CN108598475B

CN108598475B - Phosphorus-sulfur-selenium series cathode material with adjustable component structure for ion battery

Info

Publication number: CN108598475B
Application number: CN201810379025.5A
Authority: CN
Inventors: 余家乐; 张海燕; 李文武; 张宇杰
Original assignee: Guangdong University of Technology
Current assignee: Guangdong University of Technology
Priority date: 2018-04-25
Filing date: 2018-04-25
Publication date: 2021-03-26
Anticipated expiration: 2038-04-25
Also published as: CN108598475A

Abstract

The invention belongs to the field of ion battery materials, and particularly relates to a phosphorus-sulfur-selenium series negative electrode material with an adjustable component structure for an ion battery. The invention provides an ion battery cathode material, which comprises the following components: amorphous state of P₄S_xSe_3‑x(ii) a Wherein x is 0 or 1 or 2 or 3. The invention also provides a preparation method of the negative electrode material of the ion battery, and the application of the negative electrode material of the ion battery or a product obtained by the preparation method in the field of lithium ion batteries and/or sodium ion batteries. The product prepared by the technical scheme provided by the invention has the advantages of high capacity, good rate capability and good cycle performance; the amorphous product structure of the product is easier to recover in a short-range ordered structure, and is beneficial to keeping the stability of the electrode material in the charging and discharging processes; the technical defects of low capacity, poor rate capability and poor cycle stability of the cathode material of the ion battery in the prior art are overcome.

Description

Phosphorus-sulfur-selenium series cathode material with adjustable component structure for ion battery

Technical Field

The invention belongs to the field of ion battery materials, and particularly relates to a phosphorus-sulfur-selenium series negative electrode material with an adjustable component structure for an ion battery.

Background

The increasingly depleted non-renewable energy and the constantly deteriorating natural environment have stimulated the pursuit of new renewable energy by mankind. Therefore, human beings continuously develop new renewable energy sources such as wind energy, solar energy, tidal energy and the like, and store the renewable energy sources by using a static energy storage power station so as to improve the energy utilization efficiency. Meanwhile, electric vehicles and portable electronic devices gradually come into the lives of people. Currently, in the field of energy storage, lithium ion batteries have been used in the fields of mobile energy storage such as 3C electronic products and electric vehicles due to their advantages of environmental protection, high energy density, high operating voltage, and the like; the energy density of the sodium ion battery is lower than that of the lithium ion battery, but the sodium ion battery benefits from the abundant sodium resource of the earth and has relatively low economic cost, so that the sodium ion battery can be used in the static energy storage fields of UPS power supplies, communication base station power supplies, pumped storage power stations, industrial heat storage systems and the like.

At present, most of commercial lithium ion batteries adopt graphite as a negative electrode material, but the theoretical capacity of the lithium ion batteries is only 372mAh g^-1And can not meet the current market demand. In addition, graphite has problems of poor rate capability, lithium dendrite, and the like. At present, carbon-based materials, silicon-based materials and tin-based materials, which are much attention paid by researchers, cannot meet the current needs due to the problems of poor cycle stability caused by small specific capacity and volume expansion. In addition, a very important indicator for battery applications is cycling performance. The crystal material has a regular crystal structure, so that the structure is easy to collapse after multiple charge and discharge cycles, and the cycle performance is poor.

Therefore, the development of phosphorus-sulfur-selenium series negative electrode materials with adjustable component structures for ion batteries is used for solving the technical defects of low capacity, poor rate capability and poor cycle stability of the negative electrode materials of the ion batteries in the prior art, and the problem to be solved by the technical staff in the field is urgently needed.

Disclosure of Invention

In view of the above, the invention provides a phosphorus-sulfur-selenium series negative electrode material with an adjustable component structure for an ion battery, which is used for solving the technical defects of low capacity, poor rate capability and poor cycle stability of the negative electrode material of the ion battery in the prior art.

The invention provides an ion battery cathode material, which comprises the following components in parts by weight: amorphous state of P₄S_xSe_3-x(ii) a Wherein x is 0 or 1 or 2 or 3.

The invention also provides a preparation method of the ion battery cathode material, which comprises the following steps: mixing phosphorus powder, sulfur powder and selenium powder, and ball-milling to obtain a product;

wherein, the ball milling process is carried out under the protection of inert gas.

Preferably, the feeding ratio of the phosphorus powder, the sulfur powder and the selenium powder is (3.9-4.1): (0-3): 0-3) in terms of molar parts.

