Electrolyte Additive And Nonaqueous Electrolyte Solution For Lithium Secondary Battery Containing Same
Abstract:
The present invention relates to a nonaqueous electrolyte solution additive, a nonaqueous electrolyte solution for a lithium secondary battery containing the same, and a lithium secondary battery, and specifically, by providing the nonaqueous electrolyte solution containing a compound capable of increasing the effect of forming an SEI film on surfaces of a positive electrode and a negative electrode to be able to maintain a passive effect, the high temperature storage characteristics and lifetime characteristics of the lithium secondary battery can be improved.
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Notices, Deadlines & Correspondence
LG Chem Research Park, 188, Munji-ro,
Yuseong-gu,
Daejeon 34122
2. LEE, Chul Haeng
LG Chem Research Park, 188, Munji-ro,
Yuseong-gu,
Daejeon 34122
3. LEE, Kyung Mi
LG Chem Research Park, 188, Munji-ro,
Yuseong-gu,
Daejeon 34122
Specification
Art
[1]
Mutual citations and related application (s)
[2]
This application claims the benefit of priority based on the date of July 03, Korea Patent Application No. 10-2017-0084345 and No. 2 dated July 2018 Korea Patent Application No. 10-2018-0076420 2017, and of the Korea Patent Application everything described in the literature are included as part of the specification.
[3]
[4]
Art
[5]
The present invention relates to a non-aqueous electrolyte lithium secondary battery including the electrolyte additive, and it can improve the performance of the battery.
BACKGROUND
[6]
As realize the miniaturization and weight saving of electronic devices is becoming more common, the use of portable electronic devices, research on secondary batteries having high energy density as their power source has been actively conducted.
[7]
The secondary batteries include nickel-cadmium batteries, nickel-metal hydride battery, a nickel-may be made of hydrogen battery, a lithium secondary battery, etc., of which represent more than twice the discharge voltage than batteries using conventional alkali aqueous solution in addition, there is emerging research on lithium rechargeable battery charging is possible rapid high energy density per unit weight.
[8]
The lithium secondary battery is coated on the current collector on the positive or negative electrode active material to an appropriate thickness and length, or the active material applied to its own into a film decrease with an insulator membrane to or laminate made of an electrode group, and then, put into a can or similar containers, It is prepared by injecting the electrolyte. In this case, the positive electrode active material include a lithium metal oxide is used, the negative electrode active material is used as the lithium metal, a lithium alloy, a crystalline or amorphous carbon or carbon composites.
[9]
Lithium secondary batteries that can be charged and discharged proceeds lithium ion insertion (intercalation) of graphite electrode from the negative electrode of a lithium metal oxide of the positive electrode, and while repeating the process of desorption (deintercalation). The lithium is Li reacts with the carbon electrode so reactive steel 2 CO 3 to produce a, LiO, LiOH, etc. to form a film on the surface of the negative electrode. This solid electrolyte film; is called (Solid Electrolyte Interface SEI) film, the SEI film prevents lithium ions during charge and discharge and the carbon negative electrode or reaction with the other materials formed in the initial charge. Also plays a role of an ion tunnel (Tunnel Ion) is passed through only the lithium ion. That is, the tunnel ions should serve to prevent the organic solvent electrolyte of a large molecular weight, which move with it by plum (solvation) for lithium ions to be co-migration intercalation with the carbon negative electrode to disrupt the structure of the carbon negative electrode.
[10]
Therefore, in order to improve high-temperature cycle characteristics and low-temperature output of a lithium secondary battery, it must be film forming solid SEI on the anode of a lithium secondary battery.
[11]
A conventional non-aqueous electrolyte has, film is formed on a non-uniform SEI is difficult to expect the improvement of low-temperature or high-temperature output characteristic disadvantage by including the electrolyte additive of the poor characteristics. Furthermore, when not controlled to the necessary amount for the dose, even if it has the electrolyte additives, a side reaction caused by the electrolyte additives is caused a problem that ultimately increases the irreversible capacity of the secondary battery is reduced and the output characteristics.
[12]
Thus, a situation that is being developed a need for a can to form a rigid SEI film on the positive electrode and the negative electrode used as an electrolyte additive to improve the overall performance of the battery such as output characteristics, high temperature storage characteristics and life characteristics compound.
[13]
[14]
Prior Art Document
[15]
U.S. Patent Publication No. 2017-0077551 No.
Detailed Description of the Invention
SUMMARY
[16]
An object of the present invention is to provide a novel electrolyte additive to improve the overall performance, such as to solve the above problems, the output of the lithium secondary battery, the capacity, cycle characteristics and storage characteristics.
