354 results about "Lithium intercalation" patented technology

The invention relates to the technical field of batteries, in particular to a silicon-carbon negative electrode material and a preparation method and application thereof. The silicon-carbon negative electrode material comprises a carbon substrate, nanometer silicon particles and doping elements, the nanometer silicon particles are uniformly embedded in the carbon substrate, the doping elements are doped in the carbon substrate, and the doping elements comprise fluorine elements and phosphorus elements. The silicon-carbon negative electrode material disclosed by the invention has good uniformity, the nano silicon particles are uniformly embedded in the spherical carbon matrix, and the carbon matrix can effectively relieve volume expansion of the silicon particles in a lithium intercalation / deintercalation process, so that the cycle performance of a battery is improved; and fluorine and phosphorus elements are doped in the carbon matrix, so that the electron / ion conductivity of the silicon-carbon negative electrode material can be improved, and the rate capability of the battery is improved.

The invention discloses a silicon-carbon material and a preparation method and application thereof, belongs to the technical field of negative electrode materials, and overcomes the defect of high volume expansion rate of a silicon-based material in the prior art. The silicon-carbon material provided by the invention comprises porous carbon and silicon deposited in porous carbon channels; the porous carbon comprises mesopores and macropores, the pore diameter of the mesopores is greater than 10nm and less than or equal to 50nm, and the pore diameter of the macropores is greater than 50nm and less than or equal to 100nm; based on the total volume of the pores in the porous carbon, the volume fraction of the mesopores is 50%-75%, and the volume fraction of the macropores is 10%-20%; and the silicon deposited in the mesopores and the macropores is a hollow silicon nanotube. Silicon in the silicon-carbon material mainly exists in the form of hollow silicon nanotubes, and during lithium intercalation expansion, since expansion spaces are reserved in the hollow nanotubes, the lithium intercalation expansion of the whole silicon-carbon material is reduced.

The invention belongs to the technical field of new energy materials, and discloses a fused salt auxiliary valence gradient doped modified single crystal positive electrode material and a preparation method and application thereof. The preparation method comprises the following steps: mixing a transition metal source, a lithium source, a manganese source and a molten salt auxiliary agent, sequentially carrying out first sintering and second sintering, and removing the molten salt auxiliary agent to obtain a doped modified single crystal positive electrode material precursor; and tempering the doped modified single-crystal positive electrode material precursor to obtain the fused salt auxiliary valence gradient doped modified single-crystal positive electrode material, the doped modified single crystal positive electrode material prepared by the invention can effectively avoid the capacity loss of the material, significantly reduce lattice mismatch in the lithium intercalation / deintercalation process, and relieve the volumetric strain in the charge-discharge process. Meanwhile, the formed M-O bond can enhance the structural stability of the material and inhibit the formation of microcracks of the material. The preparation method of the positive electrode material is convenient for industrial application, and provides a thought for commercial modification of the positive electrode material.

The invention belongs to the technical field of lithium ion battery materials, and discloses a perovskite type titanate material as well as a preparation method and application thereof, the structural formula of the perovskite type titanate material is AxByTiOz, an A-site element is an alkali metal element, a B-site element is a Y element and / or a lanthanide element, 0 < x < = 1, 0 < y < = 1, and x + 3y + 4 = 2z. The perovskite type titanate material meeting the chemical general formula of AxByTiOz is designed, the obtained perovskite type titanate material AxByTiOz can be used as a lithium ion battery negative electrode material, compared with a lithium titanate negative electrode, the perovskite type titanate material AxByTiOz has high energy density brought by more ideal working potential, meanwhile, compared with a graphite carbon material, the perovskite type titanate material AxByTiOz has high lithium intercalation state thermal stability, and the performance of the perovskite type titanate material AxByTiOz is improved. And high safety and high energy density of the lithium ion battery can be considered at the same time.