Preferably, the ball mass ratio of the ball milling is (20-25): 1.

Preferably, the rotation speed of the ball milling is 1100-1200 r/min, and the ball milling time is 5-10 h.

Preferably, the inert gas is nitrogen and/or argon.

Preferably, the ball milling tank and the ball milling beads of the ball mill are made of the same material.

Preferably, the material of the ball milling tank is stainless steel or hard alloy.

The invention also provides an application of the negative electrode material of the ion battery or the product obtained by the preparation method in the field of lithium ion batteries and/or sodium ion batteries.

In summary, the present invention provides an ion battery anode material, which is: amorphous state of P₄S_xSe_3-x(ii) a Wherein x is 0 or 1 or 2 or 3. The invention also provides a preparation method of the ion battery cathode material, which comprises the following steps: mixing phosphorus powder, sulfur powder and selenium powder, and ball-milling to obtain a product; wherein, the ball milling process is carried out under the protection of inert gas. The invention also provides an application of the negative electrode material of the ion battery or the product obtained by the preparation method in the field of lithium ion batteries and/or sodium ion batteries. The product prepared by the technical scheme provided by the invention has the advantages of high capacity, good rate capability and good cycle performance; the amorphous product structure of the product is easier to recover from the short-range ordered structure, and is beneficial to keeping the stability of the electrode material in the charging and discharging processes. The phosphorus-sulfur-selenium series cathode material with the adjustable component structure for the ion battery solves the problem that the cathode material of the ion battery has low capacity in the prior artPoor rate capability and poor cycle stability.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is P₄SSe₂X-ray diffraction pattern of elemental substance P, S, Se;

FIG. 2 is P₄Se₃X-ray diffraction pattern of

FIG. 3 is P₄SSe₂A spectrum of (a);

FIG. 4 is P₄SSe₂Taking the curve as a charge-discharge curve of a negative electrode material of the lithium ion battery;

FIG. 5 is P₄SSe₂The material is used as a charge-discharge curve of a negative electrode material of a sodium ion battery.

Detailed Description

The embodiment of the invention provides a phosphorus-sulfur-selenium series cathode material with an adjustable component structure for an ion battery, which is used for solving the technical defects of low capacity, poor rate capability and poor cycle stability of the cathode material of the ion battery in the prior art.

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In order to explain the present invention in more detail, the following describes the phosphorus-sulfur-selenium series anode material with adjustable composition structure for ion batteries specifically with reference to the examples.

Example 1

This example is to prepare amorphous P₄S₃In the following description.

2.8147g of phosphorus powder with the purity of 99.9 percent and 2.1853g of sulfur powder with the purity of 99.9 percent are respectively weighed and mixed, and are ball-milled for 10 hours in a ball-milling tank under the protection of nitrogen and the conditions that the ball mass ratio is 25:1 and the rotating speed is 1200r/min to obtain P₄S₃(ii) a Wherein, the ball milling pot and the ball milling beads are made of stainless steel.

And (3) obtaining a prepared sample with an atomic ratio of P: S-4: 3 and an amorphous substance by X-ray diffraction analysis and element quantitative analysis.

Example 2

This example is to prepare amorphous P₄Se₃In the following description.

1.7171g of phosphorus powder with the purity of 99.9 percent and 3.2829g of selenium powder with the purity of 99.9 percent are respectively weighed and mixed, and are ball-milled for 10 hours in a ball-milling tank under the protection of argon gas and the conditions that the ball mass ratio is 25:1 and the rotating speed is 1200r/min to obtain P₄Se₃(ii) a Wherein, the ball milling pot and the ball milling beads are made of hard alloy.

And (3) obtaining a prepared sample with an atomic ratio of P to Se of 4 to 3 and an amorphous substance by X-ray diffraction analysis and element quantitative analysis.

Example 3

This example is to prepare amorphous P₄SSe₂In the following description.

1.9736g of phosphorus powder with the purity of 99.9 percent, 0.5108g of sulfur powder with the purity of 99.9 percent and 2.5156g of selenium powder with the purity of 99.9 percent are respectively weighed and mixed, and are ball-milled for 10 hours in a ball-milling tank under the protection of mixed gas of nitrogen and argon, the ball mass ratio is 25:1 and the rotating speed is 1100r/min, so that P is obtained₄SSe₂(ii) a Wherein, the ball milling pot and the ball milling beads are made of stainless steel.