[17]
In addition, the present invention is to provide a lithium secondary battery, a non-aqueous electrolyte including a lithium salt, an organic solvent and the above electrolyte additives.
[18]
In addition, the present invention is to provide a lithium secondary battery having the non-aqueous electrolyte lithium secondary battery.
Problem solving means
[19]
In order to achieve the above object, the present invention is a compound represented by the following general formula (1); provides an electrolyte additive comprising a.
[20]
Formula 1
[21]
[22]
In the formula 1,
[23]
X 1 and X 2 and is P, Y 1 to Y 4 each is independently O or S, L is a direct bond or C 1 -C 10 divalent hydrocarbon group, R 1 to R 4 are, each independently, hydrogen , a halogen atom, a nitrile group, or the carbon number is 1 to 20 monovalent hydrocarbon group, the carbon number of 1 to 10 divalent monovalent hydrocarbon group and a C 1 -C 20 hydrocarbon group substituted or will unsubstituted, wherein said substitution is a carbon number from 1 to 20 alkyl group, having 2 to 20 carbon atoms in the alkenyl group, the alkynyl group is due, and at least one or more substituents selected from the group consisting of an aryl group having 6 to 20 carbon atoms of 2 to 20 carbon atoms.
[24]
[25]
Specifically, in the compound represented by the above formula 1, L is a substituted or unsubstituted alkylene group having 1 to 10 carbon ring, wherein R 1 to R 4 are, each independently, a halogen atom or a substituted or unsubstituted C 1 -C It can be a monovalent hydrocarbon group of 20.
[26]
More specifically, the compounds of Formula 1 may be selected from a compound represented by the following formula 1a or formula 1b.
[27]
[Chemical Formula 1a]
[28]
[29]
[30]
Formula 1b]
[31]
[32]
[33]
In one embodiment of the present invention
[34]
Lithium salt, and an organic solvent and a first additive, the first additive may provide a rechargeable lithium battery, the non-aqueous electrolyte that electrolyte additive of the present invention.
[35]
The first non-aqueous additive from about 0.1% to 6% by weight based on the total weight of the electrolyte, may be included in detail in an amount of 0.5% to 5% by weight.
[36]
[37]
The non-aqueous electrolyte may further include a second additive selected from the group consisting of a non-lithium-type additives, the lithium-type additives, and mixtures thereof.
[38]
The non-lithium-type additive may be at least one selected from carbonate compounds, phosphate compounds, borate compounds, silane phosphorus-based compound, a sulfur-containing compound, the nitrile-based compound and a benzene group consisting of fluoride-based compound.
[39]
The non-lithium-type additive, based on the total weight of the non-aqueous electrolytic solution, may be included in an amount of about 0.01% by weight to 10% by weight.
[40]
The lithium-type additive may be at least one selected from a halogenated boron-based lithium oxalate, lithium-boron-based, imidazole-based lithium, lithium phosphate-based, and the group consisting of sulfate-based lithium.
[41]
The lithium-type additive, based on the total weight of the non-aqueous electrolytic solution, may be included in an amount of about 0.01% by weight to 10% by weight.
[42]
[43]
In one embodiment of the present invention
[44]
It provides a lithium secondary battery having the non-aqueous electrolyte lithium secondary battery.
Effects of the Invention
[45]
According to the invention, it increases the stable SEI film-forming effect on the positive electrode and the negative electrode surface can provide a non-aqueous electrolyte comprising a compound capable of maintaining the passivation effect of the electrolyte additive. In addition, it is possible to manufacture the cycle capacity characteristics and high-temperature storage characteristics, the overall overall performance enhanced by the lithium secondary battery having the same.
Best Mode for Carrying Out the Invention
[46]
It will be described below a preferred embodiment of the invention; Prior to this, the specification and are should not be construed as limited to the term general and dictionary meanings used in the claims, the inventor accordingly the concept of a term to describe his own invention in the best way It interpreted based on the meanings and concepts corresponding to technical aspects of the present invention on the basis of the principle that can be defined.
[47]
Therefore, the present embodiment described in the specification configuration shown in the example is a not intended to limit the scope of the present merely nothing but a most preferred embodiment of this invention, various equivalents and modifications can be made thereto according to the present application point for example, they should be understood that there may be.
[48]
Moreover, terms that are used herein will be used to illustrate only exemplary embodiments and are not intended to limit the present invention. Expression in the singular number include a plural forms unless the context clearly indicates otherwise.
[49]
In this specification, "it comprise", "comprising is" or "gajida" and terms are exemplary of characteristics, numbers, steps, components or geotyiji to be a combination thereof specify the presence, of one or more other characteristics or more or of numbers, steps, components, or the presence or possibility of combinations thereof and are not intended to preclude.
