Negative electrode material, secondary battery and electric equipment

Abstract

The invention provides a negative electrode material, a secondary battery and electric equipment. The negative electrode material comprises a carbonaceous material and meets the following relational expression: 0.4 < = DV50 * S / [| P-OI / 4.8 | * 210] < = 1.1; dV50 [mu] m represents the corresponding particle size when the cumulative volume percentage of the negative electrode material reaches 50%; s m < 2 > / g represents the specific surface area of the negative electrode material; p g / cm < 3 > represents the powder compaction density of the negative electrode material under the pressure of 5T; oI represents the graphite orientation degree of the negative electrode material, and is a peak intensity ratio of a (004) diffraction peak to a (110) diffraction peak in an XRD pattern. By controlling the particle size, the specific surface area, the powder compaction density and the OI value of the carbon negative electrode material to meet a certain relationship, the battery can be endowed with excellent fast charging performance and cycling stability.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, in particular to a negative electrode material, a secondary battery, and an electrical device. Background Art

[0002] Secondary batteries, especially lithium-ion secondary batteries, have been widely used in many industries due to their advantages of high energy / power density, long cycle life, and pollution-free. With the increasing demand for cost reduction of power batteries, natural graphite negative electrode materials with lower costs are used in power batteries. However, compared with artificial graphite, natural graphite has poor fast charging and high-temperature performance, and it is difficult to meet the growing demand for fast charging performance of power batteries in the market. Therefore, it is necessary to develop artificial graphite negative electrode materials with low-cost advantages and good fast charging performance. Summary of the Invention

[0003] The purpose of the present application is to provide a negative electrode material, a secondary battery, and an electrical device to improve the fast charging performance of the battery, especially the cycling performance at high rates.

[0004] To achieve the above purpose, in the first aspect of the present application, a negative electrode material is provided. The negative electrode material includes a carbonaceous material, and the negative electrode material satisfies the following relational expression:

[0005] 0.4 ≤ D V 50 × S / [∣P - OI / 4.8∣ × 210] ≤ 1.1;

[0006] In the formula, D V 50μm represents the particle size corresponding to when the cumulative volume percentage of the negative electrode material reaches 50%;

[0007] Sm 2 / g represents the specific surface area of the negative electrode material;

[0008] P g / cm 3 represents the powder compaction density of the negative electrode material under a pressure of 5T;

[0009] OI represents the graphite orientation degree of the negative electrode material, which is the peak intensity ratio of the (004) diffraction peak to the (110) diffraction peak in the XRD pattern.

[0010] As an embodiment of the present application, the negative electrode material satisfies: 0.9 ≤ D V 50 × S / [∣P - OI / 4.8∣ × 210] ≤ 1.02.

[0011] As an embodiment of the present application, the powder compaction density P g / cm of the negative electrode material under a pressure of 5T 3 satisfies: P < 1.7.

[0012] As an embodiment of the present application, the specific surface area Sm of the negative electrode material 2 / g satisfies: 0.6 ≤ S ≤ 5.

[0013] As an embodiment of the present application, the particle size D of the negative electrode material V 50μm satisfies: 11 ≤ D V 50 ≤ 20.

[0014] As an embodiment of the present application, the particle size distribution of the negative electrode material satisfies: 1.0 ≤

[0015] (D V 90 - D V 10) / D V 50 ≤ 2.1; D V 90μm represents the particle size corresponding to when the cumulative volume percentage of the negative electrode material reaches 90%; D V 10μm represents the particle size corresponding to when the cumulative volume percentage of the negative electrode material reaches 10%; D V 50μm represents the particle size corresponding to when the cumulative volume percentage of the negative electrode material reaches 50%.

[0016] The powder compaction density of the negative electrode material satisfies: P g / cm 3 -Ag / cm 3 ≥ 0.2g / cm 3 ; P g / cm 3 represents the powder compaction density of the negative electrode material under 5T pressure; Ag / cm 3 represents the powder compaction density of the negative electrode material under 2T pressure.

