KR20220013814A - Prelithiation solution and method of manufacturing prelithiated anode using the same - Google Patents

Abstract

The present invention relates to a pre-lithiated solution and a method for manufacturing a pre-lithiated negative electrode using the same. According to a pre-lithiated solution and a method for manufacturing a pre-lithiated negative electrode using the same of the present invention, lithium ions can be uniformly inserted throughout a negative electrode in a solution phase through a simple process of immersing a negative electrode in a solution using a pre-lithiated solution having a sufficiently low oxidation-reduction potential compared to a negative electrode active material, and a high level of pre-lithiation can be achieved. The pre-lithiated negative electrode prepared by the above method has an ideal initial coulombic efficiency, and a lithium ion battery having a high energy density can be manufactured based thereon. In addition, the prepared negative electrode has the advantage of being suitable for mass production based on excellent stability even in a dry atmosphere.

Description

Prelithiation solution and method of manufacturing prelithiated anode using the same

The present invention relates to a prelithiated solution and a method for manufacturing a prelithiated anode using the same.

The energy density of a lithium-ion battery is determined by the voltage of the cell and the number of Li ions delivered to the electrochemical reaction per cell volume (or mass). In a real cell, an irreversible electrochemical reduction reaction of the electrolyte that forms a solid-electrolyte interphase (SEI) on the negative electrode on the first cycle occurs in the first cycle, which consumes the active lithium ions originally loaded on the positive electrode prior to cycling. Therefore, there is a problem of lowering the coulombic efficiency of battery operation.

This reduced active lithium ion greatly limits the usable energy density of the battery in the next cycle. Graphite, which is commercially available as an anode for lithium-ion batteries, generally exhibits about 90% of the initial coulombic efficiency, while silicon and silicon and oxide (SiOx), which are next-generation high-capacity anode materials, generally exhibit a coulombic efficiency of less than 80% in the initial stage, which is an obstacle to commercialization. This is becoming a situation.

In order to maximize the initial high coulombic efficiency and energy density, attempts have been made to compensate the loss of active lithium ions with extra lithium ions through prelithiation prior to battery assembly. As part of the attempt, a method of adding solid lithium particles or a lithium compound as a sacrificial lithium source during the manufacturing process of the electrode has been proposed. However, nano-sized additives are difficult to synthesize on a large scale, require a solvent different from the typical solvent used for conventional electrode manufacturing, and a new process accordingly, and impurity generation in the electrode is unavoidable, thereby lowering the net energy density. have.

An alternative is to prelithiate the lithium metal by physically contacting the prepared electrode, but there is a problem in that it is difficult to precisely control the lithium doping amount in physically contacting the lithium metal. A method of electrochemically prelithiating the electrode by making a temporary cell using lithium metal as the negative electrode has also been proposed, but it is not suitable for commercialization because it requires an additional reassembly step of the battery.

Holtstiege, F., Barmann, P., Nolle, R., Winter, M. & Placke, T. Pre-lithiation strategies for rechargeable energy storage technologies: Concepts, promises and challenges. Batteries 4,4 (2018). Sun, Y. et al. High-capacity battery cathode prelithiation to offset initial lithium loss. Nat. Energy 1, 1-7 (2016).

Therefore, the technical problem to be solved by the present invention is a high-reduction pre-lithiation solution capable of pre-lithiation of a high-capacity negative electrode for a lithium-ion battery having a low voltage of less than 0.3 V by a chemical method, and the preparation of a pre-lithiated negative electrode using the same to provide a way

One aspect of the present invention provides a prelithiation solution comprising a complex of an aromatic hydrocarbon derivative containing at least one benzene ring having a substituent other than lithium ions and hydrogen.

Another aspect of the present invention comprises the steps of (a) preparing a negative electrode comprising a negative electrode active material layer formed on one or both surfaces of a current collector; and (b) immersing the negative electrode in a prelithiated solution containing a complex of an aromatic hydrocarbon derivative containing at least one benzene ring having a substituent other than lithium ions and hydrogen to prepare a prelithiated negative electrode; It provides a method for manufacturing a pre-lithiated negative electrode comprising.

Another aspect of the present invention provides a prelithiated negative electrode manufactured according to the above manufacturing method.

Another aspect of the present invention provides a lithium ion battery including the prelithiated negative electrode.

Another aspect of the present invention provides a lithium ion capacitor including the prelithiated negative electrode.

The pre-lithiation solution and the method for manufacturing a pre-lithiated negative electrode using the same according to the present invention are prepared in a solution phase through a simple process of immersing the negative electrode in the solution using a pre-lithiation solution having a sufficiently low oxidation-reduction potential compared to the negative electrode active material. Chemically, lithium ions can be uniformly intercalated throughout the anode, and a high level of prelithiation can be achieved. The prelithiated negative electrode prepared by the above method has an ideal initial coulombic efficiency close to 100%, and a lithium ion battery having a high energy density can be manufactured based on this. In addition, the prepared negative electrode has the advantage of being suitable for mass production based on excellent stability even in a dry atmosphere.

1A is a cyclic voltammetry analysis result of an aromatic hydrocarbon compound used to prepare a prelithiation solution according to an embodiment of the present invention.
1B is a graph showing the correlation between the calculated LUMO energy and the redox potential (E _1/2 ) of an aromatic hydrocarbon compound used for preparing a prelithiation solution according to an embodiment of the present invention.
1C is a graph showing the correlation between the initial Coulombic efficiency and the redox potential (E _1/2 ) of the aromatic hydrocarbon compound used for preparing the prelithiation solution according to an embodiment of the present invention.
1D is a voltage profile of the first charge-discharge cycle of a prelithiated SiOx cathode and a pure SiOx electrode prepared according to an embodiment of the present invention.
1E is a graph showing the electrochemical titration of the amount of active lithium ions stored in the SiOx electrode after prelithiation.
Figure 2a is a graph showing the relationship between the redox potential and temperature of 4,4'-DMBP.
2B is an initial voltage profile of an SiOx anode manufactured by changing a prelithiation temperature according to an embodiment of the present invention.
FIG. 2c is an initial coulombic efficiency and open circuit voltage (OCV) measurement result of an electrode manufactured by varying the settling time according to an embodiment of the present invention, and FIG. 2d is an initial voltage profile.
3a is a Li 1s spectrum XPS analysis result of a pure electrode and a prelithiated electrode according to an embodiment of the present invention, and FIG. 3b is a Si 2p spectrum analysis result.
3c shows Li- after reacting with the SiOx electrode by varying the loading amount of DME, 4,4'-DMBP, Li-4,4'-DMBP (LAC), and Li:Si=3:1 and 1:1. FT-IR spectrum of 4,4'-DMBP (LAC) solution.
3d is an expected FT-IR spectrum of neutral and radical anions of 4,4'-DMBP showing the expected vibration frequency of 4,4'-DMBP through DFT calculation.
3e is a photograph of the lithium-aromatic hydrocarbon derivative complex solution used in FIG. 3c.
3F is a pore size distribution histogram of a prelithiated electrode according to an embodiment of the present invention.
3G is a cross-sectional SEM image of a pure SiOx cathode (pristine SiOx) and a prelithiated SiOx cathode (prelithiated SiOx) according to an embodiment of the present invention, and FIG. 3H is a pure Si cathode including Si particles having a size of 100 nm. and a cross-sectional SEM image of the prelithiated Si cathode.
4A is an initial electrochemical cycle voltage profile of LiNi _0.5 Mn _0.3 Co _0.2 O ₂ (NMC532)||bare SiOx full cell (NBFC) and NMC532||prelithiated SiOx full cell (NPFC) according to an embodiment of the present invention. .
4B is a voltage profile of an initial cycle of a full cell having a prelithiated SiOx cathode and a full cell including a conventional graphite anode according to an embodiment of the present invention.
FIG. 4c is anode and cathode voltage profiles of an NBFC according to an embodiment of the present invention, and FIG. 4d is anode and cathode voltage profiles of an NPFC.
4E is a result of measuring the initial coulombic efficiency, OCV, and electrode profile according to the dry air exposure time of the prelithiated SiOx anode according to an embodiment of the present invention.
Figure 4f is a view for explaining the roll-to-roll process of the manufacturing method of the pre-lithiated negative electrode according to the present invention.
5 is a result of measuring the OCV of the pre-lithiated anode according to an embodiment of the present invention.
6 is a result of measuring the voltage profile and Coulombic efficiency of the anode prelithiated with a prelithiated solution containing a naphthalene derivative according to an embodiment of the present invention.

