CN110797208A - Preparation method and application of electrode material - Google Patents

Abstract

The invention relates to the technical field of electrode materials, and in particular to a preparation method and application of an electrode material. The invention increases double metal hydroxide nanosheets by straight-chain dicarboxylic acid disodium salt or conjugated polycarboxylic acid sodium salt The interlayer spacing can be improved to achieve improved OH ^- interlayer diffusion kinetics, resulting in electrode materials. According to the records of the examples, the electrode material still has a high specific capacity of ≥173 F/g at a current density of 150 A/g; and the method has the advantages of controllable material composition, easy mass production, and low cost.

Description

A kind of preparation method and application of electrode material

technical field

The invention relates to the technical field of electrode materials, in particular to a preparation method and application of an electrode material.

Background technique

Supercapacitors have the advantages of high power density and long cycle life, and are widely used in automobiles, electronic devices and efficient utilization of renewable energy. However, the low energy density of supercapacitors greatly limits its application range and stimulates the research enthusiasm to develop supercapacitor electrode materials with high energy density. In recent years, researchers have found that transition metal-based materials have high theoretical energy density, and can store and release charges through the occurrence of Faradaic reactions. However, the kinetics of charge transport in the Faradaic reaction of such materials is slow, resulting in poor capacity and rate performance. Therefore, by improving the charge transport kinetics of the electrode material, its rate capability can be greatly improved.

Layered double metal hydroxides (LDHs) are composed of positively charged double metal hydroxide layers, negatively charged interlayer anions and partially intercalated water molecules, and their general formula is [M ²⁺ _1-x M ^{3 +} _x (OH) ₂ ] ^x+ [A ^n- _x/n ] ^x- mH ₂ O, where M ²⁺ or M ³⁺ represents divalent (eg Ni ²⁺ , Mg ²⁺ , Co ²⁺ , Mn ^{2 +} , Zn ²⁺ , etc.) or trivalent (such as Al ³⁺ , Cr ³⁺ , Fe ³⁺ , etc.) metal ions, ^An- represents an anion with -n valence, x represents the charge density of the laminate by divalent and trivalent The ratio of valence metal ions is determined (eg x=M ³⁺ /(M ²⁺ +M ^{3 +} )). In alkaline electrolyte, LDHs undergo a reversible Faradaic reaction (i.e., the reversible transition between hydroxide and oxyhydroxide) for electrochemical energy storage, and have a high theoretical specific capacity; LDHs also have the advantages of simple synthesis and flexible components. It is a class of potential energy storage materials and is widely used in the field of supercapacitors.

However, in general, the interlayer spacing of LDHs is small, which is not conducive to the diffusion of OH ^between the layers during the electrochemical energy storage process, limiting the extent to which the electrode material participates in the reaction. Therefore, LDHs exhibit poor capacity and rate performance.

SUMMARY OF THE INVENTION

In order to solve the above technical problems, the present invention provides a preparation method and application of an electrode material.

In order to achieve the above-mentioned purpose of the invention, the present invention provides the following specific technical solutions:

The invention provides a preparation method of an electrode material, comprising the following steps:

Mixing the intercalation solution and the layered double metal hydroxide to carry out an intercalation reaction to obtain an electrode material;

The intercalation solution is a straight-chain dicarboxylic acid disodium salt solution or a conjugated polycarboxylic acid sodium salt solution.

Preferably, the layered double metal hydroxide is in the shape of a curd that is cross-connected by double metal hydroxide nanosheets;

The interlayer spacing of the double metal hydroxide nanosheets in the layered double metal hydroxide is 0.8-0.85 nm;

The electrode material is in the shape of a flower ball that is cross-connected by double metal hydroxide nanosheets;

The interlayer spacing of the double metal hydroxide nanosheets in the electrode material is 0.7-1.3 nm.

Preferably, the concentration of the linear dicarboxylic acid disodium salt solution or the conjugated polycarboxylic acid sodium salt solution is independently (0.08-0.12) mol/L.

Preferably, the mass ratio of the solute in the straight-chain dicarboxylic acid disodium salt solution or the conjugated polycarboxylic acid sodium salt solution to the layered double metal hydroxide is independently (5-40):1.

Preferably, the linear dicarboxylic acid disodium salt in the linear dicarboxylic acid disodium salt solution is disodium oxalate, disodium succinate, disodium glutarate, disodium adipate, heptane One or more of disodium diacid, disodium suberate, disodium azelaate, disodium sebacate, disodium n-undecanedicarboxylate and disodium n-dodecanedicarboxylate.

