ACTIVE MATERIAL FOR POSITIVE ELECTRODES, ELECTRODE AND BATTERY

Abstract

An active material for a positive electrode comprises primary particles (1). Each of the primary particles (1) contains an olivine-type phosphate compound. In a TEM-EDS line analysis of a cross-section of the primary particle (1), performed along a radial direction of the primary particle (1), a phosphorus signal intensity line profile comprises a first region (1a) and a second region (1b). The first region (1a) is located at each end of the primary particle (1). The second region (1b) is located between the first regions (1a). The phosphorus signal intensity in the first region (1a) is lower than the phosphorus signal intensity in the second region (1b). The width of the first region (1a) is 0.5 to 20 nm.

Description

REFERENCE TO RELATED REGISTRATIONS

[0001] This non-provisional application is based on Japanese patent application No. 2024-183255, which was filed with the Japanese Patent Office on October 18, 2024, and the entire contents of which are hereby incorporated by reference. BACKGROUND area

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

[0003] International patent application no. WO 2016 / 158566 discloses lithium manganese phosphate nanoparticles with a characteristic crystal orientation. SUMMARY

[0004] Olivine-type phosphate compounds, such as lithium manganese phosphate, were investigated as active materials for the positive electrode. Olivine-type phosphate compounds tend to exhibit low specific capacitance. To date, investigations have been conducted to improve the specific capacitance, for example, by controlling the crystal orientation. However, there is still potential for improvement regarding the performance and output characteristics.

[0005] The purpose of this disclosure is to improve the performance and output characteristics.

[0006] The following describes the technical configuration and effects of the present disclosure. It should be noted that the mechanism of action according to the present disclosure contains assumptions. The mechanism of action does not limit the technical scope of the present disclosure.

[0007] 1. One aspect of the present disclosure is an active material for a positive electrode, or of the positive electrode. The active material for the positive electrode comprises primary particles. Each of the primary particles comprises an olivine-type phosphate compound. In the TEM-EDS line analysis of a cross-section of the primary particle, performed along a radial direction of the primary particle, a line profile of the signal intensity of phosphorus comprises a first region and a second region. The first region is located at each end of the primary particle. The second region is located between the first regions. The signal intensity of phosphorus in the first region is lower than the signal intensity of phosphorus in the second region. The width of the first region is 0.5 to 20 nm.

[0008] It is conceivable that the first region corresponds to the "outermost surface" of the primary particle. It is conceivable that the second region corresponds to the "main part" of the primary particle. At the time of line analysis using transmission electron microscopy-energy-dispersive X-ray spectroscopy (TEM-EDS), the signal intensity of phosphorus (P) corresponds to the P concentration at the measurement point. Based on the P concentration line profile, improved performance characteristics are expected when a region with a relatively low P concentration is present at the outermost surface of the primary particle and the width of this region is between 5 and 20 nm.

[0009] 2. The active material of the positive electrode according to point “1” above may, for example, have the following configuration. The active material of the positive electrode comprises secondary particles. The secondary particles comprise the primary particles. In TEM-EDS line analysis of a cross-section of the secondary particle, performed along a radial direction of the secondary particle, a line profile of signal intensity of phosphorus repeatedly rises and falls.

[0010] If the primary particles within the secondary particle are arranged such that the signal intensity line profile of P repeatedly rises and falls, an improvement in performance characteristics can be expected. It is conceivable that a trough in the line profile for a secondary particle corresponds to a first region of a primary particle. It is conceivable that the width of the first region correlates with the degree of constriction between the primary particles. It is conceivable that as the constriction progresses, the width of the first region (the region of low concentration) decreases. If the constriction progresses excessively, the distance that ions and electrons must travel becomes longer, which can lead to a deterioration in performance characteristics.Conversely, if the width of the first region (the low-concentration region) becomes too large, the particle-to-particle conduction network becomes sparse, which can also lead to a deterioration of performance characteristics. It is conceivable that if the width of the first region (the low-concentration region) on the line profile lies between 5 and 20 nm, a preferred conduction distance can be achieved and a preferred network can be formed.

[0011] 3. The active material of the positive electrode according to point “2” above may, for example, have the following configuration. On the signal intensity line profile of phosphorus, the mean distance between the valleys is 11 to 290 nm.

[0012] If the mean distance between the valleys (the mean distance between the valleys) is 11 to 290 nm, a further improvement in performance characteristics can be expected.

[0013] 4. The active material of the positive electrode according to point “2” or “3” above may, for example, have the following configuration. On the line profile, the ratio of the lowest value of the signal intensity of phosphorus to the highest value of the signal intensity of phosphorus is 0.90 or less.

[0014] The ratio of the lowest to the highest signal intensity of phosphorus can also be referred to as the "peak-to-valley ratio". A peak-to-valley ratio of 0.90 or less indicates further improvement in performance characteristics.

[0015] 5. The active material of the positive electrode according to point “4” above may, for example, have the following configuration. The ratio of the lowest value to the highest value is 0.69 or less.

[0016] If the peak-to-trough ratio is 0.69 or less, a further improvement in the initial characteristics can be expected.

[0017] 6. The active material of the positive electrode according to point “5” above may, for example, have the following configuration. The ratio of the lowest value to the highest value is 0.48 or less.

[0018] If the peak-to-trough ratio is 0.48 or less, a further improvement in performance characteristics can be expected.

[0019] 7. The active material for the positive electrode according to one of the preceding points “1” to “6” may, for example, have the following configuration.

[0020] The olivine-type phosphate compound comprises at least one compound selected from the group consisting of lithium iron phosphate (LFP), lithium manganese phosphate (LMP) and lithium manganese iron phosphate (LMFP).

