[1]This application claims the benefit of priority based on the June 8, 2016 Korea Patent Application No. 10-2016-0071216, and all information disclosed in the literature of the Korea patent application is included as part of the specification.
[2]
The present invention relates to a self-assembled complex of the carbon nitride with graphene oxide, and more particularly, melamine (Melamine), tree thio when isocyanurate acid (Tri-thiocyanuric acid) and graphene oxide (Graphene oxide: GO) is dissolved a self-assembled complex produced by heat treating the mixture of lithium-sulfur battery by including a positive electrode is intended to suppress the elution of lithium polysulfide.
[3]
BACKGROUND
[4]
Recent electronic products, electronic devices, the small and light proceeds rapidly, such as communication equipment, and also increased demand for improved performance of the secondary battery to be in connection with environmental issues used as a power source for these products, as there is a need for an electric vehicle greatly soybean a situation which. Among them, the lithium secondary battery has received considerable attention as a high-performance battery, because a high energy density and a high standard electrode potential.
[5]
[6]
In particular, a lithium-sulfur (Li-S) cells SS bond is a secondary battery using a sulfur-based material having a (Sulfur sulfur bond) as the positive electrode active material, a lithium metal as an anode active material. There is a main material of the positive electrode active material, the sulfur resource is very rich, and toxicity, it is advantageous to have a low weight per atom. In addition, the lithium-sulfur battery of the theoretical discharge capacity was 1675mAh / g-sulfur, and the theoretical energy density as 2,600Wh / kg, theoretical energy density of the other battery systems that are currently studies (Ni-MH cells: 450Wh / kg, Li- FeS cell: 480Wh / kg, Li-MnO 2 cells: 1,000Wh / kg, Na-S cells: due to the very high compared to 800Wh / kg) is the most promising from the battery cell that is being developed.
[7]
[8]
Lithium-oxidation reaction of lithium occurs in the negative electrode during the discharge reaction of the sulfur battery (Anode) and cathode (Cathode) The generated sulfur reduction. S of the annular sulfur before the discharge 8 I have a structure, reduction (discharge) the oxidation of SS bonds are broken As reduces the oxidation number of S, and as the oxidation (charge) when SS bond is formed again, increases the oxidation state of the S - by a reduction reaction to store and produce electrical energy. This reaction of the sulfur S of the ring-shaped 8- lithium polysulfide (Lithium polysulfide, Li linear structure by a reduction in reaction 2 S x will be converted to, x = 8, 6, 4 , 2), eventually the lithium polysulfide completely When the reduction finally lithium sulfide (lithium sulfide, Li 2 is to be generated S). By the process of reduction in the respective lithium polysulfide, lithium-sulfur battery of the discharge behavior is characterized by showing a staged discharge voltage in contrast to the lithium ion battery.
[9]
[10]
Li 2 S 8 , Li 2 S 6 , Li 2 S 4 , Li 2 S 2 lithium polysulfide in, in particular lithium Poly the sulfur oxidation number higher sulfide such as (Li 2 S x , usually x> 4) is the hydrophilic electrolyte easily soluble. Molten lithium in the electrolytic solution polysulfide goes diffuses away from the lithium polysulfides is produced by the positive difference density. The thus eluted from the positive electrode of lithium poly sulfide is lost out of the anode reaction zone of lithium sulfide (Li 2 it is impossible to gradually reduced to S). That is, since the anode and the cathode to beyond that present in the dissolved state lithium polysulfide will not be able to participate in the charge and discharge reaction of the battery, the amount of the sulfur material to participate in the electrochemical reaction is decreased in the positive electrode, after the lithium-sulfur It is a major factor causing the charge capacity of the battery decreases and energy reduction.
[11]
[12]
As well as a lithium polysulfides diffuse to the cathode include Li on the negative electrode surface, by direct reaction with the lithium addition to be suspended or precipitated in the electrolyte solution 2 to generate a problem of corrosion of lithium metal cathode, so fixed in the S form.
[13]
[14]
In order to minimize the dissolution of the lithium polysulfide, a study is underway to transform the morphology (Morphology) of different carbon anode structure and the composite to form the composite supported by the sulfur particles in the metal oxide (Metal oxide).
[15]
[16]
Among them is a lithium polysulfide, adsorption due to the change in surface polarity (Polarity) For the carbon material in which nitrogen is doped, one of several nitrogen-functional groups doped in the carbon surface, blood rolgi (Pyrrolic group) and the pyridine group (Pyridinic group) is has been reported to exhibit an effect in the adsorption of lithium polysulfide (Chem Mater., 2015, 27, 2048 / Adv. Funct. Mater., 2014, 24, 1243).
