Cobweb-like graphene coated beta-FeOOH nano-rod aggregate lithium ion battery negative electrode material preparation method

Abstract

The invention relates to a cobweb-like graphene coated beta-FeOOH nano-rod aggregate lithium ion battery negative electrode material preparation method, which comprises: dispersing graphene oxide in deionized water to obtain a suspension A; adding FeCl3.6H2O and NaNO3 into deionized water, and adding the obtained solution into the suspension A to obtain suspension B; pouring the suspension B intoa homogeneous phase hydrothermal reaction kettle, sealing the reaction kettle, placing the sealed reaction kettle into a homogeneous phase hydrothermal reaction instrument, and carrying out a reactionto obtain a product C; washing the product C respectively with water and alcohol, and dispersing the washed product in water to obtain a product D; and carrying out freeze drying on the product D toobtain the cobweb-like graphene coated beta-FeOOH nano-rod aggregate lithium ion battery negative electrode material. According to the present invention, the performance of beta-FeOOH is improved by compounding the graphene with the special structure, wherein graphene has advantages of good conductivity and large specific surface area, such that the poor conductivity of beta-FeOOH can be effectively solved by coating the beta-FeOOH with the special cobweb-like graphene while the volume expansion can be inhibited to achieve the stable battery structure so as to improve the cycle stability of the battery.

Description

technical field

[0001] The invention belongs to the technical field of electrochemistry, and in particular relates to a method for preparing a lithium-ion battery negative electrode material wrapped in spiderweb graphene-wrapped β-FeOOH nanorod aggregates. technical background

[0002] Transition metal oxides / hydroxides have become a research hotspot in recent years because of their high specific capacity (>1000mAh / g). The hydroxide FeOOH in the transition metal is a very potential lithium ion negative electrode material, and there are many crystal forms: α, β, γ, etc. Among them, the β-FeOOH anions are arranged in a body-centered cubic (bcc) array, and the structure is not as dense as that of α, γ-FeOOH, which is more conducive to the diffusion of Li+. In addition, the capacity of β-FeOOH is higher or even exceeds that of other iron oxides. However, like most oxide electrodes, β-FeOOH has poor conductivity, and the volume expansion is obvious during charge and discharg...

Examples

Embodiment 1

[0018] 1) Disperse commercially available graphene oxide in 25 mL of deionized water to form a solution with a graphene oxide concentration of 1 mg / mL, and then use an ultrasonic generator to form a uniformly dispersed graphene oxide suspension A;

[0019] 2) The analytically pure FeCl 3 ·6H 2 O and NaNO 3 Add it into 25mL deionized water, stir to make it fully dissolve, and then add it to suspension A to form a mixed solution of iron salt and graphene oxide, wherein the concentration of iron salt is 0.05mol / L, and the concentration of sodium salt is 0.05mol / L. 2 / 3 of the salt concentration, and then disperse the mixed solution with an ultrasonic generator to obtain a suspension B;

[0020] 3) Pour the suspension B prepared above into a homogeneous hydrothermal reaction kettle, control the filling degree to 30%, then seal the reaction kettle, and put it into a homogeneous hydrothermal reactor at 50°C for hydrothermal reaction , naturally cooled to room temperature after the...

Embodiment 2

[0027] 1) Disperse commercially available graphene oxide in 30mL deionized water to form a solution with a graphene oxide concentration of 2mg / mL, and then use an ultrasonic generator to form a uniformly dispersed graphene oxide suspension A;

[0028] 2) The analytically pure FeCl 3 ·6H 2 O and NaNO 3 Add it into 20mL deionized water, stir it to fully dissolve, then add it into suspension A, and configure it as a mixed solution of iron salt and graphene oxide, wherein the concentration of iron salt is 0.3mol / L, and the concentration of sodium salt is 0.3mol / L. 2 / 3 of the salt concentration, and then disperse the mixed solution with an ultrasonic generator to obtain a suspension B;

[0029] 3) Pour the suspension B prepared above into a homogeneous hydrothermal reaction kettle, control the filling degree to 80%, then seal the reaction kettle, put it into a homogeneous hydrothermal reactor at 70°C for hydrothermal reaction , naturally cooled to room temperature after the reac...

