Novel modified siocn materials and their use in energy storage devices

Abstract

The application discloses a novel modified SiOCN material and application thereof in the field of energy storage devices. The SiOCN material is prepared by the following steps: reacting amino-containing organosiloxane with an organic aldehyde compound, a metal ion-containing organic aldehyde compound, an organic polyacid compound or a metal salt thereof, and a metal organic alkoxyl compound to prepare a metal-containing precursor, and then calcining the metal-containing precursor under the protection of an inert gas to obtain the modified SiOCN material. The preparation method of the novel modified SiOCN material is simple and green, and the composition content of the SiOCN material can be controlled; when the SiOCN material is used as a negative electrode material of a lithium ion battery, the reversible capacity of the material can be improved, and excellent rate performance and cycle stability are obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nano energy storage materials and devices, and particularly relates to a novel modified SiOCN material and application thereof in the field of energy storage devices. BACKGROUND

[0002] In the field of new energy, lithium ion batteries have the advantages of high working voltage, high energy density, long cycle life, small self-discharge, no memory effect, etc., and have been widely used in many fields, such as intelligent mobile devices, electric vehicles, and electric energy storage. However, there are still many deficiencies in the related technology of lithium ion batteries, such as the energy density, power density, thermal stability, and charging efficiency of the battery, which need to be further improved. The performance of lithium ion batteries mainly depends on the positive and negative electrode materials, and the development of negative electrode materials with higher energy density is one of the current research focuses. The theoretical lithium intercalation capacity of existing carbon-based negative electrode materials is only 372 mAh g -1 , which seriously limits the further improvement of the energy density of lithium ion batteries. In comparison, Si negative electrode with higher specific capacity has entered the field of view of people, and in order to overcome the problem of poor cycle stability of pure silicon negative electrode material, Si / C, SiO x / C, SiOC and other materials have been widely studied. SiOC material composed of conductive carbon framework and nano SiO x C y has the advantages of high capacity and cycle stability, and has high application value.

[0003] There are many deficiencies in the current related patents, for example: patent CN112420993A discloses a lithium battery SiOC@ nitrogen-doped carbon fiber composite negative electrode and preparation method, which introduces a method of combining SiOC material with electrostatic spinning film. This method is relatively complex and has high cost; patent CN108365184A discloses a carbon-rich porous SiOC negative electrode material for lithium ion batteries and a preparation method thereof, wherein the SiOC negative electrode material prepared has a first efficiency of only 68% at most, resulting in a low reversible capacity. At the same time, patent CN114057178A discloses a preparation method and application of nano composite carbon spheres, and the SiOC composite carbon spheres also have the problems of low first efficiency and reversible capacity and relatively poor rate performance. The above problems seriously affect the application prospect of such materials, and the problem needs to be solved urgently. SUMMARY

[0004] The present application solves the problems existing in the prior art, and provides a novel modified SiOCN material and application thereof in the field of energy storage devices. The preparation method of the novel modified SiOCN material is simple and green, and the composition content of the SiOCN material can be controlled. When the SiOCN material is used as a negative electrode material of a lithium ion battery, the introduction of metal and the control of carbon content can effectively improve the electrical conductivity of the SiOCN material, enhance the electrochemical reaction kinetics inside the material, improve the reversible capacity of the material, and obtain excellent rate performance and cycle stability.

[0005] The present application aims to provide a novel modified SiOCN material, which is prepared by the following steps: reacting amino-containing organosiloxane with organic aldehyde compound, metal ion-containing organic aldehyde compound, organic polyacid compound or metal salt thereof, and metal organic alkoxyl compound to prepare a metal-containing precursor, and then calcining under the protection of inert gas to obtain the modified SiOCN material.

[0006] The carbon content of the modified SiOCN material obtained by the present application is 10-50wt%.

[0007] Preferably, the amino-containing organosiloxane is selected from one or more of gamma-aminopropyltrimethoxysilane, gamma-aminopropyltriethoxysilane and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane; the organic aldehyde compound is selected from one or more of formaldehyde, glyoxal, glutaraldehyde, adipaldehyde, salicylaldehyde, terephthaldehyde and benzaldehyde; the organic polyacid compound is selected from one or more of citric acid, oxalic acid, malonic acid, succinic acid, terephthalic acid, trimesic acid, ethylenediaminetetraacetic acid and its metal salts, polystyrene sulfonic acid and polyacrylic acid and its metal salts, the metal ion in ethylenediaminetetraacetic acid and its metal salts, polystyrene sulfonic acid and polyacrylic acid and its metal salts being one or more of lithium, cobalt, nickel, manganese, iron, copper and zinc; the metal in the metal organoalkoxyl compound being one or more of titanium or germanium. Li is specifically lithium hydroxide, lithium acetate, lithium carbonate or an organolithium salt complex; Co is specifically one or more of inorganic and organic metal salts such as cobalt acetate, cobalt nitrate, cobalt chloride, etc.; Ni is specifically one or more of inorganic and organic metal salts such as nickel acetate, nickel nitrate, nickel chloride, etc.; Mn is specifically one or more of inorganic and organic metal salts such as manganese acetate, manganese nitrate, manganese chloride, etc.; Fe is specifically one or more of inorganic and organic metal salts such as iron oxalate, iron nitrate, iron chloride, etc.; Cu is specifically one or more of inorganic and organic metal salts such as copper acetate, copper nitrate, copper chloride, etc.; Zn is specifically one or more of inorganic and organic metal salts such as zinc acetate, zinc nitrate, etc.; when the metal in the metal organoalkoxyl compound is titanium, the organotitanium alkoxyl compound (titanium source) is tetrabutyl titanate, isopropyl titanate or tetraethyl titanate, and when the metal in the metal organoalkoxyl compound is germanium, the organogermanium alkoxyl compound (germanium source) is tetraethoxy germanium, etc.; wherein Li and Co, Ni, Fe, Mn, Cu, Zn, etc. transition metal sources can be complexed with a Schiff base or an acid, and the titanium source and the germanium source are co-hydrolyzed with siloxane.