Hereinafter, various aspects and various embodiments of the present invention will be described in more detail.

One aspect of the present invention provides a prelithiation solution comprising a complex of an aromatic hydrocarbon derivative containing at least one benzene ring having a substituent other than lithium ions and hydrogen.

Unlike other prelithiation methods, chemical prelithiation has a unique reaction uniformity and a simple process, so it is advantageous to apply to mass production processes. Conventionally, in chemical prelithiation, it was possible to improve the initial coulombic efficiency by using a reducing compound containing lithium or to form a protective film, thereby forming SEI during pretreatment to partially improve the coulombic efficiency. It did not have a sufficiently low redox potential) to achieve the ideal active lithium content. In particular, silicon-based electrodes (Si/SiOx) having a low redox potential have not succeeded in achieving 100% coulombic efficiency by chemical lithiation. However, it was confirmed that the pre-lithiation solution according to the present invention has a low redox potential of 0.25 V or less by modifying the molecule with an electron donor substituent, and has sufficient reducing power for pre-lithiation. The prelithiation solution according to the present invention enabled successful chemical prelithiation even in a silicon-based electrode, and lithium was uniformly inserted throughout the electrode.

More specifically, aromatic hydrocarbons (naphthalene, anthracene, phenanthrene, tetracene, azulene, fluoranthene, phenylanthracene, diphenylanthracene, perylene, pyrene, triphenylene) that do not include a benzene ring to which a substituent is bonded. , bianthryl, biphenyl, terphenyl, quaterphenyl, stilbene, etc.) and lithium ion complexes have a higher reduction potential (0.33 V vs Li/Li+ or more) than silicon-based anodes (~0.25 V). There was an aspect that chemical lithium insertion was impossible and only SEI was formed, making it unsuitable for prelithiation of silicon-based anodes. Therefore, for ideal chemical lithiation of the negative electrode, it is necessary to adjust the electrochemical potential of the pre-lithiation solution to be lower than the potential of the negative electrode. Therefore, the pre-lithiation solution according to the present invention lowers the oxidation-reduction potential by applying a complex of an aromatic hydrocarbon derivative and lithium ions having appropriately changed substituents bonded to the benzene ring of the aromatic hydrocarbon, thereby reducing the lithium ions to the negative electrode, especially silicon-based. Lithium can be chemically inserted into the negative electrode. The silicon-based negative electrode that has undergone the pre-lithiation reaction through the pre-lithiation solution containing the complex has improved electrochemical reversibility, and the solid-electrolyte interface (SEI) formation and volume expansion, which are pointed out as chronic problems of the silicon-based negative electrode, are alleviated. can do it

The aromatic hydrocarbon derivative may be a polycyclic aromatic compound having 10 to 22 carbon atoms excluding the substituent. Aromatic hydrocarbons having less than 10 carbon atoms have a lower reduction potential than Li, making it impossible to form a complex solution of Li ions and aromatic hydrocarbon derivatives.

Specifically, the aromatic hydrocarbon derivatives include naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, tetracene derivatives, azulene derivatives, fluoranthene derivatives, phenylanthracene derivatives, perylene derivatives, pyrene derivatives, triphenylene derivatives, biphenyl It may be at least one member selected from the group consisting of derivatives, terphenyl derivatives and stilbene derivatives, and preferably at least one member selected from naphthalene derivatives and biphenyl derivatives.

The aromatic hydrocarbon derivative may contain one or more substituents selected from alkyl having 1 to 6 carbon atoms, aryl having 6 to 20 carbon atoms, alkoxy having 1 to 10 carbon atoms, and alkyl halides having 1 to 6 carbon atoms, preferably having 1 carbon atom. to 4 alkyl as a substituent.

The substituent of the aromatic hydrocarbon derivative may have the same structure as the original molecule of the aromatic hydrocarbon. For example, the anthracene derivative may include an anthryl group as a substituent, and the biphenyl derivative may include biphenyl as a substituent.

The aromatic hydrocarbon derivative may be at least one selected from the group consisting of compounds represented by any one of Chemical Formulas 1 and 2.

[Formula 1]

In Formula 1, R ₁ and R ₂ are the same as or different from each other and are alkyl having 1 to 6 carbon atoms, aryl having 6 to 20 carbon atoms, alkoxy having 1 to 10 carbon atoms, or an alkyl halide having 1 to 6 carbon atoms, a and b are each independently an integer of 0 to 5, at least one is not 0, when a is 2 or more, two or more R ₁ are the same or different from each other, and when b is 2 or more, two or more R ₂ are the same or different from each other,

[Formula 2]

In Formula 2, R ₃ and R ₄ are the same as or different from each other and are alkyl having 1 to 6 carbon atoms, aryl having 6 to 20 carbon atoms, alkoxy having 1 to 10 carbon atoms, or alkyl halide having 1 to 6 carbon atoms, c and d are each other It is independently an integer of 0 to 5, at least one is not 0, when c is 2 or more, two or more R ₃ are the same or different from each other, and when d is 2 or more, two or more R ₄ are the same or different from each other.

The pre-lithiated solution satisfying the above conditions forms a protective layer on the surface of the electrode, and the formed protective layer provides stability to the pre-lithiated electrode even in a dry atmosphere, so there is an advantage in the manufacturing process.

According to a preferred embodiment, in Formula 1, R ₁ and R ₂ are the same as or different from each other and are alkyl having 1 to 4 carbon atoms, a and b are each independently an integer of 0 to 2, at least one of which is 0 No, when a is 2 or more, two or more R ₁ are the same as or different from each other, and when b is 2 or more, two or more R ₂ are the same or different from each other. In addition, in Formula 2, R ₃ and R ₄ are the same as or different from each other and are alkyl having 1 to 4 carbon atoms, c and d are each independently an integer of 0 to 2, at least one is not 0, and c is 2 When d is 2 or more, two or more R ₃ are the same as or different from each other, and when d is 2 or more, two or more R ₄ are the same or different from each other.

