Carbonaceous material, method for producing the same, secondary battery and power consumption device including the same

Abstract

The present application provides a carbonaceous material, a method for producing the same, a secondary battery and a power consumption device including the same. In the CO 2 adsorption test, at 0°C, when the relative pressure P / P 0 is between 10 -8 and 0.029, if the total CO 2 adsorption amount is A and the adsorption time is B, the carbonaceous material satisfies A / B ≧ 1.7 cm 3 / (g×h)STP, where STP is the standard state, P represents the test pressure of CO 2 , and P 0 represents the saturated vapor pressure of CO 2 at 0°C. The carbonaceous material of the present application can have high capacity and initial Coulomb efficiency.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and specifically relates to a carbonaceous material and a method for manufacturing the same, as well as a secondary battery and a power consumption device including the same.

Background Art

[0002] In recent years, secondary batteries have been widely applied in multiple fields such as energy storage power systems such as hydroelectric, thermal, wind, and solar power plants, and further in electric tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace, etc. With the application and popularization of secondary batteries, their energy density, service life, and rate characteristics have attracted increasing attention. Graphite is the most common negative electrode active material in secondary batteries, but its specific capacity is only 372 mAh / g, and there is very limited room for improving the energy density. In addition, graphite has a small interlayer distance, and the improvement of rate characteristics is also limited. Hard carbon, as a new negative electrode active material, can realize the rapid insertion and desorption of active ions during the charge and discharge process of secondary batteries, and has very high development potential. However, hard carbon has low capacity and initial Coulomb efficiency, and there are limitations in improving the energy density, service life, and rate characteristics of secondary batteries.

Summary of the Invention

[0003] An object of the present application is to provide a carbonaceous material and a method for manufacturing the same, as well as a secondary battery and a power consumption device including the same, which are intended to simultaneously improve the capacity and initial Coulomb efficiency of the carbonaceous material.

[0004] According to a first aspect of the present application, a carbonaceous material is provided, and the carbonaceous material is CO 2 In the adsorption test, at 0 °C, when the relative pressure P / P 0 is between 10 -8 and 0.029, and the total CO 2 adsorption amount is A and the adsorption time is B, the carbonaceous material satisfies A / B ≧ 1.7 cm 3 / (g×h) STP, where STP is the standard state, P represents the test pressure of CO 2 and P0 represents the saturated vapor pressure of CO 2 at 0°C.

[0005] In the process of research, the inventors of the present application found that in the CO 2 adsorption test at 0°C, when the relative pressure P / P 0 is between 10 -8 and 0.029, the total CO 2 adsorption amount A and the ratio A / B of the adsorption time B of CO corresponding to the adsorption amount can reflect the content of the space suitable for storing active ions and reversibly desorbing and inserting them in the carbonaceous material. When A / B ≧ 1.7 cm 2 / (g×h) STP, it is considered that the adsorption rate of CO 3 is fast, there is a large amount of space suitable for storing active ions inside the carbonaceous material, and the utilization rate of the space is also high. Therefore, the carbonaceous material of the present application can have high capacity and initial Coulomb efficiency, and can simultaneously endow the secondary battery with high energy density, long service life and good rate performance. 2 In any embodiment of the present application, 1.7 cm

[0006] / (g×h) STP ≦ A / B ≦ 20 cm 3 / (g×h) STP, and optionally, 3.0 cm 3 / (g×h) STP ≦ A / B ≦ 20 cm 3 / (g×h) STP. At this time, there is more space suitable for storing active ions inside the carbonaceous material and / or the utilization rate of the space is higher, thereby further improving the capacity and initial Coulomb efficiency of the carbonaceous material. 3 In any embodiment of the present application, B ≧ 5 h, and optionally, 5 h ≦ B ≦ 10 h. When the adsorption time B of CO

[0007] is long, it is considered that there is a large amount of space suitable for storing active ions inside the carbonaceous material, thereby increasing the capacity of the carbonaceous material. 2 In any embodiment of the present application, A ≧ 10 cm

[0008] ​3 / gSTP, and optionally, 15 cm 3 / gSTP ≤ A ≤ 200 cm 3 / gSTP. When the total adsorption amount A of CO 2 is high, it is considered that there are many spaces suitable for storing active ions contained inside the carbonaceous material, thereby increasing the capacity of the carbonaceous material.

[0009] In any embodiment of the present application, the true density ρ of the carbonaceous material is ≤ 1.45 g / cm 3 and optionally 1.0 g / cm 3 ~1.45 g / cm 3 . When the true density of the carbonaceous material satisfies the above specific range, it helps to further improve the capacity and initial coulombic efficiency of the carbonaceous material.

[0010] In any embodiment of the present application, the carbonaceous material includes a plurality of nanopore structures, and optionally, the carbonaceous material includes a plurality of pore structures with a pore diameter of 10 nm or less.

[0011] In any embodiment of the present application, in the Raman spectrum of the carbonaceous material, I d / I g is 0.90 to 1.25, and optionally 1.05 to 1.15, and I d represents the d-band peak intensity of the Raman shift in the range of 1350 ± 50 cm -1 , and I g represents the g-band peak intensity of the Raman shift in the range of 1580 ± 50 cm -1 . At this time, the degree of order of the structure of the carbonaceous material is appropriate, whereby the carbonaceous material has a higher capacity and a higher initial coulombic efficiency, and at the same time has good rate characteristics.

[0012] In any embodiment of the present application, the interlayer distance of the (002) crystal plane of the carbonaceous material is ≥ 0.37 nm, and optionally 0.37 nm to 0.42 nm.

[0013] In any embodiment of the present application, in the X-ray diffraction spectrum of the carbonaceous material, the value of 2θ corresponding to the (002) crystal plane peak is between 22° and 24°.

[0014] In any embodiment of the present application, the volume-based particle size distribution Dv50 of the carbonaceous material is 3 μm to 15 μm, and optionally 4 μm to 6 μm.

[0015] In any embodiment of the present application, the volume-based particle size distribution Dv90 of the carbonaceous material is 8 μm to 30 μm, and optionally 9 μm to 12 μm.

[0016] When the volume-based particle size distribution Dv50 and / or Dv90 of the carbonaceous material is within an appropriate range, it is advantageous for improving the transport characteristics of active ions and electrons, thereby further improving the rate characteristics of the secondary battery.

[0017] In any embodiment of the present application, the specific surface area of the carbonaceous material is 1 m 2 / g to 10 m 2 / g, and optionally 1 m 2 / g to 5 m 2 / g. When the specific surface area of the carbonaceous material is within an appropriate range, the carbonaceous material can have both higher capacity and initial Coulomb efficiency, and further can have better rate characteristics.

[0018] In any embodiment of the present application, the tap density of the carbonaceous material under a force of 50000 N is 0.90 g / cm 3 to 1.05 g / cm 3 and optionally 0.93 g / cm 3 to 1.02 g / cm 3 When the tap density of the carbonaceous material is within an appropriate range, the tap density of the negative electrode sheet can be increased to improve the energy density of the secondary battery.

[0019] In any embodiment of the present application, the tap density of the carbonaceous material is 0.80 g / cm 3 to 0.95 g / cm3 and selectively 0.85 g / cm 3 ~0.9 g / cm 3 is. When the tap density of the carbonaceous material is within an appropriate range, the green density of the negative electrode sheet can be increased to improve the energy density of the secondary battery.

[0020] According to the second aspect of the present application, a method for producing a carbonaceous material including the following steps S10 to S50 is provided.

[0021] In step S10, a raw material that is an organic carbon source is provided.

[0022] In step S20, the raw material is pulverized.

[0023] In step S30, a washing and impurity removal treatment is performed on the pulverized raw material obtained in step S20 to remove impurities. The washing and impurity removal treatment process includes at least an acidic solution washing step and an alkaline solution washing step.

[0024] In step S40, the raw material after washing and removing impurities obtained in step S30 is placed in a firing furnace, and under the condition that the furnace pressure is ≤ -2 kPa in a protective gas atmosphere, it is heated to a first temperature T1 at a first rate of ≥ 20 °C / min, and further heat-insulated at the first temperature T1 for a first time t1. After completion, a low-temperature preliminary carbonization treatment is performed to obtain pre-pyrolyzed carbon.

[0025] In step S50, the pre-pyrolyzed carbon obtained in step S40 is placed in a firing furnace, and under the conditions that the furnace pressure is ≤ -2 kPa and the packing density is ≤ 0.6 g / cm 3 , it is heated to a second temperature T2 at a second rate, and further heat-insulated at the second temperature T2 for a second time t2 to perform a high-temperature carbonization treatment to obtain a carbonaceous material. The carbonaceous material has a CO 2 adsorption test. At 0 °C, when the relative pressure P / P 0 is between 10 -8 and 0.029, and the total CO 2 adsorption amount is A and the adsorption time is B, the carbonaceous material satisfies A / B ≥ 1.7 cm3 / (g×h) meets STP, where STP is the standard state and P represents the 2 test pressure of CO, and P 0 represents the 2 saturated vapor pressure of CO at 0 °C.

[0026] The carbonaceous material obtained by the manufacturing method provided by the present application has many active ion storage spaces and a high space utilization rate. As a result, the carbonaceous material can have a high capacity and a high initial coulombic efficiency, and can endow the secondary battery with a high energy density, a long service life, and good rate characteristics at the same time.

[0027] In any embodiment of the present application, in step S10, the organic carbon source includes one or more of biomass materials and thermoplastic resin materials.

[0028] In any embodiment of the present application, the biomass material includes one or more of energy crops and biomass wastes.

[0029] In any embodiment of the present application, the thermoplastic resin material includes one or more of phenolic resin, acrylic resin, polyvinyl chloride, polycarbonate, epoxy resin, polyoxymethylene, coumarone resin, and petroleum resin.

[0030] In any embodiment of the present application, in step S30, the washing and impurity removal treatment process includes, in sequence, the steps of washing with an acidic solution, washing with water, washing with an alkaline solution, washing with water, and drying, or, in step S30, the washing and impurity removal treatment process includes, in sequence, the steps of washing with an alkaline solution, washing with water, washing with an acidic solution, washing with water, and drying.

[0031] In any embodiment of the present application, the H + concentration of the acidic solution is 0.1 mol / L to 6 moL / L, and optionally 1 mol / L to 6 moL / L.

[0032] In any embodiment of the present application, the washing temperature of the acidic solution is 10°C to 95°C, and optionally 30°C to 95°C.

[0033] In any embodiment of the present application, the washing time of the acidic solution is 1 h to 24 h, and optionally 10 h to 24 h.

[0034] In any embodiment of the present application, the solute of the acidic solution contains one or more of hydrochloric acid, nitric acid, sulfuric acid, and perchloric acid, and the solvent is water.

[0035] H of the acidic solution + By adjusting one or more of the concentration, washing temperature, washing time, type of solute, etc. within the above ranges, it is advantageous to achieve sufficient washing and better remove metal impurities.

[0036] In any embodiment of the present application, the OH of the alkaline solution - The concentration is 0.1 mol / L to 6 moL / L, and optionally 1 mol / L to 6 moL / L.

[0037] In any embodiment of the present application, the washing temperature of the alkaline solution is 10°C to 95°C, and optionally 30°C to 95°C.

[0038] In any embodiment of the present application, the washing time of the alkaline solution is 1 h to 24 h, and optionally 10 h to 24 h.

[0039] In any embodiment of the present application, the solute of the alkaline solution contains NaOH, KOH, or a combination thereof, and the solvent is water.

[0040] OH of the alkaline solution - By adjusting one or more of the concentration, washing temperature, washing time, type of solute, etc. within the above ranges, it is advantageous to achieve sufficient washing.

[0041] In any embodiment of the present application, in step S40, the temperature T1 is 300°C to 600°C, and optionally 400°C to 500°C. When the first temperature T1 is within an appropriate range, it is advantageous to form a pore structure that penetrates, providing a rapid dissipation channel.

[0042] In any embodiment of the present application, in step S40, the time t2 is 1 h to 24 h, and optionally 6 h to 12 h.

[0043] In any embodiment of the present application, in step S40, the heating rate is 20°C / min to 35°C / min, and optionally 25°C / min to 30°C / min. This is advantageous for the carbonaceous material to have better high capacity and initial Coulombic efficiency.

