KR102195049B1 - Electrode structure comprising barrier layer, and method of fabricating of the same - Google Patents

Abstract

An electrode structure is provided. The electrode structure includes a base electrode having a convex portion and a concave portion, and covers the convex portion of the base electrode, exposes the concave portion of the base electrode, and includes a lithium non-reactive material. It may include a barrier layer (barrier layer).

Description

Electrode structure comprising barrier layer, and method of fabricating of the same}

The present invention relates to an electrode structure having a barrier layer, and a method of manufacturing the same, and more particularly, to an electrode structure including a barrier layer covering a convex portion of a base electrode, and a method of manufacturing the same.

With the development of portable mobile electronic devices such as smartphones, MP3 players, and tablet PCs, the demand for secondary batteries capable of storing electrical energy is exploding. In particular, with the advent of electric vehicles, medium and large-sized energy storage systems, and portable devices requiring high energy density, demand for lithium secondary batteries is increasing.

For example, Korean Patent Laid-Open Publication No. 10-2017-0076228 includes a silicate oxide and a titanium dioxide coating layer positioned on the surface of the silicon oxide, but the content of the titanium dioxide coating layer is 2 to 10% by weight based on 100% by weight of the total negative active material. %, a negative active material for a lithium secondary battery is disclosed.

In addition, as another example, in Korean Patent Laid-Open Publication No. 10-2017-0036381, _a silicon-based composite represented by SiO _a (a is 0=y<1), and the silicon-based composite includes meso pores and macropores. A lithium secondary battery with improved initial capacity and efficiency, and a method of manufacturing the same, using an anode active material having a bimodal pore structure including (macro pores) are disclosed.

One technical problem to be solved by the present invention is to provide a high-efficiency lithium secondary battery and a method for manufacturing the same.

Another technical problem to be solved by the present invention is to provide a long-life lithium secondary battery and a method for manufacturing the same.

Another technical problem to be solved by the present invention is to provide a high-capacity lithium secondary battery and a method of manufacturing the same.

Another technical problem to be solved by the present invention is to provide a lithium secondary battery with minimized dendrite formation and a manufacturing method thereof.

Another technical problem to be solved by the present invention is to provide a lithium secondary battery with improved electrodeposition density and a method for manufacturing the same.

The technical problem to be solved by the present invention is not limited to the above.

In order to solve the above technical problem, the present invention provides an electrode structure.

According to an embodiment, the electrode structure includes a base electrode having a convex portion and a concave portion, and covers the convex portion of the base electrode, exposes the concave portion of the base electrode, and includes a lithium non-reactive material. It may include a barrier layer containing a non-reactive material).

According to an embodiment, an area ratio of the concave portion may be larger than an area ratio of the convex portion.

According to an embodiment, irregularities may be provided on the exposed surface of the concave portion.

According to an embodiment, the barrier layer may include at least one of an organic polymer, a metal, an oxide, or a ceramic.

According to an embodiment, the base electrode may contain lithium.

In order to solve the above technical problem, the present invention provides a lithium secondary battery.

According to an embodiment, the rechargeable lithium battery may include a negative electrode including an electrode structure according to the above-described embodiment, a positive electrode, and an electrolyte between the negative electrode and the positive electrode.

In order to solve the above technical problem, the present invention provides a method of manufacturing an electrode structure.

According to an embodiment, the method of manufacturing the electrode structure includes preparing a base electrode, forming a convex portion and a concave portion on a surface of the base electrode, and covering the convex portion of the base electrode, It may include the step of exposing the recess and forming a barrier layer including a lithium non-reactive material.

According to an embodiment, the forming of the convex portion and the concave portion includes preparing a master substrate having a protruding portion and a concave portion, and bonding the master substrate and the base electrode to the concave portion corresponding to the protruding portion. And forming the convex portion corresponding to the depression.

According to an embodiment, the preparing of the master substrate includes providing a source material of the barrier layer in the depression of the master substrate, and the master substrate and the base electrode are bonded to each other, and the depression is The source material within may be transferred onto the protrusion.

According to an embodiment, the providing of the source material in the recessed portion of the master substrate includes providing the source material on the master substrate, and heat treating the master substrate provided with the source material. Can include.

According to an embodiment, the forming of the barrier layer includes preparing a support substrate, providing a source material of the barrier layer on the support substrate, and the source material contacting the convex portion. It may include the step of bonding the support substrate and the base electrode to transfer the source material to the convex portion.

According to an embodiment, the manufacturing of the electrode structure may further include forming the barrier layer, and then etching the exposed surface of the concave portion to form irregularities on the surface of the concave portion.