The invention provides a lithium supplement composite layer and a preparation method thereof, a lithium supplement method, a pre-lithiated negative pole piece, a secondary battery and an electronic device, the lithium supplement composite layer comprises an interface layer and a lithium supplement layer which are laminated, the interface layer comprises interface particles and a binder, the interface particles comprise a lithium intercalation material and / or a conductive agent, and the binder comprises a lithium intercalation material and / or a conductive agent. The lithium intercalation material is selected from at least one of artificial graphite, natural graphite, hard carbon, a silicon-carbon material, a silicon-oxygen material, lithium titanate, tin and a tin-copper alloy, and the conductive agent is selected from at least one of conductive carbon black, carbon fiber, graphene and a carbon nanotube; the binder is selected from at least one of polytetrafluoroethylene, an ethylene-tetrafluoroethylene copolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, polyvinylidene fluoride and polyoxyethylene; the lithium supplementing layer comprises lithium metal and / or lithium alloy. The lithium supplement composite layer meets the above characteristics, lithium supplement is carried out on the negative pole piece, the first coulombic efficiency of the secondary battery can be improved, the cycle capacity attenuation is reduced, and the energy density of the secondary battery is improved.

The invention provides a preparation method of a hyperbranched polyimide-derived silicon-carbon negative electrode material, which comprises the following steps: S1, preparation of a carbon precursor: mixing 1, 3, 5-tris (4-aminophenyl) benzene and 4, 4 '-(hexafluoroisopropenyl) diphthalic anhydride for reaction to prepare hyperbranched polyimide; s2, preparing porous carbon; and S3, vapor phase silicon carbon deposition. The invention also correspondingly provides a silicon-carbon negative electrode, a lithium ion battery and an electrochemical device. According to the hyperbranched polyimide-derived silicon-carbon negative electrode material, the volume expansion of silicon in the lithium intercalation process is effectively relieved, the active material is prevented from falling off, and the cycling stability of the battery is improved.

The invention provides a graphite composite material, a preparation method thereof and a secondary battery, and relates to the technical field of lithium ion battery negative electrode materials. The graphite composite material comprises an inner core and a shell layer, the inner core comprises metal element doped metal oxide and graphite, the metal element doped metal oxide is embedded between sheet layers of the graphite, the shell layer comprises multi-walled carbon nanotubes and amorphous carbon, and the multi-walled carbon nanotubes are distributed in the amorphous carbon in a 3D net shape. According to the invention, by introducing the doping element, the lithium intercalation active sites of the metal oxide are increased, so that the lithium storage performance of the graphite composite material is improved; through the construction of a core-shell and intercalation structure, the volume expansion of the metal oxide is inhibited, so that the cycling stability of the graphite composite material is improved.

The invention provides a silicon-based composite material, a preparation method thereof and a negative plate. The silicon-based composite material comprises silicon-based composite material particles, the silicon-based composite material particles comprise a porous substrate and silicon particles loaded in pores of the porous substrate, the silicon particles comprise at least one silicon nanoparticle and an oxygen-enriched layer at least partially coating the silicon nanoparticle, the oxygen-enriched layer is made of SiOx, x is more than 0 and less than or equal to 2, and x is more than 0 and less than or equal to 2. And the oxygen content in the oxygen-rich layer is in gradient change along the direction from the center to the surface of the silicon nanoparticle. According to the silicon-based composite material provided by the invention, the plurality of silicon particles taking the silicon nanoparticles as the core and the oxygen-enriched layer as the shell are loaded on the porous substrate, and the oxygen content in the oxygen-enriched layer is in gradient change, so that the conductivity of the silicon-based composite material is improved; moreover, the volume expansion of silicon in the lithium intercalation process can be relieved by utilizing the oxygen-enriched layer with the gradient change of the oxygen content, the expansion rate of the electrode is reduced, and the cycle performance of the battery is further improved.