[0044] In any embodiment of the present application, in step S40, the protective gas includes nitrogen gas, argon gas, helium gas, or a combination thereof.

[0045] In any embodiment of the present application, in step S40, the furnace internal pressure is -5 kPa to -2 kPa, and optionally -4.5 kPa to -3 kPa. This is advantageous for ensuring safe production.

[0046] In any embodiment of the present application, in step S50, the temperature T2 is 1000°C to 1600°C, and optionally 1200°C to 1400°C. When the second temperature T2 is within an appropriate range, it can bring about a closed pore effect on the pyrolytic carbon obtained by low-temperature preliminary carbonization treatment, thereby reducing the contact area between the carbonaceous material and the electrolyte, that is, reducing the consumption of active ions due to the formation of the SEI film and improving the initial Coulombic efficiency of the carbonaceous material. Furthermore, the pyrolytic carbon obtained by low-temperature preliminary carbonization treatment can be cyclically aromatized, thereby improving the orderliness and conductivity of the carbonaceous material, and at the same time removing excess O elements and H elements on the carbon skeleton structure, contributing to the formation of an ordered quasi-graphite microcrystalline structure.

[0047] In any embodiment of the present application, in step S50, the time t1 is 1 h to 24 h, and optionally 6 h to 12 h.

[0048] In any embodiment of the present application, in step S50, the heating rate is 1 °C / min to 10 °C / min, and optionally 3 °C / min to 5 °C / min. This is advantageous for improving the capacity of the carbonaceous material and / or the initial Coulomb efficiency.

[0049] In any embodiment of the present application, in step S50, the protective gas includes nitrogen gas, argon gas, helium gas, or a combination thereof.

[0050] In any embodiment of the present application, in step S50, the pressure inside the furnace is -5 kPa to -2 kPa, and optionally -4.5 kPa to -3 kPa. This is advantageous for ensuring safe production.

[0051] According to the third aspect of the present application, there is provided a secondary battery including a negative electrode sheet including the carbonaceous material of the first aspect of the present application or the carbonaceous material manufactured by the method of the second aspect of the present application.

[0052] According to the fourth aspect of the present application, there is provided a power consumption device including the secondary battery of the third aspect of the present application.

[0053] The carbonaceous material provided by the present application has many active ion storage spaces and a high space utilization rate. As a result, the carbonaceous material can have a high capacity and an initial Coulomb efficiency, and can simultaneously endow the secondary battery with a high energy density, a long service life, and good rate characteristics. The power consumption device of the present application includes the secondary battery provided by the present application, and thus has at least the same advantages as the secondary battery.

Brief Description of the Drawings

[0054] To more clearly explain the technical solutions in the embodiments of this application, the drawings necessary for the embodiments of this application are briefly described below. It should be understood that the drawings shown below are only some embodiments of this application, and those skilled in the art can further obtain other drawings based on these drawings without creative efforts.

[0055]

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Figure 10

[0056] In the drawings, the drawings are not drawn according to the actual ratio.

Description of Reference Signs

[0057] 1 Battery pack 2 Upper housing 3 Lower housing 4 Battery module 5 Battery Cell 51 Housing 52 Electrode Assembly 53 Cover Plate

Best Mode for Carrying Out the Invention

[0058] Hereinafter, embodiments specifically disclosing the carbonaceous material of the present application, its manufacturing method, and the secondary battery and power consumption device including the same will be described in detail with appropriate reference to the drawings. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and overlapping descriptions of substantially the same structures may be omitted. This is to prevent the following description from becoming unnecessarily redundant and to facilitate the understanding of those skilled in the art. Also, the drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0059] The "range" disclosed in this application is defined in the form of a lower limit and an upper limit. A given range is defined by selecting one lower limit and one upper limit, and the selected lower limit and upper limit define the boundaries of a specific range. A range defined in such a way may or may not include the values at both ends, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60 - 120 and 80 - 110 are listed for a specific parameter, ranges of 60 - 110 and 80 - 120 are also understood to be expected. Also, if the minimum range values 1 and 2 are listed, and the maximum range values 3, 4, and 5 are listed, ranges of 1 - 3, 1 - 4, 1 - 5, 2 - 3, 2 - 4, and 2 - 5 are all contemplated. In this application, unless otherwise stated, the numerical range "a - b" means an abbreviated representation of any combination of real numbers between a and b, and both a and b are real numbers. For example, the numerical range "0 - 5" means that all real numbers between "0 - 5" are all listed in this specification, and "0 - 5" is only an abbreviated representation of combinations of these numerical values. Also, when a certain parameter is expressed as an integer ≧ 2, it is equivalent to disclosing that the parameter is, for example, the integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0060] All embodiments and selectable embodiments of this application can, unless otherwise specified, be combined with each other to form new technical solutions, and such technical solutions should be regarded as being included in the disclosure of this application.

[0061] All technical features and selectable technical features of this application can, unless otherwise specified, be combined with each other to form new technical solutions, and such technical solutions should be regarded as being included in the disclosure of this application.

[0062] All steps of this application can be carried out in sequence or randomly, preferably in sequence, unless otherwise specified. For example, if the method includes steps (a) and (b), it indicates that the method may include steps (a) and (b) carried out in sequence, or steps (b) and (a) carried out in sequence. For example, when it is said that the above-mentioned method may further include step (c), it indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0063] As used in this application, "comprising" and "including" indicate both open and closed forms, unless otherwise specified. For example, the above "comprising" and "including" can indicate that other components not listed may also be included or comprised, or that only the listed components may be included or comprised.

[0064] In this application, unless otherwise specified, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by either A being true (or existing) and B being false (or not existing), or A being false (or not existing) and B being true (or existing), or both A and B being true (or existing).

[0065] Unless otherwise specified, the terms used in this application have the same meaning as generally understood by those skilled in the art.

[0066] Unless otherwise specified, the numerical values of each parameter described in this application can be measured by various test methods commonly used in this field. For example, they can be measured according to the test methods shown in this application.

[0067] In the present application, unless otherwise specified, the term "active ion" means an ion that can be inserted and extracted between the positive electrode and the negative electrode of a secondary battery, including but not limited to lithium ions, sodium ions, etc.

[0068] In the present application, the terms "a plurality of" and "plural" mean two or more.

[0069] According to the definition of the International Union of Pure and Applied Chemistry (IUPAC), micropores mean pores with a pore diameter < 2 nm, mesopores mean pores with a pore diameter of 2 nm to 50 nm, and macropores mean pores with a pore diameter > 50 nm.

[0070] In the context of the present application, whenever the term "micropore" exists, it refers to pores with a pore diameter < 2 nm; whenever the term "mesopore" exists, it refers to pores with a pore diameter of 2 nm to 50 nm; and whenever the term "macropore" exists, it refers to pores with a pore diameter > 50 nm.

[0071] In the context of the present application, the term "small mesopore" refers to pores with a pore diameter of 2 nm to 10 nm, and the term "large mesopore" refers to pores with a pore diameter greater than 10 nm and less than or equal to 50 nm.

[0072] With the application and popularization of secondary batteries, increasing attention has been paid to their energy density, service life, and rate performance. The characteristics of the negative electrode active material can determine to some extent the energy density, service life, and safety of secondary batteries. Graphite (including natural graphite and synthetic graphite) is the most common negative electrode active material in secondary batteries, but its theoretical capacity is only 372 mAh / g, and there is very limited room for improving the energy density. In addition, graphite has a small interlayer distance, and the improvement of rate performance is also limited, unable to meet the actual needs for high-rate-performance secondary batteries.

[0073] Compared with graphite, the spacing between the hard carbon layers is larger, thus being advantageous for the rapid insertion and extraction of active ions. As a result, the secondary battery can have excellent low-temperature characteristics, output characteristics, and safety. Especially in the field of power batteries, hard carbon has unique advantages. However, many of the currently commercialized hard carbons belong to the low-capacity type, with low capacity and first Coulomb efficiency. For example, the capacity is generally between 200 mAh / g and 280 mAh / g, and the first Coulomb efficiency is generally less than 80%. Therefore, it is quite restricted in actual applications.

[0074] Therefore, how to simultaneously improve the capacity and first Coulomb efficiency of hard carbon remains an urgent technical problem to be solved.

[0075] In view of this, the first aspect of the embodiments of the present application provides a carbonaceous material that has both high capacity and first Coulomb efficiency, so that the secondary battery can have high energy density, long service life, and good rate characteristics.

[0076] Carbonaceous material In the CO adsorption test of the carbonaceous material provided by the present application 2 at 0 °C, when the relative pressure P / P 0 is between 10 -8 and 0.029 for CO 2 and the total adsorption amount is A and the adsorption time is B, the carbonaceous material satisfies A / B ≧ 1.7 cm 3 / (g×h) STP, where STP is the standard state (Standard Temperature and Pressure), P represents the test pressure of CO 2 , and P 0 represents the saturated vapor pressure of CO 2 at 0 °C.

[0077] In the present application, the CO of the carbonaceous material 2The adsorption test can be carried out with reference to GB / T 21650.2-2008 and measured using a surface area and pore size analyzer. The test apparatus can use the ASAP 2460 type surface area and pore size analyzer of Micromeritics, USA.

[0078] Compared with the currently commercialized hard carbon, the carbonaceous material provided by the present application has high capacity and initial coulombic efficiency. Although the mechanism is not yet clear, the inventors consider that one possible reason is that the carbonaceous material provided by the present application has a unique pore structure, with a large amount of active ion storage space and high space utilization rate, which enables the easy insertion, storage, and desorption of active ions, and thus it is speculated that the carbonaceous material provided by the present application can have high capacity and initial coulombic efficiency.

[0079] In the process of research, the inventors of the present application found that in the CO 2 adsorption test of the carbonaceous material, at 0 °C, when the relative pressure P / P 0 is between 10 -8 and 0.029, the ratio A / B of the total CO 2 adsorption amount A to the CO 2 adsorption time B corresponding to this adsorption amount can reflect the content of the space suitable for storing active ions and reversibly desorbing and inserting them in the carbonaceous material. When A / B ≥ 1.7 cm 3 / (g×h) STP, the CO 2 adsorption rate is fast, there is a large amount of space suitable for storing active ions inside the carbonaceous material, and the space utilization rate is also high. Therefore, the carbonaceous material of the present application can have high capacity and initial coulombic efficiency, and can simultaneously endow the secondary battery with high energy density, long service life, and good rate performance.

[0080] When A / B is less than 1.7 cm 3 / (g×h) STP, the CO 2 adsorption rate is slow, there is less space suitable for storing active ions inside the carbonaceous material and / or the space utilization rate is low, and thus it is considered that the capacity of the carbonaceous material is low and the initial coulombic efficiency is also low.

[0081] In some embodiments, A / B is ≧2.0 cm 3 / (g×h) STP, ≧3.0 cm 3 / (g×h) STP, ≧4.0 cm 3 / (g×h) STP, ≧5.0 cm 3 / (g×h) STP, ≧6.0 cm 3 / (g×h) STP, ≧7.0 cm 3 / (g×h) STP, ≧8.0 cm 3 / (g×h) STP. Optionally, 1.7 cm 3 / (g×h) STP ≦ A / B ≦ 20 cm 3 / (g×h) STP, 3.0 cm 3 / (g×h) STP ≦ A / B ≦ 20 cm 3 / (g×h) STP, 5.0 cm 3 / (g×h) STP ≦ A / B ≦ 20 cm 3 / (g×h) STP, 8.0 cm 3 / (g×h) STP ≦ A / B ≦ 20 cm 3 / (g×h) STP. At this time, there is more space suitable for storing active ions contained inside the carbonaceous material and / or the space utilization rate is higher, thereby further improving the capacity and the initial Coulomb efficiency of the carbonaceous material.

[0082] In some embodiments, B ≧ 5 h. For example, B may be ≧ 5 h, ≧ 5.5 h, ≧ 6 h, ≧ 6.5 h, ≧ 7 h, and optionally, 5 h ≦ B ≦ 10 h, 5.5 h ≦ B ≦ 10 h, 6 h ≦ B ≦ 10 h, 6.5 h ≦ B ≦ 10 h, 7 h ≦ B ≦ 10 h. When the adsorption time B of CO 2 is long, it is considered that there is a lot of space suitable for storing active ions contained inside the carbonaceous material, thereby increasing the capacity of the carbonaceous material. When the adsorption time B of CO 2 is short, the carbonaceous material reaches adsorption equilibrium in a short time, there is less space suitable for storing active ions contained inside the carbonaceous material and / or the space utilization rate is low, thereby the capacity of the carbonaceous material is low and the initial Coulomb efficiency is also considered to be low.