By X-ray diffraction analysis and element quantitative analysis, the prepared sample has the atomic ratio of P to S to Se of 4 to 1 to 2, and is an amorphous substance.

Example 4

This example is to prepare amorphous P₄S₂Specific examples of Se.

2.3212g of phosphorus powder with the purity of 99.9 percent, 1.2014g of sulfur powder with the purity of 99.9 percent and 1.4795g of selenium powder with the purity of 99.9 percent are respectively weighed and mixed, and are ball-milled for 10 hours in a ball-milling tank under the protection of mixed gas of nitrogen and argon, the ball mass ratio is 25:1 and the rotating speed is 1200r/min, so that P is obtained₄S₂Se; wherein, the ball milling pot and the ball milling beads are made of stainless steel.

By X-ray diffraction analysis and element quantitative analysis, the prepared sample has the atomic ratio of P to S to Se of 4 to 2 to 1, and is an amorphous substance.

Example 5

This example is a specific example of measuring the X-ray diffraction pattern of the products obtained in examples 1 to 4.

The measurement results are shown in FIG. 1 and FIG. 2, where P is shown in FIG. 1₄SSe₂Comparison with the X-ray diffraction of the simple substance P, S, Se, P in FIG. 2₄Se₃X-ray diffraction pattern of (a).

As can be seen from FIG. 1, P is₄SSe₂The X-ray diffraction results of (A) are different from those of P, S, Se elementary substance. And, P₄SSe₂Diffraction peak of (2) and standard PDF card (P)₄SSe₂: PDF #44-1062), P₄Se₃Diffraction peak of (2) and standard PDF card (P)₄Se₃: PDF #27-0361), indicating successful sample preparation.

In addition, P₄Se₃And P₄SSe₂The diffraction peak signal is very weak, only two weak 'steamed bread peaks' exist, and the P prepared by the high-energy ball milling method is preliminarily shown₄Se₃And P₄SSe₂The diffraction peak of the phosphorus-sulfur-selenium compound is an amorphous compound.

P₄S₂Se and P₄S₃The measurement results are similar to the above results and are not described in detail herein.

Example 6

This example is an energy spectrum of the product obtained in examples 1 to 4.

The results of the measurements are shown in FIG. 3, where P is shown in FIG. 3₄SSe₂Energy spectrum of (2).

As can be seen from fig. 3, the compound consists of P, S, Se three elements, and the atomic ratio is P: S: Se ═ 3.951:1:1.993, very close to 4:1:2, with small amounts of foreign elements such as copper, carbon coming from the test copper mesh and the contaminating carbon source, respectively. Thus illustrating the method for preparing P₄SSe₂Phosphorus sulfur selenium compounds are feasible.

And (4) measuring energy spectrums of the other three compounds, wherein the atomic ratio of each product is the same as that of the target compound, and the details are not repeated.

Example 7

This example is a specific example of observing the structure of the product prepared in examples 1 to 4 using a scanning electron microscope.

The microscopic appearance of the prepared product is nano particles, and the smaller primary particle clusters are excessively agglomerated to form larger secondary particles, so that the transmission and permeation of electrolyte are facilitated, and most importantly, the tap density of an electrode is improved, and finally, the energy density of the whole battery is improved.

Example 8

The present embodiment is a specific embodiment of observing the structure of the product prepared in embodiments 1 to 4 by using a transmission electron microscope, and performing corresponding detection on the electron diffraction pattern thereof.

The prepared products are all in typical amorphous structures as can be seen from the field of view of the microscope; the amorphous structure material can reserve a large amount of buffer space for volume expansion in the charging and discharging process, so that the electrode material is not easy to pulverize and fall off. More importantly, the short-range ordered structure makes the structure recovery relatively easy, thereby being beneficial to keeping the electrode material stable in the charging and discharging process.

Example 9

This example is a specific example of the constant current charge-discharge test curves of lithium ion batteries and sodium ion batteries using the products prepared in examples 1 to 4 as the negative electrodes, respectively.

Wherein, FIG. 4 shows the case of P₄SSe₂FIG. 5 shows the charge/discharge curve of a negative electrode lithium ion battery using P₄SSe₂As negative electrode sodium ionThe charge and discharge curve of the battery.

In a lithium ion battery, P₄SSe₂The lithium storage capacity is up to 1456mAh/g, which is close to the theoretical lithium storage capacity (1537mAh/g), and the first coulombic efficiency is up to 86%. In sodium ion batteries, P₄SSe₂The sodium storage capacity is up to 813mAh/g, and the first coulombic efficiency is up to 80%.

