Electrode and rechargeable battery including the same

Abstract

An electrode for a rechargeable battery and a rechargeable battery including the same are provided. An electrode for a rechargeable battery according to an example embodiment includes a substrate, an active material layer formed on the substrate, a hole formed in the active material layer, and first and second grooves formed on both sides of the hole and spaced apart from the hole.

Description

Technical Field

[0001] This disclosure relates to an electrode and a rechargeable battery including the electrode. Background Technology

[0002] With the development of portable device technology, the demand for rechargeable batteries as an energy source is growing. Unlike primary batteries, rechargeable batteries can be repeatedly charged and discharged.

[0003] Electrode assemblies for rechargeable batteries can be manufactured by the following steps: stacking a positive electrode, a separator, and a negative electrode, and then winding the positive electrode, separator, and negative electrode to form a cylindrical or core-shaped electrode assembly; or dividing the positive electrode, separator, and negative electrode into sheets and then laminating them to form a laminated electrode assembly.

[0004] In rechargeable batteries, electrode assemblies are inserted into a housing, and then an electrolyte is injected. The amount of electrolyte impregnation can vary depending on the state of the edges and center of the electrode assembly or active material layer.

[0005] An uneven electrolyte can cause lithium (Li) precipitation, which can shorten battery life and make fast charging challenging. Summary of the Invention

[0006] Examples of this disclosure provide an electrode capable of reducing electrolyte non-uniformity at the edges and center of the electrode, and a rechargeable battery including the electrode.

[0007] An electrode for a rechargeable battery according to an example embodiment includes a substrate, an active material layer formed on the substrate, a pore formed in the active material layer, and a first groove and a second groove formed on both sides of the pore and spaced apart from the pore.

[0008] The sum of the lengths of the first groove and the second groove can be in the range of about 10% to about 80% of the length of the active material layer in the first direction.

[0009] The spacing between the first groove and the second groove can be in the range of about 10% to about 80% of the length of the active material layer in the first direction.

[0010] The pores can have openings facing the surface of the active material layer, can be formed in multiples, and can be arranged at regular intervals.

[0011] The pores can have a shape in which the width narrows as the distance from the surface of the active material layer increases.

[0012] The depths of the first and second grooves can be constant.

[0013] The depth of the first and second grooves can be shallower than the depth of the hole.

[0014] The center of the hole and the horizontal line that bisects the width of the groove can lie on a straight line.

[0015] The first and second grooves may be tilted relative to an imaginary or virtual center line at an angle ranging from about -50 degrees to about 50 degrees, the imaginary or virtual center line passing between the first and second grooves and bisecting the length of the active material layer in the first direction.

[0016] The hole, the first groove, and the second groove may be symmetrical or substantially symmetrical with respect to an imaginary or virtual center line that passes between the first groove and the second groove and bisects the length of the active material layer in the first direction.

[0017] The first and second grooves may include curves.

[0018] The widths of the first and second grooves can be in the range of about 10 μm to about 100 μm, and the spacing between adjacent first grooves and the spacing between adjacent second grooves can be in the range of about 70 μm to about 300 μm.

[0019] The diameter of the hole can range from about 10 μm to about 100 μm.

[0020] A rechargeable battery according to another example embodiment includes: an electrode assembly including a positive electrode, a negative electrode stacked with the positive electrode, and a separator located between the positive and negative electrodes; a housing housing the electrode assembly; an electrolyte injected into the housing; and a cap assembly sealing the housing. At least one of the positive and negative electrodes includes: an active material layer having a substrate; a first groove and a second groove formed on the substrate and spaced apart from each other in the direction of electrolyte injection; and a hole located between the first groove and the second groove.

[0021] The sum of the lengths of the first groove and the second groove can be in the range of about 10% to about 80% of the length of the active material layer in the direction along which the electrolyte is injected.

[0022] The spacing between the first and second grooves can be in the range of about 10% to about 80% of the length of the active material layer in the direction along which the electrolyte is injected.

[0023] Multiple holes can be formed and can be set at a given interval.

[0024] The first and second grooves may be tilted relative to an imaginary or virtual centerline at an angle ranging from about -50 degrees to about 50 degrees, the imaginary or virtual centerline passing between the first and second grooves and bisecting the length of the active material layer in the direction along which the electrolyte is injected.

[0025] The hole, the first groove, and the second groove are symmetrical or substantially symmetrical with respect to an imaginary or virtual center line that passes between the first groove and the second groove and bisects the length of the active material layer in the direction along which the electrolyte is injected.

[0026] The first and second grooves may include curves.

[0027] As described in this disclosure, when grooves and pores are formed, the electrolyte moves and remains at both the edges and the center for a short period of time, resulting in uniform electrolyte impregnation at both the edges and the center. Therefore, by reducing or preventing lithium deposition due to uneven electrolyte distribution, the lifespan of the rechargeable battery can be increased. Attached Figure Description

[0028] The accompanying drawings illustrate exemplary embodiments of the present disclosure and, together with the detailed description of the present disclosure, further describe aspects and features of the present disclosure; therefore, the present disclosure should not be construed as limited to the drawings.

[0029] Figure 1 This is a top plan view of electrodes included in a rechargeable battery according to an example embodiment.

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

[0031] Figures 3 to 6 This is a top plan view of the electrodes according to another example embodiment.

[0032] Figure 7 This is a top plan view of electrodes included in a rechargeable battery according to another example embodiment.

