ACTIVE MATERIAL OF THE POSITIVE ELECTRODE, ELECTRODE AND BATTERY

Abstract

An active material of the positive electrode comprises secondary particles (2). Each of the secondary particles (2) comprises primary particles (1). Each of the primary particles (1) comprises an olivine-type phosphate compound. A portion of the surface of the secondary particle (2) has a depression (3). At the depression (3), the surface of the secondary particle (2) is concave. A cross-section of the secondary particle (2) satisfies the relationship "0.41 ≤ Sa / Ca ≤ 0.95". "Sa" represents the area of ​​the cross-section of the secondary particle (2). "Ca" represents the area of ​​the smallest circumcircle of the cross-section of the secondary particle (2).

Description

REFERENCE TO RELATED REGISTRATIONS

[0001] This non-provisional application is based on Japanese patent application No. 2024-181994, which was filed with the Japanese Patent Office on October 17, 2024, and the entire contents of which are hereby incorporated by reference. BACKGROUND area

[0002] The present invention relates to an active material of the positive electrode, an electrode and a battery. Description of the state of the art

[0003] International patent application WO 2020 / 065833 discloses primary particles comprising a lithium manganese phosphate compound and having a mean particle size of 60 nm or less. Summary

[0004] Olivine-type phosphate compounds were investigated as the active material for the positive electrode. Olivine-type phosphate compounds tend to exhibit insufficient performance or rate properties. Suggestions for improving these properties have been made, for example, by reducing the size of the primary particles. However, there is still room for improvement.

[0005] The aim of the present invention is to improve the performance characteristics.

[0006] The following describes the technical configuration and effects of the present invention. It should be noted that the mechanism of action according to the present invention involves assumptions. The mechanism of action does not limit the technical scope of the present invention. 1. One aspect of the present invention is an active material for the positive electrode. The active material of the positive electrode comprises secondary particles. Each of the secondary particles comprises primary particles. Each of the primary particles comprises an olivine-type phosphate compound. A portion of the surface of the secondary particle has a depression. At the depression, the surface of the secondary particle is recessed in the form of a concave area. A cross-section of the secondary particle satisfies the relationship "0.41 ≤ Sa / Ca ≤ 0.95". "Sa" represents the area of ​​the cross-section of the secondary particle. "Ca" represents the area of ​​the smallest circumcircle of the cross-section of the secondary particle.

[0007] The secondary particle is a group of multiple primary particles. Reducing the size of the primary particle shortens the ion diffusion path within it, which is expected to improve performance. However, this also means that the packing of primary particles within the electrode (the positive electrode layer) becomes denser, making it more difficult for the electrolyte solution to penetrate the electrode. Consequently, the desired performance characteristics may not be achieved. In the present invention, the secondary particle has a specific shape. More precisely, the surface of the secondary particle has a depression. Within the electrode, where the secondary particles are densely packed, this depression is expected to act as a diffusion path for the electrolyte solution. As a result, the performance characteristics are expected to be improved.It is conceivable that the ratio "Sa / Ca" correlates with the size of the well. It is conceivable that if the relationship "0.41 ≤ Sa / Ca ≤ 0.95" is satisfied, the well has a suitable size, thereby creating a diffusion path for the electrolyte solution within the electrode.

[0008] 2. The active material of the positive electrode according to point “1” above can, for example, comprise the following configuration. The cross-section of the secondary particle satisfies the relationship “d / R ≤ 1”. “d” represents the maximum depth of the well. “R” represents the radius of curvature of the well.

[0009] 3. The active material of the positive electrode according to point “1” or “2” above may, for example, comprise the following configuration. The cross-section of the secondary particle satisfies a relationship of “d / Sd ≤ 0.5”. “d” represents the maximum depth of the well. “Sd” represents the diameter of the smallest circumcircle.

[0010] 4. The active material of the positive electrode according to one of the preceding points “1” to “3” can, for example, comprise the following configuration. The cross-section of the secondary particle satisfies the relationships “D / Sd<1” and “1 <d / D“. „Sd“ steht für den Durchmesser des kleinsten Umkreises. „D“ steht für den Öffnungsdurchmesser der Vertiefung. „d“ steht für die maximale Tiefe der Vertiefung.

[0011] 5. The active material of the positive electrode according to any of the preceding points “1” to “4” may, for example, have the following configuration. The olivine-type phosphate compound comprises at least one compound selected from the group consisting of lithium manganese phosphate and lithium manganese iron phosphate.

[0012] Traditionally, lithium iron phosphate (LFP) is used as the olivine-type phosphate compound. Both lithium manganese phosphate (LMP) and lithium manganese iron phosphate (LMFP) tend to have a higher resistance than LFP. When using LMP and LMFP, it may be necessary to further reduce the size of the primary particles to achieve a practical resistance. It is conceivable that the secondary particle structure according to the present invention is suitable for both LMP and LMFP.

[0013] 6. One aspect of the present invention is an electrode. The electrode comprises a positive electrode layer. The positive electrode layer comprises the active material of the positive electrode according to any one of the preceding points “1” to “5”.

[0014] The positive electrode layer can also be referred to as the "active material layer of the positive electrode," "active composite material layer of the positive electrode," or similar terms. The "electrode" can be either a "monopolar electrode (a positive electrode)" or a "bipolar electrode," as long as it includes a positive electrode layer.

[0015] 7. One aspect of the present invention is a battery. The battery comprises the electrode according to point “6” above.

[0016] 8. The battery according to point “7” above may, for example, have the following configuration. The battery has a bipolar structure.

[0017] The bipolar structure can be formed by stacking bipolar electrodes. An improvement in performance characteristics can be expected with a bipolar structure.

[0018] The following describes an embodiment of the present invention (hereinafter referred to simply as "the present embodiment") and an example of the present invention (hereinafter referred to simply as "the present example"). It should be noted that neither the present embodiment nor the present example limits the technical scope of the present invention. The present embodiment and the present example serve in every respect for illustrative purposes. The present embodiment and the present example are not limiting. The technical scope of the present invention includes all modifications in the sense and scope that correspond to the terms of the claims. For example, it is originally intended that all configurations of the present embodiment can be optionally combined.

[0019] The foregoing and other objectives, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a first conceptual view illustrating a secondary particle according to the present embodiment. Fig. Figure 2 is a second conceptual view illustrating a secondary particle according to the present embodiment. Fig. Figure 3 is a third conceptual view illustrating a secondary particle according to the present embodiment. Fig. Figure 4 is a fourth conceptual view illustrating a secondary particle according to the present embodiment. Fig. Figure 5 is a schematic flowchart illustrating a method for producing active material of the positive electrode according to the present embodiment. Fig. Figure 6 is a schematic perspective view illustrating a battery according to the present embodiment. Fig. Figure 7 is a schematic view of a cross-section along line VII-VII in Fig. 6. Fig. Figure 8 is a table showing the test results. Fig. Figure 9 is a temperature profile during calcination. DESCRIPTION OF PREFERRED FORMS - Terms and expressions -

[0020] Expressions such as "comprise," "contain," and "exist," as well as other similar terms, are open expressions. In a configuration expressed by an open expression, an additional component may or may not be included alongside an essential component. The expression "consist of" is a closed expression. However, even in a configuration expressed by a closed expression, impurities that are present under normal circumstances, as well as an additional element that is irrelevant to the technology in question, may be included. The expression "essentially consist of" is a semi-closed expression. A configuration expressed by a semi-closed expression tolerates the addition of an element that does not substantially affect the fundamental, novel features of the technology in question.

[0021] Expressions like "can" and "may" do not mean "must" (obligation), but "there is a possibility" (tolerance).

[0022] With regard to multiple steps, operations, processes, and the like encompassed in various procedures, the order in which they are performed is not restricted to the order described, unless otherwise specified. For example, several steps may occur simultaneously. For example, several steps may be performed in reverse order.

[0023] Expressions like "first" and "second" are used solely to distinguish between multiple elements. Such expressions do not limit the scope of these elements. For example, these expressions are independent of the order and meaning of these elements.

[0024] Geometric terms should not be interpreted solely according to their literal meaning. Examples of geometric terms include "parallel," "vertical," "orthogonal," and the like. As long as essentially the same or similar functions are maintained, for example, the relative direction, angle, distance, and the like may vary. Each geometric term in this description may encompass tolerances and / or errors related to design, operation, production, and / or the like. The dimensional relationships in the individual figures do not necessarily correspond to the actual dimensional relationships. To facilitate understanding for the reader, the dimensional relationships in the individual figures may have been modified. For example, length, width, thickness, and the like may have been changed. A part of a particular configuration may have been omitted.

[0025] A singular form can also include its plural form unless otherwise specified. For example, a particle can mean a plurality of particles, a group of particles, and a powdery or granular material. "A plurality of particles" can also be referred to as a "group of particles."