An electrode structure according to an embodiment of the present invention may include a base electrode having a convex portion and a concave portion, and a barrier layer provided on the convex portion and including a lithium non-reactive material. When the barrier layer is provided on the convex portion of the base electrode, the concave portion is exposed, and the electrode structure is used as a negative electrode of a lithium secondary battery, the reversible intercalation of lithium ions at the bottom and side surfaces of the concave portion Since the calation and deintercalation are induced, lithium is deposited in the concave portion, thereby suppressing the formation of dendrites on the surface of the negative electrode and improving the electrodeposition density. For this reason, an electrode structure for a lithium secondary battery having high efficiency, long life, and high reliability can be provided.

1 is a flowchart illustrating a method of manufacturing an electrode structure according to an embodiment of the present invention.
2 is a view for explaining a method of manufacturing an electrode structure according to the first embodiment of the present invention.
3 is a diagram for describing an electrode structure according to a first embodiment of the present invention.
4 is a view for explaining an electrode structure and a method of manufacturing the same according to a second embodiment of the present invention.
5 and 6 are diagrams for explaining an electrode structure and a method of manufacturing the same according to a third embodiment of the present invention.
7 is a diagram for describing a rechargeable lithium battery including an electrode structure according to example embodiments.
8 to 13 are views for explaining the convex portion and the concave portion of the base electrode of the electrode structure according to an embodiment of the present invention.
14 is an image obtained by observing a) a surface and b) a cross section of a lithium metal electrode having a partially protective thin film prepared according to Experimental Example 1-1 of the present invention with an optical microscope.
15 is an image obtained by observing the electrodeposition characteristics during lithium charging according to Experimental Example 2-1 and Comparative Example 2 of the present invention with an optical microscope, and a) is Experimental Example 2-1 and b) is Comparative Example 2.
16 is data obtained by measuring life characteristics and impedance of lithium metal electrodes of Experimental Example 3 and Comparative Example 3 of the present invention.
17 is a block diagram of an electric vehicle according to an embodiment of the present invention.
18 is a perspective view of an electric vehicle according to an embodiment of the present invention.
19 is a view for explaining a battery pack according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the technical idea of the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed content may be thorough and complete, and the spirit of the present invention may be sufficiently conveyed to those skilled in the art.

In the present specification, when a component is referred to as being on another component, it means that it may be formed directly on the other component or that a third component may be interposed between them. In addition, in the drawings, thicknesses of films and regions are exaggerated for effective description of technical content.

In addition, in various embodiments of the present specification, terms such as first, second, and third are used to describe various components, but these components should not be limited by these terms. These terms are only used to distinguish one component from another component. Accordingly, what is referred to as a first component in one embodiment may be referred to as a second component in another embodiment. Each embodiment described and illustrated herein also includes its complementary embodiment. In addition, in the present specification,'and/or' is used to mean including at least one of the elements listed before and after.

In the specification, expressions in the singular include plural expressions unless the context clearly indicates otherwise. In addition, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, elements, or a combination of the features described in the specification, and one or more other features, numbers, steps, and configurations It is not to be understood as excluding the possibility of the presence or addition of elements or combinations thereof.

Further, in the following description of the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

In addition, in the specification of the present application, the term lithium non-reactive material refers to a material that does not substantially undergo a chemical reaction with lithium and lithium ions, and more specifically, a charge/discharge process of a lithium secondary battery It is interpreted as a concept encompassing substances that do not react with lithium ions.

1 is a flowchart illustrating a method of manufacturing an electrode structure according to an exemplary embodiment of the present invention, FIG. 2 is a view illustrating a method of manufacturing an electrode structure according to a first exemplary embodiment of the present invention, and FIG. It is a view for explaining the electrode structure according to the first embodiment of the invention.

1 to 3, a base electrode 200 is prepared. According to an embodiment, the base electrode 200 may contain lithium. Alternatively, according to another embodiment, the base electrode 200 is sodium (Na), magnesium (Mg), aluminum (Al), silicon (Si), indium (In), titanium (Ti), graphite, or carbon It may include at least any one of.

As shown in FIG. 2, the base electrode 200 may be prepared on the current collector 100. For example, the current collector 100 may be a copper foil. The base electrode 200 and the current collector 100 may be thermally laminated and adhered to each other.

The base electrode 200 may include a first surface and a second surface opposite to the first surface. The second surface may contact and adhere to the current collector 100, and the first surface may be exposed. The first surface may be provided in a flat state.

The thickness of the base electrode 200 may be about 1 to 500 μm.

A convex portion 210 and a concave portion 220 may be formed on the surface of the base electrode 200 (S120). Specifically, the convex portion 210 and the concave portion 220 may be formed on the flat first surface of the base electrode 200.

According to an embodiment, as shown in FIG. 2, the forming of the convex portion 210 and the concave portion 220 includes a master substrate 250 having a protrusion 252 and a depression 254 And forming the convex part 210 and the concave part 220 on the first surface of the base electrode 200 by bonding the master substrate 250 and the base electrode 200 It may include the step of. In this case, the convex portion 210 of the base electrode 200 corresponds to the concave portion 254 of the master substrate 250, and the concave portion 220 of the base electrode 200 is the master It may correspond to the protrusion 252 of the substrate 250.