Under the above conditions, the composite of lithium ions and aromatic hydrocarbon derivatives has a sufficiently low oxidation-reduction potential compared to a silicon-based anode, so it can be applied to chemical prelithiation of a silicon-based anode, and the initial Coulombic efficiency is improved compared to a pure silicon-based anode.

According to a preferred embodiment, the aromatic hydrocarbon derivative may be at least one selected from the group consisting of compounds represented by any one of the following Chemical Formulas 1-1 to 1-3 and 2-1 to 2-3.

[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

[Formula 2-1]

[Formula 2-2]

[Formula 2-3]

The pre-lithiation solution containing the aromatic hydrocarbon derivative represented by the above formula shows an oxidation-reduction potential of 0.2 V or less, and not only has sufficient reducing power for chemical pre-lithiation of a silicon-based anode, but also has an initial coulombic efficiency of more than 100% Could. That is, by successfully compensating for the irreversible lithium loss of the pure SiOx negative electrode, the charge capacity and the discharge capacity have almost the same value.

The solvent of the prelithiation solution may be at least one selected from the group consisting of cyclic ethers and linear ethers, and may preferably be linear ethers. The cyclic ether is dioxolane, methyldioxolane, dimethyldioxolane, vinyldioxolane, methoxydioxolane, ethylmethyldioxolane, oxane, dioxane, trioxane, tetrahydrofuran, methyltetrahydrofuran, dimethyl At least one selected from the group consisting of tetrahydrofuran, dimethoxytetrahydrofuran, ethoxytetrahydrofuran, dihydropyran, tetrahydropyran, hexamethylene oxide, furan, dihydrofuran, dimethoxybenzene and dimethyloxetane The linear ether may be dimethyl ether, diethyl ether, ethyl methyl ether, ethyl propyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, diisobutyl ether, ethyl tertbutyl ether, dimethoxymethane, tri Methoxymethane, dimethoxyethane, diethoxyethane, dimethoxypropane, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol isopropyl methyl ether, diethylene glycol butyl methyl ether, diethylene glycol diethyl ether , from the group consisting of diethylene glycol tertbutyl ethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, ethylene glycol ethyl methyl ether, ethylene glycol divinyl ether, diethylene glycol divinyl ether and triethylene glycol divinyl ether. It may be one or more selected, but is not limited thereto.

The concentration of the complex in the prelithiation solution may be 0.01 to 5 M, preferably 0.1 to 2 M, more preferably 0.2 to 1 M.

The oxidation-reduction potential of the complex may be less than 0.25 V. When it has a redox potential less than the above range, since it has a lower redox potential than a Si/SiOx anode, it has sufficient reducing power and can be suitably used for prelithiation.

Another aspect of the present invention comprises the steps of (a) preparing a negative electrode comprising a negative electrode active material layer formed on one or both surfaces of a current collector; and (b) immersing the negative electrode in a prelithiated solution containing a complex of an aromatic hydrocarbon derivative containing at least one benzene ring having a substituent other than lithium ions and hydrogen to prepare a prelithiated negative electrode; It provides a method for manufacturing a pre-lithiated negative electrode comprising. The manufacturing method of the pre-lithiated negative electrode of the present invention is simple because the pre-lithiated negative electrode is manufactured by immersing the negative electrode in the pre-lithiated solution, and the prepared pre-lithiated negative electrode has a protective layer formed on the electrode surface. Since it is stable for a long time even in dry air, it can be applied to mass production of lithium ion batteries, unlike the existing method that has to meet stringent conditions for prelithiation.

Preferably, the oxidation-reduction potential of the composite may be lower than the oxidation-reduction potential of the negative electrode active material. Based on sufficient reducing power, electrolyte decomposition and unwanted SEI formation reaction after battery assembly are suppressed, and active lithium in the negative electrode is inserted prior to insertion. This is because the lithiation reaction can be promoted and lithium ions can be uniformly inserted into the negative electrode.

The aromatic hydrocarbon derivative may be a polycyclic aromatic compound having 10 to 22 carbon atoms.

The aromatic hydrocarbon derivative may be at least one selected from the group consisting of compounds represented by any one of Chemical Formulas 1 and 2.

[Formula 1]

In Formula 1, R ₁ and R ₂ are the same as or different from each other and are alkyl having 1 to 6 carbon atoms, aryl having 6 to 20 carbon atoms, alkoxy having 1 to 10 carbon atoms, or an alkyl halide having 1 to 6 carbon atoms, a and b are each independently an integer of 0 to 5, at least one is not 0, when a is 2 or more, two or more R ₁ are the same or different from each other, and when b is 2 or more, two or more R ₂ are the same or different from each other,

[Formula 2]

In Formula 2, R ₃ and R ₄ are the same as or different from each other and are alkyl having 1 to 6 carbon atoms, aryl having 6 to 20 carbon atoms, alkoxy having 1 to 10 carbon atoms, or alkyl halide having 1 to 6 carbon atoms, c and d are each other It is independently an integer of 0 to 5, at least one is not 0, when c is 2 or more, two or more R ₃ are the same or different from each other, and when d is 2 or more, two or more R ₄ are the same or different from each other.

The aromatic hydrocarbon derivative may be at least one selected from the group consisting of compounds represented by any one of Formulas 1-1 to 1-3 and 2-1 to 2-3.

[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

[Formula 2-1]

[Formula 2-2]

[Formula 2-3]

The oxidation-reduction potential of the complex may be less than 0.25 V.

The description of the pre-lithiation solution including the complex of lithium ions and aromatic hydrocarbon derivatives is the same as described above in the pre-lithiation solution, and thus will be omitted.

The negative active material is graphite, hard carbon, activated carbon, carbon nanotubes, amorphous carbon, silicon, silicon oxide (SiOx), silicide, silicon alloy, silicon carbide, silicon nitride, Ge, Sn, Sb, Al, Ag, Au And TiO ₂ It may be at least one selected from the group consisting of, preferably at least one selected from the group consisting of carbon, silicon, and silicon oxide. The silicon alloy may be an alloy of at least one metal element selected from Fe, Co, Ni, Ca, Mg, Cu, Al, Ti, and Mn and a silicon element.

The negative active material may serve as an additive or a support for the negative electrode.

The immersion in step (b) may be performed at a temperature of -10 to 80 °C. Preferably it may be carried out at a temperature of 10 to 50 ℃. In the temperature range of -10 to 80 °C, the redox potential of the complex is typically reduced, and the improved reducing power can improve the initial Coulombic efficiency. When it is carried out at a temperature of less than -10 ℃, the oxidation-reduction potential is too high, so that the prelithiation reaction may not occur, and when it is carried out at a temperature of more than 80 ℃, it is not preferable because precipitation of lithium metal may occur. .