Preferably, the conjugated polycarboxylic acid sodium salt in the conjugated polycarboxylic acid sodium salt solution is trisodium 1,3,5-benzenetricarboxylic acid, tetrasodium 1,2,4,5-benzenetetracarboxylic acid , disodium 1,4-terephthalate, disodium 1,4-naphthalate, disodium 2,6-naphthalate, tetrasodium 3,4,9,10-pyrenetetracarboxylate and 4,4' - One or more of disodium biphthalate.

Preferably, the temperature of the intercalation reaction is 60˜100° C., and the time of the intercalation reaction is 12˜72 h.

Preferably, the preparation method of the layered double metal hydroxide comprises the following steps:

Mix the aqueous solution of metal nitrate solution, oxalate and hexamethylenetetramine, carry out precipitation reaction to obtain layered double metal hydroxide;

The metal nitrate solution is a divalent metal nitrate solution or a mixed solution of a divalent metal nitrate and a trivalent metal nitrate.

Preferably, when the metal nitrate solution is a mixed solution of divalent metal nitrate and trivalent metal nitrate:

The divalent metal in the divalent metal nitrate is Ni ²⁺ , Co ²⁺ , Mn ²⁺ or Zn ²⁺ ; the trivalent metal in the trivalent metal nitrate is Al ³⁺ , Cr ³⁺ or Fe ³⁺ ;

When the metal nitrate solution is a divalent metal nitrate solution:

The divalent metal in the divalent metal nitrate is two of Ni ²⁺ , Co ²⁺ , Mn ²⁺ and Zn ²⁺ .

The present invention also provides the application of the electrode material prepared by the preparation method described in the above technical solution as an electrode material.

The invention provides a method for preparing an electrode material, comprising the following steps: mixing an intercalation solution and a layered double metal hydroxide, and performing an intercalation reaction to obtain an electrode material; the intercalation solution is a linear dicarboxylate Acid disodium salt solution or conjugated polycarboxylic acid sodium salt solution. In the present invention, the interlayer spacing of the double metal hydroxide nanosheet is increased by the straight-chain dicarboxylic acid disodium salt or the conjugated polycarboxylic acid sodium salt, thereby improving the OH ^- interlayer diffusion kinetics and obtaining the electrode material. According to the description of the examples, the electrode material still has a high specific capacity of ≥173 F/g at a current density of 150 A/g. And the method has the advantages of controllable material components, easy mass production, low cost and the like.

Description of drawings

Fig. 1 is the SEM image of the layered double metal hydroxide described in Example 1;

2 is a SEM image of the electrode material prepared in Example 1;

3 is the XRD patterns of the electrode materials prepared in Examples 1 to 7 and the layered double metal hydroxide prepared in Comparative Example 1;

4 is a graph showing the rate performance of the electrode materials prepared in Examples 1 to 7 and the layered double metal hydroxide prepared in Comparative Example 1;

5 is a graph showing the rate performance of the electrode material prepared in Example 6 and the layered double metal hydroxide prepared in Comparative Examples 2-9.

Detailed ways

The invention provides a preparation method of an electrode material, comprising the following steps:

Mixing the intercalation solution and the layered double metal hydroxide to carry out an intercalation reaction to obtain an electrode material;

The intercalation solution is a straight-chain dicarboxylic acid disodium salt solution or a conjugated polycarboxylic acid sodium salt solution.

In the present invention, unless otherwise specified, all raw material components are commercially available products well known to those skilled in the art.

In the present invention, the intercalation solution is mixed with the layered double metal hydroxide, and the intercalation reaction is carried out to obtain the electrode material; the intercalation solution is a straight-chain dicarboxylic acid disodium salt solution or a conjugated polycarboxylic acid sodium salt solution.