[17]
[18]
In particular, carbon nitride (C 3 N 4 , Carbon nitride: CN) while being arranged in a carbon-nitrogen alternately as two won compound having the structure is hexagonal rings expanded in two dimensions, there is a large amount containing a beneficial pyridine lithium polysulfide adsorption lithium-known that they can inhibit the dissolution of a lithium polysulfide that is a problem in sulfur battery (Nano Lett, 2015, 15, 5137.). The carbon nitride may generally be synthesized by heat treating the nitrogen precursor, such as urea, dicyandiamide, melamine. However, the carbon nitride is 10 -11 due to the low conductivity of the S / m, by itself is a situation where the limit to serve as the electrode material of the battery.
[19]
[20]
[Prior art document]
[21]
Republic of Korea Patent Application No. 1347789 No. "carbon fluoride nitro (C3N4) - graphene composite production method and hence the carbon fluoride prepared by Knight (C3N4) - graphene composite"
[22]
Detailed Description of the Invention
SUMMARY
[23]
As described above, the lithium-sulfur cells slows due to lithium polysulfide that diffusion is eluted from the positive electrode proceeds, the charging and discharging cycles, there is a problem that the capacity and life characteristics of the battery decreases. The present inventors have found that lithium as the positive electrode material of a sulfur battery, a large amount of pyridine group (Pyridinic group) showing the performance in the adsorption of lithium polysulfide, and the conductivity is improved carbon nitride-graphene oxide (Carbon nitride-Graphene oxide ) complex was to develop a.
[24]
It is therefore an object of the present invention is eluted and diffused in the inhibiting lithium lithium polysulfide-to provide a sulfur battery.
[25]
Problem solving means
[26]
In order to achieve the above object, the present invention is a melamine (Melamine), tree thio when isocyanurate acid (Tri-thiocyanuric acid) and graphene oxide (Graphene oxide), carbon nitride (CN) is prepared by heating the soluble mixed solution So as to provide a method of manufacturing a self-assembled complex (self-assembled composite) of the pin-oxide (GO).
[27]
In another aspect, the present invention provides a self-assembled complex (Self-assembled composite) of a carbon nitride (CN) and the graphene oxide (GO) produced by the above production method.
[28]
In another aspect, the present invention is a carbon nitride (CN) and the graphene lithium containing a self-assembling composite (Self-assembled composite) of oxide (GO) produced by the above production method-sulfur battery-sulfur battery, the positive electrode and lithium-containing them to provide.
[29]
Effects of the Invention
[30]
According to the invention, the pyridine group (Pyridinic group) a large amount, and carbon nitride, the conductivity is improved (CN) and yes from self-assembled complex (Self-assembled composite) that during the charge and discharge the anode of the pin oxide (GO) it is possible to improve the sulfur battery capacity and service life characteristics - by adsorbing the eluted lithium polysulfide that it serves to prevent the diffusion, to suppress the reaction of lithium shuttle.
[31]
Brief Description of the Drawings
[32]
Figure 1 is a scanning electron microscope image of the magnetic assembly of the melamine, triethylene thio when isocyanurate acid and graphene oxide according to the first embodiment of the present invention.
[33]
Figure 2 is a scanning electron microscope image of a GO / CN self-assembled complex produced by heating the self-assembled complex of melamine, triethylene thio when isocyanurate acid and graphene oxide according to the first embodiment of the present invention.
[34]
Figure 3 is a scanning electron microscope image of a S- (GO / CN) complex according to the second embodiment of the present invention.
[35]
Figure 4 is a scanning electron microscope image of a self-assembled body of the melamine and the Tree thio when isocyanurate acid according to Comparative Example 1 of the present invention.
[36]
Figure 5 is a scanning electron microscope image of the fluoride prepared by heating the self-assembled product of melamine and isocyanurate during tree thio acid according to Comparative Example 1 of the present invention the carbon night.
[37]
6 is an XPS spectrum of the carbon fluoride night according to a comparative example 1 of the present invention.
[38]
7 is an XPS spectrum of the GO / CN self-assembled complex according to the first embodiment of the present invention.
[39]
8 is a powder resistance data of GO / CN complex of the self-assembled self-assembled complex according to the first embodiment of the present invention.
[40]
9 is lithium according to the Preparation Example 1 of the present invention is the data showing the discharge capacity of the sulfur battery.
[41]
Figure 10 is a lithium according to Preparation Example 2 of the present invention is the data showing the discharge capacity of the sulfur battery.
[42]
Figure 11 is a lithium according to Preparation Example 3 of the present invention is the data showing the discharge capacity of the sulfur battery.
[43]
12 is prepared in Example 1, 2, and lithium in accordance with the third of the present invention is the data showing the cycle life characteristics of the sulfur battery and charge and discharge efficiency.
