CN109994322B - A battery-type supercapacitor and use thereof - Google Patents

Abstract

The invention discloses a battery type super capacitor and application thereof, comprising a positive electrode, a negative electrode, a diaphragm arranged between the positive electrode and the negative electrode and electrolyte or electrolyte, wherein the positive electrode active substance is manganese oxide, the negative electrode active substance is carbon material, and the electrolyte or gel electrolyte contains zinc ions; at least one of the positive electrode and the negative electrode contains zinc ions. The problems of potential mismatching of positive and negative electrodes, large internal resistance, low coulombic efficiency, poor cycle life and the like can be effectively solved, so that the battery type super capacitor which is low in cost, high in working voltage, high in capacity, capable of being charged and discharged rapidly and long in cycle life is obtained.

Description

A battery-type supercapacitor and use thereof

technical field

The invention belongs to the field of electrochemical energy storage devices, relates to a battery-type supercapacitor, in particular to a battery-type supercapacitor and uses thereof.

Background technique

In the field of batteries, the importance of cost and safety performance has become increasingly prominent, so the replacement of mainstream organic electrolytes with aqueous electrolytes has become a research hotspot. At present, although zinc ion-containing solutions have been reported to be used in rechargeable batteries, the cycle life of existing zinc ion batteries is less than 500 times. At the same time, during the cycle process, the negative electrode of the zinc sheet is prone to the formation of dendrites, which will cause the volume expansion of the negative electrode, and at the same time, there is a risk of puncturing the diaphragm and causing a short circuit of the battery.

Supercapacitors are a new type of energy storage device between batteries and traditional electrostatic capacitors. Compared with batteries, supercapacitors have larger specific power (more than 10 times), and have the characteristics of instantaneous release of extra-large current, short charging time, high charging and discharging efficiency, and long cycle life, but their energy density is much lower than that of batteries. Patent document CN 103560019B uses composite metal oxides (energy storage materials formed by doping two or more metals, such as ZnCo ₂ O ₄ , ZnMn ₂ O ₄ , ZnFe ₂ O ₄ ) as positive electrode active materials, zinc and carbon The material constitutes the negative electrode active material, and a zinc ion hybrid supercapacitor is prepared. However, the hybrid supercapacitor has a large voltage drop (>0.4 V), and requires high-temperature calcination to prepare composite metal oxides such as ZnCo ₂ O ₄ , ZnMn ₂ O ₄ , ZnFe ₂ O ₄ as positive active materials, and the process is complicated and expensive. high. At the same time, due to the presence of metallic zinc in the negative electrode, the problem of zinc dendrites during high-power charging and discharging still exists. Patent document CN 107910195 A uses carbon material as positive electrode active material and zinc flakes or zinc foil as negative electrode material to prepare a zinc ion battery type supercapacitor, but the problem of dendrites caused by the negative electrode of zinc flakes and its potential safety hazards still exist.

SUMMARY OF THE INVENTION

In order to improve the above-mentioned technical problems, the present invention provides a battery-type supercapacitor, which includes a positive electrode, a negative electrode, a separator arranged between the positive electrode and the negative electrode, and an electrolyte or a gel electrolyte, wherein the positive electrode active material is manganese oxide, and the negative electrode is The active material is a carbon material, and the electrolyte or gel electrolyte contains zinc ions; and at least one of the positive and negative electrodes contains zinc ions.

According to the present invention, the mass fraction of zinc ions in the positive electrode and/or the negative electrode may be 0.01-30 wt % of the active material in the corresponding electrode, for example, 1-25 wt %, 10-20 wt %; The mass fraction of ions can be 1-20wt% of the positive electrode active material, preferably 10-20wt%, as an example, the mass fraction of zinc ions in the positive electrode can be 1wt%, 5wt%, 10wt%, 15wt% of the positive electrode active material , 20wt%; the mass fraction of zinc ions in the negative electrode can be 5-20wt% of the negative electrode active material, preferably 10-20wt%, as an example, the mass fraction of zinc ions in the negative electrode can be 5wt% of the negative electrode active material , 10wt%, 20wt%. Among them, the purpose of containing zinc ions in the positive electrode and/or the negative electrode is to match the potential between the positive electrode and the negative electrode, so that the working voltage range and capacitance of the battery-type supercapacitor are as large as possible.

