29 results about "Decomposition potential" patented technology

The invention belongs to the field of lithium ion batteries, and discloses a ZIF-67-derived composite lithium oxalate lithium supplement agent and a preparation method and application thereof.The lithium supplement agent comprises a lithium oxalate matrix and a ZIF-67-derived Co-based catalyst, and the ZIF-67-derived Co-based catalyst is evenly distributed on the surfaces of lithium oxalate particles or among crystals to form a composite structure; a water-phase synthesis method is adopted for preparation, ZIF-67 is converted into Co-based nano-particles, the Co-based nano-particles and lithium oxalate particles form a composite structure, the Co-based nano-particles can serve as a positive electrode additive to be applied to a positive electrode of a lithium ion battery, in-situ thermal decomposition / electrolytic reaction occurs in the first charging process of the battery, Li is released to compensate irreversible capacity loss, the decomposition potential can be reduced to 4.0 V or below, and the positive electrode additive can be applied to the positive electrode of the lithium ion battery. The first-time charging efficiency is improved to 90% or above, and the cycling stability is remarkably enhanced.

The invention belongs to the field of sodium-ion batteries, and discloses a sodium-ion battery electrolyte and a sodium-ion battery. The sodium-ion battery electrolyte comprises sodium salt, an organic solvent and an organic molecular additive shown in the following formula, wherein R1 to R5 are respectively and independently any one of F, Cl, Br, I, CN, H, OH, SH and NO2. A boron atom in the molecular structure of the additive is used as an electron-deficient center and can be preferentially complexed with anions or solvent molecules in the electrolyte to pre-stabilize an electrode interface; the bond energy of the B-O bond is moderate, so that the oxidation potential of the B-O bond is lower than that of a main body carbonate solvent, the B-O bond can be preferentially decomposed in the first charge-discharge process, and a thin, compact and highly stable positive electrode electrolyte interface film is formed on the surface of a positive electrode; the controllable substituent group on the benzene ring further regulates the decomposition potential of molecules through an electronic effect, so that the film forming time and the film property can be precisely regulated and controlled. The stable CEI can effectively inhibit continuous decomposition of the electrolyte at high temperature and high pressure, and the cycling stability of the battery in the high-temperature and high-pressure environment is remarkably improved.

This application provides a secondary battery and an electrical device, relating to the field of lithium battery technology. On one hand, this application utilizes a second positive electrode active material for positive electrode lithium replenishment to improve the cycle performance of the secondary battery. On the other hand, because the carbon layer on the surface of the second positive electrode active material has a certain catalytic effect on phosphate ester film-forming additives, it can reduce the decomposition potential of phosphate ester film-forming additives on the surface of the second positive electrode active material. This results in some phosphate ester film-forming additives preferentially forming a CEI film on the surface of the second positive electrode active material at a lower voltage, effectively suppressing the active sites of the carbon layer and inhibiting side reactions between the second positive electrode active material and the solvent at lower voltages. The remaining phosphate ester film-forming additives preferentially form a CEI film on the surface of the first positive electrode active material before solvent decomposition during formation, isolating the solvent from contact with the first positive electrode active material, suppressing side reactions, and improving cycle performance.

This invention belongs to the technical field of sodium-ion battery electrode materials, specifically relating to a preparation method and application of an air-stable molten asphalt-coated sodium selenide composite cathode sodium replenisher. The invention first prepares pure-phase sodium selenide nanoparticles in a glove box by room temperature stirring. Then, asphalt is grown in situ on the surface of the sodium selenide through ball milling and high-temperature calcination, thereby forming a core-shell structured sodium selenide composite sodium replenisher material coated with molten asphalt. The resulting composite sodium replenisher is stable in air for extended periods without deterioration, while simultaneously reducing the decomposition potential of sodium selenide and improving its decomposition efficiency. Coupled with a layered oxide cathode, it can achieve cathode sodium replenishment, compensating for the loss of active sodium caused by the growth of the SEI film on the surface of the hard carbon anode. Furthermore, its decomposition product, selenium, can inhibit the lattice oxygen evolution of the layered oxide cathode, improving the structural stability of the cathode and thus effectively enhancing the battery's initial efficiency and cycle performance, demonstrating promising commercial application prospects.

