium VO2 + The concentration can enhance the temperature adaptability of the all-vanadium liquid flow battery system while reducing the electrolyte cost.

The invention relates to a high-temperature superconducting flywheel energy storage device and a control method of the high-temperature superconducting flywheel energy storage device. The problems that in the prior art, an electro-magnetic inductor motor has large standby loss, and the suspension force cannot be adjusted can be solved through the high-temperature superconducting flywheel energy storage device and the control method of the high-temperature superconducting flywheel energy storage device. The high-temperature superconducting flywheel energy storage device comprises a flywheel rotor. A stator core; a first high-temperature superconducting excitation coil; the stator iron core, the first high-temperature superconducting magnet exciting coil and the second high-temperature superconducting magnet exciting coil are arranged around a rotating shaft of the flywheel rotor in the circumferential direction of the flywheel rotor, and the first high-temperature superconducting magnet exciting coil and the second high-temperature superconducting magnet exciting coil are arranged on the two sides of the stator iron core in the extending direction of the rotating shaft respectively; the permanent magnet surrounds the rotating shaft and is arranged on one side of the flywheel rotor in the extending direction of the rotating shaft; and the control coil is arranged around the rotating shaft, and the control coil is arranged on the same side as the permanent magnet relative to the flywheel rotor.

The invention discloses a method for preparing a composite iron-based polyanion positive electrode material. The structural formula of the positive electrode material is represented as Na4Fe3 (PO4) 2 (P2O7) (at) Camp, mXenes are sodium ferric pyrophosphate compositely coated by an MXenes material and a carbonaceous precursor, and the preparation method comprises the following steps: weighing a sodium source, a ferrous source, a phosphorus source and a carbon source according to a stoichiometric ratio, uniformly mixing, grinding, spray-drying and sintering at high temperature to obtain the composite iron-based polyanion positive electrode material, and the carbon source comprises iron-nickel doped polyethylene glycol. The composite iron-based polyanion positive electrode material provided by the invention is remarkably improved in the aspects of energy density, rate capability and cycle life, and the preparation process is simple to operate, reliable in flow, quick in preparation process and easy for industrial production, so that an ideal scheme is provided for commercialized sodium ion battery positive electrode materials.

The invention relates to the technical field of sodium ion battery positive electrode materials, in particular to a carbon-coated sodium ferric phosphate pyrophosphate positive electrode material and a preparation method and application thereof.The preparation method includes the steps that carbon nanotubes and an organic carbon source serve as carbon sources to prepare two kinds of sodium ferric phosphate pyrophosphate particles, and the two kinds of particles are mixed in proportion and then sintered to obtain the carbon-coated sodium ferric phosphate pyrophosphate positive electrode material. In the carbon layer coated on the surface of the material, the carbon nanotubes and the organic carbon source exert respective conductive advantages to form a strong conductive network, so that the conductivity of the material is improved, and the overall structural rigidity of the material is enhanced.

The invention relates to the field of batteries, in particular to a negative plate and a battery comprising the negative plate. The negative plate comprises a negative current collector, a bottom coating and a negative active material layer, the bottom coating and the negative active material layer are positioned on one side or two sides of the negative current collector, the bottom coating is positioned between the negative current collector and the negative active material layer, the bottom coating comprises a three-dimensional structure formed by a first conductive binder, the first conductive binder comprises a first carbon nano tube, and the first carbon nano tube comprises a second carbon nano tube. The negative plate meets the following relational expression: 1.2 < = B / K < = 3.4, B is the length-diameter ratio of the first carbon nanotube, and K is the tensile strength of the negative current collector. According to the negative plate, the thickness of the priming coat can be greatly reduced, and the energy density of the battery is increased; the binding power between the negative electrode current collector and the negative electrode active material layer can be enhanced, the structural stability of the active material layer can be improved, the pole piece deformation and powder falling in pole piece processing and battery circulation can be improved, and the circulation expansion can be inhibited; the conductivity of the pole piece is improved and the fast charging performance of the battery is improved.