[0033] Figure 8 This is a schematic perspective view of a rechargeable battery according to an example embodiment.

[0034] Figure 9 yes Figure 8 The image shows a longitudinal cross-sectional view of the rechargeable battery.

[0035] Figure 10 yes Figure 8 The image shows a cross-sectional view of the rechargeable battery. Detailed Implementation

[0036] In the following, exemplary embodiments of this disclosure are described in detail with reference to the accompanying drawings. The terms or words used in this specification and claims are not to be construed as having their ordinary or dictionary meaning, but rather are to be interpreted as having meanings and concepts consistent with the technical spirit of this disclosure, based on the principle that the inventor can define the concepts of terms to describe his / her disclosure in a desired manner. The exemplary embodiments described in this specification and the constructions shown in the accompanying drawings are merely some exemplary embodiments of this disclosure and do not represent all technical aspects and features of this disclosure. Therefore, it should be understood that various equivalents and modifications may replace or modify the exemplary embodiments described herein at the time of filing this application.

[0037] It should also be understood that when the terms “comprising” and variations thereof and / or “including” and variations thereof are used in this specification, it indicates the presence of the stated features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, quantities, steps, operations, elements, components and / or groups thereof.

[0038] In the accompanying drawings, the dimensions of various elements, layers, etc., may be exaggerated for clarity. The same reference numerals in different embodiments may denote the same elements.

[0039] Although terms such as "first" and "second" are used to describe various constructions, components are not limited by these terms. These terms are only used to distinguish one component from another, and unless otherwise stated, the first component can also be the second component.

[0040] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0041] For ease of description, spatial relative terms such as "below," "under," "lower," "above," and "upper" are used herein to describe the relationship between an element or feature as shown in the accompanying drawings and one or more other elements or features. It should be understood that, in addition to the orientation shown in the figures, these spatial relative terms are also intended to cover different orientations of the device during use or operation. For example, when the device in the figures is flipped, an element described as "below" or "under" other elements or features will subsequently be oriented "above" or "above" other elements or features. Therefore, the term "below" can encompass both above and below orientations.

[0042] It should be understood that when an element or layer is referred to as being “on”, “connected to”, or “bonded to” another element or layer, the element may be “directly on”, “directly connected to”, or “directly bonded to” the other element or layer, or there may be one or more intermediary elements or layers.

[0043] The terminology used in this specification is intended to describe exemplary embodiments of this disclosure and is not intended to limit this disclosure.

[0044] When the terms “about” or “substantially” are used in conjunction with numerical values ​​in this specification, it means that the relevant numerical value includes a tolerance of ±10% around the stated value. When a range is specified, the range includes all values ​​in increments such as 0.1%.

[0045] Figure 1 This is a top plan view of electrodes included in a rechargeable battery according to an example embodiment. Figure 2 It is along Figure 1 The sectional view taken from line II-II'.

[0046] like Figure 1 and Figure 2 As shown, the electrode 700 according to an example embodiment includes a substrate 70 and an active material layer 71 formed on one surface of the substrate 70. For better understanding and ease of description, the active material layer is shown as formed on one surface, but the active material layer may be formed on both surfaces of the substrate. The electrode 700 is described as an electrode included in a wound-type electrode assembly of a rechargeable battery described below, but is not limited thereto, and may also be used as an electrode in a stacked-type electrode assembly (see reference). Figure 7 ).

[0047] The substrate 70 may include an electrode coated region DA and an electrode uncoated region DB, and an active material layer 71 may be formed in the electrode coated region DA. In the electrode uncoated region DB, since no active material layer 71 is formed, the substrate is exposed, and electrode tabs may be attached to lead current to the outside of the electrode 700.

[0048] like Figure 1 As shown, the uncoated electrode region DB can be located at both ends of the substrate in the length direction X2, but is not limited thereto, and can be formed to extend along the length direction X2 of the substrate, just like the active material layer 71. The length direction X2 can be the winding direction when forming a wound electrode assembly.

[0049] Hole S1 and grooves S2 and S3 can be formed in the active material layer 71.

[0050] The pores S1 can have a generally circular or polygonal planar shape, have openings facing the surface of the active material layer 71, and can be spaced at substantially regular intervals. Because the width of the pores S1 narrows away from the surface of the active material layer 71 and becomes closer to the substrate 70, the pores S1 can have a conical or pyramidal shape.

[0051] The grooves S2 and S3 include a first groove S2 and a second groove S3 located on both sides of the hole S1. The hole S1 and the grooves S2 and S3 can be arranged symmetrically or substantially symmetrically with respect to an imaginary or virtual center line Y that bisects the length of the active material layer 71 in the first direction X1. The first direction of the active material layer 71 can be its width direction.

[0052] The diameter D1 of the pore and the width D2 of the groove S2 or groove S3 can be greater than the particle size (or diameter) of the active material particles, and the depth H1 of the pore S1 and the depth H2 of the grooves S2 and S3 can be greater than the diameter D1 and the width D2. As the depth of the pore S1 increases, the impregnation characteristics are improved. Therefore, the cross-section of the pore S1 and the grooves S2 and S3 in the thickness direction of the active material layer 71 can have a narrow and long shape, and the depth of the grooves S2 and S3 is substantially constant. By forming a deeper pore S1 or groove S2 and S3 in this way, the number of active material particles exposed inside the pore S1 or grooves S2 and S3 increases, thus increasing the contact area between the active material particles and the electrolyte, thereby improving the charging and discharging performance of the rechargeable battery.