[0021] 8. One aspect of the present disclosure is an electrode. The electrode comprises a positive electrode layer. The positive electrode layer comprises the active material for the positive electrode according to any one of the preceding points “1” to “7”.

[0022] The positive electrode layer can also be referred to as the "active material layer of the positive electrode," the "composite material layer of the positive electrode," or similar terms. The "electrode" can be either a "monopolar electrode (positive electrode)" or a "bipolar electrode," as long as it includes a positive electrode layer.

[0023] 9. One aspect of the present disclosure is a battery. The battery comprises the electrode according to the preceding point “8”.

[0024] 10. The battery according to point “9” above may, for example, have the following configuration. The battery has a bipolar structure.

[0025] The bipolar structure can be formed by stacking bipolar electrodes. An improvement in performance characteristics can be expected with a bipolar structure.

[0026] The following describes an embodiment of the present disclosure (hereinafter referred to simply as "the present embodiment") and an example of the present disclosure (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 disclosure. 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 disclosure 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.

[0027] The foregoing and other objectives, features, aspects and advantages of the present disclosure will become more apparent from the following detailed description of the present disclosure in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a conceptual view illustrating the TEM-EDS line analysis of a primary particle. Fig. Figure 2 is a conceptual view illustrating the TEM-EDS line analysis of a secondary particle. Fig. Figure 3 is a conceptual view illustrating an active material for a positive electrode according to the present embodiment. Fig. Figure 4 is a schematic flowchart illustrating a method for producing an active material for a positive electrode according to the present embodiment. Fig. Figure 5 is a schematic perspective view illustrating a battery according to the present embodiment. Fig. Figure 6 is a schematic view of a cross-section along line VI-VI in Fig. 5. Fig. 7 is a temperature profile during calcination. Fig. Figure 8 is a table showing the test results. DESCRIPTION OF PREFERRED FORMS - Terms and expressions -

[0028] 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.

[0029] Expressions like "can" and "could" do not mean "must" (obligation), but rather "there is a possibility" (tolerance).

[0030] With regard to the numerous steps, operations, processes, and the like contained 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.

[0031] Expressions like "first" and "second" are used solely to distinguish between a multitude of elements. Such expressions do not restrict the scope of these elements. For example, these expressions are independent of the order and meaning of these elements.

[0032] 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 achieved, the relative direction, angle, distance, and the like may vary. All geometric terms in this description may involve tolerances and / or errors related to design, operation, production, and / or the like. The dimensional relationships shown in the illustrations do not necessarily reflect the actual dimensional relationships. To facilitate understanding for the reader, the dimensional relationships in the illustrations may have been altered. For example, length, width, thickness, and the like may have been changed. A part of a particular configuration may have been omitted.

[0033] A singular form can also encompass its plural meaning unless otherwise specified. For example, a particle can mean a multitude of particles, a group of particles, and a powdery and granular material. "A multitude of particles" can also be referred to as a "group of particles."

[0034] 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.

[0035] All numerical values ​​are considered modified by the term "approximately." The term "approximately" may mean, for example, ±5%, ±3%, ±1%, and / or similar. 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 value 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 value. 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.

[0036] A device, software, and / or similar item 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 item presented as an example. If a similar product is used, the measurement conditions can be adjusted to suit the device.

[0037] TEM-EDS line analysis of a primary and secondary particle is performed according to the procedure described below. A positive electrode active material (powder) is embedded in resin to prepare a sample. The sample is sectioned using a focused ion beam (FIB) or a cross-sectional polisher (CP). The sample is then examined using TEM. To simplify the measurement, a relatively large secondary particle can be selected. For example, a secondary particle with a maximum Feret diameter of 10 µm or more can be chosen for EDS line analysis of a primary and secondary particle.

[0038] The magnification for the examination can be, for example, approximately 10,000x to 50,000x. In the case of a secondary particle of approximately 10 µm, the magnification for the examination can be, for example, approximately 10,000x. In this case, a TEM image can be obtained that covers the area from the center of the secondary particle to its outermost edge. The magnification for the examination of a primary particle can be, for example, approximately 20,000x.

[0039] Fig. Figure 1 is a conceptual representation illustrating the TEM-EDS line analysis of a primary particle. In a cross-sectional TEM image, a least circle is fitted to the contour of a primary particle 1. The radial direction of the least circle is considered to be the radial direction of the primary particle. The TEM-EDS line analysis is performed along the radial direction of the primary particle, yielding a line profile of the signal intensity P. The TEM-EDS line analysis is performed along a path that intersects the primary particle radially. At each end of the primary particle, a relatively low signal intensity can be observed for a region of a certain size. For example, the region with a signal intensity of up to 105% relative to the lowest value of the signal intensity is considered the first region 1a.Between the first region 1a and the second region 1b, a relatively high signal intensity can be observed for a region of a certain size. For example, the region with a signal intensity of up to 95% relative to the highest value of the signal intensity is considered the second region 1b. The arithmetic mean of the width "X1" of the first region 1a at one end and the width "X2" of the first region 1a at the other end is considered the width "X" of the first region 1a.

[0040] Fig. Figure 2 is a conceptual representation illustrating the TEM-EDS line analysis of a secondary particle. In a TEM cross-sectional image, a least circle is fitted to the contour of a secondary particle 2. The radial direction of the least circle is considered to be the radial direction of the secondary particle. The TEM-EDS analysis is performed along the radial direction of the secondary particle, yielding a line profile of signal intensity P. The TEM-EDS analysis can be performed, for example, for a region covering 1 / 4 or more (or 1 / 2 or more) of the diameter of the least circle. For example, the TEM-EDS analysis can be performed for a region extending from the center or near the center of the secondary particle 2 to the outermost edge of the secondary particle. For example, the TEM-EDS analysis can be performed in a direction that intersects the secondary particle 2.The line profile can rise and fall. The arithmetic mean of the distances between the valleys for a group of 5 or more adjacent valleys is considered the mean distance "Y".