[50]
In addition, prior to describing the present invention, in the substrate of the "carbon number of a to b" in the specification, "a" and "b" is the number of carbon atoms included in the specific functional group. That is, the functional group may include characters "a" to "b" carbon atoms. For example, "C 1 -C 5 alkylene group" has 1 to 5 carbon atoms of an alkyl group containing carbon atom, i.e., -CH 2 -, -CH 2 CH 2 -, -CH 2 CH 2 CH 2 -, - CH 2 (CH 2 ) CH-, -CH (CH 2 ) CH 2 - and -CH (CH 2 ) CH 2 CH 2 means the like.
[51]
Also, unless otherwise defined herein, "substituted" means that the at least one hydrogen bonded to the carbon substituted with elements other than hydrogen, and, for example, an alkyl group having 1 to 20 carbon atoms, having a carbon number of 2 to 20 and of an alkenyl group, an alkynyl group substituted with a means, and at least one or more substituents selected from the group consisting of an aryl group having 6 to 20 carbon atoms of 2 to 20 carbon atoms.
[52]
[53]
Electrolyte Additives
[54]
In accordance with the present disclosure, there is provided a novel electrolyte additive.
[55]
The electrolyte additive may include a compound represented by the following general formula (1).
[56]
Formula 1
[57]
[58]
In the formula 1,
[59]
X 1 and X 2 and is P, Y 1 to Y 4 each is independently O or S, L is a direct bond or C 1 -C 10 divalent hydrocarbon group, R 1 to R 4 are, each independently, hydrogen , a halogen atom, a nitrile group, or the carbon number is 1 to 20 monovalent hydrocarbon group, the carbon number of 1 to 10 divalent monovalent hydrocarbon group and a C 1 -C 20 hydrocarbon group substituted or will unsubstituted, wherein said substitution is a carbon number from 1 to 20 alkyl group, having 2 to 20 carbon atoms in the alkenyl group, the alkynyl group is due, and at least one or more substituents selected from the group consisting of an aryl group having 6 to 20 carbon atoms of 2 to 20 carbon atoms.
[60]
[61]
Specifically, in Formula 1, L as the linking group may be an alkylene of the substituted or unsubstituted 1 to 10 carbon atoms. Further, in the above formula 1, R 1 to R 4 are, each independently, a halogen, and atom or a monovalent hydrocarbon group of the substituted or unsubstituted C1 to C20, may be more preferably a halogen atom, more preferably It may be a fluorine (F).
[62]
Further, the formula (1) wherein Y 3 and Y 4 a, depending on the geometry of, the diether (diether) may be coupled or dithio ether (dithioether) bond is present, because of this combination, more excellent oxidation stability improving effect It can be expressed.
[63]
Specifically, the compounds of the formula I as described above can be selected from a compound represented by the following formula 1a or formula 1b.
[64]
[Chemical Formula 1a]
[65]
[66]
[67]
Formula 1b]
[68]
[69]
[70]
In the present invention, the compound of Formula 1 contained as an electrolyte additive may form a phosphate (difluorophosphate) uniform thin film in place of the positive and negative electrodes is contained by the structure, the decomposition at the anode surface-difluoro. That is, it is possible to, while the oxygen of the phosphate-difluoro structure adsorbed to the surface of the positive electrode the oxygen is lost, to form a thin coating to stabilize the cathode surface, the non-aqueous electrolyte solution to prevent exposure. As a result, O from the anode 2 can be suppressed to suppress the occurrence of side reactions, and the positive electrode and the electrolyte to improve the durability of the battery. Further, as the phosphate-difluoro structure is reduced during battery driving, it is possible to form solid and stable SEI film on the anode surface, it is possible to improve the durability and improving the high temperature storage characteristics of the battery.
[71]
[72]
The non-aqueous electrolyte lithium secondary battery,
[73]
In addition, it is possible to provide a non-aqueous electrolyte lithium secondary battery comprising, according to one embodiment of the present invention, the lithium salt, organic solvent and the electrolyte additive of the present invention to the first additive.
[74]
That is, the compound represented by general formula (1) contained in one additive because it is stable without decomposition even at a high temperature, does not cause a side reaction such as or decomposed at the anode surface of the non-aqueous electrolytic solution to be oxidized, and therefore, prevent the irreversible capacity increases in cell may be, it can be seen the effect of the reversible capacity increase accordingly.
[75]
[76]
The first additive of the compound is based on the total weight of the non-aqueous liquid electrolyte of the formula (I), it can be applied to a content of about 0.1% to 6% by weight, in particular 0.5% to 5% by weight, more specifically from 1 wt. It may be used in an amount of from% to 5% by weight.