[0083] In some embodiments, A ≥ 10 cm 3 / gSTP. For example, A may be ≥ 18 cm 3 / gSTP, ≥ 20 cm 3 / gSTP, ≥ 30 cm 3 / gSTP, ≥ 50 cm 3 / gSTP, ≥ 60 cm 3 / gSTP, ≥ 80 cm 3 / gSTP, and optionally, 15 cm 3 / gSTP ≤ A ≤ 200 cm 3 / gSTP, 20 cm 3 / gSTP ≤ A ≤ 200 cm 3 / gSTP, 30 cm 3 / gSTP ≤ A ≤ 200 cm 3 / gSTP, 50 cm 3 / gSTP ≤ A ≤ 200 cm 3 / gSTP, 80 cm 3 / gSTP ≤ A ≤ 200 cm 3 / gSTP is also possible. When the total adsorption amount A of CO 2 is high, it is considered that there is a large amount of space suitable for storing active ions contained inside the carbonaceous material, thereby increasing the capacity of the carbonaceous material. When the total adsorption amount A of CO 2 is low, it is considered that there is little space suitable for storing active ions contained inside the carbonaceous material, thereby reducing the capacity of the carbonaceous material.

[0084] In some embodiments, the carbonaceous material includes a plurality of nanopore structures. Optionally, the carbonaceous material includes a plurality of pore structures with a pore diameter of 10 nm or less. In some embodiments, the carbonaceous material may further include one or more pore structures with a pore diameter greater than 10 nm.

[0085] In some embodiments, the true density ρ of the carbonaceous material is ≤ 1.45 g / cm 3 For example, the true density ρ of the carbonaceous material is ≤ 1.40 g / cm 3 ≤ 1.38 g / cm 3 ≤ 1.36 g / cm 3 ≤ 1.34 g / cm 3 ≤ 1.30 g / cm 3It may be. Optionally, the true density ρ of the carbonaceous material is 1.0 g / cm 3 ~1.45 g / cm 3 、1.0 g / cm 3 ~1.40 g / cm 3 、1.0 g / cm 3 ~1.38 g / cm 3 、1.0 g / cm 3 ~1.36 g / cm 3 、1.0 g / cm 3 ~1.34 g / cm 3 、1.0 g / cm 3 ~1.32 g / cm 3 、1.0 g / cm 3 ~1.30 g / cm 3 It may be. When the true density of the carbonaceous material satisfies the above specific range, it helps to further improve the capacity and the initial Coulomb efficiency of the carbonaceous material.

[0086] When the true density of the carbonaceous material is large, the standard liquid (for example, n-butanol) is likely to wet the inside of the carbonaceous material particles. At this time, the closed pore effect of the carbonaceous material is low, and the large mesopore structure and / or the large pore structure are rich. As a result, the pore structure and / or the small mesopore structure are likely to be exposed to the electrolyte, and the active ion storage space decreases, and it is considered that the capacity and the initial Coulomb efficiency of the carbonaceous material decrease.

[0087] When the true density of the carbonaceous material is small, it is considered that the pore structure and / or the small mesopore structure of the carbonaceous material are rich and the closed pore effect is good. At this time, the space into which the standard liquid (for example, n-butanol) enters is less than the actual pore space of the carbonaceous material. These pore structures that have not yet entered can store active ions. At the same time, at this time, the electrolyte also hardly enters the inside of the carbonaceous material particles, and the consumption of active ions when forming the solid electrolyte interface film (SEI film) also decreases. Furthermore, if the true density of the carbonaceous material is too low, it is not appropriate. In that case, since the closed pore effect of the carbonaceous material is good, there is a possibility that active ions are also difficult to insert and store.

[0088] In the present application, the true density of the carbonaceous material has the meaning known in the art and can be measured using devices and methods known in the art. For example, a test can be performed using the immersion volume substitution method based on Archimedes' principle, and n-butanol can be used as the standard liquid. A powder true density meter can be used as the test device.

[0089] In some embodiments, the carbonaceous material may have a regular or irregular shape. For example, the shape of the carbonaceous material may be an irregular polygon.

[0090] In some embodiments, the content of C element in the carbonaceous material may be ≧90 wt%, or optionally 90 wt% - 98 wt%.

[0091] In some embodiments, the content of O element in the carbonaceous material may be 2 wt% - 8 wt%.

[0092] In some embodiments, the content of H element in the carbonaceous material may be ≦0.3 wt%, or optionally 0.1 - 0.2 wt%.

[0093] In some embodiments, the content of N element in the carbonaceous material may be ≦0.3 wt%, or optionally 0.01 wt% - 0.1 wt%.

[0094] In some embodiments, the total content of C, O, H, and N elements in the carbonaceous material may be ≧99 wt%, or optionally 99 wt% - 99.5 wt%.

[0095] In some embodiments, the content of S element in the carbonaceous material may be ≦0.2 wt%, or optionally 0.01 wt% - 0.1 wt%.

[0096] In some embodiments, the content of Na element in the carbonaceous material may be ≤ 0.0164 wt%, and optionally ≤ 0.005 wt%.

[0097] In some embodiments, in the Raman spectrum of the carbonaceous material, I d / I g is 0.90 to 1.25, I d represents the d-band peak intensity in the Raman shift range of 1350 ± 50 cm -1 , and I g represents the g-band peak intensity in the Raman shift range of 1580 ± 50 cm -1 . For example, I d / I g may be 0.90, 0.95, 1.0, 1.05, 1.1, 1.15, 1.2, 1.25 or a range consisting of any of the above numerical values. Optionally, I d / I g may be 1.05 to 1.15.

[0098] The Raman spectrum of the carbonaceous material can be measured using a Raman spectrometer. During the measurement, 100 d-band peak intensities and g-band peak intensities are obtained, 100 I d / I g are calculated, and excluding the 30 largest and 30 smallest I d / I g , the average value of the remaining 40 I d / I g is taken as the I d / I g of the carbonaceous material. The measuring device may be a Horiba LabRAM HR800 Raman spectrometer. The measurement conditions may be a laser wavelength of 532 nm, a diffraction grating with 600 lines per mm, a 50x objective lens, an integration time of 10 s, an accumulation count of 3 times, and surface scanning.

[0099] The D band peak is derived from lattice defects of carbon atoms, and the G band peak is derived from in-plane vibrations of sp2 carbon atoms. In the structure of the carbonaceous material, the D band peak intensity is related to the number of structural defects of the carbonaceous material, and the G band peak intensity is related to the number of quasi-graphite crystallites in the structure of the carbonaceous material. Therefore, I d / I g can characterize the degree of order of the structure of the carbonaceous material. I d / I g The smaller it is, the higher the degree of order of the structure of the carbonaceous material, the higher the perfection of the carbon plane, the improvement of the initial Coulomb efficiency of the carbonaceous material, but the capacity decreases and the rate performance decreases. In the carbonaceous material of the present application, when I d / I g satisfies 0.90 to 1.25, the degree of order of the structure of the carbonaceous material is appropriate, whereby the carbonaceous material has a higher capacity and a higher initial Coulomb efficiency, and at the same time has good rate performance.

[0100] In some embodiments, the interlayer distance of the (002) crystal plane of the carbonaceous material is ≧0.37 nm, and optionally 0.37 nm to 0.42 nm.

[0101] In some embodiments, in the X-ray diffraction spectrum of the carbonaceous material, the value of 2θ corresponding to the (002) crystal plane peak is between 22° and 24°.

[0102] In the present application, the interlayer distance of the (002) crystal plane of the carbonaceous material can be tested by referring to JIS K 0131-1996 and JB / T 4220-2011 and using an X-ray diffractometer. The test device may be a Bruker D8 Discover X-ray diffractometer.

[0103] In some embodiments, the volume-based particle size distribution Dv50 of the carbonaceous material is 3 μm to 15 μm, and optionally 4 μm to 6 μm.

[0104] In some embodiments, the volume-based particle size distribution Dv90 of the carbonaceous material is 8 μm to 30 μm, and optionally 9 μm to 12 μm.

[0105] In some embodiments, the volume-based particle size distribution Dv50 of the carbonaceous material is 3 μm to 15 μm, and the volume-based particle size distribution Dv90 is 8 μm to 30 μm. Optionally, the volume-based particle size distribution Dv50 of the carbonaceous material is 4 μm to 6 μm, and the volume-based particle size distribution Dv90 is 9 μm to 12 μm.

[0106] When the volume-based particle size distribution Dv50 and / or Dv90 of the carbonaceous material is within an appropriate range, it is advantageous to improve the transport characteristics of active ions and electrons, thereby further improving the rate performance of the secondary battery.

[0107] In the present application, the volume-based particle size distributions Dv50 and Dv90 of the carbonaceous material have the meanings known in the art, which indicate the corresponding particle sizes when the cumulative volume distribution percentages of the material reach 50% and 90% respectively, and can be measured using devices and methods known in the art. For example, referring to GB / T 19077-2016 Laser Diffraction Method for Particle Size Distribution, it can be easily measured using a laser particle size analyzer. The test device may be a Mastersizer 2000E type laser particle size analyzer manufactured by Malvern Panalytical Ltd., UK.

[0108] In some embodiments, the specific surface area of the carbonaceous material is 1 m 2 / g to 10 m 2 / g, and optionally 1 m 2 / g to 5 m 2It may also be / g. When the specific surface area of the carbonaceous material is low, it helps to reduce the surface activity of the carbonaceous material, decrease the consumption of active ions due to the formation of the SEI film, thereby improving the initial Coulombic efficiency of the carbonaceous material and the secondary battery. When the specific surface area of the carbonaceous material is high, it helps to accelerate the transmission of active ions, thereby improving the rate performance of the secondary battery. Therefore, when the specific surface area of the carbonaceous material is within an appropriate range, the carbonaceous material can have both higher capacity and initial Coulombic efficiency, and furthermore can have better rate performance. Also, when the specific surface area of the carbonaceous material is within an appropriate range, it can have a stronger binding force between the carbonaceous material and the binder, thereby improving the cohesion and adhesion of the negative electrode sheet, reducing the volume expansion of the negative electrode sheet during the cycling process, and enabling the secondary battery to have better cycle performance.

[0109] In the present application, the specific surface area of the carbonaceous material has the meaning known in this field and can be measured using devices and methods known in this field. For example, referring to GB / T 19587-2017, it can be measured using a test method for analyzing the specific surface area by the nitrogen adsorption method and calculated by the BET (Brunauer Emmett Teller) method. The test for analyzing the specific surface area by the nitrogen adsorption method can be carried out using a ASAP 3020 type surface area and pore size analyzer of Micromeritics, USA.

[0110] In some embodiments, the tap density of the carbonaceous material under a force of 50000 N is 0.90 g / cm 3 ~1.05 g / cm 3 and optionally 0.93 g / cm 3 ~1.02 g / cm 3 When the tap density of the carbonaceous material is within an appropriate range, the tap density of the negative electrode sheet can be increased to improve the energy density of the secondary battery.

[0111] In the present application, the bulk density of the carbonaceous material has the meaning known in the art and can be measured using the devices and methods known in the art. For example, referring to the standard GB / T24533-2009, measurement may be carried out using an electronic pressure tester (which may be of the UTM7305 type, for example). An exemplary test method is as follows. Weigh 1 g of carbonaceous material powder and add it into a mold with a bottom area of 1.327 cm 2 and apply pressure up to 5000 kg (equivalent to 50000 N), hold the pressure for 30 s, then release the pressure and hold for 10 s, and record and calculate the bulk density of the carbonaceous material under the acting force of 50000 N.

[0112] In some embodiments, the tap density of the carbonaceous material is 0.80 g / cm 3 to 0.95 g / cm 3 and optionally 0.85 g / cm 3 to 0.9 g / cm 3 . When the tap density of the carbonaceous material is within an appropriate range, the bulk density of the negative electrode sheet can be increased, and the energy density of the secondary battery can be improved.