[0017] As an embodiment of the present application, the powder compaction density A of the negative electrode material under 2T pressure satisfies: 1.35g / cm 3 ≤ Ag / cm 3 ≤ 1.50g / cm 3 .

[0018] As an embodiment of the present application, the graphitization degree of the negative electrode material is 92% - 96%.

[0019] As an embodiment of the present application, the powder OI value (graphite orientation degree) of the negative electrode material is 1 - 12.

[0020] As an embodiment of the present application, the specific capacity of the negative electrode material is 340mAh / g - 360mAh / g.

[0021] In the second aspect of the present application, a secondary battery is provided. The secondary battery includes a positive electrode plate, an electrolyte, a separator, and a negative electrode plate. The negative electrode plate includes a negative electrode current collector and a negative electrode material layer provided on at least one surface of the negative electrode current collector. The negative electrode material layer contains the negative electrode material described in the first aspect of the present application.

[0022] In the third aspect of the present application, an electrical device is further provided. The electrical device includes the secondary battery described in the second aspect of the present application.

[0023] Compared with the prior art, the beneficial effects of the present application are as follows:

[0024] By controlling the particle size, specific surface area, powder compaction density of the carbonaceous negative electrode material, and the OI value of the negative electrode material to satisfy a certain relationship, the present application can endow the battery with excellent fast charging performance and cycle stability. Specific Embodiments

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0026] In the present application, for the technical features described in an open-ended manner, a closed technical solution composed of the listed features is included, and an open technical solution including the listed features is also included.

[0027] In the present application, regarding numerical ranges, unless otherwise specified, the above numerical ranges are considered continuous and include the minimum and maximum values of the range, as well as each value between such minimum and maximum values. Further, when the range refers to integers, each integer between the minimum and maximum values of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all sub-ranges subsumed therein.

[0028] The reagents or instruments used in the present application that are not indicated by the manufacturer can all be conventional products obtained through commercial purchase.

[0029] In the first aspect of the present application, a negative electrode material is provided. The negative electrode material includes a carbonaceous material, and the negative electrode material satisfies the following relational expressions:

[0030] 0.4 ≤ D V 50 × S / [∣P - OI / 4.8∣ × 210] ≤ 1.1;

[0031] Wherein, D V 50 μm represents the particle size corresponding to when the cumulative volume percentage of the negative electrode material reaches 50%;

[0032] Sm 2 / g represents the specific surface area of the negative electrode material;

[0033] P g / cm 3 represents the powder compact density of the negative electrode material under a pressure of 5 T;

[0034] OI represents the graphite orientation degree of the negative electrode material, which is the ratio of the peak intensity of the (004) diffraction peak to the (110) diffraction peak in the XRD pattern.

[0035] The inventors of the present application have found through research that for a secondary battery using a carbon material as the negative electrode material, by controlling the particle size, specific surface area, powder compact density, and OI value of the carbon-based negative electrode material to meet a reasonable range, the fast charging performance of the secondary battery can be effectively improved, especially the cycle performance at high rates.

[0036] In some embodiments of the present application, D V The value of 50 × S / [∣P - OI / 4.8∣ × 210] can be any one of 0.430, 0.477, 0.540, 0.600, 0.690, 0.720, 0.810, 0.844, 0.893, 0.981, 1.107 or the range formed by any two numerical values.

