Electrode assembly and rechargeable battery including the same

Abstract

Provided are an electrode assembly for a rechargeable battery and a rechargeable battery including the same, the electrode assembly may include a stack-type electrode assembly in which a positive electrode, a separator, and a negative electrode are alternately stacked, in which the positive electrode is located on the outermost side of the stack-type electrode assembly, and the separator is located on the outermost side of the stack-type electrode assembly. The positive electrode includes a substrate having an electrode uncoated region and an electrode active region, an active material layer formed on one surface of the substrate in the electrode active region, and a ceramic layer formed on an opposite surface of the substrate in the electrode active region, and the one surface is relatively adjacent to the center and faces the negative electrode.

Description

Technical Field

[0001] The embodiments of this disclosure described herein relate to an electrode assembly and a rechargeable battery including the electrode assembly. Background Technology

[0002] Mobile information devices such as cellular phones, laptops, and smartphones have already utilized rechargeable batteries, which have relatively high energy density and are relatively easy to carry, as their power source.

[0003] A rechargeable battery may include an electrode assembly in which a negative electrode, a separator, and a positive electrode are sequentially accumulated, and the positive and negative electrodes may be formed with different areas.

[0004] However, when the areas of the two electrodes are different, the sizes of the active material layers with different polarities may differ, and a short circuit may occur when the exposed substrate and the active material layer with the opposite polarity come into contact with each other. When such a short circuit occurs, a relatively large current flows to one electrode for a short period of time, which may damage the rechargeable battery (e.g., ignition or explosion).

[0005] In addition, when the outermost electrode is the positive electrode, the active material layer of the positive electrode is formed on the outside, and there is no negative electrode facing it, so lithium may precipitate out. Summary of the Invention

[0006] An aspect according to one or more embodiments relates to an electrode that can reduce the risk of short circuits in areas of concentrated current and / or reduce lithium deposition on a positive electrode that does not face the negative electrode, an electrode assembly including the electrode, and a lithium rechargeable battery.

[0007] Other aspects will be set forth in part in the description which follows, and in part will be apparent from the description, or may be learned by practicing the embodiments presented in this disclosure.

[0008] According to one or more embodiments, the electrode assembly for a rechargeable battery may include a stacked (or similar) electrode assembly (e.g., a stacked electrode assembly) in which a positive electrode, a separator, and a negative electrode are alternately stacked, wherein the outermost positive electrode of the stacked (or similar) electrode assembly includes a substrate having an uncoated region and an active region, an active material layer formed on one surface of the substrate in the active region, and a ceramic layer formed on another surface (e.g., a facing surface) of the substrate in the active region, and the one surface is relatively adjacent to the center and faces the negative electrode.

[0009] According to one or more embodiments, a functional layer may also be formed between the substrate and the active material layer.

[0010] According to one or more embodiments, the functional layer may include a first portion superimposed on the electrode active region and a second portion extending from the first portion to the uncoated region of the electrode.

[0011] According to one or more embodiments, the ceramic layer may be formed in a planar shape that is substantially the same as that of the functional layer.

[0012] According to one or more embodiments, the area of ​​the second portion may be equal to or less than about 60% of the area of ​​the uncoated electrode region (e.g., at most about 60% of the total area of ​​the uncoated electrode region).

[0013] According to one or more embodiments, the width of the second portion can be from about 0.1 mm to about 3 mm.

[0014] According to one or more embodiments, the resistance value (e.g., electronic resistance or electrical resistance) of the functional layer may be greater than the resistance value (e.g., electronic resistance or electrical resistance) of the substrate and the active material layer.

[0015] According to one or more embodiments, the boundary of the functional layer may be located within the boundary of the substrate.

[0016] According to one or more embodiments, the functional layer may include a material comprising a compound represented by chemical formula 1, a compound represented by chemical formula 2, or a combination thereof:

[0017] Chemical Formula 1

[0018] Li a1 M 1 x1 Fe 1-x1 PO4

[0019] In chemical formula 1, 0.90 ≤ a1 ≤ 1.5, 0 ≤ x1 ≤ 0.4, M 1 It is Mg, Co, Ni or a combination thereof.

[0020] Chemical formula 2

[0021] Li a2 Mn x2 Fe 1-x2 PO4

[0022] In chemical formula 2, 0.90≤a2≤1.5, 0.1≤x2≤1.

[0023] According to one or more embodiments, the width of the uncoated area of ​​the electrode can be from about 2 mm to about 7 mm.

[0024] According to one or more embodiments, the uncoated area of ​​the electrode may protrude from one side of the active area of ​​the electrode.

[0025] According to one or more embodiments, the distance between the boundary of the positive electrode and the boundary of the negative electrode can be from about 0.5 mm to about 3.0 mm.

[0026] According to one or more embodiments, the rechargeable battery may include the electrode assembly and electrolyte described above.