[77]
The first additive when 0.1% to 6% by weight content of compound of formula 1, can form rigid SEI film on the positive electrode and the negative electrode surface, preventing an increase in resistance due to the formation over-coating at the time of initial charging electrode surface can do. At this time, if the content of the first additive exceeds 6% by weight, a side reaction caused by an excess of additives is caused, and the cycle life characteristics and capacity characteristics of the battery may be deteriorated, When the content of the first additive is less than 0.1% by weight a first additive input effects can be difficult mimihayeo, forming stable SEI membrane.
[78]
[79]
On the other hand, by, but form the compound is uniform and thin film on the anode and the cathode represented by the formula (1), by acting mainly on the anode SEI film-forming reducing the response of the other material and the positive electrode as described above, improve the durability of the battery can. Thus, the non-aqueous electrolyte lithium secondary battery of the present invention may further include a second additive which may aid in forming the cathode coating to aid in a non-aqueous electrolyte solution with a compound of formula (1) of the first additive.
[80]
These types of second additive is not particularly limited, and may specifically include lithium-type additives and / or non-lithium-type additives.
[81]
In this way, the non-aqueous lithium secondary battery of the present invention the electrolyte is the first additive by mixing the non-lithium-type additives and / or non-lithium-type additives together with the compound and the second additive of the formula I, more stable to the positive and negative electrode surface, and it is possible to form a rigid SEI film, it is possible to improve the overall performance, such as high temperature storage characteristics and life characteristics of the lithium secondary battery.
[82]
[83]
Examples of non-lithium-type additive and the lithium-type additives can used as the second additives are described below.
[84]
Non-lithium-type additive
[85]
The non-lithium-type additives as to give a synergistic effect to improve the performance of the lithium secondary battery is used in conjunction with the compound of formula (I) compounds, specifically, degradation of the solvent in the non-aqueous electrolyte, with the effect that the expression of the compound of formula (I) a can to compensate the role of inhibition and to improve the mobility of the lithium ions.
[86]
The non-lithium-type additive comprises about relative content and represented by the aforementioned formula (I) compound is not particularly limited, when the non-aqueous included in the electrolyte, on the basis of the non-aqueous electrolyte solution total weight, from about 0.01% to 10% by weight to, and can specifically specifically from 0.1% to 8% by weight, more particularly used in an amount of 0.1% to 5% by weight less than 0.05% by weight to 10% by weight. The non-lithium-type additive content of 0.01 ears is less than% by weight of non-lithium-type additives In effect, if it exceeds 10% by weight is present a side reaction caused by the excessive amount of additive can be the interfacial resistance of the SEI film increases, the capacity characteristics the overall performance may be degraded like.
[87]
[88]
Specifically, the non-lithium-type additive may be one or more selected from the group consisting of carbonate compounds, phosphate compounds, borate compounds, silane phosphorus-based compound, a sulfur-containing compound, the nitrile compound and fluorinated benzene compounds.
[89]
Hereinafter, the non-lithium type. However additive discloses specific compounds that can be used as, not limited to these compounds, in addition to being able to complement the performance gain of the compound represented by Formula 1, a carbonate-based or borate such as a system it can be used a compound having a specific exemplary.
[90]
First, the carbonate compounds, and typical examples of vinylene carbonate, may be ethylene carbonate or vinyl ethylene carbonate applied to the ethylene carbonate (FEC), difluoro-fluoro, the substituent such as alkyl group having 1 to 3 carbon atoms substituted in the compound It may be.
[91]
The carbonate compounds can be primarily formed film SEI on the anode surface during cell activation by use together with the compound represented by Formula 1 to form an SEI film on the anode, it forms a coating stable SEI even at a high temperature, durability of the battery It can be improved.
[92]
[93]
Further, the phosphate-based compound is, for example, to be represented by the formula (2).
[94]
[Formula 2]
[95]
[96]
In Formula 2,
[97]
A 1 to A 3 are, each independently, -Si (R a ) n (R b ) 3-n , or a propynyl group (-C≡C), and wherein R a and R b are each independently 1 to 4 carbon atoms It is an alkyl group, n is an integer from 0 to 3.
[98]
The phosphate-based compounds, e.g., tris (trimethylsilyl) phosphate, tris (triethylsilyl) phosphate, tris (tripropylsilyl) phosphate, bis (trimethylsilyl) (triethylsilyl) phosphate, bis (triethylsilyl) ( trimethylsilyl) phosphate, bis (tripropylsilyl) (trimethylsilyl) phosphate, bis (tri-dimethylsilyl) (may be applied include tripropylsilyl) phosphate, the alkyl groups of each silyl group to be applied are different from each other.