Alternatively, according to another embodiment, the convex portion 210 and the concave portion 220 may be formed by photolithography, molecular self-assembly, electron beam lithography, and dip-pen. ) It can be formed by various methods such as lithography and laser processing technology.

According to an embodiment, on the first surface of the base electrode 200, an area ratio of the concave portion 220 may be larger than an area ratio of the convex portion 210. In other words, on the first surface of the base electrode 200, the area ratio of the bottom surface of the concave part 220 may be greater than the area ratio of the upper surface of the convex part 210.

According to an embodiment, a distance between the upper surface of the convex portion 210 and the bottom surface of the concave portion 220 may be 10% to 90% of the thickness of the base electrode 200.

A barrier layer 300 may be formed to cover the convex portion 210 of the base electrode 200 and expose the concave portion 220 of the base electrode 200. In other words, the barrier layer 300 is selectively provided on the upper surface of the convex portion 210 of the base electrode 200, and the concave portion 220 of the base electrode 200 ) May not be provided on the bottom and side surfaces. Accordingly, the convex portion 210 of the base electrode 200 is blocked from the outside by the barrier layer 300, and the concave portion 220 of the base electrode 200 may be exposed to the outside. .

The barrier layer 300 may include a lithium non reactive material. In other words, the barrier layer 300 may be formed of a material that does not react with lithium, that is, a material in which reversible intercalation and deintercalation of lithium ions are impossible. In addition, when the electrode structure according to the embodiment of the present invention is used for a lithium secondary battery, the barrier layer 300 may be formed of a material that does not react with an electrolyte.

According to an embodiment, the barrier layer 300 may include an organic polymer. For example, the barrier layer 300 is polyethylene, polypropylene, polyvinylidenefluoride (PVDF), vinylidene fluoride-hexafluoropropylene copolymer (PVdF-co-HFP). ), polyimide, polyacrylonitrile, polymethylmethacrylate, polydimethylsiloxane (PDMS), polyisobutylene, polyvinylchloride, poly Vinylidene chloride, polyvinylidene fluoride, polymethylmethacrylate, nylon, polyacrylonitrile, polyviny lalcohol, It may include at least one of polyethylene-co-vinylalcohol, polyethylene terephthalate, polybuthylen eterephthalate, polyester, polyacrylonitrile (PAN), but is not limited thereto. .

Alternatively, according to another embodiment, the barrier layer 300 may include a metal. For example, the barrier layer 300 is chromium (Cr), cesium (Cs), copper (Cu), iron (Fe), hafnium (Hf), manganese (Mn), molybdenum (Mo), sodium (Na) , Niobium (Nb), Nickel (Ni), Aluminum (Al), Titanium (Ti), Barium (Ba), Magnesium (Mg), Boron (B), Yttrium (Y), Zinc (Zn), Calcium (Ca) , Silicon (Si), lead (Pb), strontium (Sr), tin (Sn), vanadium (V), zirconium (Zr), or potassium (K).

According to another embodiment, the barrier layer 300 may include an oxide. For example, the barrier layer 300 is aluminum (Al), titanium (Ti), zirconium (Zr), barium (Ba), magnesium (Mg), boron (B), yttrium (Y), zinc (Zn) , Calcium (Ca), nickel (Ni), silicon (Si), lead (Pb), strontium (Sr), tin (Sn), may be an oxide containing at least one metal of cesium (Cs), the Specific oxides include Al2O3, TiO2, ZrO2, Y2O3, ZnO, CaO, NiO, MgO, SiO2, SiC, Al(OH)3, AlO(OH), BaTiO3, PbTiO3, PZT, PLZT, PMN-PT, HfO2, SrTiO3, SnO3, CeO2, etc. may be mentioned, but the present invention is not limited thereto, and these may be used alone or in combination of two or more. According to another embodiment, the barrier layer 300 may include a ceramic including at least one metal of the above metals.

According to another embodiment, the barrier layer 300 may include a lithium compound. For example, the barrier layer 300 is lithium fluoride (LiF), lithium chloride (LiCl), lithium bromide (LiBr), digested aluminum lithium (LiAlH4) lithium nitride (Li ₃ N), lithium carbonate (Li ₂ CO ₃ ) may be included.

According to another embodiment, the barrier layer 300 may include a carbon material. For example, the barrier layer 300 may include carbon nanotubes (CNTs), carbon fibers, carbon blacks, and graphenes.