The positive electrode and/or the negative electrode contains zinc ions, for example, by electrochemically treating the positive electrode and/or the negative electrode in a zinc salt. As an example, the positive or negative electrode of a battery-type supercapacitor is used as the working electrode, and zinc is used as the counter electrode, the working electrode and the counter electrode are placed in a zinc sulfate solution, and a constant voltage is applied between the working electrode and the counter electrode to make the battery-type supercapacitor The positive or negative electrode of the capacitor contains zinc ions.

According to the present invention, the positive electrode and/or the negative electrode of the battery-type supercapacitor contains zinc ions. Preferably, zinc ions are embedded in the crystal lattice of the positive electrode active material; preferably, the negative electrode (preferably the negative electrode active material) adsorbs zinc ions.

According to the present invention, the manganese oxide can be selected from at least one of MnO ₂ , Mn ₃ O ₄ , Mn ₂ O ₃ and MnO; the crystal form of the manganese oxide is not particularly limited, and can be α, β, Any one of γ, δ and amorphous; wherein, the source of the manganese oxide is not particularly limited. Illustratively, the manganese oxide may be selected from α-MnO ₂ , α-Mn ₂ O ₃ , Mn ₃ O ₄ , MnO or amorphous MnO ₂ .

According to the present invention, the carbon material can be selected from at least one of activated carbon, activated carbon fiber, carbon aerogel, carbon nanotube, mesoporous carbon, graphene, carbide skeleton carbon and nanogate carbon; preferably activated carbon, At least one of carbon aerogel, carbon nanotube and graphene.

According to the present invention, the zinc ions in the electrolyte or in the gel electrolyte are selected from zinc nitrate, zinc sulfate, zinc chloride, zinc trifluoroacetate, zinc methanesulfonate, zinc trifluoromethanesulfonate, ethyl At least one of zinc sulfonate, zinc propylsulfonate, zinc tetrafluoroborate, zinc benzenesulfonate, and zinc perchlorate; preferably selected from zinc sulfate and/or zinc trifluoromethanesulfonate.

The solvent in the electrolyte is selected from at least one of water, organic solvents and ionic liquids; the organic solvent is selected from at least one of esters, sulfones, ethers, nitriles, alkanes and alkenes. The ionic liquid is selected from at least one of imidazole, piperidine, pyrrole, quaternary ammonium and amide ionic liquids. Preferably, the solvent is selected from water or acetonitrile.

Preferably, the concentration of zinc ions in the electrolyte is 0.1-4 mol/L, more preferably 1-2 mol/L, such as 1 mol/L, 1.5 mol/L, 2 mol/L, 3 mol/L, 4 mol/L . Preferably, the electrolyte or gel electrolyte also contains manganese ions, and the manganese ions come from at least one of manganese sulfate, manganese nitrate, manganese acetate, and manganese chloride; the concentration of the manganese ions is 0.01-2 mol /L, preferably 0.1 to 1 mol/L, for example, 0.1 mol/L, 0.2 mol/L, or 0.5 mol/L. As an example, the electrolyte or gel electrolyte may be selected from at least one of an aqueous solution of zinc sulfate, an aqueous solution of zinc trifluoromethanesulfonate, an acetonitrile solution of zinc trifluoromethanesulfonate, and an aqueous solution of manganese sulfate. According to the present invention, the gel electrolyte is a gel state polymer containing zinc ions, and the gel state polymer can be selected from polyvinyl alcohol, polyethylene oxide, agar, gelatin, sodium polyacrylate and xanthan gum At least one, preferably xanthan gum, polyvinyl alcohol or polyethylene oxide. Wherein, the source and concentration of the zinc ions have the meanings as described above. Exemplarily, the gel electrolyte may be selected from a mixture of at least one of xanthan gum, polyvinyl alcohol and polyethylene oxide and zinc sulfate.

According to the present invention, the capacity densities of the positive electrode active material manganese oxide and the negative electrode active material carbon material are different. In order to make the capacity of the positive electrode active material and the negative electrode active material equal, the capacity of the battery-type supercapacitor should be as large as possible. The mass ratio of the active substances may be (2-10):1, preferably (4.5-6):1, as an example, the mass ratio may be 2:1, 3:1, 4:1, 4.5:1, 5 :1, 6:1, 7:1, 8:1, 9:1, 10:1.