The invention relates to the technical field of batteries, in particular to a negative plate and a lithium ion secondary battery. The negative plate comprises a negative current collector and a negative active material layer positioned on at least one side surface of the negative current collector; the negative electrode active material layer comprises a first coating close to the negative electrode current collector and a second coating deviating from the negative electrode current collector; the thickness of the negative plate is 30-1000 [mu] m; the first coating comprises a first negative electrode active substance, the second coating comprises a second negative electrode active substance, and the second negative electrode active substance comprises a second graphite material and hard carbon; the ratio of the average particle size of the second negative electrode active material to the average particle size of the first negative electrode active material is L, 1lt; l < = 2.5; the outer surface of the negative electrode active material layer has a recess. The negative plate disclosed by the invention has excellent lithium ion conduction capability and capacity exertion, and the lithium ion secondary battery comprising the negative plate disclosed by the invention has relatively high energy density and rapid charging capability.

The invention provides a positive electrode active material, positive electrode slurry, a positive plate, a battery and a vehicle, and belongs to the technical field of batteries, the positive electrode active material comprises lithium manganese iron phosphate and nickel cobalt lithium manganate; wherein the mass ratio of the lithium manganese iron phosphate to the nickel cobalt lithium manganate is (50-95): (5-50); the chemical general formula of the nickel cobalt lithium manganate is LiNiaCobMn (1-a-b) O2, a is more than or equal to 0.6 and less than 1, b is more than 0 and less than 0.5, and a + b is more than 0 and less than 1. According to the present invention, the lithium manganese iron phosphate and the nickel cobalt lithium manganate are compounded to serve as the positive electrode active material, and the mass ratio of the lithium manganese iron phosphate to the nickel cobalt lithium manganate is controlled within the range of (50-95): (5-50), such that when the positive electrode active material is applied to the battery, the high safety performance can be provided while the high energy density is provided so as to improve the comprehensive performance.

The invention discloses a preparation method of a composite sodium iron phosphate positive electrode material with high compaction density, which is characterized by comprising the following steps: (1) mixing a sodium source, an iron source, a phosphorus source, a carbon source and the like for preparing the composite sodium iron phosphate positive electrode material in proportion to obtain a precursor aqueous solution; (2) adding a surfactant into the precursor aqueous solution, grinding and uniformly mixing to obtain a homogeneous precursor aqueous solution; (3) carrying out drying granulation on the homogeneous precursor aqueous solution by using a spray drying technology to obtain composite sodium ferric phosphate precursor particles; and (4) performing high-temperature heat treatment on the composite sodium ferric phosphate precursor particles under the protection of inert gas to obtain the composite sodium ferric phosphate positive electrode material. The sodium-ion battery positive electrode material and the electrode plate with high compaction density can be obtained, the reversible specific capacity of the sodium-ion battery is improved, the problem of low gram capacity exertion is solved, the battery capacity is improved, and high-quality sodium-ion battery supply is provided for the field of energy storage.

The invention relates to the field of new energy batteries, in particular to an oxyhalide solid electrolyte composite material, a preparation method thereof and a battery, the oxyhalide solid electrolyte composite material comprises a core particle and a coating layer coating the surface of the core particle; wherein the inner core particle comprises LiaMObXc, the coating layer material comprises LiaMObXc-dFd, a is greater than or equal to 0.1 and less than or equal to 5w, and d is greater than or equal to 0.1 and less than or equal to 0.5 w; b < = 2, 2 < = c < = 6, 0lt; d < = 2; m is selected from at least one of Hf, Zr, Nb, Ta and Ti, and X is selected from at least one of Cl, Br and I. The oxyhalide solid electrolyte composite material disclosed by the invention is relatively low in fluorine content in a main body, so that the negative influence of over-low conductivity caused by high overall fluorine content of the material is reduced, and the electrolyte material is promoted to have excellent electrochemical oxidation potential and air stability while maintaining high ionic conductivity.