A hard carbon material, having a first characteristic peak from 15° to 35° and a second characteristic peak from 25° to 28° in an X-ray diffraction pattern of the hard carbon material. A starting position of the first characteristic peak is A°, an ending position of the first characteristic peak is B°, and B−A≥8°. A peak intensity of the first characteristic peak is I1, a peak intensity of the second characteristic peak is I2, and 0.1≤I2 / I1≤3.0. When a negative electrode plate prepared using the hard carbon material as an active material is subjected to charge and discharge test with lithium metal as a counter electrode to obtain a differential capacity curve, the negative electrode plate has four reversible lithium intercalation peaks and three or four reversible lithium deintercalation peaks within a voltage range of 0 V to 0.4 V.

The invention discloses a positive plate and a preparation method thereof, a lithium ion battery and a power utilization device, the positive plate is provided with a middle area and at least one outer side area located at the periphery of the middle area, and the polarizability of the middle area is greater than that of the outer side area. The polarizability of the middle area of the positive plate is greater than that of the outer area, so that the phenomena of high temperature, large expansive force and small polarization of the middle part of the pole plate, low temperature, small expansive force and large polarization of the head part and the bottom part of the pole plate due to the influence of heat dissipation in a battery cell circulation process are counteracted, and the polarizability uniformity of the middle area and the outer area of the pole plate is improved; the problem that the lithium intercalation amount in the outer side area of the pole piece is lower than that in the middle area is solved, and the problem of lithium precipitation in the middle of a battery cell is solved.

The invention provides a three-dimensional conductive binder, a negative plate, a secondary battery and a preparation method, and relates to the technical field of secondary batteries, the three-dimensional conductive binder comprises a high-molecular polymer and a carbon-based conductive agent; the high-molecular polymer comprises polyesteramide; the polyesteramide has a three-dimensional bonding network; the polyesteramide is prepared from polyamide acid and polyhydric alcohol through vacuum in-situ polymerization; the number of hydroxyl groups in the polyhydric alcohol is 3 to 6; the number of carbon atoms between hydroxyl groups at two ends of the polyol is 3-8; the carbon-based conductive agent is grafted on the polyesteramide through a chemical bond. According to the three-dimensional conductive binder provided by the invention, the volume effect of the silicon-based material in the lithium intercalation process is bound through the effects of hydrogen bonds and the like, so that the expansion of the silicon-based negative electrode material is effectively inhibited, and the cycle performance of the battery is improved.

The invention discloses a lithium ion battery fault diagnosis method based on lithium plating detection, comprising the following steps: obtaining data such as battery thickness increment, battery temperature, ambient temperature, charge and the like through experiments; establishing a basic model for battery lithium plating layer detection, a thermal expansion compensation model and a lithium embedding expansion compensation model; adding pressure measuring points to repeat the experiment and establishing a gasification expansion compensation model; establishing a lithium ion battery lithium plating layer detection model; inputting the real-time measured battery temperature and ambient temperature, charge and battery thickness increment into each compensation model to obtain a corresponding thickness compensation value, subtracting the thickness compensation values ​​of thermal expansion, lithium embedding expansion and gasification expansion from the real-time measured battery thickness increment value to obtain a basic lithium plating layer thickness value approximately measured in real time; establishing a lithium ion battery lithium plating layer thickness detection estimator, detecting the lithium plating layer thickness online according to the real-time measured battery thickness, ambient temperature, battery temperature and charge and the like data, and performing lithium plating fault diagnosis.

The invention provides a modified silicon-based negative electrode material, a preparation method thereof and a lithium ion battery containing the modified silicon-based negative electrode material. The modified silicon-based negative electrode material comprises an inner core and a carbon coating layer coating the inner core, the chemical formula of the inner core is AaEeMmSiOx; the element A is selected from Li, Na, K, Rb and Cs; the element E is selected from the group consisting of Be, Mg, Ca, Sr and Ba; element M is selected from the group consisting of B, Al, Ga, In, Tl, Ge, Sn, Pb, N, P, As, Sb, Bi, S, Se, Te, F, Cl, Br, and I. The modified silicon-based negative electrode material provided by the invention has good electronic conductivity and ionic conductivity, can inhibit the side reaction of lithium and silicon during lithium intercalation, is stable in structure, and can improve the first effect, rate capability and cycling stability of the lithium ion battery at the same time when being applied to the lithium ion battery.

