CN106558693B - A kind of aluminum ion battery based on positive electrode containing iodine and preparation method thereof - Google Patents

Abstract

The invention discloses an aluminum ion battery based on an iodine-containing positive electrode and a preparation method thereof. The battery comprises a positive electrode, a negative electrode, an ionic liquid-based electrolyte, and a separator. The liquid-based electrolyte is a mixture of anhydrous aluminum chloride and 1‑ethyl‑3‑methylimidazolium chloride. The reversible chemical reaction can occur in the aluminum ion battery, which is essentially different from the aluminum ion battery that uses aluminum ions to reversibly intercalate and deintercalate between the positive electrode material layers. The positive electrode material used in the battery is simple and easy to obtain, and only conventional equipment is required. Implementation makes the aluminum ion battery widely used in various energy devices.

Description

A kind of aluminum ion battery based on positive electrode containing iodine and preparation method thereof

technical field

The invention belongs to the field of secondary batteries and their preparation, and relates to the preparation technology of aluminum ion batteries, in particular to an aluminum ion battery based on an iodine-containing positive electrode and a preparation method thereof. The battery is based on a reversible chemical reaction between aluminum ions and positive active materials secondary ion battery.

Background technique

As human beings become more and more dependent on various energy-driven devices, the rapid reduction of fossil fuels and increasingly severe environmental problems, people pay more and more attention to the development of energy storage and conversion systems, and most people focus on lithium-ion batteries. Although lithium batteries have been used in large-scale commercial applications for a long time, the energy density and power density of lithium-ion batteries still need to be improved. At present, they are developing into power batteries for electric vehicles. However, the limitation of lithium resources hinders the development of lithium-ion batteries. With its large-scale application, safety issues limit the further development of lithium-ion batteries. Since the end of August 2016, Samsung Note7 has experienced nearly 40 explosion accidents around the world. The new rechargeable battery system has great practical significance.

Compared with lithium, aluminum is the most abundant metal element in the earth's crust, with low cost and low price. In the electrochemical charge-discharge reaction, the number of transferred electrons is 3. Compared with single-electron lithium ions, the theory of aluminum The specific capacity is 2980mAh/g, which ranks the second among all metal elements, second only to lithium (3870mAh/g), and its volume specific capacity is 8050mAh/cm ³ , which is the highest among all metal electrode materials at present. Battery anode materials have incomparable advantages over other metal anode materials.

On April 6, 2015, Nature published the paper "Anultrafast rechargeable aluminum-ion battery" by Dai Hongjie's team at Stanford University. 2V, excellent cycle performance, up to 7500 cycles, the battery has the characteristics of fast charge and discharge and long cycle life. However, its actual specific capacity is low, only 70mAh/g, and the preparation process of graphene foam is relatively cumbersome , the general laboratory can't satisfy it, and it's more difficult to industrialize it.

Chinese patent CN104701541A discloses an aluminum ion battery with WS ₂ as the positive electrode and its preparation method. The WS ₂ layered structure positive electrode material used in the battery shows stable cycle performance, wide electrochemical window, and wide operating temperature range of the battery. But its discharge specific capacity is too low, and the initial discharge specific capacity is the highest specific capacity in the cycle process, and it is only 20mAh/g.

Chinese patent CN105449271A discloses an aluminum ion secondary battery with CuS as the positive electrode and its preparation process. CuS is easy to synthesize, low in cost, non-toxic and harmless. Using CuS material, its first discharge specific capacity is as high as 275mAh/g, and the discharge platform is as high as 1.5 V, but the capacity of the entire battery system decays seriously. After 16 cycles, the capacity decay is 160mAh/g, and the capacity retention rate is only 57%.

For the research on positive electrode materials of room temperature aluminum secondary batteries, most of them are based on the research of materials with layered structure. The layered structure makes the reversible intercalation and extraction of aluminum ions between layers. However, due to the intercalation/extraction of multivalent aluminum ions When the kinetics are poor, making reversible charge and discharge becomes more difficult. Therefore, the development of aluminum-ion batteries based on reversible chemical reactions is of great significance for the commercial application of aluminum-ion batteries.

Contents of the invention

The object of the present invention is to address the deficiencies in the prior art and provide an aluminum ion battery based on an iodine-containing positive electrode and a preparation method thereof. Capacitive charge and discharge, the preparation process of the positive electrode material is simple, only conventional equipment can be implemented, and the raw materials used are cheap and easy to obtain.

