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CN-121990555-A - Carbonaceous material, method for producing same, secondary battery and electricity-using device each comprising same

CN121990555ACN 121990555 ACN121990555 ACN 121990555ACN-121990555-A

Abstract

A carbonaceous material and a preparation method thereof, and a secondary battery and an electric device containing the same, wherein the adsorption rate v of the carbonaceous material is 0.015-0.050 when the carbonaceous material is subjected to adsorption test by adopting water vapor under the conditions of 25 ℃ and 40% RH constant temperature and humidity, the water vapor adsorption test is carried out under the conditions that the carbonaceous material with the mass of m 1 is placed in a container in a constant temperature and humidity box with the temperature of 25 ℃ and 40% RH, the water vapor adsorption mass m 2 and the water vapor adsorption time t when the carbonaceous material adsorbs water vapor to reach equilibrium are recorded, the measurement unit of the water vapor adsorption rate v=m 2 /(m 1 ×t),m 1 is g, the measurement unit of m 2 is g, and the measurement unit of t is h. The carbonaceous material can give consideration to higher gram capacity, higher first coulombic efficiency and higher structural stability.

Inventors

  • MA YU
  • ZHANG XINXIN
  • CHEN XIAOXIA
  • OUYANG CHUYING
  • LIN WENGUANG
  • CHEN SHANGDONG
  • CHENG WEIMING
  • ZHENG XIAOJI

Assignees

  • 宁德时代新能源科技股份有限公司

Dates

Publication Date
20260508
Application Date
20221021

Claims (16)

  1. 1. A method for preparing a carbonaceous material, comprising the steps of: S10, providing a carbon source, wherein the carbon source is a cellulosic biomass material, and the ash content in the cellulosic biomass material is less than or equal to 5wt%; S20, low-temperature pre-carbonization treatment, namely heating the carbon source to a first temperature T1 at a first heating rate under the atmosphere of protective gas, and then preserving heat for a first time T1 to obtain a first intermediate product; S30, performing high-temperature carbonization treatment, namely heating the obtained first intermediate product to a second temperature T2 at a second heating rate in a protective gas atmosphere, and then performing heat preservation treatment for a second time T2 to obtain a carbonaceous material, wherein the adsorption rate v of the carbonaceous material in an adsorption test by adopting water vapor under the conditions of 25 ℃ and 40% RH constant temperature and humidity meets 0.015-v-0.050, and the water vapor adsorption test is performed under the conditions that the carbonaceous material with the mass of m 1 is placed in a container in a constant temperature and humidity box with the temperature of 25 ℃ and 40% RH, the water vapor adsorption mass m 2 and the water vapor adsorption time T when the adsorption water vapor of the carbonaceous material reaches balance are recorded, the measurement unit of the water vapor adsorption rate v=m 2 /(m 1 ×t),m 1 is g, the measurement unit of m 2 is g, and the measurement unit of T is h.
  2. 2. The method of claim 1, wherein the cellulosic biomass material has a cellulose content of greater than 0wt% and less than or equal to 100wt%.
  3. 3. The method according to claim 1 or 2, wherein, The cellulose content in the cellulose biomass material is more than or equal to 20wt% and less than 100deg.C, and/or, The ash content in the cellulosic biomass material is less than or equal to 2wt%.
  4. 4. A method according to claim 2 or 3, wherein, The hemicellulose content of the cellulosic biomass material is less than or equal to 70wt%, optionally less than or equal to 30wt%, and/or, The lignin content in the cellulosic biomass material is less than or equal to 60wt%, optionally 10wt% to 60wt%.
  5. 5. The method of any of claims 2-4, wherein the cellulosic biomass material comprises one or more of woody biomass material, optionally one or more of hardwood, softwood, and nut shells, more optionally one or more of pine, moso bamboo, and walnut shells.
  6. 6. The method according to any one of claims 1 to 5, wherein, The first heating rate is 1-10deg.C/min, optionally 1-3deg.C/min, and/or, The first temperature T1 is 150-1000 ℃, optionally 300-700 ℃, and/or, The first time t1 is 1h-20h, optionally 5h-20h.
  7. 7. The method according to any one of claims 1 to 6, wherein, The second heating rate is less than or equal to 10 ℃ per minute, alternatively 0.5 ℃ per minute to 10 ℃ per minute, and/or, The second temperature T2 is 1000-1600 ℃, optionally 1200-1500 ℃, and/or, The second time t2 is 1h-12h, optionally 3h-10h.
  8. 8. The method of any one of claims 1-7, wherein t1+t2 is 10h-30h.
  9. 9. The method according to any one of claims 1 to 8, wherein the method further comprises the steps of crushing the first intermediate product obtained in S20, washing and impurity removing the first intermediate product obtained in S20, or crushing the first intermediate product obtained in S20 before washing and impurity removing the first intermediate product obtained in S20 to obtain the first intermediate product with the ash content less than or equal to 0.01wt%, wherein the washing and impurity removing treatment process at least comprises an acidic solution washing step and an alkaline solution washing step.
  10. 10. The method according to claim 9, wherein the washing and impurity removal treatment process comprises the steps of washing with an acidic solution, washing with water, washing with an alkaline solution, washing with water and drying, or comprises the steps of washing with an alkaline solution, washing with water, washing with an acidic solution, washing with water and drying.
  11. 11. The method of claim 9 or 10, wherein the acidic solution satisfies at least one of the following conditions (1) to (4): (1) The concentration of H + in the acidic solution is 0.1moL/L-6moL/L, and can be 1moL/L-6moL/L; (2) The washing temperature of the acidic solution is 10-95 ℃, optionally 30-95 ℃; (3) The washing time of the acid solution is 1h-24h, and is optionally 10h-24h; (4) The solute of the acidic solution comprises one or more of hydrochloric acid, nitric acid, sulfuric acid and perchloric acid, and the solvent comprises water.
  12. 12. The method according to any one of claims 9-11, wherein the alkaline solution satisfies at least one of the following conditions (1) to (4): (1) The concentration of OH - in the alkaline solution is 0.1moL/L-6moL/L, optionally 1moL/L-6moL/L; (2) The washing temperature of the alkaline solution is 10-95 ℃, optionally 30-95 ℃; (3) The washing time of the alkaline solution is 1h-24h, and is optionally 10h-24h; (4) The solute of the alkaline solution comprises NaOH, KOH, or a combination thereof, and the solvent comprises water.
  13. 13. A carbonaceous material, wherein the carbonaceous material is prepared by the method of any one of claims 1-12.
  14. 14. A negative electrode tab, wherein the negative electrode tab comprises the carbonaceous material of claim 13.
  15. 15. A secondary battery comprising a negative electrode tab comprising the carbonaceous material of claim 13.
  16. 16. An electric device comprising the secondary battery according to claim 15.