[0041] For a group of 5 or more adjacent valleys, the lowest value is "Z". 2 min “The signal intensity is calculated. For a group of 5 or more adjacent peaks, the highest value “Z” is used. 2 max “The signal intensity is calculated. The lowest value is divided by the highest value, thus calculating the peak-to-trough ratio “Z”.

[0042] The "maximum Feret diameter" refers to the length of the long side of the smallest circumscribing rectangle (either oblong or square) that encloses the particle. If the smallest circumscribing rectangle is square, the length of the long side refers to the length of one side.

[0043] "D50" refers to a particle size in the volume-based particle size distribution (cumulative distribution) where the cumulative value reaches 50%. The volume-based particle size distribution is measured using a laser diffraction particle size distribution analyzer.

[0044] The chemical composition of a compound can be measured using inductively coupled plasma atomic emission spectroscopy (ICP-AES). A sample (e.g., an active material from a 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.

[0045] 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 molar ratio (Al / O) is "2 / 3". "Al₂O₃" represents a compound containing Al and O in any molar ratio, 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.

[0046] "Derivative" refers to a compound derived from its original compound by at least one partial modification selected from the group consisting of the introduction of a functional group, the substitution of atoms, oxidation, reduction, and other chemical reactions. The position of the modification can be one or more positions. For example, a "substituent" can include at least one 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, 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 variety of substituents can be linked together to form a ring. - Active material of the positive electrode -

[0047] Fig. Figure 3 is a conceptual representation illustrating an active material of the positive electrode according to the present embodiment. The active material of the positive electrode comprises primary particles 1. "Primary particle" is the smallest constituent unit of a particle. The maximum Feret diameter of the primary particle 1 can be, for example, 1 nm or more, 5 nm or more, 10 nm or more, 15 nm or more, 20 nm or more, 25 nm or more, 50 nm or more, 75 nm or more, 100 nm or more, 150 nm or more, 200 nm or more, 250 nm or more, 300 nm or more, 350 nm or more, 400 nm or more, or 450 nm or more.The maximum Feret diameter of primary particle 1 can be, for example, 1 µm or less, or 500 nm or less, or 450 nm or less, or 400 nm or less, or 350 nm or less, or 300 nm or less, or 250 nm or less, or 200 nm or less, or 150 nm or less, or 100 nm or less, or 75 nm or less, or 50 nm or less, or 25 nm or less, or 20 nm or less, or 15 nm or less, or 10 nm or less, or 5 nm or less. The maximum Feret diameter of primary particle 1 is the arithmetic mean of 30 primary particles 1. Primary particle 1 can have any shape. For example, primary particle 1 can be spherical, rod-shaped, prismatic, and / or the like.

[0048] The primary particle 1 contains a phosphoric acid (PO4) backbone. At the outermost surface of the primary particle 1, the local phosphorus concentration is relatively low. In other words, in a TEM-EDS line analysis performed along the radial direction of the primary particle, the signal intensity line profile of phosphorus comprises a first region 1a and a second region 1b. The signal intensity of phosphorus in the first region 1a is lower than the signal intensity of phosphorus in the second region 1b. The ratio of the lowest value “Z 1 min “ the signal intensity in the first area 1a to the highest value “Z 1 max “ the signal intensity in the second area 1b, namely “Z 1 min / Z 1 max “, is less than 1. The ratio “Z 1 min / Z 1 max“For example, it can be 0.90 or less, 0.80 or less, 0.70 or less, 0.60 or less, 0.50 or less, 0.40 or less, 0.30 or less, 0.20 or less, or 0.10 or less. The ratio “Z1 / Z2” can be greater than 0 or 0.10 or greater than 0.20 or greater than 0.30 or greater than 0.40 or greater than 0.50 or greater than 0.60 or greater than 0.70 or greater than 0.80.

[0049] The first region 1a is located at each end of the primary particle 1. The second region 1b is located between the first regions 1a. Therefore, it is conceivable that in a cross-section of the primary particle 1, the second region 1b is surrounded by the first region 1a.

[0050] The width “X” of the first region 1a is 0.5 to 20 nm. The width “X” can be, for example, 1 nm or more, 2.5 nm or more, 5 nm or more, 7.5 nm or more, 10 nm or more, 12.5 nm or more, 15 nm or more, or 17.5 nm or more. The width “X” can also be, for example, 17.5 nm or less, 15 nm or less, 12.5 nm or less, 10 nm or less, 7.5 nm or less, 5 nm or less, 2.5 nm or less, or 1 nm or less.

[0051] The width of the second region 1b can, for example, be greater than the width “X” of the first region 1a. The width of the second region 1b can, for example, be 1 nm or more, 5 nm or more, 10 nm or more, 15 nm or more, 20 nm or more, 25 nm or more, 50 nm or more, 75 nm or more, 100 nm or more, 150 nm or more, 200 nm or more, 250 nm or more, 300 nm or more, 350 nm or more, 400 nm or more, or 450 nm or more. The width of the second region 1b may, for example, be 500 nm or less, or 450 nm or less, or 400 nm or less, or 350 nm or less, or 300 nm or less, or 250 nm or less, or 200 nm or less, or 150 nm or less, or 100 nm or less, or 75 nm or less, or 50 nm or less, or 25 nm or less, or 20 nm or less, or 15 nm or less, or 10 nm or less, or 5 nm or less.