[0037] In some embodiments of the present application, the powder compact density P g / cm of the negative electrode material under a pressure of 5 T 3 satisfies: P < 1.7. The smaller the powder compact density of the negative electrode material, the greater the distance between particles, the more ion channels, which is beneficial to the infiltration of the electrolyte, and thus beneficial to the rapid movement of ions, endowing the battery with good fast charging performance; however, due to the too large distance between particles, the contact probability and contact area between particles decrease, which is not conducive to electron conduction, increasing the discharge polarization, internal resistance, reducing the discharge capacity, and also prone to structural damage during the charge and discharge process, affecting the cycle life of the battery. And the inventors of the present application have found that when controlling the particle size, specific surface area, and powder compact density of the carbon-based negative electrode material of the negative electrode material to meet the above relationship, it is possible to improve the fast charging performance of the battery while ensuring that the battery has a relatively high discharge capacity and a relatively small resistance at a relatively small powder compact density, endowing the battery with good fast charging performance and discharge performance. The powder compact density P g / cm of the negative electrode material under a pressure of 5 T 3 Further preferably satisfies 1.61 ≤ P ≤ 1.70. In the present application, the value of P g / cm 3 can be 1.61 g / cm 3 、1.62 g / cm3 , 1.64 g / cm 3 , 1.66 g / cm 3 , 1.68 g / cm 3 , 1.70 g / cm 3 Any value or the range formed by any two numerical values among them.

[0038] In some embodiments of the present application, the powder compaction density of the negative electrode material further satisfies: P g / cm 3 -Ag / cm 3 ≥0.2 g / cm 3 ; P g / cm 3 represents the powder compaction density of the negative electrode material under 5T pressure; Ag / cm 3 represents the powder compaction density of the negative electrode material under 2T pressure. Controlling the powder compaction density of the negative electrode material to meet this condition can further improve the kinetic performance of the battery. The powder compaction density of the negative electrode material is further preferably satisfied: 0.20 g / cm 3 ≤P g / cm 3 -Ag / cm 3 ≤0.23 g / cm 3 . In the present application, the difference between the powder compaction density P g / cm 3 of the negative electrode material under 5T pressure and the powder compaction density Ag / cm 3 of the negative electrode material under 2T pressure can specifically be any value or the range formed by any two numerical values among 0.20 g / cm 3 , 0.21 g / cm 3 , 0.23 g / cm 3 .

[0039] In some embodiments of the present application, the powder compaction density Ag / cm 3 of the negative electrode material under 2T pressure satisfies: 1.39 g / cm 3 ≤Ag / cm 3 ≤1.50 g / cm 3 . In the present application, the value of Ag / cm 3 can be any value or the range formed by any two numerical values among 1.399 g / cm 3 , 1.407 g / cm 3 , 1.424 g / cm 3 , 1.463 g / cm 3 .

[0040] In some embodiments of the present application, the specific surface area S m 2 / g of the negative electrode material satisfies: 0.6 ≤ S ≤ 5. The S m2 The value of / g can be 0.60 m 2 / g, 1.10 m 2 / g, 1.89 m 2 / g, 2.12 m 2 / g, 3.09 m 2 / g, 3.54 m 2 / g, 4.23 m 2 / g, 5.00 m 2 Any one value or the range of any two numerical values in / g. In some embodiments of the present application, the specific surface area Sm 2 / g satisfies: 1.89 ≤ S ≤ 3.54.

[0041] In some embodiments of the present application, the particle size D of the negative electrode material V 50 μm satisfies: 11 ≤ D V 50 ≤ 20. The D V The value of 50 μm can be any one value or the range of any two numerical values in 11.0 μm, 14.0 μm, 14.5 μm, 16.2 μm, 19.0 μm, 20.0 μm. When the D V 50 of the negative electrode material is smaller, it is more beneficial to the infiltration of the electrolyte, the conduction speed of lithium ions inside the active material particles is faster, the battery kinetic performance is better, the polarization is smaller, the deposition of lithium on the material surface can be reduced, thereby reducing the safety risk, but too small is likely to cause too many side reactions and accelerate the loss of active lithium. When the D V 50 of the negative electrode material is larger, it is beneficial to improve the battery energy density, but the difficulty of electrolyte infiltration increases, the transmission of lithium ions inside the active material particles is blocked, the battery kinetic performance becomes worse, the polarization increases, resulting in the precipitation of lithium on the material surface and accelerating the attenuation of the battery capacity and the deterioration of the cycle performance. D V 50 within the above appropriate range can endow the battery with excellent kinetic performance and fast charging performance at the same time.