[99]
Further, the phosphate-based compounds may be applied, such as a di-propynyl ethyl phosphate, diethyl phosphate-propynyl.
[100]
The phosphate-based compound is within PF electrolyte 6 to which can be achieved, an increase in the durability of the battery by mixing the compound represented by Formula 1, as it can help to stabilize the positive electrode and the negative electrode film-forming and the like anions.
[101]
[102]
Further, the borate-based compound may be represented by the following general formula (3) below.
[103]
[Formula 3]
[104]
[105]
In Formula 3,
[106]
A 4 to A 6 to each independently, -Si (R c ) m (R d ) 3-m , or a propynyl group (-C≡C), and wherein R c and R d are each independently 1 to 4 carbon atoms is an alkyl group, m is an integer from 0 to 3.
[107]
The case of borate-based compound, and a silyl group or a propynyl group such as the above-described phosphate-based compound can be combined, the silyl group and propynyl group may have substituents such as exemplified in the phosphate based compound may equally be applied.
[108]
The borate-based compound material, such as by promoting the lithium salt ion pair separation, it is possible to improve the mobility of the lithium ions, it becomes possible to reduce the interface resistance of the SEI film, is generated on the battery reaction is difficult to remove LiF Fig. by dissociation, it is possible to solve problems such as HF gas.
[109]
[110]
In addition, the phosphorus-silane compounds may have a carbon number of 1 to 4 alkyl vinyl trialkyl silane, dialkyl divinyl alkyl silane, or trivinyl silane, or tert-vinyl silane can be applied.
[111]
Wherein the phosphorus compound is a silane that can be achieved, a negative increase in the durability of the battery it is possible to form a Si-based SEI coating on the negative electrode by mixing with a compound of the formula (1).
[112]
[113]
Further, the sulfur-containing compounds can be represented by the following formula (4).
[114]
[Formula 4]
[115]
[116]
In the formula 4,
[117]
Y 5 and Y 6 are each independently a direct bond, C or O, R 5 and R 6 are, each independently, a substituted or unsubstituted C1 to 10 alkyl group, a substituted or unsubstituted, having 6 to 20 carbon atoms in the ring an aryl group, or is to form a ring of four-membered ring to 7-membered ring are connected to each other, p is 1 or 2.
[118]
In Formula 4, p is 1, then S = O bonds are first numbered, R 5 and R 6 are connected to each other and at the same time form a ring, Y 5 and Y 6 when the O include sulfites (sulfite) in the series may be a sulfur-containing compound, numbered, p is 2, then S = O bond is 2, R 5 and R 6 are connected to each other and at the same time form a ring, Y 5 and Y 6 when the O, sulfate (sulfate) It can be a sulfur-containing compound in the series, and, Y in the sulfated series 5 or Y 6 when at least one of the C, there can be a sulfur-containing compound of the sultone (sultone) series. Further, p is 2, then S = O bond is two while R 5 and R 6 does not form a ring, sulfone (sulfone) may be a compound of the series.
[119]
Specifically, for example, a sulfur-containing compound is a sulfur-containing compound of methylene sulfate, ethylene sulfate, trimethylene sulfate, tetramethylene sulfate or can which the applied sulfate substituent is bonded to these alkylene, sulfite sequence of the sulfated series the methylene sulfites, ethylene sulfite, trimethylene sulfite, tetramethylene sulfide or sulfide substituents are bonded to these alkylene may be applied.
[120]
In addition, the sulfur-containing compound of the sulfone series, an alkyl group having 1 to 5 carbon atoms bonded dialkyl sulfone, the substituent is bonded to the diaryl sulfone, or a dialkyl or diaryl aryl group is bonded having 6 to 12 carbon atoms, sulfonic sulfur-containing compounds may be applied, wherein the series sultone is 1,3-propane sultone, 1,3-propene sultone, 1,4-butane sultone, 1,5-substituents are bonded sultone, or groups thereof alkylene the sultone may be applied.
[121]
Such as the sulfur-containing compounds can act that generally complements formed SEI film on the anode surface, contributing to a stable SEI film formed in the same manner as the compound represented by the aforementioned formula (1), the high temperature storage performance, and cycle life characteristics it is possible to express the effect.
[122]
[123]
Further, the nitrile-based compound is a compound represented by the formula (5) below.
[124]
[Formula 5]
[125]
[126]
In Formula 5,
[127]
R 7 is an alkylene group having 1 to 5 carbon atoms.
