2367 results about "Lithium metal" patented technology

The invention discloses a phosphonic acid-based metal organic framework solid electrolyte as well as a preparation method and application thereof, and belongs to the technical field of solid electrolyte materials. The method comprises the following steps: mixing a metal salt, an organic phosphonic acid ligand and an organic solvent, carrying out a coordination reaction, and treating to obtain MOF powder; heating and activating the MOF powder to obtain activated MOF powder; the method comprises the following steps: mechanically grinding lithium salt and MOF powder to form a mixture, heating to enable the molten lithium salt to permeate and fill MOF channels, and cooling to obtain solid electrolyte powder. The ionic conductivity of the solid electrolyte at 30 DEG C reaches 1.01 * 10 <-4 > S cm <-1 >, and the solid electrolyte is kept stable in a 4.4 V high-voltage window. The symmetrical battery based on the phosphonic acid-based MOF solid electrolyte can stably operate, and shows excellent compatibility and stability of the electrolyte and a lithium metal negative electrode. The method has the advantages of simple operation, cheap and easily available components, and is expected to be suitable for large-scale preparation.

The embodiment of the invention provides a synthesis method and application of lithium sulfide. The synthesis method of the lithium sulfide comprises the following steps: providing a sulfur source and a lithium source; performing first treatment on the sulfur source to obtain sulfur vapor; performing second treatment on the lithium source to obtain molten metal lithium; and in an inert atmosphere, introducing the sulfur vapor into the molten metal lithium, and reacting to generate lithium sulfide. According to the synthesis method and application of the lithium sulfide provided by the embodiment of the invention, the sulfur source is converted into the sulfur vapor, the lithium source is converted into the molten metal lithium, and the gas-liquid out-phase reaction is carried out in the inert atmosphere, so that the reaction efficiency and the purity are improved, the process is simplified, the cost is reduced, and the high-purity requirement can be met; the purity can be improved through raw material pretreatment of sulfur steam and molten metal lithium, and the strict requirement of a solid-state battery for high-purity lithium sulfide is met.

The invention belongs to the technical field of solid-state battery materials, and discloses an inorganic solid-state electrolyte lanthanum lithium zirconate surface interface non-metallic element doped modified material using a plasma technology and a preparation method and application thereof, which can reduce the interface impedance of an electrolyte and improve the electrochemical performance of the electrolyte. By using the plasma technology, impurities such as lithium carbonate and the like on the surface of the inorganic solid electrolyte lanthanum lithium zirconate can be etched, a lithium-loving protective layer can be generated in situ on a surface interface, and the air stability of the electrolyte block is improved. According to the invention, multi-aspect modification can be realized by combining a plasma technology with a plurality of non-metallic element excitation sources, corresponding gain protection layers can be formed according to different requirements, and performance exertion of the battery in different fields is facilitated. When the inorganic solid electrolyte lanthanum lithium zirconate modified material obtained by the method disclosed by the invention is in contact with lithium metal to form a battery, the inorganic solid electrolyte lanthanum lithium zirconate modified material shows relatively low interface contact resistance and excellent cycling stability, and has a good application value.

The invention relates to an integrated carbonaceous honeycomb framework lithium metal composite negative electrode and a preparation method thereof, and belongs to the technical field of lithium metal batteries, the integrated carbonaceous honeycomb framework lithium metal composite negative electrode is formed by depositing lithium metal in an integrated carbonaceous honeycomb framework host, and the host is constructed by adopting metal salt-colloidal crystal microsphere template precursor preparation, compression molding and controllable carbonization processes. The structure has a highly ordered three-dimensional integrated macroporous skeleton, and can realize rapid transmission and uniform electric field distribution of lithium ions and electrons, so that dendrite-free homogeneous lithium deposition under ultrahigh capacity is realized, volume expansion is remarkably inhibited, and the reversible stability of lithium metal deposition / stripping is improved. The invention provides an efficient and stable negative electrode solution for a high-energy-density lithium battery, and has an important application prospect.

The invention relates to the field of lithium metal batteries, and provides a lithium metal battery, a manufacturing method thereof and electric equipment, which are at least beneficial to improving the interface stability and safety of the lithium metal battery. The manufacturing method comprises the following steps: preparing an initial battery cell, injecting a first electrolyte into the initial battery cell, and then carrying out a first formation process, the first electrolyte comprising the following components: 8-23 wt% of a lithium salt, 0.01-5 wt% of carbon dots, 0.1-10 wt% of lithium nitrate and an ether solvent; a second formation process is carried out after a second electrolyte is injected into the initial battery cell, the second electrolyte comprises the following components: 8-23 wt% of a lithium salt, 5-40 wt% of a film-forming additive and an ionic liquid, and the ionic liquid comprises pyrrolidinium cations.

