357 results about "Overpotential" patented technology

The invention discloses a preparation method of a modified zinc-bromine flow battery carbon felt negative electrode and the carbon felt negative electrode prepared by the method, and belongs to the field of zinc-bromine flow batteries. According to the method, after the carbon felt is soaked in a mixed solution of cuprous sulfate, water and acetonitrile, the acetonitrile is gradually evaporated from the solution through heating, the cuprous sulfate is gradually subjected to disproportionation reaction, and the copper elementary substance generated by the disproportionation reaction of the cuprous sulfate is deposited on the surface of the carbon felt, so that the purpose of loading the modified carbon felt with the copper elementary substance is achieved. The copper elementary substance is relatively stable in chemical property and has good zinc affinity, and the copper elementary substance is loaded on the surface of the carbon felt, so that the overpotential of zinc nucleation can be reduced, and reaction active sites on the surface of the carbon felt are increased. Besides, relatively strong acting force exists between copper and zinc, so that uniform deposition / stripping of zinc in the charging and discharging process is facilitated, a more uniform zinc deposition layer is formed on the surface of the carbon felt, formation of zinc dendrites is reduced, and the electrochemical performance of the zinc-bromine flow battery is improved.

The invention belongs to the field of electrode materials, and particularly relates to an alkaline hydrogen production electrode and a preparation method thereof.The alkaline hydrogen production electrode comprises an electrode substrate and a catalyst loaded on the electrode substrate; the catalyst comprises the following components: Ni, Fe, Mo, Cr and Mn, the molar percentage of Mo is 5-15%, and the total molar percentage of Fe and Mo is 35%. By alloying, introducing Mo and controlling the content of Fe and Mo, the catalytic activity is enhanced, compared with existing binary Raney nickel, the catalytic activity is higher, the HER reaction overpotential can be effectively reduced, so that the energy consumption of an electrolytic bath is reduced, and the corrosion resistance of an electrode can be enhanced through Cr and Mn.

The invention relates to the technical field of sodium ion batteries, and discloses a low-overpotential uniform sodium deposition composite electrolyte and a preparation method of a sodium metal battery, the composite electrolyte comprises a sodium salt, a solvent, a film-forming additive and a sodium deposition regulating agent; the film forming additive is selected from at least one of NaPO2F2, NaDFOB and Na2SO3; the sodium deposition regulating agent is selected from at least one of CsTFSI, SnCl2 and Bi (OTf) 3. Through the synergistic effect of the film-forming additive and the sodium deposition regulating agent, a stable and firm SEI film can be formed on the interface of the negative electrode current collector, the overpotential of sodium deposition is obviously reduced to 20 mV or below, the growth of sodium dendrites is effectively inhibited, and dense and uniform deposition of sodium is realized. The negative-electrode-free sodium metal battery based on the composite electrolyte shows high first efficiency (greater than or equal to 90%), high coulombic efficiency (greater than 99.5%) and excellent cycling stability, and an effective scheme is provided for solving the core challenge of a sodium metal negative electrode.

The invention discloses a composite cathode and anode plate made of a lead-carbon composite material, the composite cathode and anode plate comprises a current collector, a transition layer and an active layer which are compounded in sequence, the transition layer tightly coats the outer surface of the current collector, the active layer tightly coats the outer surface of the transition layer, and the composite cathode and anode plate is prepared by the following method: S1, preparing the composite cathode and anode plate; raw material pretreatment: placing the carbon material in a vacuum oven; according to the invention, the structural design of the composite negative plate and the preparation process are integrated, so that accurate matching of the raw material ratio and the process parameters is realized, and many defects of the traditional electrode are effectively solved; the three-layer gradient structure improves the interface bonding force, and delamination is avoided; the optimized raw material system and the preparation process have a synergistic effect, so that the hydrogen evolution overpotential is remarkably improved, the internal resistance is reduced, the cycle life is prolonged, the low-temperature performance is improved, the energy density is improved, and a reliable technical scheme is provided for the application of the lead-acid storage battery in the high-end field.