[128]
The nitrile-based compound is a compound containing two groups nitriles, connecting unit for connecting the two nitrile groups is an alkylene group having a carbon number may be from 1 to 5, preferably 2 to 4.
[129]
The connecting group having a carbon number of 2 to 4 or a nitrile compound of the alkylene group may be included as succinonitrile, glutaric nitrile or Ah and adiponitrile, it is included at least one of these compounds one configuration of the electrolyte additive composition. Preferably of which may be subject to a succinonitrile or adiponitrile.
[130]
The nitrile-based compound can be achieved the effect such as to give a synergistic effect in the lithium secondary battery improved performance when combined with a compound of formula I as described above, the compound, the positive electrode and the transition metal elution inhibition.
[131]
In this case, the nitrile-based compound can be expected an effect when used together with the compound of the aforementioned formula (1), improved high temperature properties to a positive / negative film stability and the like. That is, the nitrile-based compound may be responsible for, and to play a role complementary to form the anode SEI film in addition to the effect of the compound of formula (I) expression, inhibit the decomposition of the solvent in the electrolyte, a lithium ion the mobility can play a role to improve.
[132]
[133]
Further, the fluorinated benzene-based compounds such as fluorine-benzene with benzene, trifluoromethyl benzene, difluoro-fluoro that may be a benzene compound substituted instead of hydrogen.
[134]
Since as described above, as an electrolyte additive composition, since the compound represented by the formula (1), if it contains a non-lithium-type additive is capable of forming a stable and rigid SEI film on the anode and the cathode, the solvent in the non-aqueous electrolyte electrode even if there is a side reaction such as the decomposition in the vicinity can be suppressed, and accordingly long-term storage in a high temperature environment, the effect of gas production this may be significantly reduced, due to this stored improved property improving the growth and life characteristics of the reversible capacity It can be obtained.
[135]
[136]
Lithium type additive
[137]
The lithium-type additive forms a SEI film on the anode surface, with the effect that the expression a compound of the formula (1) as to give a synergistic effect to improve the performance of the lithium secondary battery of the compound of formula (I) compounds, specifically, the non-aqueous It can complement the role of suppressing the decomposition of the solvent in the electrolytic solution and improve the mobility of the lithium ions.
[138]
The lithium-type additive for the relative content of the represented by the aforementioned formula (I) compound is not particularly limited, and a non-aqueous if it is included in the electrolyte, based on the total weight of the non-aqueous electrolyte, the content of about 0.01% by weight to 10% by weight It is applied, and, preferably, can be used in an amount of 0.05% to 10% by weight, more preferably from 0.1% to 8% by weight, more preferably from 0.1% to 5% by weight. The back lithium type additive content is less than 0.01% by weight of a lithium-type additives In effect is insignificant, and when it exceeds 10% by weight cause a side reaction caused by the excessive amount of additive can be the interfacial resistance of the SEI film increases from the cathode, the capacity the overall performance characteristics, such as can be lowered.
[139]
[140]
The lithium-type additives that may be subject to a typical example halogenated boron-based lithium oxalate, lithium-boron-based, imidazole-based lithium, lithium phosphate-based, sulfate-based or lithium, can be applied to the at least one or more mixtures selected from the aforementioned.
[141]
In the following, however, it discloses the specific compound that may be used as the lithium-type additives, not limited to this compound, being able to complement the performance gain of the compound represented by the formula (1), a halogenated boron-based, oxalic boron-based , it is possible to use anything that a compound having the representative feature, such as phosphate-based.
[142]
Specifically, the halogenated boron-based lithium is, for example, lithium tetra can be a fluoro borate, lithium tetrachloro borate, lithium chlorotrifluoroethylene fluoroborate, lithium fluoroborate trichloromethyl, or lithium borate as dichloro-difluoro applied to.
[143]
The boron-based lithium oxalate can lithium bis (oxalato) borate, lithium difluoro (oxalato) borate or lithium dichloro (oxalato) borate to be applied.
[144]
The imidazole-based lithium is lithium 4,5-dicyano-2 - ((halo) o (alkyl) q ) can be imidazole, in the compound name "halo" are each independently a halogen substituent, or F be Cl, and "alkyl" each independently may be an alkyl group having 1 to 3 carbon atoms, wherein o and q is an integer from 1 to 3, it may be to satisfy o + q = 4 as alkyl substituents.
[145]
The phosphate-based lithium is, for example, a lithium-dihalo as phosphate, lithium dialkyl phosphate, lithium-dihalo (bis-oxalato) and the like phosphate and lithium dialkyl (bis-oxalato) phosphate can be applied, these compounds "a dihalo" in the name may be each independently selected from F or Cl to two halogen substituent (s), "dialkyl" may be each independently an alkyl group having 1 to 3 carbon atoms in the two alkyl substituents.