The immersion in step (b) may be performed for 0.01 to 1440 minutes, preferably 1 minute to 600 minutes, more preferably 5 to 240 minutes. The initial Coulombic efficiency of the anode manufactured up to 5 minutes after immersion increases rapidly, and the rate of increase gradually decreases from the time point when 30 minutes elapse, and when 120 minutes elapse, the initial Coulombic efficiency does not improve and is maintained . In addition, the open circuit voltage (OCV) of the cell shows a tendency opposite to the initial coulombic efficiency. Therefore, if the immersion time is less than 0.01 minutes, it is difficult to expect the effect of improving the negative electrode performance by prelithiation, and if it exceeds 1440 minutes, no further effects such as improvement of initial Coulombic efficiency or reduction of OCV can be expected. Set an upper limit in the range.

In the negative active material immersed in the prelithiation solution in step (b), the negative active material and the composite of the lithium ion and the aromatic hydrocarbon derivative may have a molar ratio of 1:0.1 to 1:10, preferably It may have a molar ratio of 1:1 to 1:5, more preferably a molar ratio of 1:2 to 1:3. The negative electrode prepared at the molar ratio of 1:0.1 to 1:10 could be completely prelithiated, and the most ideal initial Coulombic efficiency could be achieved at a molar ratio of 1:1 to 1:5.

The step (b) may be continuously performed by a roll-to-roll process. 4F is a view for explaining the roll-to-roll process. In more detail, the roll-to-roll process is performed by a roll-to-roll facility, and the roll-to-roll facility includes an unwinder and a rewinder. The unwinder refers to a portion that continuously unwinds the negative electrode, and the rewinder refers to a portion that continuously winds the negative electrode supplied after the process is completed. The unwinder and the rewinder apply a predetermined tension to the negative electrode for a lithium ion battery. The negative electrode is continuously supplied by the unwinder and the rewinder, and the supplied negative electrode passes through a pre-lithiation solution receiving part accommodating the pre-lithiation solution, and is immersed in the pre-lithiation solution accommodated in the receiving part to pre-lithiate it. Lithium is in progress. The negative electrode that has passed through the pre-lithiation solution receiver is wound by a rewinder. The time immersed in the pre-lithiation solution can be adjusted by adjusting the speed of the roll-to-roll process or by changing the number and position of the rolls. The pre-lithiated negative electrode may pass through an additional solution receiving unit for cleaning and may pass through a drying device to remove residual solution. The prelithiation solution used in the manufacturing method of the present invention forms a protective layer on the surface of the negative electrode to maintain stability for a long time even in a dry atmosphere, so it has the advantage of being applicable to a roll-to-roll process capable of mass production.

Another aspect of the present invention provides a prelithiated negative electrode manufactured according to the above manufacturing method.

Another aspect of the present invention provides a lithium secondary battery including the pre-lithiated negative electrode.

Another aspect of the present invention provides a lithium ion capacitor including the prelithiated negative electrode.

Hereinafter, preferred examples are presented to help the understanding of the present invention. However, these examples are for explaining the present invention in more detail, the scope of the present invention is not limited thereby, and it is common in the art that various changes and modifications are possible within the scope and spirit of the present invention. It will be obvious to those with knowledge.

Example

electrochemical analysis

SiOx (Hansol chemical, Korea), carbon black (Super-P, Timcal, Switzerland), and binder (AST-9005, Aekyung chemical Co., Ltd. Korea) were mixed in a centrifuge (THINKY corporation, Japan) to prepare an electrode-soluble slurry. After casting the slurry on a Cu foil current collector, it was dried at 80° C. for 1 hour, and after roll-pressing, it was cut to a diameter of 11.3 mm (area 1.003 cm ² ) and dried in a vacuum oven at 120° C. overnight. The amount of active material loaded on each electrode was 0.6±0.05 mg/cm ² . The 100 nm size silicon anode was composed of 100 nm Si, carbon black (Super P), and a binder in a weight ratio of 70:18:12. The CR2032 coin cell is a PP/PE/PP separator in an argon atmosphere glove box, and 1 M LiPF ₆ is mixed with ethylene carbonate (EC) and diethyl carbonate (DEC) (1:1 v/v) as an electrolyte. prepared.

The following electrochemical analysis was performed using a WBCS-3000 battery cycler (Wonatech Co. Ltd., Korea) and a VMP3 potentio/galvanostat (Bio-logic Scientific Instruments, France). All electrochemical analyzes were performed at a temperature of 30 °C.

In the half-cell experiment, the coin cell was discharged with a constant current (30 mV vs Li) and a constant voltage until the current density decreased to 10% of the constant current density, and then recharged to 1.2 V. In the first cycle, the second cycle, and the subsequent cycle, the current densities proceeded in steps of 300 mA/g, 600 mA/g and 1500 mA/g, respectively.

In the full-cell experiment, the positive electrode is Li(Ni _1/3 Co _1/3 Mn _1/3 )O ₂ (NCM111) or Li(Ni _0.5 Co _0.2 Mn _0.3 )O ₂ (NCM523) (Wellcos Corporation, Korea), Super P And polyvinylidene fluoride (polyvinylidene fluoride, PvdF) binder in a weight ratio of 84:8:8 N-methyl-2-pyrrolidone (NMP) solvent mixed in a slurry was prepared by casting carbon-coated aluminum foil. The diameters of the positive and negative electrodes were 11.3 mm and 12 mm, respectively. The complete cell is designed so that the N/P ratio (actual cathode to anode capacity ratio) is 1.2. The coin cell was manufactured in the same manner as in the preparation of the half cell, except that a Whatman GFD separator was added.

Cyclic voltammetry for each aromatic hydrocarbon (or aromatic hydrocarbon derivative) compound was performed using copper foil (working electrode), lithium metal (counter electrode) and 0.5 M LiPF at a specified temperature with a scan rate of 50 mV/s. ₆ DME solution was measured using 0.2 M redox-active hydrocarbon as an electrolyte.

Preparation of prelithiation solution

A lithium metal slice was dissolved in a dimethoxyethane solution containing 0.5 M of different aromatic hydrocarbon (or aromatic hydrocarbon derivative) compounds and stirred for 1 hour in a glove box at a temperature of 30 ° C and argon atmosphere to form a lithium-aromatic hydrocarbon (or aromatic hydrocarbon) A prelithiated solution containing the hydrocarbon derivative) compound complex was prepared. In order to supply sufficient lithium, the molar ratio of lithium:aromatic hydrocarbon (or aromatic hydrocarbon derivative) compound was fixed at 4:1. The aromatic hydrocarbon (or aromatic hydrocarbon derivative) compound used above is as follows.

Naphthalene (NP), biphenyl (BP), 3,3'-dimethylbiphenyl (3,3'-dimethylbiphenyl, 3,3'-DMBP), 2-methylbiphenyl (2-methylbiphenyl, 2 -MBP), 4,4'-dimethylbiphenyl (4,4'-dimethylbiphenyl, 4,4'-DMBP), 3,3'4,4'-tetramethylbiphenyl (3,3',4,4 '-tetramethylbiphenyl, 3,3',4,4'-TMBP),

Preparation of prelithiated silicon anode

The SiOx negative electrode was immersed in the prepared pre-lithiation solution for a controlled time and temperature, respectively. After washing with 1 M LiPF ₆ EC/DEC (1:1 v/v) electrolyte, the prelithiated solution and the additional reaction of the negative electrode were quenched to prepare a prelithiated negative electrode. The molar ratio of the lithium-aromatic hydrocarbon (or aromatic hydrocarbon derivative) complex and SiOx in the prelithiation solution was fixed at 6:1.