According to an embodiment, the providing of the barrier layer 300 on the convex portion 210 includes preparing a flat supporting substrate, and the barrier layer 300 on the supporting substrate Providing a source material, and bonding the support substrate and the base electrode 200 so that the source material contacts the convex portion 210 of the base electrode 200, so that the source material is mixed with the convex portion ( 210) may include the step of transferring. Thereafter, the barrier layer 300 may be formed by irradiating light or performing a heat treatment process on the source material on the convex part 210. Accordingly, the barrier layer 300 may be selectively formed on the convex portion 210. Specifically, for example, a flat PDMS is prepared as the support substrate, the source material is applied on the PDMS, and the PDMS is applied to the base electrode 200 having the convex portion 210 and the concave portion 220. ), the source material may be transferred onto the convex portion 210.

Alternatively, differently from the above, according to another embodiment, the barrier layer 300 may be deposited on the convex portion 210 by using a sputtering process or the like.

As described above, the electrode structure according to the embodiment of the present invention may be used as a negative electrode of a lithium secondary battery, and the barrier layer 300 provided on the convex portion 210 of the base electrode 200 is a lithium ratio. It may contain a reactive material. Accordingly, in the charging/discharging process of the lithium secondary battery, reversible intercalation and deintercalation of lithium ions may not substantially occur in the convex portion 210 of the base electrode 200.

Unlike the above-described embodiments of the present invention, when the negative electrode of the lithium secondary battery has a flat structure or the barrier layer 300 provided on the convex portion 210 is omitted, the charging and discharging process of the lithium secondary battery In the case of intercalation and deintercalation of lithium ions, dendrite may be grown on the surface of the negative electrode, and accordingly, life characteristics and charge/discharge characteristics of the lithium secondary battery may be deteriorated.

However, as described above, according to an embodiment of the present invention, the barrier layer 300 is provided on the convex portion 210 of the base electrode 200, and the concave portion 220 is exposed, The reversible intercalation and deintercalation of lithium ions are induced in the bottom surface and the side of the concave part 220, so that lithium is deposited in the concave part 220, and accordingly, on the negative electrode surface The formation of dendrite can be suppressed and the electrodeposition density can be improved. For this reason, an electrode structure for a lithium secondary battery having high efficiency, long life, and high reliability can be provided.

According to the second embodiment of the present invention, irregularities may be provided in the concave portion 220 of the base electrode 200. Hereinafter, an electrode structure and a manufacturing method thereof according to a second embodiment of the present invention will be described with reference to FIG. 4.

4 is a view for explaining an electrode structure and a method of manufacturing the same according to a second embodiment of the present invention.

Referring to FIG. 4, as described with reference to FIGS. 1 to 3, a current collector 100, a base electrode 200 having a convex portion 210 and a concave portion 220, and the convex portion 210 ), an electrode structure including a barrier layer 300 is provided.

Unlike described with reference to FIGS. 1 to 3, an uneven portion 230 may be provided in the concave portion 220. Specifically, the unevenness 230 may be provided on the bottom and side surfaces of the concave portion 220. Alternatively, unlike FIG. 4, the unevenness 230 may be provided on at least one of the bottom surface or the side surface of the concave book 220.

According to an embodiment, after forming the barrier layer 300 covering the convex portion 210, the uneven portion 230 is formed by etching the bottom surface and the side surface of the concave portion 220. Can be formed. For example, the bottom surface and the side surface of the concave part 220 are etched using an acidic solution (eg, HCl, HF, H ₃ PO ₄ , or HNO ₃ ). Can be.

When the electrode structure according to an embodiment of the present invention is used as a negative electrode of a lithium secondary battery, electrons may be concentrated in the concave and convex 230 formed in the concave portion 220 during a charging and discharging process of the lithium secondary battery. Accordingly, intercalation and deintercalation of lithium ions may be more concentrated on the bottom surface and the side surface of the concave portion 220 on which the irregularities 230 are formed. Accordingly, the formation of dendrites is minimized, and an electrode structure for a lithium secondary battery with improved electrodeposition density may be provided.

Unlike the above-described embodiments of the present invention, according to the third embodiment of the present invention, in one process, the convex portion 210 and the concave portion 220 are formed in the base electrode 200, and the The barrier layer 300 may be formed on the convex portion 210. Hereinafter, an electrode structure and a method of manufacturing the same according to a third embodiment of the present invention will be described with reference to FIGS. 5 and 6.

5 and 6 are diagrams for explaining an electrode structure and a method of manufacturing the same according to a third embodiment of the present invention.

5 and 6, as described with reference to FIGS. 1 to 3, a current collector 100 and a base electrode 200 are prepared, and have a protrusion 252 and a depression 254. The master substrate 250 may be prepared.

A source material 310 of the barrier layer 300 may be provided on the master substrate 250 having the protrusion 252 and the depression 254. According to an embodiment, the source material 310 may be provided on the master substrate 250 in a liquid state or a gel state. The source material 310 may fill the depression 254 of the master substrate 250 and cover the protrusion 252.

