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EP-4738463-A1 - SILICON-CARBON-CONTAINING ELECTRODE MATERIAL, METHOD OF MANUFACTURING THE SAME AND LITHIUM SECONDARY BATTERY INCLUDING THE SAME

EP4738463A1EP 4738463 A1EP4738463 A1EP 4738463A1EP-4738463-A1

Abstract

A silicon-carbon-containing electrode material according to embodiments of the present disclosure includes a porous carbon structure including pores and a silicon-containing coating layer formed on the porous carbon structure, wherein the peak intensity ratio of the Raman spectrum, expressed as a percentage and as defined by a predetermined equation, is 3% to 18%. Accordingly, the cycle life and capacity characteristics of a lithium secondary battery may be improved.

Inventors

  • CHUNG, DONG JAE
  • LA, YUN JI
  • KIM, NAK WON
  • PARK, EUN JUN
  • Moon, Joon Hyung
  • LEE, HYUN JI

Assignees

  • SK On Co., Ltd.
  • SK Innovation Co., Ltd.

Dates

Publication Date
20260506
Application Date
20251021

Claims (15)

  1. A silicon-carbon-containing electrode material comprising: a porous carbon structure including pores; and a silicon-containing coating layer formed on the porous carbon structure, wherein the peak intensity ratio of the Raman spectrum expressed as a percentage, as defined by Equation 1 below, is 3% to 18%: Peak intensity ratio of Raman spectrum % = I B / I A × 100 (in Equation 1, I A represents the maximum peak intensity at 2500 cm -1 to 3000 cm -1 when the wavenumber range of 2300 cm -1 to 3120 cm -1 of the Raman spectrum is used as the baseline, and I B represents the maximum peak intensity at 2080 cm -1 to 2120 cm -1 when the wavenumber range of 1850 cm -1 to 2200 cm -1 of the Raman spectrum is used as the baseline).
  2. The silicon-carbon-containing electrode material according to claim 1, wherein the peak intensity ratio of the Raman spectrum expressed as a percentage is 4% to 15%.
  3. The silicon-carbon-containing electrode material according to claim 1 or claim 2, wherein the peak intensity ratio of the Raman spectrum expressed as a percentage is 4.73% to 13.85%.
  4. The silicon-carbon-containing electrode material according to any one of claims 1 to 3, wherein the content of silicon based on the total weight of the electrode material is 38% by weight to 60% by weight.
  5. The silicon-carbon-containing electrode material according to any one of claims 1 to 4, wherein the content of silicon based on the total weight of the electrode material is 45% by weight to 55% by weight.
  6. The silicon-carbon-containing electrode material according to any one of claims 1 to 5, wherein the content of silicon based on the total weight of the electrode material is 35.9% by weight to 49.3% by weight.
  7. A method for manufacturing a silicon-carbon-containing electrode material, the method comprising: preparing a porous carbon structure including pores; supplying a silicon source gas onto the porous carbon structure in a reactor to form a silicon-containing coating layer on the porous carbon structure; and reducing the pressure within the reactor to a range of 1 Torr to 250 Torr to obtain a silicon-carbon-containing electrode material.
  8. The method according to claim 7, wherein the peak intensity ratio of the Raman spectrum, expressed as a percentage and as defined by Equation 1 below, measured from the silicon-carbon-containing electrode material, is 3% to 18%: Peak intensity ratio of Raman spectrum % = I B / I A × 100 (in Equation 1, I A represents the maximum peak intensity at 2500 cm -1 to 3000 cm -1 when the wavenumber range of 2300 cm -1 to 3120 cm -1 of the Raman spectrum is used as the baseline, and I B represents the maximum peak intensity at 2080 cm -1 to 2120 cm -1 when the wavenumber range of 1850 cm -1 to 2200 cm -1 of the Raman spectrum is used as the baseline).
  9. The method according to claim 7 or claim 8, wherein the supply of the silicon source gas is performed at a temperature of 300 °C to 600 °C.
  10. The method according to any one of claims 7 to 9, wherein the supply of the silicon source gas is performed for 2 to 8 hours.
  11. The method according to any one of claims 7 to 10, wherein the silicon source gas is a gas mixture of silane gas and a non-reactive gas.
  12. The method according to any one of claims 7 to 11, wherein the depressurization is performed at a temperature of 200 °C to 600 °C.
  13. The method according to any one of claims 7 to 12, wherein the depressurization is performed for 0.5 hours to 3.5 hours.
  14. The method according to any one of claims 7 to 13, wherein the depressurization is performed under a non-reactive gas atmosphere.
  15. A lithium secondary battery comprising: an anode including the silicon-carbon-containing electrode material according to any one of claims 1 to 6; and a cathode disposed opposite to the anode.