[0026] A range of numbers such as "from m to n %" includes both the upper and lower bounds unless otherwise specified. That is, "from m to n %" means a range of numbers "not less than m % and not more than n %". Furthermore, "not less than m % and not more than n %" also includes "more than m % and less than n %". "Not less than" and "not more than" are each represented by an inequality sign with an equals sign, e.g., "≤", ≥. "More than" and "less than" are each represented by an inequality sign without an equals sign, e.g., "<", >. Any numerical value selected from a given range can be used as a new upper bound or a new lower bound.For example, any numerical value from a given range of numbers can be combined with any numerical value described elsewhere in this description, or in a table or drawing, to define a new range of numbers.

[0027] All numerical values ​​are considered modified by the term "approximately." The term "approximately" may mean, for example, ±5%, ±3%, ±1%, and / or the like. Any numerical value may be an approximation that may vary depending on the implementation configuration of the technique in question. Any numerical value may be expressed in significant figures. Unless otherwise specified, any measurement may be the mean obtained from multiple rounds of measurement. The number of measurement rounds may be 3 or more, 5 or more, or 10 or more. In general, the greater the number of measurement rounds, the more reliable the mean is expected to be. Any measurement may be rounded based on the number of significant figures. Any measurement may, for example, include an error that occurs due to the identification limit of the measuring instrument.

[0028] A device, software, and / or similar equipment used to measure various values ​​and the like is merely an example. It is possible to use a product similar to the device and / or similar equipment presented as an example. If a similar product is used, the measurement conditions can be adjusted to suit the device.

[0029] Fig. Figure 1 is a first conceptual view illustrating a secondary particle according to the present embodiment. Fig. Figure 2 is a second conceptual view illustrating a secondary particle according to the present embodiment. Fig. 2 is a concept of a cross-section of a in Fig. The secondary particle 2 shown in Figure 1 is evaluated in a cross-sectional image from a scanning electron microscope (SEM). The cross-sectional SEM image can be obtained, for example, by the procedure described below. For example, 1 g of a positive electrode active material (powder) is dispersed in a mixture (10 g) of an epoxy resin (trade name "EPOTEX JP," manufactured by Nisshin-EM) as the main agent and a curing agent to form a dispersion. The resulting dispersion is stirred and mixed for 1 minute using a mixer (trade name "Awatori-Rentaro" (THINKY MIXER), manufactured by Thinky). The stirring speed can be, for example, approximately 2000 rpm. The dispersion is subjected to vacuum degassing. After vacuum degassing, the dispersion is transferred to a round, tubular resin container.The dispersion is left to stand for one day to allow the epoxy resin to cure. After curing, the hardened product undergoes wet polishing, producing a cross-sectional sample with a uniform and smooth cross-section. This uniform and smooth cross-section is examined using a scanning electron microscope (SEM) to obtain a cross-sectional image of the active material of the positive electrode. Measurements of dimensions and areas within the SEM cross-section, curve fitting, and similar analyses can be performed using image analysis software. For example, ImageJ and / or similar software can be used.

[0030] Within the cross-sectional SEM image, 10 secondary particles 2, each with one depression 3, can be randomly selected. Each of the values ​​described below (“Sa”, “Ca”, “d”, “R”, “D”, “Sd”) is measured for 10 secondary particles. The arithmetic mean of these 10 measurements is taken. If a secondary particle 2 has multiple depressions 3, “d”, “R”, and “D” are each the values ​​of the deepest depression 3.

[0031] The area “Sa” is the area of ​​a cross-section of the secondary particle 2. In other words, the area “Sa” is the area of ​​a region defined by the contour (the solid line in Fig. 2) is surrounded by the secondary particle 2. The area within the cross-sectional SEM image is determined by counting the pixels.

[0032] The area "Ca" refers to the area of ​​a least circumcircle (C0) of the secondary particle 2. "Less than circumcircle" refers to the smallest circle among the circles that circumscribe or surround the secondary particle 2. The diameter "Sd" is the diameter of the least circumcircle. Fig. 2 is the smallest circumcircle (C0), slightly shifted from the contour of the secondary particle 2 for the sake of simplicity.

[0033] The depression 3 refers to a portion of the surface of the secondary particle 2 that is indented inwards. The contour of the depression 3 is a concave curve. The depression 3 can also be referred to as a "crater" or similar feature. The maximum depth "d" is the shortest distance between a point on the contour of the depression 3, where the contour is furthest from a line connecting both ends of the opening of the depression 3, and that line. The length of the line connecting both ends of the opening is the opening diameter "D".

[0034] The radius of curvature “R” is the radius of curvature of depression 3. A circle (C1) is fitted to the contour of depression 3. The fitting of the circle (C1) is performed such that the portion of the circle in contact with the contour of depression 3 is maximized. The radius of the circle is considered the radius of curvature “R”. The bottom region of depression 3 can be either flat or conical.

[0035] The "maximum Feret diameter" refers to the length of the long side of the smallest circumscribing or surrounding rectangle (either oblong or square) that encircles or surrounds the particle. If the smallest circumscribing rectangle is square, the length of the long side refers to the length of one side. The maximum Feret diameter of a primary particle can be measured, for example, in a transmission electron microscopy (TEM) image.

[0036] “D50” refers to a particle size in the volume-based particle size distribution of powder, measured by laser diffraction, where the cumulative frequency reaches 50%.

[0037] A stoichiometric formula is a typical example of a compound. A compound can have a non-stoichiometric composition. For example, "Al₂O₃" is not limited to a compound where the ratio of the amounts of substance (the molar ratio) is "Al / O = 2 / 3". "Al₂O₃" represents a compound containing Al and O in any ratio of amounts of substance, unless otherwise specified. For example, the compound may be doped with a trace element. Part of the Al and / or O may be replaced by another element.

[0038] The chemical composition of a compound can be measured using inductively coupled plasma atomic emission spectroscopy (ICP-AES). A sample (e.g., active material of the positive electrode) in a quantity of 0.1 g is dissolved in a mixed acid (10 ml) of hydrochloric and sulfuric acid to prepare a sample solution. The sample solution is diluted to a suitable concentration using a volumetric flask. After dilution, the composition analysis is performed with an ICP-AES instrument. For example, a product with the trade name "PS3520 UVDD II (manufactured by Hitachi High-Tech Science)" and / or similar can be used.

[0039] "Derivative" refers to a compound that can be derived from its original compound by at least one partial modification selected from the group consisting of the introduction of a functional group, the exchange of atoms, oxidation, reduction, and other chemical reactions. The position of the modification can be one or multiple positions. "Substituent" can include at least one selected from the group consisting of an alkyl group, alkenyl group, alkynyl group, cycloalkyl group, unsaturated cycloalkyl group, aromatic group, heterocyclic group, halogen atom (F, Cl, Br, I, etc.).), OH group, SH group, CN group, SCN group, OCN group, Nitro group, Alkoxy group, unsaturated alkoxy group, Amino group, Alkylamino group, Dialkylamino group, Aryloxy group, Acyl group, Alkoxycarbonyl group, Acyloxy group, Aryloxycarbonyl group, Acylamino group, Alkoxycarbonylamino group, Aryloxycarbonylamino group, Sulfonylamino group.

[0040] Sulfamoyl group, carbamoyl group, alkylthio group, arylthio group, sulfonyl group, sulfinyl group, ureido group, phosphoramide group, sulfo group, carboxy group, hydroxamic acid group, sulfino group, hydrazino group, imino group, silyl group, and the like. These substituents can be further substituted. If two or more substituents are present, these substituents can be the same or different from each other. A plurality of substituents can be linked together to form a ring. - Active material of the positive electrode or active material for the positive electrode -

[0041] The active material of the positive electrode comprises secondary particles 2. The active material of the positive electrode can be a powder comprising a plurality of secondary particles 2. The D50 value of the active material of the positive electrode can be, for example, 5 µm or more, 10 µm or more, 15 µm or more, or 20 µm or more. The D50 value of the active material of the positive electrode can be, for example, 30 µm or less, 25 µm or less, 20 µm or less, 15 µm or less, or 10 µm or less.

[0042] The secondary particle 2 has a depression 3. As long as it includes secondary particles 2 with a depression 3, the active material of the positive electrode can also contain secondary particles that do not have a depression 3. The numerical proportion of secondary particles, each having a depression 3, among all secondary particles contained in the active material of the positive electrode can be, for example, 5% or more, or 10% or more, or 20% or more, or 30% or more, or 40% or more, or 50% or more, or 60% or more, or 70% or more, or 80% or more, or 90% or more.The numerical proportion of secondary particles, each having a depression 3, to all secondary particles contained in the active material of the positive electrode may, for example, be 100% or less, or 90% or less, or 80% or less, or 70% or less, or 60% or less, or 50% or less, or 40% or less, or 30% or less, or 20% or less, or 10% or less.