[0053] For example, the diameter D1 of hole S1 can be in the range of about 10 μm to about 100 μm, the width D2 of grooves S2 and S3 can be in the range of about 10 μm to about 100 μm, and the depth H1 of hole S1 and the depth H2 of grooves S2 and S3 can be in the range of about 10 μm to about 100 μm. For example, the diameter of polygonal hole S1 is the length of the longest diagonal.

[0054] Multiple holes S1 and grooves S2 / S3 can be formed and arranged at regular intervals along the length direction X2 of the substrate. The interval D3 between adjacent holes or grooves along the length direction X2 can range from approximately 70 μm to approximately 300 μm. For example, the interval D3 between grooves can be greater than the width D2 of the groove.

[0055] The sum of the length L1 of the first groove S2 and the length L2 of the second groove S3 can be in the range of about 10% to about 80% of the width W of the active material layer 71. The width W of the active material layer 71 can be the length along the first direction X1 along which the electrolyte is injected when the electrolyte is injected into the rechargeable battery as described below.

[0056] The depth H1 of hole S1 and the depth H2 of grooves S2 and S3 can be less than about 50% of the thickness T of active material layer 71, and the depth H1 of hole S1 can be greater than the depth H2 of grooves S2 and S3.

[0057] Holes S1 can be formed in multiple ways and can be arranged at a given interval in one direction. Figure 1Two holes S1 are shown between the first groove S2 and the second groove S3, but the number of holes S1 is not limited to this, and more holes S1 can be formed. The spacing L3 between the first groove and the second groove with holes can be in the range of about 10% to about 80% of the width W of the active material layer.

[0058] The lengths L1 of the first groove, L2 of the second groove, and L3 of the spacing between the grooves in the first direction X1 can vary depending on the distance of electrolyte transfer and the width W of the active material layer 71. For example, when the width W is small, the lengths L1 of the first groove S2 and L2 of the second groove S3 can be shorter than the spacing L3 between the grooves S2 and S3. Conversely, as the width W increases, the lengths L1 of the first groove S2 and L2 of the second groove S3 become greater than the spacing L3 between the grooves S2 and S3, thereby allowing the electrolyte to be easily transferred to the central pore.

[0059] In one example embodiment, a hole S1 is disposed between grooves S2 / S3 to be relatively centered on the electrode, and the grooves are formed to extend along a first direction X1 along which the electrolyte is injected, such that the electrolyte moves smoothly (smoothly or smoothly) during injection. Furthermore, the center of the hole S1 and the horizontal line that bisects the width D2 of the grooves S2 and S3 are on the same straight line.

[0060] The orifice is relatively centered, so that a certain amount of electrolyte that has moved through the groove can be retained in the orifice, thereby increasing the amount of electrolyte located at the center of the electrode.

[0061] Depending on the process, the density and thickness of the active material layer may be partially uneven, which may result in variations in the amount and speed of electrolyte injection. However, in the example embodiment, by forming holes S1 and grooves S2 / S3 at regular intervals throughout the active material layer, electrolyte can be injected at a constant speed and amount throughout the active material layer when electrolyte is injected.

[0062] In this way, in the example embodiment, by forming the holes S1 and grooves S2 / S3, the movement and impregnation of the electrolyte can be increased, and the electrolyte can be uniformly or substantially uniformly impregnated throughout the electrode. Therefore, phenomena such as lithium deposition caused by electrolyte inhomogeneity can be reduced.

[0063] The immersion time was measured based on the depth of the hole and is shown in Table 1 below.

[0064] Table 1:

[0065] Comparative Examples 1 and 2, as well as Examples 1, 2, and 3, used the same active material to form an active material layer and fabricated a negative electrode comprising graphite. In Comparative Example 1, no pores were formed; in Comparative Example 2, Examples 1, 2, and 3, the pore diameters were the same, with only the pore depths differing.

[0066] Although Comparative Examples 1 and 2 have a long immersion time of over 160 seconds, the immersion time is reduced from Example 1 to Example 3, with Example 3 reaching 110 seconds (more than 30% faster than Comparative Example 1).

[0067] Figures 3 to 6 This is a top plan view of the electrodes according to another example embodiment.

[0068] Figures 3 to 6 Electrodes 701, 702, 703, and 704 and Figure 1 The electrodes are basically the same, so only the different parts will be described in detail.

[0069] like Figures 3 to 5 As shown, the first groove S2 and the second groove S3 can be formed into various shapes to facilitate the movement of electrolytes. For example... Figures 3 to 5 As shown, when the grooves are formed, the lengths of the grooves S2 and S3 are increased, which increases the time it takes for the electrolyte to reach the central hole. However, the area of ​​the active material layer moving along the grooves S2 and S3 can also be increased, thereby allowing the electrolyte to diffuse evenly throughout the entire active material layer.

[0070] Therefore, depending on the impregnation rate and amount of electrolyte, pores and their size and planar shape can be formed.

[0071] Reference Figure 3 The electrode 701, the first groove S2 and the second groove S3 can be tilted relative to the imaginary or virtual center line Y at a given angle θ. In this case, the angle θ can be in the range of about -50 degrees to about 50 degrees.

[0072] Reference Figure 4 and Figure 5 The first groove S2 and the second groove S3 may include curves.

[0073] For example, refer to Figure 4 The electrode 702, the first groove S2 and the second groove S3 may have curves such as arcs, and the first groove S2 and the second groove S3 may be bent in directions facing each other.

