Pre-lithiation using lithium metal and inorganic composite layer

Patent metadata

Field	Value
Publication number	US-2019372118-A1
Application number	US-201916541737-A
Country	US
Kind code	A1
Filing date	Aug 15, 2019
Priority date	Aug 11, 2017
Publication date	Dec 5, 2019
Grant date	—

Abstract

A method of pre-lithiating a negative electrode for a secondary battery, including: dispersing a lithium metal powder, an inorganic material powder and a binder in a solvent to prepare a mixed solution; and applying the mixed solution to the negative electrode to form a lithium metal-inorganic composite layer on the negative electrode, thereby forming the pre-lithiated negative electrode. Also, a method for pre-lithiating a negative electrode having a high capacity by a simple process. Further, a negative electrode for a secondary battery manufactured through the pre-lithiation method provided in the present invention has an improved initial irreversibility, and secondary batteries manufactured using such a negative electrode for a secondary battery have excellent charge/discharge efficiency.

First claim

1 . A method of pre-lithiating a negative electrode for a secondary battery, the method comprising:
dispersing a lithium metal powder, an inorganic material powder and a binder in a solvent to prepare a mixed solution; and applying the mixed solution to the negative electrode to form a lithium metal-inorganic composite layer on the negative electrode, thereby forming the pre-lithiated negative electrode.

2 . The method of claim 1 , wherein a thickness of the lithium metal-inorganic composite layer is 0.5 to 20 μm.

3 . The method of claim 1 , wherein the inorganic material powder comprises at least one selected from the group consisting of alumina (Al 2 O 3 ), titanium dioxide (TiO 2 ), zirconium dioxide (ZrO 2 ), silicon dioxide (SiO 2 ), tin oxide (SnO 2 ), cerium oxide (CeO 2 ), magnesium oxide (MgO), calcium oxide (CaO), and yttria (Y 2 O 3 ).

4 . The method of claim 1 , further comprising:
prior to dispersing, adding the lithium metal powder, the inorganic material powder and the binder to the solvent, wherein the lithium metal powder in an amount of 20 to 40 parts by weight, the inorganic material powder in an amount of 50 to 80 parts by weight, and the binder in an amount of 1 to 10 parts by weight are added to the solvent.

5 . The method of claim 1 , wherein the mixed solution is applied to form the lithium metal-inorganic composite layer by coating, spraying, or lamination.

6 . The method of claim 1 , wherein particles of the lithium metal powder have an average particle diameter of 5 to 50 μm.

7 . The method of claim 1 , wherein particles of the inorganic particle powder have an average particle diameter of 0.1 to 10 μm.

8 . The method of claim 1 , wherein after an initial activation charge, the lithium metal-inorganic composite layer is converted to an inorganic material layer due to the fact that lithium metal in the lithium metal-inorganic composite layer does not remain in metallic form.

9 . The method of claim 1 , wherein the negative electrode comprises silicon oxide.

10 . A negative electrode for a secondary cell produced by the method of pre-lithiating a negative electrode according to claim 1 .

11 . A secondary battery comprising the negative electrode according to claim 10 .

Assignees

• Lg Chemical Ltd

Inventors

• Woo Sang Wook
• Kim Eun Kyung
• Kang Yoon Ah
• Song Jun Hyuk
• Chae Oh Byong

Classifications

• H01M4/0459

  Electrochemical doping, intercalation, occlusion or alloying · CPC title

• H01M10/4235

  Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence) · CPC title

• H01M4/0461

  Electrochemical alloying · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/0495

  Chemical alloying · CPC title