[0113] In the present application, the tap density of the carbonaceous material has the meaning known in the art and can be measured using the devices and methods known in the art. For example, referring to GB / T 5162-2006, measurement can be carried out using a powder tap density meter. The measurement device may use Dandong Baite BT-301.

[0114] Manufacturing method of carbonaceous material According to the second aspect of the embodiment of the present application, a method for manufacturing a carbonaceous material including the following steps S10 to S50 is provided. In step S10, a raw material which is an organic carbon source is provided. In step S20, the raw material is pulverized. In step S30, a washing and impurity removal treatment is performed on the pulverized raw material obtained in step S20 to remove impurities. The washing and impurity removal treatment process includes at least an acidic solution washing step and an alkaline solution washing step. In step S40, the washed and impurity-removed raw material obtained in step S30 is placed in a firing furnace, and under the condition that the furnace pressure is ≤ -2 kPa in a protective gas atmosphere, the temperature is raised to a first temperature T1 at a first rate of ≥ 20 °C / min, and further heat preservation treatment is performed at the first temperature T1 for a first time t1. After completion, a low-temperature preliminary carbonization treatment for obtaining pre-carbonized carbon is performed. In step S50, the pre-carbonized carbon obtained in step S40 is placed in a firing furnace, and under the conditions that the furnace pressure is ≤ -2 kPa and the packing density is ≤ 0.6 g / cm 3 under the condition of, the temperature is raised to a second temperature T2 at a second rate, and further heat preservation treatment is performed at the second temperature T2 for a second time t2. After completion, a high-temperature carbonization treatment for obtaining a carbonaceous material is performed. The carbonaceous material has a CO 2 adsorption test. At 0 °C, when the relative pressure P / P 0 is between 10 -8 and 0.029, taking the total CO 2 adsorption amount as A and the adsorption time as B, the carbonaceous material satisfies A / B ≥ 1.7 cm 3 / (g×h)STP, where STP is the standard state, P represents the test pressure of CO 2 , and P 0 represents the saturated vapor pressure of CO 2 at 0 °C.

[0115] The method for manufacturing the carbonaceous material of the present application includes a pulverization treatment process, a washing and impurity removal treatment process, a low-temperature preliminary carbonization treatment process, and a high-temperature carbonization treatment process.

[0116] Crushing can reduce the particle size of the raw material, which helps to obtain a carbonaceous material with the required size. In some embodiments, the volume-based particle size distribution Dv50 of the particles after crushing is 3 μm to 15 μm, and selectively 4 μm to 6 μm. In some embodiments, the volume-based particle size distribution Dv90 of the particles after crushing is 8 μm to 30 μm, and selectively 9 μm to 12 μm. In some embodiments, the volume-based particle size distribution Dv50 of the particles after crushing is 3 μm to 15 μm and the volume-based particle size distribution Dv90 is 8 μm to 30 μm, and selectively, the volume-based particle size distribution Dv50 of the particles after crushing is 4 μm to 6 μm and the volume-based particle size distribution Dv90 is 9 μm to 12 μm.

[0117] Washing and impurity removal treatment can remove inorganic impurities and water-soluble impurities in the raw material, and avoid the aggregation of metal impurities after being reduced to metal monomers in the subsequent high-temperature carbonization process. In the aggregation process of metal monomers, the carbon skeleton structure collapses, especially the pore structure and / or small mesopore structure collapses, resulting in a decrease in the active ion storage space of the obtained carbonaceous material, a decrease in capacity. At this time, the carbonaceous material reaches adsorption equilibrium in a short time, and the CO 2 adsorption rate slows down. Metal impurities also have catalytic activity, which intensifies the decomposition of the carbon skeleton structure in the pyrolysis process, and the pore structure tends to form large mesopore structures and / or large pore structures with large sizes. As a result, the proportion of the electrolyte wetting region inside the obtained carbonaceous material increases, the consumption of active ions due to the formation of the SEI film increases, the first irreversible capacity loss increases, and the first Coulombic efficiency decreases. Also, after the carbon skeleton structure collapses, its volume shrinks, which increases the true density of the carbonaceous material. The washing and impurity removal treatment process includes at least an acidic solution washing step and an alkaline solution washing step. The acidic solution is mainly used to remove metal impurities in the raw material, and the alkaline solution is mainly used to remove Si-containing impurities that do not react with acids in the raw material, etc., thereby ensuring sufficient removal of impurities.

[0118] The crushing process needs to be carried out before the washing and impurity removal processes. By doing so, when washing and removing impurities, as much surface of the raw material particles as possible can be exposed, enabling sufficient contact between the raw material particles and the cleaning liquid, and improving the impurity removal effect. If the crushing process is carried out after the washing and impurity removal processes, there is a possibility that the cleaning liquid cannot enter the large raw material particle phase, and furthermore, impurities deeply coated in the large raw material particle phase cannot be removed, resulting in a decrease in the impurity removal effect. In subsequent low-temperature preliminary carbonization treatment and high-temperature carbonization treatment processes, unremoved metal impurities are easily aggregated after being reduced to elemental metals, causing the carbon skeleton structure to collapse, leading to a decrease in the active ion storage space of the obtained carbonaceous material. At the same time, after the carbon skeleton structure collapses, the pore structure becomes discontinuous, and some pore structures cannot store active ions, resulting in a decrease in the capacity of the obtained carbonaceous material. At this time, the carbonaceous material reaches adsorption equilibrium in a short time and shows a slow adsorption rate of CO 2 . The unremoved metal impurities further have catalytic activity, intensifying the decomposition of the carbon skeleton structure during the pyrolysis process. The pore structure tends to form large mesopore structures and / or large pore structures with large sizes, thereby increasing the proportion of the electrolyte wetting region occupied inside the obtained carbonaceous material, increasing the consumption of active ions due to the formation of the SEI film, increasing the loss of the first irreversible capacity, and decreasing the first Coulombic efficiency. Also, after the carbon skeleton structure collapses, its volume shrinks, further increasing the true density of the carbonaceous material.

[0119] The low-temperature preliminary carbonization treatment helps in the formation of a through-pore structure, providing a rapid dissipation channel. In the low-temperature preliminary carbonization treatment process, a large number of covalent bonds between C, H, and O atoms are broken, and a certain through-channel structure is constructed in the carbon skeleton structure, which can provide a channel for dissipating the gas generated by pyrolysis in a short time in the subsequent high-temperature carbonization treatment process, avoiding the gas generated during pyrolysis from blocking the inside of the particles and forming carbon through secondary decomposition to block the pore structure. Furthermore, in the subsequent high-temperature carbonization treatment process, C-H is broken at around 700 °C - 800 °C, and H generated in a short time2 It can avoid violently colliding with the carbon skeleton structure to collapse the carbon skeleton structure and block the pore structure, thereby avoiding problems such as a decrease in the active ion storage space of the obtained carbonaceous material and a decrease in the space utilization rate. Also, when the carbon skeleton structure collapses, the pore structure is blocked, the difficulty of desorption of active ions increases, and the true density of the carbonaceous material increases.

[0120] During the low-temperature preliminary carbonization process, the temperature is raised at a rate of ≥20 °C / min. When the heating rate is slow, the formed carbon skeleton structure is well adjusted, and the introduced pore structure is small and discontinuous, insufficient to form a penetrating gas dissipation channel. In the subsequent high-temperature carbonization treatment process, the pore structure is easily blocked, the active ion storage space of the obtained carbonaceous material decreases, the space utilization rate decreases, and the capacity decreases. At this time, the carbonaceous material reaches adsorption equilibrium in a short time, and the adsorption rate of CO 2 becomes slow.

[0121] The furnace pressure during both the low-temperature preliminary carbonization treatment and the high-temperature carbonization treatment is ≤ -2 kPa. The inventors of the present application discovered during the research process that in the low-temperature preliminary carbonization treatment and the high-temperature carbonization treatment processes, the furnace pressure of the firing furnace affects the performance of the finally produced carbonaceous material. When the furnace pressure is too high during the low-temperature preliminary carbonization treatment, the gaseous small-molecule substances released by thermal decomposition cannot be immediately dissipated from the particle phase to the outside. These gaseous small-molecule substances are bound to the particle phase and are converted into carbon through thermal decomposition again, thereby blocking the pore structure and unable to provide a sufficient gas dissipation channel in the high-temperature carbonization treatment. Also, when the gaseous small-molecule substances released by thermal decomposition during the high-temperature carbonization treatment are blocked inside the particles and form carbon through secondary decomposition, the pore structure is blocked, the active ion storage space of the obtained carbonaceous material decreases, the space utilization rate decreases, resulting in a decrease in capacity. At this time, the carbonaceous material reaches adsorption equilibrium in a short time, and the adsorption rate of CO 2It shows that the adsorption rate becomes slow. When the furnace pressure is too high during the high-temperature carbonization treatment, the gaseous small-molecule substances released by pyrolysis cannot be immediately dissipated from the particle phase to the outside. These gaseous small-molecule substances are bound to the particle phase, converted into carbon through pyrolysis again, the pore structure is blocked, the active ion storage space of the obtained carbonaceous material decreases, the space utilization rate decreases, resulting in a decrease in capacity.

[0122] The filling density during the high-temperature carbonization treatment is ≤ 0.6 g / cm 3 And the inventors of the present application discovered in the research process that the filling density of the material during the high-temperature carbonization treatment also ultimately affects the performance of the produced carbonaceous material. When the filling density is too high, the deposition between materials becomes too tight, the gas dissipation channel is blocked, and some blocked gaseous small-molecule substances are decomposed again into carbon after heating and adhere to the surface of the carbonaceous material. Active ions cannot smoothly enter the pore structure, the utilization rate of the pore structure decreases, the capacity of the carbonaceous material decreases. At this time, the carbonaceous material reaches the adsorption equilibrium in a short time, and the adsorption rate of CO 2 becomes slow. Also, due to the deposition of carbon formed by pyrolysis on the surface of the obtained carbonaceous material particles, the difficulty of desorption of active ions increases, the initial Coulomb efficiency of the carbonaceous material decreases, and the density of the carbon formed by pyrolysis increases, resulting in an increase in the true density of the carbonaceous material.

[0123] Therefore, the carbonaceous material obtained by the manufacturing method provided by the present application has many active ion storage spaces and a high space utilization rate. Thereby, the carbonaceous material can have a high capacity and an initial Coulomb efficiency, and can simultaneously endow the secondary battery with a high energy density, a long service life, and good rate performance.

[0124] The manufacturing method of the second aspect of the embodiment of the present application can manufacture the carbonaceous material of any of the examples in the first aspect of the embodiment of the present application. The manufacturing method of the carbonaceous material provided by the present application has a simple process and is suitable for commercial production. The manufacturing method of the carbonaceous material provided by the present application does not require the addition of a conductive agent, nor does it require the addition of other auxiliaries. The carbonaceous material obtained by the manufacturing method provided by the present application has a lower heteroatom content.

[0125] In the present application, the "organic carbon source" is a general term for substances rich in carbon elements and capable of forming carbonaceous materials. In some embodiments, in step S10, the organic carbon source may include one or more of biomass materials and thermoplastic resin materials. Optionally, the organic carbon source includes biomass materials. In some embodiments, in step S10, the organic carbon source may further include only biomass materials.

[0126] As the biomass material, materials known in the art suitable for the production of carbonaceous materials can be used. In some embodiments, the biomass material may include one or more of energy crops and biomass waste. For example, the biomass material can include, but is not limited to, one or more of wood, straw, bamboo, bark, and husks.

[0127] In some embodiments, the thermoplastic resin material may include one or more of phenolic resin, acrylic resin, polyvinyl chloride, polycarbonate, epoxy resin, polyoxymethylene, coumarone resin, and petroleum resin.

[0128] In some embodiments, in step S20, for the pulverization, a process known in the art suitable for pulverization in the production of carbonaceous materials can be used. For example, the pulverization can include, but is not limited to, ball mill pulverization or jet mill pulverization.