The invention relates to the technical field of fuel cell membrane electrode voltage distribution testing, in particular to a fuel cell membrane electrode voltage distribution testing method and system, and the method comprises the steps: arranging a potential sensor array, and synchronously collecting an original voltage vector through the potential sensor array in the loading operation process of a fuel cell; a reference electrode is arranged in the non-reaction area, a stable reference signal is applied to the reference electrode, and a feedback signal of the reference electrode is collected after preset stable time is delayed; carrying out difference calculation on the feedback signal and the stable reference signal to obtain a system measurement drift distance; and performing joint calibration on the original voltage vector according to the system measurement drift amount and the spatial continuity constraint of the membrane electrode voltage distribution to obtain the voltage distribution vector of the fuel cell membrane electrode. And the authenticity and reliability of the voltage distribution data in the long-period test process of the fuel cell are ensured by continuously compensating the drift of the measurement precision.

A method for determining a condition indicating imminent thermal runaway in a power source includes changing a state of charge of the power source during one of a plurality of charge cycles and a plurality of discharge cycle. In response to the state of charge in each of the one of the plurality of charge cycles and the plurality of discharge cycles, the method includes matching a first condition measuring the state of charge of the power source and determining an overpotential value based on the measured state of charge. The method also includes determining a trend based on a plurality of the overpotential values and identifying an indication of possible thermal runaway in the power source based on the trend indicating a downward trend of the plurality of overpotential values.

The embodiment of the invention provides an electrolyte, a preparation method thereof and an aqueous zinc ion battery, the electrolyte comprises a zinc salt and an electrolyte additive, the electrolyte additive comprises a complex formed by an amine ligand and a reducing metal, and the activity of the reducing metal is weaker than that of zinc. When the electrolyte is applied to the aqueous zinc ion battery, the hydration degree and the deposition overpotential of the zinc ion can be reduced, the reversible reaction can be promoted, and a stable protection layer can be generated on the surface of a zinc negative electrode, so that the zinc dendrite growth and the corrosion side reaction are inhibited, the stability of the zinc negative electrode is improved, and the cycling stability of the aqueous zinc ion battery is improved.

The invention belongs to the technical field of electrochemical energy storage, and discloses a weak-solvation non-aqueous electrolyte as well as a preparation method and application thereof. According to the weak solvation non-aqueous electrolyte, 1-methylimidazole is used as a solvent, and zinc bis (trifluoromethane sulfonimide) is used as a soluble salt. Zn < 2 + > forms a solvation structure of Zn (EMI) 4.99 (TFSI) 1.01 in the electrolyte. Along with the progress of an electrochemical reaction process, TFSIanions are preferentially reduced and decomposed, and an organic-inorganic hybrid double-layer SEI film rich in inorganic components such as ZnF2, ZnS and ZnNx is formed on the surface of a zinc negative electrode, so that the problems of hydrogen evolution side reaction and zinc dendrite existing in an aqueous electrolyte are effectively avoided, and efficient and reversible deposition / stripping of Zn < 2 + > is realized. The zinc ion battery using the electrolyte shows ultra-long cycle life, ultra-low overpotential, high coulombic efficiency and wide temperature adaptability, and a new solution is provided for practical application of the zinc ion battery.

The invention relates to an enzyme-mimic CeO2-based multi-active-site catalyst, a preparation method and application thereof, an electrolytic tank and a battery. CeO2 nanorods are synthesized through hydrothermal and high-temperature pyrolysis methods, and then metal ions are anchored to the surfaces of the CeO2 nanorods through strong interaction of carriers; metal nanoclusters and nanoparticles with specific sizes are synthesized, and then chemical vapor deposition reaction is performed through sodium hypophosphite, so that the bionic nano-enzyme electrocatalyst with multiple active sites is obtained. The multi-active-site catalytic material provided by the invention has high selectivity of ammonia production from nitrate radicals, ammonia production efficiency and Faraday efficiency when being used as a cathode. When the RuO2 is used as an anode, in an alkaline water electrolysis reaction, when the current density is 50 mA / cm < 2 >, the overpotential is 288 mV, which is far better than that of commercial RuO2. Based on excellent oxidation and reduction performance, the zinc nitrate battery has high power density, high ammonia yield and good charge-discharge cycle stability, and nitrate removal, ammonia production and power supply can be achieved at the same time.

