阅读说明：本技术 一种双阴离子钴基硒硫化物及其制备方法 (A kind of dianion cobalt-based selenium sulfide and preparation method thereof ) 是由 欧星 王春辉 叶隆 张宝 张佳峰 于 2019-08-19 设计创作，主要内容包括：一种双阴离子钴基硒硫化物及其制备方法；该双阴离子钴基硒硫化物的化学通式是Co<Sub>0.85</Sub>Se<Sub>1-x</Sub>S<Sub>x</Sub>@rGO,其中,0＜x≤0.5。其制备方法首先采用钴盐与2-甲基咪唑反应生成前驱体,然后将前驱体和氧化石墨烯混合,使前驱体附着在氧化石墨烯表面,最后加入硫源和硒源,进行水热反应,同步实现硫源和硒源与前驱体中钴结合形成还原氧化石墨烯均匀缠绕、体相S掺杂的Co<Sub>0.85</Sub>Se颗粒,即得到所述双阴离子钴基硒硫化物,采用该双阴离子钴基硒硫化物制备的电池负极材料具有良好的导电性能和优异的循环稳定性。(A kind of dianion cobalt-based selenium sulfide and preparation method thereof；The chemical general formula of the dianion cobalt-based selenium sulfide is Co 0.85 Se 1‑x S x @rGO, wherein 0 x≤0.5 <.Preparation method uses cobalt salt to react with 2-methylimidazole first and generates presoma, then presoma and graphene oxide are mixed, presoma is set to be attached to surface of graphene oxide, it is eventually adding sulphur source and selenium source, carry out hydro-thermal reaction, the synchronous Co for realizing sulphur source and selenium source and forming redox graphene uniform winding, body phase S doping in conjunction with cobalt in presoma 0.85 Se particle is had good conductive property and excellent cyclical stability to get the dianion cobalt-based selenium sulfide is arrived using cell negative electrode material prepared by the dianion cobalt-based selenium sulfide.)

1. a kind of dianion cobalt-based selenium sulfide, which is characterized in that the chemical general formula of the dianion cobalt-based selenium sulfide It is Co_0.85Se_1-xS_x@rGO, wherein 0 x≤0.5 <.

2. dianion cobalt-based selenium sulfide according to claim 1, which is characterized in that the dianion cobalt-based selenium sulphur In compound, Co_0.85Se_1-xS_xThe hollow polyhedral for being 200 ~ 400 nm in partial size, surface layer is uniformly twined by redox graphene Around.

3. the preparation method of dianion cobalt-based selenium sulfide as claimed in claim 1 or 2, which is characterized in that use cobalt salt first It is reacted with 2-methylimidazole and generates presoma, then presoma and graphene oxide are mixed, presoma is made to be attached to oxidation stone Black alkene surface is eventually adding sulphur source and selenium source, carries out hydro-thermal reaction, synchronous to realize sulphur source and the selenium source shape in conjunction with cobalt in presoma The Co adulterated at redox graphene uniform winding, body phase S_0.85Se particle.

4. preparation method according to claim 3, which is characterized in that the preparation method comprising the following specific steps

(1) 2-methylimidazole solution is added in Co salting liquid, stands reaction, be separated by solid-liquid separation, wash solid, dry forerunner Body；

(2) selenium powder is dispersed in solvent I, reducing agent is then added, reaction to selenium powder is all restored；

(3) it disperses the presoma and graphene oxide in solvent II and forms suspension, sulphur source solution is added and selenium source is molten Liquid forms reaction solution, is warming up to 150 ~ 200 DEG C, reacts 4 ~ 30h, is separated by solid-liquid separation, and washs, dry, obtains the dianion cobalt-based Selenium sulfide.

5. preparation method according to claim 3 or 4, which is characterized in that the substance of element sulphur and selenium powder in the sulphur source Amount ratio be 0.5 ~ 3.5:1；More preferably, the mass ratio of the material of element sulphur and selenium powder is 1 ~ 3:1 in the sulphur source；It is preferred that , the sum of amount of substance of selenium element is 1 in element sulphur and selenium powder in the amount and sulphur source of the substance of Co element in the presoma: 1~10。

6. according to the described in any item preparation methods of claim 3-5, which is characterized in that the graphene oxide and presoma Mass ratio is 1:5 ~ 30, it is preferred that the mass ratio of the graphene oxide and presoma is 1:8 ~ 15；Preferably, described suspended In liquid, the concentration of presoma is 1-10 mg/L.

7. according to the described in any item preparation methods of claim 3-6, which is characterized in that the concentration of the sulphur source solution is 0.05 ~0.5 mol/L；Preferably, the sulphur source is selected from one of thioacetamide, vulcanized sodium and ammonium sulfide or a variety of；Preferably, Solvent and solvent II in the sulphur source solution are selected from one of water, ethyl alcohol, ethylene glycol and methanol or a variety of；Preferably, The solvent I is water or ethyl alcohol；More preferably, the solvent of the sulphur source solution and solvent II are water, and the solvent I is second Alcohol.