[0129] The order of acid solution washing and alkaline solution washing is not particularly limited. In some embodiments, in step S30, the washing and impurity removal process includes, in sequence, the steps of acid solution washing, water washing, alkaline solution washing, water washing, and drying. In some embodiments, in step S30, the washing and impurity removal process includes, in sequence, the steps of alkaline solution washing, water washing, acid solution washing, water washing, and drying. Deionized water may be used for water washing, and the number of times of water washing may be once or multiple times. The water washing process is considered complete when the pH of the filtrate becomes neutral (i.e., pH is 7 ± 0.5). Drying may be air drying or vacuum drying, and the drying process is considered complete when the mass change rate of the material becomes <0.1 wt% at 2-hour intervals.

[0130] The types of solutes, concentrations, washing temperatures, washing times, and other parameters of the acid solution and alkaline solution of the present application are not particularly limited, as long as it can be guaranteed that impurities can be sufficiently removed.

[0131] In some embodiments, in step S30, the H + concentration of the acid solution is 0.1 mol / L to 6 moL / L, and optionally 1 mol / L to 6 moL / L.

[0132] In some embodiments, in step S30, the washing temperature of the acid solution is 10°C to 95°C, and optionally 30°C to 95°C.

[0133] In some embodiments, in step S30, the washing time of the acid solution is 1 h to 24 h, and optionally 10 h to 24 h.

[0134] In some embodiments, in step S30, the solute of the acid solution includes one or more of hydrochloric acid, nitric acid, sulfuric acid, and perchloric acid, and the solvent is water. Thereby, on the one hand, sufficient removal of metal impurities can be guaranteed, and on the other hand, no other impurity elements are introduced.

[0135] H of the acidic solution + By adjusting one or more of the concentration of H in the acidic solution, the washing temperature, the washing time, the type of solute, etc. within the above ranges, sufficient washing can be achieved, which is advantageous for better removal of metal impurities.

[0136] In some embodiments, in step S30, the OH - concentration of the alkaline solution is 0.1 mol / L to 6 mol / L, and optionally 1 mol / L to 6 mol / L.

[0137] In some embodiments, in step S30, the washing temperature of the alkaline solution is 10°C to 95°C, and optionally 30°C to 95°C.

[0138] In some embodiments, in step S30, the washing time of the alkaline solution is 1 h to 24 h, and optionally 10 h to 24 h.

[0139] In some embodiments, in step S30, the solute of the alkaline solution includes NaOH, KOH or a combination thereof, and the solvent is water. Thereby, on the one hand, sufficient removal of Si-containing impurities and the like can be guaranteed, and on the other hand, no other impurity elements are introduced.

[0140] OH of the alkaline solution - By adjusting one or more of the concentration of OH in the alkaline solution, the washing temperature, the washing time, the type of solute, etc. within the above ranges, it is advantageous to achieve sufficient washing.

[0141] In some embodiments, in step S40, the first rate may be 20°C / min to 35°C / min, and optionally 25°C / min to 30°C / min. This is advantageous for the carbonaceous material to have both better high capacity and initial Coulombic efficiency. When the heating rate is too fast during the low-temperature preliminary carbonization treatment, the temperature of the device becomes uncontrollable and it is easy to break through the set heat preservation temperature. When the material is higher than the first temperature T1, rapid decomposition occurs. At this time, the stability of the carbon skeleton structure deteriorates, and the pore structure and / or small mesopore structure may collapse. The active ion storage space of the obtained carbonaceous material decreases, the capacity decreases, and at this time, the carbonaceous material indicates reaching adsorption equilibrium in a short time. At the same time, the collapse fuses some pore structures to introduce a pore structure with a larger size, thereby increasing the proportion of the electrolyte wetting region in the obtained carbonaceous material, increasing the consumption of active ions due to the formation of the SEI film, increasing the loss of the first irreversible capacity, and decreasing the initial Coulombic efficiency. At this time, the carbonaceous material indicates a high true density.

[0142] In some embodiments, in step S40, the protective gas may include nitrogen gas, argon gas, helium gas, or a combination thereof.

[0143] In some embodiments, in step S40, the furnace internal pressure may be from -5 kPa to -2 kPa, and optionally from -4.5 kPa to -3 kPa. This is advantageous for ensuring safe production. When the furnace internal pressure is too small, the powder floats under the negative pressure action and dissipates into the furnace, contaminating the furnace, reducing the yield of the product. At the same time, the dust and protective gas are likely to enter the exhaust pipe, increasing the risk of dust explosion.

[0144] In some embodiments, in step S40, the first temperature T1 may be 300°C to 600°C. For example, it may be 300°C, 350°C, 400°C, 450°C, 500°C, 550°C, 600°C, or any range consisting of any of the above numerical values. Optionally, the first temperature T1 is 400°C to 500°C. When the first temperature T1 is within an appropriate range, it is beneficial for the formation of a through-pore structure and provides a rapid dissipation channel.

[0145] When the first temperature T1 is too high, there is not enough time for the carbon skeleton structure to stabilize, resulting in insufficient strength of the carbon skeleton structure. In the subsequent high-temperature carbonization process, C-H is cleaved at around 700°C to 800°C, and the H 2 generated in a short time collides violently with the carbon skeleton structure, making the carbon skeleton structure prone to collapse and the pore structure blocked. As a result, the active ion storage space of the obtained carbonaceous material decreases, the space utilization rate decreases, and the capacity decreases. At this time, the carbonaceous material reaches adsorption equilibrium in a short time, and the adsorption rate of CO 2 is shown to slow down.

[0146] When the first temperature T1 is too low, the covalent bonds between C, H, and O atoms basically remain stable, and a through-channel structure cannot be constructed in the carbon skeleton structure. In the subsequent high-temperature carbonization process, C-H is cleaved at around 700°C to 800°C, and the H 2 generated in a short time collides violently with the carbon skeleton structure, making the carbon skeleton structure prone to collapse and the pore structure blocked. As a result, the active ion storage space of the obtained carbonaceous material decreases, the space utilization rate decreases, and the capacity decreases. At this time, the carbonaceous material reaches adsorption equilibrium in a short time, and the adsorption rate of CO 2 is shown to slow down. Also, after the carbon skeleton structure collapses, its volume shrinks, further increasing the true density of the carbonaceous material.

[0147] In some embodiments, in step S40, the first time t1 is from 1 h to 24 h, for example, 2 h, 4 h, 6 h, 8 h, 10 h, 12 h, 14 h, 16 h, 18 h, 20 h, 22 h, 24 h, or may be in a range consisting of any of the above numerical values. Optionally, the first time t1 is from 6 h to 12 h. A person skilled in the art can select an appropriate first time within the above range based on the first temperature adopted. For example, when the first temperature is high, the first time can be appropriately shortened.

[0148] In some embodiments, in step S50, the second rate may be from 1 °C / min to 10 °C / min, for example, from 1 °C / min to 8 °C / min, from 1 °C / min to 5 °C / min, or from 3 °C / min to 5 °C / min. This is advantageous for improving the capacity and / or the initial Coulombic efficiency of the carbonaceous material. In the high-temperature carbonization process, when the heating rate is too fast, the gaseous small-molecule substances released during the thermal decomposition process of the preheated decomposed carbon cannot be conducted into the furnace immediately after dissipating from the particle phase to the surface and discharged by the protective gas in the furnace. These gaseous small-molecule substances are bound to the particle phase, converted into carbon through thermal decomposition again, the pore structure is blocked, and thus the active ion storage space of the obtained carbonaceous material decreases, the capacity decreases. At this time, the carbonaceous material reaches the adsorption equilibrium in a short time, and 2 the adsorption rate of CO indicates a slowdown. Also, when the heating rate is too fast, the gaseous small-molecule substances that are not released to the outside collide with the carbon skeleton structure, causing the carbon skeleton structure to collapse. As a result, the proportion of the electrolyte wetting region inside the obtained carbonaceous material increases, the consumption of active ions due to the formation of the SEI film increases, the loss of the first irreversible capacity increases, the initial Coulombic efficiency decreases, and at this time, the carbonaceous material indicates a high true density.

[0149] In some embodiments, in step S50, the protective gas may include nitrogen gas, argon gas, helium gas, or a combination thereof.

[0150] In some embodiments, in step S50, the furnace pressure may be from -5 kPa to -2 kPa, or alternatively from -4.5 kPa to -3 kPa. This is advantageous for ensuring safe production. In the high-temperature carbonization process, if the furnace pressure is too low, the powder will float under the negative pressure effect and dissipate into the furnace, contaminating the furnace, reducing the yield of the product, and at the same time, dust and protective gas are likely to enter the exhaust pipe, increasing the risk of dust explosion.

[0151] In some embodiments, in step S50, the second temperature T2 may be from 1000 °C to 1600 °C, for example, 1000 °C, 1050 °C, 1100 °C, 1150 °C, 1200 °C, 1250 °C, 1300 °C, 1350 °C, 1400 °C, 1450 °C, 1500 °C, 1550 °C, 1600 °C or any range consisting of any of the above numerical values. Alternatively, the second temperature T2 is from 1200 °C to 1400 °C. When the second temperature T2 is within an appropriate range, it can bring about a closed-pore effect on the pyrolytic carbon obtained by low-temperature preliminary carbonization, thereby reducing the contact area between the carbonaceous material and the electrolyte, that is, reducing the consumption of active ions due to the formation of the SEI film, and improving the initial Coulomb efficiency of the carbonaceous material. Furthermore, the pyrolytic carbon obtained by low-temperature preliminary carbonization can be cyclically aromatized, thereby improving the order and conductivity of the carbonaceous material, and at the same time, removing excess O and H elements on the carbon skeleton structure, contributing to the formation of an ordered pseudo-graphite microcrystalline structure.

[0152] When the second temperature T2 is too high, under a high-energy state, a large amount of pseudo-graphite microcrystalline structures fuse, the size of the pore structure of the obtained carbonaceous material increases and the quantity decreases, thereby reducing the active ion storage space and the capacity. At this time, it indicates that the carbonaceous material reaches adsorption equilibrium in a short time. At the same time, the interlayer distance of the carbonaceous material decreases, the difficulty of insertion and desorption of active ions increases, the initial Coulomb efficiency decreases, and the density of the carbon skeleton structure increases. At this time, the carbonaceous material is CO 2It indicates that the adsorption rate becomes slow. When the second temperature T2 is too low, many carbons with low stability remain in the carbon skeleton structure, resulting in a decrease in the number of pores formed in the carbonaceous material, a reduction in the active ion storage space, a decrease in capacity, and at this time, the carbonaceous material indicates that it reaches the adsorption equilibrium in a short time. Also, when the second temperature T2 is too low, a lot of O elements may exist without being removed, and after the O atoms are combined with the active ions, the active ions cannot be reversibly desorbed, resulting in a decrease in the capacity and the initial Coulomb efficiency of the carbonaceous material.

[0153] In some embodiments, in step S50, the second time t2 may be 1 h to 24 h, for example, 2 h, 4 h, 6 h, 8 h, 10 h, 12 h, 14 h, 16 h, 18 h, 20 h, 22 h, 24 h or a range consisting of any of the above numerical values. Optionally, the second time t2 is 6 h to 12 h. Those skilled in the art can select an appropriate second time within the above range according to the second temperature adopted. For example, when the second temperature is high, the second time can be appropriately shortened.

[0154] In some embodiments, the manufacturing method further includes step S60. In step S60, a secondary grinding treatment is performed to grind the carbonaceous material obtained in step S50. At this time, the partially aggregated carbonaceous material can be ground, thereby meeting the requirement of the required particle size and facilitating the manufacture of the negative electrode slurry and the negative electrode sheet. In some embodiments, this step may be omitted.