The invention relates to a lithium manganese iron phosphate positive electrode material and a preparation method thereof, a positive plate and a battery, and belongs to the technical field of methods or devices for directly converting chemical energy into electric energy. The lithium manganese iron phosphate positive electrode material comprises an inner core, a first coating layer arranged on the surface of the inner core and a second coating layer arranged on the surface of the first coating layer, the inner core is lithium manganese iron phosphate I, the first coating layer comprises lithium manganese iron phosphate II, and the second coating layer comprises a carbon material and an inorganic solid electrolyte. The lithium manganese iron phosphate positive electrode material not only can endow a battery with relatively high energy density, but also can endow the battery with excellent cycle performance.

The invention relates to the field of batteries, in particular to an all-solid-state thin film battery and a preparation method thereof. The all-solid-state thin film battery comprises a positive electrode current collector layer, a positive electrode layer, a solid electrolyte layer, a negative electrode layer and a negative electrode current collector layer, the thicknesses of the positive electrode layer and the solid electrolyte layer are 10 nm to 50 [mu] m, and the positive electrode layer is made of a material which contains a sulfur element and has the capacity of storing and discharging electricity; when the positive electrode layer is made of a material which contains a sulfur element and a metal element and has electricity storage and discharge capabilities, the thickness of the negative electrode layer is 0 nm to 50 [mu] m; when the positive electrode layer is made of a material which contains a sulfur element and has electricity storage and discharge capabilities, the thickness of the negative electrode layer is 10nm-50mu m; the thickness of the positive electrode current collector layer is 10 nm to 100 [mu] m; and the thickness of the negative current collector layer is 0 nm to 100 [mu] m. According to the invention, the cost of the battery can be effectively reduced, the capacitance of the battery is improved, and large-area and mass production of the battery can be realized.

The utility model relates to an electrode assembly and a battery monomer adopting the same, the electrode assembly consists of a positive plate, a negative plate and a diaphragm, the electrode assembly is provided with a positive lug and a negative lug, and the size of the negative plate is larger than that of the positive plate; the corner of the positive plate is an inner arc angle; the corner of the negative plate is an outer arc angle; the positive plates and the negative plates are stacked in sequence, and the diaphragms are arranged between the adjacent positive plates and negative plates. The corner of the negative plate is designed to be the outward arc angle, and the corner of the positive plate is designed to be the inward arc angle, so that the aluminum plastic film PP layer is effectively prevented from being scratched in the stacking and packaging processes of the electrode plates. According to the design, the stacking mode of the electrode plates is improved, the possibility of physical interference is reduced, and meanwhile, the reduction of loss in the battery assembly process is also facilitated.

The invention relates to a high-load composite iodine positive electrode based on an MXene electrochemical reaction regulator as well as a preparation method and application of the high-load composite iodine positive electrode. The high-loading-capacity composite iodine positive electrode comprises a porous self-supporting composite electrode film and an iodine active substance, wherein the porous self-supporting composite electrode film is formed by wrapping a carbon material with an MXene / cellulose network formed by mixing an MXene nanosheet, the carbon material and cellulose, and the iodine active substance is loaded on the porous self-supporting composite electrode film; wherein the iodine active substance comprises I <-> ions and I2; the MXene nanosheet is at least one of Ti < 3 > C < 2 > T < x >, Nb < 2 > T < x >, Mo < 2 > T < x > and V < 2 > T < x >.

The invention belongs to the technical field of batteries, and discloses a battery assembly method and a battery, and the method comprises the following steps: S1, coating a plurality of side surfaces of a pole group with insulating films; s2, a composite cover plate is arranged on the first surface of the pole group; s3, performing hot melting on the insulating film and the first insulating layer; s4, assembling the pole group of which the first surface is provided with the composite cover plate into the cavity of the battery shell; s5, installing a composite cover plate on the second surface of the pole group; s6, welding the composite cover plate and the battery shell; s7, welding the composite pole with the composite shell; and S8, realizing current conduction between the composite pole and the tab. Current conduction is finally realized by the tab and the composite pole, so that the influence of other welding procedures on the connection quality of the tab and the composite pole is avoided, and the tab extends out of the battery shell to realize current conduction with the composite pole, so that the occupation of the internal space is reduced, the utilization rate of the space is improved, and the production cost is reduced. And a space is provided for enlarging the pole group, and the energy density is improved.