[44]
Figure 13 is a lithium according to Preparation Example 4 of the present invention - is the data showing the discharge capacity of the sulfur battery.
[45]
14 is prepared according to Example 4 of the present invention lithium-is data showing the cycle life characteristics of the sulfur battery and charge and discharge efficiency.
[46]
Best Mode for Carrying Out the Invention
[47]
Will be described below in detail on the basis of the accompanying drawings illustrate a preferred embodiment of the present invention. This figure may be implemented in many different forms one embodiment for explaining the present invention, and is not limited herein. At this point in the figure it was not a part not related to the description in order to clearly describe the present invention, the like reference numerals used for similar parts throughout the specification. Also, the size and relative sizes of the components shown in the figures may be reduced or exaggerated for clarity of illustration, and are independent from the actual scale.
[48]
[49]
In the present invention, self-assembly and the conditions combined by melamine and the Tree thio when isocyanurate acid (or here.Well by the addition of pins oxide to) without the chemical reaction in the precursor state, electrostatic attraction, while self-assembling complexes melamine, triethylene thio when isocyanurate acid and graphene oxide is due to a heat treatment causing the chemical reaction to form a carbon nitride by yes means that the composite oxide and the pin.
[50]
[51]
The invention carbon nitride: by selecting the method of heat treatment of the melamine (Melamine) and tree thio when isocyanurate acid (Tri-thiocyanuric acid) as a precursor in the synthesis method of (Carbon nitride CN), to give the conductivity in the mixing process, so it added the pin oxide (Graphene oxide) that was prepared by the self-assembled complex (self-assembled composite), the positive electrode and the lithium is thus improved conductivity material applied - presents a sulfur battery.
[52]
[53]
A carbon nitride (CN) and yes self-assembled complex (the GO / CN self-assembling complexes) of the pin-oxide (GO) is because there is yes the electron transporting ability of the fluoride carbon nitro pin oxide can compensate, the carbon nitride e it is possible to improve the catalytic activity for the transmission.
[54]
[55]
According to the invention, GO / CN self-assembled complex is a precursor material with graphene oxide, the carbon fluoride nitro may be prepared by heating a dissolved mixture. At this time, as the precursor material of the carbon nitride, it is preferred to apply the melamine (Melamine), thio tree when isocyanurate acid (Tri-thiocyanuric acid).
[56]
[57]
Dimethyl melamine and the Tree thio when isocyanurate acid sulfoxide (Dimethyl sulfoxide: DMSO) were dissolved in a solvent when added to water to form the magnetic assembly. This is coupled with the magnetic assembly and melamine isocyanurate tree thio when Rick acid hydrogen bonding and electrostatic attraction to form a, also be stacked (Stacking) through π-π interaction (π-π Interaction). These melamine and the Tree thio upon self assembly of the isocyanurate acid helium (He), nitrogen (N 2 in), argon (Ar), neon 400 to 700 ℃ in an inert gas atmosphere, such as (Ne) or xenon (Xe) 1 to When the heat treatment for 10 hours, thereby forming the carbon nitride of the shoe-box.
[58]
[59]
Using the above-described melamine and the Tree thio when the magnetic assembly to form the principles of the isocyanurate acid, it was dissolved melamine and the Tree thio when isocyanurate acid in DMSO, the graphene oxide dissolved in water: The mixture of (Graphene oxide GO), Fig. forming a self-assembly as shown in Figure 3, and since in the above in the same manner as described for the inert gas atmosphere when the heat treatment for 1 to 10 hours at 400 to 700 ℃, the nanotube type GO / CN a self-assembled complex It can be formed.
[60]
[61]
More specifically, melamine, tri thio when isocyanurate acid and yes melamine and the Tree thio when isocyanurate rigs acid molar content ratio at which the pin oxide dissolved mixed solution is 2: 1 to 1: 2 is one of the most preferable to form the magnetic assembly, the do not limit it in the invention. In addition, it is preferred to add an excess amount than the graphene oxide in the mixed solution, but is added in 0.1 to 90% by weight based on the weight of the range of the melamine and the Tree thio when isocyanurate acid, to configure in the GO / CN self-assembling composite. This is because forming the GO / CN self-assembled complex in the washing and filtering process of removing the solvent and remaining graphene oxide leakage. The prepared GO / CN amount of magnetic oxide on the graphene composite assembly may be contained in GO / CN 1 to 50% by weight of the self-assembled complex overall weight.
