WO2018072457A1

WO2018072457A1 - Method for preparing multi-ion embedded supercapacitor with electrochemical alkaline activation

Info

Publication number: WO2018072457A1
Application number: PCT/CN2017/087852
Authority: WO
Inventors: 邵明飞; 栗振华; 卫敏; 段雪
Original assignee: 北京化工大学
Priority date: 2016-10-21
Filing date: 2017-06-11
Publication date: 2018-04-26
Also published as: CN106409532B; CN106409532A

Abstract

A method for preparing a multi-ion embedded supercapacitor with electrochemical alkaline activation. A simple and rapid electrochemical alkaline activation method is employed to perform activation or deactivation processing on a transition metal hydroxide containing cobalt or nickel to realize intelligent regulation and control of the hydroxide electrode materials to storage capacity of various metal cations, and is applied to an ion embedded supercapacitor. Provided is a universal method capable of improving storage capacity of electrode materials of an ion embedded supercapacitor, and the range of application of the transition metal hydroxide electrode materials is further widened in the field of energy storage.

Description

Method for preparing multi-ion embedded supercapacitor by electrochemical alkali activation method

Technical field

The invention belongs to the field of synthesis of inorganic nano materials, and particularly relates to a more universal method for preparing multi-ion embedded supercapacitors by electrochemical alkali activation method.

Background technique

With the continuous advancement of science and technology and the continuous improvement of human living standards, people's demand for material life has not only been limited to solving the problem of food and clothing, but to pursue a more convenient, more efficient and more colorful life. Nowadays, various electric drive devices are enriching people's horizons. However, these devices, from electric cranes to electric cars to mobile phones, laptops, mp3s, etc., all face the same problem, that is, they need more efficient storage. Energy and energy supply equipment. Along with the development of battery technology in recent years, especially the wide application of lithium-ion batteries, the capacity of batteries is getting higher and higher, and the time for electronic products to charge for a single charge is longer and longer. However, in the field of electronic products requiring large instantaneous currents such as electric vehicles, household electrical appliances, and aerospace facilities, conventional batteries face bottlenecks in use due to low power density. At the same time, although the conventional capacitor has a fast charge and discharge rate and a long cycle life, it has many disadvantages. For example, the capacity density is too low, the self-discharge phenomenon is serious, and the working voltage is low, which greatly limits its practicability. Therefore, it is one of the most concerned topics for scientists in the energy field worldwide to seek new energy devices with high specific capacity, high specific power, long cycle life, and low cost and cleanliness.

In order to enable energy storage equipment to have both high power density and energy density, as well as good cycle stability, researchers have proposed the concept of supercapacitors. It combines the advantages of traditional batteries and traditional capacitors. It has the characteristics of short charging time, long service life, good temperature characteristics, energy saving and environmental protection. It is expected to become an emerging high-efficiency energy storage device. Supercapacitors can be divided into electric double layer capacitors and tantalum capacitors from the energy storage mechanism. The supercapacitor electrode materials currently studied are mainly concentrated on carbon materials, conductive polymers, and inorganic metal oxides/hydroxides. Although supercapacitors have many attractive advantages, their further development and practicality still face enormous challenges. This is mainly focused on: First, the electrode material is difficult to meet the requirements of high energy density, rapid charge and discharge and long service life in practical applications. Although some progress has been made in the research of supercapacitor materials through material recombination or micro/nano structure regulation, it is still challenging to find high-efficiency and low-cost supercapacitor electrode materials. Second, alkaline electrolytes are the main The class capacitors still face the disadvantage of low storage potential window, which restricts the practical process of supercapacitors.