[0074] Reference Figure 5The electrode 703, the first groove S2 can have a shape formed by arcs bending in different directions, and can have a shape generally resembling the letter "S". The second groove S3 can be formed symmetrical or substantially symmetrical with respect to an imaginary or virtual center line Y with respect to the first groove S2. In this case, the first groove S2 and the second groove S3 can be compared... Figure 5 The electrode is bent more frequently, but because the electrolyte moves slowly, the electrolyte is impregnated slowly across the entire electrode, which can lead to a deterioration in yield.

[0075] Therefore, the bending length and degree can be adjusted according to the required impregnation speed, impregnation amount, etc.

[0076] For example, such as Figure 6 As shown, when the groove is formed in an inclined or curved shape, an external area "A" without grooves or holes may appear at the two edges of the active material layer.

[0077] Therefore, as Figure 6 As shown, an additional hole S1 can be formed in the outer region A, but the type of hole or groove is not limited to this, and grooves S2 or S3 can be further formed depending on the size of the outer region A. For example, grooves S2 / S3 can be formed in the direction of electrolyte movement.

[0078] The dimensions of hole S1 and grooves S2 / S3 can be compared with Figures 1 to 5 The grooves S2 / S3 and the hole S1 shown are the same size.

[0079] Figure 7 This is a top plan view of electrodes included in a rechargeable battery according to another example embodiment.

[0080] like Figure 7 As shown, the electrode 705 according to an example embodiment includes a substrate 70 and an active material layer 71 formed on one surface of the substrate 70. The electrode 705 may be a sheet-like electrode included in a stacked electrode assembly of a rechargeable battery, and may include an electrode coated region DA and an electrode uncoated region DB, wherein the electrode uncoated region DB may have a form that protrudes from the electrode coated region to lead current to the outside.

[0081] Figure 7 It is shown that the grooves S2 and S3 are formed to extend along the direction protruding from the uncoated area of ​​the electrode, but as Figures 3 to 6 As shown, grooves S2 and S3 can be formed in various shapes. In this case, the length direction of the groove can be the direction along which the electrolyte is injected into the rechargeable battery.

[0082] The impregnation amount and salt precipitation area were measured according to the comparative examples and embodiments, and are shown in Table 2 below.

[0083] In Comparative Examples 3, 4, 5, and 4, an active material layer having the same active material was formed, and a negative electrode comprising graphite was fabricated. In this case, the active material layer was formed only on one surface of the substrate, the thickness of the active material layer was approximately 60 μm, and the depth of the pores and grooves was approximately 30 μm.

[0084] Comparative Example 3 does not form holes and grooves separately, Comparative Example 4 only forms grooves, and Comparative Example 5 only forms holes, and as... Figure 1 As shown, in embodiment 4, both holes and grooves are formed.

[0085] Table 2:

[0086] Evaluation of impregnation amount: The immersion amount was evaluated by the change in weight. The electrode plate was cut into pieces 95 mm wide and 150 mm long, and immersed in a container with a water level of 1 cm. The change in weight before and after immersion was measured. In Comparative Examples 3, 4, 5, and 4, the electrode plate was immersed in the direction along which the electrolyte was injected into the rechargeable battery (i.e., the length direction of the groove), and the electrode plate was immersed in the electrolyte to a depth of about 3 mm. The change was measured after 1 hour.

[0087] Referring to Table 2 above, the weight change in Comparative Example 3, excluding the grooves and holes, is 0.156 g. Compared to Comparative Example 3, Comparative Examples 4, 5, and 4 have greater weight changes. This is because the impregnation amount in Comparative Examples 4, 5, and 4 is greater than that in Comparative Example 3.

[0088] In addition, it can be seen that Example 4 shows a larger weight change than Comparative Example 4 and Comparative Example 5, indicating that Example 4 has the largest impregnation amount.

[0089] Salt precipitation evaluation: Salt precipitation was evaluated by capturing images of the precipitation area. The electrode plate was cut into pieces 95 mm wide and 150 mm long, photographed, and analyzed. The captured images were converted into 8-bit black and white images using an image analysis program (e.g., ImageJ, manufactured by the National Institutes of Health), noise was removed, and the salt precipitation area was calculated from the black and white areas.

[0090] Referring to Table 2 above, compared to Example 4, which has a salt precipitation area of ​​1.3%, Comparative Examples 3, 4, and 5 have salt precipitation areas of 2.3%, 1.7%, and 1.5%, respectively. In other words, by forming pores and grooves as described in this disclosure, the salt precipitation area can be reduced, which can improve the performance of the rechargeable battery.

[0091] Figure 8 This is a schematic perspective view of a rechargeable battery according to an example embodiment. Figure 9 yes Figure 8 The image shows a longitudinal cross-sectional view of the rechargeable battery. Figure 10 yes Figure 8 The image shows a cross-sectional view of the rechargeable battery.

[0092] like Figure 8 and Figure 9 As shown, the rechargeable battery 110 according to an example embodiment includes a housing 120, an electrode assembly 130 housed inside the housing 120, and a cover assembly 140 assembled to an opening in the housing 120 to seal the housing 120. The cover assembly 140 includes a safety vent 101 for preventing or stopping the rechargeable battery 110 from exploding and an upper cover 104 for covering the safety vent 101.

[0093] Electrode assembly 130 includes a stacked (e.g., sequentially stacked) positive electrode 131, a diaphragm 133, and a negative electrode 132. Electrode assembly 130 may be or include a wound cylindrical electrode core formed by stacking and winding the positive electrode 131, the diaphragm 133, and the negative electrode 132.