[62]
[63]
Lithium-sulfur battery, the positive electrode
[64]
Day GO / CN magnetic suggested in an embodiment of the foregoing complex is assembled lithium may be used in the use of sulfur as a simple mixture used for the positive electrode active material of sulfur battery, or complexed form. The GO / CN self-assembled complex is adsorbed a lithium polysulfide, it can consequently increase the discharge capacity, and improve the over-voltage characteristics. Further, it showed excellent discharge capacity retention rate, and a long period of time maintaining high capacity even after cycles. In particular, the composite type GO / CN magnetic case can be a structure coated on the surface of the composite assembly as sulfur, to the contact area between the sulfur to increase the absorption polysulfide more effectively.
[65]
[66]
The anode is a sulfur-based material as a positive electrode active material may include a sulfur element (Elemental sulfur, S8), a sulfur-based compound, or a mixture thereof, which is applicable in combination with a conductive material. The sulfur-based compound is particularly, Li 2 S n (n≥1), an organic sulfur compound or a carbon-sulfur polymer ((C 2 S x ) n : and the like x = 2.5 ~ 50, n≥2) .
[67]
[68]
The challenge may be a porous material. Therefore, as long as the conductive material having a porosity and conductivity can be used without limitation, and for example may be a carbonaceous material having a porosity. Such a carbon-based material may be used carbon black, graphite, graphene, carbon, carbon fibers, carbon nanotubes (CNT) or the like. In addition, a metallic fiber, such as a metal mesh; Copper, silver, metallic powders of nickel, aluminum and the like; Or polyester may also be used organic conductive materials such as polyphenylene derivatives. The conductive materials may be used alone or in combination.
[69]
[70]
In one embodiment, the GO / CN self-mixing a positive electrode material containing a composite assembly to prepare a slurry, or, in another embodiment, the GO / CN self-assembly complex sulfur-based material and the S- (GO / CN) conjugate forming a post, it can be prepared as a slurry. The GO / CN self-assembled composite, a sulfur-based material and has a conductive material may be applied to a mixture mixed at a predetermined mixing ratio, preferably GO / CN self-assembly complex comprises from 0.5 to 50 wt% of the positive electrode material weight it is preferable because it can secure the positive electrode active material in the sulfur content to a level more than that.
[71]
[72]
Coating the anode slurry on a current collector and vacuum-dried lithium-sulfur battery, the positive electrode can be formed. The slurry may be coated on the current collector to an appropriate thickness according to the thickness of the positive electrode and that the viscosity of the slurry to be formed and, preferably, can be appropriately selected within a range of 10nm to 1㎛.
[73]
[74]
At this time, a method of coating the slurry that the restriction is not, for example, doctor blade coating (Doctor blade coating), dip coating (Dip coating), gravure coating (Gravure coating), a slit die coating (Slit die coating), spin coating ( Spin coating), it can be produced by performing such as comma coating (comma coating), bar coating (bar coating), a reverse roll coating (reverse roll coating), screen coating (screen coating), the cap coating (cap coating) method.
[75]
[76]
To the current collector is generally can be made to have a thickness of 3 ~ 500㎛, without causing chemical changes in the battery if it has a high electrical conductivity is not particularly limited. Specifically, it is possible to use a conductive material such as stainless steel, aluminum, copper, titanium, more specifically, carbon-coated aluminum can be used the whole house. It was to use the aluminum substrate having the carbon coating has excellent adhesion to the active material, compared to a non-carbon-coated, and the lower the contact resistance, there is an advantage capable of preventing corrosion by a polysulfide of aluminum. Collector can be in various forms such as films, sheets, foils, nets, porous structures, foams, or nonwoven material.
[77]
[78]
A lithium-sulfur battery
[79]
The lithium-sulfur battery, the positive electrode; A negative electrode comprising a lithium metal or a lithium alloy as a negative electrode active material; A separator positioned between the positive electrode and the negative electrode; And which is impregnated in the negative electrode, positive electrode and separator may include an electrolyte comprising a lithium salt and an organic solvent.
[80]
[81]
The negative electrode is a negative electrode active material a lithium ion (Li + ) for reversibly storing (Intercalation) a release-to (Deintercalation) reactants, a lithium ion and that can be a substance capable of forming a lithium-containing compound by reversibly, lithium metal or lithium You can use an alloy. The lithium ion (Li + material capable of reversibly storing or discharging a) may be, for example, crystalline carbon, amorphous carbon, or a mixture thereof. The lithium ion (Li + material capable of forming a reversible lithium-containing compound to react with a) may be, for example, tin oxide, titanium nitrate or a silicone. The lithium alloy is, for example, lithium (Li) and sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), Francium (Fr), beryllium (Be), magnesium (Mg), calcium ( Ca), may be a strontium (Sr), barium (Ba), radium (Ra), aluminum (Al), silicon (alloy of a metal selected from the group consisting of Si) and tin (Sn).