The battery top cover for the secondary battery comprises a positive / negative terminal, a top cover substrate and a lower plastic part, the positive / negative terminal comprises a plane part and a protruding part formed by stamping, and the back surface of the protruding part is provided with a concave part; the protruding part of the terminal penetrates through the top cover substrate and the lower plastic part, the lower end of the terminal can be connected with the switching piece when the battery is assembled, and the plane part of the terminal is matched with the switching piece to clamp the top cover substrate and the lower plastic part; a positive / negative insulating ring, a fixing ring and a sealing ring are sleeved on the protruding part of the terminal; a plurality of upper bulges matched with the terminals and lower bulges matched with the top cover substrate are respectively arranged on the upper surface and the lower surface of the positive / negative electrode insulating ring; the array radiuses of the upper bulges and the lower bulges are different; a plurality of lower grooves matched with the upper bulges are formed in the plane part of the terminal; a plurality of upper grooves matched with the lower bulges are formed in the top cover substrate; an annular bulge is arranged on the upper surface of the fixing ring; sawtooth structures are arranged on the inner circumferential wall and the outer circumferential wall of the annular protrusion. According to the utility model, the simplification and integration of the structure are realized, and the performance and the manufacturing efficiency of the battery cell top cover are improved.

The invention provides a positive pole piece, a preparation method thereof and a lithium ion battery. The positive pole piece comprises a positive current collector and a negative current collector, the first active coating is arranged on the surface of at least one side of the positive electrode current collector; the raw materials of the first active coating comprise a first main material, a first conductive agent and a low-swelling binder; the second active coating is arranged on the surface of one side, relatively far away from the positive electrode current collector, of the first active coating; and raw materials of the second active coating comprise a second main material, a second conductive agent and a high-swelling binder. Different types of binders are introduced into the first active coating and the second active coating, so that the tortuosity and porosity of the pole piece are changed, the diffusion rate of lithium ions is effectively improved, the concentration polarization of the surface layer of the pole piece is reduced, and the rate and cycle performance of the battery are remarkably improved. Particularly, the positive pole piece can achieve the goal of improving the multiplying power and the cycle performance without increasing the proportion of the conductive agent.

The invention relates to a low-temperature graphite negative electrode material and a preparation method thereof, and belongs to the technical field of high polymer materials. According to the prepared low-temperature graphite negative electrode material, firstly, the surface of graphite is pre-oxidized through potassium persulfate, phosphorus pentoxide and concentrated sulfuric acid, and then under the action of sodium nitrate, potassium permanganate and hydrogen peroxide, graphite oxide is prepared; then, ammonium molybdate hydrate and thioacetamide are used as a molybdenum source and a sulfur source, graphite oxide is used as a supporting material, a molybdenum disulfide-graphite compound is synthesized, and the conductivity and the cycling stability are improved; secondly, the surface of the negative electrode is coated with amorphous resin carbon / nickel oxide, so that the ion diffusion efficiency of the low-temperature graphite negative electrode material is enhanced, and the electrochemical lithium storage performance is improved in a low-temperature environment; and finally, the surface of the amorphous resin carbon / nickel oxide is coated with a layer of polythiophene film, so that the rate capability of the negative electrode material is improved due to large surface area and high pores.