The invention discloses a sulfide-based composite solid-state electrolyte, a preparation method thereof and a lithium metal solid-state battery, sulfide is subjected to specific bifunctional surface grafting modification by using a silane coupling reagent with sulfydryl and epoxy bonds, then the sulfide is introduced into a polymer precursor liquid, and the sulfide-based composite solid-state electrolyte is prepared through light-heat curing reaction synergy. A flexible and rigid cross-linked network is formed, the sulfide-based composite solid-state electrolyte with high ionic conductivity and high mechanical strength is obtained, the interface stability of the sulfide-based composite solid-state electrolyte in the charge-discharge process is ensured, for example, the sulfide-based composite solid-state electrolyte in the embodiment 1 has high ionic conductivity (3.81 mS / cm), and the interface stability of the sulfide-based composite solid-state electrolyte in the embodiment 2 is ensured. The lithium-lithium symmetric battery prepared by the method has the advantages of excellent flexibility, high tensile strength (7.9 Mpa) and wide electrochemical window (5.1 V), the lithium-lithium symmetric battery can stably circulate for 2000h, and the whole battery can stably circulate for 2000 circles at the room temperature at the rate of 4C, so that the lithium-lithium symmetric battery has great industrial application value.

The invention discloses an oxyhalide solid electrolyte, a preparation method thereof and an all-solid-state battery, and relates to the technical field of batteries. The solid electrolyte is LiaMbNcXdOe, M and N are the same elements or different elements, and M and N are at least one of Zn, Ba, Al, In, Y, Cr, Ti, Zr, Hf, Nb, Ta, La, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; x is at least one of F, Cl, Br and I. The oxyhalide solid electrolyte with high ionic conductivity and cost advantage is prepared by selecting high-valence metal oxide, halide and lithium halide through a ball milling method and combining annealing and hot pressing processes, and the oxyhalide solid electrolyte can show good electrochemical performance when being applied to all-solid-state lithium metal batteries.

The present invention relates to a high-voltage lithium metal battery, characterized by its non-flammability due to the high flash point and high thermal stability of its specifically designed electrolyte, thereby ensuring its safe operation. In particular, the battery comprises an electrolyte with lithium salts and a novel diether compound with asymmetrical fluorination, developed based on electrolyte molecular design, synthesis and thermophysical properties characterization. The electrolyte with the asymmetrically fluorinated diether compound exhibits high thermal stability through high boiling point and high flash point, while also having a high working voltage, allowing high energy density designs and simultaneously optimizing operation safety by minimizing flammability and flash risks.

The invention discloses a mixed ion conductor layer for a lithium metal negative electrode, a preparation method of the mixed ion conductor layer and an all-solid-state battery, and belongs to the technical field of sulfide all-solid-state batteries. The preparation method comprises the following steps: synthesizing a sulfide electrolyte 70 (0.75 Li2S-0.25 P2S5)-30LiI through a liquid phase, introducing graphene oxide and a lithium salt precursor 2, 5-dihydroxy-1, 4-benzene diphosphate in the electrolyte preparation process, and carrying out heat treatment and pressing to obtain a mixed ion conductor layer; the graphene oxide can isolate the sulfide electrolyte layer from the lithium metal negative electrode, interface reaction is avoided, and a special porous and interlayer structure provides a transverse growth space for lithium metal deposition. And meanwhile, the lithium diphosphate-based MOF among the graphene layers ensures the rapid movement of lithium ions, enhances the bulk diffusion of lithium at the negative electrode end, reduces the local current density, plays a role in dredging the distribution of the lithium ions, and remarkably prolongs the cycle life of the sulfide all-solid-state battery.

The present invention provides a lithium battery cathode additive and its application in the preparation of high-energy batteries. The invention proposes for the first time the use of 1-azaphenolthiazine as a lithium battery cathode additive. 1-azaphenolthiazine has high solubility in NMP solvent and small molecule properties, enabling interface modification of the cathode within existing lithium-ion battery manufacturing processes, thereby imparting high voltage stability and full-charge float charge resistance to the lithium battery. The high-energy lithium battery prepared using this additive utilizes a novel battery structure, effectively addressing the problem of easily broken lithium metal anode tabs while achieving high-voltage operation. This improves the cycle stability of 600Wh / kg lithium batteries and demonstrates high engineering application value.

