NEGATIVE ELECTRODE FOR SECONDARY BATTERY COMPRISING CMC-LI SALT AND LITHIUM SECONDARY BATTERY COMPRISING SAME

Thus, the present invention according to the secondary battery cathode, anode active material, number and water binder is applied on a current collector cathode including more sum number as a cathode for a secondary battery, said number is more lithium carboxylic methyl group (- CH₂ COOLi) hydroxy (- OH) of substitution degree by 0. 7 To 1. 5 In CMC-a Li salt (lithium carboxymethyl cellulose salt) and, based on the total content of 0 contrast sum number number thickening said cathode. 6 Exceeds to 1% by weight. 4 0.1 Weight % hereinafter characterized.

Of the existing method CMC is sodium carboxy methyl group (- CH₂ COONa) including CMC-a Na salt in an a generally used. CMC-a Na salt binder overall performance of secondary battery also be the case that a but, life characteristics, discharge characteristics, process for preparing solids content increase in cathode efficiency and number speed dial setup.

According to the present invention, said CMC-a Li salt when used more number, compared with power consumption of the existing method CMC-a Na salts, secondary battery-alk, discharge characteristics, process for preparing silica gel solids content in cathode efficiency and number flow tides. In particular, CMC-a Li salt lithium carboxylic methyl group (- CH₂ COOLi) hydroxy (- OH) of substitution degree by 0. 7 To 1. 5 In CMC-a Li salt (lithium carboxymethyl cellulose salt) and, based on the total content of 0 contrast sum number number thickening said cathode. 6 Exceeds to 1% by weight. 4 Weight % hereinafter when, secondary battery recharge characteristics can be remarkably improved.

Specifically, the content of thickening said number based on the total weight contrast sum cathode number 0. 8 To 1% by weight. 2 Implementation being % by weight.

0 Total sum number number cathode content of more contrast. 6 Weight % hereinafter is filled in, CMC-a Na salt used as more number compared with the rapid charging characteristics rather can be reduced and, 1. 4% By weight greater than energy density is reduced in the content of active material in an electrode may cause a decrease in disclosed.

On the other hand, number of cathode current collector electrode overlapped with the sum in mobile index of loading amounts of lithium ions, as part of the cathode when charge can be applied to the deposition of lithium, lithium ion can be moved sufficiently before charging voltage rises is terminated, charge capacity can be reduced. I.e., rapid-filling characteristics can be conductive. The phenomenon of sum number increases along the cathode loading amounts can be more serious.

In one embodiments, the cathode loading amounts of said sum number 200 mg/25 cm² More 500 mg/25 cm² May be less than, specifically, 300 mg/25 cm² To 400 mg/25 cm² Implementation being.

Cathode loading amount sum number 200 mg/25 cm² Blast furnace charge or more decoding electrode conductive substances known. Cathode loading amount sum number 200 mg/25 cm² If the need for low piece loading amounts less than charge characteristics through improvement which, CMC-a Na salts is improved compared with the rapid-filling characteristics can be small disclosed. Cathode loading amount sum number 500 mg/25 cm² Or more compared with the charge properties even when the CMC-a Na salts of the inner edge has a special order or, in this case, sufficient levels of lithium ions is too commercially in moving distance thereof can hardly ensure quick charge of.

One specific embodiment, said CMC-a Li salt of substitution in lithium carboxylic methyl group 0. 8 To 1. And Wednesday 4, such range, more portable phone number that increases a viscosity can be, in addition, can be effect of charge formed by the adhesive agent.

On the other hand, if the number average molecular weight of 500 to only 70 and CMC-a Li salt, a molecular weight of 120 to 350 if only be. Only if a number average molecular weight less than 70 is connected to a number of large quantities of low viscosity increase more and, only if viscosity of greater than 500 does not thereof can not greater increase in the high speed charging characteristics easily.

One specific embodiment, said cathode is to be applied to the viscosity of a slurry for sum number on a current collector, but one greatly number 802.11a packets, 23 °C, B type viscometer 12 rpm measurement conditions 500 cps to 10,000 cps implementation being.

On the other hand, the aqueous binder said SBR (styrene-a butadiene rubber) implementation being. As aqueous binder, SBR emulsion form is dispersed in water an organic solvent can be reduced, and the content of negative electrode active material is reduced and sector is added to the binder content of high capacity lithium secondary battery each of the disclosed. In particular, when the thickening with SBR number said CMC-a Li salts, cathode active materials for the body portion expanded in high ratio the same sum number per pixel, negative electrode slurry containing solids content improved the safety of an increase in electrode processability of the inner flow tides.