[0043] The depression 3 is formed on a portion of the surface of the secondary particle 2. The secondary particle 2 can have only one depression 3. The secondary particle 2 can have multiple depressions 3. The number of depressions 3 of a secondary particle 2 can be, for example, 2 or more, 4 or more, 6 or more, or 8 or more. The number of depressions 3 of a secondary particle 2 can be, for example, 10 or fewer, 8 or fewer, 6 or fewer, 4 or fewer, or 2 or fewer.

[0044] The recess 3 is concave. The opening of recess 3 can be circular. The roundness of the opening can be, for example, 0.85 or more, 0.90 or more, or 0.95 or more. The roundness of the opening can also be, for example, 1 or less, 0.95 or less, or 0.90 or less. The roundness of the opening is determined by the following equation. ψ=4πS / L2 ψ: Circularity π: Circular constant S: Area of ​​the opening L: Circumference of the opening (length of the opening's contour)

[0045] Circularity refers to the arithmetic mean of 10 or more openings.

[0046] The area “Sa” of the cross-section of the secondary particle 2 is divided by the area of ​​the smallest circumcircle of the cross-section of the secondary particle 2, thereby calculating the ratio “Sa / Ca”. In the present embodiment, the relationship “0.41 ≤ Sa / Ca ≤ 0.95” is satisfied. If this relationship is satisfied, an improvement in the flow properties can be expected. The ratio “Sa / Ca” can be, for example, 0.64 or more, or 0.74 or more. The ratio “Sa / Ca” can be, for example, 0.74 or less, or 0.64 or less. The ratio “Sa / Ca” can, for example, be between 0.50 and 0.90, or between 0.60 and 0.85.

[0047] The maximum depth “d” of recess 3 is divided by the radius of curvature “R” of recess 3, thus calculating the ratio “d / R”. For example, the relationship “d / R ≤ 1” may be satisfied. The ratio “d / R” may be, for example, 0.8 or less, 0.6 or less, 0.4 or less, or 0.2 or less. The ratio “d / R” may also be, for example, greater than 0, 0.2 or more, 0.4 or more, 0.6 or more, or 0.8 or more.

[0048] The maximum depth “d” of the depression 3 is divided by the diameter “Sd” of the smallest circumcircle of the secondary particle 2, thus calculating the ratio “d / Sd”. For example, the relationship “d / Sd ≤ 0.5” may be satisfied. The ratio “d / Sd” may be, for example, 0.4 or less, 0.3 or less, 0.2 or less, or 0.1 or less. The ratio “d / Sd” may, for example, be greater than 0, greater than 0.1, greater than 0.2, greater than 0.3, or greater than 0.4.

[0049] The opening diameter “D” of the recess 3 is divided by the diameter “Sd” of the smallest circumcircle of the secondary particle 2, thus calculating the ratio “D / Sd”. For example, the relationship “D / Sd < 1” may be satisfied. The ratio “D / Sd” may be, for example, 0.9 or less, 0.8 or less, 0.7 or less, 0.6 or less, 0.5 or less, 0.4 or less, 0.3 or less, or 0.2 or less. The ratio “D / Sd” may, for example, be 0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, 0.5 or more, 0.6 or more, 0.7 or more, 0.8 or more, or 0.9 or more.

[0050] The diameter “Sd” can be, for example, 5 µm or more, 10 µm or more, 15 µm or more, or 20 µm or more. The diameter “Sd” can also be, for example, 30 µm or less, 25 µm or less, 20 µm or less, 15 µm or less, or 10 µm or less.

[0051] The maximum depth “d” of recess 3 is divided by the opening diameter “D” of recess 3, thus calculating the ratio “d / D”. For example, the relationship “1 <d / D“ erfüllt sein. Das Verhältnis „d / D“ kann beispielsweise 1,2 oder mehr, 1,5 oder mehr, 1,8 oder mehr, 2,1 oder mehr, 2,4 oder mehr, 2,7 oder mehr, 3 oder mehr, 4 oder mehr, 5 oder mehr, 6 oder mehr, oder 7 oder mehr, oder 8 oder mehr, oder 9 oder mehr, oder 10 oder mehr betragen. Das Verhältnis „d / D“ kann beispielsweise 20 oder weniger, oder 10 oder weniger, oder 5 oder weniger, oder 3 oder weniger, oder 2 oder weniger betragen.

[0052] Fig. Figure 3 is a third conceptual view illustrating a secondary particle according to the present embodiment. In some of the present embodiments, the angle “θ” formed by the tangent to the recess 3 at the opening and the depth direction of the recess 3 (the dashed line) can be greater than 0° and less than 90°. For example, the angle “θ” can be 15° or more, 30° or more, 45° or more, 60° or more, or 75° or more. The angle “θ” can also be, for example, 75° or less, 60° or less, 45° or less, 30° or less, or 15° or less.

[0053] In some embodiments, at least part of the opening may protrude. The height of the protruding part from the surface of the secondary particle 2 may, for example, be between 0.001 d and 0.1 d. “d” refers to the maximum depth of the recess 3.

[0054] Fig. Figure 4 is a fourth conceptual view illustrating a secondary particle according to the present embodiment. The secondary particle 2 is an aggregate of primary particles 1. The secondary particle 2 comprises a plurality of primary particles 1. The primary particles 1 can be nanoparticles. The mean maximum Feret diameter of the primary particles 1 can, for example, be between 10 and 90 nm. The mean maximum Feret diameter of the particles 1 can, for example, be 20 nm or more, 30 nm or more, 40 nm or more, 50 nm or more, 60 nm or more, 70 nm or more, or 80 nm or more. The mean maximum Feret diameter of the particles 1 can, for example, be 80 nm or less or 60 nm or less. The mean value is calculated from the measurement results of 10 or more particles 1.

[0055] Carbon may adhere to at least part of the surface of the primary particle 1. The carbon may form a carbon layer 5. The amount of adhering carbon by mass fraction relating to the secondary particle 2 may be, for example, 0.1% or more, 0.5% or more, 1% or more, 2% or more, 3% or more, or 4% or more. The amount of adhering carbon by mass fraction relating to the secondary particle 2 may be, for example, 5% or less, 4% or less, or 3% or less.

[0056] Each of the primary particles 1 comprises an olivine-type phosphate compound. The olivine-type phosphate compounds comprise an olivine-type crystal phase. "Olivine-type" refers to a crystal structure belonging to the space group Pnma. The space group is identified by X-ray diffraction (XRD) of the powder. As long as it contains an olivine-type crystal phase, the olivine-type phosphate compounds can additionally contain any arbitrary crystal phase. For example, the olivine-type phosphate compounds can additionally comprise an amorphous phase and / or the like.

[0057] The olivine-type phosphate compounds can, for example, comprise at least one compound selected from the group consisting of LFP, LMP, and LMFP. The olivine-type phosphate compound can, for example, comprise at least one compound from the group consisting of LMP and LMFP. The LMFP, for example, can have a composition represented by the following general formula. Li a Mn 1-x Fe x PO4

[0058] The relationship "0.5 ≤ a ≤ 1.5" can be satisfied. For example, x can be greater than 0 or 0.05 or greater, or 0.1 or greater, or 0.2 or greater, or 0.3 or greater, or 0.4 or greater, or 0.5 or greater, or 0.6 or greater, or 0.7 or greater, or 0.8 or greater, or 0.9 or greater. Conversely, x can be less than 1 or 0.9 or less, 0.8 or less, 0.7 or less, 0.6 or less, 0.5 or less, 0.4 or less, 0.3 or less, 0.2 or less, or 0.1 or less.

[0059] The LMFP and / or similar device may be doped with an element other than lithium (Li), manganese (Mn), iron (Fe), phosphorus (P), and oxygen (O). The doping amount (the proportion of the amount of substance relative to the amount of Li) may, for example, range between 0.01 and 0.1.The dopant may comprise at least one of the following: boron (B), nitrogen (N), a halogen, silicon (Si), sodium (Na), magnesium (Mg), aluminum (Al), chromium (Cr), scandium (Sc), titanium (Ti), vanadium (V), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), selenium (Se), strontium (Sr), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), indium (In), lead (Pb), bismuth (Bi), antimony (Sb), tin (Sn), tungsten (W), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), Ytterbium (Yb), Lutetium (Lu) and an actinoid.