In the present invention, the concentration of the linear dicarboxylic acid disodium salt solution or the conjugated polycarboxylic acid sodium salt solution is preferably (0.08-0.12) mol/L, more preferably (0.09-0.11) mol/L L, most preferably 0.10mol/L; the solvent of the straight-chain dicarboxylic acid disodium salt solution or the conjugated polycarboxylic acid sodium salt solution is preferably ultrapure water; the straight-chain dicarboxylate disodium salt solution The straight-chain dicarboxylic acid disodium salt in the salt solution is preferably disodium oxalate, disodium succinate, disodium glutarate, disodium adipate, disodium pimelic acid, disodium suberate, One or more of disodium diacid, disodium sebacate, disodium n-undecanedicarboxylate and disodium n-dodecanedicarboxylate; when the straight-chain dicarboxylate disodium salt is When two or more of the above-mentioned specific substances are selected, the present invention does not have any special limitation on the proportion of the specific substances, and the mixture is carried out according to any proportion. The conjugated polycarboxylic acid sodium salt in the conjugated polycarboxylic acid sodium salt solution is preferably trisodium 1,3,5-benzenetricarboxylic acid, tetrasodium 1,2,4,5-benzenetetracarboxylic acid, 1 , Disodium 4-terephthalate, disodium 1,4-naphthalene dicarboxylate, disodium 2,6-naphthalene dicarboxylate, tetrasodium 3,4,9,10-pyrenetetracarboxylate and 4,4'- One or more of disodium phthalate; when the conjugated polycarboxylic acid sodium salt is two or more of the above-mentioned specific selections, the present invention does not have any special restrictions on the proportioning of the specific substances , can be mixed according to any ratio.

In the present invention, the layered double metal hydroxide is cross-connected by double metal hydroxide nanosheets (as shown in FIG. 1 ), and the double metal hydroxide nanosheets in the layered double metal hydroxide The interlayer spacing is preferably 0.8 to 0.85 nm, more preferably 0.81 to 0.84 nm, and most preferably 0.82 nm. The interlayer anion in the layered double metal hydroxide is preferably nitrate ion.

In the present invention, the layered double metal hydroxide is preferably prepared by the following preparation method, and the preparation method includes the following steps:

Mixing the metal nitrate solution, the aqueous solution containing oxalate and hexamethylenetetramine, a precipitation reaction occurs to obtain a layered double metal hydroxide;

The metal nitrate solution is a mixed solution of divalent metal nitrate and trivalent metal nitrate or a divalent metal nitrate solution.

In the present invention, the solvent of the metal nitrate solution is preferably ultrapure water; when the metal nitrate solution is a mixed solution of divalent metal nitrate and trivalent metal nitrate: the divalent metal nitrate The divalent metal in is preferably Ni ²⁺ , Co ²⁺ , Mn ²⁺ or Zn ²⁺ ; the trivalent metal in the trivalent metal nitrate is preferably Al ³⁺ , Cr ³⁺ or Fe ³⁺ ; The molar ratio of the divalent metal nitrate to the trivalent metal nitrate is preferably (0.14-7):1, more preferably (2-7):1, most preferably 3:1; the divalent metal The concentration of nitrate in the metal nitrate solution is preferably 0.03-0.22 mol/L, more preferably 0.1-0.17 mol/L, and most preferably 0.15 mol/L.

When the metal nitrate solution is a divalent metal nitrate solution: the divalent metal in the divalent metal nitrate is preferably two of Ni ²⁺ , Co ²⁺ , Mn ²⁺ and Zn ²⁺ . In the present invention, the molar ratio of the two divalent metal nitrates is preferably (0.1-19):1, more preferably (5-9):1, most preferably 7:1; the divalent metal The total concentration of the divalent metal nitrate in the nitrate solution is preferably 0.05-0.4 mol/L, more preferably 0.1-0.3 mol/L, and most preferably 0.25 mol/L.

In the present invention, the concentration of hexamethylenetetramine in the aqueous solution containing oxalate and hexamethylenetetramine is preferably (0.8-1.2) mol/L, more preferably 1.0 mol/L; the The concentration of sodium oxalate in the aqueous solution of oxalate and hexamethylenetetramine is preferably (4.5 to 5.5) g/L, and more preferably 5.0 g/L.

In the present invention, the dosage ratio of the metal nitrate solution and the aqueous solution containing oxalate and hexamethylenetetramine is preferably (75-85) mL: (15-25) mL, more preferably 80 mL: 20 mL .

In the present invention, the specific process of mixing the metal nitrate solution and the aqueous solution containing oxalate and hexamethylenetetramine is preferably: after degassing and oxygenating the metal nitrate solution, in a stirring Under certain conditions, the solution is heated to 40-60° C., and the degassed aqueous solution containing sodium oxalate and hexamethylenetetramine is rapidly added.