[0027] According to one or more embodiments, the electrode assembly including the electrode not only reduces the risk of short circuits but also reduces lithium deposition at the outermost positive electrode, thereby providing a relatively safe electrode assembly with improved electrical characteristics and a rechargeable battery including the electrode assembly. Attached Figure Description

[0028] The accompanying drawings are included to provide a further understanding of this disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the disclosure. The above and other aspects, features, and advantages of certain embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0029] Figure 1 It is a top plan view (e.g., a plan view) of the electrodes according to the embodiment;

[0030] Figure 2 It is along Figure 1 A sectional view taken from line II-II';

[0031] Figure 3 This is a schematic exploded perspective view of a stacked (or similar) electrode assembly according to an embodiment;

[0032] Figure 4 This is a schematic cross-sectional view of another stacked (or similar) electrode assembly according to an embodiment; and

[0033] Figure 5 It shows along Figure 1 The cross-sectional view of the positive electrode according to the embodiment is taken from line II-II'. Detailed Implementation

[0034] The present disclosure will be described more fully below with reference to the accompanying drawings, in which exemplary embodiments of the disclosure are illustrated. As will be appreciated by those skilled in the art, the described embodiments may be modified in one or more suitable and different ways without departing from the spirit or scope of the present disclosure. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. As used herein, expressions such as “at least one of…”, “one of…”, and “selected from…” modify the entire list of elements when they follow or precede a list of elements, without modifying individual elements in the list. For example, “at least one of a, b, and c”, “selected from at least one of a, b, and c”, etc., may indicate only a, only b, only c, (e.g., both a and b), (e.g., both a and c), (e.g., both b and c), all of a, b, and c, or variations thereof.

[0035] For ease of description, the dimensions and thickness of the construction are optionally shown in the accompanying drawings, and this disclosure is not limited thereto.

[0036] In the accompanying drawings, the thickness of layers, films, panels, regions, etc., is exaggerated for clarity. The thickness of some layers and regions is also exaggerated in the accompanying drawings for better understanding and ease of description. It should be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on said other element, or an intervening element may be present.

[0037] In some embodiments, unless explicitly stated otherwise, the word “comprising” and its variations shall be construed as implying the inclusion of the stated elements but excluding any other elements.

[0038] Here, exemplary embodiments are described with reference to cross-sectional views, which are schematic diagrams of idealized embodiments. Thus, variations in the shapes shown should be expected depending on, for example, manufacturing techniques and / or tolerances. Therefore, the embodiments described in this disclosure should not be construed as limited to the specific shapes of the regions shown in this disclosure, but should include variations in shape caused, for example, by manufacturing processes. For example, regions shown or described as flat may generally have rough and / or non-linear characteristics. Furthermore, corners shown as sharp may be rounded. Therefore, the regions shown in the figures are schematic in nature, and the shapes are not intended to depict the precise shapes of the regions, nor are they intended to limit the scope of the claims.

[0039] This disclosure may be implemented in many different forms and should not be construed as limited to the embodiments described herein. The embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art. The same reference numerals denote the same elements.

[0040] It will be understood that if an element is referred to as "on" another element (e.g., when an element is referred to as "on" another element), then the element may be directly on top of the other element, or there may be other elements between the element and the other element. Conversely, if an element is referred to as "directly on" another element (e.g., when an element is referred to as "directly on" another element), then there are no intervening elements between them.

[0041] In this disclosure, terms such as "first," "second," "third," etc., may be used to describe one or more suitable elements, components, regions, layers, and / or areas, and these elements, components, regions, layers, and / or areas should not be limited by these terms. These terms are used only to distinguish one element, component, region, layer, or area from another element, component, region, layer, or area. Therefore, without departing from the teachings of this disclosure, a first element, component, region, layer, or area described herein may be referred to as a second element, component, region, layer, or area.

[0042] The terminology used in this disclosure is not intended to describe specific embodiments only and is not intended to limit the disclosure. Unless the content (e.g., quantity) expressly specifies otherwise, the singular form used herein is intended to include the plural form (including "at least one"). Furthermore, when describing embodiments of this disclosure, the use of "may" refers to "one or more embodiments of this disclosure." "At least one" should not be construed as limited to the singular. The term "and / or" as used herein includes any and all combinations of one or more of the listed items. The term "comprising" and / or variations thereof used in the detailed description indicate the presence of a specified feature, region, integral, step, operation, element, and / or component, and do not exclude the presence or addition of one or more other features, regions, integrals, steps, operations, elements, and / or groups thereof.

[0043] Spatial relative terms such as “below,” “under,” “lower,” “above,” “above,” and “upper” are used to facilitate the description of the relationship between one element or feature and another. It will be understood that, in addition to the orientations shown in the figures, spatial relative terms are intended to include different orientations of the device in use or operation. For example, if the device in the figures is flipped (e.g., when the device in the figures is flipped), an element described as “below” or “under” another element or feature will be oriented as “above” said other element or feature. Thus, the example term “below” can encompass (e.g., simultaneously) both above and below orientations. The device can be positioned in different orientations (rotated 90 degrees or rotated in other directions), and the spatial relative terms used in this disclosure can be interpreted accordingly.

[0044] "Group" refers to the group of elements in the periodic table according to the grouping system of the International Union of Pure and Applied Chemistry ("IUPAC") from Group 1 to Group 18.

[0045] As used herein, the terms “substantially” and similar terms are used as approximations rather than terms of degree, and are intended to account for inherent biases in measured or calculated values ​​that would be recognized by one of ordinary skill in the art. Furthermore, taking into account the measurements discussed and the errors associated with the measurement of a particular quantity (e.g., limitations of the measurement system), the terms “about” and similar terms, when used herein in conjunction with numerical values ​​or ranges of values, include the stated value and values ​​within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art. For example, “about” may refer to within one or more standard deviations, or within ±30%, ±20%, ±10%, ±5% of the stated value.

[0046] Furthermore, any numerical range described herein is intended to include all subranges containing the same numerical precision within the described range. For example, the range “1.0 to 10.0” is intended to include all subranges between the described minimum value of 1.0 and the described maximum value of 10.0 (and including both the described minimum value of 1.0 and the described maximum value of 10.0), i.e., having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as 2.4 to 7.6. Any maximum numerical limit described herein is intended to include all lower numerical limits contained therein, and any minimum numerical limit described in this specification is intended to include all higher numerical limits contained therein. Therefore, the applicant reserves the right to amend this specification and claims to expressly describe any subranges contained within the range expressly described herein.