The invention relates to an aqueous alkaline zinc-iodine battery and a preparation method thereof, and belongs to the technical field of aqueous zinc-iodine batteries. The battery includes: a positive electrode; a negative electrode; and an aqueous alkaline electrolyte; wherein the positive electrode comprises a current collector, a positive electrode active material, a conductive agent and an adhesive, and the positive electrode active material is iodide; the aqueous alkaline electrolyte comprises a chlorine-containing additive, a zinc salt electrolyte, an alkaline inorganic salt and water. The aqueous alkaline zinc-iodine battery provided by the invention is low in cost and simple to manufacture. According to the aqueous alkaline zinc-iodine battery provided by the invention, the iodide is adopted as the positive electrode active material, so that instability and potential safety hazards caused by taking an iodine elementary substance as the positive electrode at present are avoided. The battery disclosed by the invention releases a high-potential discharge platform at 1.65-1.68 V, the discharge capacity reaches 372-385 mAh.g <-1 >, and the battery shows rapid oxidation-reduction kinetics and excellent long-acting cycle stability.

The invention provides a positive electrode material and a preparation method thereof, a positive electrode plate, a battery and an electric device. The preparation method of the positive electrode material comprises the following steps: preparing a layered oxide internal core material, wherein the layered oxide internal core material is a layered oxide containing sodium and transition metal; preparing a polyanion external coating material, wherein the polyanion external coating material comprises sodium ferromanganese pyrophosphate; and fusing the layered oxide internal core material and the polyanion external coating material in a mechanical fusion manner to obtain the positive electrode material with the layered oxide and polyanion compounded core-shell structure. The positive electrode material comprises a layered oxide internal core material and a polyanion external coating material; the core material in the layered oxide comprises Na1 + xMO2, X is more than or equal to-0.3 and less than or equal to 0.2, and M comprises at least one of Fe, Ni, Cu, Zn, Co, Ti and Mn; and the external coating material of the polyanion system comprises Na < 4 > Fe < 3-y > Mn < y > (PO4) < 2 > P < 2 > O < 7 > / C.

The invention relates to a thermoelectric double-storage energy supply system. The thermoelectric double-storage energy supply system integrates a double-water-turbine design of a production well and a recharge well. The system intelligently responds to power grid electricity price fluctuation and heat supply requirements, and the working mode of the water turbine is flexibly adjusted. In the thermoelectric linkage optimization stage, when the electricity price is in a low ebb, the first water turbine extracts geothermal water to supply heat, and residual heat is stored in the heat and electricity storage water tank and the water storage tank to deal with the electricity price peak. And meanwhile, the second water turbine reversely generates power by utilizing geothermal tail water and feeds back to the power grid. In the energy storage and release optimization stage, the two water turbines work cooperatively in the electricity price off-peak period, and electric energy is converted into potential energy to be stored in the water tank. At the peak of electricity price, the high-position potential energy water in the water tank is released, and the stored potential energy is converted into electric energy through reverse operation of the water turbine to provide stable power supply for a power grid. According to the system, dual storage of heat and electricity is realized, the consumption contribution to distributed new energy photovoltaic wind power utilization is improved, the light and electricity abandoning quantity is reduced, and the distributed new energy power generation of a power grid and the electrical load of a building are balanced.

The invention provides a solid-state battery and a preparation method thereof, and belongs to the technical field of secondary batteries. The solid-state battery comprises a positive pole piece, the positive pole piece comprises a positive active material layer, the positive active material layer comprises sulfide electrolyte, and the average particle size D50 of the sulfide electrolyte is larger than or equal to 50 nm and smaller than 1 micron. According to the solid-state battery disclosed by the invention, the doped and modified sulfide electrolyte in the positive active material layer is nanocrystallized, so that a closely distributed ion transmission network and a stable electrode / electrolyte interface are formed in the positive active material layer; good conductive circulation of the battery can be realized by adding a small amount of sulfide electrolyte into the positive active material layer, the energy density of the battery is improved, and the cycle life of the battery is prolonged; and meanwhile, the nanocrystallized sulfide electrolyte in the positive active material layer has higher structural strength, so that the nanocrystallized sulfide electrolyte can be prevented from cracking and powdering in the charge-discharge cycle process, and the storage life and the cycle life of the battery are further prolonged.