8. according to the described in any item preparation methods of claim 3-7, which is characterized in that the substance of the reducing agent and selenium powder Measure 1 ~ 4:1 of ratio；Preferably, the reducing agent is sodium borohydride or hydrazine hydrate；Preferably, in the selenium source solution selenium element it is dense Degree is 0.01 ~ 0.5mol/L；Preferably, the temperature that the selenium powder is reacted with reducing agent is -10 ~ 10 DEG C.

9. according to the described in any item preparation methods of claim 3-8, which is characterized in that the cobalt salt is selected from cobaltous sulfate, nitric acid Cobalt, cobalt chloride and cobalt acetate and four one of hydrate or a variety of；Preferably, cobalt element and 2- first in the cobalt salt The mass ratio of the material of base imidazoles is 0.01 ~ 0.35:1；Preferably, in the cobalt salt substance of cobalt element and 2-methylimidazole amount Than for 0.2:1；Preferably, the concentration of the cobalt salt solution is 0.01 ~ 0.15mol/L；Preferably, the time for standing reaction For 10 ~ 30h.

10. according to the described in any item preparation methods of claim 3-9, which is characterized in that in the step (3), the reaction 180 DEG C of temperature；Preferably, the time of the reaction is 14 ~ 16h.

Technical field

The invention belongs to anode material of lithium-ion battery fields, and in particular to a kind of dianion cobalt-based selenium sulfide and its Preparation method.

Background technique

With the irreversible consumption of fossil energy, new energy more at indispensable part in for people's lives, wherein The application of lithium ion battery is the most universal.However as the continuous consumption of lithium resource, deficient lithium resource has seriously limited not Carry out the widespread adoption of lithium ion battery.Sodium resource earth rich reserves, relative price is cheap, and sodium-ion battery also has become The emphasis of academia and industrial circle exploitation.But the problem that sodium-ion battery is low there are still energy density, do not meet the following height Than that can develop with high-power direction, this requires develop the sodium ion battery electrode material of high capacity.

The lithium ion battery negative material of high capacity mainly has silica-base material, metal oxide, metal sulfide and metal Selenides etc..But since the ionic radius of sodium ion (r=1.06) are greater than the ionic radius (r=0.76) of lithium ion, with Sodium-ion battery is not necessarily suitable as the electrode material for being suitable for lithium ion battery.Wherein, metal selenide is not only both fitted It is suitable for sodium-ion battery again for lithium ion battery, and specific capacity is higher, but there are still conductivities low, opposing metallic sulphur The problem that compound capacity is not good enough.

CN105390674A discloses a kind of two ferrous selenides of sodium-ion battery/sulfur doping graphene anode material and system Preparation Method, the composite material to be dispersed in the three-dimensional that sulfur doping graphene surface constitutes by two selenizing iron nano-particles compound Structure.Compared to two single selenizing iron materials, hence it is evident that improve the high rate performance and stable circulation performance of electrode material, together When, the preparation method provided also effectively prevents the reunite random pattern therefore, especially crystal of two selenizing iron particles The generation of cluster pattern.

Summary of the invention

Technical problem solved by the present invention is overcoming the above deficiency, the present invention provides a kind of dianion cobalt-based selenium vulcanization Object and preparation method thereof.The dianion cobalt-based selenium sulfide is in hollow polyhedral, and surface is uniformly twined by graphene oxide Around forming stable three-dimensional structure, be conducive to the electric conductivity for improving material, hollow structure can be effectively relieved as negative electrode material When charge and discharge process in volume expansion, improve the cyclical stability of negative electrode material.

The technical solution adopted by the present invention to solve the technical problems is:

A kind of dianion cobalt-based selenium sulfide, chemical general formula is Co_0.85Se_1-xS_x@rGO, wherein 0 x≤0.5 <.

Preferably, in the dianion cobalt-based selenium sulfide, Co_0.85Se_1-xS_xIt is the hollow of 200 ~ 400 nm in partial size Polyhedron, and by redox graphene uniform winding.

The preparation method of above-mentioned dianion selenium sulfide uses cobalt salt to react with 2-methylimidazole first and generates forerunner Then presoma and graphene oxide are mixed, so that presoma is attached to surface of graphene oxide, be eventually adding sulphur source and selenium by body Source carries out hydro-thermal reaction, and it is uniform that synchronous realization sulphur source and selenium source form surface layer redox graphene in conjunction with cobalt in presoma The Co of winding, body phase S doping_0.85Se particle.