The master substrate 250 provided with the source material 310 may be heat treated. Accordingly, the source material 310 is dried, so that the source material 310 may be limitedly provided in the recessed portion 254. In other words, the master substrate 250 may be heat treated so that the source material 310 fills the depression 254 and does not cover the protrusion 252.

Thereafter, as described with reference to FIGS. 1 to 3, by bonding the master substrate 250 and the base electrode 200, the concave portion 220 and the recessed portion corresponding to the protrusion 252 While forming the convex portion 210 corresponding to 254, the source material 310 provided in the concave portion 254 is provided on the convex portion 210 of the base electrode 200, The barrier layer 300 may be formed. In other words, as described with reference to FIGS. 1 to 4, after the convex portion 210 and the concave portion 220 of the base electrode 200 are formed, the barrier is formed on the convex portion 210. The layer 300 is not formed, and the convex portion 210 and the concave portion 220 of the base electrode 200 are formed, and the barrier layer 300 is formed on the convex portion 210. Can be formed. Accordingly, a method of manufacturing an electrode structure with simplified manufacturing processes and reduced manufacturing costs may be provided.

Hereinafter, a lithium secondary battery including the electrode structure according to the exemplary embodiments described above will be described with reference to FIG. 7.

7 is a diagram for describing a rechargeable lithium battery including an electrode structure according to example embodiments.

Referring to FIG. 7, the rechargeable lithium battery may include negative electrodes 100, 200, and 300, positive electrodes 400 and 500, and an electrolyte 600.

The negative electrode (100, 200, 300), the current collector 100 described with reference to FIGS. 1 to 6, a base electrode 200 including a convex portion 210 and a concave portion 220, and the convex A barrier layer 300 on the part 210 may be included.

The positive electrodes 400 and 500 may include a current collector 400 and a positive electrode active material 500 on the current collector 400. The current collector 400 may be a copper foil. The positive electrode active material 500 is LiCoO ₂ , LiNiO ₂ , LiMnO ₂ , LiMn ₂ O ₄ , LiCoPO ₄ , LiNi _x Co _y Mn _z O ₂ (x+y+z=1,0≤x,y,z≤ 1), LiNiCoAlO ₂ It may include a lithium metal oxide such as.

The electrolyte 600 may be disposed between the positive electrodes 400 and 500 and the negative electrodes 100, 200 and 300. According to an embodiment, the electrolyte 600 may be a liquid electrolyte, a polymer electrolyte, or a solid electrolyte. When the electrolyte 600 is the liquid electrolyte and the polymer electrolyte, a lithium salt may be dissolved in a solvent. For example, the lithium salt is LiPF ₆ , LiBF ₄ , LiSbF ₆ , LiAsF ₅ , LiClO ₄ , LiN, CF ₃ SO ₃ , LiN(SO ₂ CF ₃ ) ₂ , LiN(SO ₂ C ₂ F ₅ ) ₂ , LiC(SO ₂ CF ₃ ) ₂ , LiPF ₄ (CF ₃ ) ₂ , LiPF ₃ (C ₂ F ₅ ) ₃ , LiPF ₃ (CF ₃ ) ₃ , LiPF ₅ (iso-C ₃ F ₇ ) ₃ , LiPF ₅ (iso-C ₃ F ₇ ), (CF ₂ ) ₂ (SO ₂ ) ₂ NLi and (CF ₂ ) ₃ (SO ₂ ) ₂ NLi may contain any one or more of at least one lithium salt, which is a liquid electrolyte In the case, the solvent is propylene carbonate, ethylene carbonate (EC), butylene carbonate (BC), ethylmethyl carbonate (EMC), diethyl carbonate, dimethyl Carbonate (dimethylcarbonate, DMC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), methylethyl carbonate (MEC), etc. It can be an organic solvent. In the case of a polymer electrolyte, polyethylene oxide, polypropylene oxide, polyethylene oxide and polypropylene oxide block copolymer; A single polymer containing a silane group and/or a siloxane group, monomethacrylate, vinyl, hydride, distearate, bis(1,2-hydroxy-stearate), methoxy, and a silane group and/or a siloxane group Oxylate, propoxylate, diglycidyl ether, monoglycidyl ether, monohydroxy, bis(hydroxyalkyl), chlorine, bis(3-aminopropyl) and bis((aminoethyl-aminopropyl) dime A copolymer polymer resin including a linking group selected from the group consisting of oxysilyl) ether may be used, or a heterogeneous polymer may be blended. For inorganic electrolytes. _{Cu 3 N, Li 3 N,} LiPON, Li 3 PO 4 .Li 2 S.SiS 2, Li 2 S.GeS 2 .Ga 2 S 3, Li 2 O.11Al 2 O 3, Na 2 O.11Al 2 O ₃ , (Na,Li) _1+x Ti _2-x Al _x (PO ₄ ) ₃ (0.1≤x≤0.9), Li _1+x Hf _2-x Al _x (PO ₄ ) ₃ (0.1≤x≤0.9) ), Na ₃ Zr ₂ Si ₂ PO ₁₂ , Li ₃ Zr ₂ Si ₂ PO ₁₂ , Na ₅ ZrP ₃ O ₁₂ , Na ₅ TiP ₃ O ₁₂ , Na ₃ Fe ₂ P ₃ O ₁₂ , Na ₄ NbP ₃ O ₁₂ , Na-Silicates, Li _0.3 La _0.5 TiO ₃ , Na ₅ MSi ₄ O ₁₂ (M is a rare earth element such as Nd, Gd, Dy) Li ₅ ZrP ₃ O ₁₂ , Li ₅ TiP ₃ O ₁₂ , Li ₃ Fe ₂ P ₃ O ₁₂ , Li ₄ NbP ₃ O ₁₂ , Li _1+x (M,Al,Ga)x(Ge _1-y Ti _y ) _2-x (PO ₄ ) ₃ (X≤0.8, 0≤Y≤1.0, M Is Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm or Yb), Li _1+x+y Q _x Ti _2-x Si _y P _3-y O ₁₂ (0<x≤0.4, 0 <y≤0.6, Q is Al or Ga), Li ₆ BaLa ₂ Ta ₂ O ₁₂ , Li ₇ La ₃ Zr ₂ O ₁₂ , Li ₅ La ₃ Nb ₂ O ₁₂ , Li ₅ La ₃ M ₂ O ₁₂ (M is Nb, or Ta) and Li _7+x A _x La _3-x Zr ₂ O ₁₂ (0<x<3, A is Zn) may be included, but is not limited thereto.