[0094] The positive electrode 131 includes a positive electrode substrate, an electrode-coated region on which a positive electrode active material layer is formed, and an uncoated region of the positive electrode substrate that is "as is" exposed because no positive electrode active material layer is formed thereon. The positive electrode substrate may be formed of or comprise a thin conductive metal plate and serve as a current collector, and may be or comprise, for example, aluminum. The positive electrode tab 135 may be connected to the uncoated region of the electrode, and the positive electrode tab 135 may be made of the same material (e.g., aluminum) as the positive electrode substrate or may comprise the same material (e.g., aluminum) as the positive electrode substrate.

[0095] The positive electrode active material layer can be formed on one or both surfaces of the positive electrode substrate. The positive electrode active material layer includes a positive electrode active material and may also include a binder and / or a conductive material. The content of the positive electrode active material in the positive electrode active material layer can range from about 90 wt% to about 99.5 wt% relative to 100 wt% of the positive electrode active material layer, and the content of the binder and conductive material can each range from about 0.5 wt% to about 5 wt% relative to 100 wt% of the positive electrode active material layer.

[0096] Positive electrode active material As a positive electrode active material, compounds capable of reversibly inserting and deintercalating lithium ions (lithium-intercalating compounds) can be used. For example, at least one of the composite oxides of lithium and metals such as or including at least one of cobalt, manganese, nickel and combinations thereof can be used.

[0097] The composite oxide can be or includes lithium transition metal composite oxides, and examples include at least one of lithium nickel oxide, lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate compounds, cobalt-free lithium nickel manganese oxide, and combinations thereof.

[0098] For example, a compound represented by any of the following chemical formulas can be used. 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); Li a Mn 2-b X b O 4-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Ni 1-b-c Co b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni 1-b- c Mn b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni b Co c L 1 d G e O2 (0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); Li a NiG b O2 (0.90≤a≤1.8, 0.001≤b≤0.1); Li a CoG b O2 (0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-b G b O2 (0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn2G b O4 (0.90≤a≤1.8, 0.001≤b≤0.1); Lia Mn 1-g G g PO4 (0.90≤a≤1.8, 0≤g≤0.5); Li (3-f) Fe2(PO4)3 (0≤f≤2); Li a FePO4 (0.90≤a≤1.8).

[0099] In the above formula, A is or includes at least one of Ni, Co, Mn and combinations thereof; X is or includes at least one of Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements and combinations thereof; D is or includes at least one of O, F, S, P and combinations thereof; G is or includes at least one of Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V and combinations thereof; and L 1 It is or includes at least one of Mn, Al and combinations thereof.

[0100] For example, the positive electrode active material can be or includes a high-nickel positive electrode active material, which has a nickel content of 80 mol% or more, 85 mol% or more, 90 mol% or more, 91 mol% or more, or 94 mol% or more and 99 mol% or less, relative to 100 mol% of metals other than lithium in the lithium transition metal complex oxide. High-nickel positive electrode active materials can achieve high capacity and can be used in high-capacity, high-density lithium rechargeable batteries.

[0101] adhesive The binder is configured to facilitate the adhesion of the positive electrode active material particles to each other and to facilitate the adhesion of the positive electrode active material to the current collector. Representative examples of binders include, but are not limited to, at least one of the following: polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, epoxy resin, (meth)acrylate resin, polyester resin, nylon, etc.

[0102] conductive materials Conductive materials are configured to provide conductivity to the electrodes, and in the constructed battery, any material can be used as the electronically conductive material, as long as it does not cause adverse chemical changes in the battery. Examples of conductive materials include: carbon-based materials, such as at least one of natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, and carbon nanotube; metallic materials, including at least one of copper, nickel, aluminum, and silver, and in the form of metal powder or metal fiber; conductive polymers, such as polyphenylene derivatives; or mixtures thereof.

[0103] For example, the positive electrode can have the following characteristics: Figure 1 and Figure 2 The active material layers of the hole S1 and the grooves S2 and S3 shown in the figure.

[0104] Reference Figure 10 The positive electrode 131 includes a substrate 10 and active material layers 11 formed on two surfaces of the substrate, and pores and grooves can be formed in the active material layers 11, as per [reference to...]. Figure 1 and Figure 2 As discussed. For example, the groove S2 can be formed to extend along the direction in which the electrolyte is injected into the housing 120.

[0105] Return to reference Figure 8 and Figure 9 The negative electrode 132 includes a negative electrode substrate, an electrode coated region including a negative electrode active material layer formed on the negative electrode substrate, and an electrode uncoated region where no negative electrode active material layer is formed and the negative electrode substrate is exposed. The negative electrode substrate may be formed of or include a thin conductive metal plate and serve as a current collector, and may be, for example, copper. The negative electrode terminal 136 may be connected to the electrode uncoated region.

[0106] The negative electrode active material layer can be formed on one or both surfaces of the negative electrode substrate. The content of the negative electrode active material in the negative electrode active material layer can range from about 95 wt% to about 99 wt% relative to the total weight of the negative electrode active material layer.

[0107] The negative electrode active material layer may include a binder and may further selectively include a conductive material. The content of the binder in the negative electrode active material layer may range from about 1 wt% to about 5 wt% relative to the total weight of the negative electrode active material layer. Furthermore, when a conductive material is further included, the content of the negative electrode active material may range from about 90 wt% to about 98 wt%, the content of the binder may range from about 1 wt% to about 5 wt%, and the content of the conductive material may range from about 1 wt% to about 5 wt%.

