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EP-4738471-A1 - NEGATIVE ELECTRODE MATERIAL AND NEGATIVE ELECTRODE USING SAME, ELECTROCHEMICAL DEVICE, AND ELECTRONIC DEVICE

EP4738471A1EP 4738471 A1EP4738471 A1EP 4738471A1EP-4738471-A1

Abstract

This application relates to a negative electrode material, a negative electrode using the material, an electrochemical apparatus, and an electronic apparatus. Specifically, this application provides a negative electrode material, including graphite, where the negative electrode material has an I-order lithium intercalation plateau potential P1 of 30 mV to 75 mV and an II-order lithium intercalation plateau potential P2 of 90 mV to 110 m V The use of the negative electrode material of this application can significantly improve the cycling performance of the electrochemical apparatus using the negative electrode material under high voltage and high temperature, enhance the gram capacity of the negative electrode material, while maintaining the initial efficiency of the negative electrode material.

Inventors

  • CHEN, YUSHENG
  • DONG, JIALI

Assignees

  • Ningde Amperex Technology Limited

Dates

Publication Date
20260506
Application Date
20230630

Claims (13)

  1. A negative electrode material, comprising graphite, wherein an I-order lithium intercalation plateau potential P1 of the negative electrode material is 30 mV to 75 mV, and an II-order lithium intercalation plateau potential P2 is 90 mV to 110 mV.
  2. The negative electrode material according to claim 1, wherein a specific surface area of the negative electrode material is S m 2 /g, and S ranges from 2 to 8.
  3. The negative electrode material according to claim 2, wherein the negative electrode material comprises pores with a pore size of not greater than 5 nm, a specific surface area of the pores is S1 m 2 /g, and a ratio of S1 to S ranges from 0.05 to 0.3.
  4. The negative electrode material according to claim 3, wherein the negative electrode material satisfies at least one of the following: (1) S ranges from 4 to 7; (2) S1 ranges from 0.1 to 1.5; or (3) the ratio of S1 to S ranges from 0.15 to 0.3.
  5. The negative electrode material according to claim 1, wherein the I-order lithium intercalation plateau potential P1 is 30 mV to 60 mV, and the II-order lithium intercalation plateau potential P2 is 90 mV to 100 mV.
  6. The negative electrode material according to claim 2, wherein in a Raman testing, a peak intensity of the negative electrode material at 1350 cm -1 is D, a peak intensity of the negative electrode material at 1580 cm -1 is G, a ratio of D to G is R, and 0.025 ≤ R/S ≤ 0.25.
  7. The negative electrode material according to claim 6, wherein the negative electrode material satisfies at least one of the following: (1) 0.1 ≤ R ≤ 0.7 ; or (2) 0.05 ≤ R / S ≤ 0.15 .
  8. The negative electrode material according to claim 6, wherein 0.2 ≤ R ≤ 0.55.
  9. The negative electrode material according to claim 1, wherein the negative electrode material satisfies at least one of the following: (1) a thermogravimetric decomposition temperature of the negative electrode material ranges from 650°C to 850°C; or (2) a powder compacted density of the negative electrode material is 1.90 g/cm 3 to 2.10 g/cm 3 , and a powder rebound rate is 15% to 35%.
  10. A negative electrode, comprising the negative electrode material according to any one of claims 1 to 9, a dispersant, and a binder.
  11. The negative electrode according to claim 10, wherein a porosity of the negative electrode is 17% to 35%.
  12. An electrochemical apparatus, comprising a positive electrode, a separator, an electrolyte, and the negative electrode according to claim 10 or 11.
  13. An electronic apparatus, comprising the electrochemical apparatus according to claim 12.

Description

TECHNICAL FIELD This application relates to the field of energy storage, and specifically, to a negative electrode material, a negative electrode using the negative electrode material, an electrochemical apparatus, and an electronic apparatus. BACKGROUND With the widespread application of electrochemical apparatuses (for example, lithium-ion batteries) in electronic products such as mobile phones, laptop computers, tablet computers, Bluetooth headsets, and wearable watches, the performance requirements for these apparatuses are increasingly stringent. The cycle life and energy density of lithium batteries are most critical performance indicators, significantly effecting the service life and usage duration of electronic products. Increasing voltage helps to improve energy density, but under high-voltage systems, the cycling performance of lithium-ion batteries, particularly at high temperatures, tends to deteriorate. In view of this, it is indeed necessary to provide an improved negative electrode material that offers enhanced gram capacity, significantly improves the cycling performance of electrochemical apparatuses under high temperature and high voltage, while maintaining the initial efficiency of the negative electrode material. SUMMARY This application provides a negative electrode material in an attempt to solve at least one problem existing in the related art to at least some extent. According to a first aspect of this application, this application provides a negative electrode material, including graphite, where the negative electrode material has an I-order lithium intercalation plateau potential P1 of 30 mV to 75 mV, and an II-order lithium intercalation plateau potential P2 of 90 mV to 110 mV. According to an embodiment of this application, the I-order lithium intercalation plateau potential P1 of the negative electrode material is 30 mV to 60 mV, and the II-order lithium intercalation plateau potential P2 is 90 mV to 100 mV. According to an embodiment of this application, a specific surface area of the negative electrode material is S m2/g, where S ranges from 2 to 8. According to an embodiment of this application, S ranges from 4 to 7. According to an embodiment of this application, the negative electrode material includes pores with a pore size of not greater than 5 nm, a specific surface area of the pores is S1 m2/g, and a ratio of S1 to S ranges from 0.05 to 0.3. According to an embodiment of this application, the ratio of S1 to S ranges from 0.15 to 0.3. According to an embodiment of this application, S1 ranges from 0.1 to 1.5. According to an embodiment of this application, in a Raman testing, a peak intensity of the negative electrode material at 1350 cm-1 is D, a peak intensity of the negative electrode material at 1580 cm-1 is G, a ratio of D to G is R, and 0.025 ≤ R/S ≤ 0.25. According to an embodiment of this application, 0.05 ≤ R/S ≤ 0.15. According to an embodiment of this application, 0.1 ≤ R ≤ 0.7. According to an embodiment of this application, 0.2 ≤ R ≤ 0.55. According to an embodiment of this application, a thermogravimetric decomposition temperature of the negative electrode material ranges from 650°C to 850°C. According to an embodiment of this application, a powder compacted density of the negative electrode material is 1.90 g/cm3 to 2.10 g/cm3, and a powder rebound rate is 15% to 35%. According to another aspect of this application, this application provides a negative electrode, including the negative electrode material of this application, a dispersant, and a binder. According to an embodiment of this application, a porosity of the negative electrode is 17% to 35%. According to another aspect of this application, this application provides an electrochemical apparatus, including a positive electrode, a separator, an electrolyte, and the negative electrode according to this application. According to another aspect of this application, an electronic apparatus is provided, including the electrochemical apparatus according to this application. This application, by lowering a positive electrode potential to protect the stability of a positive electrode structure in a high-voltage system, enhances the gram capacity of the negative electrode material, improves the cycling performance of the electrochemical apparatus under high temperature and high voltage, while maintaining the initial efficiency of the negative electrode material. Additional aspects and advantages of this application are partially described and presented in subsequent descriptions, or explained by implementation of some embodiments of this application. BRIEF DESCRIPTION OF THE DRAWINGS To describe embodiments of this application, the following briefly describes the accompanying drawings required for describing some embodiments of this application or the prior art. Apparently, the accompanying drawings described below are merely some embodiments of this application. Persons skilled in the art can still derive dra