[82]
[83]
Further, a lithium-sulfur in the course of charging and discharging the battery, sulfur is used as the cathode active material changes to the inactive material, it can be attached to the lithium anode surface. As such inert sulfur (Inactive sulfur) is sulfur various electrochemical or chemical reaction via the means any more of that can not participate state sulfur electrochemical reaction of the positive electrode, and an inert sulfur protective layer of the lithium negative electrode formed on the lithium anode surface (Protective layer ) has the advantage that acts as a.
[84]
[85]
Between the anode and the cathode has the conventional separation membrane can be interposed. The separator is a physical separation membrane has a function of separating the electrodes physically, so long as it is used in a conventional membrane can be used without particular limitation, and is especially low in resistance, yet preferably excellent in electrolytic solution humidification ability against ion mobility of the electrolyte solution.
[86]
[87]
Further, the separator makes it possible to transport of lithium ions between the positive electrode and the negative electrode, while separated from each other or insulated to the positive electrode and the negative electrode. This membrane is porous and may be made of a non-conductive or insulative material. The membrane may be either an independent member such as a film, or the anode and / or cathode in addition to the coating layer.
[88]
[89]
Specifically, the sole of a porous polymer film, such as ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ethylene / hexene copolymers and ethylene / meta produced by the polyolefin-based polymers such as methacrylate copolymer porous polymer film It can or laminated them are used or conventional porous nonwoven fabric, such as high, but can use the non-woven fabric of glass fiber, polyethylene terephthalate fiber, such as the melting point, and the like.
[90]
[91]
Electrolyte which is impregnated in the positive electrode, negative electrode and separator is a non-aqueous electrolyte containing a lithium salt consists of a lithium salt and an electrolytic solution, such as an organic solid electrolyte and inorganic solid electrolyte may be used in addition.
[92]
[93]
The lithium salt of the present invention is a material that is readily soluble in non-aqueous organic solvent, for example, LiCl, LiBr, LiI, LiClO 4 , LiBF 4 , LiB 10 Cl 10 , LiB (Ph) 4 , LiPF 6 , LiCF 3 SO 3 , LiCF 3 CO 2 , LiAsF 6 , LiSbF 6 , LiAlCl 4 , LiSO 3 CH 3 , LiSO 3 CF 3 , LiSCN, LiC (CF 3 SO 2 ) 3 , LiN (CF 3 SO 2 ) 2 , LiNO 3 , chloroborane lithium , it may include a lower aliphatic carboxylic acid lithium, lithium tetraphenyl borate, lithium already one or more from the group consisting of draw.
[94]
[95]
The concentration of the lithium salt is, depending on the exact composition of the electrolyte mixture, salt solubility, dissolved salt conductivity, the battery charge and discharge conditions, the operation temperature and the lithium number of factors, such as other factors known in the battery field, 0.2 ~ 4M, specifically with 0.3 ~ 2M, 0.3 ~ 1.5M may be more specific. When used with less than 0.2M lowers the conductivity of the electrolyte and the electrolyte performance may be poor, when used in excess of 4M lithium ion (Li by the viscosity of the electrolyte increases + can be a mobility of a) reduction.
[96]
[97]
In the non-aqueous organic solvent and the need to dissolve a lithium salt, a non-aqueous organic solvent of the present invention is, for example, diethylene glycol dimethyl ether, N- methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, gamma-butyrolactone, 1,2-dimethoxyethane, 1,2-diethoxy ethane, tetrahydroxy Franc (franc), 2- methyl tetrahydrofuran, dimethyl sulfoxide, 1,3-dioxolane, 4-methyl-1,3-oksen, diethylether, formamide, dimethylformamide, acetonitrile, nitromethane, methyl formate, methyl acetate, phosphoric acid triester, tri- trimethoxy methane, dioxolane derivatives, sulfolane, and methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbonate derivatives, tetrahydrofuran derivatives, ether, methyl propionate, ethyl propionate Biyang and magnetic can be used an organic solvent, the organic solvent may be one or a mixture of two or more organic solvents.
[98]
[99]
As the organic solid electrolyte, for example, polyethylene derivatives, polyethylene oxide derivatives, polypropylene oxide derivatives, phosphoric acid ester polymers, poly-edge presentation lysine (Agitation lysine), polyester sulfide, polyvinyl alcohol, polyvinylidene fluoride, an ionic dissociation the polymers containing groups may be used.
[100]
[101]
An inorganic solid electrolyte of the present invention is, for example, Li 3 N, LiI, Li 5 NI 2 , Li 3 N-LiI-LiOH, LiSiO 4 , LiSiO 4 -LiI-LiOH, Li 2 SiS 3 , Li 4 SiO 4 , Li 4 SiO 4 -LiI-LiOH, Li 3 PO 4 -Li 2 S-SiS 2 has a nitride, halide, sulfate of Li such as such can be used.