[0108] Negative electrode active material As a negative electrode active material, it may include at least one of the following: materials capable of reversibly inserting and de-intercalating lithium ions, lithium metal, lithium metal alloys, materials doped or de-doped with lithium, and transition metal oxides.

[0109] Materials capable of reversibly inserting / deintercalating lithium ions can include carbon-based anode active materials, such as crystalline carbon, amorphous carbon, or combinations thereof. Examples of crystalline carbon include graphite, such as amorphous, plate-like, flake-like, spherical, or fibrous natural or artificial graphite, and examples of amorphous carbon include at least one of soft carbon, hard carbon, mesophase pitch carbides, calcined coke, etc.

[0110] The lithium metal alloy can be or includes a metal alloy of lithium with at least one of Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al and Sn.

[0111] Materials capable of doping and dedoping lithium can include Si-based or Sn-based anode active materials. Si-based anode active materials can be or include silicon, silicon-carbon composites, and silicon oxide (SiO₂). x The active material can be or includes at least one of the following: 0≤x≤2), Si-Q alloy (where Q is or includes at least one of alkali metals, alkaline earth metals, group 13 elements, group 14 elements (excluding Si), group 15 elements, group 16 elements, transition metals, rare earth elements, and combinations thereof). Sn-type negative electrode active materials can be or include at least one of Sn, SnO2, Sn-type alloys, and combinations thereof.

[0112] Silicon-carbon composites can be or include composites of silicon and amorphous carbon. According to one example embodiment, the silicon-carbon composite can be in the form of silicon particles, with amorphous carbon coated on the surface of the silicon particles. For example, the silicon-carbon composite can include secondary particles (cores) in which primary silicon particles are assembled and an amorphous carbon coating layer (shell) located on the surface of the secondary particles. Amorphous carbon can also be present between the primary silicon particles, such that, for example, the primary silicon particles can be coated with amorphous carbon. The secondary particles can be dispersed within an amorphous carbon matrix.

[0113] The silicon-carbon composite may further include crystalline carbon. For example, the silicon-carbon composite may include a core comprising crystalline carbon and silicon particles, and an amorphous carbon coating layer on the surface of the core.

[0114] Si-based or Sn-based anode active materials can be used in combination with carbon-based anode active materials.

[0115] adhesive The binder is configured to allow the negative electrode active material particles to adhere to each other and to allow the negative electrode active material to adhere to the current collector. The binder may be or include non-aqueous binders, aqueous binders, dry binders, or combinations thereof.

[0116] Non-aqueous adhesives include at least one of polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene-propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamide-imide, polyimide, and combinations thereof.

[0117] The waterborne adhesive may be or include at least one of the following: styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, (meth)acrylonitrile-butadiene rubber, (meth)acrylic rubber, butyl rubber, fluororubber, polyethylene oxide, polyvinylpyrrolidone, polyepoxychloropropane, polyphosphazene, poly(meth)acrylonitrile, ethylene propylene diene copolymer, polyvinylpyridine, chlorosulfonated polyethylene, latex, polyester resin, (meth)acrylic resin, phenolic resin, epoxy resin, polyvinyl alcohol, and combinations thereof.

[0118] When an aqueous binder is used as the negative electrode binder, the aqueous binder may further include a cellulose-based compound that provides viscosity. This cellulose-based compound may be included by mixing one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, or alkali metal salts thereof. The alkali metal may be or include at least one of Na, K, and Li.

[0119] Dry adhesives are polymeric materials capable of being fibrous, and may be or include at least one of, for example, polytetrafluoroethylene, polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, and combinations thereof.

[0120] conductive materials The conductive material is configured to provide conductivity to the electrodes and can be any electronically conductive material that does not cause adverse chemical changes in the battery configuration. Examples of conductive materials may include: carbon-based materials, such as at least one of natural graphite, synthetic graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, and carbon nanotubes; metallic materials, including at least one of copper, nickel, aluminum, and silver, and in the form of metal powder or metal fibers; conductive polymers, such as polyphenylene derivatives; or mixtures thereof.

[0121] For example, the negative electrode can have the following characteristics: Figure 1 and Figure 2 The active material layers of the pore S1 and the grooves S2 and S3 discussed.

[0122] Return to reference Figure 10The negative electrode 132 includes a substrate 20 and active material layers 21 formed on two surfaces of the substrate, and pores and grooves S2 can be formed in the active material layers 21, such as... Figure 1 and Figure 2 As described herein. For example, the groove may be formed to extend along the direction in which the electrolyte is injected into the housing 120.

[0123] Return to reference Figure 8 and Figure 9 The diaphragm 133 can be disposed between the positive electrode 131 and the negative electrode 132 and can provide insulation between them. The diaphragm 133 can be or include at least one of polyethylene, polypropylene, polyvinylidene fluoride and two or more layers thereof, and can include mixed multilayers such as polyethylene / polypropylene double layer diaphragm, polyethylene / polypropylene / polyethylene triple layer diaphragm, polypropylene / polyethylene / polypropylene triple layer diaphragm, etc.

[0124] Since the electrode assembly 130 can be wound around the center pin 134, the center pin 134 can be located at the center of the electrode assembly 130 and can be parallel or substantially parallel to the direction in which the electrode assembly 130 is inserted into the housing 120.