In the present invention, the oxalate is preferably soluble oxalate, more preferably sodium oxalate or potassium oxalate; in the present invention, the function of the oxalate is to provide oxalate, which forms insoluble with metal ions Oxalate in water; the oxalate can be used as a nucleation center for the self-assembly of LDH nanosheets in the precipitation reaction, and finally grow to form LDHs with a curd-shaped morphology (product 1). Without the addition of oxalic acid, the resulting nanosheets are usually chaotically distributed, making it difficult to obtain curd-like morphologies. The hexamethylenetetramine is slowly hydrolyzed in water to generate hydroxide ions, which react with metal ions to generate layered double metal hydroxides.

In the present invention, the precipitation reaction is preferably carried out under stirring conditions, and the present invention does not have any special limitation on the stirring; the temperature of the precipitation reaction is preferably 95-100°C, more preferably 96-98°C; The time of the precipitation reaction is preferably 4-12 h, more preferably 6-8 h.

After the precipitation reaction is completed, the present invention preferably performs post-treatment on the product obtained by the precipitation reaction, and the post-treatment is preferably filtration, washing and drying; the present invention does not have any special limitation on the filtration, and adopts the method well known to those skilled in the art. The filtration process can be carried out; in the present invention, the washing is preferably fully washed with ultrapure water and absolute ethanol in turn; the present invention does not have any special limitation on the drying, and adopts the drying method well known to those skilled in the art. The process can proceed.

In the present invention, the mixing of the intercalation solution and the layered double metal hydroxide is preferably by adding the layered double metal hydroxide to the intercalation solution.

In the present invention, the mass ratio of the solute in the straight-chain dicarboxylic acid disodium salt solution or the conjugated polycarboxylic acid sodium salt solution to the layered double metal hydroxide is preferably (5-40):1 , more preferably (10-30):1, and most preferably (15-25):1.

In the present invention, the temperature of the intercalation reaction is preferably 60-100°C, more preferably 70-80°C; the time of the intercalation reaction is preferably 12-72h, more preferably 20-60h, and most preferably 30～50h.

After the intercalation reaction is completed, the present invention preferably performs post-treatment on the product system obtained after the reaction is completed; the post-treatment preferably includes sequentially cooling, filtering, washing and vacuum drying; the present invention has no method for the cooling and filtering. Any special limitation can be carried out by using the cooling and filtration process well-known to those skilled in the art; in the present invention, the washing is preferably carried out with ultrapure water and absolute ethanol in sequence; in the present invention, the The temperature of vacuum drying is preferably 75-85°C, more preferably 80°C, and the time of vacuum drying is preferably 10-15h, more preferably 12h.

In the present invention, the straight-chain dicarboxylic acid disodium salt or the conjugated polycarboxylic acid sodium salt can realize the regulation of the conductivity and interlayer spacing of the double metal hydroxide nanosheets, and use carboxylate ions to replace the layered NO ^3- ions between the double metal hydroxide material layers, so as to achieve the purpose of regulating the interlayer spacing. Due to the difference in size of the different carboxylate ions, the interlayer spacing of the final electrode material is also different.

In the present invention, the electrode material is cross-connected by double metal hydroxide nanosheets;

The interlayer spacing of the double metal hydroxide nanosheets in the electrode material is preferably 0.7-1.3 nm.

The present invention also provides the application of the electrode material prepared by the preparation method described in the above technical solution as an electrode material.

The preparation method and application of the electrode material provided by the present invention will be described in detail below with reference to the examples, but they should not be construed as limiting the protection scope of the present invention.

Example 1

A mixed solution of Ni(NO ₃ ) ₂ .6H ₂ O and Co(NO ₃ ) ₂ .6H ₂ O was provided (Ni(NO ₃ ) ₂ .6H ₂ O was 17.5 mmol, Co(NO ₃ ) ₂ .6H ₂ O is 2.5mmol, ultrapure water is 80mL), the aqueous solution of sodium oxalate and hexamethylenetetramine (sodium oxalate is 0.1g, hexamethylenetetramine is 20mmol, water is 20mL) and disodium succinate solution ( Disodium succinate is 10mmol, ultrapure water 100mL);

The mixed solution of Ni(NO ₃ ) ₂ ·6H ₂ O and Co(NO ₃ ) ₂ ·6H ₂ O was degassed and oxygenated, heated to 40°C under stirring, and the degassed sodium oxalate and The aqueous solution of hexamethylenetetramine is subjected to precipitation reaction (95℃, 6h) under stirring conditions, then cooled, filtered, fully washed with ultrapure water and absolute ethanol, and dried to obtain layered double metal hydroxide ;

The layered double metal hydroxide is subjected to SEM test, and the test result is shown in Figure 1. It can be seen from Figure 1 that the layer spacing of the double metal hydroxide is 0.82 nm;

After mixing 100 mg of the layered double metal hydroxide with disodium succinate solution, degassing and oxygenating, performing intercalation reaction (90°C, 24h), cooling, filtering, using ultrapure water and anhydrous Fully washed with ethanol and vacuum dried (80°C, 12h) to obtain electrode material;

The electrode material is tested by SEM, and the test result is shown in FIG. 2 . It can be seen from FIG. 2 that the interlayer spacing of the double metal hydroxide is 0.88 nm.