The invention provides a sandwich structure MCMB-Si-C silicon-carbon negative electrode material and a preparation method and application thereof.The preparation method comprises the steps that 1, pitch serves as a raw material to prepare mesocarbon microbeads, by means of solid-liquid interface pushing force in the mesocarbon microbead growth process, uniform attachment of nanometer silicon to the surfaces of the mesocarbon microbeads is achieved through a one-step self-assembly method, and the mesocarbon microbeads are formed; the MCMB (at) Si silicon-carbon negative electrode material taking the mesocarbon microbeads as the core is obtained. And (2) coating the surface of the silicon-carbon negative electrode material with a layer of carbon material to construct the MCMB-Si-C silicon-carbon negative electrode material with a sandwich structure, and forming a compact carbon layer on the outermost layer after high-temperature carbonization treatment by using a liquid-phase coating process, so that the double functions of a buffer layer and a conductive layer can be achieved. The composite material is composed of mesocarbon microbeads as a core, nano silicon as an intermediate layer and a compact carbon layer as an outermost layer. The sandwich type buffer structure effectively improves the volume change of the negative electrode in the lithium intercalation / lithium removal process, endows the silicon-carbon negative electrode material with the sandwich structure with excellent cycle stability and rate capability, and is beneficial to formation of a more stable solid electrolyte membrane.

The invention discloses a high-cycle-performance aqueous battery, which comprises an aqueous electrolyte, a negative electrode, a first positive electrode and a second positive electrode, wherein the first positive electrode and the second positive electrode are positioned on two sides of the negative electrode, and a first diaphragm and a second diaphragm are respectively arranged between the first positive electrode and the negative electrode and between the second positive electrode and the negative electrode; the battery is provided with an electromagnetic valve, the electromagnetic valve is electrically connected with the first positive electrode and the second positive electrode to control switching of the positive electrodes in the charging and discharging loop, and every time discharging and charging circulation are completed, the electromagnetic valve switches the electrode connection relation, and the first positive electrode and the second positive electrode are alternately connected into the charging and discharging loop. Switching of the two positive electrodes in the aqueous battery is accurately controlled through the electromagnetic valve, a positive-negative battery structure is formed in real time, the double positive electrodes alternately perform lithium removal-lithium intercalation reaction, excessive Li intercalation or insufficient positive electrode reduction caused by long-term charging and discharging of a single positive electrode is avoided, the structural stability of the positive electrode material is improved, and the service life of the battery is prolonged. The cycle life and the electrochemical performance stability of the aqueous battery are obviously improved.

The invention belongs to the related technical field of semiconductor devices, and discloses an edge contact type field effect transistor and a preparation method thereof.The transistor comprises a substrate layer and a gate layer arranged on the surface of the substrate layer in a protruding mode, and a channel layer is arranged above the gate layer; the channel layer strides over the gate layer and is provided with a channel region located over the gate layer, two electrode regions located on the two opposite sides of the gate layer and a rising region connected between the electrode regions and the channel region, the channel layer is made of transition metal chalcogenide, and the electrode regions are used for conducting induced phase change through a lithium embedding method; therefore, edge contact of the metal phase and the semiconductor phase is realized. According to the invention, lithium embedding is limited by utilizing stress, and local stress is additionally introduced into the channel layer by utilizing a step formed by the gate layer and the substrate layer, so that the diffusion behavior of lithium ions is blocked and limited at a stress existence position, namely a rising region, preparation of a sharper phase transformation interface can be realized, and the method has high consistency and is convenient for large-scale integration.

The invention relates to the technical field of batteries, in particular to a silicon-carbon composite material and application thereof. The silicon-carbon composite material comprises a porous carbon material and nano silicon particles positioned in pores of the porous carbon material, in a dQ / dV curve of lithium intercalation for the first time of the silicon-carbon composite material, the ratio of the intensity value of a lithium intercalation peak at 0.30-0.45 V to the strongest peak value within 0-0.25 V is less than 0.05. The silicon-carbon composite material has the advantages of high compressive strength, high charge-discharge capacity and good cycle stability.