[0060] The active material of the positive electrode may further contain an additional component, as long as it comprises olivine-type phosphate compounds. This additional component may, for example, include lithium nickel compound oxide (LNO), lithium cobalt compound oxide (LCO), lithium manganese compound oxide (LMO), and / or the like. The mixing ratio (by mass) between the olivine-type phosphate compound and the additional component may, for example, be 9 / 1 to 1 / 9, 8 / 2 to 2 / 8, 7 / 3 to 3 / 7, or 6 / 4 to 4 / 6. The active material of the positive electrode can, for example, be a mixture of powder of the olivine-type phosphate compound and powder of the other component.

[0061] The LNO can, for example, have a structure belonging to the space group R-3m. The LNO can, for example, have a composition represented by the following general formula. Li a Ni x M 1-x O2

[0062] The formula satisfies the relationships 0.5 ≤ a ≤ 1.5, 0 ≤ x ≤ 1. For example, M can include at least one element from the group consisting of Co, Mn, and Al. For example, the relationship 0 < x ≤ 0.1, 0.1 ≤ x ≤ 0.2, 0.2 ≤ x ≤ 0.3, 0.3 ≤ x ≤ 0.4, 0.4 ≤ x ≤ 0.5, 0.5 ≤ x ≤ 0.6, 0.6 ≤ x ≤ 0.7, 0.7 ≤ x ≤ 0.8, 0.8 ≤ x ≤ 0.9, or 0.9 ≤ x ≤ 1 can be satisfied. For example, the relationship 0.6 ≤ a ≤ 1.4, 0.7 ≤ a ≤ 1.3, 0.8 ≤ a ≤ 1.2 or 0.9 ≤ a ≤ 1.1 may be satisfied.

[0063] The LNO can include at least one from the group consisting of LiNi 0,9 Co 0,1 O2, LiNi 0,9 Mn 0,1 Contains O2 and LiNiO2.

[0064] The LNO can be represented, for example, by the following general formula. A compound represented by the following general formula can also be referred to as "NCM". Li a Ni x Co y Mn z O2

[0065] The formula satisfies the relationships 0.5 ≤ a ≤ 1.5, 0 < x < 1, 0 < y < 1, 0 < z < 1, x + y + z = 1. For example, the relationship 0 < x ≤ 0.1, 0.1 ≤ x ≤ 0.2, 0.2 ≤ x ≤ 0.3, 0.3 ≤ x ≤ 0.4, 0.4 ≤ x ≤ 0.5, 0.5 ≤ x ≤ 0.6, 0.6 ≤ x ≤ 0.7, 0.7 ≤ x ≤ 0.8, 0.8 ≤ x ≤ 0.9, or 0.9 ≤ x < 1 can be satisfied. For example, the relationship 0 <y≤0,1, 0,1≤y≤0,2, 0,2≤y≤0,3, 0,3≤y≤0,4, 0,4≤y≤0,5, 0,5≤y≤0,6, 0,6≤y≤0,7, 0,7≤y≤0,8 0,8 ≤ y ≤ 0,9 oder 0,9 ≤ y < 1 erfüllt sein. Beispielsweise kann die Beziehung 0<z≤0,1, 0,1≤z≤0,2, 0,2≤z≤0,3, 0,3≤z≤0,4, 0,4≤z≤0,5, 0,5≤z≤0,6, 0,6≤z≤0,7, 0,7≤z≤0,8, 0,8 ≤ z ≤ 0,9 oder 0,9 ≤ z < 1 erfüllt sein.

[0066] NCM can include at least one of the group consisting of LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2, LiNi 0,4 Co 0,3 Mn 0,3 O2, LiNi 0,3 Co 0,4 Mn 0,3 O2, LiNi 0,3 Co 0,3 Mn 0,4 O2, LiNi 0,5 Co 0,2 Mn 0,3 O2, LiNi 0,5 Co 0,3 Mn 0,2 O2, LiNi 0,5 Co 0,4 Mn 0,1 O2, LiNi 0,5 Co 0,1 Mn 0,4 O2, LiNi 0,6 Co 0,2 Mn 0,2 O2, LiNi 0,6 Co 0,3 Mn 0,1 O2, LiNi 0,6 Co 0,1 Mn 0,3 O2, LiNi 0,7 Co 0,1 Mn 0,2 O2, LiNi 0,7 Co 0,2 Mn 0,1 O2, LiNi 0,8 Co 0,1 Mn 0,1 O2 and LiNi 0,9 Co 0,05 Mn 0,05 O2.

[0067] The LNO can be represented, for example, by the following general formula. A compound represented by the following general formula can also be referred to as "NCA". Li a Ni x Co y Al z O2

[0068] The formula satisfies the relationships 0.5 ≤ a ≤ 1.5, 0 < x < 1, 0 < y < 1, 0 < z < 1, x + y + z = 1. For example, the relationship 0 <x≤0,1, 0,1≤x≤0,2, 0,2≤x≤0,3, 0,3≤x≤0,4, 0,4≤x≤0,5, 0,5≤x≤0,6, 0,6≤x≤0,7, 0,7≤x≤0,8, 0,8 ≤ x ≤ 0,9 oder 0,9 ≤ x < 1 erfüllt sein. Beispielsweise kann die Beziehung 0 < y ≤ 0,1, 0,1 ≤ y ≤ 0,2, 0,2 ≤ y ≤ 0,3, 0,3 ≤ y ≤ 0,4, 0,4 ≤ y ≤ 0,5, 0,5 ≤ y ≤ 0,6, 0,6 ≤ y ≤ 0,7, 0,7 ≤ y ≤ 0,8, 0,8 ≤ y ≤ 0,9 oder 0,9 ≤ y < 1 erfüllt sein. Beispielsweise kann die Beziehung 0<z≤0,1, 0,1≤z≤0,2, 0,2≤z≤0,3, 0,3≤z≤0,4, 0,4≤z≤0,5, 0,5 ≤ z ≤ 0,6, 0,6 ≤ z ≤ 0,7, 0,7 ≤ z ≤ 0,8, 0,8 ≤ z ≤ 0,9 oder 0,9 ≤ z < 1 erfüllt sein.

[0069] NCA can, for example, include at least one from the group consisting of LiNi 0,7 Co 0,1 Al 0,2 O2, LiNi 0,7 Co 0,2 Al 0,1 O2, LiNi 0,8 Co 0,1 Al 0,1 O2, LiNi 0,8 Co 0,17 Al 0,03 O2, LiNi 0,8 Co 0,15 Al 0,05 O2 and LiNi 0,9 Co 0,05 Al 0,05 O2. - Method for producing the active material of the positive electrode -

[0070] Fig. Figure 5 is a schematic flowchart illustrating a process for producing an active material for the positive electrode according to the present embodiment. Hereinafter, “the process for producing an active material for the positive electrode according to the present embodiment” may simply be referred to as “the present process”. The present process comprises, for example, “(a) forming a slurry”, “(b) granulating”, and “(c) calcining”. (a) Formation of a slurry

[0071] The present process may, for example, involve the formation of a slurry containing a lithium compound, a manganese compound, an iron compound, a phosphate compound, and a solvent. The slurry may be formed, for example, by dispersing the materials in the solvent. For example, the lithium compound, the manganese compound, the iron compound, and the phosphate compounds may be prepared in quantities corresponding to the composition formula “Li a Mn 1-x Fe xThe composition ratio (in amount of substance) specified in PO4 (0.5 ≤ a ≤ 1.5, 0 ≤ x ≤ 1) must be met. The lithium compound may, for example, comprise lithium hydroxide and / or the like. The manganese compound may, for example, comprise manganese carbonate and / or the like. The iron compound may, for example, comprise iron phosphate and / or the like. The phosphate compound may, for example, comprise lithium dihydrogen phosphate and / or the like.

[0072] The slurry can be formulated to include a carbon material. This carbon material can form a carbon layer on the surface of each primary particle. The carbon material can contain, for example, glucose, sucrose, fructose, citric acid, and / or similar substances. The amount of carbon material added by mass relative to the raw material mixture (the sum of lithium compound, manganese compound, phosphate compounds, and iron compound) can range from, for example, 1% to 20%.

[0073] The solvent can include, for example, water and / or similar substances. The solids concentration of the slurry by mass fraction can be, for example, 20 to 40%. (b) Granulation

[0074] The present process can, for example, involve the formation of secondary particles by spray-drying the slurry. Each primary particle that forms the secondary particles contains a precursor of olivine-type phosphate compounds. For example, the slurry can be sprayed at high velocity during spray-drying. Collision can be induced between the secondary particles, allowing the formation of secondary particles, each with a collision scar. In other words, secondary particles with a depression can be formed. The spray dryer settings are selected to allow the formation of secondary particles, each with a collision scar. The inlet air temperature can be approximately 250 °C. The outlet air temperature can be, for example, between 100 and 130 °C. The inlet air pressure can be, for example, approximately 2.0 MPa.The spray pressure (nozzle pressure) can, for example, be between 0.5 and 0.6 MPa. (c) Calcination

[0075] The present method can include heat treatment of the secondary particles to produce an active material for the positive electrode. As a result of heating the precursor, an olivine-type phosphate compound can be synthesized from it.