The invention discloses a perfluoropolyether blended PEGDE-based solid electrolyte and a preparation method thereof, and belongs to the technical field of lithium metal battery solid electrolyte materials. Adding SnCl4 and TAA into the nanocellulose precursor solution, stirring, carrying out suction filtration, and drying to obtain a SnS2 (at) NC support layer; and mixing and stirring PEGDE, LiDFOB, LiTFSI and PFPE to obtain PEGDE-based solid electrolyte slurry, coating the SnS < 2 > (at) NC supporting layer with the PEGDE-based solid electrolyte slurry, and performing in-situ polymerization in a drying oven to obtain the PEGDE-based solid electrolyte. The ultrathin perfluoropolyether blended PEGDE-based solid electrolyte prepared based on PEGDE in-situ polymerization and perfluoropolyether blending and in combination with nanocellulose enhancement has the advantages of stable anode interface, high mechanical strength, high decomposition voltage and high ion transference number.

The invention belongs to the related technical field of lithium ion batteries, and discloses a method and a system for predicting dendritic crystal and crack evolution in a solid-state lithium metal battery. The method comprises the following steps: establishing a computational domain of a solid-state lithium metal battery and a pre-cracked solid-state electrolyte, applying stacking pressure and lateral pressure on the computational domain, and performing grid division on a two-dimensional model of the lithium metal battery and the solid-state electrolyte in the computational domain; establishing a multi-physics field model in the two-dimensional model after grid division, wherein the multi-physics field model comprises a dendritic phase field equation, a concentration diffusion equation, a potential field equation, a solid mechanical equation and a crack phase field equation; and combining the multi-physical field model to solve an optimization model with the minimum cracking failure degree of the solid electrolyte as a target, and obtaining the cracking failure degree of the solid electrolyte under different material parameters and working pressures. Through the method, the problems that in the crack evolution process, prediction precision is low and pressure constraint is not optimized due to the fact that micro-scale prediction is not carried out are solved.

The invention relates to a doped modified argyrodite type solid electrolyte and a preparation method thereof, and belongs to the technical field of all-solid-state battery materials. The chemical formula of the electrolyte is Li < 5.5 + 2x + 2y > P < 1-x-y > Y < x > Bi < y > S < 4.5-1.5 x-1.5 y > O < 1.5 x + 1.5 y > Cl < 1.5 >, x is greater than or equal to 0.01 and less than or equal to 0.04, and y is greater than or equal to 0.01 and less than or equal to 0.04; the yttrium element and the bismuth element are doped at the P site of the argyrodite type electrolyte, and the oxygen element is doped at the S site of the argyrodite type electrolyte. After the argyrodite type electrolyte is in contact with metal lithium, an interface protection layer rich in lithium oxide can be formed in situ at an interface in a circulating process, so that lithium can be uniformly deposited, the generation of interface side reaction is inhibited, the interface stability of the argyrodite type electrolyte to a lithium metal negative electrode is improved, and the polarization voltage of a symmetrical battery is reduced; and the cycling stability of the all-solid-state lithium metal battery is enhanced.

A method for manufacturing an anode electrode includes rolling a first aluminum foil layer; annealing the first aluminum foil layer to create a first annealed aluminum foil layer; mechanically bonding a first lithium metal foil layer between an anode current collector and the first annealed aluminum foil layer; and aging the anode electrode to prelithiate the first annealed aluminum foil layer.

The invention relates to a mesoporous LLZO / PVDF-HFP composite solid electrolyte membrane as well as a preparation method and application thereof. The electrolyte membrane comprises a polymer matrix PVDF-HFP and a disordered mesoporous LLZO filler dispersed in the polymer matrix PVDF-HFP, and the mass ratio of LLZO to PVDF-HFP is (1: 7)-(7: 1). The composite membrane is prepared through a solvent exchange-freeze drying method, and the process comprises the following steps: dissolving PVDF-HFP in an organic solvent, adding mesoporous LLZO, stirring to form uniform slurry, coating the slurry, and carrying out solvent exchange and freeze drying treatment to obtain the membrane. The obtained electrolyte membrane is stable in structure and excellent in ionic conductivity, can be applied to a lithium metal battery as a solid electrolyte membrane material, and remarkably improves the cycling stability and rate capability of the battery.