The above assay was repeated for the remaining three compounds, all of which gave similar experimental results, and will not be described further herein.

In the invention, the research focus is changed to the research of phosphorus and VIA composite materials (sulfur and selenium) and aims to synthesize amorphous P₄S_xSe_3-x(X is more than or equal to 0 and less than or equal to 3) negative electrode material. Selenium (Se) has good conductivity (approximatively 10-5S cm-1) and high theoretical specific capacity (678mA h g-1); meanwhile, the presence of P — Se bonds can inhibit the dissolution of Se and its reaction intermediates in the electrolyte.

Further, the sulfur-rich phosphorus sulfur compound has lithium and sodium storage properties different from those of sulfur, which has higher conductivity, thereby exhibiting excellent lithium storage capacity. At the same time, due to the existence of P-S bond, P is enabled₄S_xSe_3-x(X is more than or equal to 0 and less than or equal to 3) has higher cycle stability. In addition, a large amount of buffer space can be reserved for volume expansion in the charge-discharge process of the amorphous structure material, so that the electrode material is not easy to pulverize and fall off. More importantly, the short-range ordered structure makes the structure recovery relatively easy, thereby being beneficial to keeping the electrode material stable in the charging and discharging process.

In the technical scheme provided by the invention, P, S, Se is compounded at the same time to prepare the amorphous P-S-Se material. Because the three elements are all high-capacity elements, the three elements are used in the same system to be beneficial to generating P with high capacity and high cycling stability₄S_xSe_3-x(X is more than or equal to 0 and less than or equal to 3) electrode material.

S, Se the intermediate products of the reaction process are readily soluble in the electrolyte, leading to rapid capacity fade and reduced cell cycling stability. Therefore, in the invention, P-S bond and P-Se bond are introduced, thereby reducing the shuttle effect of S and Se through chemical recombination. Document retrieval systemAt present, there is no P₄S_xSe_3-x(X is more than or equal to 0 and less than or equal to 3) in the aspect of electrochemical work.

The preliminary research shows that the system is used as the lithium ion battery cathode material, and the specific capacity is 1500-^-1In between, the first coulombic efficiency is about 80%.

Meanwhile, EIS test and CV test show that the material has better reaction kinetics, and Li⁺And Na⁺The transmission speed is faster, which corresponds to its superior rate capability. The above results show that P₄S_xSe_3-x(0. ltoreq. X. ltoreq.3) is an excellent electrode material.

According to the technical scheme, the phosphorus-sulfur-selenium series cathode material with the adjustable component structure for the ion battery has the following advantages:

(1) the invention provides a method for preparing P₄S_xSe_3-x(X is more than or equal to 0 and less than or equal to 3) the method of the cathode material is beneficial to improving the production efficiency. The high-energy ball milling method can be adopted to prepare the P in large batch and large scale₄S_xSe_3-x(X is more than or equal to 0 and less than or equal to 3) negative electrode material. Compared with the traditional chemical synthesis, the production process can be monitored by a machine program without complex manual operation and complex calculation, so that the production efficiency can be greatly improved. In addition, the high-energy ball milling method can easily prepare amorphous P₄S_xSe_3-x(X is more than or equal to 0 and less than or equal to 3), and has great technical progress compared with the defects of complex preparation method, high cost and low yield of the traditional amorphous material.

(2) P prepared by the invention₄S_xSe_3-x(X is more than or equal to 0 and less than or equal to 3) the cathode material is used for the cathode of the lithium ion battery and the sodium ion battery, which is beneficial to improving the cycle performance of the battery. At present, most of negative electrode materials of lithium ion batteries and sodium ion batteries are crystal materials, and the crystal materials have regular crystal structures, so that the structures are easily collapsed after multiple charge and discharge cycles, and the cycle performance is poor. P prepared by the invention₄S_xSe_3-x(X is more than or equal to 0 and less than or equal to 3) the negative electrode material is in an amorphous structure, and the amorphous material has an amorphous structureThe structure, so there is no problem of structural damage. In addition, a large amount of buffer space can be reserved for volume expansion in the charging and discharging process of the amorphous material, so that the electrode material is not easy to pulverize and fall off. More importantly, the short-range order structure makes the structure recovery relatively easy. Therefore, the lithium ion battery and the sodium ion battery can have good cycle stability when applied to the lithium ion battery and the sodium ion battery.