Although not shown in FIG. 7, a separator may be further provided between the anodes 400 and 500 and the cathodes 100, 200 and 300. The separator may be disposed between the anodes 400 and 500 and the cathodes 100, 200, and 300, and may be disposed in the center of the electrolyte 600. According to an embodiment, the separator may include a porous material. For example, the separator) may be a porous film or non-woven fabric made from polyolefin such as polypropylene (PP) or polyethylene (PE).

As described above, the negative electrode for a lithium secondary battery according to an embodiment of the present invention is provided on the convex portion 210 of the base electrode 200 and includes the barrier layer 300 including a lithium non-reactive material. Can include. Accordingly, in the charging/discharging process, reversible intercalation and deintercalation of lithium ions are substantially suppressed in the convex portion 210 and may be intensively generated in the concave portion 220. Accordingly, the formation of dendrites in the negative electrode is minimized, the electrodeposition density is improved, and a lithium secondary battery having high reliability, high efficiency, and long life can be provided.

Hereinafter, various types of convex portions and concave portions of the base electrode of the electrode structure of the present invention will be described with reference to FIGS. 8 to 13.

8 to 13 are views for explaining the convex portion and the concave portion of the base electrode of the electrode structure according to an embodiment of the present invention.

8 to 13, from a three-dimensional perspective, the base electrode 200 includes a convex portion and a concave portion, and a barrier layer 300 is provided on the convex portion, from a two-dimensional perspective, or 3 From a dimensional perspective, the convex portion and the concave portion may be provided in various shapes, as shown in FIGS. 8 to 13.

That is, the technical idea of the present invention for inducing reversible intercalation and deintercalation of lithium ions in the concave by forming the barrier layer 300 on the convex portion of the base electrode 200 is , It is obvious to those skilled in the art that it is not limited to the specific shape of the convex portion and the concave portion, and can be implemented in various shapes and shapes.

Hereinafter, a specific experimental example of a lithium metal electrode having a partially protective thin film according to an embodiment of the present invention will be described. This is for describing the present invention in more detail, and the scope of the present invention is not limited by the experimental examples to be described later.

Experimental Example 1 Preparation of partial protective thin film

Preparation of partial protective thin film according to Experimental Example 1-1

PDMS was prepared as a source material. The PDMS was prepared at a weight ratio of subject: curing agent = 10:1, and coated on the convex portion of lithium metal according to Experimental Example 1-1 through a transfer method to prepare a lithium metal electrode with a partial protective thin film as shown in FIG. And observed with an optical microscope. Red dye was additionally added for easy observation.

Preparation of partial protective thin film according to Experimental Example 1-2

Instead of PDMS in Experimental Example 1-1, PVDF was prepared. The PVDF was prepared at a weight ratio of NMP: PVDF = 9:1, and coated on the convex portion of lithium metal through a transfer method to prepare a partial protective thin film.

Preparation of partial protective thin film according to Experimental Example 1-3

Al- ₂ O ₃ was prepared as a source material. The material was prepared in a weight ratio of NMP: Al- ₂ O ₃ powder = 10:1, and provided as a source material of the barrier layer in the recessed portion of the master substrate. The source material was dried and then coated on the convex portion through a transfer method to prepare a partial protective thin film.