[0047] Although specific embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are not currently conceived or foreseen by the applicant or those skilled in the art will come to mind. Therefore, the appended claims, as filed and as amended, are intended to cover all such alternatives, modifications, variations, improvements, and substantial equivalents.

[0048] The electrode assembly and the rechargeable battery including the electrode assembly, according to the example embodiments, will be described in more detail below.

[0049] Figure 1 It is a top plan view (e.g., a plan view) of the electrodes according to the embodiment, and Figure 2 It is along Figure 1 The sectional view taken from line II-II'.

[0050] like Figure 1 and Figure 2As shown, the electrode according to the embodiment may include a substrate 70, a functional layer 71 formed on the substrate 70, and an active material layer 72 formed on the functional layer 71.

[0051] If the electrode is a positive electrode (e.g., when the electrode is a positive electrode), the substrate 70 may include aluminum (Al).

[0052] Functional layer 71 may include materials comprising compounds represented by chemical formula 1, compounds represented by chemical formula 2, or combinations thereof:

[0053] Chemical Formula 1

[0054] Li a1 M 1 x1 Fe 1-x1 PO4

[0055] In chemical formula 1, 0.90 ≤ a1 ≤ 1.5, 0 ≤ x1 ≤ 0.4, M 1 It is Mg, Co, Ni or a combination thereof.

[0056] Chemical formula 2

[0057] Li a2 Mn x2 Fe 1-x2 PO4

[0058] In chemical formula 2, 0.90≤a2≤1.5, 0.1≤x2≤1.

[0059] The compound represented by Formula 1 can be a lithium iron phosphate compound. In Formula 1, the mole fraction of lithium can be appropriately adjusted between about 0.9 and 1.5, for example, 0.90 ≤ a1 ≤ 1.2, or 0.95 ≤ a1 ≤ 1.1. In Formula 1, Mn may also be present in addition to Fe, and the mole fraction of Mn can be 0 ≤ x1 ≤ 0.7, 0 ≤ x1 ≤ 0.5, 0 ≤ x1 ≤ 0.3, 0 ≤ x1 ≤ 0.1, or 0 ≤ x1 ≤ 0.05.

[0060] The compound represented by Formula 2 can be lithium manganese phosphate. In Formula 2, as in Formula 1, the mole fraction of lithium can be 0.90 ≤ a² ≤ 1.2 or 0.95 ≤ a² ≤ 1.1. In Formula 2, the mole fraction of manganese can be 0.2 ≤ x² ≤ 0.9, 0.3 ≤ x² ≤ 0.9, or 0.4 ≤ x² ≤ 0.8, and when 0.5 ≤ x² ≤ 0.9, the lithium-ion conductivity is high.

[0061] For example, functional layer 71 is a lithium transition metal phosphate and may include LiFePO4, LiMn 0.5 Fe 0.5 PO4, LiMnPO4, etc.

[0062] The functional layer 71 includes the aforementioned material and may also include an adhesive and / or a conductive material (such as an electronic conductor). Here, the content (e.g., amount) of the material relative to the total weight of the functional layer 71 may be from about 80 wt% to about 95 wt%. The content (e.g., amount) of the adhesive relative to the total weight of the functional layer 71 may be from about 1 wt% to about 10 wt%, and the content (e.g., amount) of the conductive material relative to the total weight of the functional layer 71 may be from about 0.1 wt% to about 10 wt%.

[0063] The adhesive can adhere material particles within the functional layer to each other and to the substrate, and the adhesive can include non-water-soluble adhesives, water-soluble adhesives, or combinations thereof.

[0064] The non-water-soluble adhesive may be polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers including ethylene oxide, ethylene propylene copolymers, polystyrene, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamide-imide, polyimide, or combinations thereof.

[0065] Water-soluble adhesives include rubber-based adhesives or polymeric resin adhesives. Rubber-based adhesives may be selected from styrene-butadiene rubber (SBR), acrylated styrene-butadiene rubber, acrylonitrile-butadiene rubber (ABR), acryloyl rubber, butyl rubber, fluororubber, and one or more combinations thereof. Polymeric resin adhesives may be selected from polyethylene oxide, polyvinylpyrrolidone, polyepoxychloropropane, polyphosphazene, polyacrylonitrile, ethylene-propylene-diene copolymer, polyvinylpyridine, chlorosulfonated polyethylene, latex, polyester resin, acryloyl resin, phenolic resin, epoxy resin, polyvinyl alcohol, and combinations thereof.

[0066] When a water-soluble binder is used as a binder, it may also include a cellulose compound that imparts viscosity. This cellulose compound can be used by mixing one or more types (species) of carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, or their alkali metal salts. Na, K, or Li can be used as the alkali metal.

[0067] Conductive materials are used to impart conductivity, and conductive materials may include carbon-based materials, metallic materials, conductive polymers, or mixtures thereof.