[102]
[103]
In order to improve the electrolyte of the present invention, the charging and discharging characteristics and flame retardancy, for example, pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylenediamine, n- glyme (glyme), hexamethyl phosphoric acid amide tree, a nitro this may be added to benzene derivatives, sulfur, quinone imine dyes, N- substituted oxazolidinone, N, N- substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salts, pyrrole, 2-methoxy ethanol, aluminum trichloride . In some cases, in order to provide a non-flammable, it is also possible to further include a halogen-containing solvent such as carbon tetrachloride, ethylene trifluoride, and also possible to further include a dioxide carbon dioxide gas to improve high temperature storage characteristics, FEC (Fluoro-ethylene and the like carbonate), PRS (Propene sultone), FPC (Fluoro-propylene carbonate) can be further included.
[104]
[105]
By laminating between one cut of the above-described positive electrode and the negative electrode to the positive electrode plate and negative electrode plate to a predetermined size through a membrane cut to a predetermined size corresponding to the positive electrode plate and negative electrode plate it can be manufactured in a stack type electrode assembly.
[106]
[107]
Or the positive and negative electrodes, but via so as to face sandwiching the separator sheet, the two or more two or more positive electrode plates and the arrangement of the negative electrode plate on the separator sheet, or at least the two positive and negative plates are units which are stacked across the membrane cells by arranging for the separator sheet, and winding the separator sheet, the separator sheet bent to the size of the electrode plate, or the unit cell stack, and it is possible to manufacture a the folding type electrode assembly.
[108]
Mode for the Invention
[109]
Will be described below in detail on the basis of the accompanying drawings illustrate a preferred embodiment of the present invention. This figure may be implemented in many different forms one embodiment for explaining the present invention, and is not limited herein. At this point in the figure it was not a part not related to the description in order to clearly describe the present invention, the like reference numerals used for similar parts throughout the specification. Also, the size and relative sizes of the components shown in the figures may be reduced or exaggerated for clarity of illustration, and are independent from the actual scale.
[110]
[111]
GO / CN self-assembled complexes produced
[112]
It was dissolved in the melamine (Melamine) 2mmol in DMSO of 10mL, where 2% graphene oxide aqueous solution of 2g was added (Graphene oxide) in, and here the tree thio when isocyanurate acid (Tri-thiocyanuric acid) The dimethyl sulfoxide was dissolved 2mmol (DMSO) followed by the addition of 5mL solution, by the addition of 15mL of distilled water in order to prepare a self-assembly. Then, after the above prepared magnetic assembly was washed with water three times to obtain dried overnight in a vacuum oven at 110 ℃ (shown in Figure 1).
[113]
[114]
It is the obtained gives flowing Ar gas to the magnetic assembly 550 ℃ by heating for 4 hours, the diameter and length of 200nm ~ 1㎛ 2㎛ ~ 10㎛ of the hollow tube (Tube) GO / CN self-assembling complexes of the type that was formed (shown in Figure 2). To take a sample of the GO / CN self-assembled complexes produced BET analysis 43m 2 has a specific surface area / g, 0.49cm 3 appeared to have the void volume (Pore volume) of / g.
[115]
[116]
S- (GO / CN) complexes prepared
[117]
For the embodiment to composite a production GO / CN self-assembly complex and sulfur particles in the example 1, S in a way that the sulfur melt-diffusion at 155 ℃: the weight ratio of (GO / CN) 7: such that the 3 GO / CN supported by the sulfur in the self-assembly complex was prepared S- (GO / CN) complex (shown in FIG. 3). As a result GO / CN are surface sulfur coated S- (GO / CN) of the complex self-assembly complex was formed.
[118]
[119]
Preparation of carbon nitride (CN)
[120]
Dissolved in the melamine (Melamine) and thio tree when isocyanurate acid (Tri-thiocyanuric acid) to each respective 20mL and 10mL of dimethylsulfoxide (DMSO) solvent by taking 4mmol, then a solution of 30mL of water was added to it to prepare a self-assembly. Was then obtained by washing and drying in the same manner as in Example 1 (shown in FIG. 4).
[121]
[122]
Since in Example 1 and subjected to heat treatment in the same manner was the carbon nitride (CN) particles of a shoe-box of about 1㎛ x 5㎛ size formed (shown in Fig. 5).
