阅读说明：本技术 一种无定形碳包覆的金属硫化物及其制备方法 (Amorphous carbon-coated metal sulfide of one kind and preparation method thereof ) 是由 张宝 王春辉 李东民 欧星 张佳峰 于 2019-08-19 设计创作，主要内容包括：一种无定形碳包覆的金属硫化物及其制备方法,该无定形碳包覆的金属硫化物呈亚微米空心球形貌,粒径为500~700nm,化学通式为M<Sub>x</Sub>S<Sub>y</Sub>@C,其中,M是金属Co、Zn、Sn或Fe；其制备方法是以金属有机框架作为前驱体,然后以升华硫为硫源,利用类气相沉积法制备,或将金属有机框架与硫源混合煅烧制备,两种制备方法制备的金属硫化物,均呈亚微米空心球形貌,采用其制备的锂离子电极负极材料具备良好的导电率及循环性能。(Amorphous carbon-coated metal sulfide of one kind and preparation method thereof, the amorphous carbon-coated metal sulfide are in sub-micron hollow sphere pattern, and partial size is 500 ~ 700nm, chemical general formula M x S y @C, wherein M is metal Co, Zn, Sn or Fe；Preparation method is using metal organic frame as presoma, then using sublimed sulfur as sulphur source, it is prepared using gas-like phase sedimentation, or it prepared by metal organic frame and sulphur source mixed calcining, the metal sulfide of two kinds of preparation methods preparation, it is in sub-micron hollow sphere pattern, has good conductivity and cycle performance using its li-ion electrode negative electrode material prepared.)

1. a kind of amorphous carbon-coated metal sulfide, which is characterized in that the amorphous carbon-coated metal sulfide is in Sub-micron hollow sphere pattern, partial size are 500 ~ 700nm, chemical general formula M_xS_y@C, wherein M is metal Co, Zn, Sn or Fe.

2. amorphous carbon-coated metal sulfide according to claim 1, which is characterized in that the M_xS_y@C is CoS₂@C。

3. a kind of preparation method of amorphous carbon-coated metal sulfide as claimed in claim 1 or 2, which is characterized in that packet Include following steps:

(1) 2-methylimidazole solution is added in M salting liquid, reacts 2-30h, be centrifuged, washing, before dry metal organic frame Drive body；

(2) under atmosphere of inert gases, it is multiple to be heat-treated to obtain carbon-coated metal simple-substance to metal organic frame presoma Close object；

(3) using sublimed sulfur as sulphur source, under atmosphere of inert gases, using vapour deposition process the metal simple-substance compound base Growth obtains the unformed carbon-coated metal sulfide on bottom.

4. the preparation method of amorphous carbon-coated metal sulfide according to claim 3, which is characterized in that the M salt For one of the sulfate of metal M, nitrate, chlorate and acetate or a variety of；Preferably, the 2-methylimidazole and M The mass ratio of the material of M element is 1 ~ 100:1 in salt；Preferably, the concentration of M element is 0.005 ~ 0.1mol/ in the M salting liquid L；Preferably, the concentration of the 2-methylimidazole solution is 0.01 ~ 10mol/L；Preferably, in the step (1), the reaction Temperature be 0 DEG C ~ 40 DEG C；Preferably, the solvent of the M salting liquid and 2-methylimidazole solution be selected from water, ethyl alcohol, methanol and One or more of ethylene glycol；More preferably, the solvent of the M salting liquid and 2-methylimidazole solution is methanol.

5. according to the preparation method of the amorphous carbon-coated metal sulfide of claim 3 or 4, which is characterized in that described The temperature of heat treatment is 400 ~ 1000 DEG C；More preferably, the heat treatment temperature is 600 ~ 800 DEG C；Preferably, at the heat The time of reason is 0.5 ~ 2h.

6. according to the preparation method of any one of the claim 3-5 amorphous carbon-coated metal sulfide, which is characterized in that The mass ratio of the sublimed sulfur and metal simple-substance compound is 5 ~ 50:1；Preferably, in the vapour deposition process, vapor deposition Temperature is 200 ~ 600 DEG C；Preferably, in the vapour deposition process, the time of vapor deposition is 0.5 ~ 10h；The vapor deposition In method, the flow velocity of air-flow is 80-200 mL/min.