The invention discloses a composite negative electrode material and a preparation method thereof and a lithium battery, the composite negative electrode material provided by the invention comprises a three-dimensional porous carbon material, and a lithium-loving metal and a lithium metal which are loaded on a three-dimensional porous carbon skeleton, and the three-dimensional porous carbon material is prepared by taking a ZIFs precursor as a raw material. The three-dimensional porous carbon material prepared by taking the ZIFs precursor as a raw material has a Zn / N-containing double-doped three-dimensional porous carbon skeleton, so that the problems of poor conductivity, insufficient lithium storage aperture and the like of the existing carbon skeleton are solved; a plurality of lithium-loving metal nanoparticles are loaded on the surface of the carbon skeleton, so that the lithium-loving property and the electron conductivity of the carbon skeleton are further enhanced, the uniform deposition of lithium is facilitated, and the growth of dendrites is inhibited; the porous carbon skeleton limits the lithium deposition space, the doped nanoparticles provide lithium-loving sites to guide uniform nucleation, the dual mechanisms synergistically inhibit dendritic crystal growth, and the safety of the lithium metal negative electrode is improved.

The invention provides a surface treatment method of a lithium metal pole piece. The invention relates to a surface treatment method of a lithium metal pole piece, which comprises the following steps: reacting the lithium metal pole piece in an organic solvent solution of an aromatic hydrocarbon complexing agent in an inert atmosphere, then taking out the lithium metal pole piece, and cleaning; placing the cleaned lithium metal pole piece in reactive gas for reaction to obtain a modified lithium metal pole piece; wherein the aromatic hydrocarbon complexing agent is a complexing agent which can be subjected to a complexing reaction with lithium, and the reactive gas comprises an oxidizing gas. The original inorganic layer with rough surface appearance and non-uniform component distribution of the lithium metal pole piece is changed into the flat lithium-containing inorganic layer, so that the impedance is reduced, and the service life of the battery is prolonged.

The invention relates to the technical field of lithium battery electrolytes, in particular to a preparation method of a polyether-based solid electrolyte and application of the polyether-based solid electrolyte in electrochemical devices such as lithium metal batteries. The polyether-based solid electrolyte material comprises a porous polymer skeleton, a cyclic ether monomer, a copper-based compound, a lithium salt and a plasticizing additive. The preparation method comprises the following steps: loading a copper-based compound into a porous polymer skeleton, adding cyclic ether, lithium salt and the like to carry out in-situ ring opening polymerization, cooperatively constructing a polyether-porous polymer skeleton three-dimensional network structure, and improving the mechanical strength of the electrolyte. Wherein the copper-based compound widens the chain spacing of the porous polymer, and is convenient for the cyclic ether monomer to penetrate into the skeleton; meanwhile, the in-situ ring-opening polymerization of the cyclic ether promotes the close contact between the electrolyte and an electrode, the interface impedance is reduced, and the ionic conductivity is improved. The polyether-based solid electrolyte prepared by the invention can promote stable circulation of a lithium metal battery.

A lithium oxygen electrochemical cell includes an anode that includes lithium metal, a porous oxygen cathode that includes a conductive carbon and aluminum, and an electrolyte.

Described herein are lithium-metal rechargeable electrochemical cells comprising a lithium-metal negative electrode, a positive electrode, and a liquid electrolyte. The liquid electrolyte comprises a core mixture and a diluent. The diluent comprises a fluorinated ether. The core mixture comprises a set of salts and a set of solvents. The set of solvents comprises a pyrrolidinium-containing ionic liquid and a molecular solvent. The molecular solvent is a non-fluorinated ether, for example including but not limited to 1,2-dimethoxyethane. In some examples, the electrolyte further comprises an electrolyte additive, for example including but not limited to tris(trimethylsilyl)phosphate. In some examples, the set of salts comprises one or more imide-containing lithium salts. In some examples, the set of salts comprises lithium bis(fluorosulfonyl)imide and an additional salt and the mole fraction of lithium bis(fluorosulfonyl)imide in the set of salts is 0.5 or greater.