Embodiment 3

[0033] 1) Disperse commercially available graphene oxide in 35mL deionized water to form a solution with a graphene oxide concentration of 5mg / mL, and then use an ultrasonic generator to form a uniformly dispersed graphene oxide suspension A;

[0034] 2) The analytically pure FeCl 3 ·6H 2 O and NaNO 3 Add it into 15mL deionized water, stir to make it fully dissolve, and then add it to suspension A to form a mixed solution of iron salt and graphene oxide, wherein the concentration of iron salt is 0.5mol / L, and the concentration of sodium salt is 0.5mol / L. 2 / 3 of the salt concentration, and then disperse the mixed solution with an ultrasonic generator to obtain a suspension B;

[0035] 3) Pour the suspension B prepared above into a homogeneous hydrothermal reactor, control the filling degree to 60%, then seal the reactor, put it into a homogeneous hydrothermal reactor at 150°C for hydrothermal reaction , naturally cooled to room temperature after the reaction to obtain produc...

technical field

[0001] The invention belongs to the technical field of electrochemistry, and in particular relates to a method for preparing a lithium-ion battery negative electrode material wrapped in spiderweb graphene-wrapped β-FeOOH nanorod aggregates. technical background

[0002] Transition metal oxides / hydroxides have become a research hotspot in recent years because of their high specific capacity (>1000mAh / g). The hydroxide FeOOH in the transition metal is a very potential lithium ion negative electrode material, and there are many crystal forms: α, β, γ, etc. Among them, the β-FeOOH anions are arranged in a body-centered cubic (bcc) array, and the structure is not as dense as that of α, γ-FeOOH, which is more conducive to the diffusion of Li+. In addition, the capacity of β-FeOOH is higher or even exceeds that of other iron oxides. However, like most oxide electrodes, β-FeOOH has poor conductivity, and the volume expansion is obvious during charge and discharg...

Examples

Embodiment 1

[0018] 1) Disperse commercially available graphene oxide in 25 mL of deionized water to form a solution with a graphene oxide concentration of 1 mg / mL, and then use an ultrasonic generator to form a uniformly dispersed graphene oxide suspension A;

[0019] 2) The analytically pure FeCl 3 ·6H 2 O and NaNO 3 Add it into 25mL deionized water, stir to make it fully dissolve, and then add it to suspension A to form a mixed solution of iron salt and graphene oxide, wherein the concentration of iron salt is 0.05mol / L, and the concentration of sodium salt is 0.05mol / L. 2 / 3 of the salt concentration, and then disperse the mixed solution with an ultrasonic generator to obtain a suspension B;

[0020] 3) Pour the suspension B prepared above into a homogeneous hydrothermal reaction kettle, control the filling degree to 30%, then seal the reaction kettle, and put it into a homogeneous hydrothermal reactor at 50°C for hydrothermal reaction , naturally cooled to room temperature after the...

Embodiment 2

[0027] 1) Disperse commercially available graphene oxide in 30mL deionized water to form a solution with a graphene oxide concentration of 2mg / mL, and then use an ultrasonic generator to form a uniformly dispersed graphene oxide suspension A;

[0028] 2) The analytically pure FeCl 3 ·6H 2 O and NaNO 3 Add it into 20mL deionized water, stir it to fully dissolve, then add it into suspension A, and configure it as a mixed solution of iron salt and graphene oxide, wherein the concentration of iron salt is 0.3mol / L, and the concentration of sodium salt is 0.3mol / L. 2 / 3 of the salt concentration, and then disperse the mixed solution with an ultrasonic generator to obtain a suspension B;

[0029] 3) Pour the suspension B prepared above into a homogeneous hydrothermal reaction kettle, control the filling degree to 80%, then seal the reaction kettle, put it into a homogeneous hydrothermal reactor at 70°C for hydrothermal reaction , naturally cooled to room temperature after the reac...

Embodiment 3

[0033] 1) Disperse commercially available graphene oxide in 35mL deionized water to form a solution with a graphene oxide concentration of 5mg / mL, and then use an ultrasonic generator to form a uniformly dispersed graphene oxide suspension A;

[0034] 2) The analytically pure FeCl 3 ·6H 2 O and NaNO 3 Add it into 15mL deionized water, stir to make it fully dissolve, and then add it to suspension A to form a mixed solution of iron salt and graphene oxide, wherein the concentration of iron salt is 0.5mol / L, and the concentration of sodium salt is 0.5mol / L. 2 / 3 of the salt concentration, and then disperse the mixed solution with an ultrasonic generator to obtain a suspension B;

[0035] 3) Pour the suspension B prepared above into a homogeneous hydrothermal reactor, control the filling degree to 60%, then seal the reactor, put it into a homogeneous hydrothermal reactor at 150°C for hydrothermal reaction , naturally cooled to room temperature after the reaction to obtain produc...

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