[0052] Primary particles 1 can exist in isolation. Isolated primary particles 1 are also referred to as "single particles". Primary particles 1 can form a secondary particle 2. That is, the active material of the positive electrode can contain secondary particles 2. Secondary particles 2 are an aggregate of primary particles 1. Secondary particles 2 contain a multitude of primary particles 1. The number of primary particles 1 contained in a secondary particle 2 can be, for example, 2 or more, 5 or more, 10 or more, 50 or more, 100 or more, 500 or more, or 1000 or more. The number of primary particles 1 contained in a secondary particle 2 can be, for example, 5000 or less, 1000 or less, 500 or less, 100 or less, 50 or less, 10 or less, or 5 or less.

[0053] The active material of the positive electrode can contain a group (powder) of secondary particles 2. The D50 value of the powder can be, for example, 5 µm or more, 10 µm or more, 15 µm or more, or 20 µm or more. Alternatively, the D50 value 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.

[0054] The secondary particle 2 can have any shape. For example, the secondary particle 2 can be spherical, rod-shaped, prismatic, and / or the like. If the secondary particle 2 is spherical, for example, the packing properties and the like are expected to be improved. The sphericity of the secondary particle 2 can be, for example, 0.85 or more, 0.90 or more, or 0.95 or more. "Sphericity" refers to the circularity in a TEM image (a two-dimensional image). The sphericity (circularity) is determined by the following equation. ψ=4πS / L2 ψ: Sphericity (roundness) π: Circular constant S: Cross-sectional area of ​​the secondary particle 2 (the area of ​​a region surrounded by the contour of the secondary particle 2) L: Circumference of secondary particle 2 (the length of the contour of secondary particle 2)

[0055] The sphericity refers to the arithmetic mean of 30 secondary particles.

[0056] In the TEM-EDS line analysis of a cross-section of secondary particle 2, performed along the radial direction of the secondary particle, the resulting line profile of the signal intensity P can repeatedly rise and fall. The number of repetitions of the rise and fall can be, for example, 2 or more, 5 or more, 10 or more, 20 or more, 50 or more, 100 or more, or 200 or more. Alternatively, the number of repetitions can be, for example, 500 or less, 200 or less, 100 or less, 50 or less, 20 or less, 10 or less, or 5 or less.

[0057] The repetition of the rise and fall of the line profile can be either periodic or non-periodic. The mean distance between the troughs "Y" can be, for example, 5 nm or more, 10 nm or more, 15 nm or more, 20 nm or more, 25 nm or more, 50 nm or more, 75 nm or more, 100 nm or more, 125 nm or more, 150 nm or more, 175 nm or more, 200 nm or more, 225 nm or more, 250 nm or more, 275 nm or more, 300 nm or more, 325 nm or more, 350 nm or more, or 400 nm or more.The mean distance "Y" between the valleys can be, for example, 500 nm or less, or 450 nm or less, or 400 nm or less, or 350 nm or less, or 325 nm or less, or 300 nm or less, or 275 nm or less, or 250 nm or less, or 225 nm or less, or 200 nm or less, or 175 nm or less, or 150 nm or less, or 125 nm or less, or 100 nm or less, or 75 nm or less, or 50 nm or less, or 25 nm or less, or 20 nm or less, or 15 nm or less. The mean distance between the valleys "Y" can, for example, be between 11 and 290 nm.

[0058] The peak-to-trough ratio "Z" of the line profile can be, for example, 0.93 or less, 0.90 or less, 0.69 or less, 0.48 or less, 0.40 or less, 0.30 or less, 0.22 or less, or 0.10 or less. The peak-to-trough ratio "Z" can be, for example, greater than 0, or 0.10 or greater, or 0.20 or greater, or 0.30 or greater, or 0.40 or greater, or 0.50 or greater, or 0.60 or greater, or 0.70 or greater, or 0.80 or greater.

[0059] Primary particle 1 contains an olivine-type phosphate compound. "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. Primary particle 1 may, for example, be a single-phase compound. As long as it contains an olivine-type crystalline phase, primary particle 1 may also contain a phase belonging to a different space group. Primary particle 1 may also contain, for example, an amorphous phase and / or the like.

[0060] The olivine-type phosphate compound can, for example, contain at least one compound from the group consisting of LFP, LMP, and LMFP. The olivine-type phosphate compound can, for example, have a composition represented by the following general formula. Li a Mn 1-x Fe x PO4

[0061] The relationship "0.5 ≤ a ≤ 1.5" can be satisfied, for example. "x" can be, for example, 0 or more, 0.05 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. "x" 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.

[0062] The olivine-type phosphate compound can be doped with an element (a dopant) that is not lithium (Li), manganese (Mn), iron (Fe), phosphorus (P), or oxygen (O). The amount of doping (the proportion of the amount of substance relative to the amount of Li) can, for example, range between 0.01 and 0.1.The doping agent may comprise at least one substance from the group consisting of 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.

[0063] The active material of the positive electrode may further contain an additional component, provided it contains an olivine-type phosphate compound. This additional component may, for example, be 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 be, for example, 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.

[0064] The LNO can, for example, have a crystal structure belonging to the space group R-3m. The LNO can, for example, have a composition represented by the following general formula. Li 1-a Ni x M 1-x O2

[0065] The formula satisfies the relationships -0.5 ≤ a ≤ 0.5, 0 ≤ x ≤ 1. For example, M can contain 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 oder 0,9 ≤ x ≤ 1 erfüllt sein. Beispielsweise kann die Beziehung - 0,4 ≤ a ≤ 0,4, -0,3 ≤ a ≤ 0,3, -0,2≤a≤0,2 oder -0,1≤a≤0,1 erfüllt sein.

[0066] The LNO can be at least one of the group consisting of LiNi 0,9 Co 0,1 02, LiNi 0,9 Mn 0,1 Contains O2 and LiNiO2.

[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 "NCM". Li 1-a Ni x CO y Mn z O2

[0068] The formula satisfies the relationships -0.5 ≤ a ≤ 0.5, 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.