[123]
[124]
lithium-sulfur battery manufactured
[125]
The ratio of CMC / SBR 80:: S / Super-P (9: 1): Denka black (Denka black) 10: 10 to prepare a slurry. Using the thus prepared slurry 2mAh / cm 2 was coated with the positive electrode slurry having a loading on an aluminum (Al) foil. Using this positive electrode, CR2032 coin cell (Coin cell) DEGDME the type: DOL = 6: 4, 1 M LiFSI, 1% LiNO 3 with the electrolyte solution of the composition of the lithium-sulfur battery was fabricated. (However, CMC is Carboxymethyl cellulose, SBR is a Styrene-butadiene rubber, DEGDME is Diethylene glycol dimethyl ether, DOL is Dioxolane, LiFSI is Lithium bis (fluorosulfonyl) imide.)
[126]
[127]
lithium-sulfur battery manufactured
[128]
The ratio of CMC / SBR 80:: Comparative Example 1 to apply the produced carbon nitride (CN) as a cathode additive in, S / Super-P (9: 1): Denka black (Denka black): CN 10: to prepare a slurry to be 5: 5. To do this with a slurry of lithium in the same manner as Preparation Example 1 to prepare a sulfur battery.
[129]
[130]
lithium-sulfur battery manufactured
[131]
Carried out to apply the GO / CN self-assembled complex produced in Example 1 as a cathode additive, S / SuperP (9: 1): Denka black (Denka black): GO / CN self-assembling complexes: the ratio of CMC / SBR 80 : to prepare a slurry to be 5: 10: 5. To do this with a slurry of lithium in the same manner as Preparation Example 1 to prepare a sulfur battery.
[132]
[133]
lithium-sulfur battery manufactured
[134]
In order to apply the S- (GO / CN) complex prepared in Example 2 as a cathode active material, S- (GO / CN) complex: Denka black (Denka black): the ratio of CMC / SBR 90: 5: 5 are so that the electrode to prepare a slurry, and lithium in the same manner as Preparation example 1 to prepare a sulfur battery.
[135]
[136]
<실험예 1> XPS(X-ray Photoelectron Spectroscopy) 실시
[137]
By performing a first embodiment of the GO / CN self-assembled complexes as in Comparative Example Carbon samples the XPS (X-ray Photoelectron Spectroscopy) fluoride nitro one prepared above, were analyzed for C 1s and N 1s spectra and the surface element.
[138]
[139]
First, as FIG. 6, when the reference to the data of Figure 7 carbon nitride of Comparative Example 1 in the C 1s and N 1s spectra identified in Fig. 6, it has been difficult to measure the exact Charging effect. However, Example 1 GO / CN CNC pyridinic N is large amount of self-assembled complex of which was confirmed by the Figure 7 that the effect Charging hayeoteum significantly reduced. This embodiment GO / CN self-assembled complex of Example 1 was confirmed through the yes pin hayeoteum increase the conductivity by the oxide.
[140]
[141]
In addition to the surface of the elemental analysis results are shown in Table 1 below.
[142]
TABLE 1
% C N O S CN
Example 1 43.8 55.2 0.9 0.1 0.79
Comparative Example 1 41.4 58.0 0.6 0 0.71

[143]
[144]
Inde Theoretical C / N ratio of Graphitic carbon nitride 0.75, and is generally the hydrogen of the terminal group bonded to and 0.72 to see, when the Referring to Table 1, synthesized according to Example 1 GO / CN self-assembled complex the 0.79, 0.71 in Comparative example 1. the carbon fluoride nitro synthesized according to (CN) was measured.
[145]
[146]
Powder Resistance
[147]
The powder resistance of the first embodiment of the GO / CN carbon nitro Comparative Example 1 of the magnetic assembly and the complex fluoride was measured. Comparing the carbon nitride of the first embodiment has a resistance of 10 7 to Ω · GO / CN self-assembled complex of when, but very high above cm difficult to obtain a measured value, see the data of Figure 8, the first embodiment reduces the resistance, when it has a density (density) of 1.04g / cc the powder resistance 1.13 x 10 2 was measured in Ω · cm.
[148]
[149]
discharge amount measurement
[150]
Preparation Examples 1 to 3 produced in the lithium-With reference to the discharging capacity was measured characteristics of the sulfur battery (0.1C / 0.1C), as a result, 9 to 11, the addition of carbon nitride as compared to Production Example 1 in the case of Preparation example 2 was the discharge capacity is increased as a whole, it was confirmed that a GO / CN self-assembly in a complex preparation 3 was added to the discharge voltage slightly lower than that in Production example 1 as a whole.
[151]
[152]
cycle life characteristics and charge and discharge efficiency test
[153]
Preparation Examples 1 to 3 produced in the lithium-sulfur battery was characteristic of the cycle life (0.1C / 0.1C at 2.5 cycle after the charge and discharge to 0.3C / 0.5C) and measuring the charge and discharge efficiency characteristics, and as a result, FIG. Referring to 12, was the carbon Preparation 2 and charge and discharge of preparation 3, the efficiency with the nitride is greatly improved as compared with Production example 1, in particular GO / CN cycle characteristics even in Preparation example 3 was added to the self-assembled complex improved.