Said CMC-a Li salt number when using more regularly particle diameter numerical range as the SBR, secondary battery can be further improve performance. In one embodiments, the particle diameter of 90 nm to 500 nm may be said SBR, particularly, implementation being 400 nm to 100 nm.

In addition, one specific embodiment, said method comprises the steps of 1:2 to 5:1 by weight aqueous binder and more number may be, provided can have a 1:1 to 4:1, 2:1 can be provided less than 1:1 but not more.

According to the present invention, a lithium secondary battery manufactured by mixing said negative electrode active material can be used without a number typically used, for example, difficulty graphitization carbon, such as graphitic carbon carbon-containing substance; Li_x Fe₂ O₃ (0 ≤ x ≤ 1), Li_x WO₂ (0 ≤ x ≤ 1), Sn_x Me_{1 A-x} Me '_y O_z (Me: Mn, Fe, Pb, Ge; Me ': Al, B, P, Si, the periodic table group 1, group 2, group 3, halogen; 0<x ≤ 1; 1 ≤ y ≤ 3; 1 ≤ z ≤ 8) such as metal composite oxide; lithium metal; lithium alloy; silicone-based alloy; tin-base alloy; SnO, SnO₂ , PbO, PbO₂ , Pb₂ O₃ , Pb₃ O₄ , Sb₂ O₃ , Sb₂ O₄ , Sb₂ O₅ , GeO, GeO₂ , Bi₂ O₃ , Bi₂ O₄ , And Bi₂ O₅ Metal oxide; polythienylene such as conductive polymer; Li provided Co-a Ni-based material can be use.

But, all cathode active material has the same result indicated, during said negative active material qualities, carbon-based material the case can exhibit an excellent effect. Particularly, said carbon-containing substance comprises graphite carbon, coke carbon, soft carbon and one or more selected from the group consisting be a hard styrene butadiene rubber.

This natural graphite is scale-like natural graphite grinding raw material, assembly number can be spherical form high pressure liquid coolant, the number prepared by the spherical natural graphite is, in electrolyte decomposition reaction material is at least a specific surface area can be reduced. The, said spherical natural graphite in the form of natural graphite and mixed after assembling disclosed is a filling density is increased and when electrode, energy density can be improved.

More particularly, manufactured by mixing said natural graphite, artificial graphite, artificial graphite or natural graphite and can be.

On the other hand, said sum number cathode includes a conductive material, filling number, or number and filling can be further comprises conductive material.

Said conductive material typically negative pole active material mixture in an amount from 0. 1 To 30% by weight can be added. This conductive material without chemical change easier to cell number one has the specially if the conductive have, for example, graphite; carbon black, acetylene black, [khey tsien black, channel black, furnace black, lamp black, there is a black carbon black; carbon fiber metal fibers and the like conductive fibers; carbon fluoride, aluminum, nickel powder metal powder; zinc oxide, conductive potassium titanate whisky; conductive metal oxide such as titanium oxide; polyphenylene derivatives such as is used as the conductive material can be. Specific examples of the ball chain lever-conductors is acetylene black or black (Denka Singapore Private Limited) (Chevron Chemical Company) magnetron chemical company [...][...], gulf oil company like number (Gulf Oil Company)), [khey black (Ketjenblack), EC-based (company elimination film (Armak Company) number article), [...] XC provided 72 (Vulcan) (it digs up, the boat company (Cabot Company) number article) and a super (Super) P etc. (Timcal yarn number article).

Filling said number of an electrode expansion component and optionally used as billion number, the cell without chemical change has the number one specially if the fibrous material, e.g., polyethylene, polypropylene polymerization number of [...]; glass fiber, of fibrous material such as carbon fiber can be used.

One particular in one example, the cell without chemical change said cathode current collector has a specially if the number is not one which have conductive, e.g., copper, stainless steel, aluminum, nickel, titanium, plastic carbon, either of copper carbon surface of stainless steel, nickel, titanium, surface treated with a like, cadmium alloy is used as the aluminum - can be. In addition, as with the positive electrode, negative electrode active material formed on the surface of the ridges and grooves may be fill, film, sheet, foil, net, porous, foam, such as a nonwoven fabric can be used in various forms.

The thickness of the cathode current collector in the present invention within the range of 3 to 201 micro m may all be the same but, in some cases each may have different values.

The present invention refers to in addition, including said secondary battery cathode number [...] substrate.

One specific embodiment, said secondary battery 1. 5 To 35% SOC (state of charge) exceeds the molybdenum [...] C-a rate charge targeting (Li plating) point can be generated. Recorded initial charging lithium [...] caused complex lithium ion from being moved so as a negative electrode active material, the pack density are formed to be coated. The, embodiment fast charging is preferably recorded later when lithium [...] to utilization, as processed fast charging is performed before recorded [...] lithium, lithium [...] recorded is applied at a low rate preferably not applied to the filling. The present invention according to secondary battery, lithium [...] SOC 35% recorded exceeds point comparison, until at least SOC 35% point can be embodiment fast charging, charging density to more rapidly filling while maintaining secondary battery can be.