The invention relates to a negative electrode material and a preparation method thereof, and a lithium ion battery, the negative electrode material comprises a carbon matrix and an active substance, the carbon matrix has pores, and at least part of the active substance is distributed in the pores of the carbon matrix. The carbon dioxide in the pores of the carbon matrix in the negative electrode material can be quickly dissolved in the electrolyte and promote the electrolyte to enter the pores of the negative electrode material, and meanwhile, in the lithium intercalation process, the dissolved carbon dioxide can reduce the decomposition rate of FEC and reduce the formation of a loose and irregular SEI film, so that the lithium intercalation efficiency is improved. And the binding effect of fluorine in the lithium fluoride SEI film and lithium in the lithium silicon alloy is improved, so that the capacity and the first effect of the negative electrode material are improved.

The invention discloses a silicon-carbon composite material containing a covalent organic framework material coating layer for a negative electrode of a lithium ion battery and a preparation method of the silicon-carbon composite material. The silicon-carbon composite material containing the covalent organic framework material coating layer comprises a silicon-based / porous carbon composite material and the covalent organic framework material coating layer coating the surface of the silicon-based / porous carbon composite material, and the covalent organic framework material is a crystalline porous polymer material formed by connecting organic molecules through covalent bonds. The catalyst has the advantages of low specific surface area and good thermal stability, and contains a regular pore channel structure with adjustable pore diameter. The method has the advantages that the volume expansion of the silicon-carbon composite material in the lithium intercalation and deintercalation process is inhibited, and the mechanical property of the silicon-carbon composite material is improved, so that the cycle performance of the material is improved, and the first coulombic efficiency is improved.

The invention relates to the technical field of batteries, in particular to a negative electrode material and a preparation method and application thereof. The negative electrode material comprises a base material and a composite coating layer coated on the surface of the base material, the base material comprises a compound of graphite and hard carbon, the base material has a porous structure, the composite coating layer comprises a first coating layer coated on the surface of the base material and a second coating layer coated on the surface of the first coating layer, the first coating layer includes a carbon material and a conductive agent, and the second coating layer includes a lithium-containing compound. In the negative electrode material provided by the invention, the matrix material comprises the compound of graphite and hard carbon, has abundant porous structures and defects, can increase lithium intercalation channels of lithium ions in particles, and improves the fast charging capability; the composite coating layer can effectively improve defect interface conductivity, reduce overall cross-linking impedance, improve the transmission capacity of Li < + > between carbon layers, promote Li < + > desolvation in SEI and improve the graphite fast charging performance.

The application relates to the technical field of lithium / sodium ion battery negative electrode materials, in particular to a phosphorus-based negative electrode material with a solid electrolyte interface and a preparation method and application thereof, the method comprises the following steps: mixing phosphorus powder, a carbon material and a metal fluoride and performing ball milling to obtain a composite negative electrode material; and performing sieving treatment on the composite negative electrode material to obtain the phosphorus-based negative electrode material. According to the application, the metal fluoride is doped to in-situ construct a solid electrolyte interface with high strength and high lithium ion / electron transmission, so that the cycle stability and the rate performance of the battery are improved. When the lithium ion battery is discharged, the metal fluoride can in-situ construct a solid electrolyte interface rich in fluorinated lithium with high Young's modulus and lithium-metal alloy with high ion / electron conductivity on the surface of phosphorus-carbon particles prior to phosphorus-carbon lithium intercalation, the solid electrolyte interface can enhance the strength of the solid electrolyte interface by means of the fluorinated lithium with high Young's modulus, so as to inhibit the expansion of the phosphorus-carbon negative electrode, and the cycle stability is improved.