Description

BACKGROUND 1. Field of the Invention The disclosure of the present application relates to a silicon-carbon-containing electrode material, a method of manufacturing the same, and a lithium secondary battery including the silicon-carbon-containing electrode material. More specifically, the present disclosure relates to a silicon-carbon-containing electrode material including a porous carbon structure and a lithium secondary battery including the silicon-carbon-containing electrode material. 2. Description of the Related Art Secondary batteries are batteries that can be repeatedly charged and discharged. With the development of information and communication and display industries, they have been widely applied as power sources for portable electronic communication devices, such as camcorders, mobile phones, and laptop PCs. In addition, battery packs including secondary batteries have recently been developed and applied as power sources for eco-friendly vehicles, such as electric vehicles. Examples of secondary batteries may include a lithium secondary battery, a nickelcadmium battery, and a nickel-hydrogen battery. Among these, the lithium secondary batteries have a high operating voltage, a high energy density per unit weight, and are advantageous in terms of charging speed and weight reduction. For example, the lithium secondary battery may include: an electrode assembly including a cathode, an anode, and a separation membrane (separator); and an electrolyte in which the electrode assembly is impregnated. The lithium secondary battery may further include, for example, a pouch-type outer case in which the electrode assembly and the electrolyte are accommodated. To manufacture lithium secondary batteries with higher capacity and output, silicon and carbon may be composited and used as an anode material. For example, silicon may improve the capacity characteristics of the battery, and carbon may serve as a support for silicon. SUMMARY An object of the present disclosure is to provide a silicon-carbon-containing electrode material having improved cycle life and capacity characteristics. Another object of the present disclosure is to provide a method for manufacturing the silicon-carbon-containing electrode material. Still another object of the present disclosure is to provide a lithium secondary battery having improved cycle life and capacity characteristics. A silicon-carbon-containing electrode material according to exemplary embodiments includes: a porous carbon structure including pores; and a silicon-containing coating layer formed on the porous carbon structure. The peak intensity ratio of the Raman spectrum, expressed as a percentage and as defined by Equation 1 below, measured from the silicon-carbon-containing electrode material, may be 3% to 18%. PeakintensityratioofRamanspectrum%=IB/IA×100 In Equation 1, IA may represent the maximum peak intensity at 2500 cm-1 to 3000 cm-1 when the wavenumber range of 2300 cm-1 to 3120 cm-1 of the Raman spectrum is used as the baseline, and IB may represent the maximum peak intensity at 2080 cm-1 to 2120 cm-1 when the wavenumber range of 1850 cm-1 to 2200 cm-1 of the Raman spectrum is used as the baseline. In some embodiments, the peak intensity ratio of the Raman spectrum expressed as a percentage may be 4% to 15%. In some embodiments, the peak intensity ratio of the Raman spectrum expressed as a percentage may be 4.73% to 13.85%. In some embodiments, the content of silicon based on the total weight of the electrode material may be 38% by weight to 60% by weight. In some embodiments, the content of silicon based on the total weight of the electrode material may be 45% by weight to 55% by weight. In some embodiments, the content of silicon based on the total weight of the electrode material may be 35.9% by weight to 49.3% by weight. In a method for manufacturing a silicon-carbon-containing electrode material, a porous carbon structure including pores may be prepared. A silicon source gas may be supplied onto the porous carbon structure in a reactor to form a silicon-containing coating layer on the porous carbon structure. The pressure within the reactor may be reduced to a range of 1 Torr to 250 Torr to obtain a silicon-carbon-containing electrode material. In some embodiments, the peak intensity ratio of the Raman spectrum, expressed as a percentage and as defined by Equation 1 below, measured from the silicon-carbon-containing electrode material, may be 3% to 18%: PeakintensityratioofRamanspectrum%=IB/IA×100 In Equation 1, IA may represent the maximum peak intensity at 2500 cm-1 to 3000 cm-1 when the wavenumber range of 2300 cm-1 to 3120 cm-1 of the Raman spectrum is used as the baseline, and IB may represent the maximum peak intensity at 2080 cm-1 to 2120 cm-1 when the wavenumber range of 1850 cm-1 to 2200 cm-1 of the Raman spectrum is used as the baseline. In some embodiments, the supply of the silicon source gas may be performed at a temperature of 300 °C to 60