[0076] Any heat treatment furnace (such as an electric furnace, a muffle furnace, and / or the like) can be used in this process. The heat treatment atmosphere can be, for example, an inert atmosphere, such as a nitrogen atmosphere, and / or the like. The heat treatment temperature can be, for example, between 400 and 700 °C. The heat treatment time can be, for example, between 4 and 6 hours. - Liquid battery or liquid-filled battery -

[0077] In some of the present embodiments, the battery may be a liquid battery. "Liquid battery" refers to a battery that comprises an electrolyte solution. For example, a polymer battery comprises an electrolyte solution and is therefore a liquid battery. In some of the present embodiments, the battery has a monopolar structure. In some of the present embodiments, the battery has a bipolar structure. As an example, a battery with a bipolar structure (a bipolar battery) is described.

[0078] Fig. Figure 6 is a schematic perspective view illustrating a battery according to the present embodiment. Fig. Figure 7 is a schematic view of a cross-section along line VII-VII in Fig. 6. In the following, “perpendicular to the plane direction” refers to the direction of a normal to the surface of a sheet-shaped element (such as a film layer or an electrode). “In-plane direction” refers to any direction orthogonal to the perpendicular to the plane direction. In the drawings relating to the present embodiment, the Z-axis direction corresponds to the perpendicular to the plane direction. The X-axis direction and the Y-axis direction are each examples of an in-plane direction.

[0079] A battery 100 comprises an outer packaging 90 and a power-generating element 50. The outer packaging 90 contains the power-generating element 50. The outer packaging 90 can, for example, comprise a first power collector plate 91, a first laminated film 92, a second laminated film 93, and a second power collector plate 94. The first laminated film 92 and the second laminated film 93 are joined to each other at one end in one direction within the plane. A sealing material (not shown) can be arranged between the first laminated film 92 and the second laminated film 93 in the portion between them.

[0080] At the ends in the stacking direction (Z-axis direction), the first current collector plate 91 and the second current collector plate 94 are each connected to the current-generating element 50. The first laminated film 92 is connected to the first current collector plate 91. The second laminated film 93 is connected to the second current collector plate 94. A sealing material (not shown) can be arranged between the current collector plate and the laminated film.

[0081] The current-generating element 50 comprises a plurality of bipolar electrodes 10. The bipolar electrodes 10 are stacked perpendicular to the plane (Z-axis direction). Perpendicular to the plane, each bipolar electrode 10 comprises a positive electrode layer 11, a current-collecting foil layer 13, and a negative electrode layer 12, in that order. In one direction in the plane (e.g., the X-axis direction), the current-collecting foil layer 13 extends outwards beyond the positive electrode layer 11 and the negative electrode layer 12. For example, the current-collecting foil layer 13 can extend outwards across the entire periphery in one direction in the plane beyond the positive electrode layer 11 and the negative electrode layer 12.

[0082] The current-collecting foil layer 13 is a conductor. For example, the current-collecting foil layer 13 can comprise a metal foil layer, an electrically conductive resin layer, and / or the like. For example, the current-collecting foil layer 13 can be formed by bonding an aluminum foil layer and a copper foil layer together. A carbon material can be applied to a surface of the current-collecting foil layer 13. The carbon material can, for example, comprise carbon black and / or the like.

[0083] The power-generating element 50 comprises a sealing material 30. At one end, in a plane, the sealing material 30 is attached to the current-collecting foil layer 13. For example, the sealing material 30 can be heat-sealed to the current-collecting foil layer 13. The sealing material 30 can also be provided along the entire circumference in a plane. The sealing material can, for example, comprise a resin material and / or the like. The sealing material 30 seals the gaps between current-collecting foil layers 13 that are adjacent to each other in a perpendicular direction. The gaps between the current-collecting foil layers 13 are thus sealed by the sealing material 30, forming cells 40. A cell 40 is the smallest unit component of the power-generating element 50. Since it comprises a plurality of cells 40, the battery 100 can also be referred to as a "bipolar module".Each of the cells 40 is hermetically sealed. The cells 40 are separated from each other. Each of the cells 40 comprises a positive electrode layer 11, a separator 20, a negative electrode layer 12, and an electrolyte solution. Positive electrode layer

[0084] The positive electrode layer 11 adheres to one side of the current-collecting foil layer 13. For example, a groove may be formed in the positive electrode layer 11. The positive electrode layer 11 may, for example, be formed in strips. The positive electrode layer 11 comprises active material of the positive electrode. That is, the battery 100 comprises active material of the positive electrode. The details of the active material of the positive electrode are as described above.

[0085] In addition to the active material of the positive electrode, the positive electrode layer 11 may, for example, contain a conductive material, a binder, and the like. The amount of conductive material to be used may, for example, be 0.1 to 10 parts by mass, based on 100 parts by mass of the active material of the positive electrode. The conductive material may comprise any components. The conductive material may include at least one component from the group consisting of graphite, carbon black (AB), Ketjenblack (registered trademark), vapor-grown carbon fibers (VGCF), carbon nanotubes (CNTs), and graphene flakes (GF).

[0086] The amount of binder to be used can be, for example, 0.1 to 10 parts by mass, based on 100 parts by mass of the active material of the positive electrode. The binder can comprise any components. The binder can include at least one component from the group consisting of polyvinylidene fluoride (PVdF), vinylidene fluoride-hexafluoropropylene copolymer (PVdF-HFP), polytetrafluoroethylene (PTFE), carboxymethylcellulose (CMC), polyacrylic acid (PAA), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyoxyethylene alkyl ethers, and derivatives thereof.

[0087] The positive electrode layer 11 may further comprise an inorganic filler, an organic filler, a solid electrolyte, a surface modifier, a dispersant, a lubricant, a flame retardant, a protective agent, a flux, an adhesion promoter, an adsorbent, and / or the like. The active material layer of the positive electrode may, for example, contain polyoxyethylene allylphenyl ether phosphate, zeolite, silane coupling agents, MoS₂, WO₃, and / or the like. Negative electrode layer

[0088] The negative electrode layer 12 adheres to one side of the current-collecting foil layer 13. The negative electrode layer 12 is located on the side opposite the positive electrode layer 11. The area of ​​the negative electrode layer 12 can be larger than that of the positive electrode layer 11. The negative electrode layer 12 comprises an active material of the negative electrode.

[0089] The active material of the negative electrode can be in particle or film form, for example. The D50 value of the active material of the negative electrode can be, for example, 1 µm or more, 5 µm or more, or 10 µm or more. Alternatively, the D50 value of the active material of the negative electrode can be, for example, 30 µm or less, 20 µm or less, 15 µm or less, or 10 µm or less.

[0090] The active material of the negative electrode can comprise any components. The active material of the negative electrode can include at least one component selected from the group consisting, for example, of carbon-based active material, alloy-based active material, Si-C composite material, Li-metal, Li-based alloy, and lithium titanate. In some present embodiments, the battery can be a Li-metal negative electrode battery.

[0091] The carbon-based active material can, for example, include at least one element from the group consisting of graphite, soft carbon, and hard carbon. The term "graphite" refers collectively to both natural and synthetic graphite. The graphite can be a mixture of natural and synthetic graphite. The mixing ratio (mass ratio) can be, for example, "(natural graphite) / (synthetic graphite) = 1 / 9 to 9 / 1", "(natural graphite) / (synthetic graphite) = 2 / 8 to 8 / 2", or "(natural graphite) / (synthetic graphite) = 3 / 7 to 7 / 3".

[0092] The surface of the graphite can, for example, be covered with amorphous carbon. The surface of the graphite can, for example, be covered with another material. This other material can include at least one from the group consisting of P, W, Al, and O. The other material can include at least one from the group consisting of, for example, Al(OH)3, AlOOH, Al2O3, WO3, Li2CO3, LiHCO3, and Li3PO4.

[0093] The alloy-based active material can include at least one from the group consisting of Si, Li silicate, SiO, Si-based alloy, tin (Sn), SnO and Sn-based alloy.

[0094] SiO can be represented, for example, by the following general formula. SiO x

[0095] In the formula, the relationship is 0. <x<2 erfüllt. Beispielsweise kann die Beziehung 0,5 ≤ x ≤ 1,5 oder 0,8 ≤ x ≤ 1,2 erfüllt sein.