[0042] In some embodiments of the present application, the negative electrode material satisfies: 4 μm ≤ D V 10 μm ≤ 15 μm. The D V The value of 10 μm can be any one value or the range of any two numerical values in 4 μm, 5.1 μm, 7.6 μm, 8.9 μm, 11.2 μm, 12.5 μm, 15 μm.

[0043] In some embodiments of the present application, the negative electrode material satisfies: 20 μm ≤ D V 90 μm ≤ 45 μm. The D VThe value of 90μm can be any one of 20.0μm, 23.2μm, 28.5μm, 34.2μm, 41.7μm, 45.0μm or the range formed by any two of these values.

[0044] In some embodiments of the present application, the particle size distribution of the negative electrode material satisfies: 1.0 ≤ (D V 90 - D V 10) / D V 50 ≤ 2.1; D V 90μm represents the particle size corresponding to when the cumulative volume percentage of the negative electrode material reaches 90%; D V 10μm represents the particle size corresponding to when the cumulative volume percentage of the negative electrode material reaches 10%; D V 50μm represents the particle size corresponding to when the cumulative volume percentage of the negative electrode material reaches 50%. The (D V 90 - D V 10) / D V 50 can be any one of 1.00, 1.37, 1.61, 1.76, 1.92, 2.10 or the range formed by any two of these values. The smaller the particle size of the negative electrode material powder, the larger the corresponding specific surface area, more active sites, which is beneficial to ion conduction. However, if the particle size is too small, it is easy to cause agglomeration, and the negative electrode material powder is unevenly distributed on the surface of the negative electrode sheet, resulting in an uneven surface structure of the sheet and affecting the cycle life of the battery. Therefore, when the particle size, particle size distribution, and specific surface area of the negative electrode material powder are within the above suitable ranges, good kinetic performance can be imparted to the battery.

[0045] In some embodiments of the present application, the graphitization degree of the negative electrode material is 92% - 96%, specifically, it can be any one of 92.0%, 93.1%, 94.2%, 95.5%, 96.0% or the range formed by any two of these values. The graphitization degree refers to the perfection degree of graphite crystals in the material. The larger the graphitization degree, the higher the perfection degree of the graphite crystal structure, the fewer defects inside the crystal, providing more active centers and fast lithium-ion transport channels, reducing polarization, promoting the diffusion of lithium ions, and thus improving the fast charging performance of the battery.

[0046] In some embodiments of the present application, the OI value (graphite orientation degree) of the powder of the negative electrode material is 1 to 12, and specifically can be any value among 1.0, 3.5, 6.2, 6.4, 9.3, 12.0 or an interval range formed by any two numerical values. The OI value, full name is Orientation Index, is a parameter describing the degree of order of graphite sheet arrangement in graphite-based materials. It is obtained through XRD diffraction pattern analysis, and the specific calculation method is to characterize by the intensity ratio of the graphite (004) diffraction peak to the (110) diffraction peak. The smaller the OI value, the greater the probability that the layered structure in the negative electrode material is perpendicular to the surface of the current collector, and the greater the speed of lithium ion insertion and extraction, which is beneficial to the improvement of fast charging performance, but it is difficult to increase the compaction density of the electrode sheet after applying pressure, thereby limiting the increase of discharge capacity. Therefore, controlling the OI value of the powder of the negative electrode material within the above suitable range can endow the battery with good fast charging performance and discharge capacity.

[0047] In some embodiments of the present application, the specific capacity of the negative electrode material is 340 mAh / g to 360 mAh / g, and specifically can be any value among 340.0 mAh / g, 350.4 mAh / g, 360.0 mAh / g or an interval range formed by any two numerical values.

[0048] In the second aspect of the present application, a secondary battery is provided. The secondary battery includes a positive electrode sheet, an electrolyte, a separator and a negative electrode sheet. The negative electrode sheet includes a negative current collector and a negative electrode material layer provided on at least one surface of the negative current collector, and the negative electrode material layer contains the negative electrode material described in the first aspect of the present application.