[0008] Preferably, the calcination temperature of the calcined carbonization is 700-1300°C, the calcination time is 2-6h, and the molar ratio of the metal element to the silicon element in the amino-containing organosiloxane is 0.05:1-0.2:1. The inert gas is argon or nitrogen.

[0009] Further preferably, the molar ratio of the metal element Li to Si in the amino-containing organosiloxane is 1:1-1:5; the molar ratio of the metal element Ti to Si in the amino-containing organosiloxane is 1:20-1:5; the molar ratio of the transition metal element (Co, Ni, Fe, Mn, Cu or Zn) to Si in the amino-containing organosiloxane is 1:8-1:2; and the molar ratio of the metal element Ge to Si in the amino-containing organosiloxane is 1:10-1:1. By adding different proportions of metal sources, the content of the new type of composite material can be adjusted, thereby optimizing the material.

[0010] Further preferably, the SiOCN material is prepared by the following steps: reacting amino-containing organosiloxane with metal ion-containing organic aldehyde compound or metal salt of organic polyacid, hydrolyzing to form metal-containing organic Schiff base SiO2 precursor or metal-containing organic amino-carboxylate SiO2 precursor, calcining and carbonizing under inert gas protection to obtain the novel modified SiOCN material.

[0011] The product of the reaction of amino-containing organosiloxane with metal complex of organic aldehyde is shown in formula I below, R refers to N, O-containing organic aldehyde that can be complexed with metal, and M is metal ion:

[0012]

[0013] Further preferably, the SiOCN material is prepared by the following steps: 1) dissolving metal element salt (Li salt, Co salt, Ni salt, Mn salt, Fe salt, Cu salt or Zn salt) and organic aldehyde in ethanol and stirring to uniformity, mixing amino-containing organosiloxane ethanol solution with the above solution to obtain a mixed solution; 2) dropping the mixed solution into aqueous solution containing ammonia water to make the pH value of the reaction solution 8-13, and stirring to obtain metal element-containing Schiff base SiO2 precursor; 3) filtering and drying the above product, and calcining the dried precursor under inert gas protection to obtain metal element-modified SiOCN material. The molar ratio of aldehyde group in organic aldehyde to amino group in amino-containing organosiloxane is 0.5:1-4:1, the molar ratio of metal element Li to Si in amino-containing organosiloxane is 1:1-1:5, and the molar ratio of transition metal element (Co, Ni, Fe, Mn, Cu or Zn) to Si in amino-containing organosiloxane is 1:8-1:2. The concentration of metal element in ethanol is 0.01-0.015 mol / L -1 The concentration of organic aldehyde dissolved in ethanol is 0.01-1 mol / L -1 The concentration of amino-containing organosiloxane in the amino-containing organosiloxane ethanol solution is 0.1-0.5 mol / L -1 .

[0014] The product of the reaction of amino-containing organosiloxane with metal complex of organic aldehyde is shown in formula I below, R refers to N, O-containing organic aldehyde that can be complexed with metal, and M is metal ion:

[0015] The product of the reaction of amino-containing organosiloxane with metal complex of organic aldehyde is shown in formula I below, R refers to N, O-containing organic aldehyde that can be complexed with metal, and M is metal ion:

[0016]

[0017]

[0018] More preferably, the SiOCN material is prepared by the following steps: 1) dissolving organic polycarboxylic acid, ammonia, and metal element salt (Li salt, Ti salt, Co salt, Ni salt, Mn salt, Fe salt, Cu salt, or Zn salt) in an aqueous solution of ethanol, so that the pH value of the solution is 8-13; 2) mixing with an amino-containing organosiloxane ethanol solution under vigorous stirring to obtain a precursor; and 3) drying the precursor after removing the solvent, and calcining under inert gas protection to obtain a metal element-modified SiOCN material.