The invention provides an organic lithium salt and a preparation method and application thereof, the organic lithium salt has a structure as shown in a formula I. Through the design of a molecular structure, the organic lithium salt has high capacity and excellent stability, does not generate adverse side reaction in air, solvent and other environments, and is low in decomposition potential and high in stability. The lithium supplement agent can be compatible with various battery systems and manufacturing processes, products obtained after decomposition / lithium removal can enter electrolyte, the positive effect on the cycle performance of the battery is achieved, and the lithium supplement agent is excellent in comprehensive performance. The organic lithium salt is used in a lithium ion battery, is especially suitable for being used as a positive electrode lithium supplement agent to prepare a positive electrode plate, and can significantly improve the capacity and cycle performance of the battery.

The present application relates to a kind of decomposable organic lithium salt for positive electrode lithium supplement agent and its preparation method.Compared with the currently commercialized positive electrode lithium supplement additive, the decomposable organic lithium salt of the present application has the advantages of high theoretical capacity, high air stability, simple preparation process, etc.The lithium salt is prepared by the reaction of a specific precursor and lithium source, and the theoretical capacity and decomposition potential of the lithium salt can be changed by changing the R group of the precursor, and an organic decomposable lithium salt lithium supplement agent is prepared by mixing with conductive carbon.The lithium supplement agent can be added to the positive electrode slurry during battery manufacturing process, and is compatible with the current battery manufacturing process.The lithium salt anion decomposes during charging and does not remain in the positive electrode, ensuring the energy density of the battery.The small molecules generated by decomposition form a solid electrolyte membrane (SEI) rich in inorganic components with the negative electrode, enhancing the mechanical strength of the SEI and prolonging the service life of the battery.

The application relates to the technical field of lithium battery diaphragm, in particular to a modified PE diaphragm with low decomposition voltage and high lithium supplement capacity and a preparation method thereof. The preparation method comprises the following steps: mixing C3N4, a molybdenum source, a cobalt source and citric acid to obtain a precursor; sintering the precursor under a protective atmosphere to obtain a composite catalyst; mixing the composite catalyst, a conductive agent, a binder, lithium oxalate and a solvent to obtain a slurry; and coating the slurry on the surface of a PE diaphragm to obtain the modified PE diaphragm with low decomposition voltage and high lithium supplement capacity after drying. The composite catalyst is obtained by sintering a multiphase precursor, the slurry is mixed with a conductive agent, a binder, lithium oxalate and the like, and is coated on the PE diaphragm, so that the decomposition potential of lithium oxalate can be greatly reduced, the problem that lithium oxalate is difficult to supplement lithium efficiently in a ternary positive electrode system can be effectively solved, the specific capacity of lithium oxalate released at low voltage can be improved, and the effect of high lithium supplement capacity is achieved.

An electrolyte (105), a lithium-ion battery (100), an electric device, and an energy storage system. The electrolyte (105) is suitable for a lithium-ion battery (100) comprising a lithium supplementing agent; the electrolyte (105) comprises an organic additive; the organic additive can be dissolved in the electrolyte (105); the oxidation-reduction potential of the organic additive is greater than the decomposition potential of the lithium supplementing agent. The organic additive can promote decomposition of the lithium supplementing agent and effectively reduce the decomposition potential of the lithium supplementing agent, thereby achieving the purpose of compensating for lithium loss of the lithium-ion battery. Moreover, the organic additive is easily dissolved in the electrolyte (105), diffuses to the surface of the lithium supplementing agent along with the electrolyte (105), and is in full contact with the lithium supplementing agent, thereby fully reducing the decomposition potential of the lithium supplementing agent, and increasing the utilization rate of the lithium supplementing agent.