[0155] In some embodiments, the manufacturing method includes the following steps S10 to S50. In step S10, a raw material that is an organic carbon source is provided. In step S20, the raw material is pulverized. In step S30, a washing and impurity removal treatment is performed on the pulverized raw material obtained in step S20 to remove impurities. The washing and impurity removal treatment process includes at least an acidic solution washing step and an alkaline solution washing step. In step S40, the raw material after washing and removing impurities obtained in step S30 is placed in a firing furnace, and in a protective gas atmosphere, the furnace pressure is ≤ -2 kPa, optionally under the condition of -5 kPa to -2 kPa, at a first rate of ≥ 20 °C / min, optionally 20 °C / min to 35 °C / min, the temperature is raised to 300 °C to 600 °C, and then heat preservation treatment is performed at this temperature for 1 h to 24 h. After completion, a low-temperature preliminary carbonization treatment is performed to obtain pre-pyrolyzed carbon. In step S50, the pre-pyrolyzed carbon obtained in step S40 is placed in a firing furnace, and in a protective gas atmosphere, the furnace pressure is ≤ -2 kPa, optionally -5 kPa to -2 kPa, and the filling density is ≤ 0.6 g / cm 3 Under the condition of being, the temperature is raised to 1000 °C to 1600 °C at a second rate, and then heat preservation treatment is performed at this temperature for 1 h to 24 h. After completion, a high-temperature carbonization treatment is performed to obtain a carbonaceous material. The carbonaceous material is CO 2 In the adsorption test, at 0 °C, when the relative pressure P / P 0 is between 10 -8 and 0.029, and the total CO 2 adsorption amount is A and the adsorption time is B, the carbonaceous material satisfies A / B ≥ 1.7 cm 3 / (g×h)STP, where STP is the standard state, P represents the test pressure of CO 2 , and P 0 represents the saturated vapor pressure of CO 2 at 0 °C. Thus, the carbonaceous material can have a higher capacity and initial Coulomb efficiency, and can further improve the energy density, service life, and rate characteristics of the secondary battery.

[0156] Secondary battery According to the third aspect of the embodiment of the present application, a secondary battery is provided.

[0157] The secondary battery referred to in the embodiments or implementation forms of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the secondary battery referred to in the present application can include battery cells, battery modules, battery packs, etc. A battery cell is the smallest unit constituting a secondary battery and can realize the function of charge and discharge alone. The present application does not particularly limit the shape of the battery cell, and it may be cylindrical, rectangular, or any other shape. FIG. 1 shows a rectangular-structured battery cell 5 as an example.

[0158] In some embodiments, the battery cell includes an electrode assembly and an electrolyte, and the battery cell can further include an exterior material. The exterior material is used to enclose the electrode assembly and the electrolyte. The exterior material may be a rigid case such as a hard plastic case, an aluminum case, a steel case, etc. The exterior material may also be a soft pack such as a pouch-type soft pack. The material of the soft pack may be one or more of plastics, such as polypropylene (PP), polybutylene terephthalate (PBT), and polybutylene succinate (PBS).

[0159] The electrode assembly generally includes a positive electrode sheet, a negative electrode sheet, etc. In the charge and discharge process of the secondary battery, active ions reciprocate between the positive electrode sheet and the negative electrode sheet for insertion and desorption, and the electrolyte plays a role in conducting active ions between the positive electrode sheet and the negative electrode sheet. The electrode assembly can be manufactured through a winding process and / or a lamination process.

[0160] In some embodiments, as shown in FIG. 2, the exterior member may include a housing 51 and a cover plate 53. The housing 51 includes a bottom plate and side plates connected to the bottom plate, and a receiving cavity surrounded by the bottom plate and the side plates is formed. The housing 51 has an opening communicating with the receiving cavity, and the cover plate 53 is used to cover the opening to seal the receiving cavity. The electrode assembly 52 is enclosed in the receiving cavity. The number of electrode assemblies 52 included in the battery cell 5 may be one or more, and can be adjusted as needed.

[0161] In some embodiments of the present application, the battery cells can be assembled into a battery module. The number of battery cells included in the battery module may be plural, and the specific number can be adjusted according to the use and capacity of the battery module. FIG. 3 is a schematic diagram of a battery module 4 as an example. As shown in FIG. 3, in the battery module 4, a plurality of battery cells 5 can be arranged in sequence along the length direction of the battery module 4. Of course, they may be arranged in any other manner. Also, the plurality of battery cells 5 can be fixed by fasteners.

[0162] Optionally, the battery module 4 may further include an outer case having a receiving space for receiving a plurality of battery cells 5.

[0163] In some embodiments, the above battery module can be further assembled into a battery pack. The number of battery modules included in the battery pack can be adjusted according to the use and capacity of the battery pack. FIGS. 4 and 5 are schematic diagrams of a battery pack 1 as an example. As shown in FIGS. 4 and 5, the battery pack 1 can include a battery case and a plurality of battery modules 4 installed in the battery case. The battery case includes an upper housing 2 and a lower housing 3. The upper housing 2 is used to cover the lower housing 3 and form a sealed space for receiving the battery module 4. The plurality of battery modules 4 can be arranged in the battery case in any way.

[0164] [Negative electrode sheet] In some embodiments, the negative electrode sheet includes a negative electrode current collector and a negative electrode film layer provided on at least one surface of the negative electrode current collector. For example, the negative electrode current collector has two surfaces facing each other in its own thickness direction, and the negative electrode film layer is provided on one or both of the two opposing surfaces of the negative electrode current collector.

[0165] In some embodiments, the negative electrode film layer contains the carbonaceous material in the first aspect of the embodiments of the present application or the carbonaceous material manufactured by the method described in the second aspect of the embodiments of the present application. Thereby, the secondary battery can have high energy density, long service life and good rate characteristics at the same time.

[0166] In some embodiments, the negative electrode film layer can further contain other negative electrode active materials other than the above carbonaceous material. In some embodiments, the other negative electrode active materials include, but are not limited to, one or more of natural graphite, artificial graphite, soft carbon, silicon-based materials, tin-based materials, and lithium titanate. The silicon-based material can include one or more of silicon alone, silicon oxide, silicon carbon composite, silicon nitride composite, and silicon alloy material. The tin-based material can include one or more of tin alone, tin oxide, and tin alloy material.

[0167] In some embodiments, the negative electrode film layer selectively further contains a negative electrode conductive agent. The present application does not particularly limit the type of the negative electrode conductive agent. By way of example, the negative electrode conductive agent can include one or more of superconducting carbon, conductive graphite, acetylene black, carbon black, ketjen black, carbon dot, carbon nanotube, graphene, and carbon nanofiber.

[0168] In some embodiments, the negative electrode film layer selectively further includes a negative electrode binder. The present application does not particularly limit the type of the negative electrode binder. By way of example, the negative electrode binder can include one or more of styrene butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, aqueous acrylic resin (for example, polyacrylic acid PAA, polymethacrylic acid PMAA, sodium polyacrylate PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), and carboxymethyl chitosan (CMCS).

[0169] In some embodiments, the negative electrode film layer selectively further includes other auxiliaries. By way of example, the other auxiliaries can include a thickener, for example, sodium carboxymethyl cellulose (CMC), PTC thermistor material, and the like.

[0170] In some embodiments, the negative electrode current collector can use a metal foil or a composite current collector. As an example, a copper foil can be used as the metal foil. The composite current collector can include a polymer base material layer and a metal material layer formed on at least one surface of the polymer base material layer. By way of example, the metal material can include one or more of copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy. By way of example, the polymer base material layer can include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0171] The negative electrode film layer is generally formed by applying a negative electrode paste on a negative electrode current collector, drying it, and cold pressing it. The negative electrode paste is generally formed by dispersing a negative electrode active material, selectively a conductive agent, selectively a binder, and other selectable other auxiliaries in a solvent and stirring them uniformly. The solvent can be N-methylpyrrolidone (NMP) or deionized water, but is not limited thereto.

[0172] The negative electrode sheet does not exclude other additional functional layers other than the negative electrode film layer. For example, in some embodiments, the negative electrode sheet described in the present application is sandwiched between the negative electrode current collector and the negative electrode film layer, and further includes a conductive primer layer (for example, composed of a conductive agent and a binder) provided on the surface of the negative electrode current collector. In some embodiments, the negative electrode sheet described in the present application further includes a protective layer covering the surface of the negative electrode film layer.

[0173] [Positive electrode sheet] In some embodiments, the positive electrode sheet includes a positive electrode current collector and a positive electrode film layer provided on at least one surface of the positive electrode current collector. For example, the positive electrode current collector has two surfaces facing each other in its own thickness direction, and the positive electrode film layer is provided on one or both of the two opposing surfaces of the positive electrode current collector.

[0174] The positive electrode current collector can use a metal foil or a composite current collector. As an example, an aluminum foil can be used as the metal foil. The composite current collector can include a polymer base material layer and a metal material layer formed on at least one surface of the polymer base material layer. As an example, the metal material can include one or more of aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy. As an example, the polymer base material layer can include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0175] The positive electrode film layer generally includes a positive electrode active material, optionally a binder, and optionally a conductive agent. The positive electrode film layer is generally formed by applying a positive electrode paste onto the positive electrode current collector, drying it, and cold pressing it. The positive electrode paste is generally formed by dispersing a positive electrode active material, optionally a conductive agent, optionally a binder, and any other optional components in a solvent and stirring them uniformly. The solvent may be N-methylpyrrolidone (NMP), but is not limited thereto. As an example, the binder used in the positive electrode film layer can include one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorine-containing acrylate resin. As an example, the conductive agent used in the positive electrode film layer can include one or more of superconducting carbon, conductive graphite, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0176] As the positive electrode active material, a positive electrode active material for secondary batteries known in the art can be used.

[0177] When the secondary battery of the present application is a lithium-ion battery, the positive electrode active material can include, but is not limited to, one or more of lithium transition metal oxides, lithium-containing phosphates, and their respective modified compounds. Examples of the lithium transition metal oxides include, but are not limited to, lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and one or more of their respective modified compounds. Examples of the lithium-containing phosphates include, but are not limited to, lithium iron phosphate, a composite material of lithium iron phosphate and carbon, lithium manganese phosphate, a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, a composite material of lithium manganese iron phosphate and carbon, and one or more of their respective modified compounds.

[0178] In some embodiments, in order to further increase the energy density of the secondary battery, the positive electrode active material used in the lithium-ion battery can include one or more of lithium transition metal oxides and their modified compounds having the general formula Li a Ni b Co c M d O e A f where 0.8 ≦ a ≦ 1.2, 0.5 ≦ b < 1, 0 < c < 1, 0 < d < 1, 1 ≦ e ≦ 2, 0 ≦ f ≦ 1, M includes one or more selected from Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti, and B, and A includes one or more selected from N, F, S, and Cl.

[0179] For example, the positive electrode active material used in the lithium-ion battery is LiCoO 2 、LiNiO 2 、LiMnO 2 、LiMn 2 O 4 、LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O 2(NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM523), LiNi 0.6 Co 0.2 Mn 0.2 O 2 (NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811), LiNi 0.85 Co 0.15 Al 0.05 O 2 , LiFePO 4 and LiMnPO 4 can include one or more of these.

[0180] When the secondary battery of the present application is a sodium ion battery, the positive electrode active material can include, but is not limited to, one or more of sodium-containing transition metal oxides, polyanion materials (such as phosphates, fluorophosphates, pyrophosphates, sulfates, etc.), and Prussian blue-based materials.

[0181] For example, the positive electrode active material used in a sodium ion battery is NaFeO 2 , NaCoO 2 , NaCrO 2 , NaMnO 2 , NaNiO 2 , NaNi 1 / 2 Ti 1 / 2 O 2 , NaNi 1 / 2 Mn 1 / 2 O 2 , Na 2 / 3 Fe 1 / 3 Mn 2 / 3 O 2 , NaNi 1 / 3 Co 1 / 3 Mn 1 / 3 O 2 , NaFePO 4 , NaMnPO 4 , NaCoPO 4 , Prussian blue-based materials and those with the general formula X p M’ q (PO 4) r O x Y 3-x It can contain one or more of the materials that are. General formula X p M’ q (PO 4 ) r O x Y 3-x where 0 < p ≤ 4, 0 < q ≤ 2, 1 ≤ r ≤ 3, 0 ≤ x ≤ 2, X is H + , Li + , Na + , K + and NH 4 + and contains one or more selected from, M’ is a transition metal cation and optionally contains one or more selected from V, Ti, Mn, Fe, Co, Ni, Cu and Zn, Y is a halogen anion and optionally contains one or more selected from F, Cl and Br.

[0182] In the present application, the modified compound of each of the above positive electrode active materials can perform doping modification and / or surface coating modification on the positive electrode active material.

[0183] [Electrolyte] The present application does not particularly limit the type of the electrolyte, and it can be selected according to actual needs. For example, the electrolyte can be selected from at least one of a solid electrolyte and a liquid electrolyte (i.e., an electrolytic solution).