Preparation of partial protective thin film according to Experimental Example 1-4

Instead of Al- ₂ O ₃ in Experimental Example 1-3, TiO- ₂ was prepared. The material was prepared in a weight ratio of NMP: Al- ₂ O ₃ powder = 10:1, and provided as a source material of the barrier layer in the recessed portion of the master substrate. The source material was dried and then coated on the convex portion through a transfer method to prepare a partial protective thin film.

Preparation of partial protective thin film according to Experimental Example 1-5

Cu was prepared as a source material. The material was sputtered to form a partial protective thin film on the convex portion.

Comparative Example 1

A lithium base electrode not coated with a partial protective thin film was used.

The partial protective materials in Experimental Examples 1-1 to 1-5 and Comparative Example 1 of the present invention may be arranged as shown in [Table 1] below.

Partial protection material Experimental Example 1-1 PDMS Experimental Example 1-2 PVDF Experimental Example 1-3 Al ₂ O ₃ Experimental Example 1-4 TiO ₂ Experimental Example 1-5 Cu Comparative Example 1 -

Experiment Example 2

In order to evaluate the lithium electrodeposition characteristics due to the introduction of the partial protective thin film, a 2032 coin cell type battery was manufactured. At this time, the cathode is made of transition metal oxide LiCoO ₂ (KD10, Korea) 90% by weight, conductive material (Super-P, Timcal) 5% by weight, polyvinylidene fluor (PVdF, KF-1300, Kureha) 5% by weight The electrode coating thickness was designed to be 40 μm, and the weight per area was 7.10 mg/cm ² . The electrolyte was a mixture of ethylene carbonate/ethyl methyl carbonate (volume ratio 3/7) (PANAX ETEC Co. Ltd, Korea) containing 1.0 mol/L of lithium salt LiPF ₆ and an organic solvent mixture, a separator. A polyethylene separator (12 μm) was used as the negative electrode, and a lithium metal electrode coated with a partially protective thin film of Experimental Example 1 was used as the negative electrode.

Comparative Example 2

It was carried out in the same manner as in Experimental Example 2, except that a lithium base electrode not coated with a partial protective thin film was used in Experimental Example 2.

The electrodeposition characteristics of Experimental Example 2-1 and Comparative Example 2 are shown in FIG. 15 and observed with an electron microscope. Partial protective materials in Experimental Examples 2-1 to 2-5 and Comparative Example 2 of the present invention may be arranged as shown in [Table 2] below.

Concave wound electrodeposition characteristics Dendrite formation Experimental Example 2-1 Great Good Experimental Example 2-2 Great Good Experimental Example 2-3 Good Good Experimental Example 2-4 Good Good Experimental Example 2-5 Good Good Comparative Example 2 - Bad

15 is data measuring electrodeposition properties of lithium metal electrodes according to Experimental Example 2-1 and Comparative Example 2. From these results, it can be confirmed that lithium electrodeposition properties and dendrite formation are suppressed through the partial protective thin film.

Experiment Example 3

To evaluate the electrochemical properties of lithium due to the introduction of the partial protective thin film, a 2032 coin cell type battery was fabricated. Accordingly, the anode, electrolyte, and separator were performed in the same manner as in Experimental Example 2. Lithium introduced into the PDMS partial protective thin film of Experimental Example 1-1 was used as a negative electrode. The results of Experiment 3 are shown in FIG. 16.

Comparative Example 3

Experimental Example 3 was carried out in the same manner as in Experimental Example 3, except that a lithium base electrode not coated with a partial protective thin film was used.

16 is data obtained by measuring rate speed and impedance characteristics of lithium metal electrodes according to Experimental Example 3 and Comparative Example 3. Specifically, in FIG. 16, a) is a graph showing the results of lifespan characteristics according to charging/discharging at a level of 0.5C, and b) is a graph showing the results of impedance measurement in the initial cycle. From these results, it can be confirmed that improved lifespan characteristics and surface current density control are exhibited through the partial protective thin film coating.

17 is a block diagram of an electric vehicle according to an embodiment of the present invention.

Referring to FIG. 17, an electric vehicle 1000 according to an embodiment of the present invention includes a motor 1010, a transmission 1020, an axle 1030, a battery pack 1040, a power control unit 1050, and a charging unit 1060. ) May include at least one of.

The motor 1010 may convert electric energy of the battery pack 1040 into kinetic energy. The motor 1010 may provide the converted kinetic energy to the axle 1030 through the transmission 1020. The motor 1010 may be formed of a single motor or a plurality of motors. For example, when the motor 1010 includes a plurality of motors, the motor 1010 may include a front wheel motor that supplies kinetic energy to a front axle and a rear wheel motor that supplies kinetic energy to a rear axle.