Technical solution: In order to achieve the above object, the present invention provides the following technical solutions:

An aluminum ion battery based on an iodine-containing positive electrode, comprising a positive electrode, a negative electrode, an ionic liquid-based electrolyte, and a diaphragm, wherein the positive electrode is polyvinylpyrrolidone iodine or iodoform, the negative electrode is high-purity aluminum foil, and the ionic liquid-based electrolyte It is made by mixing anhydrous aluminum chloride and 1-ethyl-3-methylimidazolium chloride.

In the above technical solution, the molar ratio of anhydrous aluminum chloride and 1-ethyl-3-methylimidazolium chloride in the ionic liquid-based electrolyte is 1:1-10:1.

The active material in the positive electrode contains iodine, and the positive electrode is prepared by a loading method.

The positive electrode obtained by the rolling method, the iodine-containing raw material used is one of polyvinylpyrrolidone iodine (PVPI), iodoform (CHI ₃ ), polyN-vinylcarbazole, prepared by the loading method The iodine-containing raw materials used in the positive electrode are various iodophors.

The iodophors are one or more of polyvinylpyrrolidone iodine, polyethylene glycol iodine, nonylphenol polyoxyethylene ether iodine, polyalcohol ether iodine, and chlorhexidine iodine.

The above-mentioned polyvinylpyrrolidone iodine (PVPI) is brownish red or yellowish brown powder, wherein the iodine content is 9%-12%, preferably, the iodine content is 10%.

The positive electrode material is prepared by a loading method, which specifically includes the following steps:

(1) Weigh positive electrode active material, conductive material, binder respectively; Described positive electrode active material is a kind of in polyvinylpyrrolidone iodine (PVPI), iodoform (CHI ₃ ), polyN-vinylcarbazole The conductive material is one or more of super-P, acetylene black, and Litchen black, and the binder is polytetrafluoroethylene (PTFE) or a polymer derivative with carboxyl groups. The polymer derivatives with carboxyl groups are sodium carboxymethylcellulose (CMC), polyvinylidene fluoride (PVDF) or styrene-butadiene rubber (SBR);

(2) Mix the positive electrode active material and conductive material evenly by grinding or ball milling;

(3) On the basis of step (2), add the binder weighed, grind repeatedly, make the three fully mix uniformly, obtain sheet material;

(4) The sheet material obtained in step (3) is pressed into sheets with a noodle press to make pole pieces;

(5) The above-mentioned pole piece is used as a positive electrode material for assembly into an aluminum ion battery.

In the above solution, in terms of weight ratio, the amount of positive electrode active material is 50-80 parts, the amount of conductive material is 10-20 parts, and the amount of binder is 10-25 parts.

In the above-mentioned aluminum ion battery, a waterproof carbon paper is also provided between the diaphragm and the positive electrode material, and the thickness is between 0.1-0.3mm.

The separator is made of glass fiber material with ion permeability, no reaction with positive and negative electrodes, and good electrochemical stability.

The negative electrode aluminum foil needs to be polished with sandpaper to remove the passivation layer on the surface and make the surface smooth.

The positive electrode material is prepared by a loading method, comprising the following preparation steps:

(1) Prepare iodophor of target concentration and target species.

(2) Weigh the mass of the carbon cloth, and soak the carbon cloth with the above-mentioned iodophor for 0.5h-48h.

(3) Dry the soaked carbon cloth or drain it with the transition compartment of the glove box and weigh it again to obtain the positive electrode material. The prepared positive electrode material, negative electrode aluminum foil, ionic liquid-based electrolyte, diaphragm material, battery case, etc. are assembled into an aluminum ion battery.

Beneficial effects of the present invention: the present invention uses iodine-containing substances as the positive electrode material, high-purity aluminum foil as the negative electrode, and ionic liquid as the electrolyte, forming an aluminum ion battery based on a reversible chemical reaction, and using aluminum ions in the positive electrode material layer There is an essential difference between reversible intercalation and extraction of aluminum ion batteries. The positive electrode material used in the battery is simple and easy to obtain, and can be implemented with only conventional equipment, and the battery performance is excellent, especially the polyvinylpyrrolidone iodine (PVPI) positive electrode material is in The continuous charge and discharge test shows a high specific capacity, the first discharge capacity is close to one-third of the theoretical capacity, and, with the completion of the cycle and the completion of the activation process, the discharge specific capacity increases, see Figure 2 , by adjusting the voltage range for activation, the discharge specific capacity can reach up to 194.8mAh/g, and the coulombic efficiency can be maintained at about 75%, see Figure 3. Therefore, the aluminum ion battery based on the reversible chemical reaction designed in the present invention can be used in various energy devices in the future development.

