Positive electrode activator for lithium secondary battery and lithium secondary battery

• US 6,458,488 B1
• Filed: 10/13/2000
• Issued: 10/01/2002
• Est. Priority Date: 10/14/1999
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kasai, Masahiro, Honbo, Kyoko, Gotoh, Akihiro, Muranaka, Yasushi, Hotta, Yoshiji
• Primary Examiner(s): Chaney, Carol
• Assistant Examiner(s): YUAN, DAH WEI D
• Application Number:
  US09/689,797
• Time in Patent Office: 718 Days
• Field of Search: 429/209, 429/218.1, 429/224
• US Class Current: 429/224
• CPC Class Codes: H01M 4/131 Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/485 of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy H01M4/505, H01M4/525 take precedence
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A lithium secondary battery characterized by a high power capacity and a long service life has a negative electrode 3, a positive electrode 2 and a non-aqueous electrolyte containing lithium salt. The lithium secondary battery is characterized by further comprising multiple oxide represented by a general formula Li_x+aMn_2−a−bM_bQ_cO_4+d (where M denotes at least one element selected from among Ni, Fe, Co, Cu and Cr; Q denotes at least one element selected from among C, N, S, P, Si, F, Cl, I and Br; and x, a, b, c and d are within the range of 0≦x≦) 1.1, 0≦a≦0.5, 0.05≦b≦1.0, 0.000001≦c<0.05 and 0≦d≦0.1, respectively) as a positive electrode activator.

Claims

1. A positive electrode activator for a lithium secondary battery including non-aqueous electrolyte and including a negative electrode, a positive electrode and lithium salt;

said positive electrode activator for the lithium secondary battery characterized by inclusion of a multiple oxide represented by a general formula Li_x+aMn<sub>2−

a−

b</sub>M_bQ_cO_4+d (where M denotes at least one element selected from among Ni, Fe, Co, Cu and Cr;

Q denotes at least one element selected from among C, N, S, P, Si, F, Cl, I and Br; and

x, a, b, c and d are within the range of 0≦

x≦

1.1 0≦

a≦

0.5, 0.05≦

b≦

1.0, 0.000001≦

c<

0.05and 0≦

d≦

0.1, respectively).

5. The positive electrode activator according to claim 1, where c is in the range of 0.00001≦

c≦

0.01.

2. A positive electrode activator for a lithium secondary battery including non-aqueous electrolyte and including a negative electrode, a positive electrode and lithium salt, wherein said positive electrode activator comprises;

(1) a multiple oxide represented by a general formula Li_x+aMn<sub>2−

a−

b</sub>M_bQ_cO_4+d (where M denotes at least one element selected from among Ni, Fe, Co, Cu and Cr;

Q denotes at least one element selected from among C, N, S, P, Si, F, Cl, I and Br; and

x, a, b, c and d are within the range of 0≦

x≦

1.1, 0≦

a≦

0.5, 0.05≦

b≦

1.0, 0.000001≦

c≦

0.01 and 0≦

d≦

0.1, respectively), and

(2) is a material which is in the form of particles, and where Q has a higher density in a surface layer of the particles than inside the particles.

3. A positive electrode activator for a lithium secondary battery including non-aqueous electrolyte and including a negative electrode, a positive electrode and lithium salt;

said positive electrode activator characterized by inclusion of a multiple oxide represented by a general formula Li_x+aMn<sub>2−

a−

b</sub>M_bQ_cO_4+d (where M denotes at least one element selected from among Ni, Fe, Co, Cu and Cr;

Q denotes at least one element selected from among C, N, S, P, Si, F, Cl, I and Br; and

x, a,b, c and d are within the range of0≦

x≦

1.1, 0≦

a≦

0.5, 0.05≦

b≦

1.0, 0.000001≦

c<

0.05 and 0≦

d≦

0.1, respectively).

6. The positive electrode activator according to claim 3, where c is in the range of 0.00001≦

c≦

0.01.

4. A positive electrode activator for a lithium secondary battery including non-aqueous electrolyte and including a negative electrode, a positive electrode and lithium salt;

said positive electrode activator comprising a multiple oxide being represented by a general formula Li_x+aMn<sub>2−

a−

b</sub>M_bQ_cO_4+d (where M denotes at least one element selected from among Ni, Fe, Co, Cu and Cr;

Q denotes at least one element selected from among C, N, S, P, Si, F, Cl, I and Br; and

x, a,b,c and d are with in the range of0≦

x≦

1.1, 0≦

a≦

0.5, 0.05≦

b≦

1.0, 0.000001≦

c≦

0.01 and 0≦

d≦

0.1, respectively), and

wherein the positive electrode activator is in the form of particles, where Q of said multiple oxide has a higher density in a surface layer of the particles than inside the particles.