7. the preparation method of amorphous carbon-coated metal sulfide according to claim 3, which is characterized in that the step (2) it is replaced with (3) by following steps S, the particular content of step S are as follows: there is machine frame presoma and sulphur source to grind on the metal mixed It closes, carries out calcination processing under atmosphere of inert gases, after the completion of calcination processing, cooling obtains the amorphous carbon-coated metal Sulfide.

8. the preparation method of amorphous carbon-coated metal sulfide according to claim 7, which is characterized in that the M salt For one of the sulfate of metal M, nitrate, chlorate and acetate or a variety of；Preferably, M element and 2- in the M salt The mass ratio of the material of methylimidazole is 1 ~ 100；Preferably, the concentration of M element is 0.005 ~ 0.1mol/L in the M salting liquid； Preferably, the concentration of the 2-methylimidazole solution is 0.01 ~ 10mol/L；Preferably, in the step (1), the reaction Temperature is 0 DEG C ~ 40 DEG C；Preferably, the solvent of the M salting liquid and 2-methylimidazole solution is selected from water, ethyl alcohol, methanol and second One or more of glycol；More preferably, the solvent of the M salting liquid and 2-methylimidazole solution is methanol.

9. according to the preparation method of the amorphous carbon-coated metal sulfide of claim 7 or 8, which is characterized in that described In step S, the sulphur source is selected from one of sublimed sulfur, thioacetamide and L-cysteine or a variety of；Preferably, the step In rapid S, the mass ratio of the sulphur source and metal organic frame is 10 ~ 100:1；Preferably, in the step S, at the calcining The temperature of reason is 400 ~ 900 DEG C.

10. according to the preparation method of any one of the claim 3-9 amorphous carbon-coated metal sulfide, feature exists In the inert gas is nitrogen, argon gas, the nitrogen containing 1 ~ 10% hydrogen or the argon gas for containing 1 ~ 10% hydrogen.

Technical field

The present invention relates to lithium ion battery negative material fields, and in particular to a kind of amorphous carbon-coated metal sulfide And preparation method thereof.

Background technique

Lithium ion battery be it is current apply energy storage device the most universal, be widely used in electric vehicle, electric bicycle, 3C electronic product or even space flight and aviation.With the increase of people's demand, lithium ion battery is just sent out towards the direction of high specific energy Exhibition, the lithium ion battery electrode material for developing Fabrication of High Specific Capacitance become current lithium secondary battery and expand one of the key promoted and applied.

Currently, main lithium ion battery negative material is mainly include the following types: Carbon materials are current the most universal Commercial li-ion cell negative electrode material, but because of its lower theoretical specific capacity (374 mAh/g), the material is seriously limited in height Than the application in energy lithium ion battery.Silicon substrate class battery material theoretical specific capacity with higher (4200 mAh/g), but the material Material has 300% volume expansion in the lithium storage process, so that its cycle performance and security performance reduce.Metal phosphorizing species lithium from Sub- cell negative electrode material, although cyclic specific capacity with higher, which generates with hypertoxic gas during the preparation process, It is unfavorable for widespread adoption.Metal sulfide, metal selenide all have higher theoretical specific capacity, compared with metal selenide, gold Belonging to sulfide has higher theoretical capacity, and cycle performance is more preferably.But such material equally has certain volume expansion, leads The problems such as electrically bad.

CN109713267A discloses a kind of novel cathode material for lithium ion battery and preparation method thereof, uses calcining sulphur ZIF8 after change is compound by being spray-dried with graphene, obtains spherical ZnS composite graphite ene product.The program passes through forerunner Body preparation, calcining vulcanization, spraying moulding, process is complicated；Importantly, it utilizes the spheric granules that means obtain by spraying It is physical bond means, stablizes far from chemical bond, be easy to cause the collapsing of material structure during circulating battery；In addition with regard to performance For, capacity retention ratio is probably only 62% after 100 circle circulations under the small multiplying power of modified material (0.2C), poor performance.

Summary of the invention

The technical problems to be solved by the present invention are: overcoming the deficiencies of the prior art and provide a kind of amorphous carbon-coated The metal sulfide of metal sulfide and preparation method thereof, the preparation method preparation is in sub-micron hollow sphere, can be effectively relieved The volume expansion of material in cyclic process；Has good conduction using lithium cell cathode material prepared by the metal sulfide Rate and stable cycle performance.

The technical solution adopted by the present invention to solve the technical problems is: a kind of amorphous carbon-coated metal sulfide, It is in sub-micron hollow sphere pattern, and partial size is 500 ~ 700nm, chemical general formula M_xS_y@C, wherein M is metal Co, Zn, Sn, Fe One of, preferably Co.