[0069] 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.

[0070] 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 1-a Ni x CO y Al z O2

[0071] The formula contains the relationships -0.5≤a≤0.5, 0 <x<1, 0<y<1, 0<z<1, x+y+z=1 erfüllt. Beispielsweise kann die Beziehung 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.

[0072] NCA can 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.

[0073] Carbon can adhere to at least part of the surface of the primary particle 1. The carbon can form a carbon layer 3. The amount of adhering carbon by mass fraction relative to the primary particle 1 (an olivine-type phosphate compound) can 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 relative to the primary particle 1 can be, for example, 5% or less, 4% or less, or 3% or less. - Method for producing an active material for a positive electrode -

[0074] Fig. Figure 4 is a schematic flowchart illustrating a process for producing an active material for a positive electrode according to the present embodiment. Hereinafter, the “process for producing an active material for a positive electrode according to the present embodiment” may simply be referred to as “the present process”. The present process may, for example, include “(a) forming a slurry”, “(b) granulating”, “(c) calcining”, and the like. (a) Formation of a slurry

[0075] The present method may, for example, involve the formation of a slurry by mixing a lithium compound, a manganese compound, an iron compound, a phosphate compound, a carbon source, and a solvent. For example, the lithium compound, the manganese compound, the iron compound, and the phosphate compound may be prepared in quantities corresponding to the composition formula “Li a Mn 1-x Fe x The 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 phosphate compound may, for example, comprise lithium dihydrogen phosphate and / or the like. The iron compound may, for example, comprise iron phosphate and / or the like.

[0076] The carbon source is a carbon-based raw material intended to adhere to the surface of the primary particles. The carbon source can include, for example, sugars, organic acids, and / or similar substances. Examples include glucose, sucrose, fructose, citric acid, and / or similar materials. The amount of carbon source to be added, in mass fraction relative to the raw material mixture, can range from 1% to 20%.

[0077] 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%.

[0078] Wet milling can be performed to adjust the particle size in the slurry. For example, wet milling can be performed to achieve a D50 value of 0.10 to 1 µm. The degree of wet milling can also be adjusted to modify the mean valley-to-valley distance "Y". (b) Granulation

[0079] The present process can, for example, include granulation, namely the drying of the slurry to produce secondary particles (precursors). For instance, spray drying can be used for granulation to produce secondary particles. Secondary particles formed by the granulation process are also referred to as "granules." That is, the secondary particles can also be described as granules. (c) Calcination

[0080] The present process can include carrying out heat treatment of the secondary particles (precursors) to produce an olivine-type phosphate compound. Any heat treatment furnace (such as an electric furnace, a muffle furnace, and / or the like) can be used. In the present process, calcination is carried out under conditions in which no narrowing occurs between primary particles. The heat treatment atmosphere can, for example, be an inert atmosphere.

[0081] The inert atmosphere can be, for example, 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. For example, the calcination conditions can be selected to adjust the width "X" of the first region. For example, temporarily halting the temperature increase process at or near 200 °C during the calcination process and maintaining the temperature (200 °C) for approximately 1 hour, instead of continuously increasing the temperature, can tend to prevent necking or pull-in. - Liquid-filled battery -

[0082] In some of the present embodiments, the battery can be a liquid-filled battery. "Liquid-filled battery" refers to a battery that contains an electrolyte solution. For example, a polymer battery contains an electrolyte solution and is therefore a liquid-filled 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.

[0083] Fig. Figure 5 is a schematic perspective view illustrating a battery according to the present embodiment. Fig. Figure 6 is a schematic view of a cross-section along line VI-VI in Fig. 5. In the following, “perpendicular to the plane” refers to the direction of a normal to the surface of a sheet-shaped element (such as a film or an electrode). “In the plane” refers to any direction orthogonal to the direction perpendicular to the plane. In the drawings of the present embodiment, the Z-axis direction corresponds to the direction perpendicular to the plane.

[0084] The X-axis direction and the Y-axis direction are each examples of a direction in the plane.

[0085] A battery 100 comprises an outer casing 90 and a power generating element 50. The outer casing 90 houses the power generating element 50. The outer casing 90 may, for example, comprise a first power collecting plate 91, a first laminated film 92, a second laminated film 93, and a second power collecting plate 94. The first laminated film 92 and the second laminated film 93 are joined at one end in one direction within the plane. At the joint between the first laminated film 92 and the second laminated film 93, a sealing material (not shown) may be arranged between the first laminated film 92 and the second laminated film 93.

[0086] 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 at the connection point.

[0087] The current-generating element 50 comprises a plurality of bipolar electrodes 10. The bipolar electrodes 10 are stacked in the direction perpendicular to the plane (the Z-axis direction). In the direction perpendicular to the plane, each bipolar electrode 10 comprises, in this order, a positive electrode layer 11, a current-collecting foil layer 13, and a negative electrode layer 12. In a 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.

[0088] For example, the current-collecting foil layer 13 can extend in one direction within the plane over the entire periphery beyond the positive electrode layer 11 and the negative electrode layer 12.

[0089] The current-collecting foil layer 13 is a conductor. For example, the current-collecting foil layer 13 can comprise a metal foil, an electrically conductive resin layer, and / or the like. For example, the current-collecting foil layer 13 can be formed by combining an aluminum foil layer and a copper foil layer. 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.

[0090] 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. For example, the sealing material 30 can 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 spaces between the current-collecting foil layers 13 that are adjacent to each other in a perpendicular direction. The spaces 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

[0091] The positive electrode layer 11 is attached 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 an active material of the positive electrode. That is, the battery 100 comprises an active material of the positive electrode. The details of the active material of the positive electrode are as described above.