This invention discloses a zinc-iodine battery and an electrode carrier that can simultaneously suppress polyiodine ion shuttle and regulate zinc deposition behavior, wherein the electrode carrier is Cu. + Coordinated poly(3,4-ethylenedioxythiophene) (Cu-PEDOT), via a solvothermal method, to convert Cu... + It was prepared by coordinating with S atoms in the PEDOT framework. I₂ was loaded onto this support as the positive electrode, and Zn was electrochemically deposited as the negative electrode to assemble a battery. The atomically monodisperse Cu in this invention... + It not only enhances the chemisorption of polyiodides as a Lewis active site, but also significantly reduces I... ‑ / I 0 Conversion energy barrier, accelerates reaction kinetics and suppresses shuttle effect; at the same time, Cu + The zinc-affinity property of the substrate reduces the Zn nucleation overpotential, guides Zn to deposit uniformly along the (002) crystal plane, and suppresses dendrites. Zinc-iodine batteries based on this substrate exhibit excellent rate performance and ultra-long cycle stability, and achieve dendrite-free negative electrode growth even under high depth-of-discharge conditions. This invention solves the problem of simultaneous multi-iodide shuttle in the positive electrode and zinc dendrite growth in the negative electrode using a single substrate, significantly improving the energy density and cycle life of the battery.

The application provides a preparation method of a large-size tungsten-doped NiFe nanowire electrocatalyst, wherein the foam nickel is immersed in a corrosion solution containing Fe and W for 3-15 minutes to obtain a W-doped NiFe catalyst. The nanometer structure of the catalyst is an ordered nanowire with a diameter of 40-60 nm, and there is no agglomeration phenomenon, which is beneficial to the exposure of active sites and the release of oxygen, and the dense structure can improve the stability of the catalyst. When the W-NiFe catalyst is applied to an oxygen evolution reaction, the overpotential is only 143.7 mV when the current density is 10 mA cm ‑2 , and the catalyst can be stably operated for 150 hours under a current density of 500 mA cm ‑2 . The catalytic performance and stability of the catalyst are superior to those of a noble metal IrO2.

This invention relates to the field of water electrolysis and hydrogen energy utilization technology, and provides an in-situ electrodeposition method for improving NiMoP. x O y A method for studying the catalytic activity and stability of a self-supporting nickel-based hydrogen evolution electrode (NMOP). First, NiMoP... x O y The / NF self-supporting foam nickel-based electrode is prepared by immersing it in a nickel salt solution for a certain period of time, drying it, and then immersing it in a sodium sulfate solution for electrodeposition reduction reaction. This invention provides a simple and convenient method for adjusting the amount of metallic nickel deposited, ensuring its distribution among the active component particles of the electrode. This effectively improves the adhesion of the active component and prevents its detachment, significantly enhancing the hydrogen evolution activity and stability of the hydrogen evolution electrode. At an industrial current density of 100 mA / cm², the overpotential of the modified electrode prepared by this method is reduced by approximately 20% compared to the unmodified electrode, and the charge transfer resistance is reduced by approximately 41%. After 30,000 CV cycle accelerated durability tests, the increases in overpotential and charge transfer resistance are less than 7% and 26% of those of the unmodified electrode, respectively. Therefore, this invention has promising prospects for industrial application.