Description of drawings

Fig. 1 is the cyclic voltammetry curve of the aluminum ion battery prepared in embodiment 1;

Fig. 2 is the 4th, 9th, 14th cycle charge and discharge test curves of the aluminum ion battery prepared in embodiment 2;

Fig. 3 is the cycle performance curve of the aluminum ion battery prepared in Example 3.

Detailed ways

The present invention will be described in more detail below in conjunction with the examples. It should be understood that the specific examples described here are only for explaining the present invention, and the protection scope of the present invention is not limited by these examples.

Example 1

The positive active material is PVPI, the conductive material is Liqin black, and the binder is polytetrafluoroethylene (PTFE). First weigh 0.5g of PVPI and 0.2g of conductive material into the ball mill jar, and put the ball mill jar into a high-performance ball mill , ball milled at 600r/min for 2 hours, put the ball-milled mixture into the mortar, weigh 0.25g of polytetrafluoroethylene (PTFE), and grind it. Form the block into a whole, cut it from the middle with scissors, place the two parts on the noodle press for sheeting, then put them on a glass plate, and roll them with a glass rod until the thickness is about About 0.1mm, use scissors to cut it into pieces of appropriate size, and use it as the positive electrode material of the battery. The negative electrode is made of high-purity aluminum foil with a thickness of 0.03 mm. After being sliced with a punch with a diameter of 13 mm, it is used as the negative electrode material after being polished with fine sandpaper. The ionic liquid-based electrolyte is prepared by mixing anhydrous aluminum chloride and 1-ethyl-3-methylimidazolium chloride at a molar ratio of 1.5:1. A glass fiber filter paper (GF/D, Whatman) was used as the separator. After preparing the required materials, assemble the battery in the glove box. After standing still for half an hour, use the 1470E electrochemical workstation to perform cyclic voltammetry (CV). The scanning voltage range is 0.5-1.25V, and the scanning rate is 0.1 mV/s, through the cyclic voltammetry test, it is determined that the charge and discharge voltage range of the electrode material is 0.6-1.1V, see Figure 1.

Example 2

The positive electrode active material is PVPI, the conductive material is Super-P, and the binder is polytetrafluoroethylene (PTFE). First, weigh 0.5g of PVPI and 0.2g of conductive material Super-P, add them to the ball mill jar, and put the ball mill jar into In a high-performance ball mill, ball mill for 2 hours at a speed of 600r/min, put the ball-milled mixture into a mortar, weigh 0.25g of polytetrafluoroethylene (PTFE), grind it, and finally grind it with a pestle. The flaky block of one is pestled into a whole, cut it from the middle with scissors, put the two parts on the noodle press for sheeting, then put them on a glass plate, and roll them with a glass rod until Its thickness is about 0.1 mm, and it is cut into pieces of suitable size with scissors, and used as the positive electrode material of the battery. The negative electrode is made of high-purity aluminum foil with a thickness of 0.03 mm. After being sliced with a punch with a diameter of 13 mm, it is used as the negative electrode material after being polished with fine sandpaper. The ionic liquid-based electrolyte is prepared by mixing anhydrous aluminum chloride and 1-ethyl-3-methylimidazolium chloride in a molar ratio of 1.1:1. A glass fiber filter paper (GF/D, Whatman) was used as the separator. After preparing the required materials, assemble the battery in the glove box. After standing still for half an hour, use the 8-point blue battery test system (model specification: CT2001A5V10MA) to conduct the charge and discharge test. The charge and discharge voltage range is 0.6V-1.1 V, the coulombic efficiency is maintained at about 80%, and the specific capacity of the fourth discharge is 109.3mAh/g, which is close to one-half of the theoretical capacity. As the cycle progresses, the charge-discharge specific capacity gradually increases, see Figure 2 .

Example 3

The positive electrode active material is PVPI, the conductive material is Super-P, and the binder is polytetrafluoroethylene (PTFE). First, weigh 0.5g of PVPI and 0.2g of conductive material Super-P, add them to the ball mill jar, and put the ball mill jar into In a high-performance ball mill, ball mill for 2 hours at a speed of 600r/min, put the ball-milled mixture into a mortar, weigh 0.25g of polytetrafluoroethylene (PTFE), grind it, and finally grind it with a pestle. The flaky block of one is pestled into a whole, cut it from the middle with scissors, put the two parts on the noodle press for sheeting, then put them on a glass plate, and roll them with a glass rod until Its thickness is about 0.1 mm, and it is cut into pieces of suitable size with scissors, and used as the positive electrode material of the battery. The negative electrode is made of high-purity aluminum foil with a thickness of 0.03 mm. After being sliced with a punch with a diameter of 13 mm, it is used as the negative electrode material after being polished with fine sandpaper. The ionic liquid-based electrolyte is prepared by mixing anhydrous aluminum chloride and 1-ethyl-3-methylimidazolium chloride at a molar ratio of 2:1. A glass fiber filter paper (GF/D, Whatman) was used as the separator. After preparing the required materials, assemble the battery in the glove box. After standing still for half an hour, use the 8-point blue battery test system (model specification: CT2001A5V10MA) to conduct charge and discharge tests. First, set the charging voltage range to 0.6- 1.05V for activation, and then set the voltage range to 0.6-1.1V. With the change of the upper voltage limit, the coulombic efficiency does not change much, basically maintaining at about 75%, but its discharge specific capacity has increased significantly, maintaining at 180mAh/ g, see Figure 3 for details.