Experimental Example 1. Pre-lithiation analysis

1A is a cyclic voltammetry analysis result of naphthalene, biphenyl, and methyl-substituted biphenyl used to prepare a pre-lithiated solution according to the above example. As shown in FIG. 1A , it was confirmed through cyclic voltammetry of the aromatic hydrocarbon compound used in the prelithiation solution that the functional group-substituted biphenyl derivatives had lower oxidation-reduction potentials compared to biphenyl. In addition, it was confirmed that naphthalene has an oxidation-reduction potential of 0.37 V, which is not suitable for lithiation of SiOx.

In addition, it was confirmed that the degree of change in the redox potential varies depending on the position of the substituent. When one methyl group at the ortho position is substituted (E _1/2 =131 mV, 2-MBP), when two methyl groups are substituted at the meta position (E _1/2 =294 mV, 3,3'-DMBP) ) or when two methyl groups were substituted at the para position (E _1/2 =186 mV for 4,4'-DMBP), it was confirmed that there was a larger potential change. When four methyl groups were substituted at meta and para positions (3,3',4,4'-TMBP), the redox potential was reduced to 129 mV, similar to that of 2-MBP.

In the case of two methyl groups substituted at the ortho position (2,2'-DMBP), it was confirmed that it had a reduction potential of 0 V vs Li/Li ⁺ or less, and lithium metal 2,2'-DMBP prelithiated solution was found to be stable.

The reduction in the reduction potential is associated with an increase in frontier molecular orbital energy level as a result of chemical functional group substitution.

Figure 1b is a graph showing the correlation between the calculated LUMO energy and redox potential (redox potential, E _1/2 ). As shown in FIG. 1b, the LUMO (lowest unoccupied molecular orbital) energy level of the functional group-substituted biphenyl derivatives is the density functional theory calculation (DFT calculation) result of the experimentally observed slope of the redox potential. -1.01 V eV ^-1 was a linear agreement. Using the LUMO energy of -0.11 eV of 2,2'-DMBP, the redox potential of -0.25 V vs Li/Li ⁺ was calculated based on extrapolation, which means that this complex is less stable than that of lithium metal. did

1C is a result of analyzing the correlation between the oxidation-reduction potential and the initial Coulombic efficiency of the electrode manufactured according to the above embodiment. The reduction potentials of 4,4'-DMBP, 2-MBP, and 3,3',4,4'-TMBP, which are biphenyl derivatives substituted with functional groups, were 0.2 V or less, and 107% and 124% exceeding 100%, respectively. and an initial coulombic efficiency of 118%. On the other hand, other electrodes with high reduction potential had limited improvement. The initial coulombic efficiency of the functional group-substituted biphenyl derivative was proportional to the decrease in E _1/2 , which proved that the degree of prelithiation could be changed according to the molecular formula of the lithium-aromatic hydrocarbon compound complex. Also, as shown in FIG. 1d , 4,4'-DMBP with E _1/2 of 0.19 V showed 1483 mAh/g with the same discharge capacity as the charge capacity, and irreversible generated during the initial discharge of the prelithiated SiOx negative electrode. It was confirmed that the lithium loss was successfully compensated for. 1D is a voltage profile of the first charge-discharge cycle of a SiOx cathode and a pure SiOx electrode prelithiated with 4,4'-DMBP.

To determine the active lithium content after prelithiation of SiOx, the delithiation capacity was measured by directly charging a prelithiation-SiOx||Li cell (Fig. 1e). 1E is a graph showing the electrochemical titration of the amount of active lithium ions stored in the SiOx electrode after prelithiation. As shown in FIG. 1e, the charging capacity of the electrodes immersed in the 4,4'-DMBP, 2-MBP, and 3,3',4,4'-TMBP prelithiation solution was 312 mAh g ^-1 , respectively. 518 mAh g ^-1 and 560 mAh g ^-1 corresponded to 21-37% of the reversible capacity of SiOx. On the other hand, the NP-, BP- and 3,3'-DMBP-prelithiated electrodes had very small charge capacity due to lack of reducibility to add lithium to SiOx. Therefore, it can be seen that the improvement of the initial Coulombic efficiency according to the NP, BP, and 3,3'-DMBP prelithiation solution treatment shown in FIG. 1c is due to the formation of an SEI layer on the surface of SiOx to suppress unwanted side reactions. Therefore, from the above results, in order to achieve an ideal Coulombic efficiency by allowing SiOx to accept active lithium, in contrast to the preformation of SEI by a lithium-aromatic hydrocarbon compound complex with insufficient reducing power, an aromatic hydrocarbon compound substituted with a functional group was used. It was confirmed that the lithium-aromatic hydrocarbon derivative complex including the essential is essential.

Experimental Example 2. Control of prelithiation temperature and time

A pre-lithiated electrode was prepared by controlling the temperature and time of the pre-lithiation reaction using the 4,4'-DMBP pre-lithiation solution.

First, cyclic voltammetry was performed to measure the temperature coefficient (α=dE _1/2 /dT) of the 4,4'-DMBP prelithiation solution, and thermodynamically 4,4'- The reducing power of the DMBP prelithiation solution was adjusted. Figure 2a is a graph showing the relationship between the redox potential and temperature of 4,4'-DMBP. As shown in Fig. 2a, E _1/2 of the 4,4'-DMBP prelithiated solution is linear from 231 mV to 129 mV with a slope of -2.6 mV/K as the temperature increases from 10 °C to 50 °C. changed negatively. The calculated entropy and enthalpy of the redox reaction were -248.9 J mol ^-1 K ^-1 and -92.5 KJ mol ^-1 , respectively. Therefore, the prelithiation solution theoretically does not precipitate lithium metal at a temperature below 95.7 °C where the E _1/2 value reaches 0 V (vs Li/Li + ). It can be seen from FIG. 2b that the initial coulombic efficiency of prelithiated SiOx improved from 103% to 142% as the reducing power was improved by increasing the temperature from 30°C to 50°C. 2B is an initial voltage profile of an SiOx anode manufactured by varying the prelithiation time.

2c and 2d are results of measuring the initial coulombic efficiency, open circuit voltage, and voltage profile according to the prelithiation time. It was confirmed that the precipitation time also had a significant effect on the degree of prelithiation of the SiOx electrode. The lithiation reaction within a few minutes significantly improved the initial coulombic efficiency of the SiOx electrode. After a precipitation time of 5 minutes, the initial coulombic efficiency increased from 57% to 91%, which is similar to that of a commercial anode. After 30 minutes, the initial coulombic efficiency reached 100%, the reaction rate of prelithiation decreased, and finally reached an equilibrium state after 2 hours.

From the above results, it was confirmed that by adjusting the prelithiation temperature and time, it is possible to precisely control the degree of prelithiation, which can easily realize industrial scale application.

The open circuit voltage (OCV) of the SiOx||Li cell was measured immediately after cell assembly was completed to predict the degree of prelithiation before cycling, and the results are shown in FIG. 2C. The OCV showed a difference of only 20 mV according to the change of the prelithiation reaction time of 10 hours, which means that lithium was uniformly accommodated in SiOx during solution-based prelithiation.