Low-cost and earth abundant, Ni1-xMox alloy nanocrystals, with sizes ranging from 18-43 nm and varying Mo composition (0.0-11.4%), were produced by a colloidal chemistry method for alkaline HER reactions. For a water splitting current density of −10 mA / cm2, these alloys demonstrate over-potentials of −62 to −177 mV, which are comparable to commercial Pt-based electrocatalysts (−68 to −129 mV). The cubic Ni0.934Mo0.066 alloy nanocrystals exhibit the highest activity as alkaline HER electrocatalysts, outperforming commercial Pt / C (20 wt %) catalyst.

The application provides a modified current collector for self-generating a negative lithium metal battery, and belongs to the technical field of lithium metal batteries. The modified current collector introduces a nanoscale-thickness Ge amorphous thin film on the surface of a copper foil, so that the Ge amorphous thin film is converted into a uniform and dense intermetallic compound layer in situ during the first lithium deposition process, and the alloying speed is fast, thereby significantly reducing the lithium nucleation overpotential, guiding the lithium metal to grow in a high-density and two-dimensional layer shape, and finally obtaining a smooth and dense lithium deposition layer, and greatly improving the cycle stability and safety of the battery.

According to the technical scheme, ultrasonic waves and micron bubbles are applied to electrolytic preparation of copper, the micron bubbles are converted into nano bubbles through the ultrasonic waves, diffusion and transfer processes of active substances in the electrolytic refining process are promoted under the cooperation of the nano bubbles and the ultrasonic waves, the concentration difference of electrolyte is reduced, and the copper content is reduced. The overpotential phenomenon caused by concentration gradient is reduced, the contact area of anode copper and electrolyte is increased, the deposition speed of copper ions on a cathode plate is enhanced and accelerated, the electrolytic efficiency is improved, meanwhile, ultrasonic is matched with nano bubbles to promote the generation of crystal nucleuses and crack normally developed crystals, then grains are refined, and the quality of the product is improved. According to the scheme, preparation of the 4N-grade high-purity copper can be completed through one-time electrolysis, and the production process is simplified.

The invention relates to the technical field of zinc-air batteries, in particular to a preparation method of a NH4Cl auxiliary modified flexible carbon nanotube film loaded nano FeNi particle catalyst, which comprises the following steps: introducing FeNi nanoparticles on an SWCNT film, nitriding by ammonia gas, and decomposing NH4Cl in high-temperature vacuum to generate NH3 and HCl to realize particle in-situ refinement and heterostructure construction. And the FeNi3N / FeNiN active phase with high density and small size is formed. The obtained integrated flexible catalyst has excellent ORR / OER bifunctional activity, the ORR half-wave potential in 0.1 M KOH reaches 0.82 V, the OER overpotential is only 190 mV, and the integrated flexible catalyst has excellent mechanical flexibility and cycling stability and can be directly used as a self-supporting electrode for a high-performance flexible zinc-air battery to promote development of wearable energy devices.

This invention provides a NiCoB-P-F high-efficiency hydrogen evolution electrocatalyst, its preparation method, and its application. The catalyst uses a monomeric NiCoB substrate, on which phosphorus (P) and phosphorus (F) elements are co-doped. The mass ratio of P to F is (2-6):(1-3). The raw material for P doping is NaH₂PO₂; the raw material for F doping is NH₄F. The method employs a vapor deposition process to co-dope P and F elements onto the monomeric NiCoB substrate. The hydrogen evolution electrocatalyst of this invention enhances the electrocatalytic performance of the hydrogen evolution reaction under alkaline conditions, with an overpotential η... 10 As low as 25mV, η 300 With a voltage as low as 134mV, it can significantly reduce the hydrogen evolution overpotential under high current density, thereby improving the overall catalytic efficiency and stability.