[0125] The center pin 134 can be in the form of a hollow cylindrical tube to minimize or reduce deformation, or maintain a shape close to its pre-deformation form, when subjected to full-surface compressive loads or localized impact loads applied from the outside of the rechargeable battery. Additionally, the center pin 134 can serve as a channel for gas generated internally. The center pin 134 can be omitted if necessary.

[0126] To minimize or reduce deformation caused by external impact, the center pin 134 may be formed of or comprise a material having a given stiffness, such as steel, steel alloys, aluminum, aluminum alloys, or a conductive metal. Therefore, since the center pin 134 is conductive, to keep both ends of the center pin 134 in an insulated state, a first insulating plate 137 may be disposed between the cover assembly 140 and the upper end of the center pin 134, and a second insulating plate 138 may be disposed between the bottom 121 of the housing 120 and the lower end of the center pin 134.

[0127] The first insulating plate 137 may have a through hole communicating with the interior of the center pin 134, a through hole through which the positive terminal piece 135 passes, and multiple through holes through which the electrolyte flows. The second insulating plate 138 may have a through hole communicating with the interior of the center pin 134 and a through hole through which the negative terminal piece 136 passes.

[0128] The housing 120 has an open side that allows the electrode assembly 130 to be inserted together with the electrolyte and may have a substantially the same shape as the electrode assembly 130. The housing 120 may include a circular bottom and cylindrical sides extending a given length upward from the bottom.

[0129] During the assembly process of the rechargeable battery, the upper part of the cylindrical housing can be open. Therefore, during the assembly process, electrode assemblies can be inserted into the cylindrical housing, and then electrolyte can be injected into the cylindrical housing. The housing 120 can be composed of or include at least one of steel, steel alloys, aluminum, and aluminum alloys.

[0130] The electrolyte is configured to allow the movement of lithium ions, which are generated through electrochemical reactions at the positive and negative electrodes inside the battery. The electrolyte may consist of or include lithium salts (such as LiPF6 and LiBF4) in organic solvents (such as EC, PC, DEC, and EMC). The electrolyte may be in liquid, solid, or gel form.

[0131] In the example embodiment, the grooves S2 and S3 are formed to extend along the direction of the injected electrolyte (or the direction of the inserted electrode assembly), so that the electrolyte can move quickly or easily along the grooves S2 and S3 to increase the immersion speed of the electrode.

[0132] In addition, the electrolyte, which can be moved quickly or easily through the groove, remains in the relatively centrally positioned hole, thereby increasing the amount of electrolyte impregnation on the electrode.

[0133] The rolled edge portion 123 and the crimped portion 124 may be located on the side portion 122 of the housing 120.

[0134] The rolled edge 123 is a portion that is deformed to be recessed toward the interior of the housing 120, and the crimping portion 124 is a portion that is deformed to bend the edge of the side portion 122 toward the interior of the rechargeable battery 110. The rolled edge 123 can reduce or suppress the movement of the electrode assembly 130, and the cover assembly 140 can be attached to the housing 120 via the crimping portion 124.

[0135] The cover assembly 140 includes a safety vent 101 for preventing or stopping the rechargeable battery 110 from exploding and an upper cover 104 covering the safety vent 101.

[0136] The cover assembly 140 may include a safety vent 101 with a notch 15, a lower cover 102 located on the side (lower side) of the safety vent 101 facing the electrode assembly 130, an annular insulating portion 103 located between the safety vent 101 and the lower cover 102, and an upper cover 104 located on the side (upper side) of the safety vent 101 opposite to the lower cover 102. The safety vent 101 may be referred to as a current interruption device (CID).

[0137] The center portion of the safety vent 101 may be thicker than the periphery surrounding the center portion, and the notch 15 may be positioned in the periphery of the safety vent 101.

[0138] The thickness of the central portion of the lower cover 102 may be less than the thickness of the peripheral portion surrounding its central portion, and at least one opening may be formed in the central portion and the peripheral portion of the lower cover 102.

[0139] The center portion of the safety vent 101 and the center portion of the lower cover 102 can be joined together by a method such as welding, and the safety vent 101 and the lower cover 102 can be spaced apart from each other in the rest of their portions except for their center portions.

[0140] The insulating portion 103 may surround the center of the safety vent 101 and the lower cover 102, and may be arranged between the safety vent 101 and the lower cover 102. The insulating portion 103 may be joined to the safety vent 101 and the lower cover 102 by means such as fusion (e.g., integrally joined).

[0141] Meanwhile, the positive terminal piece 135 of the electrode assembly 130 can be fixed to one side (or the lower side) of the lower cover 102, and the lower cover 102, the safety vent 101, and the upper cover 104 can be positively charged. The positive terminal piece 135 can be folded so that one surface of the lower cover 102 faces the positive terminal piece 135 to increase the contact area with the lower cover 102.

[0142] The top cover 104 may protrude outward to form a positive terminal that contacts an external device and allows current to flow to the outside, and may have a flat surface.

[0143] The negative terminal 136 can be connected to the uncoated area of ​​the negative electrode, thus protruding in the opposite direction to the positive terminal 135, and can be attached to the lower surface of the housing 120 by means of welding. Therefore, the housing 120 can be charged as a negative electrode, and the bottom 121 of the housing 120 can constitute the negative terminal.

[0144] The aforementioned cover assembly 140 can be joined to the side 122 of the housing 120 via an insulating washer 141. The insulating washer 141 can surround the edge of the safety vent 101 and the top cover 104, and can be pressed between the rolled edge 123 and the pressing part 124 of the housing 120.