[0092] 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. For example, 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).

[0093] The amount of binder to be used can, for example, be between 0.1 and 10 parts by mass, based on 100 parts by mass of the active material of the positive electrode. The binder can contain 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.

[0094] 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 allyl phenyl ether phosphate, zeolite, silane coupling agents, MoS₂, WO₃, and / or the like. Negative electrode layer

[0095] The negative electrode layer 12 is attached to one side of the current-collecting foil layer 13. The negative electrode layer 12 is positioned on the opposite side from 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 contains an active material of the negative electrode.

[0096] 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.

[0097] The active material of the negative electrode can contain any components. The active material of the negative electrode can contain at least one component selected from the group consisting 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.

[0098] 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 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" or "(natural graphite) / (synthetic graphite) = 2 / 8 to 8 / 2" or "(natural graphite) / (synthetic graphite) = 3 / 7 to 7 / 3".

[0099] 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 contain at least one element from the group consisting of P, W, Al, and O. The other material can, for example, include at least one element from the group consisting of Al(OH)3, AlOOH, Al2O3, WO3, Li2CO3, LiHCO3, and Li3PO4.

[0100] The alloy-based active material can, for example, include at least one from the group consisting of Si, Li silicate, SiO, a Si-based alloy, tin (Sn), SnO and an Sn-based alloy.

[0101] SiO can be represented, for example, by the following general formula. SiOx

[0102] 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.

[0103] "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

[0104] 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.

[0105] 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 in the form of a continuous network. Gaps in the resin framework form pores. The resin film allows an electrolyte solution to permeate it. The resin film can, for example, have a mean pore size of 1 µm or less. The resin film can, for example, 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.

[0106] The resin film may contain at least one substance selected from the group consisting 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 contain at least one substance from the group consisting of polyethylene (PE), polypropylene (PP), polyamide (PA), polyamide-imide (PAI), polyimide (PL), 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, for example, have a thickness of 5 to 50 µm or 10 to 25 µm.

[0107] 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 formed from PE. The PE layer can have a switching function. The plastic film can, for example, have a multi-layer structure. The plastic film can, for example, comprise a PP layer and a PE layer. The framework of a PP layer consists of PP. The plastic film can, for example, have a three-layer structure. The resin film can, for example, be formed 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.

[0108] The inorganic particle layer can be formed on the surface of the resin film. The inorganic particle layer can be formed on only one side of the resin film or on both sides. The inorganic particle layer can be formed 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.

[0109] The inorganic particle layer is porous. The inorganic particle layer contains 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, contain a heat-resistant material. The inorganic particle layer containing a heat-resistant material is also referred to as an "HRL (Heat Resistance Layer)." The inorganic particles can include at least one material 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 have, for example, a D50 of 0.1 to 10 µm or of 0.5 to 3 µm. The inorganic particle layer can further contain a binder. The binder can be 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.

[0110] Separator 20 can, for example, contain an organic particle layer. Separator 20 can, for example, contain an organic particle layer instead of a resin layer. Separator 20 can, for example, contain an organic particle layer instead of an inorganic particle layer. Separator 20 can contain both the resin film and an organic particle layer. Separator 20 can contain both the inorganic particle layer and an organic particle layer. Separator 20 can contain the resin film, the inorganic particle layer, and an organic particle layer.

[0111] 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 contains organic particles. These organic particles can also be referred to as "organic filler." The organic particles may contain a heat-resistant material. The organic particles may contain at least one material from the group consisting of PE, PP, PTFE, PI, PAI, PA, aramid, and the like. The organic particles may be, for example, spherical, rod-shaped, plate-shaped, fibrous, and / or the like. The organic particles may, for example, have a D50 value of 0.1 to 10 µm or 0.5 to 3 µm.

[0112] Separator 20 can, for example, include a mixed layer. The mixed layer includes both inorganic and organic particles. electrolyte solution

[0113] The electrolyte solution is a liquid electrolyte. It comprises 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 contains a carrier salt (a lithium salt). The solute can be, for example, an inorganic acid salt, an imide salt, an oxalate complex, a halide, and / or the like. The solute may, for example, contain 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.

[0114] The electrolyte solution may, for example, contain a carbonate-based solvent (a carbonate ester-based solvent). The solvent may, for example, contain 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.

[0115] The solvent can contain 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".

[0116] The solvent may contain 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) may 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".

[0117] The solvent may contain, for example, EC, FEC, EMC, DMC, and DEC. The volume ratio of these components may, for example, satisfy the relationship represented by the following equation. VEC+VFEC+VEMC+VDMC+VDEC=10

[0118] In the equation above, V EC , V FEC , V EMC , V DMC and V DECeach for the volume ratio of EC, FEC, EMC, DMC and DEC.

[0119] 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.

[0120] For example, the relationship 1 ≤ V EC ≤ 2 or 2 ≤ V EC ≤ 3 must be fulfilled.

[0121] For example, the relationship 1 ≤ V FEC ≤ 2 or 2 ≤ V FEC ≤ 4 must be fulfilled.

[0122] For example, the relationship 3 ≤ V EMC ≤ 4 or 6 ≤ V EMC ≤ 8 must be fulfilled.

[0123] For example, the relationship 3 ≤ V DMC ≤ 4 or 6 ≤ V DMC ≤ 8 must be fulfilled.

[0124] For example, the relationship 3 ≤ V DEC ≤ 4 or 6 ≤ V DEC ≤ 8 must be fulfilled.

[0125] 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=112 / 4 / 3”, “EC / FEC / DMC / EMC=2 / 1 / 3 / 4”, “EC / FEC / DMC / EMC=1 / 2 / 3 / 4” (volume ratio) and / or the like.

[0126] 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.