The invention discloses a modified lithium supplement agent and a preparation method and application thereof, and belongs to the field of lithium ion battery positive electrode materials. The lithium supplement agent is of a porous net structure and comprises lithium oxalate, conductive carbon and an additive, the additive takes carbon as a substrate, and Mn-Mo bimetal ions are loaded on the substrate. The mass ratio of the metal Mn to the metal Mo is (1-3): 1. The mass ratio of the additive to the conductive carbon is (0.5-5): 1. The preparation method of the modified lithium supplement agent comprises the following steps: (1) placing a carbon material in strong acid, and carrying out modification treatment to obtain a modified carbon material; (2) impregnating the modified carbon material with manganese salt and molybdenum salt, and sintering to obtain an additive with manganese and molybdenum loaded on the carbon material; and (3) adding conductive carbon and an additive into the lithium oxalate solution, spraying, and drying to obtain the modified lithium supplement agent. According to the modified lithium supplement agent prepared by the method, the lithium oxalate decomposition potential is remarkably reduced, and the overall electrochemical performance is excellent.

The invention belongs to the technical field of sodium ion batteries, and particularly relates to an efficient sodium formate composite positive electrode sodium supplementing agent and preparation and application thereof. According to the preparation method, firstly, iron cluster catalyst particles are prepared through high-temperature calcination, then sodium formate grows on the surface of the catalyst in situ through an anti-solvent crystallization method, the composite sodium supplementing material is formed, and the composite structure can synchronously achieve reduction of the decomposition potential of sodium formate and improvement of the decomposition efficiency. Meanwhile, after the composite sodium-supplementing material is coupled with a layered oxide positive electrode, an efficient positive electrode sodium-supplementing effect can be played, active sodium loss caused by formation of a hard carbon negative electrode SEI film is made up, the first effect and the cycle performance of the battery are improved, and nearly 100% decomposition efficiency can be achieved. The molecular catalytic coupling size control effect is originally created, the sodium supplementing performance of sodium formate is remarkably improved, after the sodium formate is applied to a layered oxide positive electrode hard carbon negative electrode battery system, the first effect and the cycle performance of a battery are effectively improved, and good commercial application prospects are achieved.

The invention discloses a secondary battery, a capacity compensation agent, a preparation method of the capacity compensation agent and electric equipment, the secondary battery comprises a positive pole piece, a negative pole piece and an isolating membrane, the positive pole piece comprises a positive current collector and a positive membrane layer located on at least one side of the positive current collector, the positive membrane layer comprises the capacity compensation agent, and the capacity compensation agent is located on at least one side of the negative current collector. The capacity compensation agent comprises a compound shown as a formula 1: R-COOM formula 1, R comprises an electron donating group, and M comprises one or two of Na or Li; the volume average particle size Dv50 of the volume compensating agent meets the condition that Dv50 is less than or equal to 4 microns. Therefore, the decomposition potential of the capacity compensation agent is reduced, and the capacity compensation effect is improved.

The application discloses a positive electrode sheet and a preparation method therefor, and a battery and an electric device. The positive electrode sheet comprises a positive active material layer; and a capacity compensation layer arranged on one side of the positive active material layer, wherein the capacity compensation layer comprises a catalyst and a capacity compensation agent, the average particle size of the capacity compensation agent is less than or equal to 2 mu m, and the average particle size of the catalyst is less than or equal to the average particle size of the capacity compensation agent. In this way, the probability of contact between the catalyst and the capacity compensation agent is improved, the decomposition potential of the capacity compensation agent is reduced, and the capacity retention rate and the service life of the battery are improved.

The application belongs to the technical field of energy storage batteries, and discloses a composite nano organic lithium supplementing agent, a preparation method thereof and a positive electrode sheet. The composite nano organic lithium supplementing agent is composed of an active lithium source, a catalyst, a conductive network material and various auxiliary additives, and through precise control of the proportion of each component and the preparation process, the supplementing performance of lithium is optimized. The preparation of the active lithium source at a specific pH value can control the nucleation and growth process kinetics of the active lithium source, and at the pH value, the spray drying process can ensure the precipitation of spherical nanoparticles, and can provide sufficient recyclable lithium. The catalyst uses the ligand-metal charge transfer principle to reduce the oxidation decomposition potential of the unsaturated C=O bond in the carboxylate of the active lithium source. The conductive network material constructs an efficient electron transport path, and the dispersibility, stability and mechanical properties of the lithium supplementing agent are optimized through auxiliary additives. The composite nano organic lithium supplementing agent has excellent mechanical properties, good decomposition kinetics and good conductive performance, and can fully supplement lithium. After being applied to a lithium ion battery, the composite nano organic lithium supplementing agent can significantly improve the initial coulomb efficiency, energy density and cycle stability of the battery, and is suitable for new system batteries such as high-voltage positive electrode materials and silicon-based negative electrodes.