[0184] In some embodiments, the electrolyte uses an electrolytic solution, and the electrolytic solution contains an electrolyte salt and a solvent.

[0185] The type of the electrolyte salt is not specifically limited and can be selected according to actual needs.

[0186] When the secondary battery of the present application is a lithium ion battery, for example, the electrolyte salt is lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), lithium perchlorate (LiClO 4 ), lithium hexafluoroarsenate (LiAsF 6) Lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium trifluoromethanesulfonate (LiTFS), lithium difluorooxalate borate (LiDFOB), lithium bis(oxalate)borate (LiBOB), lithium difluorophosphate (LiPO 2 F 2 ) can include one or more of lithium difluorooxalate phosphate (LiDFOP) and lithium tetrafluorooxalate phosphate (LiTFOP).

[0187] When the secondary battery of the present application is a sodium-ion secondary battery, the electrolyte salt is sodium hexafluorophosphate (NaPF 6 ), sodium tetrafluoroborate (NaBF 4 ), sodium perchlorate (NaClO 4 ), sodium hexafluoroarsenate (NaAsF 6 ), sodium bis(fluorosulfonyl)imide (NaFSI), sodium bis(trifluoromethanesulfonyl)imide (NaTFSI), sodium trifluoromethanesulfonate (NaTFS), sodium difluorooxalate borate (NaDFOB), sodium bis(oxalate)borate (NaBOB), sodium difluorophosphate (NaPO 2 F 2 ) can include one or more of sodium difluorooxalate phosphate (NaDFOP) and sodium tetrafluorooxalate phosphate (NaTFOP).

[0188] The type of the solvent is not particularly limited and can be selected according to actual needs. In some embodiments, by way of example, the solvent can include one or more of ethylene carbonate (EC), propylene carbonate (PC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), butylene carbonate (BC), fluoroethylene carbonate (FEC), methyl formate (MF), methyl acetate (MA), ethyl acetate (EA), propyl acetate (PA), methyl propionate (MP), ethyl propionate (EP), propyl propionate (PP), methyl butyrate (MB), ethyl butyrate (EB), 1,4-butyrolactone (GBL), sulfolane (SF), methylsulfonylmethane (MSM), ethyl methanesulfonate (EMS), and diethyl sulfone (ESE).

[0189] In some embodiments, the electrolyte further selectively includes additives. For example, the additives may include a negative electrode film forming additive, may also include a positive electrode film forming additive, and further may include additives that can improve specific performance of the battery, such as additives that improve overcharge characteristics of the battery, additives that improve high temperature characteristics of the battery, additives that improve low temperature output characteristics of the battery, and the like.

[0190] [Separator] In a secondary battery using an electrolyte or a secondary battery using a solid electrolyte, it further includes a separator. The separator is installed between the positive electrode sheet and the negative electrode sheet and serves to isolate. The present application does not particularly limit the type of the separator, and any known porous structure separator having good chemical stability and mechanical stability can be selected.

[0191] In some embodiments, the material of the separator can include one or more of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different.

[0192] [Manufacturing method] The manufacturing method of the secondary battery of the present application is a known one. In some embodiments, a secondary battery can be formed by assembling a positive electrode sheet, a separator, a negative electrode sheet, and an electrolyte. As an example, an electrode assembly is formed from a positive electrode sheet, a separator, and a negative electrode sheet through a winding process and / or a lamination process, and the electrode assembly is placed in an exterior material, dried, and then an electrolyte is injected, and a battery cell can be obtained through processes such as vacuum encapsulation, standing, formation, and shaping. A plurality of battery cells can further be connected in series or in parallel or in series-parallel to form a battery module. A plurality of battery modules can further be connected in series or in parallel or in series-parallel to form a battery pack. In some embodiments, a plurality of battery cells can further directly form a battery pack.

[0193] Power consumption device According to the fourth aspect of the embodiment of the present application, a power consumption device including the secondary battery of the present application is provided. The secondary battery may be used as a power source of the power consumption device or as an energy storage element of the power consumption device. The power consumption device may be a mobile device (such as a mobile phone, a tablet computer, a notebook computer, etc.), an electric vehicle (such as a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, etc.), a train, a ship, a satellite, an energy storage system, etc., but is not limited thereto.

[0194] The power consumption device can select a specific type of secondary battery, such as a battery cell, a battery module, or a battery pack, according to its usage conditions.

[0195] FIG. 6 is a schematic diagram of a power consumption device as an example. The power consumption device is an all-electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or the like. In order to meet the requirements of high output and high energy density of the power consumption device, a battery pack or a battery module can be used as a power source.

[0196] Another example of a power consumption device may be a mobile phone, a tablet computer, a notebook computer, or the like. The power consumption device is generally required to be lightweight and thin, and a battery cell can be used as a power source.

[0197] Examples The following examples describe the content disclosed in the present application in more detail. However, various modifications and changes made within the scope of the content disclosed in the present application will be obvious to those skilled in the art. Therefore, these examples are merely illustrative. Unless otherwise specified, all values of parts, percentages, and ratios reported in the following examples are based on mass, and all reagents used in the examples are either commercially available or synthesized according to conventional methods and can be used directly without treatment. All devices used in the examples are commercially available.

[0198] Example 1 Commercially available coconut shells were ground in a jet mill until the volume-based particle size distribution D50 was 6.8 ± 0.5 μm and D90 was 13.7 ± 0.5 μm. Then, they were washed with a 3 mol / L aqueous perchloric acid solution at 60 °C for 12 h, followed by washing with deionized water until neutral, further washed with a 3 mol / L aqueous NaOH solution at 95 °C for 24 h, and then washed with deionized water until neutral. Subsequently, they were dried by blowing air to remove moisture. The dried powder was placed in a firing furnace, and under a nitrogen gas atmosphere and a furnace pressure of -5 kPa, the temperature was raised to 400 °C at a rate of 30 °C / min and then held for 10 h. Then, under a nitrogen gas atmosphere, the furnace pressure was -5 kPa, and the packing density was 0.3 g / cm 3Under the conditions, the temperature was raised to 1400 °C at a rate of 5 °C / min and then held for 10 h, and after completion, a carbonaceous material was obtained.

[0199] Referring to GB / T 21650.2-2008, at 0 °C, CO 2 was used to conduct an adsorption test on the carbonaceous material, and the relative pressure P / P 0 was between 10 -8 and 0.029 for the total CO 2 adsorption amount A and adsorption time B were recorded. P represents the test pressure of CO 2 , and P 0 represents the saturated vapor pressure of CO 2 at 0 °C. The test apparatus can use the ASAP 2460 type surface area and pore size analyzer of Micromeritics, USA.

[0200] Using the immersion volume replacement method based on Archimedes' principle, the true density of the carbonaceous material was tested with n-butanol as the medium.

[0201] Examples 2-16 and Comparative Examples 1-7 The manufacturing method of the carbonaceous material is the same as that in Example 1, and the difference is that the manufacturing process parameters of the carbonaceous material are adjusted, specifically as shown in Table 1.

[0202] Comparative Example 8 Commercially available coconut shells were ground with a jet mill until the volume-based particle size distribution D50 was 6.8 ± 0.5 μm and D90 was 13.7 ± 0.5 μm. Then, they were washed with a 3 mol / L aqueous perchloric acid solution at 60 °C for 12 h, and then washed with deionized water until neutral, and then dried by blowing to remove moisture. The dried powder was placed in a firing furnace, and under a nitrogen gas atmosphere and a furnace pressure of -5 kPa, the temperature was raised to 400 °C at a rate of 30 °C / min and then held for 10 h. Then, under a nitrogen gas atmosphere, a furnace pressure of -5 kPa and a packing density of 0.3 g / cm 3 under the conditions, the temperature was raised to 1400 °C at a rate of 5 °C / min and then held for 10 h, and after completion, a carbonaceous material was obtained.

[0203] Comparative Example 9 Commercially available coconut shells are ground with a jet mill until the volume-based particle size distribution has D50 of 6.8 ± 0.5 μm and D90 of 13.7 ± 0.5 μm. Then, they are washed with a 3 mol / L aqueous NaOH solution at 95 °C for 24 h, further washed with deionized water until neutral, and then dried by blowing air to remove moisture. The dried powder is placed in a firing furnace, and under a nitrogen gas atmosphere and a furnace pressure of -5 kPa, it is heated to 400 °C at a rate of 30 °C / min and then held for 10 h. Then, under a nitrogen gas atmosphere, a furnace pressure of -5 kPa, and a packing density of 0.3 g / cm 3 under the conditions of, it is heated to 1400 °C at a rate of 5 °C / min and then held for 10 h, and after completion, a carbonaceous material is obtained.

[0204] Comparative Example 10 Commercially available coconut shells are ground with a jet mill until the volume-based particle size distribution has D50 of 6.8 ± 0.5 μm and D90 of 13.7 ± 0.5 μm. Then, the powder is placed in a firing furnace, and under a nitrogen gas atmosphere and a furnace pressure of -5 kPa, it is heated to 400 °C at a rate of 30 °C / min and then held for 10 h. Then, under a nitrogen gas atmosphere, a furnace pressure of -5 kPa, and a packing density of 0.3 g / cm 3 under the conditions of, it is heated to 1400 °C at a rate of 5 °C / min and then held for 10 h, and after completion, a carbonaceous material is obtained.

[0205] Comparative Example 11 Commercially available coconut shells are ground with a jet mill until the volume-based particle size distribution has D50 of 6.8 ± 0.5 μm and D90 of 13.7 ± 0.5 μm. Then, the powder is placed in a firing furnace, and under a nitrogen gas atmosphere and a furnace pressure of -5 kPa, it is heated to 400 °C at a rate of 30 °C / min and then held for 10 h. Then, under a nitrogen gas atmosphere, a furnace pressure of -5 kPa, and a packing density of 0.3 g / cm 3 under the conditions of, it is heated to 1400 °C at a rate of 5 °C / min and then held for 10 h. Then, it is washed with a 3 mol / L perchloric acid aqueous solution at 60 °C for 12 h, further washed with deionized water until neutral, and finally dried by blowing air to remove moisture to obtain a carbonaceous material.

[0206] Comparative Example 12 The commercially available coconut shells were washed with 3 mol / L perchloric acid aqueous solution at 60 °C for 12 h, then washed with deionized water until neutral, further washed with 3 mol / L NaOH aqueous solution at 95 °C for 24 h, and further washed with deionized water until neutral. Then, they were dried by blowing air to remove moisture, and further pulverized with a jet mill until the volume-based particle size distribution D50 was 6.8 ± 0.5 μm and D90 was 13.7 ± 0.5 μm. The obtained powder was placed in a firing furnace, and under a nitrogen gas atmosphere and a furnace pressure of -5 kPa, the temperature was raised to 400 °C at a rate of 30 °C / min and then held for 10 h. Then, under a nitrogen gas atmosphere, a furnace pressure of -5 kPa, and a packing density of 0.3 g / cm 3 under the conditions of, the temperature was raised to 1400 °C at a rate of 5 °C / min and then held for 10 h. After completion, a carbonaceous material was obtained.

[0207] Comparative Example 13 The commercially available coconut shells were pulverized with a jet mill until the volume-based particle size distribution D50 was 6.8 ± 0.5 μm and D90 was 13.7 ± 0.5 μm. Then, they were washed with 3 mol / L perchloric acid aqueous solution at 60 °C for 12 h, then washed with deionized water until neutral, further washed with 3 mol / L NaOH aqueous solution at 95 °C for 24 h, and further washed with deionized water until neutral. Then, they were dried by blowing air to remove moisture. The dried powder was placed in a firing furnace, and under a nitrogen gas atmosphere, a furnace pressure of -5 kPa, and a packing density of 0.3 g / cm 3 under the conditions of, the temperature was raised to 1400 °C at a rate of 5 °C / min and then held for 10 h. After completion, a carbonaceous material was obtained.

