Negative active material for rechargeable lithium battery and rechargeable lithium battery comprising same

Patent metadata

Field	Value
Publication number	US-2016344024-A1
Application number	US-201615150259-A
Country	US
Kind code	A1
Filing date	May 9, 2016
Priority date	May 19, 2015
Publication date	Nov 24, 2016
Grant date	—

Abstract

A negative active material for a rechargeable lithium battery includes a lithium titanate compound represented by Chemical Formula 1, where R, a Raman spectrum intensity ratio (I(F2 u )/I(F2 g )) of an F2 u peak in a range of about 200 cm −1 to about 300 cm −1 relative to an F2 g peak in a range of about 400 cm −1 to about 550 cm −1 is greater than or equal to about 0.7.
Li 4+x Ti 5−y M z O 12−n   Chemical Formula 1

In Chemical Formula 1, −0.2≦x≦0.2, −0.3≦y≦0.3, 0≦z≦0.3, −0.3≦n≦0.3, and M is selected from Mg, Al, Ca, Sr, Cr, V, Fe, Co, Ni, Zr, Zn, Si, Y, Nb, Ga, Sn, Mo, W, Ba, La, Ce, Ag, Ta, Hf, Ru, Bi, Sb, As, and a combination thereof.

First claim

What is claimed is:

1 . A negative active material for a rechargeable lithium battery, the negative active material comprising:
a lithium titanate compound represented by Chemical Formula 1, wherein R, a Raman spectrum intensity ratio (I(F2u)/I(F2g)) of an F2u peak in a range of about 200 cm −1 to about 300 cm −1 relative to an F2g peak in a range of about 400 cm −1 to about 550 cm −1 , is greater than or equal to about 0.7:
Li 4+x Ti 5−y M z O 12−n   Chemical Formula 1

wherein, in Chemical Formula 1, −0.25≦x≦0.2, −0.3≦y≦0.3, 0≦z≦0.3, −0.3≦n≦0.3, and M is selected from Mg, Al, Ca, Sr, Cr, V, Fe, Co, Ni, Zr, Zn, Si, Y, Nb, Ga, Sn, Mo, W, Ba, La, Ce, Ag, Ta, Hf, Ru, Bi, Sb, As, and a combination thereof.

2 . The negative active material of claim 1 , wherein the R is about 0.7 to about 1.

3 . The negative active material of claim 1 , wherein the Raman spectrum is measured using a laser light source.

4 . A rechargeable lithium battery comprising:
a negative electrode comprising a lithium titanate compound represented by Chemical Formula 1, wherein R, a Raman spectrum intensity ratio (I(F2u)/I(F2g)) of an F2u peak in a range of about 200 cm −1 to about 300 cm −1 relative to an F2g peak in a range of about 400 cm −1 to about 550 cm −1 is greater than or equal to about 0.7; a positive electrode comprising a positive active material; and an electrolyte:
Li 4+x Ti 5−y M z O 12−n   Chemical Formula 1

wherein, in Chemical Formula 1, −0.2≦x≦0.2, −0.3≦y≦0.3, 0≦z≦0.3, −0.3≦n≦0.3, and M is selected from Mg, Al, Ca, Sr, Cr, V, Fe, Co, Ni, Zr, Zn, Si, Y, Nb, Ga, Sn, Mo, W, Ba, La, Ce, Ag, Ta, Hf, Ru, Bi, Sb, As, and a combination thereof.

5 . The rechargeable lithium battery of claim 4 , wherein the R is about 0.7 to about 1.

6 . The rechargeable lithium battery of claim 4 , wherein the positive active material comprises a compound represented by Chemical Formula 2, a compound represented by Chemical Formula 3, a compound represented by Chemical Formula 4, or a mixture thereof:
Li x TO 2−z L z   Chemical Formula 2
wherein, in Chemical Formula 2, T is M′ 1−k A k , is Ni 1−d−e Mn d Co e , 0.65≦d+e≦0.85, 0.1≦e≦0.4, A is a dopant, 0≦k<0.05, L is selected from F, S, P and a combination thereof, 0.95≦x≦1.05, and 0≦z≦2,
Li a2 Mn 1−b2 Q b2 O 4−α2   Chemical Formula 3

wherein, in Chemical Formula 3, 0.90≦a2≦1.8, 0≦b2≦0.5, 0≦α2<2, and Q is selected from Mg, La, Tb, Gd, Ce, Pr, Nd, Sm, Ba, Sr, Ca, and a combination thereof,
Li a3 Mn 1−b3 G b3 O 2−α3   Chemical Formula 4

wherein, in Chemical Formula 4, 0.90≦a3≦1.8, 0<b3≦0.5, 0≦α3≦2, and G is selected from Mg, La, Tb, Gd, Ce, Pr, Nd, Sm, Ba, Sr, Ca, and a combination thereof.

7 . The rechargeable lithium battery of claim 4 , wherein the positive electrode further comprises activated carbon.

8 . The rechargeable lithium battery of claim 7 , wherein the positive active material and the activated carbon are mixed to a ratio of 99:1 wt % to 89:11 wt %.

9 . The rechargeable lithium battery of claim 6 , wherein the dopant is selected from B, Ca, Zr, S, F, P, Bi, Al, Mg, Zn, Sr, Cu, Fe, Ga, In, Cr, Ge and Sn.

Assignees

• Samsung Sdi Co Ltd

Inventors

• Lee Soojeong
• Kim Young-Kee
• Shin Dong-Hyun
• Park Sun-Il
• Um Sujin

Classifications

• H01M4/625

  Carbon or graphite · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M4/502

  for non-aqueous cells (H01M4/505 takes precedence) · CPC title

• H01M4/483 Primary

  for non-aqueous cells (H01M4/485 takes precedence) · CPC title

• H01M10/0525

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