[0019] The molar ratio of carboxyl in the organic polycarboxylic acid to amino in the amino-containing organosiloxane is 0.5:1-6:1, the concentration of the organic polycarboxylic acid in the ethanol solution is 0.01-5 mol / L -1 , the molar ratio of metal element Li to Si in the amino-containing organosiloxane is 1:1-1:5, the molar ratio of transition metal element (Co, Ni, Fe, Mn, Cu, or Zn) to Si in the amino-containing organosiloxane is 1:8-1:2, and the concentration of the metal element in the ethanol is 0.4-0.5 mol / L -1 The concentration of the organic polycarboxylic acid in the ethanol is 0.2-0.3 mol / L -1 The concentration of the amino-containing organosiloxane in the amino-containing organosiloxane ethanol solution is 0.05-0.30 mol / L -1 .

[0020] More preferably, the SiOCN material is prepared by the following steps: introducing an organotitanoxane compound or an organogermanoxane compound into a co-hydrolysis reaction of the amino-containing organosiloxane and an organic aldehyde or an organic polycarboxylic acid to generate a titanium- or germanium-containing organic SiO2 precursor, and calcining under inert gas protection to obtain a novel modified SiOCN material.

[0021] The reaction is carried out in a mixed system of water and ethanol solution.

[0022] The titanium- or germanium-containing organic SiO2 precursor is shown in the following formula III, and M is Ti or Ge:

[0023]

[0024] Further preferably, the SiOCN material is prepared by the following steps: 1) mixing an ethanol solution containing organic polyacid (organic aldehyde), organic titanium alkoxide compound (organic germanium alkoxide compound) with an ethanol solution containing amino organosiloxane; 2) adding deionized water under vigorous stirring, the molar ratio of deionized water to amino organosiloxane being 3:1-50:1, and continuing to react for 4-5 h to obtain a titanium (germanium)-containing organic SiO2 precursor; 3) filtering and drying the above product, and calcining under inert gas protection to obtain a titanium (germanium)-modified SiOCN material. In the above process, the molar ratio of aldehyde groups in the organic aldehyde to amino groups in the amino organosiloxane is 0.5:1-4:1, the molar ratio of carboxyl groups in the organic polyacid to amino groups in the amino organosiloxane is 0.5:1-6:1, the concentration of the organic aldehyde in the ethanol solution is 0.01-1 mol / L -1 , the concentration of the organic polyacid in the ethanol solution is 0.01-5 mol / L -1 , and the concentration of the ethanol solution containing the amino organosiloxane is 0.02-0.5 mol / L -1 . The molar ratio of the metal element Ti to Si in the amino organosiloxane is 1:20-1:5, and the molar ratio of the metal element Ge to Si in the amino organosiloxane is 1:10-1:1.

[0025] Further preferably, the SiOCN material is prepared by the following steps: the amino organosiloxane is reacted with the organic polyacid in an organic solvent to produce an organic amino-carboxylic acid hydrogen bond complex, the organic amino-carboxylic acid hydrogen bond complex is hydrolyzed to form an organic SiO2 precursor, and the organic SiO2 precursor is calcined and carbonized under inert gas protection to obtain a novel modified SiOCN material.

[0026] The organic amino-carboxylic acid hydrogen bond complex is shown in the following formula IV, and R represents the organic polyacid:

[0027]

[0028] Further preferably, the SiOCN material is prepared by the following steps: 1) mixing an ethanol solution containing organic polyacid (organic aldehyde), organic titanium alkoxide compound (organic germanium alkoxide compound) with an ethanol solution containing amino organosiloxane; 2) adding deionized water under vigorous stirring, the molar ratio of deionized water to amino organosiloxane being 3:1-50:1, and continuing to react for 4-5 h to obtain a titanium (germanium)-containing organic SiO2 precursor; 3) filtering and drying the above product, and calcining under inert gas protection to obtain a titanium (germanium)-modified SiOCN material. In the above process, the molar ratio of aldehyde groups in the organic aldehyde to amino groups in the amino organosiloxane is 0.5:1-4:1, the molar ratio of carboxyl groups in the organic polyacid to amino groups in the amino organosiloxane is 0.5:1-6:1, the concentration of the organic aldehyde in the ethanol solution is 0.01-1 mol / L -1 , the concentration of the organic polyacid in the ethanol solution is 0.01-5 mol / L -1 .

[0029] Preferably, the molar ratio of aldehyde groups in the organic aldehyde compound or metal ion-containing organic aldehyde compound to the amino groups in the amino-containing organosiloxane is 0.5:1-4:1, and the molar ratio of carboxyl groups in the organic polyacid compound or metal salt thereof to the amino groups in the amino-containing organosiloxane is 0.5:1-6:1. The concentration of the reactant of the organic aldehyde compound or metal ion-containing organic aldehyde compound in the solution is 0.01-1 mol / L -1 The concentration of the reactant of the organic polyacid compound or metal salt thereof in the solution is 0.01-5 mol / L -1 The final composition of the material can be optimized by changing the types and ratios of the reactants.

[0030] The application also protects the application of the novel modified SiOCN material in the field of energy storage devices. Preferably, as a negative electrode material of a lithium ion battery. The SiOCN material provided in the application improves the first coulomb efficiency, reversible capacity and rate performance of the negative electrode material, and uses a more green and lower cost process. The material is mainly used as a negative electrode material in the field of lithium ion batteries and the like, and has a high reversible capacity and good rate performance and cycle stability through the introduction of a metal or the regulation of the carbon content.