Example 4

The positive electrode active material is CHI ₃ , the conductive material is Liqin black, and the binder is SBR. First weigh 0.8g of CHI ₃ , and add 0.2g of conductive material into a ball mill, and put the ball mill into a high-performance ball mill. Ball milled for 2 hours at a speed of 1/min, put the ball-milled mixture into a mortar, weigh 0.1g of SBR, and grind it. Cut it from the middle with scissors, place the two parts on the noodle press for sheeting, then place them on a glass plate, roll them out with a glass rod until the thickness is about 0.1mm, and cut them out with scissors Formed into pieces of suitable size, it can be used as the positive electrode material of the battery. The negative electrode is made of high-purity aluminum foil with a thickness of 0.03 mm. After being sliced with a punch with a diameter of 13 mm, it is used as the negative electrode material after being polished with fine sandpaper. The ionic liquid-based electrolyte is prepared by mixing anhydrous aluminum chloride and 1-ethyl-3-methylimidazolium chloride at a molar ratio of 2:1. A glass fiber filter paper (GF/D, Whatman) was used as the separator. After preparing the required materials, assemble the battery in the glove box, and install a waterproof carbon paper with a thickness of 0.1-0.3mm between the separator and the positive electrode material to obtain an aluminum ion battery.

Claims (7)

1. a kind of aluminium ion battery based on the anode containing iodine, which is characterized in that comprising anode, cathode, ionic liquid base electrolyte, Diaphragm, wherein described just extremely povidon iodine or iodoform, cathode are high-purity aluminum foil, ionic liquid base electrolyte It is mixed by anhydrous aluminum chloride and 1- ethyl-3-methylimidazole chloride.

2. the aluminium ion battery according to claim 1 based on the anode containing iodine, which is characterized in that the ionic liquid base The molar ratio of anhydrous aluminum chloride and 1- ethyl-3-methylimidazole chloride is 1:1-10:1 in electrolyte.

3. the aluminium ion battery according to claim 1 based on the anode containing iodine, which is characterized in that the polyvinyl pyrrole Content of iodine is 10% in alkanone iodine (PVPI).

4. a kind of aluminium ion battery based on the anode containing iodine as described in claim 1, which is characterized in that the anode uses Load method is made, specifically includes the following steps:

(1) positive active material, conductive material, binder are weighed respectively；The positive active material is polyvinylpyrrolidine Ketone iodine (PVPI), iodoform (CHI₃), one of poly N-vinyl carbazole；The conductive material be super-P, acetylene black, One or more of Li Qinhei, the binder be polytetrafluoroethylene (PTFE) (PTFE) or the polymeric derivative with carboxyl, The polymeric derivative with carboxyl is sodium carboxymethylcellulose (CMC), Kynoar (PVDF) or butadiene-styrene rubber (SBR)；

(2) mode by weighed positive active material and conductive material grinding or ball milling is uniformly mixed；

(3) on the basis of step (2), the binder of weighing is added, grinds repeatedly, be sufficiently mixed three uniformly, obtain piece Shape material；

(4) by step (3) resulting flaky material, tabletting is carried out with noodle press, pole piece is made；

(5) it is used to be assembled into aluminium ion battery for above-mentioned pole piece as positive electrode.

5. the aluminium ion battery according to claim 4 based on the anode containing iodine, which is characterized in that by weight, anode Amount of active mass is 50-80 parts, and conductive material dosage is 10-20 parts, and consumption of binder is 10-25 parts.

6. the aluminium ion battery according to claim 1 based on the anode containing iodine, which is characterized in that between diaphragm with anode Water proof type carbon paper is additionally provided between material, thickness is between 0.1-0.3mm.

7. the aluminium ion battery according to claim 1 based on the anode containing iodine, which is characterized in that the diaphragm uses glass Glass fibrous material.