[0127] The electrolyte solution may contain any additives. The amount to be added (the mass fraction of the total electrolyte solution) may be, for example, 0.01 to 5%, or 0.05 to 3%, or 0.1 to 1%. The additive may include, for example, a solid electrolyte interphase (SEI) formation promoter, a salt formation inhibitor, a gas-forming agent, a charge inhibitor, a flame retardant, an antioxidant, an electrode protectant, a surfactant, and / or the like.

[0128] The additive may comprise at least one substance selected 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) and 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 and 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 and Octafluorotoluene), Benzotrifluoride (such as Benzotrifluoride,2-Fluorobenzotrifluoride, 3-Fluorobenzotrifluoride, 4-Fluorobenzotrifluoride, 2-Methylbenzotrifluoride, 3-Methylbenzotrifluoride and 4-Methylbenzotrifluoride), fluoroxylene (such as 3-fluoro-o-xylene, 4-fluoro-o-xylene, 2-fluoro-m-xylene and 5-fluoro-m-xylene), sulfur-containing heterocyclic compounds (such as benzothiazole, 2-methylbenzothiazole and tetrathiafulvalene), nitrile compounds (such as adiponitrile and succinonitrile), phosphates (such as trimethyl phosphate and triethyl phosphate), carboxylic anhydrides (such as acetic anhydride, propionic anhydride, oxalic anhydride, succinic anhydride, maleic anhydride, phthalic anhydride and benzoic anhydride) and derivatives thereof.

[0129] 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. Conversely, a component described above as an additive can be used as both a solute and a solvent.

[0130] The electrolyte solution may contain an ionic liquid. The ionic liquid may, for example, contain at least one substance selected from the group consisting 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.

[0131] In some embodiments, the battery may contain a gelled electrolyte. In other words, the battery may be a polymer battery. The gelled electrolyte may contain an electrolyte solution and a polymer material. The polymer material may form a polymer matrix. The polymer material may comprise at least one of the following: PVdF, PVdF-HFP, polyacrylonitrile (PAN), PVdF-PAN, polyethylene oxide (PEO), polyethylene glycol (PEG), and derivatives thereof. - Solid-state battery -

[0132] In some embodiments, the battery can be a solid-state battery. The solid-state battery can have a bipolar structure. The solid-state battery contains a solid electrolyte instead of the electrolyte solution and 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 contains, for example, a solid electrolyte and a binder.

[0133] 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 of the solid electrolyte can be, for example, 5 µm or less, 4 µm or less, 3 µm or less, 2 µm or less, or 1 µm or less.

[0134] The solid electrolyte may contain at least one solid electrolyte selected 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.

[0135] 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 contain any other components.

[0136] The sulfide solid electrolyte can 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.

[0137] For example, "Lil-LiBr-Li3PS4" refers to a sulfide solid electrolyte produced by mixing Lil, LiBr, and Li3PS4 in a freely selectable ratio by amount of substance. 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 (by amount of substance)."

[0138] The sulfide solid electrolyte can, for example, have a composition represented by the following general formula. xLi2S-(1-x)P2S5

[0139] 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. If, for example, x is 0.75, "XLi2S-(1-x)P2S5" can have a composition of Li3PS4.

[0140] The sulfide solid electrolyte can, for example, have a composition represented by the following general formula. yLil−zLiBr−(100−y−z)[xLi2S−(1−x)P2S5]

[0141] 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.

[0142] 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

[0143] The formula satisfies the relationships "0<(7-x-2y)", "0<(6-xy)", "0≤x" and "0≤y". X can contain at least one element from the group consisting of fluorine (F), chlorine (Cl), bromine (Br) and iodine (I).

[0144] 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

[0145] 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 contain at least one element from the group consisting of Al, Zn, In, Ge, Si, Sn, Sb, Ga, and Bi.

[0146] 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

[0147] 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 general formula above may, for example, contain a crystalline phase of the LGPS type.

[0148] The solid halide electrolyte can, for example, have a composition represented by the following general formula. Li 6-na M a X6

[0149] 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 contain at least one element from the group consisting of F, Cl, Br, and I.

[0150] 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

[0151] 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. For example, a can be 1 or less, or 0.9 or less, or 0.8 or less, or 0.7 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.

[0152] The halide solid electrolyte can, for example, have a composition represented by the following general formula. Li3YCl a Br b I 6-a-b

[0153] 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.

[0154] The oxide solid electrolyte can, for example, contain at least one substance selected from the group consisting 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 may contain, for example, LiBH4 and / or the like. The nitride solid electrolyte may contain, for example, Li3N, Li3BN2 and / or the like. [Examples]- Production of active material for the positive electrode -

[0155] Various active materials for the positive electrode were produced using the method described below. (a) Formation of a slurry

[0156] Various active materials for the positive electrode were prepared according to the following procedure. Lithium hydroxide monohydrate, manganese carbonate, iron phosphate, and lithium dihydrogen phosphate were produced in quantities corresponding to the composition formula “Li 1,04 Mn 0,5 Fe 0,4The composition ratios specified for PO4 were met. Glucose was produced at a rate of 8% by mass, based on the total mass of the raw materials. The materials thus produced were mixed with water to form a slurry. The solids concentration of the slurry was 30% by mass. Wet milling was carried out to achieve a D50 value of 0.30 µm. (b) Granulation

[0157] The slurry was spray-dried to form secondary particles. The basic settings of the spray dryer are as follows. Air inlet temperature: 250 °C Temperature at the air outlet: 115 ± 15 °C Air intake pressure: 2.0 MPa Spray nozzle pressure: 0.2 ± 0.1 MPa Target value for D50 of secondary particles: 9 ± 1 µm (c) Calcination

[0158] The secondary particles were calcined in a nitrogen 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 decreased to 400 °C at a rate of 2 °C / minute. Finally, the furnace temperature is cooled to room temperature at a rate of 15 °C / minute.

