11results about How to "Increase sodium storage capacity" patented technology

The application relates to the technical field of sodium ion battery positive electrode materials, in particular to a Na2Fe2(SO4)3@Na3Fe2(SO4)3F@CNT positive electrode material.The Na2Fe2(SO4)3 and Na3Fe2(SO4)3F precursors are mixed and sintered, and are coated by CNT, so that the electrochemical performance of the Na2Fe2(SO4)3 is remarkably improved, the conductivity of the material is improved, the material can be used as a sodium ion battery positive electrode material, has a high discharge specific capacity, and has cycle performance and rate performance.

The application provides a sodium ion battery negative electrode material and a preparation method thereof. The preparation method of the sodium ion battery negative electrode material comprises the following steps: obtaining a coal-based raw material; performing a defect operation on the coal-based raw material, so that the coal-based raw material is oxidized and crosslinked to obtain a pre-oxidized coal-based negative electrode material; performing a hot extraction treatment on the pre-oxidized coal-based negative electrode material to remove organic impurities in the pre-oxidized coal-based negative electrode material; and performing a high-temperature doping operation on the pre-oxidized coal-based negative electrode material after the hot extraction treatment to obtain the sodium ion battery negative electrode material. The preparation method of the sodium ion battery negative electrode material can effectively change the disorder degree of the microstructure, increase the interlayer spacing of the coal-based raw material, and further effectively improve the reversible specific capacity and the cycle performance.

The application belongs to the technical field of battery materials, and particularly relates to a Prussian blue-like nano positive electrode material, a preparation method thereof and a sodium ion battery. x M y [Fe(CN)6] z , wherein M is a transition metal element, and 0

The invention discloses a bamboo-based derived nitrogen-doped hard carbon negative electrode material and a preparation method and application thereof.The preparation method creatively utilizes the characteristic that bamboo wood is rich in natural phenolic hydroxyl groups and comprises the steps that bamboo powder and an aldehyde group compound are subjected to in-situ phenol-aldehyde polycondensation under the alkaline condition, and a cross-linked network precursor is constructed; then adjusting the pH to weak acidity, and carrying out in-situ amination doping with a nitrogen-containing compound; and finally, carbonizing to obtain the nitrogen-doped hard carbon material. According to the method, structural reconstruction and uniform nitrogen doping of the bamboo-based precursor are synchronously realized through two-step continuous molecular-level reaction of'alkaline polycondensation-acidic amination '. When the obtained material is used as a sodium ion battery negative electrode, high reversible specific capacity (greater than 304 mAh / g), high first coulombic efficiency (greater than 92%) and excellent cycling stability (300-week capacity retention rate at 0.5 C is greater than 92%) are shown. The method is simple in process, green, low in cost and suitable for large-scale production.

The invention relates to the technical field of electrochemical materials, in particular to a pre-sodium hard carbon material and a preparation method and application thereof. The pre-sodium modification method for preparing the pre-sodium modification hard carbon material comprises the following steps: (1) mixing a carbon source, amino acid and phosphoric acid, and carrying out pre-carbonization reaction to obtain a doped carbon source; (2) providing dispersion liquid containing the doped carbon source, a surfactant and weak base, and introducing organic sodium salt to carry out sodium pre-modification reaction to obtain a hard carbon precursor; and (3) carrying out carbonization reaction on the hard carbon precursor to obtain the pre-sodium hard carbon material. The pre-sodium treatment method is simple to operate and high in safety, the obtained pre-sodium treatment hard carbon material is excellent in performance, and the problems that a sodium ion battery is low in energy density and poor in cycle performance can be effectively solved.

The application discloses a preparation method of a closed micropore structure sodium ion battery negative electrode hard carbon material, and comprises the following steps: S1, preparation of a precursor mixed solution: biomass raw material powder and an inorganic acid pore former are used to prepare the precursor mixed solution; S2, carbon precursor drying: the precursor mixed solution is dried to prepare the carbon precursor; S3, pore forming of a closed pore carbon intermediate: the carbon precursor is subjected to high-temperature activation reaction to obtain the closed pore carbon intermediate with a micropore structure after activation; S4, closed pore carbon intermediate refining treatment: the carbon intermediate is crushed and refined, and the refined closed pore carbon intermediate is obtained through sieving; and S5, high-temperature carbonization of the hard carbon material: the refined carbon intermediate obtained in the step S4 is subjected to high-temperature carbonization to obtain the hard carbon material with the closed micropore structure. The application has the characteristics of a green and environment-friendly process, a small specific surface area and excellent electrochemical performance.