The invention discloses a composite carbon-coated graphite negative electrode material and a preparation method and application thereof.The negative electrode material is of a coating structure, an inner core comprises graphite, a coating layer comprises graphitized carbon and hard carbon, the graphitized carbon and the hard carbon are evenly distributed, more lithium intercalation active sites are provided for the surface of the graphite, and meanwhile the surface of the graphite is coated with the composite carbon. And the high-temperature performance deterioration of the material is effectively reduced. According to the negative electrode material, the epoxy asphalt is used as a coating agent raw material, a resin-based component and an asphalt component which exist in the epoxy asphalt at the same time are subjected to carbonization treatment and graphitization treatment to obtain a hard carbon and graphitized carbon composite carbon coating layer which is uniformly distributed, and compared with coating of hard carbon or soft carbon, the composite carbon coating layer has the advantages that the coating effect is good; and the material has excellent quick-charging performance and good high-temperature performance. When the lithium ion battery electrolyte is applied to a lithium ion battery, the dynamic performance test shows that lithium is not separated out or slightly separated out, and the electrolyte has excellent fast charging performance; the capacity recovery rate can reach 80.3-91.9% after being stored for 100 days at the high temperature of 60 DEG C, and the high-temperature performance is good.

Disclosed in the present application is a method for extracting lithium from salt lake by means of electrochemical deintercalation. The method comprises the following steps: (1) separately injecting a recovery liquid into an anode chamber and injecting salt lake brine into a cathode chamber, isolating same by using an anion exchange membrane, and performing a constant-voltage reaction using a lithium-rich electrode as an anode and a lithium-poor electrode as a cathode; (2) when the current density of the constant-voltage reaction is reduced to 30-40 A / m2, injecting a highly-reductive gas into the salt lake brine; and (3) when the current density is reduced to 5 A / m2, powering same off to stop the reaction, exchanging the cathode and the anode, and repeating the constant-voltage reaction, so as to obtain a lithium-rich solution. The present application introduces the reductive gas into the brine at the cathode, so as to improve the lithium intercalation rate of the cathode, thus sufficiently ensuring the adsorption capacity of electrodes and avoiding the problem of capacity attenuation during cyclic lithium extraction processes.

The invention relates to a composite negative electrode material and a preparation method thereof and a battery, the composite negative electrode material comprises a carbon material and a silicon-based material, the carbon material is provided with holes, the aperture of at least part of the holes is gradually reduced from the surface of the carbon material to the inside, and at least part of the silicon-based material is filled in the holes. And the opening porosity of holes in the composite negative electrode material is 2-20%. According to the composite negative electrode material disclosed by the invention, the silicon-based material is filled in the holes of the carbon material, so that the structural stability of the material can be improved, the collapse of the material structure caused by volume expansion in the lithium intercalation and deintercalation process is reduced, and the occurrence of side reactions is effectively reduced, thereby improving the cycle performance of the material.

The internal temperature distribution of a battery cell is assessed by acquiring lithium content at different positions on a negative electrode plate of a target battery cell and a corresponding test environment temperature and determining lithium intercalation reaction rate ratios at different positions based on the lithium content at different positions on the negative electrode plate. Temperature values at different positions on the negative electrode plate are calculated based on the lithium intercalation reaction rate ratios at different positions on the negative electrode plate and the test environment temperature. An internal temperature distribution assessment result of the target battery cell is determined based on the temperature values at different positions on the negative electrode plate. Temperature gradients at different positions can be calculated by measuring the lithium content on a lithium-intercalated negative electrode plate, so that the internal temperature distribution assessment result of the battery cell can be obtained.

The invention belongs to the technical field of battery materials, and discloses a pre-lithiated silicon negative electrode, a preparation method thereof and an all-solid-state battery. The pre-lithiated silicon negative electrode sequentially comprises a foamed nickel substrate, a lithium intercalation body layer and a lithium source layer from bottom to top, and components in a lithium intercalation body permeate into pores of the foamed nickel substrate. Through the interaction of the foamed nickel substrate, the lithium source layer and the lithium intercalation body layer, the pre-lithiated silicon negative electrode can more effectively intercalate and deintercalate lithium ions in the first charge-discharge cycle, the first coulombic efficiency of the battery is remarkably improved, and the waste of the lithium source is reduced; and the stress caused by volume expansion of silicon is also relieved, so that the cycling stability of the pre-lithiated silicon negative electrode is enhanced.