According to the present invention, the separator is not particularly limited, and separators known in the art can be used. For example, the separator can be selected from at least one of porous polymer films, inorganic porous films, organic composite films and inorganic composite films; preferably at least one of filter paper, glass fiber separator and polypropylene separator.

According to the present invention, the positive electrode further comprises a conductive agent, a binder and a positive electrode current collector; specifically, the positive electrode is made of a positive electrode active material, a conductive agent and a binder adhered to the positive electrode current collector. Likewise, the negative electrode further includes a conductive agent, a binder and a negative electrode current collector; specifically, the negative electrode is made of a negative electrode active material, a conductive agent and a binder adhered to the negative electrode current collector.

Wherein, the conductive agent, binder, positive electrode current collector and negative electrode current collector are not particularly limited, and products known in the art may be used. For example, the conductive agent can be at least one of conductive carbon black (such as Super P), carbon nanotubes, graphene and Ketjen black; the binder can be polyvinylidene fluoride, polytetrafluoroethylene, At least one of cellulose and styrene-butadiene rubber; the positive electrode current collector and the negative electrode current collector can be at least one of titanium foil, stainless steel foil, titanium mesh, stainless steel mesh and graphite paper.

According to the present invention, the specific capacity of the battery-type supercapacitor is ≥30mAh/g. Exemplarily, the specific capacity of the battery-type supercapacitor is 30mAh/g, 36mAh/g, 40mAh/g, 41mAh/g, 45mAh/g g, 48mAh/g, 50mAh/g, 53mAh/g, 56mAh/g, 60mAh/g. According to the preparation method of the present invention, the number of cycles of charge and discharge of the battery-type supercapacitor is ≥100 times, for example, ≥1000 times, ≥2000 times, and ≥2500 times.

The present invention also provides the use of the battery-type supercapacitor for storing energy, such as storing electrical energy.

Beneficial effects of the present invention:

The battery-type supercapacitor provided by the present invention has both high energy density of secondary battery and high power density of capacitor. The positive electrode and/or the negative electrode of the battery-type supercapacitor contains zinc ions, which can effectively solve the problems of potential mismatch and capacity mismatch between the positive electrode and the negative electrode. In addition, the battery-type supercapacitor has excellent characteristics such as low cost, high working voltage, high capacity, fast charge and discharge, and long cycle life, and the preparation process is simple and low in cost.

Description of drawings

FIG. 1 is a charge-discharge curve diagram of a battery-type supercapacitor according to Example 1 of the present invention.

FIG. 2 is a cyclic voltammetry diagram of the battery-type supercapacitor of Example 1 of the present invention.

FIG. 3 is a cycle performance test graph of the battery-type supercapacitor of Example 1 of the present invention.

Figure 4 shows the surface pictures of the zinc sheet electrode (left) in Comparative Example 1 and the activated carbon electrode (right) in Example 1 before and after 2000 cycles.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the protection scope of the present invention. In addition, it should be understood that after reading the content disclosed in the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the protection scope defined by the present invention.

The experimental methods used in the following examples are conventional methods unless otherwise specified; the reagents, materials, etc. used in the following examples can be obtained from commercial sources unless otherwise specified.

Example 1

Preparation of conventional positive and negative electrodes: α-manganese dioxide, acetylene black, and styrene-butadiene rubber (SBR) were made into electrode slurry in a mass ratio of 80:10:10, coated on titanium foil, and dried as a positive electrode; according to Activated carbon, acetylene black, and SBR were weighed in a mass ratio of 80:10:10 to make an electrode slurry, which was coated on a titanium foil and used as a negative electrode after drying.

Treatment of positive and negative electrodes: take manganese dioxide positive electrode as the working electrode and zinc as the counter electrode, place the working electrode and the counter electrode in a 2mol/L zinc sulfate solution, and apply a constant voltage of 1 V between the working electrode and the counter electrode, Hold for 2 hours; take the active carbon negative electrode as the working electrode, zinc as the counter electrode, and keep the time between the working electrode and the counter electrode at a constant potential of 1 V for 2 hours.