[0068] The conductive material included in functional layer 71 can be any electronically conductive material that does not cause chemical changes in the battery including the conductive material. For example, materials such as: conductive materials including natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, superconducting acetylene black (denka black), carbon materials (such as carbon fibers), copper, nickel, aluminum, silver, etc., and including metallic materials (such as metal powders or metal fiber types (or similar)); conductive polymers (such as polyphenylene derivatives); or mixtures thereof. Active material layer 72 includes a positive electrode active material, and the positive electrode active material can be a compound capable of reversibly inserting and deintercalating lithium ions (lithiation intercalation compound). The positive electrode active material is a compound expressed or represented by at least one of the following example formulas. That is, the example formulas may include:

[0069] Li a A 1-b X b D2(0.90≤a≤1.8, 0≤b≤0.5);

[0070] Li a A 1-b X b O 2-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05);

[0071] Li a E 1-b X b O 2-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05);

[0072] Li a E 2-b X b O 4-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05);

[0073] Li a Ni 1-b-c Co b X c D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α≤2);

[0074] Li a Ni 1-b-c Co b X c O 2-α T α(0.90≤a≤1.8,0≤b≤0.5,0≤c≤0.05,0<α<2);

[0075] Li a Ni 1-b-c Co b X c O 2-α T2(0.90≤a≤1.8,0≤b≤0.5,0≤c≤0.05,0<α<2);

[0076] Li a Ni 1-b-c Mr b X c D α (0.90≤a≤1.8,0≤b≤0.5,0≤c≤0.05,0<α≤2);

[0077] Li a Ni 1-b-c Mr b X c O 2-α T α (0.90≤a≤1.8,0≤b≤0.5,0≤c≤0.05,0<α<2);

[0078] Li a Ni 1-b-c Mr b X c O 2-α T2(0.90≤a≤1.8,0≤b≤0.5,0≤c≤0.05,0<α<2);

[0079] Li a Ni b HAVE BEEN c G d O2(0.90≤a≤1.8,0≤b≤0.9,0≤c≤0.5,0.001≤d≤0.1);

[0080] Li a Ni b Co c Mr d G e O2(0.90≤a≤1.8,0≤b≤0.9,0≤c≤0.5,0≤d≤0.5,0.001≤e≤0.1);

[0081] Li a NiG b O2(0.90≤a≤1.8,0.001≤b≤0.1);

[0082] Li a CoGb O2(0.90≤a≤1.8, 0.001≤b≤0.1);

[0083] Li a Mn 1-b G b O2(0.90≤a≤1.8, 0.001≤b≤0.1);

[0084] Li a Mn2G b O4(0.90≤a≤1.8, 0.001≤b≤0.1);

[0085] Li a Mn 1-g G g PO4(0.90≤a≤1.8, 0≤g≤0.5);

[0086] QO2; QS2; LiQS2;

[0087] V₂O₅; LiV₂O₅;

[0088] LiZO2;

[0089] LiNiVO4;

[0090] Li (3-f) J2(PO4)3(0≤f≤2);

[0091] Li (3-f) Fe2(PO4)3 (0≤f≤2); and / or

[0092] Li a FePO4 (0.90≤a≤1.8).

[0093] In the above formula, A is selected from the group consisting of Ni, Co, Mn and their combinations; X is selected from the group consisting of Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements and their combinations; D is selected from the group consisting of O, F, S, P and their combinations; E is selected from the group consisting of Co, Mn and their combinations; T is selected from the group consisting of F, S, P and their combinations; G is selected from the group consisting of Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V and their combinations; Q is selected from the group consisting of Ti, Mo, Mn and their combinations; Z is selected from the group consisting of Cr, V, Fe, Sc, Y and their combinations; and J is selected from the group consisting of V, Cr, Mn, Co, Ni, Cu and their combinations.

[0094] Of course, a coating layer can be applied to the surface of the compound, or a mixture of the compound and compounds included in the coating layer can be used. The coating layer may include at least one compound of the coating element selected from oxides, hydroxides, hydroxyoxides, oxycarbonates, and hydroxycarbonates of the coating element. The compound used for the coating layer may be amorphous or crystalline. The coating element included in the coating layer may include Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or mixtures thereof. The coating layer formation process may use any coating method that utilizes the elements in the compound without adversely affecting the physical properties of the positive electrode active material, such as spraying, dipping, etc.

[0095] Examples of positive electrode active materials may include positive electrode active materials represented by the chemical formula A1:

[0096] Chemical formula A1

[0097] Li a11 Ni x11 M 11 y11 M 12 1-x11-y12 O2

[0098] In chemical formula A1, 0.9 ≤ a11 ≤ 1.8, 0.3 ≤ x11 ≤ 1, 0 ≤ y11 ≤ 0.7, M 11 and M 12 Each is independently selected from Al, B, Ce, Co, Cr, F, Mg, Mn, Mo, Nb, P, S, Si, Sr, Ti, V, W, Zr, and combinations thereof.

[0099] In chemical formula A1, 0.4≤x11≤1 and 0≤y11≤0.6 can be 0.5≤x11≤1 and 0≤y11≤0.5, or 0.6≤x11≤1 and 0≤y11≤0.4, or 0.7≤x11≤1 and 0≤y11≤0.3, or 0.8≤x11≤1 and 0≤y11≤0.2, or 0.9≤x11≤1 and 0≤y11≤0.1.

[0100] The positive electrode active material may include, for example, a lithium nickel cobalt composite oxide represented by the chemical formula A2.

[0101] Chemical formula A2

[0102] Li a12 Ni x12 Co y12 M 13 1-x12-y12 O2

[0103] In chemical formula A2, 0.9 ≤ a12 ≤ 1.8, 0.3 ≤ x12 ≤ 0.99, 0.01 ≤ y12 ≤ 0.7, and M 13 Selected from Al, B, Ce, Cr, F, Mg, Mn, Mo, Nb, P, S, Si, Sr, Ti, V, W, Zr and combinations thereof.

[0104] In chemical formula A2, 0.3≤x12≤0.99 and 0.01≤y12≤0.7, or 0.4≤x12≤0.99 and 0.01≤y12≤0.6, or 0.5≤x12≤0.99 and 0.01≤y12≤0.5, or 0.6≤x12≤0.99 and 0.01≤y12≤0.4, or 0.7≤x12≤0.99 and 0.01≤y12≤0.3, or 0.8≤x12≤0.99 and 0.01≤y12≤0.2, or 0.9≤x12≤0.99 and 0.01≤y12≤0.1.