The application belongs to the field of lithium ion batteries, and discloses a ZIF-67 derived lithium oxalate lithium supplementing agent, a preparation method and application thereof. The lithium supplementing agent comprises a lithium oxalate matrix and a ZIF-67 derived Co-based catalyst. The ZIF-67 derived Co-based catalyst is uniformly distributed on the surface or intercrystalline of the lithium oxalate particles to form a composite structure. The preparation adopts an aqueous phase synthesis method to convert the ZIF-67 into Co-based nanoparticles and form a composite structure with the lithium oxalate particles. The lithium supplementing agent can be applied to a lithium ion battery positive electrode as a positive electrode additive. In the first charging process of the battery, in-situ thermal decomposition / electrolysis reaction occurs to release Li+ to compensate for irreversible capacity loss. The decomposition potential can be reduced to below 4.0 V, the first charging efficiency is increased to above 90%, and the cycle stability is significantly enhanced.

The invention discloses a boron-based electrolyte for a rechargeable magnesium battery and application of the boron-based electrolyte. The electrolyte consists of a solvent and a solute, the solvent is organic ether; the solute is composed of organic boric acid ester and alkyl magnesium halide; wherein the concentration of the alkyl magnesium halide in the electrolyte is 0.1 mol / L-2mol / L, and the molar ratio of the organic boric acid ester to the alkyl magnesium halide is 1: (1-3). The electrolyte is applied to the rechargeable magnesium battery, the anodic oxidation decomposition potential can reach 3.5 V vs.Mg or above, and the efficiency is kept 99% or above in the stable cycle process; the electrolyte has the advantages of being simple to prepare, low in raw material cost, high in magnesium deposition-dissolution efficiency and high in anodic oxidation decomposition potential.

The invention provides recrystallized lithium oxalate and a preparation method thereof, a positive plate, a secondary battery and an electric device. The preparation method comprises the following steps: S1, mixing lithium oxalate with water to obtain a lithium oxalate supersaturated solution; step S2, recrystallizing the lithium oxalate supersaturated solution to obtain recrystallized lithium oxalate; wherein the mass concentration of the lithium oxalate supersaturated solution is 1.1-1.3 times of the mass concentration of the lithium oxalate saturated solution. Recrystallized lithium oxalate with smaller granularity is formed through a recrystallization technology, so that the reduction of surface electron and lithium ion transmission paths of recrystallized lithium oxalate is facilitated, the oxygenolysis of recrystallized lithium oxalate is facilitated, the decomposition potential of recrystallized lithium oxalate is effectively reduced, and the lithium supplement effect of recrystallized lithium oxalate is improved; therefore, the capacity and the cycling stability of the secondary battery can be improved.

The invention relates to the technical field of lithium battery diaphragms, in particular to a modified PE diaphragm with low decomposition voltage and high lithium supplement capacity and a preparation method of the modified PE diaphragm. The preparation method comprises the following steps: mixing C3N4, a molybdenum source, a cobalt source and citric acid to obtain a precursor; sintering the precursor in a protective atmosphere to obtain a composite catalyst; mixing the composite catalyst, a conductive agent, a binder, lithium oxalate and a solvent to obtain slurry; and coating the surface of a PE diaphragm with the slurry, and drying to obtain the modified PE diaphragm with low decomposition voltage and high lithium supplement capacity. The composite catalyst, the mixed conductive agent, the binder, the lithium oxalate and other homogenates are obtained by sintering the multi-phase precursor and are coated on the PE diaphragm, so that the decomposition potential of the lithium oxalate can be greatly reduced, the problem that the lithium oxalate in a ternary positive electrode system is difficult to efficiently supplement lithium is effectively solved, the specific capacity released by the lithium oxalate under low voltage is improved, and the service life of the ternary positive electrode system is prolonged. And the effect of high lithium supplement capacity is achieved.