[0145] During the use of the rechargeable battery 110, gas may be generated inside the casing 120 for various reasons, and the internal pressure of the rechargeable battery 110 may increase due to the gas.

[0146] When gas is generated, pressure is applied substantially continuously to the safety vent 101 through the opening of the lower cover 102, and under a certain pressure, the safety vent 101 deforms toward the outside (or upper side) of the cover assembly 140, causing the safety vent 101 and the lower cover 102 to separate from each other. At this time, the central portion of the lower cover 102 breaks off from the peripheral portion and rises together with the safety vent 101 while remaining attached to the central portion of the safety vent 101.

[0147] The current flow is blocked by the separation of the safety vent 101 from the lower cover 102. As the pressure continues to increase, the safety vent 101 ruptures around the notch 15, thereby releasing the internal gas. The internal gas is discharged to the outside of the rechargeable battery 110 through the vent formed in the upper cover 104.

[0148] While this disclosure has been described in conjunction with what are now considered to be exemplary embodiments, it will be understood that the disclosure is not limited to the disclosed exemplary embodiments, but rather is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

[0149] Description of reference numerals in the attached figures: 140: Cover component 70: Base 71: Active substance layer 110: Rechargeable batteries 120: Shell 130: Electrode assembly 131: Positive electrode 132: Negative electrode 133: Diaphragm 135: Positive terminal block 136: Negative terminal piece 140: Cover component 700, 701, 702, 703, 704, 705: Electrodes.

Claims

1. An electrode for a rechargeable battery, the electrode for the rechargeable battery comprising: Base; An active material layer is formed on the substrate; Pores are formed in the active material layer; as well as The first groove and the second groove are formed on both sides of the hole and spaced apart from the hole.

2. The electrode for a rechargeable battery according to claim 1, wherein, The sum of the lengths of the first groove and the second groove is in the range of 10% to 80% of the length of the active material layer in the first direction.

3. The electrode for a rechargeable battery according to claim 1, wherein, The spacing between the first groove and the second groove is in the range of 10% to 80% of the length of the active material layer in the first direction.

4. The electrode for a rechargeable battery according to claim 1, wherein, The electrode includes a plurality of holes having openings toward the surface of the active material layer, and the plurality of holes are arranged at regular intervals.

5. The electrode for a rechargeable battery according to claim 4, wherein, The pore has a shape in which its width narrows as the distance from the surface of the active material layer increases.

6. The electrode for a rechargeable battery according to claim 1, wherein, The depths of the first groove and the second groove are substantially constant.

7. The electrode for a rechargeable battery according to claim 6, wherein, The depths of the first groove and the second groove are shallower than the depth of the hole.

8. The electrode for a rechargeable battery according to claim 1, wherein, The center of the hole and the horizontal line that bisects the widths of the first and second grooves are on the same straight line.

9. The electrode for a rechargeable battery according to claim 1, wherein: The first groove and the second groove are inclined at an angle in the range of -50 degrees to 50 degrees relative to the virtual center line, which passes between the first groove and the second groove and bisects the length of the active material layer in a first direction.

10. The electrode for a rechargeable battery according to claim 1, wherein: The hole, the first groove, and the second groove are substantially symmetrical with respect to the virtual center line, which passes between the first groove and the second groove and bisects the length of the active material layer in a first direction.

11. The electrode for a rechargeable battery according to claim 1, wherein, The first groove and the second groove include curves.

12. The electrode for a rechargeable battery according to claim 1, wherein: The widths of the first and second grooves are in the range of 10 μm to 100 μm, and In the second direction, the spacing between adjacent first grooves and the spacing between adjacent second grooves are in the range of 70 μm to 300 μm.

13. The electrode for a rechargeable battery according to claim 1, wherein, The diameter of the hole is in the range of 10 μm to 100 μm.

14. A rechargeable battery, said rechargeable battery comprising: An electrode assembly includes a positive electrode, a negative electrode stacked with the positive electrode, and a diaphragm between the positive electrode and the negative electrode; Housing that houses the electrode assembly; Electrolytes are injected into the casing; as well as Cover assembly, sealing the housing; Wherein, at least one of the positive electrode and the negative electrode includes an active material layer having: a substrate; a first groove and a second groove formed on the substrate and spaced apart from each other in the direction along which the electrolyte is injected; and a hole located between the first groove and the second groove.

15. The rechargeable battery according to claim 14, wherein: The sum of the lengths of the first groove and the second groove is in the range of 10% to 80% of the length of the active material layer in the direction along which the electrolyte is injected.

16. The rechargeable battery according to claim 14, wherein: The spacing between the first groove and the second groove is in the range of 10% to 80% of the length of the active material layer in the direction along which the electrolyte is injected.

17. The rechargeable battery according to claim 14, wherein, Multiple pores are arranged at regular intervals in the active material layer.

18. The rechargeable battery according to claim 14, wherein: The first groove and the second groove are inclined at an angle in the range of -50 degrees to 50 degrees relative to the virtual center line, which passes between the first groove and the second groove and bisects the length of the active material layer along the direction of electrolyte injection.

19. The rechargeable battery according to claim 14, wherein: The hole, the first groove, and the second groove are substantially symmetrical with respect to a virtual center line that passes between the first groove and the second groove and bisects the length of the active material layer along the direction in which the electrolyte is injected.

20. The rechargeable battery according to claim 14, wherein, The first groove and the second groove include curves.

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