The invention relates to an electrode and a preparation method and application thereof, and belongs to the field of water electrolysis industry. The preparation method of the electrode comprises the following steps: providing an electroplating base material; nickel is plated on the surface of the electroplating base material to form a nickel plating layer, and a pre-plated base material is obtained; the pre-plated base material is added into a first electroplating solution to be electroplated to form an alloy plating layer, the electrode is obtained, and the first electroplating solution comprises a NiSO4 solution with the concentration being 0.5 mol / L to 1 mol / L, a Na2MoO4 solution with the concentration being 0.01 mol / L to 0.05 mol / L and a CuSO4 solution with the concentration being 0.1 mol / L to 0.5 mol / L. Compared with nickel or common nickel alloy, the prepared electrode has the advantages that the hydrogen adsorption performance is reduced, the overpotential is effectively reduced, and the water electrolysis performance is close to that of precious metal.

This invention discloses a method for preparing a cathode catalyst and positive electrode sheet for a neutral zinc-air battery, relating to the field of zinc-air batteries. The catalyst material is M-N-C (M being a transition metal). Nitrogen is dissociated by discharge in a nitrogen atmosphere using a plasma ball mill. Metal particles detach from the metal spheres composed of M under high-speed impact and are directly loaded onto a highly dispersed carbon substrate through electric field adsorption. The resulting mixture is then subjected to high-temperature heat treatment in a tube furnace under inert gas protection to obtain the target M-N-C catalyst material. When used as the cathode catalyst layer of a neutral zinc-air battery, the M-N-C catalyst material provided by this invention can effectively improve the reaction efficiency of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), reduce the overpotential of the zinc-air battery, improve the cycle stability of the neutral zinc-air battery, and increase its cycle life.

The invention provides a nickel electrode with a multi-level structure and a preparation method thereof. The preparation method mainly comprises the following steps: preparing a bottom-layer concave-convex substrate structure by mixed acid dipping, and forming a middle layer and a catalyst layer structure by surface heterogeneous growth. According to the method, tight combination of the catalyst layer and the substrate is taken as a guide, the uneven nickel metal substrate is obtained through mixed acid etching aiming at the problem that the catalyst is prone to falling off, and a highly rough surface is provided for in-situ growth of a subsequent columnar middle layer. The nickel metal substrate and the nanoflower layer catalyst are connected through the middle layer, the binding force of the catalyst and the substrate is effectively increased, the catalyst is prevented from falling off, and industrial stable water electrolysis is achieved. The surface of the synthesized nickel electrode with the multi-level structure has excellent performance stability, the overpotential is only increased by 8 mV when the nickel electrode runs for 1000 hours under the current density of 500 mA cm <-2 >, and only 1.83 V is needed when the nickel electrode is in an electrolytic bath.

The application relates to a noble metal active site enriched nanoporous amorphous alloy electrode material and electrolytic water catalytic application thereof. x Nb y N z The amorphous alloy thin strip is a precursor (wherein M is one or more than one of 3d transition metal elements Ni, Fe or Co, and N is one or more than one of noble metal elements Pt, Ir or Os), M and Nb elements are selectively removed by dealloying to obtain a nanoporous amorphous alloy electrode material composed of a surface nanometer noble metal enrichment layer, a middle nanoporous amorphous transition layer and an internal amorphous matrix layer, the electrode material has good mechanical bending flexibility, can be bent by 180 degrees at will without breaking, and is easy to prepare a self-supporting electrode device. The nanometer noble metal enrichment layer on the surface of the electrode material presents a multi-level pore structure composed of submicron 0.3-0.5 mu m honeycomb-shaped channels and superfine sponge-like 20-50 nm nanometer through holes, provides rich active sites, and exhibits excellent electrocatalytic performance: the hydrogen evolution overpotential is 17-30 mV at a current density of 10 mA / cm 2 The Tafel slope is 24-43 mV / dec, and the stable operation time can be more than 1000 hours under the condition of a current density of 500 mA / cm 2 The electrode material can be applied to the field of new energy such as electrolytic water catalytic hydrogen production.