[0105] The positive electrode active material may include lithium nickel cobalt composite oxide represented by the chemical formula A3 as a specific example.

[0106] Chemical formula A3

[0107] Li a13 Ni x13 Co y13 M 14 z13 M 15 1-x13-y13-z13 O2

[0108] In chemical formula A3, 0.9 ≤ a13 ≤ 1.8, 0.3 ≤ x13 ≤ 0.98, 0.01 ≤ y13 ≤ 0.69, 0.01 ≤ z13 ≤ 0.69, M 14 Selected from Al, Mn and their combinations, and M 15 Selected from B, Ce, Cr, F, Mg, Mo, Nb, P, S, Si, Sr, Ti, V, W, Zr and combinations thereof.

[0109] In chemical formula A3, 0.4 ≤ x13 ≤ 0.98, 0.01 ≤ y13 ≤ 0.59, and 0.01 ≤ z13 ≤ 0.59, or 0.5 ≤ x13 ≤ 0.98, 0.01 ≤ y13 ≤ 0.49, and 0.01 ≤ z13 ≤ 0.49, or 0.6 ≤ x13 ≤ 0.98, 0.01 ≤ y13 ≤ 0.39, and 0.01 ≤ z13 ≤ 0. 0.39, or 0.7≤x13≤0.98, 0.01≤y13≤0.29, and 0.01≤z13≤0.29, or 0.8≤x13≤0.98, 0.01≤y13≤0.19, and 0.01≤z13≤0.19, or 0.9≤x13≤0.98, 0.01≤y13≤0.09, and 0.01≤z13≤0.09.

[0110] The positive electrode active material layer 72 may include a positive electrode active material, and also includes a binder and / or a conductive material. Here, the content (e.g., amount) of the positive electrode active material relative to the total weight of the positive electrode active material layer may be from about 90 wt% to about 98 wt%, for example, from about 90 wt% to about 95 wt%. Based on the total weight of the positive electrode active material layer, the content (e.g., amount) of the binder and the conductive material may be from about 1 wt% to about 5 wt%, respectively.

[0111] The adhesive may be the same as, but is not limited to, the adhesive constituting functional layer 71.

[0112] The binder adheres the positive electrode active material particles to each other and also adheres the positive electrode active material to the functional layer or substrate. The conductive material is used to provide conductivity to the electrode and is the same as the conductive material constituting the functional layer 71.

[0113] In some embodiments, the substrate 70 according to the embodiment has an electrode active region DA and an electrode uncoated region DB, an active material layer 72 is formed in the electrode active region DA, and a separate layer is not formed in the electrode uncoated region DB, and the substrate is exposed.

[0114] At this time, the uncoated area DB of the electrode is used to lead the current to the outside and is limited to the portion protruding from the electrode active area DA, which does not include the substrate portion exposed at the edge around the active material layer (e.g., around the active material layer).

[0115] The functional layer 71 includes a first portion 7 formed in the electrode active region DA and superimposed on the active material layer 72, and a second portion 8 extending into the electrode uncoated region DB.

[0116] The functional layer 71 has a higher resistance value (e.g., electronic resistance or electrical resistance) than the substrate 70 and the active material layer 72, and serves as an insulating layer. Therefore, the second portion 8 is formed only in a portion of the uncoated electrode region DB, such that the portion being soldered to the outside is exposed, and the area of ​​the second portion 8 is formed to be less than approximately 60% of the area of ​​the uncoated electrode region DB.

[0117] At this time, the width L2 of the uncoated area DB can be from about 2 mm to about 7 mm, and the width L1 of the second part 8 can be from about 0.1 mm to about 3 mm.

[0118] The functional layer 71 may be formed to have a wider region than the active material layer 72 and may protrude from the active material layer 72, but may be formed to be smaller than the substrate 70 (for example, the substrate 70 may protrude from the active material layer 72 more than the functional layer 71 protrudes from the active material layer 72), so the boundary line of the functional layer 71 may be located within the boundary line of the substrate 70.

[0119] The above electrodes can be used in stacked (or similar) electrode assemblies, and in the following text, refer to Figure 3 Describes an electrode assembly according to an embodiment.

[0120] Figure 3 This is a schematic exploded perspective view of a stacked (or similar) electrode assembly according to an embodiment, and Figure 4 This is a schematic cross-sectional view of another stacked (or similar) electrode assembly according to an embodiment.

[0121] Reference Figure 3 and Figure 4 According to the embodiment, the electrode assembly 101 is a stacked (or similar) electrode assembly 101 in which the positive electrode 100 and the negative electrode 200 are repeatedly stacked, and the diaphragm 300 is between the positive electrode 100 and the negative electrode 200.

[0122] The membrane 300 is a polymer membrane that allows lithium ions to pass through. It can be made of polyethylene, polypropylene, polyvinylidene fluoride, or two or more of these in multiple layers, and can also be made of mixed multiple layers (such as polyethylene / polypropylene double membranes, polyethylene / polypropylene / polyethylene triple membranes, and polypropylene / polyethylene / polypropylene triple membranes).

[0123] The diaphragm 300 is shown as a sheet resembling positive and negative electrodes, but is not limited thereto, and can form a Z-shaped stacked assembly structure by continuously passing between separate negative and positive electrodes.