The invention provides a sulfur positive electrode, a lithium-sulfur battery and a preparation method of the lithium-sulfur battery. The sulfur positive electrode comprises a sulfur positive electrode membrane and an active lithium membrane covering the sulfur positive electrode membrane, the sulfur positive electrode membrane comprises active sulfur, a carbonaceous carrier framework and a solid electrolyte, and the mass ratio of the active sulfur to the carbonaceous carrier framework to the solid electrolyte is (5-35): (10-20): (55-75); the mass of the active lithium is 10-45% of the mass of the active sulfur, the active sulfur is adsorbed on the surface of the carbonaceous carrier framework, and the solid electrolyte is filled between the carbonaceous carrier frameworks adsorbed with the active sulfur. The lithium-sulfur battery comprises the sulfur positive electrode and a lithium-free negative electrode, active lithium and active sulfur react to form Li2Sx, and x is smaller than or equal to 4. According to the all-solid-state lithium-sulfur battery disclosed by the invention, potential safety hazards caused by using a metal lithium negative electrode are avoided; in addition, the active sulfur is cured in the all-solid-state electrolyte, so that the problem of sulfur shuttling is avoided; according to the all-solid-state lithium-sulfur battery, the solid electrolyte is used, a conventional liquid electrolyte is not used, and the battery is safe, reliable and high in energy density.

The invention provides a negative electrode plate. The negative electrode plate comprises a negative electrode current collector, a graphite negative electrode material layer positioned on the surface of the negative electrode current collector, and a mixed coating of graphite and polymer particles positioned on the surface of the graphite negative electrode material layer, the graphite negative electrode material layer comprises graphite, the mixed coating comprises graphite and polymer particles, and the average particle size D1 of the graphite in the graphite negative electrode material layer and the average particle size D3 of the polymer particles are both larger than the average particle size D2 of the graphite in the mixed coating. The glass transition temperature Tg of the polymer particles is 60 DEG C or below, the polymer modulus is 250-400 MPa, and the swelling degree in an electrolyte is 10-30%. The negative plate provided by the invention can form stable bonding with the diaphragm in the hot pressing process, and the bonding force is improved by more than one time; when the negative plate is applied to the lithium ion secondary battery, the cycle life of a battery cell can be effectively prolonged by more than 20%, and lithium is not separated out during charging.

The invention provides a silicon-based negative pole piece and a lithium ion battery comprising the same, and relates to the technical field of lithium ion batteries. Comprising a negative electrode current collector, a second active material layer arranged on at least one surface of the negative electrode current collector, and a first active material layer arranged on the surface of the second active material layer. The design of the two active material layers ensures high energy density, and meanwhile, the formula design is optimized by combining the bonding characteristic of the interface layer, so that large internal stress is prevented from being generated in the charging and discharging process; the organic porous cross-linked polymer is applied to the negative pole piece, and the polymer is loose and porous and can be subjected to cross-linked polymerization in a high-temperature process, so that negative pole particles are tighter, expansion of a silicon negative pole in a charging and discharging process can be buffered, and stripping and cracking of the pole piece are prevented.

The invention belongs to the technical field of lithium batteries, and provides a preparation method of a boron-doped coated lithium iron manganese phosphate positive electrode material and a lithium battery, and the method comprises the following steps: S10, performing first pretreatment based on a lithium source, an iron source, a phosphorus source, a dopant, a dispersant, a first MOF and a solvent to obtain a first precursor; s20, performing first sintering crushing on the first precursor in an inert gas atmosphere to obtain a lithium iron phosphate precursor; s30, performing second pretreatment based on the second MOF, deionized water, a carbon source, a dispersing agent and the lithium iron phosphate precursor to obtain a second precursor; and S40, grinding and drying the second precursor, and carrying out second sintering crushing in an inert gas atmosphere to obtain the lithium iron manganese phosphate positive electrode material. Wherein the first MOF is a boron-based MOF, and the second MOF is a manganese-based MOF. The lithium ion intercalation and deintercalation efficiency is improved, the specific capacity, the cycle capacity retention ratio, the compaction density and the safety of the battery are improved, and the performance of the material is improved from multiple aspects.