In order to solve these problems, researchers have proposed the concept of ion-embedded supercapacitors based on the original supercapacitors. It differs from electric double layer capacitors and tantalum capacitors in that it relies mainly on the rapid insertion/desorption of metal cations on the surface or inside of the electrode material to store and release the charge. In this process, since the metal cation does not undergo redox reaction with the electrode material during the insertion/extraction, it has a higher power density than the conventional metal ion battery, and a faster charge and discharge can be realized. In addition, the electrolyte used in the ion-embedded supercapacitor is mainly a neutral metal salt electrolyte, so it has a higher energy storage potential window than the conventional supercapacitor. At present, the research on ion-embedded supercapacitor electrode materials mainly focuses on metal carbide (MC _X ), metal sulfide (MS _X ) and metal oxide (MO _X ), of which MXene is a new type with good electrical conductivity. Layered metal carbides attract the attention of researchers and have become the main force in the development of electrode materials for ion-embedded supercapacitors. Although researchers have made great progress in the research of ion-embedded supercapacitor electrode materials, they still face many problems, such as: First, the electrode material has low ability to store metal ions, poor conductivity, and preparation cost. Higher, these need to further develop new electrode materials with better performance suitable for rapid insertion/extraction of cations; 2. Most electrode materials have better embedding/extraction properties only for Li ⁺ , and for other metal cations (Na ⁺ , K ⁺ , Ca ²⁺ , Mg ²⁺ , Zn ²⁺ , Al ³⁺ ) have no storage performance or poor performance. However, considering the content of the earth's crust, the content of Li ⁺ in the earth's crust is the lowest relative to other metal cations. Therefore, it is extremely urgent to develop electrode materials suitable for the embedding/extraction of other metal cations.

Summary of the invention

The invention aims at the shortcomings of the current ion-intercalating electrode material in the low capacity of storing metal ions, poor conductivity, high preparation cost, etc., and proposes a metal hydroxide (MOH _X ) as a novel ion-embedded supercapacitor electrode material through simple An electrochemical alkali activation method is used to improve the metal ion storage performance of the electrode material. The specific operation steps of the invention for preparing a multi-ion embedded supercapacitor based on a simple and rapid electrochemical alkali activation method are as follows:

1). Using a metal hydroxide nanomaterial containing cobalt or nickel as a positive electrode, 20–50 mL of an alkaline solution having a concentration of 1–5 g/L as an electrolyte, by cyclic voltammetry, scanning at 1–100 mV s ^-1 At a rate, at a potential window of 0–0.1V to 0–0.8V, cycle scan 1–50 times for activation;

2). Step 1) Activated cobalt or nickel-containing metal hydroxide nanomaterial as positive electrode, 20–50 mL of alkaline solution with a concentration of 1–5 g/L as electrolyte, by cyclic voltammetry, at 1 At a scan rate of –100mV s ^-1 , cyclically scan 1–50 times at a potential window of 0–(-0.1V) to 0–(-1.5V) for deactivation;

3). The activated cobalt or nickel-containing metal hydroxide of step 1) or the deactivated cobalt or nickel-containing metal hydroxide of step 2) is used as a positive electrode, and 1–5 g/L The nitrate or sulfate electrolyte solution constitutes a multi-ion embedded supercapacitor for ion storage performance testing.

The alkaline solution as the electrolyte described in the step 1) or 2) is one or more of KOH, NaOH, and LiOH.

The cobalt-containing hydroxide used in the step 1) is one or more of Co(OH) ₂ , CoNi-LDH, CoFe-LDH, CoAl-LDH, CoMn-LDH, and CoV-LDH.

The nickel-containing hydroxide used in the step 1) is one or more of Ni(OH) ₂ , NiFe-LDH, NiAl-LDH, NiMn-LDH, and NiV-LDH.

The metal nitrate electrolyte used in the step 3) is: LiNO ₃ , NaNO ₃ , KNO ₃ , Ca(NO ₃ ) ₂ , Mg(NO ₃ ) ₂ or Zn(NO ₃ ) ₂ .

The metal sulfate electrolyte used in the step 3) is: Li ₂ SO ₄ , Na ₂ SO ₄ , K ₂ SO ₄ , CaSO ₄ , MgSO ₄ or ZnSO ₄ .

The invention has the advantages that the activation or deactivation treatment of the cobalt or nickel-containing hydroxide by a simple and rapid electrochemical alkali activation method realizes the storage capacity of the hydroxide electrode material for various metal cations. Intelligent regulation can be effectively applied to ion-embedded supercapacitors; it provides a new and more versatile method to greatly improve the energy storage performance of ion-embedded supercapacitor electrode materials; further broaden the transition metal hydroxide electrode The range of applications of materials in the field of energy storage.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a diagram showing the mechanism of electrochemical alkali activation and deactivation of a metal hydroxide in Example 1, and metal ion cation insertion and removal.