[0049] In some embodiments of the present application, the positive electrode sheet includes a positive current collector and a positive electrode material layer provided on at least one surface of the positive current collector, and the positive electrode material layer includes a positive electrode material.

[0050] The present application does not limit the type of the positive electrode material, and any positive electrode material commonly used in the art can be used in the present application to prepare the secondary battery. The positive electrode material includes but is not limited to at least one of lithium iron phosphate (LiFePO4), lithium cobalt oxide (LiCoO2), lithium manganate (LiMnO2), lithium nickel oxide (LiNiO2), lithium nickel cobalt manganese oxide (general formula is Li a Ni x Co y Mn z O2, where x + y + z = 1, and 0 < x < 1, 0 < y < 1, 0 < z < 1, 0.9 ≤ a ≤ 1.1). The positive electrode material can also be doped with doping elements to improve the capacity and energy density of the battery.

[0051] In this application, the types of the positive current collector, negative current collector, separator, and electrolyte are not limited and can be selected according to requirements. Common current collector materials, separators, and electrolytes in the art can all be used in this application.

[0052] In some embodiments, the negative current collector is preferably made of copper foil, carbon-coated copper foil, or the like.

[0053] The positive current collector can be made of metal materials such as aluminum, stainless steel, nickel plating, titanium, tantalum, etc.; carbon materials such as carbon cloth and carbon paper; composite materials formed by polymers and metal layers. In some embodiments, the positive current collector is preferably made of aluminum foil.

[0054] In some embodiments, the type of the solvent used to form the positive electrode paste and / or negative electrode paste is not limited, as long as it can dissolve or disperse the positive electrode material, negative electrode material, conductive agent, binder, and dispersant.

[0055] In the secondary battery described in this application, the type of the separator is not particularly limited and can be selected according to actual requirements. The separator can be a polypropylene film, polyethylene film, polyvinylidene fluoride, spandex film, aramid film, or a multilayer composite film after coating modification.

[0056] In the secondary battery described in this application, the type of the electrolyte is not particularly limited and can be selected according to actual requirements.

[0057] In some embodiments of this application, the preparation of the secondary battery includes: stacking the positive electrode sheet, separator, and negative electrode sheet in sequence, with the separator between the positive and negative electrode sheets to play an isolation role, then winding them into a square bare battery core, installing it in a battery case, baking to remove water at 65°C to 95°C, injecting the electrolyte, sealing, and after processes such as standing, hot and cold pressing, forming, clamping, and grading, the secondary battery is obtained.

[0058] In some embodiments, the secondary battery may include an outer package, and the outer package can be a hard shell, such as a hard plastic shell, aluminum shell, steel shell, etc. The outer package of the secondary battery can also be a soft package, such as a pouch soft package, and the material of the soft package can be plastic, such as one or several of polypropylene, polybutylene terephthalate, polybutylene succinate, etc. The shape of the secondary battery is not particularly limited, and it can be cylindrical, square, or any other shape.

[0059] In the third aspect of the present application, an electrical device is provided, and the electrical device includes the secondary battery described in the second aspect of the present application. The electrical device can be an application device such as a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, and an electric tool. The vehicle can be a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle, an extended-range vehicle, etc.; the spacecraft includes an airplane, a rocket, a space shuttle, a spaceship, etc.; the electric toy includes a fixed or mobile electric toy, for example, a game console, an electric vehicle toy, an electric ship toy, an electric airplane toy, etc.; the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and a railway electric tool, for example, an electric drill, an electric grinding wheel, an electric wrench, an electric screwdriver, a hammer drill, an impact electric drill, a concrete vibrator, and a planer, etc. The embodiments of the present application do not impose special restrictions on the above devices.

[0060] The following are specific embodiments of the present application, and the technical solutions of the present application are further described in combination with the embodiments, but the present application is not limited to these embodiments. The reagents, methods, and equipment used in the present application are all conventional reagents, methods, and equipment in the technical field, unless otherwise specified.