[146]
In the sulfate-based lithium is the compound designation number, and include a lithium alkyl sulfates, "alkyl" may be an alkyl group having 1 to 3 carbon atoms in the alkyl substituent.
[147]
[148]
Specifically, a lithium secondary battery of the present invention the non-aqueous electrolyte may contain a compound of first additive and the second additive at least one of the selectively non-lithium-type additive and / or a lithium-type additive with the formula (1), the the first and second additives may be included in, based on the total weight of the non-aqueous electrolyte, and preferably 0.01% to 10% by weight as described above, respectively.
[149]
However, into the first additive and the second total amount is less than 20% by weight, based on the total weight of the non-aqueous electrolyte solution, in particular from about 0.1% to 20% by weight, more specifically from 0.1% to a range of 16% by weight of additives It may need to be adjusted. At this time, the non-lithium-type Additive: due to be zero, and improve the formation effect SEI film effects, the low-temperature high-rate discharge characteristics, high-temperature stability, the overcharge protection, high-temperature swelling effect of improving the weight ratio of the lithium-type additive is from 0: 100 to 100 It can be used by adjusting the mixing ratio.
[150]
[151]
Lithium salt
[152]
On the other hand, in the non-aqueous electrolyte according to the present specification, the lithium salt may be used, without limitation, those which are commonly used in a lithium secondary battery electrolyte, such as Li cation + to include, and the anion is F - , Cl - , Br - , I - , NO 3 - , N (CN) 2 - , BF 4 - , ClO 4 - , AlO 4 - , AlCl 4 - , PF 6 - , SbF 6 - , AsF 6 - , B 10 Cl 10 -, BF 2C 2O 4 -, BC 4O 8 -, PF 4C 2O 4 -, PF 2C 4O 8 -, (CF 3) 2PF 4 -, (CF 3) 3PF 3 -, (CF 3) 4PF 2 -, (CF 3) 5PF -, (CF 3) 6P -, CF 3SO 3 -, C 4F 9SO 3 -, CF 3CF 2SO 3 -, (CF 3SO 2) 2N -, (FSO 2) 2N -, CF 3CF 2(CF 3) 2CO -, (CF 3SO 2) 2CH -, CH 3SO 3 -, CF 3(CF 2) 7SO 3 -, CF 3CO 2 -, CH 3CO 2 -, SCN - 및 (CF 3CF 2SO 2) 2N -It may be at least one selected from the group consisting of. Specifically, the lithium salt is LiCl, LiBr, LiI, LiBF 4 , LiClO 4 , LiAlO 4 , LiAlCl 4 , LiPF 6 , LiSbF 6 , LiAsF 6 , LiB 10 Cl 10 , LiCF 3 SO 3 , LiCH 3 CO 2 , LiCF 3 CO 2 , LiN (SO 2 CF 3 ) 2 (lithium (bis) trifluoromethanesulfonimide, LiTFSI), LiN (SO 2F) 2 (lithium fluorosulfonyl imide, LiFSI), LiCH 3 SO 3 and LiN (SO 2 CF 2 CF 3 ) 2 can comprise a (lithium bisperfluoroethanesulfonimide, LiBETI) danilmul or in combination of two or more thereof selected from the group consisting of.
[153]
Specifically, the electrolyte salt is LiPF 6 , LiBF 4 , LiCH 3 CO 2 , LiCF 3 CO 2 , LiCH 3 SO 3 may include, LiFSI, danilmul or in combination of two or more thereof selected from the group consisting of LiTFSI and LiBETI.
[154]
The lithium salt is typically be suitably changed to the extent possible the use, but may, be included at a concentration of 0.8 M to 1.5M in the electrolyte to obtain a corrosion resistant film-forming effect of the optimum electrode surface. If the electrolyte if the salt concentration is greater than 1.5M for a non-aqueous and the concentration of the electrolyte may be degraded, or increase wettability, it is possible to reduce the film-forming effect.
[155]
[156]
Organic solvent
[157]
In addition, the organic solvent may be decomposed due to oxidation minimized in the charge-discharge process of the secondary battery, so long as it can exhibit the desired properties with the additives, there are no restrictions. For example, ether-based solvents, ester-based organic solvent can be used as a mixture, or an amide-based organic solvent and the like, each alone, or two or more kinds.
[158]
In an ether solvent of said organic solvent is dimethyl ether, diethyl ether, dipropyl ether, methyl ethyl ether, available methyl propyl ether, and any one or a mixture of two or more of those selected from the group consisting of: ethyl propyl ether, but , and the like.