[0124] The negative electrode 200 includes an active electrode region and an uncoated electrode region. In the active electrode region, an active material layer 81 is formed on a substrate 80 made of copper (Cu). In the uncoated electrode region, the substrate is exposed because no active material is applied.

[0125] The negative electrode active material included in the active material layer 81 can be a carbon-based negative electrode active material. The carbon-based negative electrode active material can be artificial graphite or a mixture of artificial and natural graphite. When the carbon-based negative electrode active material is a crystalline carbon material or artificial graphite obtained by mixing natural and artificial graphite, the crystalline carbon material has more developed crystallization characteristics than the amorphous carbon-based negative electrode active material, thus further improving the orientation characteristics of the carbon-based negative electrode active material in the electrode plate relative to an external magnetic field. The artificial or natural graphite can be amorphous, sheet-like, flake-like, spherical, fibrous, or a combination thereof, without particular limitation. Furthermore, when using a mixture of artificial and natural graphite, the mixing ratio can be from about 70 wt%:30 wt% to about 95 wt%:5 wt%.

[0126] In some embodiments, the negative electrode active material layer 81 may further include Si-based negative electrode active materials, Sn-based negative electrode active materials, and LiMO. x At least one negative electrode active material among the negative electrode active materials (M = metal). When the negative electrode active material layer further includes a carbon-based negative electrode active material as a first negative electrode active material and the aforementioned negative electrode active material as a second negative electrode active material, the mixing ratio of the first negative electrode active material and the second negative electrode active material can be from about 50 wt%:50 wt% to about 99 wt%:1 wt%.

[0127] LiMO x The negative electrode active material can be lithium vanadium oxide (M = metal).

[0128] Si-based anode active materials can be Si, Si-C complexes, SiO2, etc. x(0 < x < 2) or an Si-Q alloy (Q is an element selected from the group consisting of alkali metals, alkaline earth metals, Group 13 elements, Group 14 elements, Group 15 elements, Group 16 elements, transition metals, rare earth elements, and combinations thereof), and the Sn-based negative electrode active material may include Sn, SnO2, and Sn-R alloys (R is an element selected from the group consisting of alkali metals, alkaline earth metals, Group 13 elements, Group 14 elements, Group 15 elements, Group 16 elements, transition metals, and rare earth elements, and does not include Sn), and at least one of them may be mixed with SiO2. The element Q and the element R may be at least one element selected from the group consisting of Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Pb, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Tl, Ge, P, As, Sb, Bi, S, Se, Te, Po, and one or more combinations thereof.

[0129] Based on the total weight of the negative electrode active material layer, the content (e.g., amount) of the negative electrode active material in the negative electrode active material layer 81 may be about 95 wt% to about 99 wt%.

[0130] The negative electrode active material layer includes a binder and may also optionally include a conductive material. Based on the total weight of the negative electrode active material layer, the content (e.g., amount) of the binder in the negative electrode active material layer may be about 1 wt% to about 5 wt%. In some embodiments, when a conductive material is also included, the negative electrode active material may be used in an amount of about 90 wt% to about 98 wt%, the binder may be used in an amount of about 1 wt% to about 5 wt%, and the conductive material may be used in an amount of about 1 wt% to about 5 wt%.

[0131] The binder is used to adhere the negative electrode active material particles to each other and is also used to adhere the negative electrode active material to the negative electrode substrate. As the binder, a non-aqueous binder, an aqueous binder, or a combination thereof may be used.

[0132] Examples of the non-aqueous binder may include polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers including ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamide-imide, polyimide, and / or combinations thereof.

[0133] Examples of waterborne adhesives may include styrene-butadiene rubber (SBR), acrylated styrene-butadiene rubber, acrylonitrile-butadiene rubber, acryloyl rubber, butyl rubber, ethylene-propylene copolymer, polyepoxychloropropane, polyphosphazene, polyvinylpyridine, chlorosulfonated polyethylene, latex, polyester resin, acryloyl resin, phenolic resin, epoxy resin, polyvinyl alcohol, acrylate resin and / or combinations thereof.

[0134] When an aqueous binder is used as a negative electrode binder, it may also contain a cellulose-based compound as a thickener capable of imparting viscosity. As a cellulose-based compound, carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and their alkali metal salts may be used in combination. As an alkali metal, Na, K, or Li may be used. Based on approximately 100 parts by weight of the negative electrode active material, the content (e.g., amount) of the thickener may be from approximately 0.1 parts by weight to approximately 3 parts by weight.

[0135] Conductive materials are used to impart conductivity to electrodes, and any electronically conductive material that does not cause chemical changes in the battery can be used. Examples of conductive materials may include carbon-based materials (such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, and / or carbon fibers); metal powders (such as copper, nickel, aluminum, and / or silver); metallic materials (such as metal fibers); conductive polymers (such as polyphenylene derivatives); and / or conductive materials comprising mixtures thereof.

[0136] The BET specific surface area of ​​the negative electrode active material layer can be less than approximately 3.0 m². 2 / g, and can be in about 0.6m 2 / g to approximately 1.2m 2 Within the range of / g. When the BET specific surface area of ​​the negative electrode active material layer is less than approximately 3.0 m². 2 When the concentration is / g, the electrochemical life characteristics of the battery can be improved.

[0137] By charging / discharging a lithium rechargeable battery including a negative electrode, the negative electrode, obtained by breaking the battery in a fully discharged state, is cut into a set or predetermined size, and then the cut negative electrode is placed in a BET sample holder to measure BET.

[0138] The negative electrode can have approximately 6 mg / cm². 2 Approximately 65 mg / cm 2 The profile load level (L / L).