The invention provides a lithium ion battery and a power utilization device, the lithium ion battery comprises a positive plate, the positive plate comprises a positive current collector and a positive active material coated on at least one surface of the positive current collector, and the positive active material at least comprises one secondary sphere particle; the diameter of the secondary spherical particles is D, the secondary spherical particles are divided into a region A and a region B in the three-dimensional space, the region A is a spherical region with the center of the secondary spherical particles as the sphere center and the diameter is m, m is equal to 0.382 D, and the region B is the part, except the region A, of the secondary spherical particles; the order degree of the area A and the area B meets the condition that RA is smaller than RB. Secondary sphere particles are divided into a region A and a region B, RB is set to be greater than RA, the region B with high order degree is easier to form a lithium ion channel, the lithium intercalation performance is improved, lithium ions in an electrolyte preferentially contact the region B and are rapidly and orderly introduced through the lithium ion channel, and the rate capability of the battery is improved; the area A is used for improving the structural stability and guaranteeing the cycle performance of the battery.

The invention belongs to the technical field of lithium battery waste recovery, and particularly relates to a method for extracting a lithium element from a waste battery. According to the method, the waste battery is charged firstly, so that lithium is gathered to the negative electrode graphite, the lithium is embedded into the graphite, then crushing treatment is carried out underwater, heat is absorbed through a large amount of water to isolate oxygen, and the thermal runaway phenomenon caused by electrification in the crushing process is avoided; during crushing, the graphite negative electrode can be desorbed into water from a pole piece, and the graphite negative electrode is separated out and lithium ions embedded in the graphite negative electrode are brought out in a froth flotation manner by utilizing the hydrophobicity of graphite; and subsequently, acid liquor is used for recycling the lithium element through leaching. According to the method disclosed by the invention, most lithium is recovered by adopting a mode of pre-extraction and small part of lithium is subjected to post-extraction, the pure lithium element is preferentially extracted in a simple mode, and the condition of lithium loss caused by post-extraction of lithium is reduced; and the raffinate is recycled, so that the consumption of other materials is reduced while the lithium recovery rate is increased. The method is simple, and the recovery rate of lithium is high.

The embodiment of the invention discloses a negative electrode and a preparation method thereof and a battery, the negative electrode comprises a silica material, a first material and a binder, the first material comprises MXene of a lithium intercalation layer and an elastic polymer electrolyte coating layer coating the surface of the MXene of the lithium intercalation layer, and a three-dimensional elastic network with ionic conductivity is constructed by adhering a binder to the periphery of the silica material. Under the combined action of the network and MXene particles of a rigid lithium intercalation dispersed in the network, the huge volume expansion of the silica material in the circulation process can be effectively bound and buffered, and the integrity and stability of the electrode structure are maintained. Meanwhile, the elastic polymer electrolyte is used as an ionic conductor, so that an additional path is provided for storage and transmission of lithium ions in lithium intercalation MXene; and meanwhile, the MXene of the lithium intercalation layer can also be used as a lithium supplementing material, so that the first coulombic efficiency of the battery is effectively improved.

A battery that cycles lithium ions includes a negative electrode, a positive electrode spaced apart from the negative electrode, and a gel polymer electrolyte disposed between and configured to provide a medium for the conduction of lithium ions between the negative electrode and the positive electrode. The positive electrode includes a high-voltage electroactive material formulated to undergo lithium intercalation and deintercalation. The gel polymer electrolyte includes an aliphatic polyester, a lithium salt, and an ionic liquid. The aliphatic polyester includes a substituted or unsubstituted poly(ethylene carbonate) (PEC). The lithium salt includes lithium sulfonylimide, lithium borate, or a combination thereof. The ionic liquid includes substantially equimolar amounts of a cation and an anion, with the cation including a complex of lithium (Li+) and an ethylene glycol dimethyl ether, an imidazole ion, or a combination thereof, and the anion including a sulfinate ion, a borate ion, or a combination thereof.