Description

Carbonaceous material, method for producing same, secondary battery and electricity-using device each comprising same The application is based on the application of the application number 202280095632.3, the application date of 2022, 10 and 21, the application number of Ningde New energy science and technology Co., ltd, the application name of which is 'carbonaceous material and preparation method thereof, and secondary battery and electricity utilization device containing the carbonaceous material'. Technical Field The application belongs to the technical field of batteries, and particularly relates to a carbonaceous material, a preparation method thereof, a secondary battery containing the carbonaceous material and an electric device. Background In recent years, secondary batteries are widely used in energy storage power supply systems such as hydraulic power, thermal power, wind power and solar power stations, and in various fields such as electric tools, electric bicycles, electric motorcycles, electric automobiles, military equipment, aerospace, and the like. With the application and popularization of secondary batteries, energy density, service life and rate capability of the secondary batteries are receiving more and more attention. Graphite is the most commonly used negative electrode active material of a secondary battery, but the theoretical gram capacity of the graphite is only 372mAh/g, the energy density improving space is very limited, meanwhile, the interlayer spacing of the graphite is smaller, and the rate performance improvement is limited. Hard carbon is used as a novel negative electrode active material, and can realize rapid intercalation and deintercalation of active ions in the process of charging and discharging the secondary battery, so that the development prospect is very broad. However, the gram capacity and the first coulombic efficiency of hard carbon are low, and the improvement of the energy density, the service life and the rate capability of the secondary battery is limited. Disclosure of Invention The application aims to provide a carbonaceous material, a preparation method thereof, a secondary battery and an electric device containing the carbonaceous material, wherein the carbonaceous material can achieve higher gram capacity, higher first coulombic efficiency and higher structural stability, and the secondary battery can have high energy density, long service life and good multiplying power performance. The first aspect of the application provides a carbonaceous material, wherein the adsorption rate v of the carbonaceous material when adsorption test is carried out by adopting water vapor under the conditions of 25 ℃ and 40% RH constant temperature and humidity is 0.015-v-0.050, the water vapor adsorption test is carried out under the conditions that the carbonaceous material with the mass of m 1 is placed in a container in a constant temperature and humidity box with the temperature of 25 ℃ and 40% RH, the water vapor adsorption mass m 2 and the water vapor adsorption time t when the adsorption of the water vapor of the carbonaceous material reaches equilibrium are recorded, the measurement unit of the water vapor adsorption rate v=m 2/(m1×t),m1 is g, the measurement unit of m 2 is g, and the measurement unit of t is h. Compared with the currently commercialized carbonaceous material, the carbonaceous material provided by the application can achieve higher gram capacity, higher first coulombic efficiency and higher structural stability, and can enable the secondary battery to have high energy density, long service life and good multiplying power performance. Although the mechanism is not clear, the inventors of the present application speculate that one possible reason is that when the water vapor adsorption rate v is between 0.015 and 0.050, the carbonaceous material of the present application has high structural stability and a unique pore structure, and is capable of facilitating intercalation, storage and deintercalation of active ions, and further the carbonaceous material of the present application is capable of achieving both a higher gram capacity and first coulombic efficiency, and is capable of enabling a secondary battery to have a high energy density, a long service life and good rate performance at the same time. In any embodiment of the application, 0.020≤v≤0.050. Thereby being beneficial to further improving the gram capacity, the first coulombic efficiency and the structural stability of the carbonaceous material, and further improving the energy density, the service life and the multiplying power performance of the secondary battery. In any embodiment of the present application, the water vapor adsorption time t when the carbonaceous material adsorbs water vapor to reach equilibrium is 1h to 12h, optionally 4.5h to 7h. When the water vapor adsorption time when the adsorption water vapor of the carbonaceous material reaches the equilibrium meets the spe