(3) P prepared by the invention₄S_xSe_3-x(X is more than or equal to 0 and less than or equal to 3) the negative electrode material is used for the negative electrode of the lithium ion battery and the sodium ion battery and is beneficial to improving the specific capacity of the battery. Since P, S, Se elements have large theoretical capacity, the material prepared by highly compounding two or three elements also has large capacity, such as P₄SSe₂The theoretical lithium storage capacity of the graphite material is as high as 1537mAh/g, which is far higher than that of the conventional graphite material (372 mAh/g).

(4) P prepared by the invention₄S_xSe_3-x(X is more than or equal to 0 and less than or equal to 3) the cathode material is used for the cathode of the lithium ion battery and the sodium ion battery, and is beneficial to improving the first coulombic efficiency and the rate capability of the battery. In the traditional lithium-sulfur battery, sodium-sulfur battery, lithium-selenium battery and sodium-selenium battery, because sulfur and selenium elements have shuttle effect, an intermediate product in the electrode reaction process can be dissolved in electrolyte, so that the first coulombic efficiency and rate capability are reduced. However, in the present invention, P₄S_xSe_3-x(X is more than or equal to 0 and less than or equal to 3) in the cathode material system, due to the P-S bond and the P-Se bond formed in the high-energy ball milling process, the strong interaction of the chemical bonds ensures that S, Se and reaction intermediate products thereof are not dissolved in the electrolyte, thereby greatly improving the first coulombic efficiency and rate capability of the battery.

(5) P prepared by the invention₄S_xSe_3-x(X is more than or equal to 0 and less than or equal to 3) the cathode material is used for the cathode of the lithium ion battery and the sodium ion battery, which is beneficial to improving the reaction kinetics of the battery. The P-S bond and the P-Se bond formed in the high-energy ball milling process enable the microstructure of the electrode material to be kept stable, S, Se and reaction intermediate products thereof are not dissolved in the electrolyte, so that the electrolyte always keeps higher ionic conductivity, and the impedance of the battery is not reduced. In addition, electrolytic reactionIn the process, a fast ion conductor is generated, so that the ionic conduction of the battery is greatly improved, the electrochemical polarization of the material is reduced, and the reaction kinetics of the material is improved.

In summary, the present invention provides an ion battery anode material, which is: amorphous state of P₄S_xSe_3-x(ii) a Wherein x is 0 or 1 or 2 or 3. The invention also provides a preparation method of the ion battery cathode material, which comprises the following steps: mixing phosphorus powder, sulfur powder and selenium powder, and ball-milling to obtain a product; wherein, the ball milling process is carried out under the protection of inert gas. The invention also provides an application of the negative electrode material of the ion battery or the product obtained by the preparation method in the field of lithium ion batteries and/or sodium ion batteries. The product prepared by the technical scheme provided by the invention has the advantages of high capacity, good rate capability and good cycle performance; the amorphous product structure of the product is easier to recover from the short-range ordered structure, and is beneficial to keeping the stability of the electrode material in the charging and discharging processes. The phosphorus-sulfur-selenium series cathode material with the adjustable component structure for the ion battery provided by the invention solves the technical defects of low capacity, poor rate capability and poor cycle stability of the cathode material of the ion battery in the prior art.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. The negative electrode material of the ion battery is characterized by comprising the following components in parts by weight: amorphous state of P₄S_xSe_3-x(ii) a Wherein x is 1 or 2;

the preparation method of the negative electrode material of the ion battery comprises the following steps: mixing phosphorus powder, sulfur powder and selenium powder, and ball-milling to obtain a product;

wherein, the ball milling process is carried out under the protection of inert gas;

the ball mass ratio of the ball milling is (20-25) to 1;

the rotating speed of the ball milling is 1100-1200 r/min, and the ball milling time is 5-10 h.

2. The negative electrode material for ion batteries of claim 1, wherein the ratio of phosphorus powder, sulfur powder and selenium powder is (3.9-4.1): (0-3): 0-3).

3. The ion battery anode material according to claim 1, wherein the inert gas is nitrogen and/or argon.

4. The negative electrode material for the ion battery as claimed in claim 1, wherein the ball milling pot and the ball milling beads are made of the same material.

5. The negative electrode material for the ion battery as claimed in claim 4, wherein the material of the ball milling pot is stainless steel or hard alloy.

6. The application of the negative electrode material of the ion battery as claimed in any one of claims 1 to 5 in the field of lithium ion batteries and/or sodium ion batteries.