[0031] Compared with the prior art, the application has the following advantages:

[0032] 1. The precursor is prepared by using a water-alcohol mixed reaction system in the application, the reaction conditions are mild, high temperature and high pressure are not required, and the material preparation process is simple and green.

[0033] 2. The composition of the novel modified SiOCN material prepared in the application is adjustable, and the above characteristics can be adjusted by changing the types and ratios of raw materials, calcination temperature and the like.

[0034] 3. The metal and its compound can effectively improve the electrical conductivity of the SiOCN material and enhance the electrochemical reaction kinetics in the material, improve the reversible capacity of the material, and obtain excellent rate performance and cycle stability. DETAILED DESCRIPTION

[0035] Figure 1 Structural formula of the Schiff base SiO2 precursor containing Co prepared in Examples 1 and 2;

[0036] Figure 2 SEM picture of the metal Co modified SiOCN material prepared in Example 1;

[0037] Figure 3 Charge-discharge specific capacity-voltage curve (0.2 A / g cycle charge-discharge) of the metal Co modified SiOCN material prepared in Example 1;

[0038] Figure 4 SEM image of CoS modified SiOCN material prepared in Example 2;

[0039] Figure 5 Charge-discharge specific capacity vs. voltage plot (0.2 A / g cycled charge-discharge) of CoS modified SiOCN material prepared in Example 2;

[0040] Figure 6 Rate capacity comparison plot of Co and CoS modified SiOCN materials prepared in Examples 1 and 2 vs. pure SiOCN;

[0041] Figure 7 TEM image of Ti modified SiOCN material prepared in Example 3;

[0042] Figure 8 Rate reversible capacity comparison plot of SiOCN materials with different Ti contents prepared in Example 3;

[0043] Figure 9 High rate cycling performance test plot of SiOCN material with optimized Ti content prepared in Example 3;

[0044] Figure 10 Structural formula of Schiff base SiO2 precursor containing Ge, R refers to different aldehydes;

[0045] Figure 11 SEM image of Ge modified SiOCN material prepared in Example 4;

[0046] Figure 12 Cycling performance comparison plot of SiOCN materials with different Ge contents prepared in Example 4;

[0047] Figure 13 SEM image of Li modified SiOCN material in Example 5;

[0048] Figure 14 SEM image of Li modified SiOCN material in Example 6;

[0049] Figure 15 SEM image of modified SiOCN material in Example 7;

[0050] Figure 16 SEM image of modified SiOCN material in Example 8;

[0051] Figure 17 SEM image of modified SiOCN material in Example 9. DETAILED DESCRIPTION:

[0052] The following examples are further illustrations of the present application and are not intended to limit the present application in any way.

[0053] Unless otherwise defined, all terms used in the description and claims are to be interpreted in accordance with their ordinary meaning as understood by those skilled in the art. The professional terms used in the present application are only for the purpose of describing the specific embodiments and are not intended to limit the scope of protection of the present application. Unless otherwise specified, the experimental materials and reagents used in the present application are commercially available products commonly used in the art.

[0054] Example 1

[0055] The preparation of the metal Co modified SiOCN material proposed in the present embodiment is carried out according to the following steps:

[0056] 1) 0.0498 g of cobalt acetate and 0.098 g of salicylaldehyde are dissolved in 20 mL of ethanol and stirred, and 20 mL of an ethanol solution containing 0.187 g of N-(2-aminoethyl)-3- aminopropyltrimethoxysilane is mixed with the above solution by stirring; 2) it is dropped into a solution containing 4 mL of ammonia water in 60 mL of water and stirred for 4 h to obtain a Co-containing Schiff base SiO2 precursor (as shown in the structural formula Figure 1 ); 3) after the above product is filtered and dried, the dried precursor is placed in a corundum crucible and calcined in a tube furnace at 700℃ for 3 h, with a calcination temperature rising speed of 2℃ / min, to obtain a metal Co modified SiOCN material.

[0057] Characterization of the material: the prepared metal Co modified SiOCN material is subjected to XRD testing, and the results show that the material contains amorphous SiOCN and obvious peaks of metal Co, and SEM testing (as shown in Figure 2 ) shows that the material is spherical particles with a particle size of 0.5 um.

[0058] Electrochemical performance: the prepared material, acetylene black and sodium carboxymethyl cellulose are mixed uniformly in a ratio of 8:1:1 to form a slurry, which is coated on a copper foil, vacuum dried at 110℃ for 12 h, and then subjected to rolling, cutting and weighing to obtain a lithium ion battery negative electrode sheet, and the loading amount of the nanometer composite carbon spheres on the electrode sheet is 0.8 mg / cm 2 . The negative electrode sheet is assembled into a lithium ion battery, and the electrolyte of the lithium ion battery is 1M LiPF6 DMC / DEC / EMC containing 5% FEC as an additive, wherein the volume ratio of DMC / DEC / EMC is 1:1:1, the separator is Celgard-2325, and lithium sheet is used as the counter electrode. Electrochemical testing (as shown in Figure 3 ) shows that the first cycle coulombic efficiency is 56.8% and the initial specific discharge capacity is 663 mAh g -1The discharge specific capacity of the lithium ion battery is calculated according to the mass of the active substance (i.e. the composite material).