The present inventions relate to methods, systems, apparatuses, controllers, software, and composition of matter associated with electrochemical energy storage devices. The present inventions relate to one or more additives for batteries, e.g., silicon-based batteries. The additives are integrated in the electrode counter-electrode, and / or electrolyte. The additives are configured to enhance electrochemical kinetics, reduce overpotential, suppress parasitic reactions, stabilize passivation layers, suppress dendrite formation, improve capacity retention, enable fast charging, increase coulombic efficiency, enhance reversibility over extended cycling, or any combination thereof.

The application provides a SOC and SOH combined estimation method of a full vanadium liquid flow battery, and the method comprises the following steps: S1. constructing an equivalent circuit model, determining parameters of the equivalent circuit model as an activation polarization overpotential V act , a concentration polarization overpotential V con , a pump loss current I pump , an ohmic loss R ohm and an open circuit voltage V s ; S2. constructing a parameter calculation model based on multiple physical fields for calculating the parameters in the equivalent circuit model; S3. substituting material performance parameter values of the full vanadium liquid flow battery into the parameter calculation model to obtain a full vanadium liquid flow battery simulation model with the same or similar material performance; and S4. inputting specific size parameter values of a monitored full vanadium liquid flow battery into the parameter calculation model in step S3 to estimate the SOC and SOH of the monitored full vanadium liquid flow battery. The application improves the universality of the equivalent circuit model for various types of full vanadium liquid flow batteries, can estimate the SOC and SOH of the positive and negative half-cells respectively, and more comprehensively monitors the conditions in the actual operation process of the full vanadium liquid flow battery.

A battery information generation apparatus according to an embodiment of the present disclosure includes a profile acquisition unit configured to acquire a differential profile representing a corresponding relationship between a voltage and a differential capacity of the battery; and a control unit configured to determine a target C-rate corresponding to the differential profile and generate a corrected profile by correcting the differential profile based on an overpotential profile corresponding to the target C-rate.

The application discloses a bimetallic organic gel electrode material suitable for wide power fluctuation and a preparation method and application thereof. The preparation method of the bimetallic organic gel electrode material comprises the following steps: dissolving transition metal nickel salt and transition metal cobalt salt in ethanol to obtain a transition metal salt mixed solution; under the atmosphere of nitrogen or inert gas, the transition metal salt mixed solution is added dropwise into a terephthalic acid mixed solution at 70-90 DEG C, and solvent thermal reaction is continuously carried out at 70-90 DEG C to obtain a colloidal suspension; centrifugation is carried out to obtain a precipitate; washing and vacuum drying are carried out to obtain the bimetallic organic gel electrode material. The bimetallic organic gel electrode material has excellent electrocatalytic hydrogen evolution and oxygen evolution activity, has a lower overpotential in the HER process in an alkaline environment, the lowest overpotential is 28 mV, and still has good stability under different large current densities, and has good electrochemical activity and wide power stability.

The application discloses a lithium-oxygen battery with high rate performance and a preparation method thereof, and relates to the technical field of lithium-oxygen batteries. The application uses carbon-based nanocage loaded with metal ruthenium (Ru) as a positive electrode catalytic composite material, and adds soluble redox medium ferrous glycinate (Fe(gly)2) in an electrolyte; the high catalytic activity of Ru is used to reduce the overpotential during the charging and discharging reaction of the lithium-oxygen battery; the large specific surface area and hierarchical pore structure of the carbon-based nanocage are used to assist the dispersion and accommodation of the discharge product Li2O2 and the transportation of oxygen, lithium ions and other materials; the Fe(gly)2 is used to effectively catalyze the formation of uniformly dispersed small-size particles of the Li2O2 discharge product and the performance of the decomposition during the charging process; in addition, the application limits the loading amount of the metal ruthenium on the positive electrode catalytic material to be 12-14 wt%, and the concentration of the Fe(gly)2 in the electrolyte to be 30-50 mM, so that the two fully play a synergistic role; under the conditions of a cutoff capacity of 1000 mAh / g and a current density of 5 A / g, the lithium-oxygen battery can be cycled for more than 150 cycles, and the rate performance and the cycle stability are obviously enhanced.