The application provides a positive electrode lithium supplementing pole piece slurry, a preparation method of a pole piece and a battery formation method, and belongs to the technical field of lithium ion batteries. The application comprises the following steps: preparing a lithium oxalate dispersion liquid; mixing lithium iron phosphate powder and a conductive agent, and then adding the lithium oxalate dispersion liquid and a binder to prepare a slurry; the particle size of lithium oxalate in the lithium oxalate dispersion liquid and the lithium iron phosphate powder satisfies the following formula: D 50LFP :D 50LCO =100:(15-25), the D 50LFP range is 1.0-2.0 um, wherein D 50LFP is the D 50 particle size of lithium iron phosphate, and D 50LCO is the D 50 particle size of lithium oxalate. Based on the theoretical decomposition potential of lithium oxalate, a plurality of nano-micron scale corrosion battery models are constructed in the positive electrode pole piece, the chemical properties of phosphoric acid iron after lithium is removed from lithium iron phosphate are utilized, lithium oxalate is electrochemically / chemically catalytically decomposed, and the decomposition potential of lithium oxalate is reduced to 3.5 V.

The invention belongs to the field of lithium batteries, and relates to a lithium cobalt oxide ether gel electrolyte applied to high voltage and a preparation method thereof, and the ether gel electrolyte comprises the following components in percentage by mass: 3-30% of a cross-linking agent monomer material, an initiator, 10-20% of a lithium salt, 60-85% of an organic solvent and 0.1-10% of an additive. The lithium salt is one or more of LiPF6, LiTFSI, LiDFOB, LiFSI and the like; the organic solvent is composed of one or more of an ether solvent, an ester solvent, a fluorinated solvent and the like; the additive is formed by mixing lithium ion salts or esters in any proportion. The ether electrolyte provided by the invention is helpful for forming stable CEI / SEI films on the surfaces of a high-voltage positive electrode material and a negative electrode material, and has relatively high electrochemical window and oxygenolysis potential gt; and meanwhile, when the material is applied to a high-voltage lithium cobalt oxide battery, the material shows good cycle stability.

A lithium replenishment material and its preparation method, a positive electrode sheet, and a secondary battery are disclosed. The lithium replenishment material includes a core; the core includes a lithium-rich compound doped with element A, which is a metallic element; the core also includes ion vacancies formed by element A replacing the metallic element in the lithium-rich compound; ion vacancies are formed by doping element A into the core of the lithium replenishment material; oxygen generated during charging is adsorbed by the ion vacancies, and the oxygen is converted into lattice oxygen during discharging, thus suppressing the generation of gas in the secondary battery during operation; at the same time, the doped element A can also regulate the electronic structure in the lithium replenishment material, improve its electronic conductivity, reduce the decomposition potential and interface resistance of the lithium replenishment material, thereby improving the lithium-ion transport rate.

The invention discloses a hydrogen peroxide continuous purification method and device with an anti-decomposition safety interlock, and belongs to the technical field of purification of inorganic compounds, and the method comprises the following steps: dynamically adjusting a pressure fine adjustment unit based on multi-point pressure and temperature parameters in a rectifying tower to establish a non-uniform pressure field, and carrying out continuous vacuum rectification; the tower top steam and a stabilizer precursor react in an in-situ capture reactor containing a catalyst to generate an in-situ stabilizer, and self-inhibition reflux is formed and returned to the rectifying tower; system state parameters are monitored in real time, decomposition potential energy indexes are calculated, and pressure adjusting logic or stabilizer precursor injection parameters are actively optimized based on the change trend of the decomposition potential energy indexes. The decomposition potential energy index is calculated in real time by adopting the digital twin model, the pressure field and stabilizer injection parameters are dynamically adjusted in combination with an active optimization instruction based on the index change trend, and the whole-process decomposition inhibition and safety interlocking control of the hydrogen peroxide purification process can be realized.