The invention relates to a preparation method of a high-lithium-affinity vinylene covalent organic framework material serving as a lithium metal negative electrode interface protective layer. The method comprises the following steps: firstly, by utilizing a simple hydrothermal synthesis method, taking 1, 3, 5-trimethyl-2, 4, 6-triazine (TMT) and 2, 2-bipyridine-5, 5-diformaldehyde (BPY) as monomers, and carrying out Aldol condensation reaction to synthesize a covalent organic framework material connected by a vinylene bond, which is named as viCOF-bpy; the electrochemical performance of the material is verified by modifying the surface of a copper pole piece with the viCOF-bpy material and then assembling a battery. The lithium-loving group on the material skeleton can promote the migration of lithium ions, and the vinylidene has very strong chemical stability, so that the electrochemical performance of the lithium metal battery can be effectively improved.

Disclosed are an ionic liquid-based perfluorinated high-voltage-resistant lithium battery electrolyte and a preparation method therefor. The high-voltage-resistant electrolyte is composed of an imidazolyl ionic liquid, a lithium salt, and an electrolyte additive. The ionic liquid-based electrolyte has relatively reversible and stable lithium stripping / deposition performance, exhibits good compatibility with a lithium metal / graphite negative electrode, and can also form a highly fluorinated stable electrode-electrolyte interface (CEI / SEI layer), thus improving the compatibility of the ionic liquid electrolyte with a high-voltage lithium cobaltate positive electrode, and effectively inhibiting dendrite formation and oxidation dissolution of the electrolyte, thereby achieving extremely high cycle stability and Coulombic efficiency of a lithium battery under high voltage conditions.

The invention relates to the field of new energy batteries, in particular to a negative electrode current collector and a preparation method thereof, a pole piece and a battery, and the preparation method comprises the following steps: preparing a carbon nanotube with a hydroxyl group on the surface; mixing a carbon nanotube with hydroxyl on the surface, an isocyanate raw material, diol, water and a second organic solvent, and carrying out heating reflux treatment to obtain a third product; mixing the third product, a polytetrahydrofuran raw material, a second organic solvent and a second ammonium salt, and carrying out a polymerization reaction to obtain a precipitate; carrying out drying treatment on the precipitate, so as to obtain foam polyurethane modified by the carbon nano tube; and taking the foam polyurethane modified by the carbon nano tube as a working electrode, carrying out deposition reaction on the working electrode to obtain a base material with a metal layer deposited on the surface, and washing and drying the base material with the metal layer deposited on the surface. The negative electrode current collector lithium metal battery provided by the invention has relatively large energy density, relatively small battery internal resistance, relatively strong cycle performance and relatively low safety risk.

The invention relates to the technical field of batteries, in particular to a composite positive electrode material, a preparation method thereof and a battery. The composite positive electrode material comprises a positive electrode substrate, a fast ion conductor layer and a halide layer, the positive electrode substrate comprises a doped lithium cobalt oxide material; the fast ion conductor layer is positioned on the surface of the positive electrode substrate and comprises an oxide of a metal element Q with a spinel phase; the halide layer is located on the surface of the fast ion conductor layer and comprises element lithium, metal element M and halogen X. Through coordination and cooperation of the matrix material, the fast ion conductor layer and the halide layer, the structural stability and the surface morphology of the material can be effectively improved, the defects of the material are overcome, and the composite positive electrode material has excellent conductivity and has excellent cycling stability and rate capability at high temperature and / or high voltage, so that the battery has high safety performance.

The invention relates to the technical field of inorganic material preparation and new energy materials, and particularly discloses a lithium metal battery composite solid electrolyte as well as a preparation method and application thereof. Lithium niobate with high lithium ion conductivity and high dielectric constant is used as an inorganic filler, polyvinylidene fluoride-co-hexafluoropropylene is used as a polymer matrix, and the lithium metal battery composite solid electrolyte is prepared. The lithium metal battery solid electrolyte with a continuous lithium ion transport path is constructed through a freeze casting technology, the dielectric constant of the solid electrolyte is effectively improved by adding the dielectric inorganic filler lithium niobate, lithium salt dissociation is promoted, preparation of the modified electrolyte can be simply completed on a large scale, industrial expansion is facilitated, coulombic efficiency is improved, and the lithium metal battery solid electrolyte is suitable for industrial production. According to the present invention, the lithium metal battery electrolyte meets the industrial requirement on the high lithium utilization rate, the lithium negative electrode can be well protected, the cycle life of the lithium electrode can be improved, the battery electrolyte and the lithium electrode show the good interface compatibility and the good cycle stability, and the new feasible way is provided for the application of the lithium metal battery.