Example 2

The preparation method refers to Example 1, except that disodium adipate is used instead of disodium succinate in Example 1; the interlayer spacing of the double metal hydroxide in the electrode material is 0.95 nm.

Example 3

The preparation method refers to Example 1, except that disodium sebacate is used instead of disodium succinate in Example 1; the interlayer spacing of the double metal hydroxide in the electrode material is 1.02-1.29 nm.

Example 4

The preparation method refers to Example 1, with the difference that trisodium 1,3,5-benzenetricarboxylate is used instead of disodium succinate in Example 1; the interlayer spacing of the double metal hydroxide in the electrode material is 0.82 nm.

Example 5

The preparation method refers to Example 1, with the difference that disodium 2,6-naphthalenedicarboxylate is used instead of disodium succinate in Example 1; the interlayer spacing of the double metal hydroxide in the electrode material is 0.84 nm.

Example 6

The preparation method refers to Example 1, with the difference that disodium 1,4-terephthalate is used instead of disodium succinate in Example 1; the interlayer spacing of the double metal hydroxide in the electrode material is 0.91 nm.

Example 7

The preparation method refers to Example 1, the difference is that tetrasodium 3,4,9,10-pyrenetetracarboxylate is used instead of disodium succinate in Example 1; the interlayer spacing of the double metal hydroxide in the electrode material is 0.94 nm.

Comparative Example 1

The preparation method refers to Example 1, except that sodium carbonate is used instead of disodium succinate in Example 1; the interlayer spacing of the double metal hydroxide in the layered double metal hydroxide is 0.765 nm.

Comparative Examples 2 to 9

Comparative example 2 is hollow Ni-Al LDH microspheres: the preparation method refers to Chem.Mater., 2012, 24, 1192-1197;

Comparative example 3 is Ni-Co-Al LDH: the preparation method refers to Electrochim. Acta, 2017, 225, 263-271;

Comparative example 4 is Co-Al LDH/graphene: the preparation method refers to Adv.Funct.Mater., 2015, 25, 1648-1655;

Comparative example 5 is Co-Ni LDH/PEDOT:PSS: for the preparation method, refer to Adv.Funct.Mater., 2015, 25, 2745-2753;

Comparative example 6 is Ni-Fe LDH: the preparation method refers to J.Power Sources, 2016, 325, 675-681;

Comparative Example 7 is Ni-Co-Al LDH NPs/Ni-Co CH NWs: for the preparation method, refer to Adv. EnergyMater., 2014, 4, 1400761;

Comparative example 8 is C/Ni-Co LDH/Co ₉ S ₈ : the preparation method refers to Adv.Mater., 2017, 29, 1606814;

Comparative Example 9 is Ni-Co-Al LDH: for the preparation method, refer to Adv. Energy Mater., 2014, 4, 1301240.

test case

The electrode materials prepared in Examples 1 to 7 and the layered double metal hydroxide prepared in Comparative Example 1 were subjected to XRD test. The test results are shown in Figure 3. It can be seen from Figure 3 that the double metal hydroxide in the electrode material is The interlayer spacing of the material is 0.7 to 1.3 nm.

The electrode materials prepared in Examples 1-7 and the layered double metal hydroxides prepared in Comparative Examples 1-9 were tested for their energy storage performance in 6M KOH electrolyte, and the rate performance was tested. The test results are shown in Figure 4 and Figure 4 5 (Figure 4 is the rate performance curve of the products obtained from Examples 1 to 7 and Comparative Example 1; Figure 5 is the rate performance curve of the products obtained from Example 6 and Comparative Examples 2 to 9), according to Figure 4, the The specific capacities of the products obtained in Examples 1 to 7 and Comparative Example 1 at different current densities are summarized in Table 1:

Table 1 Specific capacities of the products obtained from Examples 1 to 7 and Comparative Example 1 at different current densities

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Comparative Example 1 1A/g 1653F/g 1844F/g 1372F/g 1841F/g 1869F/g 2115F/g 1631F/g 1605F/g 50A/g 590F/g 751F/g 494F/g 819F/g 923F/g 949F/g 760F/g 456F/g 100A/g 359F/g 430F/g 294F/g 492F/g 600F/g 626F/g 413F/g 23.9F/g 150A/g 205F/g 255F/g 173F/g 273F/g 389F/g 410F/g 220F/g 1.05F/g

It can be seen from FIG. 5 that the product prepared by the preparation method of the present invention has a high rate energy storage performance compared with the prior art.