This invention belongs to the field of metal-organic gel materials technology, and discloses a metal-organic gel material for the interface layer of lithium metal battery anodes and its preparation method. The material uses a cerium-based metal-organic gel as its core, is prepared through a heating reaction, and an artificial interface layer is constructed on the surface of the lithium metal anode using a spin-coating method. This gel material possesses abundant metal open sites and a three-dimensional network microstructure, effectively adsorbing anions and solvent molecules, promoting lithium-ion dissociation and desolvation, while simultaneously accommodating deposited lithium metal. Symmetrical batteries based on this interface layer exhibit excellent cycle stability, operating stably for over 1000 hours with an overpotential below 20 mV, and effectively suppressing lithium dendrite growth. This invention provides a reliable material basis and technical solution for constructing high-energy-density, high-safety lithium metal batteries.

The invention relates to the technical field of new energy materials, in particular to a sodium ion host material, a preparation method thereof and a sodium metal battery. The material comprises a porous carbon base material, and nitrogen and phosphorus are doped in at least a surface layer region. On one hand, the rich open pore system of the porous carbon base material provides a containing space for sodium ion deposition, and the volume change is relieved; on the other hand, under the synergistic effect of the doped elements, the electronic structure and surface chemical properties of carbon atoms on the surface of the porous carbon are adjusted, the binding energy with sodium ions is improved, the sodium thinning phenomenon is improved, the nucleation overpotential of the sodium ions is reduced, then sodium dendrite growth is reduced, the polarization phenomenon is reduced, and the rate capability is improved; the surface layer area doped with the nitrogen element and the phosphorus element provides abundant active sites, sodium ions are induced to be uniformly deposited, and generation of sodium dendrites is further reduced. In conclusion, the sodium ion host material can relieve the problems of volume change, dendritic crystal growth, high nucleation overpotential and serious coulombic efficiency attenuation.

The invention discloses a current collector with an anti-dendritic carbon coating, a preparation method of the current collector, a pole piece and a sodium ion battery. The current collector comprises a copper foil substrate and a gradient carbon coating on the surface of the copper foil substrate, the carbon coating comprises a first carbon coating close to the copper foil substrate and a second carbon coating far away from the copper foil substrate. According to the gradient carbon coating scheme, the double-layer structure design is adopted, and the performance of the current collector of the sodium-ion battery is remarkably improved. The first carbon layer is mainly composed of graphene and carbon nanotubes, a low-porosity conductive layer is formed, uniform conduction of electrons is ensured, and dendritic crystal growth is avoided. The second carbon layer is mainly made of hard carbon and added with Sn or Bi nano-particles, a high-porosity sodium-philic layer is formed, the sodium deposition / removal overpotential is reduced, and the ion transmission path is optimized. According to the scheme, through material and process optimization, dendritic crystals can be effectively inhibited, the chemical stability is improved, the method has more advantages in cycling stability and safety, and a guarantee is provided for long-term reliability of the sodium-ion battery.

The invention provides a modified electrolyte of a rechargeable magnesium battery as well as a preparation method and application of the modified electrolyte. The modified electrolyte comprises a phenoxy magnesium-aluminum halide complex, an organic ether solvent and a lithium salt additive, the lithium salt additive is selected from at least one of lithium fluorosulfonate, lithium trifluoromethanesulfonate, lithium bis (fluorosulfonyl) imide and lithium bis (trifluoromethanesulfonyl) imide. The lithium salt additive does not contain chloride ions, corrosion to a current collector is inhibited, and a solvation structure of magnesium ions in the electrolyte is effectively regulated and controlled, so that the lithium salt additive has a wide electrochemical window, high ionic conductivity, low overpotential and high reversibility. The invention further provides a preparation method of the magnesium battery electrolyte, the preparation process is simple, convenient and efficient, raw materials are low in price, and industrial large-scale production is facilitated.