[0059] Example 2

[0060] The preparation of the CoS modified SiOCN material according to the present example was carried out according to the following steps:

[0061] 1) 0.0498 g of cobalt acetate and 0.098 g of salicylaldehyde were dissolved in 20 mL of ethanol and stirred, and 20 mL of an ethanol solution containing 0.187 g of N-(2-aminoethyl)-3- aminopropyltrimethoxysilane was mixed with the above solution by stirring; 2) The mixture was added dropwise into a solution of 4 mL of ammonia water in 60 mL of water and stirred for 4 h to obtain a Co-containing Schiff base SiO2 precursor; 3) The above product was filtered and dried, sulfur powder was placed upstream of a tube furnace under argon protection, the dried precursor was placed downstream, and calcination was carried out in the tube furnace at 700°C for 3 h at a calcination temperature rising speed of 2°C / min to obtain the CoS modified SiOCN material.

[0062] Characterization of the material: The prepared CoS modified SiOCN material was subjected to XRD testing, and the results showed that the material contained amorphous SiOCN and sharp CoS peaks. SEM testing (as shown in Figure 4 ) showed that the material was spherical particles with a particle size of 0.5 um.

[0063] Electrochemical performance: The prepared material, acetylene black and sodium carboxymethyl cellulose were mixed uniformly in a ratio of 8:1:1 to form a slurry, which was coated on a copper foil and vacuum dried at 110°C for 12 h. After rolling, cutting and weighing, a lithium ion battery negative electrode sheet was obtained, and the loading amount of the nanometer composite carbon spheres on the electrode sheet was 0.8 mg / cm 2 . The negative electrode sheet was assembled into a lithium ion battery, and the electrolyte of the lithium ion battery was 1M LiPF6 DMC / DEC / EMC containing 5% FEC as an additive, wherein the volume ratio of DMC / DEC / EMC was 1:1:1, the separator was Celgard-2325, and lithium sheet was used as the counter electrode. Electrochemical testing (as shown in Figure 5 ) showed that the first cycle coulombic efficiency was 68.5% and the first reversible specific capacity was 834 mAh g -1 at a current density of 0.2 A / g. The discharge specific capacity of the lithium ion battery was calculated according to the mass of the active substance (i.e. the composite material).

[0064] Comparative Example 1

[0065] The metal Co in the material obtained in Example 1 was removed with hydrochloric acid to obtain a SiOCN material.

[0066] The specific capacity comparison chart of the metal Co modified SiOCN material (Co@SiOCN) obtained from Example 1, the CoS modified SiOCN material ((CoS@SiOCN)) obtained from Example 2 and the SiOCN material obtained from Comparative Example 1 is shown in Figure 6 Figure 1. When Comparative Example 1 was used as the negative electrode, the first efficiency decreased to 50%, and the reversible specific capacity was 434 mAh g -1 , indicating that the introduction of Co improved the performance of SiOCN.

[0067] Example 3

[0068] The preparation of the Ti modified SiOCN material proposed in this example was carried out according to the following steps:

[0069] 1) 10 mL of an ethanol solution containing 0.318 g of citric acid and different amounts of tetrabutyl titanate was stirred with 10 mL of an ethanol solution containing 1.1 g of γ-aminopropyl triethoxysilane, wherein the molar ratio of Ti to Si in the γ-aminopropyl triethoxysilane was 1:5, 1:10 and 1:20, respectively; 2) 0.25 mL of deionized water was added under vigorous stirring, and the reaction was continued for 5 h to obtain a Ti-containing organic SiO2 precursor; 3) the above product was filtered and dried, and then calcined in a tube furnace under argon protection at 1050°C for 2 h, with a calcination temperature increase rate of 5°C / min, to obtain a Ti modified SiOCN material (SiTiOCN).

[0070] Characterization of the material: the Ti modified SiOCN material was subjected to XRD testing, and the results showed that the material was amorphous. SEM testing (as shown in Figure 7 Figure 2) showed that the material was spherical particles with a particle size of 1-5 um. The XRD results showed that the material was a TiO2 modified SiOCN material. TEM showed that Ti was uniformly distributed inside the material.

[0071] Electrochemical performance: the prepared material, acetylene black and sodium carboxymethyl cellulose were mixed uniformly in a mass ratio of 8:1:1 to form a slurry, which was coated on a copper foil and vacuum dried at 110°C for 12 h. After rolling, cutting and weighing, a lithium ion battery negative electrode sheet was obtained, and the loading amount of the nanometer composite carbon spheres on the electrode sheet was 0.8 mg / cm 2 . The negative electrode sheet was assembled into a lithium ion battery, and the lithium ion battery electrolyte was 1M LiPF6 DMC / DEC / EMC with 5% FEC as an additive, wherein the volume ratio of DMC / DEC / EMC was 1:1:1, the separator was Celgard-2325, and lithium sheet was used as the counter electrode. Electrochemical testing (as shown in Figure 8 Figure 3) showed that at a current density of 0.2 A / g, the first cycle coulombic efficiency was 76.5%, and the first reversible specific capacity was 951 mAh g -1The discharge specific capacity of the lithium ion battery is calculated according to the mass of the effective substance (i.e. the composite material); Figure 8 and Figure 9 The results show that the introduction of an appropriate amount of Ti effectively improves the rate performance of the material.