[0159] Fig. The table below contains the experimental results. Various conditions of the procedure described above (such as the degree of wet milling of the slurry, the time to maintain the temperature during calcination, the temperature increase rate, the temperature decrease rate, and / or the amount of carbon source added) were modified to produce active materials for positive electrodes No. 1 to No. 17. - Evaluation - Manufacturing a button cell

[0160] The active material of the positive electrode, a conductive material (acetylene carbon black), and a binder (PVdF) were mixed together to form a mixture. The mixing ratio (by mass) was 92 / 5 / 3: (active material of the positive electrode) / (conductive material) / binder. The mixture was dispersed in a solvent (N-methyl-2-pyrrolidone) to form a paste. The solids concentration of the paste was 50% by mass. The paste was applied to the surface of an aluminum foil and subsequently dried, forming a positive electrode layer. The density of the positive electrode layer was reduced to 1.8 g / cm² using a roller press. 3 The process was adjusted, resulting in the formation of a positive electrode blank. The positive electrode blank was vacuum-dried at 120 °C for 12 hours. After drying, the positive electrode blank was punched to form a disc-shaped sample (14 mm diameter).

[0161] A button cell was assembled inside a glove box. The cell configuration is described as follows. Working electrode: Disc-shaped sample (positive electrode) Counter electrode: Li foil sheet Separator: Porous polymer film Electrolyte solution: “EC / DMC=3 / 7 (by volume)”, LiPF6 (1 mol / L) Output properties

[0162] The DCIR was measured according to the procedure described below. It can be assumed that the lower the DCIR, the better the output properties.

[0163] The first charging and discharging of the button cell takes place under the following conditions. Mode: Constant current constant voltage mode (CCCV) Rate: 0.01 C Lower limit of voltage: 3.0 V Maximum voltage: 4.3 V

[0164] "C" is a symbol that indicates the current rate (hourly rate). At a rate of 1 C, the stoichiometric capacity of a button cell is charged or discharged in 1 hour.

[0165] At a rate of 0.1 C, the button cell is then charged to a state of charge (SOC) of 60%. In a room temperature environment, the button cell is discharged at a rate of 1 C. Ten seconds after the start of the discharge, the voltage is measured. The voltage is measured in the same way at rates of 2 C, 3 C, 4 C, and 5 C. The measurement results are plotted in a two-dimensional coordinate system, where the horizontal axis represents the electric current and the vertical axis represents the voltage. The absolute value of the slope of the resulting line is considered the DCIR. The DCIR of each in Fig. The value of the sample shown is a relative value in relation to the DCIR of No. 1, which is defined as 100. - Results -

[0166] Referring to Table 1 in Fig. It can be observed that the performance characteristics tend to be improved when the width “X” of the first region on the line profile of P of the primary particles is between 0.5 and 20 nm.

[0167] Referring to Table 2 in Fig. The performance characteristics tend to be improved when the line profile of P of the secondary particles rises and falls and the mean distance between the valleys “Y” is between 11 and 290 nm.

[0168] Referring to Table 3 in Fig. Performance characteristics tend to be improved when the line profile of P of the secondary particles rises and falls and the peak-to-trough ratio “Z” is 0.90 or less.

[0169] Referring to Table 3 in Fig. Performance characteristics tend to be improved when the line profile of P of the secondary particles rises and falls and the peak-to-trough ratio “Z” is 0.69 or less.

[0170] Referring to Table 3 in Fig. Performance characteristics tend to be improved when the line profile of P of the secondary particles rises and falls and the peak-to-valley ratio “Z” is 0.48 or less. 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] WO 2016 / 158566

[0003]

Claims

[1] Active material for a positive electrode, comprising: primary particle (1) each of the primary particles (1) contains a phosphate compound of the olivine type, In a TEM-EDS line analysis of a cross-section of the primary particle (1) performed along a radial direction of the primary particle (1), a line profile of the signal intensity of phosphorus comprises a first region (1a) and a second region (1b), the first region (1a) is located at each end of the primary particle (1), the second area (1b) is located between the first areas (1a), the signal intensity of phosphorus in the first area (1a) is lower than the signal intensity of phosphorus in the second area (1b) and the width of the first region (1a) is between 0.5 and 20 nm. [2] Active material for the positive electrode according to claim 1, comprising: secondary particle (2) the secondary particles (2) contain the primary particles (1), and In a TEM-EDS line analysis of a cross-section of the secondary particle (2) performed along a radial direction of the secondary particle, a line profile of the signal intensity of phosphorus repeatedly rises and falls. [3] Active material for the positive electrode according to claim 2, wherein on the signal intensity line profile of phosphorus the mean distance between the valleys is 11 to 290 nm. [4] Active material for the positive electrode according to claim 2, wherein on the line profile the ratio of the lowest value of the signal intensity of phosphorus to the highest value of the signal intensity of phosphorus is 0.90 or less. [5] Active material for the positive electrode according to claim 4, wherein the ratio of the lowest value to the highest value is 0.69 or less. [6] Active material for the positive electrode according to claim 5, wherein the ratio of the lowest value to the highest value is 0.48 or less. [7] Active material for the positive electrode according to any one of claims 1 to 6, wherein the olivine-type phosphate compound comprises at least one compound selected from the group consisting of lithium iron phosphate, lithium manganese phosphate and lithium manganese iron phosphate. [8] Electrode, comprising: a positive electrode layer (11) the positive electrode layer (11) comprising the active material for the positive electrode according to any one of claims 1 to 6. [9] Battery comprising the electrode (10) according to claim 8. [10] The battery according to claim 9, which has a bipolar structure.

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