Experimental Example 3. Chemical change and microstructure change of SiOx electrode during prelithiation reaction

chemical change analysis

In order to confirm the chemical change of SiOx during the prelithiation reaction, X-ray photoelectron spectroscopy (XPS) analysis was performed. 3a is a Li 1s spectrum XPS analysis result of a pure electrode and a prelithiated electrode. 3a, the prelithiated electrode shows a clear peak at 56 eV, which is due to the Li dopant present in Li _y SiO _x /Li _z Si and Li in the formed SEI layer. The C 1s spectrum also detects SEI components including CO and OC=O, and partially prelithiated carbon black is observed in the electrode. In the Si 2p spectrum of FIG. 3b , it can be seen that pure SiOx has 99.5 eV and 103 eV peaks corresponding to Si and SiOx, respectively. Additional peaks after prelithiation are observed at 98.5 eV and 101.8 eV, which are peaks for prelithiated Si and SiOx, respectively.

In addition, the chemical state of the lithium-aromatic hydrocarbon derivative compound complex solution before and after immersion of the SiOx negative electrode was analyzed. The main chemical species present in the lithium-aromatic hydrocarbon derivative compound complex solution at room temperature is a biphenyl derivative radical ion substituted with each functional group, and during prelithiation, Li ⁺ -[4,4' ^- DMBP] -complex is lithium It was expected that the electrons of the ions migrate to the SiOx electrode and reoxidize to neutral 4,4'-DMBP. In order to prove this hypothesis, the FT-IR spectra of the 4,4'-DMBP solution, the Li ⁺ -[4,4'-DMBP] ^-composite solution, and the composite solution after immersion of the SiOx electrode were compared (Fig. 3c). . Figure 3c shows DME, 4,4'-DMBP, Li-4,4'-DMBP (LAC), Li after reacting with SiOx electrode by varying the loading amount of Li:Si=3:1 a and 1:1 FT-IR spectrum of -4,4'-DMBP (LAC+SiOx) solution. From the FT-IR spectrum, it was clearly observed that 4,4'-DMBP was first reduced and then reoxidized when lithium metal and SiOx electrode successfully reacted (the characteristic peak of 4,4'-DMBP) 806 and 1502 cm ^-1 disappeared after lithium was added, and were regenerated after reaction with SiOx). These results prove the reversible redox reaction of 4,4'-DMBP, and indicate the possibility of reuse of the pre-lithiation reaction of the lithium-aromatic hydrocarbon derivative compound complex.

3d is an expected FT-IR spectrum of neutral and radical anions of 4,4'-DMBP showing the expected vibration frequency of 4,4'-DMBP through DFT calculation. The 806 and 1502 cm ⁻¹ peaks indicate out-of-plane CH bending and elongation of the benzene ring CC at 4,4′-DMBP, respectively. The new peaks at 737, 758 and 1580 cm ⁻¹ indicate in-plane CC bending, out-of-plane CC bending and CC elongation of the benzene ring, respectively, consistent with the calculated vibrational frequencies of the Li-4,4′-DMBP complex radical anion. . The results according to the above DFT calculations demonstrate that 4,4'-DMBP is capable of complex formation and reversible formation of phenyl in the subsequent prelithiation.

When the lithium-aromatic hydrocarbon derivative compound complex was reacted with SiOx at 1/3 molar equivalent, the characteristics of the Li-4,4'-DMBP complex solution and the 4,4'-DMBP solution were mixed, and it was observed that neutral and anion It meant that 4,4'-DMBP in the form was present. Conversely, when reacted with the same molar equivalent, the spectrum was the same as that of the 4,4'-DMBP solution, meaning that prelithiation completely oxidized the lithium-aromatic hydrocarbon derivative compound complex. In this case, the initial coulombic efficiency of the prelithiated SiOx negative electrode was partially improved, because the lithium-aromatic hydrocarbon derivative compound composite was insufficient to achieve the ideal initial coulombic efficiency. Since the initial coulombic efficiency and the lithium-aromatic hydrocarbon derivative compound complex:SiOx molar ratio have a linear proportional relationship, it was confirmed that the lithium-aromatic hydrocarbon derivative compound complex having 2.5 molar equivalents was most ideal for the electrode. Also, as shown in FIG. 3e , when the lithium-aromatic hydrocarbon derivative compound solution reacted more than the same equivalent of SiOx, it was confirmed that the color change from blue to green occurred.

Analysis of microstructural changes

3G is a cross-sectional SEM image of a pure SiOx anode and a prelithiated SiOx anode according to an embodiment of the present invention, and FIG. 3H is a pure Si cathode and a prelithiated Si anode including Si particles having a size of 100 nm. This is a cross-sectional SEM image. As a result of the chemical lithiation of SiOx, it was confirmed from the SEM image of FIG. 3g that the volume of the active particles expanded and filled the original pores. The unique characteristics of SiOx nanoflakes disappeared as they merged with other adjacent particles, and the pores, which accounted for 20.1% of the designated observed area, rapidly decreased to 11.1% after prelithiation. As shown in the histogram of Fig. 3f, mainly a small number of small pores decreased. Also, as can be seen in FIG. 3h , in the electrode including 100 nm-sized Si particles, pore shrinkage was also observed due to uniform expansion of the entire electrode particle, and at the same time, the thickness of the electrode was 7.85 due to prelithiation. increase could be observed.

The advantage of solution-based prelithiation over physical/mechanical methods is that a spatially uniform reaction occurs. Silicon particles with a size of 100 nm exhibited the same volume expansion after prelithiation due to spatially uniform lithiation. In order to check whether the penetration of the lithium-aromatic hydrocarbon derivative compound solution occurs effectively, prelithiation of a thick SiOx electrode with a large areal capacity (2.46 mAh cm ^-2 ) was performed, and 104% of the initial Coulombic efficiency was achieved. Under the same conditions, the thin electrode showed 108% of the initial coulombic efficiency, which means that the prelithiation operation of the present invention can alleviate the pressure problem inside the battery.

Experimental Example 4. Lithium-ion battery production applicability experiment

full cell test

As the initial coulombic efficiency of the SiOx anode improved, the energy density of the full cell including the prelithiated anode was improved.

4A is an initial electrochemical cycle voltage profile of LiNi _0.5 Mn _0.3 Co _0.2 O ₂ (hereinafter, NMC532)||bare SiOx full cell (hereinafter, NBFC) and NMC532||prelithiated SiOx full cell (hereinafter, NPFC). As shown in FIG. 4a, the charging profile of the NPFC showed a higher voltage and lower capacity than the NBFC. The discharge profile of NPFC showed a significant energy density improvement compared to that of NBFC, because the reversible capacity was increased by the excess active lithium present following prelithiation. NBFC of 75.6 mAh g ^-1 In the discharge capacity and 4.2-2.0 V cycle, the initial coulombic efficiency was 37.8%, whereas the NPFC showed 163 mAh g-1 and 86.4% initial efficiency. In addition, in FIG. 4a, the energy densities of NPFC and NBFC were 504.1 and 233.6 Wh kg-1, respectively, and it was confirmed that the pre-lithiated anode improved the energy density of the full cell by 116%.