[0072] Comparative Example 2

[0073] The same as Example 3, except that no Ti source is added to obtain a SiOCN material.

[0074] The rate reversible capacity of the Ti-modified SiOCN material obtained in Example 3 and the SiOCN material obtained in Comparative Example 2 is compared in the graph shown in Figure 8 When Comparative Example 2 is used as the negative electrode, the first efficiency is reduced to 69%, and the reversible specific capacity is 850 mAh g -1 , indicating that the introduction of Ti improves the performance of the SiOCN material.

[0075] Example 4

[0076] The preparation of the Ge-modified SiOCN material proposed in this example is carried out according to the following steps:

[0077] 1) Different amounts of tetraethoxygermanium and 1 g of glutaraldehyde are dispersed in 5 mL of an ethanol solution, and mixed with a 35 mL ethanol solution containing 1.1 g of γ-aminopropyltriethoxysilane under stirring, wherein the molar ratio of Ge to Si in the γ-aminopropyltriethoxysilane is 1:1, 1:2, and 1:10, respectively; 2) quickly added to 90 mL of water under stirring, and continue to react for 4 h to obtain a Schiff base SiO2 precursor containing Ge; 3) after the above product is filtered and dried, calcination is carried out under nitrogen protection in a tube furnace at 1000°C for 2 h, with a calcination temperature increasing speed of 5°C / min, to obtain a Ge-modified SiOCN material.

[0078] Characterization of the material: SEM testing (as shown in Figure 11 ) of the Ge-modified SiOCN material shows that the material is spherical particles with a particle size of 0.1-0.2 μm, and XRD results show that it is a material modified by metallic germanium.

[0079] Electrochemical performance: after the prepared material, acetylene black, and sodium carboxymethyl cellulose are mixed uniformly in a ratio of 8:1:1 to form a slurry, which is coated on a copper foil, vacuum dried at 110°C for 12 h, and then subjected to rolling, cutting, and weighing, a lithium ion battery negative electrode sheet is obtained, and the loading amount of the nanometer composite carbon spheres on the electrode sheet is 0.8 mg / cm 2The negative electrode sheet is assembled into a lithium ion battery, the electrolyte of the lithium ion battery is DMC / DEC / EMC with a concentration of 1M LiPF6, containing 5% FEC as an additive, wherein the volume ratio of DMC / DEC / EMC is 1:1:1, the separator is Celgard-2325, and a lithium sheet is used as the counter electrode. Electrochemical tests (such as Figure 12 indicate that the first cycle coulombic efficiency is 72% and the first reversible specific capacity is 980 mAh g-1 at a current density of 0.2 A / g. -1 The discharge specific capacity of the lithium ion battery is calculated according to the mass of the effective substance (i.e., the composite material).

[0080] Example 5

[0081] The preparation of the Li-modified SiOCN material coordinated by organic acid according to the present embodiment includes the following steps:

[0082] 1) Dissolve 0.73 g of ethylenediaminetetraacetic acid, 0.5 mL of ammonia water, and 0.1 g of lithium hydroxide in 13 mL of an ethanol aqueous solution, wherein the volume ratio of ethanol to water in the ethanol aqueous solution is 10:3; 2) mix with 20 mL of an ethanol solution containing 1.1 g of γ-aminopropyl triethoxysilane under vigorous stirring, and continue to react for 5 h to obtain a precursor; 3) after removing the solvent and drying the above product, calcine it in a tube furnace at 1000°C for 2 h under argon protection, wherein the calcination temperature increasing speed is 5°C / min, to obtain the Li-modified SiOCN material coordinated by organic acid.

[0083] Material characterization: the Li-modified SiOCN material is subjected to SEM testing (as shown in Figure 13 , it can be known that the material is a blocky particle, and EDS analysis shows that the element content is Si: 21 wt%, O: 31 wt%, C: 48 wt%, and the content of N element is less than 1 wt%, which is attributed to the carbon element.

[0084] Example 6

[0085] The preparation of the Li-modified SiOCN material prepared by Schiff base reaction according to the present embodiment includes the following steps:

[0086] 1) Dissolve 0.005 g of lithium acetate and 1 g of glutaraldehyde in 40 mL of an ethanol solution; 2) mix with 90 mL of an aqueous solution containing 1.1 g of γ-aminopropyl triethoxysilane under vigorous stirring, and continue to react for 4 h to obtain a Li-containing Schiff base SiO2 precursor; 3) after removing the solvent and drying the above product, calcine it in a tube furnace at 9000°C for 2 h under argon protection, wherein the calcination temperature increasing speed is 5°C / min, to obtain the Li-modified SiOCN material.

[0087] Material characterization: the Li-modified SiOCN material is subjected to SEM testing (as shown inFigure 14 As shown in FIG. 1, the material is nanospherical particles.