The invention discloses an ion battery and electric equipment comprising the same, the ion battery comprises a positive pole piece, the positive pole piece comprises a positive current collector, at least one side of the positive current collector is provided with a positive film layer, the positive film layer comprises a capacity compensation agent, and the capacity compensation agent comprises a compound shown as a formula I: Mf1Pf2CbOcHdNe, m comprises Li element or Na element, 1 < = f1 + f2 < = 5, 0 < = b < = 14, 1 < = c < = 5, 0 < = d < = 19, 0 < = e < = 3, P comprises a metal element, the ion radius of the metal element is greater than the ion radius of the M element, and 0 < f2 < 1. Therefore, by doping the metal elements with the content in the capacity compensation agent, the structural stability of the capacity compensation agent can be reduced, the decomposition potential of the capacity compensation agent can be reduced, the first-circle discharge gram capacity of the positive electrode active material can be improved, and the cycle capacity retention ratio of the battery can be improved.

The application discloses a hydrogen peroxide continuous purification method and device with anti-decomposition safety interlocking, and belongs to the technical field of inorganic compound purification, which comprises the following steps: establishing a non-uniform pressure field by adjusting the pressure fine tuning unit based on the multi-point pressure and temperature parameters in the rectifying tower to perform continuous vacuum rectification; reacting the tower top steam and the stabilizer precursor in an in-situ capture reactor containing a catalyst to generate an in-situ stabilizer, and returning the self-inhibition reflux liquid to the rectifying tower; monitoring the system state parameters in real time and calculating a decomposition potential energy index, and actively optimizing the pressure adjustment logic or the stabilizer precursor injection parameters based on the change trend thereof. The application adopts a digital twin model to calculate the decomposition potential energy index in real time, combines the active optimization instruction based on the change trend of the index, dynamically adjusts the pressure field and the stabilizer injection parameters, and can realize the whole-process decomposition inhibition and safety interlocking control of the hydrogen peroxide purification process.

The application belongs to the technical field of sodium ion batteries, and relates to a sodium supplementing additive, a positive electrode sheet and a sodium ion battery. In order to solve the problem of excessively high decomposition potential of the existing positive electrode sodium supplementing additive, sodium chromate and an organic sodium supplementing agent (such as sodium formate) are treated through a molten salt compounding process (calcination under inert atmosphere after tabletting) to prepare the sodium supplementing additive. The molten salt compounding process improves the interface contact and compounding uniformity of the inorganic additive and the organic sodium supplementing agent, so that, in the first charging process, the high-valence Cr 4+ generated by the decomposition of sodium chromate can efficiently catalyze the decomposition of the organic sodium supplementing agent, thereby significantly reducing the decomposition potential. The compounding sodium supplementing agent of the application is compatible with the existing electrode process, and can effectively improve the initial coulomb efficiency and the full battery energy density of the sodium ion battery. The compounding sodium supplementing additive prepared by the application can be directly added to the positive electrode slurry, is compatible with the existing electrode process, and has good industrial application prospect.

The invention discloses a sodium secondary battery monomer and a preparation method thereof, a sodium supplementing agent and a preparation method thereof and electric equipment, the sodium secondary battery monomer comprises a positive pole piece, the positive pole piece comprises a positive pole current collector and a positive pole film layer located on at least one side of the positive pole current collector, the positive pole film layer comprises the sodium supplementing agent, and the negative pole piece comprises a negative pole current collector and a negative pole film layer located on at least one side of the negative pole current collector. The sodium supplementing agent comprises a matrix, at least part of the surface of the matrix is provided with a coating layer, and the coating layer comprises an oxygen-containing polymer; the negative electrode plate comprises a negative electrode current collector; and the isolating membrane is arranged between the positive pole piece and the negative pole piece. Therefore, before the battery voltage in the formation stage reaches the decomposition potential of the sodium supplementing agent, the stability of the sodium supplementing agent is improved; and after the battery voltage reaches the decomposition potential of the sodium supplementing agent, the sodium supplementing agent is decomposed to release sodium ions so as to compensate the sodium ions consumed by forming the SEI membrane, and further the cycle performance of the sodium secondary battery monomer is improved.