[0139] The positive electrode 100 includes a coated region and an uncoated region. In the coated region, an active material is applied to a current collector on a metal substrate made of aluminum (Al). In the uncoated region, the metal substrate is exposed because no active material is applied. The positive electrode may include... Figure 1 and Figure 2 The electrodes shown.

[0140] The negative electrode 200 can be formed to be larger than the positive electrode 100. For example, the distance between the boundary of the negative electrode 200 and the boundary of the positive electrode 100 can be about 0.5 mm to about 0.3 mm. When the active material layer and the electrode substrate of different polarities come into contact, a short circuit may occur. However, in one embodiment of this disclosure, by forming a functional layer 71 with a resistance value that is larger than that of the electrode substrate and the active material layer, an insulation effect between them can be achieved.

[0141] Multiple uncoated areas of the positive electrode 100 and the negative electrode 200 can be electrically connected to external terminals by electrical connection with the same polarity. The uncoated areas of the positive electrode 100 and the negative electrode 200 may protrude in substantially the same direction, but they are not limited thereto, and they may protrude in opposite directions and be spaced apart from each other.

[0142] The diaphragm 300 can be formed to be larger than the negative electrode 200 and the positive electrode 100, and to bulge outward from the negative electrode 200 and the positive electrode 100.

[0143] Figure 5 It shows along Figure 1 The cross-sectional view of the positive electrode according to the embodiment is taken from line II-II'.

[0144] Reference Figure 4 and Figure 5 In the electrode assembly 101, multiple positive electrodes, diaphragms and negative electrodes are repeatedly stacked. The first positive electrode 100A, located on the outermost side of the electrode assembly 101 (e.g., on the top side or bottom side, or on the outermost top side or the outermost bottom side), has an active material layer 72 formed only on one side of the substrate, and the second positive electrode 100B, located opposite the center of the electrode assembly 101, has active material layers formed on both sides of the substrate (e.g., opposite sides).

[0145] For the first positive electrode 100A, the active material layer 72 is formed on one surface of the substrate 70 facing the negative electrode, that is, on one surface relatively adjacent to the center of the electrode assembly.

[0146] The surface of the substrate 70 is positioned toward (e.g., facing) the negative electrode 200 and the center of the stacked (or similar) electrode assembly 101 along the stacking direction (e.g., in the stacking direction or thickness direction) of the stacked (or similar) electrode assembly 101.

[0147] Furthermore, the active material layer is not formed on the other surface of the substrate 70, that is, it is not formed on the other surface that is relatively far from the center.

[0148] The aforementioned functional layer 71 may be located between the substrate 70 and the active material layer 72, and the ceramic layer 73 in contact with the substrate 70 may be formed on the other surface of the substrate 70.

[0149] Similar to the functional layer 71, the ceramic layer 73 includes a portion that protrudes toward an uncoated area of ​​the electrode (e.g., an uncoated area of ​​the substrate 70). The ceramic layer 73 may protrude to the same width as the functional layer 71, but depending on the process, there may be an error of approximately ±2 mm from one end S of the functional layer 71. The ceramic layer 73 may be formed to have a thickness of 5 μm to 20 μm.

[0150] The ceramic layer 73 is an insulating material that can prevent or reduce short circuits in the battery due to external impacts.

[0151] The ceramic layer 73 may include ceramic and an adhesive, and in the total weight of the ceramic layer, it includes ceramic in about 80 wt% to about 97 wt% and adhesive in about 3 wt% to about 20 wt%.

[0152] Ceramics may include endothermic ceramics (such as boehmite and boehmite); common ceramics (such as alumina (Al2O3, etc.), silicon dioxide (SiO2), magnesium oxide (MgO), titanium oxide (TiO2), hafnium oxide (HfO2), tin oxide (SnO), cerium oxide (IV) (CeO2), nickel oxide (NiO), zinc oxide (ZnO), calcium oxide (CaO), zirconium oxide (ZrO2), yttrium oxide (Y2O3), silicon carbide (SiC), etc.); or combinations thereof.

[0153] Ordinary ceramics are insulating materials that only have insulating properties, while heat-absorbing ceramics are heat-absorbing materials that have both insulating and heat-absorbing properties (for example, simultaneously).

[0154] Adhesives may include non-water-soluble adhesives, water-soluble adhesives, or combinations thereof.

[0155] The adhesive bonds the materials within the ceramic layer well to each other and ensures that the ceramic layer adheres well to the substrate.

[0156] As a non-water-soluble adhesive, it can be polyvinyl chloride, carboxylated polyvinyl chloride, polyvinylidene fluoride, polymers including ethylene oxide, ethylene propylene copolymers, polystyrene, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamide-imide, polyimide, or combinations thereof.

[0157] Water-soluble adhesives can be rubber-based adhesives or polymer resin adhesives. Rubber-based adhesives can be selected from styrene-butadiene rubber (SBR), acrylated styrene-butadiene rubber, acrylonitrile-butadiene rubber, acrylic rubber, butyl rubber, fluororubber, and combinations thereof. Polymer resin adhesives can be selected from polyethylene oxide, polyvinylpyrrolidone, polyepoxychloropropane, polyphosphazene, polyacrylonitrile, ethylene-propylene-diene copolymer, polyvinylpyridine, chlorosulfonated polyethylene, latex, polyester resin, acrylic resin, phenolic resin, epoxy resin, polyvinyl alcohol, and combinations thereof.

[0158] When a water-soluble binder is used as the binder, it may also include a cellulose compound that imparts viscosity. As a cellulose compound, one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and their alkali metal salts may be mixed and used. As an alkali metal, Na, K, or Li may be used.

[0159] The electrode assembly 101 can be housed together with the electrolyte in a prismatic housing in the shape of a bag or can, and can be used as a rechargeable battery.