[0096] "Si-C composite material" refers to a composite material consisting of a carbon-based active material (such as graphite) and an alloy-based active material (such as silicon). For example, silicon microparticles may be dispersed within carbon particles. For example, silicon microparticles may be dispersed within graphite particles. For example, lithium silicate particles may be coated with a carbon material (such as amorphous carbon). separator

[0097] The separator 20 is capable of separating the positive electrode layer 11 from the negative electrode layer 12. The separator 20 is electrically insulating. The separator 20 can comprise at least one component from the group consisting of a resin film (a polymer film), an inorganic particle layer, and an organic particle layer. For example, the separator 20 can comprise a resin film and an inorganic particle layer.

[0098] The resin film is porous. The resin film can, for example, comprise a microporous film, a nonwoven fabric, and / or the like. The resin film contains a resin framework. The resin framework can, for example, be continuous in the form of a network. Gaps in the resin framework form pores. The resin film allows an electrolyte solution to penetrate it. The resin film can, for example, have a mean pore size of 1 µm or less. The resin film can have a mean pore size of 0.01 to 1 µm or of 0.1 to 0.5 µm. The "mean pore size" can be measured by mercury porosimetry. The resin film can, for example, have a Gurley value of 50 to 250 s / 100 cm². 3 exhibit. The "Gurley value" can be measured using a Gurley test procedure.

[0099] The resin film may comprise at least one substance selected from the group consisting, for example, of an olefin-based resin, a polyurethane-based resin, a polyamide-based resin, a cellulose-based resin, a polyether-based resin, an acrylic-based resin, a polyester-based resin, and the like. The resin film may also comprise at least one substance from the group consisting of polyethylene (PE), polypropylene (PP), polyamide (PA), polyamide-imide (PAI), polyimide (PI), aromatic polyamide (aramid), polyphenylene ether (PPE), and derivatives thereof. The resin film may be formed, for example, by stretching, phase separation, and / or the like. The resin film may have a thickness of, for example, 5 to 50 µm or 10 to 25 µm.

[0100] The resin film can have a single-layer structure. For example, the resin film can consist of a PE layer. The framework of a PE layer is made of PE. The PE layer can have a switching function. The resin film can, for example, have a multi-layer structure. The resin film can, for example, comprise a PP layer and a PE layer. The framework of a PP layer is made of PP. The resin film can, for example, have a three-layer structure. The plastic film can be formed, for example, by stacking a PP layer, a PE layer, and another PP layer in that order. The thickness of the PE layer can, for example, be between 5 and 20 µm. The thickness of the PP layer can, for example, be between 3 and 10 µm.

[0101] The inorganic particle layer can form on the surface of the resin film. The inorganic particle layer can form on only one side of the resin film or on both sides of the resin film. The inorganic particle layer can form on the side facing the positive electrode layer 11 or on the side facing the negative electrode layer 12. The inorganic particle layer can be formed on the surface of the positive electrode layer 11 or on the surface of the negative electrode layer 12.

[0102] The inorganic particle layer is porous. The inorganic particle layer comprises inorganic particles. The inorganic particles can also be referred to as "inorganic filler." The spaces between the inorganic particles form pores. The inorganic particle layer can have a thickness of, for example, 0.5 to 10 µm or 1 to 5 µm. The inorganic particles can, for example, include a heat-resistant material. The inorganic particle layer that includes a heat-resistant material is also referred to as an "HRL (Heat Resistance Layer)." The inorganic particles can include at least one from the group consisting of boehmite, aluminum oxide, zirconium oxide, titanium dioxide, magnesium oxide, silicon dioxide, and the like. The inorganic particles can have any shape.The inorganic particles can be, for example, spherical, rod-shaped, plate-shaped, fibrous, and / or the like. The inorganic particles can, for example, have a D50 of 0.1 to 10 µm or of 0.5 to 3 µm. The layer of inorganic particles can further contain a binder. The binder can comprise at least one from the group consisting of an acrylic-based resin, a polyamide-based resin, a fluorine-based resin, an aromatic polyether-based resin, a liquid crystal polyester-based resin, and the like.

[0103] Separator 20 can, for example, include an organic layer. Separator 20 can, for example, include an organic layer instead of a resin layer. Separator 20 can, for example, include an organic layer instead of an inorganic particle layer. Separator 20 can include both a resin layer and an organic particle layer. Separator 20 can include both an inorganic particle layer and an organic particle layer. Separator 20 can include the resin layer, the inorganic particle layer, and an organic particle layer.

[0104] The organic particle layer can have a thickness of, for example, 0.1 to 50 µm, 0.5 to 20 µm, 0.5 to 10 µm, or 1 to 5 µm. The organic particle layer comprises organic particles. The organic particles can also be referred to as "organic filler." The organic particles can include a heat-resistant material. The organic particles can include at least one material from the group consisting of PE, PP, PTFE, PI, PAI, PA, aramid, and the like. The organic particles can be, for example, spherical, rod-shaped, plate-shaped, fibrous, and / or the like. The organic particles can, for example, have a D50 of 0.1 to 10 µm or 0.5 to 3 µm.

[0105] Separator 20 can, for example, include a mixed layer. The mixed layer contains both inorganic and organic particles. electrolyte solution

[0106] The electrolyte solution is a liquid electrolyte. It contains a solute and a solvent. The concentration of the solute can be, for example, between 0.5 and 1 mol / L, between 1 and 1.5 mol / L, between 1.5 and 2 mol / L, between 2 and 2.5 mol / L, or between 2.5 and 3 mol / L. "mol / L" can also be expressed as "M". The solute includes a carrier salt (a lithium salt). The solute can, for example, be an inorganic acid salt, an imide salt, an oxalate complex, a halide, and / or the like. The solute may include at least one substance selected from the group consisting of LiPF6, LiBF4, LiClO4, LiAsF6, LiSbF6, LiN(SO2F)2 “LiFSI”, LiN(SO2CF3)2 “LiTFSI”, LiB(C2O4)2 “LiBOB”, LiBF2 (C2O4) “LiDFOB”, LiPF2(C2O4)2 “LiDFOP”, LiPO2F2, FSO3Li, Lil, LiBr and derivatives thereof.

[0107] The electrolyte solution may, for example, comprise a carbonate-based solvent (a carbonate ester-based solvent). The solvent may, for example, comprise a cyclic carbonate, a chain carbonate, a fluorinated carbonate, and / or the like. The solvent may include at least one from the group consisting of ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), monofluoroethylene carbonate (FEC), difluoroethylene carbonate, 4,4-difluoroethylene carbonate, trifluoroethylene carbonate, perfluoroethylene carbonate, fluoropropylene carbonate, difluoropropylene carbonate, and derivatives thereof.

[0108] The solvent can comprise a cyclic carbonate (such as EC, PC, FEC) and a chain carbonate (such as EMC, DMC, DEC). The mixing ratio between the cyclic carbonate and the chain carbonate (volume ratio) can be, for example, "(cyclic carbonate) / (chain carbonate) = 1 / 9 to 4 / 6", "(cyclic carbonate) / (chain carbonate) = 2 / 8 to 3 / 7", or "(cyclic carbonate) / (chain carbonate) = 3 / 7 to 4 / 6".

[0109] The solvent can comprise a cyclic carbonate (such as EC, PC) and a fluorinated cyclic carbonate (such as FEC). The mixing ratio between the cyclic carbonate and the fluorinated cyclic carbonate (volume ratio) can be, for example, "(cyclic carbonate) / (fluorinated cyclic carbonate) = 99 / 1 to 90 / 10" or "(cyclic carbonate) / (fluorinated cyclic carbonate) = 9 / 1 to 1 / 9" or "(cyclic carbonate) / (fluorinated cyclic carbonate) = 9 / 1 to 7 / 3" or "(cyclic carbonate) / (fluorinated cyclic carbonate) = 3 / 7 to 1 / 9".

[0110] The solvent may contain, for example, EC, FEC, EMC, DMC, and DEC. The volume ratio of these components may, for example, correspond to the following equation. VEC+VFEC+VEMC+VDMC+VDEC=10

[0111] In the equation above, V stands for EC , V FEC , V EMC , V DMC and V DECeach for the volume ratio of EC, FEC, EMC, DMC and DEC.

[0112] The relationships 1 ≤ V EC ≤ 4, 0 ≤ V FEC ≤ 3, V EC + V FEC ≤ 4, 0 ≤ V EMC ≤ 9, 0≤V DMC ≤9, 0≤V DEC ≤9, 6≤V EMC +V DMC +V DEC ≤9 are fulfilled. For example, the relationship 1≤V EC ≤2 or 2≤V EC ≤3 must be fulfilled. For example, the relationship 1≤V FEC ≤2 or 2≤V FEC ≤4 must be fulfilled. For example, the relationship 3≤V EMC ≤4 or 6≤V EMC ≤8 must be fulfilled. For example, the relationship 3≤V DMC ≤4 or 6≤V DMC ≤8 must be fulfilled. For example, the relationship 3≤V DEC ≤4 or 6≤V DEC ≤8 must be fulfilled.

