Anode active material comprising metal phosphide coating on surface of carbon material, preparation method therefor, nonaqueous lithium secondary battery comprising anode active material, and manufacturing method therefor

Patent metadata

Field	Value
Publication number	US-2022216462-A1
Application number	US-202017595157-A
Country	US
Kind code	A1
Filing date	May 13, 2020
Priority date	May 13, 2019
Publication date	Jul 7, 2022
Grant date	—

Abstract

The present invention provides a method for preparing an anode active material for a nonaqueous lithium secondary battery, comprising the steps of: preparing a carbon-based material; forming a precursor coating layer comprising Me and A (wherein A is O or S) on the surface of the carbon-based material; supplying a P precursor to the precursor coating layer of the carbon-based material; and converting at least a part of the precursor coating layer into a compound represented by Mex1Py1 (wherein x1>0 and y1>0) by the reaction of the precursor coating layer and the P precursor, thereby forming a phosphide coating layer, wherein Me is at least one type of the same metal element selected from among Mo, Ni, Fe, Co, Ti, V, Cr, Nb and Mn.

First claim

1 . A method for preparing an anode active material for a nonaqueous lithium secondary battery, the method comprising:
preparing a carbon-based material; forming a precursor coating layer containing Me and A (A is O or S) on the surface of the carbon-based material; supplying a P precursor to the precursor coating layer on the carbon-based material; and reacting the precursor coating layer and the P precursor to convert at least a portion of the precursor coating layer into a compound represented by chemical formula Me x1 P y1 (x1>0 and y1>0), thereby forming a phosphide coating layer, wherein Me is at least one same metal element selected from Mo, Ni, Fe, Co, Ti, V, Cr, Nb, and Mn.

2 . The method of claim 1 , wherein the phosphide coating layer contains a composite of a compound represented by chemical formula Me x1 P y1 (x1>0 and y1>0) and a compound represented by chemical formula Me x2 A y2 (A is O or S; and x2>0 and y2>0).

3 . The method of claim 1 , wherein in the supplying of the P precursor, the P precursor is supplied as a gas source.

4 . The method of claim 1 , wherein in the supplying of the P precursor, the P precursor is mixed, as a solid or liquid source, with the carbon-based material.

5 . The method of claim 1 , wherein the P precursor is at least one type selected from the group consisting of sodium hypophosphite (NaH 2 PO 2 ), phosphoric acid (H 3 PO 4 ), phosphorous trichloride (PCl 3 ), phosphorous, red (P), Phosphorous, black (P), and triphenyl phosphine (C 18 H 15 P).

6 . The method of claim 1 , wherein in the forming of the coating layer, heat treatment is conducted for reaction of the precursor coating layer and the P precursor.

7 . The method of claim 1 , wherein in the converting, P of the P precursor is substituted for A in the precursor coating layer.

8 . The method of claim 1 , wherein the P precursor contains no metal element Me.

9 . The method of claim 1 , wherein the forming of the phosphide coating layer is performed in an inert gas atmosphere at 500-1000° C. for 1-10 hours.

10 . An anode active material for a nonaqueous lithium secondary battery, the anode active material comprising:
a carbon-based material; and a coating layer formed on the surface of the carbon-based material and containing a compound represented by chemical formula Me x1 P y1 (x1>0 and y1>0), wherein Me is at least one same metal element selected from the group consisting of Mo, Ni, Fe, Co, Ti, V, Cr, Nb, and Mn.

11 . The anode active material of claim 10 , wherein:
Me includes Mo; Me x1 P y1 includes at least one type from the group consisting of MoP, MoP 2 , Mo 3 P, MoP 4 , Mo 4 P 3 , and Mo 8 P 5 ; and Me x2 A y2 includes at least one type selected from the group consisting of MoO, MoO 2 , and MoO 3 .

12 . The anode active material of claim 11 , wherein the anode active material has distinctive peaks in the vicinity of 2θ=32.0° and 43.0° in an X-ray diffraction pattern.

13 . The anode active material of claim 11 , wherein the anode active material has distinctive peaks in the vicinity of 2θ=23.9°, 29.5°, and 41.7° in an X-ray diffraction pattern.

14 . The anode active material of claim 10 , wherein the coating layer further contains a compound represented by chemical formula Me x2 A y2 (A is O or S; and x2>0 and y2>0).

15 . The anode active material of claim 10 , wherein Me includes Ni, and Me x1 P y1 includes at least one type selected from the group consisting of Ni 5 P 2 , Ni 4 P 2 , Ni 3 P, Ni 12 P 5 , Ni 2 P, Ni 5 P 4 , NiP, NiP 2 , and NiP 3 .

16 . The anode active material of claim 10 , wherein Me includes Fe, and Me x1 P y1 includes at least one type from the group consisting of FeP, Fe 2 P, Fe 3 P, and Mo 8 P 5 .

17 . The anode active material of claim 10 , wherein Me includes Co, and Me x1 P y1 includes at least one type from the group consisting of CoP and Co 2 P.

18 . The anode active material of claim 10 , wherein the coating layer is uniformly or partially formed on the surface of the carbon-based material.

19 . The anode active material of claim 10 , wherein the carbon-based material includes at least one type selected from the group consisting of artificial graphite, natural graphite, graphitized carbon fibers, graphitized mesocarbon microbeads, petroleum coke, resin burned bodies, carbon fibers, and pyrolytic carbon.

20 . The anode active material of claim 19 , wherein the carbon-based material has a particle diameter of 20 μm or less.

Assignees

• Keri Korea Electrotechnology Res Inst
• Univ Industry Cooperation Group Kyung Hee Univ

Inventors

• Lee Sang Min
• Park Min-Sik
• Lee Chul Ho
• Choi Jeong Hee

Classifications

• C01B25/08 Primary

  Other phosphides · CPC title

• C01B32/21 Primary

  After-treatment · CPC title

• C01P2002/85

  by XPS, EDX or EDAX data · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title