[0088] Example 7

[0089] The preparation of the modified SiOCN material proposed in this example is carried out according to the following steps:

[0090] 1) 2.98 g of a polystyrene sulfonic acid (30%) aqueous solution is mixed with 20 mL of an ethanol solution containing 1.1 g of γ-aminopropyl triethoxysilane under vigorous stirring, and the reaction is continued for 30 min to obtain a precursor; 2) After the solvent of the above product is removed and dried, the product is calcined in a tube furnace under argon protection at 1000°C for 2 h, with a calcination temperature increasing rate of 5°C / min, to obtain the modified SiOCN material.

[0091] Characterization of the material: the modified SiOCN material is subjected to SEM testing (as shown in FIG. 1), and it can be known that the material is a blocky particle. EDS analysis shows that the element content is Si: 43wt%, O: 44wt%, C: 12wt%, and N: 1wt%. Figure 15

[0092] Example 8

[0093] The preparation of the modified SiOCN material proposed in this example is carried out according to the following steps:

[0094] 1) 0.355 g of a polyacrylic acid aqueous solution is mixed with 20 mL of an ethanol solution containing 1.1 g of γ-aminopropyl triethoxysilane under vigorous stirring, and the reaction is continued for 5 h to obtain a precursor; 2) After the solvent of the above product is removed and dried, the product is calcined in a tube furnace under argon protection at 1000°C for 2 h, with a calcination temperature increasing rate of 5°C / min, to obtain the modified SiOCN material.

[0095] Characterization of the material: the modified SiOCN material is subjected to SEM testing (as shown in FIG. 1), and it can be known that the material is a blocky particle. EDS analysis shows that the element content is Si: 43wt%, O: 44wt%, C: 12wt%, and N: 1wt%. Figure 16

[0096] Example 9

[0097] The preparation of the modified SiOCN material proposed in this example is carried out according to the following steps:

[0098] ​​1) 0.37 g ethylenediaminetetraacetic acid, 0.5 ammonia water in 3 mL water solution was mixed with 20 mL ethanol solution containing 1.1 g of γ-aminopropyltriethoxysilane under vigorous stirring, and the reaction was continued for 5 h to obtain the precursor; 2) After the above product was dried by removing the solvent, it was calcined in a tube furnace at 1000 °C for 2 h under argon protection, with a heating rate of 5 °C / min, to obtain the modified SiOCN material.

[0099] Characterization of the material: The modified SiOCN material was tested by SEM (as shown in FIG. 1), and it was found that the material was blocky particles. The elemental content was Si: 44 wt%, O: 46 wt%, C: 8 wt%, and N: 1 wt%. Figure 17

[0100] Example 10

[0101] The same as Example 1, except that the organic aldehyde was glyoxal, the molar ratio of the aldehyde group in glyoxal to the amino group in N-(2-aminoethyl)-3- aminopropyltrimethoxysilane was 0.5:1, the metal element was Li, the molar ratio of Li to Si in N-(2-aminoethyl)-3-aminopropyltrimethoxysilane was 1:1; the concentration of Li in ethanol was 0.01 mol / L -1 , the concentration of glyoxal dissolved in ethanol was 0.01 mol / L -1 , and the concentration of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane in the ethanol solution of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane was 0.35 mol / L -1 . The calcination temperature of the carbonized calcination was 700 °C, and the calcination time was 6 h.

[0102] Example 11

[0103] The same as Example 1, except that the organic aldehyde was glyoxal, the molar ratio of the aldehyde group in glyoxal to the amino group in N-(2-aminoethyl)-3- aminopropyltrimethoxysilane was 4:1, the metal element was Li, the molar ratio of Li to Si in N-(2-aminoethyl)-3-aminopropyltrimethoxysilane was 1:5; the concentration of Li in ethanol was 0.015 mol / L -1 , the concentration of glyoxal dissolved in ethanol was 1 mol / L -1 , and the concentration of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane in the ethanol solution of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane was 0.40 mol / L -1 . The calcination temperature of the carbonized calcination was 1300 °C, and the calcination time was 2 h.

[0104] Example 12

[0105] ​The same as Example 3, except that the molar ratio of carboxyl groups in citric acid to amino groups in γ-aminopropyltriethoxysilane was 0.5:1, the concentration of citric acid in ethanol solution was 0.01 mol / L -1 , the concentration of γ-aminopropyltriethoxysilane in ethanol solution was 0.02 mol / L -1 . The molar ratio of metal element Ti to Si in amino-containing organosiloxane was 1:20, the molar ratio of deionized water to γ-aminopropyltriethoxysilane was 3:1, the calcination temperature of calcination carbonization was 700°C, and the calcination time was 6h.

[0106] Example 13

[0107] The same as Example 3, except that the molar ratio of carboxyl groups in citric acid to amino groups in γ-aminopropyltriethoxysilane was 6:1, the concentration of citric acid in ethanol solution was 5 mol / L -1 , the concentration of γ-aminopropyltriethoxysilane in ethanol solution was 0.5 mol / L -1 . The molar ratio of metal element Ti to Si in amino-containing organosiloxane was 1:5, the molar ratio of deionized water to γ-aminopropyltriethoxysilane was 10:1, the calcination temperature of calcination carbonization was 1300°C, and the calcination time was 2h.