[0113] The solvent may have a composition of “EC / EMC=3 / 7”, “EC / DMC=3 / 7”, “EC / FEC / DEC=1 / 2 / 7”, “EC / DMC / EMC=3 / 4 / 3”, “EC / DMC / EMC=3 / 3 / 4”, “EC / FEC / DMC / EMC=2 / 1 / 4 / 3”, “EC / FEC / DMC / EMC=1 / 2 / 4 / 3”, “EC / FEC / DMC / EMC=2 / 1 / 3 / 4”, “EC / FEC / DMC / EMC=1 / 2 / 3 / 4” (volume ratio) and / or the like.

[0114] The electrolyte solution may contain an ether-based solvent. The electrolyte solution may contain at least one of the following: tetrahydrofuran (THF), 1,4-dioxane (DOX), 1,3-dioxolane (DOL), 1,2-dimethoxyethane (DME), 1,2-diethoxyethane (DEE), hydrofluoroether (HFE), ethylglyme, triglyme, tetraglyme, and derivatives thereof.

[0115] The electrolyte solution may contain any additives. The amount added (the mass fraction of the total electrolyte solution) may be, for example, 0.01 to 5%, 0.05 to 3%, or 0.1 to 1%. The additive may include, for example, a solid electrolyte interphase (SEI) formation promoter, a selenium (SEL) formation inhibitor, a gas-forming agent, a charge inhibitor, a flame retardant, an antioxidant, an electrode protectant, a surfactant, and / or the like.

[0116] The additive may comprise at least one substance from the group consisting of vinylene carbonate (VC), vinylethylene carbonate (VEC), 1,3-propanesultone (PS), tert-amylbenzene, 1,4-di-tert-butylbenzene, biphenyl (BP), cyclohexylbenzene (CHB), ethylene sulfite (ES), ethylene sulfate (DTD), γ-butyrolactone, phosphazene compound, carboxylate esters [such as methyl formate (MF), methyl acetate (MA), methyl propionate (MP), diethyl malonate (DEM)], fluorobenzene (such as monofluorobenzene (FB), 1,2-difluorobenzene, 1,3-difluorobenzene, 1,4-difluorobenzene, 1,2,3-trifluorobenzene, 1,2,4-trifluorobenzene, 1,3,5-trifluorobenzene, 1,2,3,4-tetrafluorobenzene, 1,2,3,5-tetrafluorobenzene, 1,2,4,5-tetrafluorobenzene, pentafluorobenzene, hexafluorobenzene), fluorotoluene (such as 2-fluorotoluene, 3-fluorotoluene, 4-fluorotoluene, 2,3-difluorotoluene, 2,4-difluorotoluene, 2,5-difluorotoluene, 2,6-difluorotoluene, 3,4-difluorotoluene, octafluorotoluene), benzotrifluoride (such as benzotrifluoride, 2-fluorobenzotrifluoride,3-Fluorobenzotrifluoride, 4-Fluorobenzotrifluoride, 2-Methylbenzotrifluoride, 3-Methylbenzotrifluoride, 4-Methylbenzotrifluoride), fluoroxylene (such as 3-fluoro-o-xylene, 4-fluoro-o-xylene, 2-fluoro-m-xylene, 5-fluoro-m-xylene), sulfur-containing heterocyclic compounds (such as benzothiazole, 2-methylbenzothiazole, tetrathiafulvalene), nitrile compounds (such as adiponitrile, succinonitrile), phosphates (such as trimethyl phosphate, triethyl phosphate), carboxylic anhydrides (such as acetic anhydride, propionic anhydride, oxalic anhydride, succinic anhydride, maleic anhydride, phthalic anhydride, benzoic anhydride), alcohols (such as methanol, ethanol, n-propyl alcohol, ethylene glycol, Diethylene glycol monomethyl ether) and derivatives thereof.

[0117] The components described above as solutes and solvents can be used as trace components (additives). The additive can include at least one substance from the group consisting of LiBF4, LiFSI, LiTFSI, LiBOB, LiDFOB, LiDFOP, LiPO2F2, FSO3Li, Lil, LiBr, HFE, DOX, PC, FEC and derivatives thereof.

[0118] The electrolyte solution may contain an ionic liquid. The ionic liquid may contain at least one substance selected from the group consisting, for example, of a sulfonium salt, an ammonium salt, a pyridinium salt, a piperidinium salt, a pyrrolidinium salt, a morpholinium salt, a phosphonium salt, an imidazolium salt, and derivatives thereof.

[0119] In some embodiments, the battery may comprise a gelled electrolyte. In other words, the battery may be a polymer battery. The gelled electrolyte may comprise an electrolyte solution and a polymer material. The polymer material may form a polymer matrix. The polymer material may comprise at least one from the group consisting of PVdF, PVdF-HFP, polyacrylonitrile (PAN), PVdF-PAN, polyethylene oxide (PEO), polyethylene glycol (PEG), and derivatives thereof. - Solid state battery -

[0120] In some embodiments, the battery can be a solid-state battery. The solid-state battery can have a bipolar structure. The solid-state battery comprises a solid electrolyte instead of the electrolyte solution and the separator 20. A solid electrolyte can also be contained in the positive electrode layer 11 and the negative electrode layer 12. Instead of the separator 20, a solid electrolyte layer separates the positive electrode layer 11 from the negative electrode layer 12. The solid electrolyte layer comprises, for example, a solid electrolyte and a binder.

[0121] The solid electrolyte can be, for example, a powdered or granular material. The D50 value of the solid electrolyte can be, for example, 0.1 µm or more, 0.2 µm or more, 0.3 µm or more, 0.4 µm or more, 0.5 µm or more, 0.6 µm or more, 0.7 µm or more, 0.8 µm or more, 0.9 µm or more, or 1 µm or more. The D50 value of the solid electrolyte can also be, for example, 5 µm or less, 4 µm or less, 3 µm or less, 2 µm or less, or 1 µm or less.

[0122] The solid electrolyte may comprise at least one from the group consisting of a sulfide solid electrolyte, a halide solid electrolyte, an oxide solid electrolyte, a hydride solid electrolyte and a nitride solid electrolyte.

[0123] The sulfide solid electrolyte can comprise at least one component selected from the group consisting of an amorphous phase, a crystalline phase, and a glass-ceramic phase (crystallized glass). The crystalline phase can be, for example, of the argyrodite type, the LGPS type, and / or the like. The sulfide solid electrolyte comprises lithium (Li) and sulfur (S). In addition to Li and S, the sulfide solid electrolyte can include any other components.

[0124] The sulfide solid electrolyte may contain at least one component from the group consisting of Lil-LiBr-Li3PS4, Li2S-SiS2, Lil-Li2S-SiS2, Lil-Li2S-P2S5, Lil-Li2O-Li2S-P2S5, Lil-Li2S-P2O5, Lil-Li3PO4-P2S5, Li2S-GeS2-P2S5, Li2S-P2S5, Li 10 GeP2S 12 , Li4P2S6, Li7P3S 11 , Li3PS4 and Li7PS6, included.

[0125] For example, "Lil-LiBr-Li3PS4" refers to a sulfide solid electrolyte produced by mixing Lil, LiBr, and Li3PS4 in a freely selectable ratio of substances. The sulfide solid electrolyte can be produced, for example, by a mechanochemical process. The mixing ratio can be expressed by the number preceding each raw material. For example, "10Lil-15LiBr-75Li3PS4" means that the mixing ratio is "Lil / LiBr / Li3PS4 = 10 / 15 / 75 (in amount of substance)."

[0126] The sulfide solid electrolyte can, for example, have a composition represented by the following general formula. xLi2S-(1-x)P2S5

[0127] In the formula, x can be greater than 0, or 0.1 or more, or 0.2 or more, or 0.25 or more, or 0.3 or more, or 0.4 or more, or 0.5 or more, or 0.6 or more, or 0.7 or more, or 0.75 or more, or 0.8 or more, or 0.9 or more. For example, x can be 1 or less, or 0.9 or less, or 0.8 or less, or 0.7 or less, or 0.75 or less, or 0.6 or less, or 0.5 or less, or 0.4 or less, or 0.3 or less, or 0.2 or less, or 0.1 or less. For example, if x is 0.75, "xLi2S-(1-x)P2S5" can have a composition of Li3PS4.