[0208] Performance Test The carbonaceous materials produced in each of the examples and comparative examples, styrene-butadiene rubber (SBR) as a binder, sodium carboxymethyl cellulose (CMC-Na) as a thickener, and carbon black as a conductive agent were sufficiently stirred and mixed in an appropriate amount of deionized water with a mass ratio of 96.2:1.8:1.2:0.8 to form a uniform negative electrode paste. The negative electrode paste was uniformly coated on the surface of the copper foil of the negative electrode current collector, dried in an oven, and then prepared for use. After mixing ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) in a volume ratio of 1:1:1 to obtain an organic solvent, NaPF 6 was dissolved in the above organic solvent to prepare an electrolyte solution with a concentration of 1 mol / L. Then, using a metal sodium sheet as a counter electrode and a polyethylene (PE) film as a separator, a CR2430 type button battery was assembled in an argon-protected glove box.

[0209] At 25°C, first, the button batteries produced in each of the examples and comparative examples were discharged at a constant current density of 10 mA / g to 0 V, and the initial discharge capacity of the button battery was recorded. Then, they were charged at a constant current density of 10 mA / g to 2.0 V, and the initial charge capacity of the button battery was recorded.

[0210] The reversible specific capacity (mAh / g) of the carbonaceous material = the initial charge capacity of the button battery / the mass of the carbonaceous material.

[0211] The initial Coulombic efficiency (%) of the carbonaceous material = the initial charge capacity of the button battery / the initial discharge capacity of the button battery × 100%.

[0212] As can be comprehensively understood from the test results in Table 1, in the CO 2 adsorption test, at 0°C, when the relative pressure P / P 0 is between 10 -8 and 0.029, and the total CO 2 adsorption amount is A and the CO 2 adsorption time is B, then A / B ≧ 1.7 cm 3 / (g×h) STP is satisfied, and selectively ≧ 3.0 cm 3 / (g×h) STP, and further ≧ 8.0 cm3 It may be / (g×h)STP, and the carbonaceous material can have high capacity and initial Coulomb efficiency.

[0213] CO of the carbonaceous materials produced in Comparative Examples 1 to 13 2 In the CO adsorption test, at 0 °C, the relative pressure P / P 0 is from 10 -8 to 0.029, the total CO adsorption amount is designated as A, and when the CO adsorption time is designated as B, all of them do not satisfy A / B≧1.7 cm 2 / (g×h)STP, and none of the carbonaceous materials can have high capacity and initial Coulomb efficiency. 2 / (g×h)STP, and none of the carbonaceous materials can have high capacity and initial Coulomb efficiency. 3 / (g×h)STP, and none of the carbonaceous materials can have high capacity and initial Coulomb efficiency.

[0214] Figures 7 and 8 are graphs of the CO adsorption test of the carbonaceous material produced in Example 1. Figures 9 and 10 are graphs of the CO adsorption test of the carbonaceous material produced in Comparative Example 1. As comprehensively understood from the test results in Table 1, compared with Comparative Example 1, the capacity and initial Coulomb efficiency of the carbonaceous material produced in Example 1 are significantly improved. This is considered to be because the active ion storage space of the carbonaceous material produced in Example 1 is large and the space utilization rate is high, so that the insertion, storage and desorption of active ions are easy. 2 adsorption test. Figures 9 and 10 are graphs of the CO adsorption test of the carbonaceous material produced in Comparative Example 1. As comprehensively understood from the test results in Table 1, compared with Comparative Example 1, the capacity and initial Coulomb efficiency of the carbonaceous material produced in Example 1 are significantly improved. This is considered to be because the active ion storage space of the carbonaceous material produced in Example 1 is large and the space utilization rate is high, so that the insertion, storage and desorption of active ions are easy. 2 adsorption test. As comprehensively understood from the test results in Table 1, compared with Comparative Example 1, the capacity and initial Coulomb efficiency of the carbonaceous material produced in Example 1 are significantly improved. This is considered to be because the active ion storage space of the carbonaceous material produced in Example 1 is large and the space utilization rate is high, so that the insertion, storage and desorption of active ions are easy.

[0215] As comprehensively understood from the test results of Examples 1 - 16, when the CO adsorption time B further satisfies B≧5 h and selectively ≧7 h, the carbonaceous material can have higher capacity and initial Coulomb efficiency. 2 As comprehensively understood from the test results of Examples 1 - 16, when the CO adsorption time B further satisfies B≧5 h and selectively ≧7 h, the carbonaceous material can have higher capacity and initial Coulomb efficiency.

[0216] Note that the present application is not limited to the above embodiments. The above embodiments are merely illustrative, and any embodiments that have a configuration substantially identical to the technical idea and exhibit similar effects within the scope of the technical solution of the present application are included in the technical scope of the present application. Also, within the scope not departing from the gist of the present application, various modifications that can be conceived by those skilled in the art added to the embodiments, as well as other forms constructed by combining some of the components in the embodiments, are also included in the scope of the present application.

[0217]

Table 1

Claims

1. CO ２ In the adsorption test, at 0 °C, the relative pressure P / P ０ is between 10 －８ and 0.029 for CO ２ If the total adsorption amount is A and the adsorption time is B, then A / B ≥ 1.7 cm ３ / (g×h) STP is satisfied, where STP is the standard state, P is the test pressure of CO ２ and P ０ is the saturated vapor pressure of CO ２ at 0 °C, a carbonaceous material.

2. 1.7 cm ３ / (g×h) STP ≤ A / B ≤ 20 cm ３ / (g×h) STP, and optionally, 3.0 cm ３ / (g×h) STP ≤ A / B ≤ 20 cm ３ / (g×h) STP, the carbonaceous material according to claim 1

3. The carbonaceous material according to claim 1 or 2, wherein B ≥ 5h, and optionally, 5h ≤ B ≤ 10h.

4. A ≥ 10 cm ３ / g STP, and optionally, 15 cm ３ / g STP ≤ A ≤ 200 cm ３ / g STP, the carbonaceous material according to any one of claims 1 to 3.

5. The true density ρ is ≤ 1.45 g / cm ３ and selectively 1.0 g / cm ３ to 1.45 g / cm ３ The carbonaceous material according to any one of claims 1 to 4, wherein the carbonaceous material is such that

6. The carbonaceous material according to any one of claims 1 to 5, comprising a plurality of nanopore structures, and optionally, comprising a plurality of pore structures with a pore diameter of 10 nm or less.

7. In the Raman spectrum, I ｄ / I ｇ is 0.90 to 1.25, selectively 1.05 to 1.15, and I ｄ represents the d-band peak intensity of the Raman shift in the range of 1350 ± 50 cm －１ , and I ｇ represents the g-band peak intensity of the Raman shift in the range of 1580 ± 50 cm －１ , and / or The interlayer distance of the (002) crystal plane is ≥ 0.37 nm, and optionally 0.37 nm to 0.42 nm, and / or In the X-ray diffraction spectrum, the value of 2θ corresponding to the (002) crystal plane peak is between 22° and 24°. The carbonaceous material according to any one of claims 1 to 6.

8. The volume-based particle size distribution Dv50 is 3 μm to 15 μm, and optionally 4 μm to 6 μm for condition (1), and The volume-based particle size distribution Dv90 is 8 μm to 30 μm, and optionally 9 μm to 12 μm for condition (2). The specific surface area is 1 m ２ / g to 10 m ２ / g, and the condition (3) where it is selectively 1 m ２ / g to 5 m ２ / g, and The green density under a 50,000 N applied force is 0.90 g / cm ３ to 1.05 g / cm ３ and selectively 0.93 g / cm ３ to 1.02 g / cm ３ Condition (4), and The tap density is 0.80 g / cm ３ to 0.95 g / cm ３ and selectively satisfies at least one of the conditions (5) of 0.85 g / cm ３ to 0.9 g / cm ３ The carbonaceous material according to any one of claims 1 to 7.

9. Step S10 of providing a raw material which is an organic carbon source; Step S20 of pulverizing the raw material; Step S30 of performing a washing and impurity removal treatment on the pulverized raw material obtained in step S20 to remove impurities. The washing and impurity removal treatment process includes at least an acidic solution washing step and an alkaline solution washing step; Step S40 of placing the washed and impurity-removed raw material obtained in step S30 in a firing furnace, heating it to a first temperature T1 at a first rate of ≥ 20 °C / min under a condition that the furnace pressure is ≤ -2 kPa in a protective gas atmosphere, further holding it at the first temperature T1 for a first time t1, and obtaining pre-carbonized carbon after completion. Low-temperature preliminary carbonization treatment step; Place the pre-carbonized carbon obtained in step S40 in a firing furnace, and under a protective gas atmosphere, with the furnace internal pressure ≤ -2 kPa and the packing density ≤ 0.6 g / cm ３ Under the conditions of, raise the temperature to the second temperature T2 at the second rate, and further perform a heat retention treatment at the second temperature T2 for the second time t2. After completion, a high-temperature carbonization treatment step S50 for obtaining a carbonaceous material is included, The carbonaceous material is CO ２ In the adsorption test, at 0 °C, the relative pressure P / P ０ is between 10 －８ and 0.029, and the total amount of CO ２ adsorbed is designated as A, and the adsorption time is designated as B. In this case, the carbonaceous material satisfies A / B ≧ 1.7 cm ３ / (g×h) STP, where STP is the standard state, P represents the test pressure of CO ２ , and P ０ represents the saturated vapor pressure of CO ２ at 0 °C. A method for producing a carbonaceous material.

10. In step S10, the organic carbon source includes one or more of biomass materials and thermoplastic resin materials. Optionally, the biomass material includes one or more of energy crops and biomass waste. Optionally, the thermoplastic resin material includes one or more of phenolic resin, acrylic resin, polyvinyl chloride, polycarbonate, epoxy resin, polyoxymethylene, coumarone resin, and petroleum resin. The method according to claim 9.

11. In step S30, the cleaning and impurity removal process includes, in order, the steps of acidic solution cleaning, water cleaning, alkaline solution cleaning, water cleaning, and drying, or, in step S30, the cleaning and impurity removal process includes, in order, the steps of alkaline solution cleaning, water cleaning, acidic solution cleaning, water cleaning, and drying. The method according to claim 9 or 10.

12. In step S30, the acidic solution is H ＋ The concentration is 0.1 mol / L to 6 mol / L, and selectively 1 mol / L to 6 mol / L under condition (1), and The cleaning temperature is 10°C to 95°C, selectively 30°C to 95°C, condition (2), and The cleaning time is 1 h to 24 h, selectively 10 h to 24 h, condition (3), and The solute contains one or more of hydrochloric acid, nitric acid, sulfuric acid, and perchloric acid, and the solvent is water, satisfying at least one of the conditions (4). The method according to any one of claims 9 to 11.

13. In step S30, the alkaline solution is OH － The concentration is 0.1 mol / L to 6 mol / L, and the condition (1) that it is selectively 1 mol / L to 6 mol / L, and The cleaning temperature is 10°C to 95°C, selectively 30°C to 95°C, condition (2), and The cleaning time is 1 h to 24 h, selectively 10 h to 24 h, condition (3), and The solute contains NaOH, KOH, or a combination thereof, and the solvent is water, satisfying at least one of the conditions (4). The method according to any one of claims 9 to 12.

14. In step S40, the temperature T1 is 300°C to 600°C, selectively 400°C to 500°C, and / or In step S40, the time t1 is 1 h to 24 h, selectively 6 h to 12 h, and / or In step S40, the heating rate is 20°C / min to 35°C / min, selectively 25°C / min to 30°C / min, and / or In step S40, the protective gas contains nitrogen gas, argon gas, helium gas, or a combination thereof, and / or In step S40, the furnace internal pressure is from -5 kPa to -2 kPa, selectively from -4.5 kPa to -3 kPa. The method according to any one of claims 9 to 13.

15. In step S50, the temperature T2 is 1000°C to 1600°C, selectively 1200°C to 1400°C, and / or In step S50, the time t2 is 1 h to 24 h, selectively 6 h to 12 h, and / or In step S50, the heating rate is 1 °C / min to 10 °C / min, optionally 3 °C / min to 5 °C / min, and / or In step S50, the protective gas includes nitrogen gas, argon gas, helium gas, or a combination thereof, and / or In step S50, the pressure inside the furnace is from -5 kPa to -2 kPa, optionally from -4.5 kPa to -3 kPa, the method according to any one of claims 9 to 14.

16. A secondary battery including a negative electrode sheet containing a carbonaceous material according to any one of claims 1 to 8 or a carbonaceous material produced by the method according to any one of claims 9 to 15.

17. An electric power consuming device including the secondary battery according to claim 16.

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