Figure 2 is a cyclic voltammetry curve for the storage of different metal cations of cobalt iron hydrotalcite before and after electrochemical alkali activation treatment (represented by AA and BA, respectively) in Example 1.

Figure 3 is a graph showing the charge and discharge curves of cobalt iron hydrotalcite for storage of different metal cations before and after electrochemical alkali activation treatment (represented by AA and BA, respectively) in Example 1.

Figure 4 is an intelligently controlled cyclic voltammetry curve for lithium ion storage capacity of cobalt iron hydrotalcite treated by electrochemical alkali activation (denoted by AA) and deactivated (represented by DA) in Example 1.

Fig. 5 is a graph showing the stability of the cobalt-iron hydrotalcite after the electrochemical alkali activation treatment in Example 1 after 10,000 consecutive charge and discharge tests.

detailed description

Example 1

1). Activate the treatment of cobalt iron hydrotalcite:

a: preparing 50 ml of a KOH solution having a concentration of 5 g/L as an electrolyte;

b: using a cobalt-iron hydrotalcite nano-array as a positive electrode, by cyclic voltammetry, at a scanning rate of 100 mV s ^-1 , under a potential window of 0-0.6 V, cyclically scanning 5 times for activation treatment;

2). Deactivate the cobalt-iron hydrotalcite:

b: using the activated cobalt-hydrotalcite nano-array of step 1) as a positive electrode, by cyclic voltammetry, at a scanning rate of 100 mV s ^-1 , under a potential window of 0 - (-0.6 V), cyclic scanning 5 Deactivation treatment;

3). Study on electrochemical energy storage performance of neutral electrolyte solution

The cobalt iron hydrotalcite subjected to the activation treatment or deactivation treatment in step 1) or 2) is used as a positive electrode at a concentration of 5 g/L of nitrate (LiNO ₃ , NaNO ₃ , KNO ₃ , Ca(NO ₃ ) ₂ , Mg(NO). ₃ ) ₂ , Zn(NO ₃ ) ₂ ) or sulfate (Li ₂ SO ₄ , Na ₂ SO ₄ , K ₂ SO ₄ , CaSO ₄ , MgSO ₄ , ZnSO ₄ ) electrolyte solution for ion storage performance test.

Example 2

1). Activate the treatment of cobalt aluminum hydrotalcite:

a: preparing 50 ml of a 4 g/L NaOH solution as an electrolyte;

b: using a cobalt-aluminum hydrotalcite nano-array as a positive electrode, by cyclic voltammetry, at a scanning rate of 100 mV s ^-1 , under a potential window of 0-0.5 V, cyclically scanning 10 times for activation treatment;

2). Deactivate the cobalt-iron hydrotalcite:

a: preparing 50 ml of a 4 g/L NaOH solution as an electrolyte;

b: using the activated cobalt-hydrotalcite nanocrystal array of step 1) as a positive electrode, cyclically scanning 10 by a cyclic voltammetry at a scanning rate of 50 mV s ^-1 at a potential window of 0 - (-0.5 V) Deactivation treatment;

Step 1) or 2) Activated or deactivated cobalt aluminum hydrotalcite as the positive electrode, respectively at 5g / L of nitrate (LiNO ₃ , NaNO ₃ , KNO ₃ , Ca (NO ₃ ) ₂ , Mg ( The ion storage performance test was carried out in an electrolyte solution of NO ₃ ) ₂ , Zn(NO ₃ ) ₂ ) or sulfate (Li ₂ SO ₄ , Na ₂ SO ₄ , K ₂ SO ₄ , CaSO ₄ , MgSO ₄ , ZnSO ₄ ).