[0160] Electrolytes include non-aqueous organic solvents and lithium salts. The non-aqueous organic solvents serve as a medium through which ions participating in the electrochemical reactions of the battery can move.

[0161] Lithium salts are dissolved in organic solvents and used as a source of lithium ions in batteries, enabling basic lithium-ion secondary battery operation, and are materials that facilitate the movement of lithium ions between the positive and negative electrodes. Representative examples of such lithium salts include LiPF6, LiBF4, LiSbF6, LiAsF6, LiN(SO2C2F5)2, Li(CF3SO2)2N, LiN(SO3C2F5)2, LiC4F9SO3, LiClO4, LiAlO2, LiAlCl4, and LiN(C x F 2x+1 SO2), C y F 2y+1 One or more of the following groups: SO2 (where x and y are natural numbers, such as integers from 1 to 20), LiCl, LiI, and LiB(C2O4)2 (lithium dioxolaneborate (lithium di(oxolane)borate): LiBOB).

[0162] The lithium salt concentration should be used in the range of about 0.1 M to about 2.0 M. When the lithium salt concentration is within this range, the electrolyte has appropriate or suitable conductivity and viscosity, so it can exhibit excellent or suitable electrolyte performance, and lithium ions can move efficiently.

[0163] In this disclosure, terms such as "excluding one or any 'component'", "excluding one or any 'component'", and "containing no 'component'" mean that the 'component' has not been added, selected, or used as a component in the composition or compound, but may still include less than a suitable amount of the 'component' due to other impurities and / or external factors.

[0164] The battery management system (BMS) device and / or any other related device or component according to embodiments of the invention described herein can be implemented using any suitable hardware, firmware (e.g., application-specific integrated circuit), software, or a combination of software, firmware, and hardware. For example, various components of the device can be formed on an integrated circuit (IC) chip or on separate IC chips. Furthermore, various components of the device can be implemented on a flexible printed circuit film, a tape-on-a-package (TCP), a printed circuit board (PCB), or formed on a substrate. Additionally, various components of the device can be processes or threads executing computer program instructions and interacting with other system components for performing the various functions described herein, running on one or more processors in one or more computing devices. The computer program instructions are stored in memory, which can be implemented in a computing device using standard memory devices, such as random access memory (RAM). The computer program instructions can also be stored in other non-transitory computer-readable media, such as CD-ROMs, flash drives, etc. Furthermore, those skilled in the art will recognize that, without departing from the scope of this disclosure, the functionality of various computing devices can be combined or integrated into a single computing device, or the functionality of a particular computing device can be distributed across one or more other computing devices.

[0165] While this disclosure has been described in conjunction with embodiments now considered practical, it will be understood that the disclosure is not limited to the disclosed embodiments, but rather is intended to cover one or more suitable modifications and equivalent arrangements included within the spirit and scope of the appended claims.

[0166] Description of reference numerals in the attached figures

[0167] 70: Substrate; 71: Functional layer

[0168] 72: Active material layer; 100: Positive electrode

[0169] 101: Electrode assembly; 200: Negative electrode

[0170] 300: Diaphragm.

Claims

1. An electrode assembly, comprising: A stacked electrode assembly in which positive electrodes, separators, and negative electrodes are alternately stacked, wherein the positive electrode is located at the outermost side of the stacked electrode assembly, the positive electrode comprises a substrate having an electrode uncoated region and an electrode active region, an active material layer on one surface of the substrate in the electrode active region, and a ceramic layer on an opposite surface of the substrate in the electrode active region, and The one surface of the substrate faces the negative electrode and the center of the stacked type electrode assembly in a stacking direction of the stacked type electrode assembly.

2. The electrode assembly according to claim 1, further comprising: The functional layer is between the substrate and the active material layer.

3. The electrode assembly according to claim 2, wherein: The functional layer includes a first portion overlapping the electrode active area and a second portion extending from the first portion to the electrode uncoated area.

4. The electrode assembly according to claim 3, wherein: The ceramic layer and the functional layer have the same planar shape.

5. The electrode assembly according to claim 3, wherein: The area of ​​the second portion is less than 60% of the uncoated area of ​​the electrode.

6. The electrode assembly according to claim 5, wherein: The second portion has a width of 0.1 mm to 3 mm.

7. The electrode assembly according to claim 2, wherein: The functional layer has a resistance value greater than a resistance value of each of the substrate and the active material layer.

8. The electrode assembly according to claim 2, wherein: The boundary of the functional layer is located within the boundary of the substrate.

9. The electrode assembly according to claim 2, wherein: The functional layer includes a material including a compound represented by Chemical Formula 1, a compound represented by Chemical Formula 2, or a combination thereof: Chemical formula 1 Li a1 M 1 x1 Fe 1-x1 PO4 In Chemical Formula 1, 0.90≤a1≤1.5, 0≤x1≤0.4, and M 1 is Mg, Co, Ni or a combination thereof, chemical formula 2 Li a2 Mn x2 Fe 1-x2 PO4 In chemical formula 2, 0.90≤a2≤1.5, 0.1≤x2≤1.

10. The electrode assembly according to claim 1, wherein: The width of the uncoated area of ​​the electrode is 2 mm to 7 mm.

11. The electrode assembly according to claim 1, wherein: The electrode uncoated area protrudes from one side of the electrode active area.

12. The electrode assembly according to claim 11, wherein: A distance between a boundary of the positive electrode and a boundary of the negative electrode is 0.5 mm to 3.0 mm.

13. A rechargeable battery, comprising: The electrode assembly and electrolyte according to claim 1.

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