The invention discloses a preparation method and application of a positive electrode lithium supplement agent, the positive electrode lithium supplement agent is of a core-shell structure, and a core layer comprises lithium-rich metal materials such as lithium-rich lithium ferrite, lithium-rich lithium nickelate and lithium-rich lithium manganate; and a shell layer comprises organic lithium salt materials such as lithium bis (oxalato) borate, lithium bis (fluorosulfonyl) imide, lithium difluorophosphate and lithium difluorobis (oxalato) phosphate. The lithium-rich metal material lithium supplementing agent is coated with the organic lithium salt lithium supplementing agent which is also used as the lithium supplementing agent, so that the lithium-rich metal material is prevented from being in contact with air, and the environmental stability of the lithium-rich metal material is improved; through chelation of specific groups and transition metal ions, the structural stability of the lithium-rich metal material is improved, a lithium ion transmission path is fixed, the capacity of the lithium supplement agent for the lithium-rich metal material can be exerted to the maximum extent, and the organic lithium salt also has a lithium supplement effect, so that the migration rate of lithium ions can be further improved, and the lithium supplement effect is improved. The lithium supplementing effect of the two lithium supplementing agents greatly improves the energy density and the cycling stability of the battery.

The invention discloses a lithium metal battery eutectic gel electrolyte and a preparation method and application thereof, and belongs to the field of solid electrolyte. The eutectic gel electrolyte is prepared by carrying out a photocuring reaction on a photocuring precursor solution containing a photoinitiator, and the photocuring precursor solution contains a bi-component liquid compound and a deep eutectic solvent; the two-component liquid compound comprises 4-acryloyl morpholine and a photocurable polyethylene glycol derivative; the deep eutectic solvent is formed from a liquid mixture comprising succinonitrile, lithium bis (trifluoromethylsulfonyl) imide and fluoroethylene carbonate. The eutectic gel electrolyte is composed of a deep eutectic solvent with functional groups such as cyano and sulfonyloxy, and a polymer electrolyte with functional groups such as ether oxygen and a unique skeleton structure. The advantages of high ionic conductivity, wide electrochemical window, high interface stability and the like can be endowed based on the interaction between functional groups and the space confinement effect of a polymer electrolyte skeleton structure.

The invention provides a solid electrolyte membrane, a preparation method thereof and a solid-state battery. The solid electrolyte membrane comprises an inorganic filler, a polymer matrix and a lithium salt, wherein the inorganic filler comprises a dielectric conductive ion material and oxide particles; wherein the dielectric conductive ion material comprises a dielectric filler and a silane coupling agent which is coated on the outer surface of the dielectric filler and contains cyano groups, the dielectric filler contains transition metal elements, and the transition metal elements are Nb elements and / or Ta elements; the oxide particles comprise lanthanum oxide particles; the mass ratio of the dielectric conductive ion material to the oxide particles is (1-5): 1, and the ratio of the total mass of the inorganic filler to the mass of the polymer matrix is (10-50): 100. The solid electrolyte membrane provided by the invention has relatively high ionic conductivity, mechanical strength and structural stability, and can effectively improve the comprehensive performance of the solid lithium metal battery.

The invention belongs to the technical field of lithium metal batteries, and relates to preparation of an ultrathin polymer electrolyte with a wide electrochemical window and application of the ultrathin polymer electrolyte in a solid-state lithium metal battery, a preparation method comprises the following steps: firstly, coating a substrate with polymer slurry, and then soaking, stripping and drying to obtain a porous membrane matrix; the preparation method comprises the following steps: mixing an electrolyte, a conductive lithium salt, a cross-linking agent, 4-fluorine-alpha-methyl styrene and an initiator to obtain an electrolyte precursor solution; and then supporting the electrolyte precursor liquid on the porous membrane substrate, and carrying out in-situ polymerization and curing to obtain the polymer electrolyte. Compared with the prior art, the thickness of the polycarbonate solid electrolyte is 7.8 microns, and the polycarbonate solid electrolyte shows high room-temperature ionic conductivity, a wide electrochemical window and excellent dendritic crystal resistance. And the corresponding 4.5 V high-voltage LiLCO solid-state battery can stably circulate for 1500 circles at room temperature. The electrolyte is ultrathin, the preparation process is simple, the scale is easy to enlarge, and the electrolyte shows a good practical application prospect.

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.