Example 3

1). Activate the treatment of cobalt hydroxide:

a: preparing 50 ml of a LiOH solution having a concentration of 6 g/L as an electrolyte;

b: using a cobalt hydroxide nano-array as a positive electrode, by cyclic voltammetry, at a scanning rate of 100 mV s ^-1 , under a potential window of 0 - 0.1 V, cyclic scanning 20 times, for activation treatment;

2). Deactivate the cobalt hydroxide:

b: using the activated cobalt oxide nano-array of step 1) as a positive electrode, cyclically scanning 10 by cyclic voltammetry at a scanning rate of 100 mV s ^-1 under a potential window of 0 - (-0.1 V) Deactivation treatment;

The step 1) or 2) activated or deactivated cobalt hydroxide is used as the positive electrode at 5 g/L of nitrate (LiNO ₃ , NaNO ₃ , KNO ₃ , Ca(NO ₃ ) ₂ , Mg(NO). ₃ ) ₂ , Zn(NO ₃ ) ₂ ) or sulfate (Li ₂ SO ₄ , Na ₂ SO ₄ , K ₂ SO ₄ , CaSO ₄ , MgSO ₄ , ZnSO ₄ ) electrolyte solution for ion storage performance test.

Example 4

1). Activate the treatment of nickel hydroxide:

b: using a nickel hydroxide nano-array as a positive electrode, by cyclic voltammetry, at a scanning rate of 1-100 mV s ^-1 , under a potential window of 0-0.1 V, cyclically scanning 5 times for activation treatment;

2). Deactivate the nickel hydroxide:

b: using the activated nickel hydroxide nano-array of step 1) as a positive electrode, by cyclic voltammetry, at a scanning rate of 100 mV s ^-1 , under a potential window of 0 - (-0.1 V), cyclic scanning 5 Deactivation treatment;

Step 1) or 2) Activated or deactivated nickel hydroxide is used as the positive electrode at 5 g/L of nitrate (LiNO ₃ , NaNO ₃ , KNO ₃ , Ca(NO ₃ ) ₂ , Mg ( The ion storage performance test was carried out in an electrolyte solution of NO ₃ ) ₂ , Zn(NO ₃ ) ₂ ) or sulfate (Li ₂ SO ₄ , Na ₂ SO ₄ , K ₂ SO ₄ , CaSO ₄ , MgSO ₄ , ZnSO ₄ ).

Claims

A method for preparing a multi-ion embedded supercapacitor by electrochemical alkali activation method, characterized in that the specific operation steps are as follows:

1). Using a metal hydroxide nanomaterial containing cobalt or nickel as a positive electrode, 20–50 mL of an alkaline solution having a concentration of 1–5 g/L as an electrolyte, by cyclic voltammetry, scanning at 1–100 mV s -1 At a rate, at a potential window of 0–0.1V to 0–0.8V, cycle scan 1–50 times for activation;

2). Step 1) Activated cobalt or nickel-containing metal hydroxide nanomaterial as positive electrode, 20–50 mL of alkaline solution with a concentration of 1–5 g/L as electrolyte, by cyclic voltammetry, at 1 At a scan rate of –100mV s -1 , cyclically scan 1–50 times at a potential window of 0–(-0.1V) to 0–(-1.5V) for deactivation;

3). The activated cobalt or nickel-containing metal hydroxide of step 1) or the deactivated cobalt or nickel-containing metal hydroxide of step 2) is used as a positive electrode, and 1–5 g/L The nitrate or sulfate electrolyte solution constitutes a multi-ion embedded supercapacitor for ion storage performance testing.
The method according to claim 1, wherein the alkaline solution as the electrolyte described in the step 1) or 2) is one or more of KOH, NaOH, and LiOH.
The method according to claim 1, wherein the cobalt-containing hydroxide used in the step 1) is: Co(OH) 2 , CoNi-LDH, CoFe-LDH, CoAl-LDH, CoMn-LDH, CoV-LDH. One or several of them.
The method according to claim 1, wherein the nickel-containing hydroxide used in the step 1) is one of Ni(OH) 2 , NiFe-LDH, NiAl-LDH, NiMn-LDH, and NiV-LDH. Or several.
The method for preparing an electrode material according to claim 1, wherein the metal nitrate electrolyte used in the step 3) is: LiNO 3 , NaNO 3 , KNO 3 , Ca(NO 3 ) 2 , Mg(NO 3 ) 2 Or Zn(NO 3 ) 2 .
The method of preparing an electrode material according to claim 1, wherein the metal sulfate electrolyte used in the step 3) is: Li 2 SO 4 , Na 2 SO 4 , K 2 SO 4 , CaSO 4 , MgSO 4 or ZnSO. 4 .