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US-12626959-B2 - Carbon-ceramic composites, electrode comprising the same and secondary battery comprising the electrode

US12626959B2US 12626959 B2US12626959 B2US 12626959B2US-12626959-B2

Abstract

The present disclosure relates to a ceramic-carbon composite including a ceramic shell surrounding a hollow portion; and a carbon coating layer surrounding the ceramic shell, wherein the hollow portion is in a vacuum state, an electrode including the ceramic-carbon composite, and a secondary battery including the electrode. The ceramic-carbon composite of the present disclosure has excellent thermal barrier effect and electrical conductivity, and thus, when used in the electrode, non-ideal heat transfer between an electrode active material and an electrode current collector is blocked to prevent a thermal runaway phenomenon, to have an effect that can significantly improve safety of the secondary battery.

Inventors

  • Chang Mook Hwang
  • Jong Hyeok Lee
  • Yoon Ji JO

Assignees

  • SK ON CO., LTD.

Dates

Publication Date
20260512
Application Date
20221223
Priority Date
20220407

Claims (17)

  1. 1 . A ceramic-carbon composite comprising: a ceramic shell surrounding a hollow portion; and a carbon coating layer surrounding the ceramic shell, wherein the hollow portion is in a vacuum state.
  2. 2 . The ceramic-carbon composite of claim 1 , wherein the ceramic shell comprises at least one selected from the group consisting of Al 2 O 3 , SiO 2 , ZrO 2 , and SiC.
  3. 3 . The ceramic-carbon composite of claim 1 , wherein the ceramic shell has an average thickness of 1 nm to 1 μm.
  4. 4 . The ceramic-carbon composite of claim 1 , wherein the carbon coating layer has an average thickness of 1 nm to 1 μm.
  5. 5 . The ceramic-carbon composite of claim 1 , wherein the ceramic-carbon composite has a diameter of 10 nm to 5 μm.
  6. 6 . The ceramic-carbon composite of claim 1 , wherein the ceramic-carbon composite has a compressive strength of 30 to 50 MPa.
  7. 7 . An electrode comprising: an electrode current collector; a first layer formed on at least one surface of the electrode current collector; and a second layer formed on the first layer and including an electrode mixture layer including an electrode active material, wherein the first layer includes a ceramic shell surrounding a hollow portion; and a carbon coating layer surrounding the ceramic shell, and wherein the hollow portion is in a vacuum state.
  8. 8 . The electrode of claim 7 , wherein the first layer further comprises a binder.
  9. 9 . The electrode of claim 8 , wherein the first layer comprises 90 to 99 wt % of the ceramic-carbon composite and 1 to 10 wt % of the binder.
  10. 10 . The electrode of claim 7 , wherein the first layer has a thickness of 1 to 10 μm.
  11. 11 . The electrode of claim 7 , wherein the electrode is a positive electrode or a negative electrode.
  12. 12 . The electrode of claim 7 , wherein the ceramic shell comprises at least one selected from the group consisting of Al 2 O 3 , SiO 2 , ZrO 2 , and SiC.
  13. 13 . The electrode of claim 7 , wherein the ceramic shell has an average thickness of 1 nm to 1 μm.
  14. 14 . The electrode of claim 7 , wherein carbon coating layer has an average thickness of 1 nm to 1 μm.
  15. 15 . The electrode of claim 7 , wherein ceramic-carbon composite has a diameter of 10 nm to 5 μm.
  16. 16 . The electrode of claim 7 , wherein ceramic-carbon composite has a compressive strength of 30 to 50 MPa.
  17. 17 . A secondary battery comprising the electrode according to claim 7 .

Description

CROSS-REFERENCE TO RELATED APPLICATION(S) This application claims benefit of priority to Korean Patent Application No. 10-2022-0043480 filed on Apr. 7, 2022 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. BACKGROUND 1. Field The present disclosure relates to a secondary battery having improved safety, and more particularly, a ceramic-carbon composite, a method for fabricating the same, an electrode including the same, and a secondary battery including the electrode. 2. Description of Related Art As a driving power source for mobile information terminals such as a mobile phone, a notebook computer, a smartphone, and the like, a lithium secondary battery having a high energy density and being easy to carry is mainly used. In addition, recent research has been actively conducted to use such a lithium secondary battery as a driving power source or a power storage power source for a hybrid vehicle or a battery-powered vehicle by using the characteristic of high energy density. A large number of secondary batteries may be electrically connected to increase capacity and output. One of the main research tasks in the lithium secondary battery is to improve safety of the secondary battery. In particular, when a thermal runaway phenomenon occurs due to heat generated in a decomposition reaction of an active material, excessive current may occur due to damage to a separator, while a short circuit between positive and negative electrodes, or an internal short circuit may also occur, which may cause fire or an explosion. In addition, in a medium-to-large device in which a plurality of lithium secondary batteries are electrically connected, such as an electric vehicle or the like, a thermal runaway phenomenon generated in a unit cell may affect adjacent unit cells, and accordingly, heat transfer to an entirety of a module or a pack may ensue. As such, since the thermal runaway phenomenon may inflict fatal damage to users, in addition to damage to the lithium secondary battery, it is necessary to develop a technology capable of improving safety of the lithium secondary battery. SUMMARY The present disclosure is provided to solve the above problems, and to prevent instantaneous heat transfer between an electrode active material and an electrode current collector, even when non-ideal heat is generated from the electrode active material, which is a trigger point of a thermal runaway phenomenon. To this end, as an embodiment, a ceramic-carbon composite, a method for fabricating the same, an electrode including the ceramic-carbon composite, and a secondary battery including the electrode are provided. According to an aspect of the present disclosure, a ceramic-carbon composite includes a ceramic shell surrounding a hollow portion; and a carbon coating layer surrounding the ceramic shell, wherein the hollow portion is in a vacuum state. The ceramic shell may include at least one selected from the group consisting of Al2O3, SiO2, ZrO2, and SiC. The ceramic shell may have an average thickness of 1 nm to 1 μm. The carbon coating layer may have an average thickness of 1 nm to 1 μm. The ceramic-carbon composite may have a diameter of 10 nm to 5 μm. The ceramic-carbon composite may have a compressive strength of 30 to 50 MPa. According to an aspect of the present disclosure, an electrode includes an electrode current collector; a first layer formed on at least one surface of the electrode current collector; and a second layer formed on the first layer and including an electrode mixture layer including an electrode active material, wherein the first layer includes a ceramic-carbon composite including a ceramic shell surrounding a hollow portion and a carbon coating layer surrounding the ceramic shell, wherein the hollow portion is in a vacuum state. The first layer may further include a binder. The first layer may include 90 to 99 wt % of the ceramic-carbon composite and 1 to 10 wt % of the binder. The first layer may have a thickness of 1 to 10 μm. The electrode may be a positive electrode or a negative electrode. According to an aspect of the present disclosure, provided is a secondary battery including an electrode. According to an aspect of the present disclosure, a method for fabricating a ceramic-carbon composite includes heating a first ceramic powder at a temperature of 1800 to 2200° C.; preparing a first mixture by mixing the first ceramic powder with a porous second ceramic powder or water; preparing a second mixture by mixing the first mixture with a curable resin and a carbon material; and evacuating the second mixture in a vacuum. The first ceramic powder and the second ceramic powder may independently include at least one selected from the group consisting of Al2O3, SiO2, ZrO2, and SiC. The method may further include pulverizing the first mixture. The method may further include removing metal impurities using magnetic force, after the pulverizing the