It can be seen from the above examples that the electrode material provided by the present invention still has a high specific capacity of ≥173 F/g at a current density of 150 A/g.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications can be made. It should be regarded as the protection scope of the present invention.

Claims (10)

1. a preparation method of electrode material, is characterized in that, comprises the following steps: Mixing the intercalation solution and the layered double metal hydroxide to carry out an intercalation reaction to obtain an electrode material; The intercalation solution is a straight-chain dicarboxylic acid disodium salt solution or a conjugated polycarboxylic acid sodium salt solution. 2. preparation method as claimed in claim 1, is characterized in that, described layered double metal hydroxide is the curd shape that is cross-connected by double metal hydroxide nanosheets; The interlayer spacing of the double metal hydroxide nanosheets in the layered double metal hydroxide is 0.8-0.85 nm; The electrode material is in the shape of a flower ball that is cross-connected by double metal hydroxide nanosheets; The interlayer spacing of the double metal hydroxide nanosheets in the electrode material is 0.7-1.3 nm. 3. The preparation method according to claim 1, wherein the concentration of the straight-chain dicarboxylic acid disodium salt solution or the conjugated polycarboxylic acid sodium salt solution is independently (0.08-0.12) mol/ L. 4. preparation method as claimed in claim 1 or 3 is characterized in that, the solute in described linear dicarboxylic acid disodium salt solution or conjugated polycarboxylic acid sodium salt solution and layered double metal hydroxide The mass ratio of the substances is independently (5-40):1. 5. preparation method as claimed in claim 4 is characterized in that, the straight-chain dicarboxylic acid disodium salt in described straight-chain dicarboxylic acid disodium salt solution is disodium oxalate, disodium succinate, Disodium glutarate, disodium adipate, disodium pimelic acid, disodium suberate, disodium azelaate, disodium sebacate, disodium n-undecanedicarboxylate and n-dodecanedi One or more of disodium carboxylate. 6. The preparation method of claim 4, wherein the conjugated polycarboxylic acid sodium salt in the conjugated polycarboxylic acid sodium salt solution is trisodium 1,3,5-benzenetricarboxylic acid, Tetrasodium 1,2,4,5-benzenetetracarboxylic acid, disodium 1,4-terephthalate, disodium 1,4-naphthalenedicarboxylate, disodium 2,6-naphthalenedicarboxylate, 3,4,9 , One or more of tetrasodium 10-pyrenetetracarboxylic acid and disodium 4,4'-biphenyl dicarboxylate. 7 . The preparation method according to claim 1 , wherein the temperature of the intercalation reaction is 60-100° C., and the time of the intercalation reaction is 12-72 h. 8 . 8. preparation method as claimed in claim 1 is characterized in that, the preparation method of described layered double metal hydroxide, comprises the following steps: Mix the aqueous solution of metal nitrate solution, oxalate and hexamethylenetetramine, carry out precipitation reaction to obtain layered double metal hydroxide; The metal nitrate solution is a divalent metal nitrate solution or a mixed solution of a divalent metal nitrate and a trivalent metal nitrate. 9. preparation method as claimed in claim 8, is characterized in that, when described metal nitrate solution is the mixed solution of divalent metal nitrate and trivalent metal nitrate: The divalent metal in the divalent metal nitrate is Ni ²⁺ , Co ²⁺ , Mn ²⁺ or Zn ²⁺ ; the trivalent metal in the trivalent metal nitrate is Al ³⁺ , Cr ³⁺ or Fe ³⁺ ; When the metal nitrate solution is a divalent metal nitrate solution: The divalent metal in the divalent metal nitrate is two of Ni ²⁺ , Co ²⁺ , Mn ²⁺ and Zn ²⁺ . 10. Application of the electrode material prepared by the preparation method according to any one of claims 1 to 9 as an electrode material in electrochemistry.

Images