The invention discloses a lignin polyaniline composite binder, preparation thereof and application of the lignin polyaniline composite binder in a hard carbon negative electrode of a sodium-ion battery. The method comprises the following steps: firstly, performing carboxymethylation modification on lignin to obtain carboxymethyl lignin; then, polyhydric alcohol serves as a cross-linking agent, a covalent bond is formed through dehydration condensation of hydroxyl on a molecular chain of the polyhydric alcohol and carboxyl of the carboxymethyl lignin, meanwhile, the polyhydric alcohol, the conductive polyaniline and the carboxyl of the carboxymethyl lignin are subjected to cross-linking compounding through the hydrogen-bond interaction between the hydroxyl of the polyhydric alcohol and amino on a molecular chain of the conductive polyaniline, and the lignin polyaniline composite binder is constructed. According to the composite binder, the compatibility of a hard carbon negative electrode and an ester or ether electrolyte is improved, and the structural integrity of the electrode and a stable SEI film can be effectively maintained in the circulation process, so that the first effect, the circulation stability and the rate capability are remarkably improved.

The application provides a preparation method of a hard carbon negative electrode material of a sisal for a sodium ion battery, and comprises the following steps: cutting the dried sisal into small pieces; putting a proper amount of the sisal into an acid-containing reaction kettle to perform a hydrothermal reaction, then washing to neutral, and drying to obtain a first black plant fiber; putting the black plant fiber of step S2 into an alkali-containing reaction kettle to perform a hydrothermal reaction, then washing to neutral, and drying to obtain a second black plant fiber; performing high-temperature carbonization of the second black plant fiber of step S3 in an inert gas atmosphere, then cooling to room temperature to obtain the hard carbon negative electrode material of the sisal; wherein the carbonization temperature is 1100-1500 DEG C, the holding time is 0.5-3h, and the heating / cooling rate is 1-10 DEG C / min. The preparation method of the hard carbon negative electrode material of the sisal for the sodium ion battery has high platform capacity and excellent long cycle stability.

The application belongs to the technical field of sodium ion negative electrode material preparation technology, and particularly relates to a double-layer carbon-coated sodium ion battery hard carbon negative electrode material and a preparation method and application thereof. The method comprises the following steps: dispersing active carbon powder in a trimethylol aminomethane hydrochloride buffer solution, then adding hydrochloric acid dopamine for self-polymerization reaction to obtain first-layer polydopamine-coated active carbon powder; then placing the active carbon powder in a second-layer carbon source precursor solution, water-bath heating to obtain double-layer carbon-coated active carbon powder; and finally performing heat treatment to obtain the double-layer carbon-coated hard carbon negative electrode material. The method of the application firstly coats the first-layer polydopamine on the surface of the active carbon through in-situ polymerization, then promotes uniform coating of the second-layer carbon source precursor by using the strong adhesion of the polydopamine, and obtains the double-layer carbon-coated hard carbon negative electrode material after heat treatment; the hard carbon negative electrode material can improve the energy density of the current sodium ion battery and accelerate the industrialization application of the sodium ion battery.

The invention provides a high-specific-capacity hard carbon material as well as a preparation method and application thereof. The high-specific-capacity hard carbon material is prepared from raw materials including a phenolic compound, an aldehyde compound, a catalyst and a curing agent, the preparation method comprises the following steps: (1) uniformly mixing a phenolic compound, an aldehyde compound and a catalyst in water, and reacting to obtain a low-molecular-weight resin solution; (2) adding an amine curing agent into the low-molecular-weight resin solution obtained in the step (1), uniformly mixing, and carrying out hydrothermal reaction to obtain high-molecular-weight cross-linked resin; and (3) carrying out low-temperature calcination on the high-molecular-weight cross-linked resin obtained in the step (2) in an oxygen-containing gas atmosphere, then carrying out high-temperature calcination in a protective gas atmosphere, and cooling to room temperature to obtain the high-specific-capacity hard carbon material. The prepared high-specific-capacity hard carbon material is high in reversible specific capacity, the first coulombic efficiency and the rate capability are kept at a high level, and the comprehensive sodium storage performance is excellent.

The application provides a sodium ion battery, an energy storage device, a power utilization system and an energy storage system. The sodium ion battery provided by the application comprises a negative electrode sheet, a positive electrode sheet and a sodium storage layer. The negative electrode sheet comprises a negative electrode current collector and a negative electrode material layer arranged on the surface of the negative electrode current collector. The negative electrode material layer comprises a sodium storage layer and a conductive framework layer. The sodium storage layer is closer to the negative electrode current collector than the conductive framework layer. The positive electrode sheet comprises a positive electrode current collector and a positive electrode material layer arranged on the surface of the positive electrode current collector. The ratio of the capacitance of the sodium storage layer to the capacitance of the positive electrode material layer is CB, and 0.8<=CB<=1.4. The sodium ion battery provided by the application has a high cycle capacity retention rate.