[0061] Example 1

[0062] This embodiment provides a secondary battery, and the preparation method of the secondary battery includes the following steps:

[0063] Preparation of the positive electrode sheet

[0064] Mix the cathode material LiFePO4, the conductive agent carbon black, and the binder PVDF in a mass ratio of 95:3:2, add the solvent NMP, and stir under the action of a vacuum mixer to obtain the cathode slurry; uniformly coat the cathode slurry on both sides of the cathode current collector aluminum foil, air-dry at room temperature, transfer to an oven for further drying, and then obtain the cathode plate through rolling and cutting (the compaction density is 2.4 g / cm 3 );

[0065] Preparation of the negative electrode sheet

[0066] a. Prepare the anode material

[0067] Place the graphite in a crusher, adjust the main engine power to 350 kW, and the air intake volume to 55 m 2 / min, the feeding speed is 1200 kg / h, the classification frequency is 62 HZ, the pulverization is carried out for 30 min, the crushed materials are placed in a shaping machine, the feeding frequency is 58 HZ, the classification frequency is 43 HZ, the grinding disc spacing is 120 μm, the shaping rotation speed is 750 rmp, the shaping time is 20 min, 7.6% of PVP is added to the shaped materials and mixed in a fusion machine for 35 min, heated to 1240 °C at a heating rate of 1 °C / min, held for 3 h, after the calcined materials are cooled, they are dispersed in a VC mixer at a rotation speed of 60 rpm for 30 min, screened with a 350-mesh sieve, and the materials passing through the sieve are demagnetized to obtain the target carbon-containing anode material. The relevant physical properties of the anode material are shown in Table 1;

[0068] b. Preparation of anode electrode

[0069] The anode material, conductive agent carbon black, binder styrene-butadiene rubber, and dispersant sodium carboxymethylcellulose prepared in step a are mixed in a mass ratio of 96:1:1.5:1.5, and deionized water as a solvent is added, and the anode slurry is obtained by stirring under the action of a vacuum mixer; the anode slurry is uniformly coated on both sides of the anode current collector copper foil, air-dried at room temperature and then transferred to an oven for further drying, and then rolled and sliced to obtain the anode electrode (the compaction density is 1.60 g / cm 3 );

[0070] Preparation of the electrolyte

[0071] Lithium hexafluorophosphate is dissolved in an organic solvent (EC:DMC:EMC = 1:1:1 volume ratio) to obtain an electrolyte with a lithium ion concentration of 1 M;

[0072] Assembly of the secondary battery

[0073] The anode electrode is die-cut into an anode electrode with a size of 45 mm × 58 mm by a die-cutting machine, and the cathode electrode is die-cut into a cathode electrode with a size of 43 mm × 56 mm by a die-cutting machine; polypropylene (celgard2500, purchased from Celgard, USA) is used as the separator;

[0074] The cathode electrode, separator, and anode electrode are stacked in sequence, with the separator in the middle of the positive and negative electrodes, and then wound into a bare battery core and installed in a soft package shell. After processes such as top-side sealing, liquid injection (electrolyte), formation, and sorting, a lithium-ion secondary battery (soft package battery) is obtained.

[0075] Examples 2 to 16 and Comparative Examples 1 to 6

[0076] The main differences between Examples 2 to 16 and Comparative Examples 1 to 6 and Example 1 are that by adjusting process parameters such as crushing, shaping process, and coating amount in the preparation method of the anode material, the anode material prepared has the physical property parameters shown in Table 1.

[0077] Table 1

[0078]

[0079]

[0080] The following tests were conducted on the electrochemical performance of the above secondary battery:

[0081] The performance tests of the secondary battery are specifically as follows:

[0082] (1) Rate performance: At room temperature (25 ± 2 °C), the battery with a state of charge (SOC) of 0% was charged to 3.65 V at a current density of 0.33C, and the recorded capacity was C1; then, at room temperature, the battery with a SOC of 0% was charged to 3.65 V at a current density of 4C, and the recorded capacity was C2; calculate the capacity retention rate (%) = C2 / C1 × 100%, which is used as the test index for fast charging performance. The test results are shown in Table 2;

[0083] (2) Cycle performance: At 25 ± 2 °C, the battery was subjected to charge-discharge cycle tests at a charge-discharge rate of 1C / 1C in the range of 2.5 - 3.65 V, and the initial discharge specific capacity of the battery and the discharge specific capacity after 1000 cycles were recorded. Calculate the capacity retention rate after 1000 cycles = discharge specific capacity after 1000 cycles / initial discharge specific capacity × 100%.

