Negative active material and lithium battery including negative active material

Patent metadata

Field	Value
Publication number	US-10164251-B2
Application number	US-201514956293-A
Country	US
Kind code	B2
Filing date	Dec 1, 2015
Priority date	Dec 23, 2014
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

A negative active material includes a silicon-based alloy, wherein the silicon-based alloy includes silicon (Si); a first metal (M 1 ) selected from titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), gallium (Ga), and germanium (Ge), and at least one additional element (A), which is included in the silicon-based alloy and on a surface of silicon-based alloy, selected from carbon (C), boron (B), sodium (Na), nitrogen (N), phosphorous (P), sulfur (S), and chlorine (Cl), and the silicon-based alloy has an internal porosity of about 35% or less. A lithium battery including the negative active material may have improved lifespan characteristics.

First claim

What is claimed is:

1. A negative active material comprising a porous silicon-based alloy,
wherein the porous silicon-based alloy comprises silicon (Si); a first metal (M 1 ); and an additional element (A);
the first metal (M 1 ) is selected from titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), gallium (Ga), and germanium (Ge);
the additional element (A) is at least one selected from carbon (C), boron (B), sodium (Na), nitrogen (N), phosphorous (P), sulfur (S), and chlorine (Cl);
the additional element (A) is inside the porous silicon-based alloy and on surfaces of the porous silicon-based alloy; and
an internal porosity of the silicon-based alloy is in the range of 24% to 35%, wherein the porosity is determined by Mathematical Equation 1:

⁢

Mathematical
⁢

⁢
Equation
⁢

⁢
1

Internal
⁢

⁢
porosity
⁢

⁢
of
⁢

⁢
the
⁢

⁢
silicon
⁢

-

⁢
based
⁢

⁢
alloy
⁢

⁢

(
%
)

=

[

1
-

density
⁢

⁢
of
⁢

⁢
the
⁢

⁢
alloy
⁢

⁢
measured

under
⁢

⁢
a
⁢

⁢
pressure
⁢

⁢
of
⁢

⁢
20
⁢

⁢
kN

true
⁢

⁢
density
⁢

⁢
of
⁢

⁢
the
⁢

⁢
alloy

]

×
100.

2. The negative active material of claim 1 , wherein the silicon-based alloy comprises:
a matrix comprising the Si and the first metal (M 1 );
silicon nanoparticles; and
the additional element (A),
wherein the silicon nanoparticles are dispersed in the matrix, and the additional element (A) is comprised in the matrix and disposed on a surface of the silicon-based alloy.

3. The negative active material of claim 2 , wherein the matrix comprises a compound phase comprising Si and the first metal (M 1 ) and the silicon nanoparticles comprise a single phase of Si.

4. The negative active material of claim 2 , wherein at least a portion of the additional element (A) of the matrix is in the form of a silicide.

5. The negative active material of claim 1 , wherein the first metal (M 1 ) is Fe.

6. The negative active material of claim 1 , wherein the silicon-based alloy further comprises an oxygen (O) atom.

7. The negative active material of claim 6 , wherein the silicon-based alloy comprises:
a matrix comprising Si, the first metal (M 1 ), and the O atom;
silicon nanoparticles; and
the additional element (A),
wherein the silicon nanoparticles are dispersed in the matrix, and the additional element (A) is in the matrix and on a surface of the silicon-based alloy.

8. The negative active material of claim 7 , wherein the matrix comprises a compound phase comprising Si and the first metal (M 1 ) and a compound phase comprising Si and the O atom, and
wherein the silicon nanoparticles comprise a single phase of Si.

9. The negative active material of claim 8 , wherein the matrix further comprises a compound phase comprising the first metal (M 1 ) and the O atom.

10. The negative active material of claim 1 , wherein the silicon-based powder alloy further comprises a second metal (M 2 ) selected from manganese (Mn), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), silver (Ag), tin (Sn), tantalum (Ta), and tungsten (W).

11. The negative active material of claim 1 ,
wherein the silicon-based alloy is represented by Si-M

Assignees

• Samsung Sdi Co Ltd

Inventors

• Suh Soonsung
• Kim Jaehyuk
• Chu Heeyoung
• Yoo Hana
• Kwon Seunguk
• Yoon Dukhyoung

Classifications

• H01M4/386 Primary

  Silicon or alloys based on silicon · CPC title

• C22C24/00

  Alloys based on an alkali or an alkaline earth metal · CPC title

• C22C21/00

  Alloys based on aluminium · CPC title

• B22F2999/00

  Aspects linked to processes or compositions used in powder metallurgy · CPC title

• H01M10/0525

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