[159]
Further, the ester-based organic solvent may include at least one or more compounds selected from the group consisting of a cyclic carbonate-based organic solvent, a linear carbonate-based organic solvents, linear ester organic solvents, and cyclic ester-based organic solvent.
[160]
Specific examples of double the cyclic carbonate-based organic solvents include ethylene carbonate (ethylene carbonate, EC), propylene carbonates (propylene carbonate, PC), 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pen ethylene carbonate, 2,3-pen may have any one or a mixture of two or more of which is selected from ethylene carbonate, vinylene carbonate, and the group consisting of ethylene carbonate (FEC) fluoro.
[161]
Further, specific examples of the linear carbonate-based organic solvent is a dimethyl carbonate (dimethyl carbonate, DMC), diethyl carbonate (diethyl carbonate, DEC), dipropyl carbonate, ethyl methyl carbonate (EMC), methyl propyl carbonate and ethyl propyl carbonate It is any one or a mixture including two or more of them selected from the group consisting of may be used as a representative, and the like.
[162]
The linear ester-based organic solvent is any one or combinations selected from the specific examples of methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, and butyl propionate group consisting of such as a mixture of two or more may be used as a representative, and the like.
[163]
The cyclic ester-based organic solvents include the specific examples γ- butyrolactone, 2 out of any one or combinations selected from a lactone, γ- caprolactone, lactone, such as the group consisting of ε- caprolactone as σ- ballet as γ- ballet species, but it can use the above mixture, and the like.
[164]
FIG low viscosity, such as cyclic carbonate compounds are dimethyl carbonate and diethyl carbonate in and may preferably be used because well dissociate lithium salts in the high dielectric constant is used as the organic solvent having a high viscosity electrolyte, such a cyclic carbonate compound in the ester-based organic solvent, the low dielectric constant linear carbonate compound and linear ester compound is mixed with an appropriate ratio can make the electrolytic solution having high electric conductivity may be used more preferably.
[165]
On the other hand, the organic solvent may be a mixed organic solvent, a mixture of three kinds of the carbonate-based solvent, the ternary system when using the non-aqueous organic solvent, it is possible to more preferably, for example, which can be used in the mixed organic solvent compound is, there may be ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, ethyl methyl carbonate, vinylene carbonate, fluorinated ethylene carbonate, methyl propyl carbonate, ethyl propyl carbonate, and the like, 3 kinds selected from among the carbonate-based compound may have a mixed solvent is applied.
[166]
[167]
The lithium secondary battery
[168]
A In accordance with the present specification, there is a lithium secondary battery comprising the above-mentioned lithium secondary battery, the electrolyte can be provided, the lithium secondary battery is placed between the negative electrode, the positive electrode and the negative electrode including a positive electrode, a negative electrode active material comprising a positive electrode active material It includes a separation membrane and the above-mentioned electrolyte.
[169]
The lithium secondary battery of the present invention can be produced according to the conventional method known in the art. For example, it is possible to put the porosity of the separator between the positive electrode and the negative electrode prepared by putting an electrolyte with a lithium salt is dissolved.
[170]
[171]
The positive electrode may be manufactured by forming a positive electrode material mixture layer on a positive electrode collector. The positive electrode material mixture layer can be formed by drying, rolling, and then coating the cathode slurry comprising a cathode active material, a binder, a conductive material and a solvent or the like onto the positive electrode collector.
[172]
The cathode current collector is so long as it has suitable conductivity without causing chemical changes in the fabricated battery is not particularly limited, for example, stainless steel, aluminum, nickel, titanium, sintered carbon, or carbon on the surface of aluminum or stainless steel , nickel, titanium, can be used as such as to a surface treatment or the like.
[173]
The positive electrode active material is a reversible intercalation and de capable of intercalation compounds of lithium, specifically, it may comprise a lithium composite metal oxide containing at least one metal and lithium such as cobalt, manganese, nickel or aluminum have. More specifically, the lithium composite metal oxide is the lithium-manganese-based oxide (for example, LiMnO 2 , LiMn 2 O 4 and the like), lithium-cobalt oxide (e.g., LiCoO 2 and the like), lithium-nickel-based oxide (for example, LiNiO 2 and the like), lithium-nickel-manganese-based oxide (for example, LiNi 1-Y Mn Y O 2 (where, 0
Documents
Application Documents
#
Name
Date
1
201917025383-TRANSLATIOIN OF PRIOIRTY DOCUMENTS ETC. [26-06-2019(online)].pdf
2019-06-26
2
201917025383-STATEMENT OF UNDERTAKING (FORM 3) [26-06-2019(online)].pdf