Assembly of battery-type supercapacitor: The treated positive electrode, separator, and treated negative electrode are stacked in the casing in turn, and the aqueous solution of 2mol/L zinc sulfate and 0.1mol/L manganese sulfate is added to assemble the battery-type supercapacitor.

Examples 2 to 10: The preparation method is the same as that of Example 1, except that the positive zinc ions in the battery-type supercapacitor account for the mass fraction of the electrode active material (referred to as the zinc ion content of the positive electrode), and the negative zinc ions account for the mass fraction of the electrode active material. (referred to as the zinc ion content of the negative electrode), the positive electrode active material, the negative electrode active material, the mass ratio of the negative electrode to the positive electrode active material (referred to as negative electrode/positive electrode), and the electrolyte composition are different, as shown in Table 1.

Table 1.

Example 13: Different from Example 1, xanthan gum and zinc sulfate were dissolved in water to prepare a xanthan gum-zinc sulfate gel electrolyte. In the button shell, an all-solid-state battery-type supercapacitor is made.

Examples 14 to 15: The difference from Example 13 is that the positive electrode zinc ions in the battery-type supercapacitor account for the mass fraction of the electrode active material (referred to as the zinc ion content of the positive electrode), and the negative electrode zinc ions account for the mass fraction of the electrode active material (referred to as the mass fraction of the electrode active material). The zinc ion content of the negative electrode), the positive electrode active material, the negative electrode active material, the mass ratio of the negative electrode to the positive electrode active material (referred to as negative electrode/positive electrode), and the gel electrolyte composition are different, as shown in Table 2.

Table 2.

Comparative Example 1

Preparation of conventional positive and negative electrodes: α-manganese dioxide, acetylene black, and SBR were made into electrode slurry according to the mass ratio of 80:10:10, coated on titanium foil, and dried as the positive electrode; the metal zinc sheet was used as the negative electrode .

Assembly of the zinc ion battery: The positive electrode, the separator and the negative electrode sheet are stacked in the casing in turn, and the aqueous solution of 2 mol/L zinc sulfate and 0.1 mol/L manganese sulfate is added to make a zinc ion battery.

Comparative Example 2

Preparation of conventional positive and negative electrodes: α-manganese dioxide, acetylene black, and SBR were made into electrode slurry in a mass ratio of 80:10:10, coated on titanium foil, and dried as a positive electrode; activated carbon, acetylene black, SBR is made into electrode slurry according to the mass ratio of 80:10:10, which is coated on titanium foil and used as a negative electrode after drying. The mass ratio of negative electrode and positive electrode is 1:1.

Assembly of the supercapacitor: stack the positive electrode sheet, the separator and the negative electrode sheet in turn, put them in the button shell, and add 2mol/L zinc sulfate and 0.1mol/L manganese sulfate aqueous solution to make a conventional supercapacitor.

The products prepared in Examples 1 to 15 and Comparative Examples 1 to 2 were tested at room temperature by the Land battery tester of Wuhan Blue Electric Company, with constant current charge-discharge method and cyclic voltammetry, and the voltage range was 0 to 1.6V. . Specifically, the constant current charge-discharge curve test was carried out at a current density of 0.5 A/g and a voltage range of 0 to 1.6 V: a cyclic voltammetry curve test was carried out at a scan rate of 2mV/s and a voltage range of 0 to 1.6 V; at 0.5 A /g current density, cycle performance test was carried out in the voltage range of 0 to 1.6 V.

The performance results of the battery-type supercapacitors of Examples 1-15 and the batteries or supercapacitors of Comparative Examples 1-2 are shown in Table 3.

Table 3 Specific capacities of devices of Examples 1-15 and Comparative Examples 1-2

From the curves in Figures 1 and 2, it is calculated that the discharge specific capacity of the battery-type supercapacitor prepared in Example 1 is as high as 40mAh/g. It can be seen from Figure 3 that it has a stable charge-discharge curve and excellent cycle stability, and the cycle is 2500 times. , the capacity is almost not lost, indicating that the battery-type supercapacitor prepared in Example 1 has excellent electrochemical performance. As shown in Figure 4, after 2000 charge-discharge cycles of the zinc-ion battery prepared in Comparative Example 1, sharp and convex dendrites were formed on the surface of the zinc sheet (the left picture), posing a potential safety hazard; the battery-type supercapacitor prepared in Example 1 After 2000 charge-discharge cycles, the activated carbon anode did not change significantly before and after charge-discharge (right picture), which improved the safety of dendrites well.