4B is a voltage profile of the initial cycle of a full cell with a prelithiated SiOx cathode and a full cell with a conventional graphite anode. As shown in FIG. 4b, it was confirmed that the full cell including the pre-lithiated SiOx negative electrode had an improved energy density of 98.2 Wh kg ^-1 compared to the conventional full cell including the graphite negative electrode.

In addition, voltage profiles of the positive and negative electrodes of NBFC and NPFC were measured using a three-electrode cell having lithium metal as a reference electrode. Fig. 4c is anode and cathode voltage profile of NBFC, and Fig. 4d is anode and cathode voltage profile of NPFC. As shown in FIGS. 4c and 4d , during charging of the NBFC, the SiOx cathode first undergoes an electrochemical reaction to form an SEI at 0.5 V, which leads to a drop in the cell voltage (voltage difference between the anode and the cathode). At the last stage of charging, the voltage of the NBFC SiOx cathode was 0.14 V, which was higher than that of the NPFC, 0.08 V. Therefore, with a cell voltage of 4.2 V, NBFC showed a positive voltage of 4.34 V, while NPFC showed 4.26 V. The high anode voltage of NPFC causes delithiation of NMC532, and the high charging voltage causes overcharge of NMC532. During the discharge process, the cell voltage of NBFC was rapidly decreased due to the low coulombic efficiency of SiOx. When the cell voltage reached the cut-off voltage of 2.0 V, the cathode voltage was 1.83 V and the anode voltage was 3.83 V. This result means that the negative electrode limits further discharge of the NBFC, as the positive electrode is still capable of further lithiation up to 3.6 V. In contrast, since the cathode potential of the NPFC was kept below 0.55 V, the full capacity of the anode could be used. Therefore, it could be confirmed from the above results that a high-capacity negative electrode through prelithiation is essential for achieving high energy density of a lithium-ion battery.

Dry Air Stability Assessment

The anode prelithiated according to the present invention showed adequate stability in a dry air atmosphere. Conventional chemical prelithiation had a problem of instability due to the high reactivity of the anode lithiated with suppository.

4E is a result of measuring the initial coulombic efficiency, OCV, and electrode profile according to the dry air exposure time of the prelithiated SiOx anode according to an embodiment of the present invention.

Dry air stability evaluation was conducted in a drying room with a dew point of -86.6 °C. The SiOx anode was first prelithiated at 30° C. for 90 minutes, and then vacuum dried for 3 minutes. After exposure to dry atmosphere for 5, 15, 30 and 60 minutes, the prelithiated negative electrode was washed with electrolyte in a glove box under argon atmosphere.

As shown in FIG. 4E, the initial coulombic efficiency of the prelithiated negative electrode according to the present invention was close to 100% even after exposure to dry air for 1 hour, and the overvoltage increased very slightly. This excellent stability in a dry atmosphere is due to the formation of a protective layer on the surface of the prelithiated negative electrode. Based on such excellent dry air stability, the solution-based prelithiation method of the present invention can be easily applied to the continuous roll-to-roll process shown in FIG. It is possible.

Experimental Example 5. Application of other aromatic hydrocarbon derivatives

In order to confirm the applicability of aromatic hydrocarbons other than biphenyl, a prelithiated SiOx negative electrode was prepared in the same manner as in the above example using a prelithiated solution containing a complex of lithium ions and a naphthalene derivative. The types of naphthalene derivatives used are as follows.

2-methylnaphthalene (2-methylnaphthanlene, 2-MNP), 1,2-dimethylnaphthalene (1,2-DMNP), 1,4,6,7-tetramethylnaphthalene (1,4, 6,7-tetramethylnaphthalene, 1,4,6,7-TMNP)

In addition, the coulombic efficacy and OCV of the prepared negative electrode were measured. 5 is a result of measuring OCV, and FIG. 6 is a result of measuring Coulombic efficiency.

As shown in FIG. 5, the OCV of the pre-lithiated SiO electrode was significantly reduced compared to that of the non-pre-lithiated pure SiO electrode (Pristine SiO), and when a lithium-naphthalene composite (Prelithiated with NP) was used, On the other hand, in the case of the negative electrode (Prelithiated with 2-MNP, Prelithiated with 1,2-DMNP, Prelithiated with 1,4,6,7-TMNP) using the lithium-naphthalene derivative complex prelithiation solution, the OCV is higher. decrease could be observed.

In addition, as shown in FIG. 6, it was confirmed that the case of using the naphthalene derivative also showed a similar tendency to the case of the biphenyl derivative of Experimental Examples 1 and 2. The negative electrode pre-lithiated using the lithium-naphthalene complex pre-lithiation solution had a coulombic efficiency of 84%, whereas the negative electrode pre-lithiated using the lithium-naphthalene derivative complex pre-lithiation solution had an improved Coulombic efficiency. was able to confirm that In particular, in the case of the lithium ion and 1,4,6,7-TMNP complex and the lithium ion and 1,2-DMNP complex, it was confirmed that the coulombic efficiency was significantly increased, such as exceeding 100%.

Therefore, the pre-lithiation solution and the method for manufacturing the pre-lithiated negative electrode using the same according to the present invention are through a simple process of immersing the negative electrode in the solution using the pre-lithiated solution having a sufficiently low oxidation-reduction potential compared to the negative electrode active material. Lithium ions can be uniformly intercalated throughout the negative electrode chemically in the solution phase, and a high level of prelithiation can be achieved. The pre-lithiated negative electrode prepared by the above method has an ideal initial coulombic efficiency, and a lithium ion battery having a high energy density can be manufactured based on this. In addition, the prepared negative electrode has an advantage suitable for mass production based on excellent stability even in a dry atmosphere.

The above-described Examples and Comparative Examples are examples for explaining the present invention, and the present invention is not limited thereto. Those of ordinary skill in the art to which the present invention pertains will be able to practice the present invention with various modifications therefrom, so the technical protection scope of the present invention should be defined by the appended claims.

Claims (23)

(a) a complex of an aromatic hydrocarbon derivative containing at least one benzene ring having a substituent other than lithium ion and hydrogen; and
(b) dioxolane, methyldioxolane, dimethyldioxolane, vinyldioxolane, methoxydioxolane, ethylmethyldioxolane, oxane, dioxane, trioxane, tetrahydrofuran, methyltetrahydrofuran, dimethyltetrahydro At least one cyclic type selected from the group consisting of furan, dimethoxytetrahydrofuran, ethoxytetrahydrofuran, dihydropyran, tetrahydropyran, hexamethylene oxide, furan, dihydrofuran, dimethoxybenzene and dimethyloxetane Ether solvent or dimethyl ether, diethyl ether, ethyl methyl ether, ethyl propyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, diisobutyl ether, ethyl tertbutyl ether, dimethoxymethane, trimethoxymethane , dimethoxyethane, diethoxyethane, dimethoxypropane, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol isopropyl methyl ether, diethylene glycol butyl methyl ether, diethylene glycol diethyl ether, diethylene 1 selected from the group consisting of glycol tertbutyl ethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, ethylene glycol ethyl methyl ether, ethylene glycol divinyl ether, diethylene glycol divinyl ether and triethylene glycol divinyl ether A prelithiation solution comprising at least one linear etheric solvent.
The method of claim 1,
The aromatic hydrocarbon derivative is a pre-lithiated solution of a polycyclic aromatic compound having 10 to 22 carbon atoms excluding the substituent.
According to claim 1,
The aromatic hydrocarbon derivative is a prelithiation solution of at least one selected from the group consisting of compounds represented by any one of the following Chemical Formulas 1 and 2:
[Formula 1]