The application discloses a modified lithium carbonate positive electrode lithium supplement and application thereof, and the component of the lithium carbonate positive electrode lithium supplement is a Li2CO3 / transition metal oxide heterojunction composite material, wherein the transition metal includes one or more of Co, Fe, Ni and Mn. Specifically, after lithium carbonate is dissolved, a transition metal salt source is added, and a Li2CO3 / transition metal oxide heterojunction is generated through anti-solvent precipitation and heat treatment. The positive electrode lithium supplement significantly reduces the decomposition potential of Li2CO3, and when applied to a positive electrode material, the decomposition potential can be further reduced, and is highly matched with an existing positive electrode working window. The decomposition efficiency of the positive electrode lithium supplement is high, and the irreversible lithium loss in the first charge-discharge process of a lithium ion battery can be effectively compensated. The positive electrode and the lithium ion battery containing the positive electrode lithium supplement have higher first coulomb efficiency, energy density and excellent cycle stability. The application realizes efficient decomposition of Li2CO3 under extremely low catalyst consumption, solves the problem of too high proportion of non-active components, and has extremely high industrial application value.

The invention provides ionic liquid for a battery negative electrode, an electrode plate and a battery, and relates to the technical field of batteries. The ionic liquid contains organic cations and anions; the organic cation comprises an alkenyl functional group which can be electrochemically polymerized; the anion is a bis (fluorosulfonyl) imide radical or a bis (trifluoromethanesulfonyl) imide radical; wherein the alkenyl functional group is used for polymerizing to form a flexible polymer network under the negative electrode potential when the battery is charged for the first time, and the reduction decomposition potential of the anions is higher than that of the carbonic ester electrolyte solvent, and is used for preferential reduction decomposition after polymerization; and a composite SEI film with gradient change of components and modulus is constructed in situ on the surface of the negative electrode in cooperation with a polymer network. The membrane not only can effectively inhibit the volume change damage and dendritic crystal growth of an active negative electrode, but also obviously optimizes the interface compatibility and ion transport kinetics between the negative electrode and a solid electrolyte, thereby comprehensively improving the cycle life, the capacity retention ratio and the rate capability of the battery.

The invention relates to an electrode material additive and a preparation method and application thereof, and the preparation method of the electrode material additive comprises the following steps: adding soluble organic transition metal salt and soluble sodium salt into a solvent, uniformly mixing, and drying to obtain mixed powder; placing the mixed powder in an inert atmosphere or a weak reducing atmosphere, heating to 300-500 DEG C for sintering, cooling to room temperature, and then performing high-energy ball milling for reaction to obtain the electrode material additive, according to the invention, the organic transition metal salt and the soluble sodium salt are mixed, the mixture is heated at a specific temperature for reaction, and then high-energy ball milling is continuously used for reaction, so that the transition metal can be efficiently doped in crystal lattices of the sodium salt and forms stable chemical bonds with the sodium salt, thereby obviously reducing the overall decomposition potential and increasing the actual capacity.

The invention belongs to the technical field of sodium ion batteries, relates to a sodium supplement additive, a positive pole piece and a sodium ion battery, and aims to solve the problem that the decomposition potential of the existing positive pole sodium supplement additive is too high. Sodium chromate and an organic sodium supplement agent (such as sodium formate) are treated through a molten salt composite process (calcining in an inert atmosphere after tabletting); and preparing to obtain the sodium supplementing additive. The interface contact and compounding uniformity of the inorganic additive and the organic sodium supplementing agent is improved through a molten salt compounding process, so that high-valence Cr < 4 + > generated by sodium chromate decomposition can efficiently catalyze decomposition of the organic sodium supplementing agent in the first-circle charging process, and the decomposition potential of the organic sodium supplementing agent is remarkably reduced. The composite sodium supplementing agent can be compatible with an existing electrode process, and the first coulombic efficiency and the total battery energy density of the sodium ion battery are effectively improved. The prepared composite sodium supplement additive can be directly added into positive electrode slurry, is compatible with an existing electrode process, and has a good industrial application prospect.