Preferably, the preparation method comprising the following specific steps

(1) 2-methylimidazole solution is added in Co salting liquid, is stood, is separated by solid-liquid separation, wash solid, dry presoma；

(2) selenium powder is dispersed in solvent I, reducing agent is then added, reaction generates to obtain selenium source solution to bubble-free；

(3) it disperses the presoma and graphene oxide in solvent II and forms suspension, sulphur source solution is added and selenium source is molten Liquid forms reaction solution, is warming up to 150 ~ 200 DEG C, reacts 4 ~ 30h.

Preferably, the solvent of the 2-methylimidazole solution is selected from one of pure water, methanol, ethyl alcohol and ethylene glycol or more Kind, the solvent of the cobalt salt solution is selected from one of pure water, methanol, ethyl alcohol and ethylene glycol or a variety of.

Preferably, the mass ratio of the material of element sulphur and selenium powder is 0.1 ~ 4 in the sulphur source；More preferably, the sulphur source The mass ratio of the material of middle element sulphur and selenium powder is 1 ~ 3.

Preferably, in the presoma in the amount and sulphur source of the substance of Co element in element sulphur and selenium powder selenium element substance The sum of amount be 1:1 ~ 10.

Preferably, the mass ratio of the graphene and presoma is 1:5 ~ 30, it is preferred that the graphene and presoma Mass ratio is 1:8 ~ 15.

Preferably, in the suspension, the concentration of presoma is 1-10 mg/L.

Preferably, the concentration of the sulphur source solution is 0.05 ~ 0.5mol/L.

Preferably, the sulphur source is selected from one of thioacetamide, vulcanized sodium and ammonium sulfide or a variety of.

Preferably, the solvent in the sulphur source solution and solvent II are selected from one in pure water, ethyl alcohol, ethylene glycol and methanol Kind is a variety of；Preferably, the solvent I is water or ethyl alcohol；More preferably, the solvent of the sulphur source solution and solvent II are Water, the solvent I are ethyl alcohol.

Preferably, 1 ~ 4:1 of the mass ratio of the material of the reducing agent and selenium powder；Preferably, the reducing agent is sodium borohydride Or hydrazine hydrate.

Preferably, the concentration of selenium element is 0.01 ~ 0.5mol/L in the selenium source solution.

Preferably, the temperature that the selenium powder is reacted with reducing agent is -10 ~ 10 DEG C.

Preferably, the cobalt salt selected from cobaltous sulfate, cobalt nitrate, cobalt chloride and cobalt acetate and four hydrate in one Kind is a variety of.

Preferably, the mass ratio of the material of cobalt element and 2-methylimidazole is 0.01 ~ 0.35:1 in the cobalt salt, it is preferred that The mass ratio of the material of cobalt element and 2-methylimidazole is 0.2:1 in the cobalt salt.

Preferably, the concentration of the cobalt salt solution is 0.01 ~ 0.15mol/L.

Preferably, the time of the standing is 10 ~ 30h.

Preferably, in the step (3), 180 DEG C of the temperature of the reaction；Preferably, the time of the reaction be 14 ~ 16h。

The beneficial effects of the present invention are:

(1) dianion cobalt-based selenium sulfide of the present invention is in hollow polyhedral, and surface is formed by graphene oxide uniform winding Stable three-dimensional structure, is conducive to the electric conductivity for improving material, and hollow structure fills when can be effectively relieved as negative electrode material Volume expansion in discharge process improves the cyclical stability of such material；

(2) preparation method of the present invention uses cobalt salt and 2-methylimidazole to form organic metal framework specific morphology first, is made with this For subsequent cobalt source and template, one step hydro thermal method is then utilized, by regulation reaction condition to maintain specific morphology, utilizes Ke Kenda Your effect designs core-shell structure, synchronous cladding, the doping of S and the shape of hollow polyhedral pattern for realizing redox graphene At, so that hollow polyhedral of the dianion cobalt-based sulfide of preparation in rule, and then improve its electricity as negative electrode material Chemical property.

Detailed description of the invention

Fig. 1 is the XRD diagram of dianion cobalt-based selenium sulfide prepared by the embodiment of the present invention 1；

Fig. 2 is the SEM figure of dianion cobalt-based selenium sulfide prepared by the embodiment of the present invention 1；

Fig. 3 is the TEM figure of dianion cobalt-based selenium sulfide prepared by the embodiment of the present invention 1；

Fig. 4 is the SEM figure of dianion cobalt-based selenium sulfide prepared by the embodiment of the present invention 2；

Fig. 5 is the TEM figure of dianion cobalt-based selenium sulfide prepared by the embodiment of the present invention 2；Fig. 6 is that the embodiment of the present invention 2 is made The cycle performance figure of standby dianion cobalt-based selenium sulfide；

Fig. 7 is the SEM figure of dianion cobalt-based selenium sulphur compound prepared by comparison example 1.

Specific embodiment

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