On the other hand, method for charge characteristics include, e.g., lithium [...] generating SOC measuring levels recorded and is present, 1. 5 C-a rate or more C-a rate measured SOC voltage (voltage plateau) flat face are initiated, after charging to the SOC70 C-a rate corresponding to, current voltage is recovery of a single voltage recovery without rest (rest) state measuring method is present. As well as, the SOC measured large, fast recovery ratio can be evaluates the state of the charge increases.

But, when increased loading amounts cathode lithium [...] SOC is reduced proportional recorded generating efficiency of the pipe. The, secondary battery recharge film or sheet is in order to objectively evaluating, loading amounts from undergoing the necessary contrast targeting evaluation cathode lithium [...] 2000.

On the other hand, said secondary cell includes an anode, cathode, separator, and electrolyte which, hereinafter, said secondary battery of the other ingredients by the barrier metals other.

Said anode, e.g., anode current collector positive electrode active material, conductive material and binder are mixed film is sum number number bath can be applied to an anode, said anode further number regardless of the sum number can be added if necessary.

Said anode current collector has a thickness of generally 3 - 201 is micro m number tank, the cell has a particularly high conductivity without chemical change and if not one number, e.g., stainless steel, aluminum, nickel, titanium, and aluminum or carbon surface of stainless steel, nickel, titanium or silver surface has been treated using one of a variety can be selected among, particularly aluminum can be used. The current collector has a force positive active material formed on its surface may be a fine concavoconvex, film, sheet, foil, net, porous, foam, nonwoven fabric such as a permits various forms.

Said positive electrode active material, e.g., lithium cobalt oxide (LiCoO₂ ), Lithium nickel oxide (LiNiO₂ ) Or 1 or more transition metal substituted compounds such as lamellar compound; formula Li_{1 + X} Mn_{2 A-x} O₄ (Wherein, x is 0 - 0. 33 That would yield), LiMnO₃ , LiMn₂ O₃ , LiMnO₂ Such as lithium manganese oxide; lithium copper oxide (Li₂ CuO₂ ); LiV₃ O₈ , LiV₃ O₄ , V₂ O₅ , Cu₂ V₂ O₇ Such as vanadium oxide; formula LiNi_{1 A-x} M_x O₂ (Wherein, M=Co, Mn, Al, Cu, Fe, Mg, and B or Ga, x=0. 01 - 0. 3 That would yield a) represented Ni site type lithium nickel oxide; formula LiMn_{2 A-x} M_x O₂ (Wherein, M=Co, Ni, Fe, Cr, and Zn or Ta, x=0. 01 - 0. 1 That would yield) or Li₂ Mn₃ MO₈ (Wherein, M=Fe, Co, Ni, Cu or Zn that would yield a) represented lithium-manganese complex oxide; part of alkaline earth metal ions substituted LiMn formula Li₂ O₄ ; Disulfide compound; Fe₂ (MoO₄ )₃ But as to the, these only and not limited.

Said anode current collector included a conduction material such as a binder and coupled binding to that assists in the ingredient, 1 to 30% by weight based on the total weight including an anode active material mixture to typically are included. Examples of such binder, polyvinylidene fluoride, polyvinyl alcohol, carboxylic [...] (CMC), starch, hydroxy pro will bloom and with the rule which it will count woods, reproducing cellulose, polyvinyl pyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene - propylene - diene polymer (EPDM) terpenes, sulfonated EPDM, styrene - butadiene rubber, fluorine rubber, various polymer or copolymer is cited.

One specific embodiment, said separation membrane can, commonly used in the art polyolefin-based film may be, for example, high density polyethylene, low density polyethylene, linear low density polyethylene, ultra high molecular weight polyethylene, polypropylene, polyethylene terephthalate (polyethyleneterephthalate), polybutylene terephthalate (polybutyleneterephthalate), polyester (polyester), polyacetal (polyacetal), polyamide (polyamide), polycarbonate (polycarbonate), polyimide (polyimide), polyether ether keton (polyetheretherketone), polyethersulfone (polyethersulfone), poly phenyl [leyn oxide (polyphenyleneoxide), polyphenylene sulfide to (polyphenylenesulfidro), polyethylene naphthalene (polyethylenenaphthalene) and comprised of at least one selected from the group consisting of a mixture of be a sheet.

Said separation membrane can, but may be of the same material, and are not limited to, battery cell safety, energy density, and the overall depending upon the performance, as well as the same number of different material are disclosed.