[0128] The sulfide solid electrolyte can, for example, have a composition represented by the following general formula. yLil-zLiBr-(100-yz)[xLi2S-(1-x)P2S5]

[0129] In the formula, x can be, for example, 0.5 or more, 0.6 or more, 0.7 or more, 0.75 or more, 0.8 or more, or 0.9 or more. x can be, for example, 1 or less, 0.9 or less, 0.8 or less, 0.75 or less, 0.7 or less, or 0.6 or less. y can be, for example, 0 or more, 5 or more, 10 or more, 15 or more, 20 or more, or 25 or more. y can be, for example, 30 or less, 25 or less, 20 or less, 15 or less, 10 or less, or 5 or less. z can be, for example, 0 or more, 5 or more, 10 or more, 15 or more, 20 or more, or 25 or more. z can be, for example, 30 or less, 25 or less, 20 or less, 15 or less, 10 or less, or 5 or less.

[0130] The sulfide solid electrolyte can, for example, have a composition represented by the following general formula. Li 7-x-2y PS 6-x-y Xy

[0131] The formula satisfies the relationships "0<(7-x-2y)", "0<(6-xy)", "0≤x" and "0≤y". X can be at least one element from the group consisting of fluorine (F), chlorine (Cl), bromine (Br) and iodine (I).

[0132] The sulfide solid electrolyte can, for example, have a composition represented by the following general formula. Li 4-x M 1-x P x S4

[0133] In the formula, x can be greater than 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 0.9. x can also be less than 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, or 0.1. M can be at least one element selected from the group consisting of Al, Zn, In, Ge, Si, Sn, Sb, Ga, and Bi.

[0134] The sulfide solid electrolyte can, for example, have a composition represented by the following general formula. Li 10+x Ge 1+x P 2-x S 12

[0135] In the formula, x can be, for example, 0 or more, 0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, 0.5 or more, or 0.6 or more. For example, x can be 0.7 or less, 0.6 or less, 0.5 or less, 0.4 or less, 0.3 or less, 0.2 or less, or 0.1 or less. A sulfide solid electrolyte represented by the above general formula may, for example, comprise a crystalline phase of the LGPS type.

[0136] The solid halide electrolyte can, for example, have a composition represented by the following general formula. Li 6-na M a X6

[0137] In the formula, n represents the oxidation state of M. For example, M can contain an atom with an oxidation state of +3. For example, M can contain an atom with an oxidation state of +4. M can contain at least one element from the group consisting of Y, Al, Ti, Zr, Ca, and Mg. The relationship "0 < a < 2" can, for example, be satisfied. X can include at least one element from the group consisting of F, Cl, Br, and I.

[0138] The solid halide electrolyte can, for example, have a composition represented by the following general formula. Li 3-a Ti a Al 1-a F6

[0139] In the formula, 'a' can be, for example, 0 or more, 0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, 0.5 or more, 0.6 or more, 0.7 or more, 0.8 or more, or 0.9 or more. 'a' can also be, for example, 1 or less, 0.9 or less, 0.8 or less, 0.7 or less, 0.6 or less, 0.5 or less, 0.4 or less, 0.3 or less, 0.2 or less, or 0.1 or less.

[0140] The halide solid electrolyte can, for example, have a composition represented by the following general formula. Li3YCl a Br b I 6-a-b

[0141] The formula can, for example, satisfy the relationship "0≤(a+b)≤6". For example, a can be 0 or more, 1 or more, 2 or more, 3 or more, 4 or more, or 5 or more. b can be 0 or more, 1 or more, 2 or more, 3 or more, 2 or less, or 1 or less. b can be 6 or less, 5 or less, 4 or less, 3 or more, 2 or less, or 1 or less.

[0142] The oxide solid electrolyte can comprise at least one substance selected from the group consisting, for example, of LiNbO3, Li 1,5 Al 0,5 Ge 1,5 (PO4)3, La 2 / 3-x Li 3x TiO3 and Li7La3Zr2O 12The hydride solid electrolyte can, for example, comprise LiBH4 and / or the like. The nitride solid electrolyte can, for example, comprise Li3N, Li3BN2 and / or the like. [Examples]- Production of active material for the positive electrode -

[0143] Fig. The table below shows the experimental results. Active material for positive electrodes No. 1 to No. 6 was produced using the procedure described below. (a) Formation of a slurry

[0144] Lithium hydroxide monohydrate, manganese carbonate, iron phosphate, and lithium dihydrogen phosphate were produced in quantities corresponding to the composition formula “Li 1,1 Mn 0,7 Fe 0,3The composition ratios specified for PO4 were met. Glucose was added at a rate of 8% by mass relative to the raw material mixture. The resulting materials and water were mixed to form a slurry. The solids concentration of the slurry was 30% by mass. Wet milling was performed to achieve a D50 value of 0.30 µm. (b) Granulation

[0145] The slurry was spray-dried to form secondary particles. The target D50 value for the secondary particles was 9 ± 1 µm. The spray dryer had an air inlet temperature of 250 °C and an air outlet temperature of 115 ± 15 °C. The air inlet pressure was 2.0 MPa, and the nozzle pressure was X ± 0.1 MPa. The nozzle pressure "X" for each sample is shown in Fig. 8 shown. (c) Calcination

[0146] The secondary particles were calcined in an electric furnace in an inert atmosphere, thereby synthesizing LMFP. Fig. This shows the temperature profile during calcination. First, the furnace temperature is increased to 200 °C at a rate of 3 °C / minute. The furnace temperature is held at 200 °C for 1 hour. Then, the furnace temperature is increased to 650 °C at a rate of 5 °C / minute. The furnace temperature is held at 650 °C for 5 hours. Afterward, the furnace temperature is reduced to 400 °C at a rate of 2 °C / minute. Finally, the furnace temperature is reduced to room temperature at a rate of 15 °C / minute. - Evaluation -

[0147] A cylindrical lithium-ion secondary battery (a cylindrical cell) was manufactured. The cell configuration is described below. Power-generating element: wound Positive electrode: LMFP / AB / PAN=88 / 10 / 2 (in mass percent) Negative electrode: active material of the negative electrode (natural graphite), CMC, SBR Electrolyte: LiPF6 (1 mol / l), EC / DMC / EMC=3 / 4 / 3 (in volume)

[0148] The positive and negative electrodes were each produced by applying a slurry to the surface of a base material (a film layer). An Allgood film applicator (with a film thickness adjustment function) was used as the application device. After application of the slurry, the coating film was dried for 5 minutes at 80 °C.

[0149] A constant current (CC) discharge at 0.1 C was performed and the discharge capacity (Cp) was determined. 0,1). In addition, a constant current (CC) discharge at 1 C was performed and the discharge capacity (Cp1) was measured. "C" is a symbol that indicates the current. At a current of 1 C, the nominal capacity of a cell is charged or discharged in 1 hour. The discharge capacity (Cp1) was determined by the discharge capacity (Cp 0,1 The voltage is divided to calculate the discharge capacity ratio (1C / 0.1C). It can be assumed that the higher the discharge capacity ratio (1C / 0.1C), the better the performance and rate characteristics. - Results -

[0150] Referring to Fig. Rate properties tend to improve when the relationship “0.41 ≤ Sa / Ca ≤ 0.95” is satisfied. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2024-181994

[0001] WO 2020 / 065833

[0003]

Claims

[1] An active material of the positive electrode, comprising: secondary particle (2) Each of the secondary particles (2) comprises a primary particle (1), Each of the primary particles (1) comprises an olivine-type phosphate compound, Part of the surface of the secondary particle (2) has a depression (3), the surface of the secondary particle (2) is recessed at the depression (3) in the form of a concave surface and a cross-section of the secondary particle (2) satisfies the following relationship: 0.41≤Sa / Ca≤0.95 where Sa represents the area of ​​the cross-section of the secondary particle (2) and Ca represents the area of ​​a smallest circumcircle of the cross-section of the secondary particle (2). [2] Active material of the positive electrode according to claim 1, wherein the cross-section of the secondary particle (2) satisfies the following relationship: d / R≤1 where d represents the maximum depth of the depression (3) and R represents the radius of curvature of the depression (3). [3] Active material of the positive electrode according to claim 1, wherein the cross-section of the secondary particle (2) satisfies the following relationship: d / Sd≤0.5 where d represents a maximum depth of the depression (3) and Sd represents the diameter of the smallest circumcircle. [4] Active material of the positive electrode according to claim 1, wherein the cross-section of the secondary particle (2) satisfies the following relationships: D / Sd<1; and 1 <d / D where Sd represents a diameter of the smallest circumcircle, D represents an opening diameter of the recess (3) and d represents a maximum depth of the depression (3). [5] Active material of the positive electrode according to any one of claims 1 to 4, wherein the olivine-type phosphate compound comprises at least one compound selected from the group consisting of lithium manganese phosphate and lithium manganese iron phosphate. [6] Electrode, comprising: a positive electrode layer (11) the positive electrode layer (11) comprises the active material of the positive electrode according to any one of claims 1 to 4. [7] Battery comprising the electrode (10) according to claim 6. [8] Battery according to claim 7, which has a bipolar structure.

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