The transmission 1020 may be positioned between the motor 1010 and the axle 1030 to provide kinetic energy from the motor 1010 to the axle 1030 by shifting to suit the driving environment desired by the driver. have.

The battery pack 1040 may store electric energy from the charging unit 1060 and provide the stored electric energy to the motor 1010. The battery pack 1040 may directly supply electric energy to the motor 1010 or may supply electric energy through the power control unit 1050.

In this case, the battery pack 1040 may include at least one battery cell. In addition, the battery cell may include the lithium secondary battery according to the embodiment of the present invention described above, but is not limited thereto, and may include various types of secondary batteries such as lithium-based secondary batteries. Meanwhile, the battery cell may be a term referring to individual batteries, and the battery pack may refer to an assembly of battery cells in which individual battery cells are interconnected to have a desired voltage and/or capacity.

The power control unit 1050 may control the battery pack 1040. In other words, the power control unit 1050 may control the power from the battery pack 1040 to the motor 1010 to have a required voltage, current, and waveform. To this end, the power control unit 1050 may include at least one of a passive power device and an active power device.

The charging unit 1060 may receive power from the external power source 1070 shown in FIG. 13 and provide it to the battery pack 1040. The charging unit 1060 may generally control a charging state. For example, the charging unit 1060 may control charging on/off and charging speed.

18 is a perspective view of an electric vehicle according to an embodiment of the present invention.

Referring to FIG. 18, the battery pack 1040 may be coupled to the lower surface of the electric vehicle 1000. For example, the battery pack 1040 may have a shape in which the electric vehicle 1000 has a width in a width direction and extends in a length direction of the vehicle 1000. More specifically, the battery pack 1040 may extend from the front suspension to the rear suspension. Accordingly, the battery pack 1040 may provide a space for packaging a larger number of battery cells. In addition, since the battery pack 1040 is coupled to the lower end of the vehicle body, the center of gravity of the vehicle body is lowered, thereby improving the driving safety of the electric vehicle 1000.

19 is a view for explaining a battery pack according to an embodiment of the present invention.

Referring to FIG. 19, the battery pack 1040 may store a plurality of battery cells 1043.

The battery pack 1040 may include a lower housing 1041 and an upper housing 1042. The lower housing 1041 may include a flange 1044, and by fastening a bolt 1045 with the flange 1044 through a hole provided in the upper housing 1045, the lower housing 1041 and the The upper housing 1042 can be coupled.

At this time, in order to improve the stability of the battery pack 1040, the lower and upper housings may be made of a material that can minimize moisture and oxygen penetration. For example, the lower and upper housings may be made of at least one of aluminum, aluminum alloy, plastic, and carbon compound. In addition, an impermeable sealant 1049 may be positioned between the lower housing 1041 and the upper housing 1042.

In addition, the battery pack 1040 may include a component for controlling the battery cell 1043 or improving stability. For example, the battery pack 1040 may include a control terminal 1047 for controlling the battery cell 1043 inside the battery pack 1040. In addition, for example, the battery pack 1040 may include a cooling line 1046 to prevent thermal runaway of the battery cell 1043 or to control the temperature of the battery cell 1043. . Further, for example, the battery pack 1040 may include a gas outlet 1048 for ejecting gas inside the battery pack 1040.

In the above, the present invention has been described in detail using preferred embodiments, but the scope of the present invention is not limited to specific embodiments, and should be interpreted by the appended claims. In addition, those who have acquired ordinary knowledge in this technical field should understand that many modifications and variations can be made without departing from the scope of the present invention.

100: current collector
200: base electrode
210: convex portion
220: recess
230: irregularities
250: master substrate
252: protrusion
254: depression
300: barrier layer
310: source material
400: current collector
500: cathode active material
600: electrolyte

Claims (12)

delete delete delete delete delete delete Preparing a base electrode using lithium metal as a negative electrode;
Forming a convex portion and a concave portion on the surface of the base electrode; And
Covering the convex portion of the base electrode, exposing the concave portion of the base electrode, and forming a barrier layer containing a lithium non-reactive material,
The step of forming the convex portion and the concave portion,
Preparing a master substrate having protrusions and depressions; And
Bonding the master substrate and the base electrode to form the concave portion corresponding to the protruding portion and the convex portion corresponding to the concave portion,
Preparing the master substrate includes providing a source material of the barrier layer in the depression of the master substrate,
The method of manufacturing an electrode structure, comprising bonding the master substrate and the base electrode to transfer the source material in the concave portion onto the convex portion.
delete delete The method of claim 7,
Providing the source material in the depression of the master substrate,
Providing the source material on the master substrate; And
A method of manufacturing an electrode structure comprising the step of heat-treating the master substrate provided with the source material.
delete The method of claim 7,
After forming the barrier layer, the method of manufacturing an electrode structure further comprising the step of etching the exposed surface of the concave portion to form irregularities on the surface of the concave portion.

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