[154]
[155]
discharge amount measurement
[156]
The lithium produced in Production Example 4 - were measured for discharge capacity characteristic of sulfur battery (0.1C / 0.1C), as a result, when the comparison reference to Figure 13 and Figure 9, the initial discharge capacity was almost the same as in Preparation Example 1, the cycle proceeds during the discharge capacity as compared to Production example 1 was increased as a whole.
[157]
[158]
cycle life characteristics and charge and discharge efficiency test
[159]
The lithium produced in Production Example 4 - were measured and the cycle life characteristics (0.1C / 0.1C at 2.5 cycle after charging with 0.3C / 0.5C and discharge) the charge and discharge efficiency of sulfur batteries, in Figure 14 the result It is shown. In Production Example 3 GO / CN magnetic lithium producing the S- (GO / CN) complex prepared in Example 4, the composite assembly than was used as a cathode additive in the positive electrode active material, the capacity retention rate of the sulfur battery excellent, and charge and discharge efficiency could also see that stable.
[160]
[161]
These results are due to more glass on hayeotgi sulfur and GO / CN lithium polysulfide adsorbed by the contact area is increased when the self-assembled complex of a sulfur and a composite S- (GO / CN) complex used than was used as a positive electrode additive It is interpreted.
[162]
Industrial Applicability
[163]
Li accordance with the present invention, because they reliably receive the sulfur battery has excellent discharge capacity and output characteristics and capacity retention rate, cell phones, handheld devices, and hybrid electric vehicles, such as a laptop computer, a digital camera (Hybrid electric vehicle: HEV), etc. it is useful for the electric car sector.
[164]
Accordingly, according to the implementation of another embodiment of the invention, the lithium battery pack including the battery module, and it comprises a sulfur battery unit cell is an electric vehicle (Electric Vehicle, EV), hybrid electric vehicles (Hybrid Electric Vehicle, HEV ), the plug-in may be used in a variety of power supplies, such as hybrid electric vehicles (plug-in hybrid electric Vehicle, PHEV), electric power storage device.

Claims

[Claim 1]Was prepared by heating the carbon nitride precursor and the graphene oxide dissolved in a mixture, method for producing the carbon nitride precursor, melamine and the Tree thio when graphene oxide / carbon nitride self-assembling complexes, characterized in that isocyanurate rigs acid.
[Claim 2]
The method of claim 1, wherein the carbon nitride precursor is a molar ratio of isocyanurate acid when thio melamine and the Tree 2: Preparation of graphene oxide / carbon nitride self-assembling complexes, characterized in that to manufacture such that the 2: 1 to 1 .
[Claim 3]
The method of claim 1, wherein the mixture during manufacturing, the solvent method of producing a dimethyl sulfoxide with graphene oxide, characterized in that a mixed solvent of water / carbon nitride self-assembling composite.
[Claim 4]
In the dimethyl sulfoxide and water is 2 to claim 3 wherein: production method 2 of graphene oxide / carbon nitride self-assembled complex characterized in that the mixture in a weight ratio of 1 to 1.
[Claim 5]
The method of claim 1, wherein the mixture prepared when, dissolved in the melamine and the Tree thio when isocyanurate rigs acid dimethyl sulfoxide, the graphene oxide may be characterized in that the production was dissolved in water, a mixed solution by mixing the two solutions Yes method of producing a pin oxide / carbon nitride self-assembling composite.
[Claim 6]
The method of claim 1, wherein the heat treatment method for manufacturing a graphene oxide / carbon nitride self-assembling complexes, characterized in that is carried out for 1 to 10 hours at 400 to 700 ℃.
[Claim 7]
Wherein the first to sixth produced by the production method according to any one of items graphene oxide / carbon nitride self-assembling composite.
[Claim 8]
The method of claim 7, wherein the graphene oxide / carbon nitride self-assembling complexes, characterized in that contained a total of graphene oxide is 1 to 50% by weight relative to the weight of the self-assembling composite.
[Claim 9]
Claim 7 graphene oxide / carbon nitride self-lithium according to claim 1, further comprising a sulfur in addition to the composite assembly according to-sulfur battery anode.
[Claim 10]
The method of claim 9, wherein the self-assembling complexes and sulfur mixed or lithium, characterized in that to form a composite structure-sulfur battery, the positive electrode.
[Claim 11]
anode; cathode; In the sulfur battery, the positive electrode is lithium, characterized in that the positive electrode according to the claim 9 or 10-separator and an electrolyte consisting of a lithium impregnated thereto, which is interposed between the sulfur battery.