Said special number is cannot be one layer or separating film of pore sizes and pores diagram, pore diagram 10 to 95% range, pore size (diameter) is 0. 1 To 50 micro m implementation being. Pore size and pores each degree 0. 1 Micro m and less than 10% if resistance layer and act, pore size and pores 50 degree exceeds 95% is applied to the micro m and difficult properties to be coated.

The electrolyte comprises lithium salt-containing nonaqueous electrolyte may be said, said lithium salt-containing nonaqueous electrolyte lithium salt and nonaqueous electrolyte cell has a coated, said nonaqueous electrolyte include a nonaqueous organic solvent, organic solid electrolyte, but not the limited only inorganic solid electrolyte is used as the alkali.

Said nonaqueous organic solvent, e.g., N - methyl - 2 - pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, gamma - butyl lactone, 1, 2 - dimethoxy ethane, tetra [tu rock hour [phwu column, 2 - methyl tetrahydrofuran, dimethyl sulfoxide, 1, 3 - [...], formamide, dimethyl formamide, [...], acetonitrile, nitroparaffins, methyl formate, acetic methyl, phosphate triester, trimethoxy methane, [...] derivatives, sulfonyl stores, methyl sulfonyl stores, 1, 3 - dimethyl - 2 - imidazolidinone, propylene carbonate derivatives, maleic acid derivatives to tetrahydrofuran derivatives, ether, methyl fatigue the blood it comes it buys, such as aprotic organic solvent is used in phenylpropionic acid ethyl can be.

Said organic solid electrolyte include, e.g., polyethylene derivatives, polyethylene oxide derivative, polypropylene oxide derivative, phosphate ester polymer, poly edge station lysine (agitation lysine), polyester sulfide, polyvinyl alcohol, polyvinylidene fluoride, including a polymer is used as the ionic dissociation number can be.

Said inorganic solid electrolyte include, e.g., Li₃ N, LiI, Li₅ NI₂ , Li₃ N provided LiI non-LiOH, LiSiO₄ , LiSiO₄ - LiI non-LiOH, Li₂ SiS₃ , Li₄ SiO₄ , Li₄ SiO₄ - LiI non-LiOH, Li₃ PO₄ - Li₂ S provided SiS₂ Li such as nitride, halide, sulfate is used as the alkali can be.

Said non-aqueous electrolyte as lithium salt dissolve said good, e.g., LiCl, LiBr, LiI, LiClO₄ , LiBF₄ , LiB₁₀ Cl₁₀ , LiPF₆ , LiCF₃ SO₃ , LiCF₃ CO₂ , LiAsF₆ , LiSbF₆ , LiAlCl₄ , CH₃ SO₃ Li, (CF₃ SO₂ )₂ NLi, chloro borane lithium, lower aliphatic carboxylic acid lithium, lithium acid 4, imide or the like can be used.

In addition, nonaqueous electrolyte is charge and discharge characteristics, flame retardant is caused by, for example, pyridine, tri-ethyl phosphite, high pressure, cyclic ether, ethylenediamine, n - glymes (glyme), tree process phosphoric acid amide, nitrobenzene derivatives, sulfur, quinone imine dyes, N - substituted oxazolidinone, N, N - substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salts, pyrrole, 2 - methoxy ethanol, added three ammoniums such as aluminum may be filled. Optionally a, in order to add adhesive, carbon tetrachloride, halogen-containing solvent such as three discordant ethylene may be further included, in order to improve the temperature preservation properties may be further gas carbonate dioxide, FEC (Fluoro-a Ethylene Carbonate), PRS (Propene sultone) further may be included in the disclosed.

One particular in one example, LiPF₆ , LiClO₄ , LiBF₄ , LiN (SO₂ CF₃ )₂ Such as a lithium salt, solvent viscosity low-EC or PC annular carbonate solvent DEC, DMC or EMC of lithium salt-containing nonaqueous electrolyte is added to the number of linear carbonate mixed solvent can be high pressure liquid coolant.

The present invention refers to in addition, a unit cell such as a battery pack including a secondary battery, a battery pack and including device can be used as a number [...] substrate.

Said device, e.g., notebook computer, net book, tablet PC, mobile phone, MP3, wearable electronic device, power tool (power tool), electric vehicle (Electric Vehicle, EV), hybrid electric vehicle (Hybrid Electric Vehicle, HEV), plug - in hybrid electric vehicle (Plug provided in Hybrid Electric Vehicle, PHEV), electric bicycle (E-a bike), electric scooter (E-a scooter), electric golf cart (electric golf cart), but a system or power storage, not limited to these only the concave disclosed.

Since the contrast method publicly known structure and the small number of such devices, the specification details omitted in its description as follows.