[0084] Table 2

[0085]

[0086] It can be seen from the above results that:

[0087] In this application, by controlling the particle size, specific surface area, powder compaction density of the carbonaceous negative electrode material, and the OI value of the negative electrode material to satisfy a certain relationship, excellent fast charging performance and cycle stability can be imparted to the battery.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application rather than to limit the protection scope of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present application can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A negative electrode material, characterized in that, The negative electrode material includes a carbonaceous material, and the negative electrode material satisfies the following relational expression: 0.4 ≤ D V 50 × S / [|P - OI / 4.8| × 210] ≤ 1.1 where D V 50 μm represents the particle size corresponding to when the cumulative volume percentage of the negative electrode material reaches 50%; Sm 2 / g represents the specific surface area of the negative electrode material; P g / cm 3 represents the powder tap density of the negative electrode material under a pressure of 5T; OI represents the graphitization orientation degree of the negative electrode material, which is the peak intensity ratio of the (004) diffraction peak to the (110) diffraction peak in the XRD pattern.

2. The negative electrode material according to claim 1, wherein The negative electrode material satisfies: 0.9 ≤ D V 50 × S / [|P - OI / 4.8| × 210] ≤ 1.

02.

3. The negative electrode material according to claim 1, characterized in that, The negative electrode material satisfies at least one of the following conditions (i) to (iii): (i) The powder compaction density P of the negative electrode material under a pressure of 5T is g / cm 3 satisfies: P < 1.7; (ii) The specific surface area Sm of the negative electrode material 2 / g satisfies: 0.6 ≤ S ≤ 5; (iii) The said D V 50 μm satisfies: 11 ≤ D V 50 ≤ 20.

4. The negative electrode material according to claim 1, characterized in that, The particle size distribution of the negative electrode material satisfies: 1.0≤(D V 90 - D V 10) / D V 50≤2.1 D V 90 μm represents the particle size corresponding to when the cumulative volume percentage of the negative electrode material reaches 90%; D V 10 μm represents the particle size corresponding to when the cumulative volume percentage of the negative electrode material reaches 10%. D V 50 μm represents the particle size corresponding to when the cumulative volume percentage of the negative electrode material reaches 50%.

5. The negative electrode material according to claim 1, characterized in that, The powder tap density of the negative electrode material satisfies: P g / cm 3 -Ag / cm 3 ≥0.2 g / cm 3 P g / cm 3 represents the powder tap density of the negative electrode material under a pressure of 5T; Ag / cm 3 Indicates the powder compaction density of the negative electrode material under a pressure of 2T.

6. The negative electrode material according to claim 5, characterized in that, The negative electrode material satisfies: 1.35 g / cm 3 ≤ Ag / cm 3 ≤ 1.50 g / cm 3 .

7. The negative electrode material according to claim 1, wherein The negative electrode material satisfies at least one of the following conditions (iv) to (v): (iv) The graphitization degree of the negative electrode material is 92% to 96%; (v) The powder OI value of the negative electrode material is 1 to 12.

8. The negative electrode material according to claim 1, wherein The specific capacity of the negative electrode material is 340 mAh / g to 360 mAh / g.

9. A secondary battery, comprising a positive electrode plate, an electrolyte, a separator, and a negative electrode plate, characterized in that, The negative electrode sheet includes a negative electrode current collector and a negative electrode material layer provided on at least one surface of the negative electrode current collector, and the negative electrode material layer contains the negative electrode material according to any one of claims 1 to 8.

10. An electrical device, characterized in that, The electrical device includes the secondary battery according to claim 9.

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