It can be seen from Table 3 that the specific capacity of the battery-type supercapacitors prepared in Examples 1 to 15 is that the discharge specific capacity is as high as 30 to 53 mAh/g, far exceeding the conventional supercapacitors of Comparative Example 2. The zinc ions of the negative electrode and the negative electrode account for 10-20% of the mass fraction of the electrode active material. When the ratio of the negative electrode and the positive electrode active material is (4.5-6):1, the prepared battery-type supercapacitor has the highest specific capacity.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (14)

1. A battery type super capacitor is characterized by comprising a positive electrode, a negative electrode, a diaphragm arranged between the positive electrode and the negative electrode and an electrolyte or gel electrolyte, wherein the active substance of the positive electrode is manganese oxide, the active substance of the negative electrode is a carbon material, and the electrolyte or gel electrolyte contains zinc ions; at least one of the positive electrode and the negative electrode contains zinc ions;

the positive electrode and/or the negative electrode is/are subjected to electrochemical treatment in zinc salt to enable the positive electrode and/or the negative electrode to contain zinc ions;

the mass fraction of zinc ions in the positive electrode and/or the negative electrode in the corresponding electrode active substance is 0.01-30 wt%;

the mass ratio of the negative electrode active material to the positive electrode active material is (2-10) to 1;

the molar concentration of zinc ions contained in the electrolyte or gel electrolyte is 0.1-4 mol/L.

2. The battery-type supercapacitor according to claim 1, wherein the zinc ions in the positive electrode and/or the negative electrode account for 10 to 20 wt% of the mass fraction of the corresponding electrode active material.

3. The battery-type supercapacitor according to claim 1, wherein the mass ratio of the negative electrode active material to the positive electrode active material is (4.5-6): 1.

4. The battery-type supercapacitor according to claim 1, wherein the manganese oxide is selected from MnO₂、Mn₃O₄、Mn₂O₃And MnO.

5. The battery-type supercapacitor according to claim 4, wherein the manganese oxide has a crystalline form of at least one of α, β, γ, and amorphous.

6. The battery-type supercapacitor according to any one of claims 1 to 5, wherein the carbon material is at least one selected from activated carbon, carbon aerogel, carbon nanotube, mesoporous carbon, graphene, carbide-skeletal carbon, and nanomesh carbon.

7. The battery-type supercapacitor according to claim 6, wherein the carbon material is selected from activated carbon fibers.

8. The battery-type supercapacitor according to claim 6, wherein the zinc ions in the electrolyte or gel electrolyte are derived from at least one of zinc nitrate, zinc sulfate, zinc chloride, zinc trifluoroacetate, zinc methanesulfonate, zinc trifluoromethanesulfonate, zinc ethylsulfonate, zinc propylsulfonate, zinc tetrafluoroborate, zinc benzenesulfonate, zinc perchlorate.

9. The battery-type supercapacitor according to claim 1 or 8, wherein the electrolyte or gel electrolyte contains zinc ions at a molar concentration of 1 to 2 mol/L.

10. The battery-type supercapacitor according to claim 8, wherein the solvent in the electrolyte is selected from at least one of water, an organic solvent, and an ionic liquid;

the organic solvent is selected from at least one of ester, sulfone, ether, nitrile, alkane and olefin organic solvents;

the ionic liquid is at least one selected from imidazole, piperidine, pyrrole, quaternary ammonium and amide ionic liquids.

11. The battery-type supercapacitor according to claim 8, wherein the gel electrolyte is a gel-state polymer containing zinc ions; the polymer is selected from at least one of polyvinyl alcohol, polyethylene oxide, agar, gelatin, sodium polyacrylate and xanthan gum.

12. The battery-type supercapacitor according to claim 8, wherein the electrolyte or gel electrolyte further contains manganese ions from at least one of manganese sulfate, manganese nitrate, manganese acetate, and manganese chloride.

13. The battery-type supercapacitor according to claim 12, wherein the molar concentration of the manganese ions is 0.01 to 2 mol/L.

14. Use of a battery-type supercapacitor according to any one of claims 1 to 13 for storing energy.

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