In Formula 1, R ₁ and R ₂ are the same as or different from each other and are alkyl having 1 to 6 carbon atoms, aryl having 6 to 20 carbon atoms, alkoxy having 1 to 10 carbon atoms, or an alkyl halide having 1 to 6 carbon atoms,
a and b are each independently an integer of 0 to 5, at least one of which is not 0,
When a is 2 or more, two or more R ₁ are the same as or different from each other,
When b is 2 or more, two or more R ₂ are the same as or different from each other,
[Formula 2]

In Formula 2, R ₃ and R ₄ are the same as or different from each other and are alkyl having 1 to 6 carbon atoms, aryl having 6 to 20 carbon atoms, alkoxy having 1 to 10 carbon atoms, or an alkyl halide having 1 to 6 carbon atoms,
c and d are each independently an integer of 0 to 5, at least one of which is not 0,
When c is 2 or more, two or more R ₃ are the same as or different from each other,
When d is 2 or more, 2 or more R ₄ are the same as or different from each other.
4. The method of claim 3,
In Formula 1, R ₁ and R ₂ are the same as or different from each other and are alkyl having 1 to 4 carbon atoms,
a and b are each independently an integer of 0 to 2, at least one of which is not 0,
When a is 2 or more, two or more R ₁ are the same as or different from each other,
When b is 2 or more, two or more R ₂ are the same as or different from each other,
In Formula 2, R ₃ and R ₄ are the same as or different from each other and are alkyl having 1 to 4 carbon atoms,
c and d are each independently an integer of 0 to 2, at least one of which is not 0,
When c is 2 or more, 2 or more R ₃ are the same as or different from each other,
When d is 2 or more, two or more R ₄ are the same or different from each other in a prelithiated solution.
The method of claim 1,
The aromatic hydrocarbon derivative is a prelithiated solution of at least one selected from the group consisting of compounds represented by any one of the following Chemical Formulas 1-1 to 1-3 and 2-1 to 2-3:
[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

[Formula 2-1]

[Formula 2-2]

[Formula 2-3]

According to claim 1,
The concentration of the complex in the pre-lithiation solution is 0.01 to 5 M pre-lithiation solution.
According to claim 1,
The redox potential of the complex is less than 0.25 V prelithiated solution.
(a) preparing a negative electrode comprising a negative electrode active material layer formed on one or both surfaces of the current collector; and
(b) preparing a prelithiated negative electrode by immersing the negative electrode in a prelithiated solution containing a complex of an aromatic hydrocarbon derivative containing at least one benzene ring having a substituent other than lithium ions and hydrogen; A method for manufacturing a pre-lithiated negative electrode.
9. The method of claim 8,
The oxidation-reduction potential of the composite is lower than the oxidation-reduction potential of the negative electrode active material.
9. The method of claim 8,
Wherein the aromatic hydrocarbon derivative is a polycyclic aromatic compound having 10 to 22 carbon atoms excluding the substituent.
9. The method of claim 8,
The aromatic hydrocarbon derivative is at least one selected from the group consisting of compounds represented by any one of the following Chemical Formulas 1 and 2:
[Formula 1]

In Formula 1, R ₁ and R ₂ are the same as or different from each other and are alkyl having 1 to 6 carbon atoms, aryl having 6 to 20 carbon atoms, alkoxy having 1 to 10 carbon atoms, or an alkyl halide having 1 to 6 carbon atoms,
a and b are each independently an integer of 0 to 5, at least one of which is not 0,
When a is 2 or more, two or more R ₁ are the same as or different from each other,
When b is 2 or more, two or more R ₂ are the same as or different from each other,
[Formula 2]

In Formula 2, R ₃ and R ₄ are the same as or different from each other and are alkyl having 1 to 6 carbon atoms, aryl having 6 to 20 carbon atoms, alkoxy having 1 to 10 carbon atoms, or an alkyl halide having 1 to 6 carbon atoms,
c and d are each independently an integer of 0 to 5, at least one of which is not 0,
When c is 2 or more, two or more R ₃ are the same as or different from each other,
When d is 2 or more, 2 or more R ₄ are the same as or different from each other.
12. The method of claim 11,
In Formula 1, R ₁ and R ₂ are the same as or different from each other and are alkyl having 1 to 4 carbon atoms,
a and b are each independently an integer of 0 to 2, at least one of which is not 0,
When a is 2 or more, two or more R ₁ are the same as or different from each other,
When b is 2 or more, two or more R ₂ are the same as or different from each other,
In Formula 2, R ₃ and R ₄ are the same as or different from each other and are alkyl having 1 to 4 carbon atoms,
c and d are each independently an integer of 0 to 2, at least one of which is not 0,
When c is 2 or more, 2 or more R ₃ are the same as or different from each other,
When d is 2 or more, R ₄ or more is the same as or different from each other.
9. The method of claim 8,
The aromatic hydrocarbon derivative is at least one selected from the group consisting of compounds represented by any one of the following Chemical Formulas 1-1 to 1-3 and 2-1 to 2-3 Method for preparing a prelithiated negative electrode:
[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

[Formula 2-1]

[Formula 2-2]

[Formula 2-3]

9. The method of claim 8,
The oxidation-reduction potential of the composite is less than 0.25 V method of manufacturing a pre-lithiated negative electrode.
9. The method of claim 8,
The negative active material is graphite, hard carbon, activated carbon, carbon nanotubes, amorphous carbon, silicon, silicon oxide (SiOx), silicide, silicon alloy, silicon carbide, silicon nitride, Ge, Sn, Sb, Al, Ag, Au And TiO ₂ A method of manufacturing at least one prelithiated negative electrode selected from the group consisting of.
16. The method of claim 15,
The negative electrode active material is a method of manufacturing a pre-lithiated negative electrode, characterized in that performing the function of an additive or support of the negative electrode.
9. The method of claim 8,
The immersion in step (b) is a method for producing a pre-lithiated negative electrode is performed at a temperature of -10 to 80 ℃.
9. The method of claim 8,
The immersion in step (b) is a method of manufacturing a pre-lithiated negative electrode is performed for 0.01 to 1440 minutes.
9. The method of claim 8,
The ratio of the negative electrode active material immersed in the prelithiation solution in step (b) is, the composite to the negative electrode active material has a molar ratio of 1:0.1 to 1:10. Method of manufacturing a pre-lithiated negative electrode.
9. The method of claim 8,
The step (b) is a method of manufacturing a pre-lithiated negative electrode that is performed continuously by a roll-to-roll process.
21. A prelithiated negative electrode manufactured according to the method of any one of claims 8 to 20.
A lithium secondary battery comprising the pre-lithiated negative electrode of claim 21.
A lithium ion capacitor comprising the prelithiated negative electrode of claim 21 .

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