Solid electrolyte, method for preparing the same, and battery using the same

• US 20040151986A1
• Filed: 01/15/2004
• Published: 08/05/2004
• Est. Priority Date: 01/30/2003
• Status: Active Grant

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Jin, Young-Gu, Park, Young-Sin, Lee, Seok-Soo, Lee, Jong-Heun
• Granted Patent: US 7,273,682 B2
• Time in Patent Office: Days
• US Class Current: 429/322
• CPC Class Codes: C03C 3/14 containing boron
• CPC Class Codes: H01M 10/0436 Small-sized flat cells or batteries for portable equipment
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0562 Solid materials
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A solid electrolyte including a composition represented by Formula 1 below is provided: aLi₂O-bB₂O₃-cM-dX (1) wherein M is at least one selected from the group consisting of TiO₂, V₂O₅, WO₃, and Ta₂O₅; X is at least one selected from LiCl and Li₂SO₄; 0.4<a<0.55; 0.4<b<0.55; 0.02<c<0.05; a+b+c=1, and 0≦d<0.2. A method for preparing the solid electrolyte and a battery using the solid electrolyte are also provided. The solid electrolyte exhibits high ionic conductivity. Lithium and thin film batteries using the solid electrolyte are improved in charge/discharge rate, power output, and cycle life.

Claims

1. A solid electrolyte comprising a composition represented by Formula 1 below:

aLi₂O-bB₂O₃-cM-dX 

 

(1)

wherein M is at least one selected from the group consisting of TiO₂, V₂O₅, WO₃, and Ta₂O₅;

X is at least one selected from LiCl and Li₂SO₄;

0.4<

a<

0.55;

0.4<

b<

0.55;

0.02<

c<

0.05;

a+b+c=1, and 0≦

d<

0.2.

2. The solid electrolyte according to claim 1, wherein a is in the range of 0.45 to 0.52, b is in the range of 0.45 to 0.52, c is in the range of 0.03 to 0.04, and d is in the range of 0.001 to 0.15.

3. A method for preparing a solid electrolyte comprising a composition represented by Formula 1 below:

aLi₂O-bB₂O₃-cM-dX 

 

(1)

wherein M is at least one selected from the group consisting of TiO₂, V₂O₅, WO₃, and Ta₂O₅;

X is at least one selected from LiCl and Li₂SO₄;

0.4<

a<

0.55;

0.4<

b<

0.55;

0.02<

c<

0.05;

a+b+c=1, and 0≦

d<

0.2,

the method comprising;

(a) mixing a Li₂O precursor compound;

B₂O₃; and

at least one compound selected from the group consisting of TiO₂, V₂O₅, WO₃, and Ta₂O₅, followed by milling;

(b) heating the resultant powder mixture so that the Li₂O precursor compound is thermally decomposed into Li₂O;

(c) heating the resultant mixture to obtain a uniformly molten glass; and

(d) quenching the molten glass to obtain a glassy solid electrolyte.

4. The method according to claim 3, further comprising adding at least one selected from LiCl and Li₂SO₄ to the mixture of step (a).

5. The method according to claim 3, wherein in step (b), Li₂O is decomposed from the Li₂O precursor compound at a temperature of 600 to 800°

C.

6. The method according to claim 3, wherein in step (c), the molten glass is obtained at a temperature of 900 to 1,500°

C.

7. The method according to claim 3, wherein in step (d), the molten glass is quenched at a temperature of 0 to 25°

C.

8. A lithium battery using a solid electrolyte comprising a composition represented by Formula 1 below:

aLi₂O-bB₂O₃-cM-dX 

 

(1)

wherein M is at least one selected from the group consisting of TiO₂, V₂O₅, WO₃, and Ta₂O₅;

X is at least one selected from LiCl and Li₂SO₄;

0.4<

a<

0.55;

0.4<

b<

0.55;

0.02<

c<

0.05;

a+b+c=1, and 0≦

d<

0.2.

9. A thin film battery using a solid electrolyte comprising a composition represented by Formula 1 below:

aLi₂O-bB₂O₃-cM-dX 

 

(1)

wherein M is at least one selected from the group consisting of TiO₂, V₂O₅, WO₃, and Ta₂O₅;

X is at least one selected from LiCl and Li₂SO₄;

0.4<

a<

0.55;

0.4<

b<

0.55;

0.02<

c<

0.05;

a+b+c=1, and 0≦

d<

0.2.