Preferably, the M_xS_yFor CoS₂。

The preparation method of the amorphous carbon-coated metal sulfide of the present invention, comprising the following steps:

(1) 2-methylimidazole solution is added in M salting liquid, reacts 2h-30h, be centrifuged, washing, dry metal organic frame Presoma；

(2) under atmosphere of inert gases, it is multiple to be heat-treated to obtain carbon-coated metal simple-substance to metal organic frame presoma Close object；

(3) using sublimed sulfur as sulphur source, under the atmosphere of inert gas, using vapour deposition process in the metal simple-substance compound Growth obtains the unformed carbon-coated metal sulfide in substrate.

Preferably, the M salt is one of sulfate, nitrate, chlorate and acetate of metal M or a variety of.

Preferably, the mass ratio of the material of the M salt and 2-methylimidazole is 1 ~ 100:1.

Preferably, the concentration of the M salting liquid is 0.005 ~ 0.1mol/L.

Preferably, the concentration of the 2-methylimidazole solution is 0.01 ~ 10mol/L.

Preferably, in the step (1), the temperature of the reaction is 0 DEG C ~ 40 DEG C.

Preferably, the solvent of the M salting liquid and 2-methylimidazole solution is selected from water, ethyl alcohol, methanol and ethylene glycol One or more；More preferably, the solvent of the M salting liquid and 2-methylimidazole solution is methanol.

Preferably, the temperature of the heat treatment is 400 ~ 1000 DEG C.

More preferably, the heat treatment temperature is 600 ~ 800 DEG C.

Preferably, the time of the heat treatment is 0.5 ~ 2h.

Preferably, the inert gas is nitrogen, argon gas, the nitrogen containing 1 ~ 10% hydrogen or the argon for containing 1 ~ 10% hydrogen Gas.

Preferably, the mass ratio of the sublimed sulfur and metal simple-substance compound is 5 ~ 50:1.

Preferably, in the vapour deposition process, the temperature of vapor deposition is 200 ~ 600 DEG C.

Preferably, in the vapour deposition process, the time of vapor deposition is 0.5 ~ 10h.

Preferably, in the vapour deposition process, the flow velocity of air-flow is 80-200 mL/min.

Preferably, the step (2) and (3) are replaced by following steps S, the particular content of step S are as follows: have the metal After machine frame presoma and sulphur source ground and mixed, calcination processing is carried out under atmosphere of inert gases, after the completion of processing, cooling obtains institute State amorphous carbon-coated metal sulfide.

Preferably, in the step S, the sulphur source is selected from one of sublimed sulfur, thioacetamide and L-cysteine Or it is a variety of.

Preferably, in the step S, the mass ratio of the sulphur source and metal organic frame is 10 ~ 100:1.

Preferably, in the step S, the temperature of the calcination processing is 400 ~ 900 DEG C.

The beneficial effects of the present invention are:

1. amorphous carbon-coated metal sulfide of the invention is in sub-micron hollow sphere pattern, partial size is 500 ~ 700nm, hollow The volume expansion as negative electrode material in cyclic process can be effectively relieved in structure, increase the reaction site of negative electrode material, promoted The structural stability of negative electrode material improves the stable circulation performance of negative electrode material in turn；

2. preparation method of the invention prepares hollow sphere first by the strategies such as adjusting solvent amount and component, metal salt type The metal organic frame presoma of shape；Then thermally treated, so that organic ligand in-situ carburization forms agraphitic carbon cladding；It is sharp again Calcining vulcanization or dinectly bruning vulcanization is carried out with gas-like phase sedimentation to maintain by conditions such as the temperature and times of control calcining Metal organic frame presoma obtains hollow structure and carries out S and deposits to obtain metal sulfide of the invention, which is in Hollow spheroidal particle, and chemical bonds S is utilized, compared with subsequent spray pelletizing, there is better structural stability, and the spherical shape Particle is also wrapped on amorphous carbon, so that the negative electrode material of metal sulfide preparation has good lithium ion battery electrification Learn performance.

Detailed description of the invention

Fig. 1 is the XRD diagram of product prepared by the embodiment of the present invention 1；

Fig. 2 is the SEM figure of product prepared by the embodiment of the present invention 2；

Fig. 3 is the cycle performance figure of product prepared by the embodiment of the present invention 2.

Specific embodiment

The present invention is further detailed with attached drawing with reference to embodiments.