[0108] Example 14

[0109] The same as Example 5, except that the organic polyacid was malonic acid, the molar ratio of carboxyl groups in malonic acid to amino groups in γ-aminopropyltriethoxysilane was 0.5:1, and the concentration of malonic acid in ethanol solution was 0.01 mol / L -1 . The salt of metal element was nickel nitrate, the molar ratio of Ni to Si in γ-aminopropyltriethoxysilane was 1:8, and the concentration of Ni in ethanol was 0.4 mol / L -1 . The concentration of malonic acid dissolved in ethanol was 0.2 mol / L -1 . The concentration of γ-aminopropyltriethoxysilane in the ethanol solution of γ-aminopropyltriethoxysilane was 0.20 mol / L -1 . The calcination temperature of calcination carbonization was 700°C, and the calcination time was 6h.

[0110] Example 15

[0111] The same as Example 5, except that the organic polyacid was malonic acid, the molar ratio of carboxyl groups in malonic acid to amino groups in γ-aminopropyltriethoxysilane was 6:1, and the concentration of malonic acid in ethanol solution was 5 mol / L -1 . The salt of metal element was nickel nitrate, the molar ratio of Ni to Si in γ-aminopropyltriethoxysilane was 1:2, and the concentration of Ni in ethanol was 0.5 mol / L-1 Malonic acid was dissolved in ethanol at a concentration of 0.3 mol L -1 The concentration of γ-aminopropyltriethoxysilane in the ethanol solution was 0.25 mol L -1 The calcination temperature of the calcined carbonized product was 1300℃, and the calcination time was 2h.

[0112] The above examples are only used to help understand the technical solutions of the present application and its core idea. It should be pointed out that for those skilled in the art, without departing from the principles of the present application, the present application can be improved and modified in several ways, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A novel modified SiOCN material, characterized in that, The modified SiOCN material is prepared by the following steps: the amino-containing organosiloxane is reacted with an organic aldehyde compound, a metal ion-containing organic aldehyde compound, an organic polyacid compound or a metal salt thereof, and a metal organoalkoxy compound to prepare a metal-containing precursor, and then the precursor is calcined under inert gas protection to obtain the modified SiOCN material; the amino-containing organosiloxane is selected from one or more of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane; the organic aldehyde compound is selected from one or more of formaldehyde, glyoxal, glutaraldehyde, adipaldehyde, salicylaldehyde, terephthaldehyde, and benzaldehyde; the organic polyacid compound is selected from one or more of citric acid, oxalic acid, malonic acid, succinic acid, terephthalic acid, trimesic acid, ethylenediaminetetraacetic acid and a metal salt thereof, polystyrene sulfonic acid, and polyacrylic acid and a metal salt thereof, the metal ion in the ethylenediaminetetraacetic acid and the metal salt thereof, the polystyrene sulfonic acid, and the polyacrylic acid and the metal salt thereof is one or more of lithium, cobalt, nickel, manganese, iron, copper, and zinc, and the metal in the metal organoalkoxy compound is one or more of titanium and germanium; the amino-containing organosiloxane is reacted with the metal ion-containing organic aldehyde compound or the metal salt of the organic polyacid to hydrolytically generate a metal-containing organic Schiff base precursor or a metal-containing organic amino-carboxylate precursor.

2. The novel modified SiOCN material according to claim 1, characterized in that, The modified SiOCN material is prepared by the following steps: the amino-containing organosiloxane is reacted with an organic aldehyde compound or an organic polyacid compound, and a metal organoalkoxy compound is introduced to generate a titanium- or germanium-containing organic SiO2 precursor through co-hydrolysis, and the precursor is calcined and carbonized under inert gas protection to obtain the novel modified SiOCN material.

3. The novel modified SiOCN material according to claim 1, characterized in that, The modified SiOCN material is prepared by the following steps: the amino-containing organosiloxane is reacted with an organic polyacid to generate an organic amino-carboxylic acid hydrogen bond complex, and then the complex is hydrolyzed to generate a SiOCN precursor, and the precursor is calcined under inert gas protection to obtain a modified SiOCN material with adjustable carbon content.

4. The novel modified SiOCN material according to any one of claims 1 to 3, characterized in that, The molar ratio of the aldehyde group in the organic aldehyde compound or the metal ion-containing organic aldehyde compound to the amino group in the amino-containing organosiloxane is 0.5:1 to 4:1, and the molar ratio of the carboxyl group in the organic polyacid compound or the metal salt thereof to the amino group in the amino-containing organosiloxane is 0.5:1 to 6:

1.

5. The novel modified SiOCN material according to any one of claims 1-3, characterized in that, The calcination temperature for the calcination and carbonization is 700°C to 1300°C, the calcination time is 2 to 6 hours, and the molar ratio of the metal element to the silicon element in the amino-containing organosiloxane is 0.05:1 to 0.2:

1.

6. Application of the novel modified SiOCN material of any one of claims 1 to 3 in the field of energy storage devices.

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