Title of Invention

METHOD FOR REGULATING TERMINAL VOLTAGE OF CATHODE DURING OVERDISCHARGE AND CATHODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY

Abstract Disclosed is a method for regulating terminal voltage of a cathode during overdischarge. Also disclosed is a lithium secondary battery, which is low in capacity loss after overdischarge, having excellent capacity restorability after overdischarge and shows an effect of preventing a battery from swelling at a high temperature.
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We Claim:
1. A method for regulating terminal voltage of a cathode for a lithium secondary battery when electric potential difference (voltage) between a cathode and an anode is OV during over discharge, which comprises forming a cathode by adding to a cathode active material containing a first lithium transition metal oxide as herein before described capable of lithium ion intercalation/deintercalation, a second lithium transition metal oxide as herein before described of which an irreversible capacity in the first charge/discharge cycle is greater than that of the first lithium transition metal oxide, as an additive.
2. The method as claimed in claim 1, wherein the additive is added to the extent of providing irreversibly lithium ions at least in such an amount as to compensate for an irreversible lithium-consuming reaction in an anode caused by the SEI film formation on the surface of an anode during the first charge.
3. The method as claimed in claim 1, wherein the additive is a lithium nickel oxide represented by the following formula 1, or a lithium nickel oxide represented by the following formula 1 that is surface-coated with an oxide other than lithium nickel oxides:
[Formula 1]
(Formula Removed)
wherein, x is a number satisfying -0.5 4. The method as claimed in claim 3, wherein the oxide
other than lithium nickel oxides is an oxide or composite oxide
of at least one element selected from the group consisting of Al,
Mg, Si, P, C, Sc, Ti, V, Cr, Mn, Fe, Co, Cu, Zn, Mo, Zr and Nb.
5. A lithium secondary battery comprising a cathode (3) containing cathode active material containing a lithium transition metal oxide capable of lithium ion intercalation/ deintercalation, an anode (4), a separator (7) and a non-aqueous electrolyte (9) containing a lithium salt such as herein described and an electrolyte compound, such as herein described wherein the cathode comprises a cathode active material such as herein described.
6. The lithium secondary battery as claimed in claim 5, wherein the lithium salt is at least one selected from the group consisting of LiC1O4, LiCFsSO3, LiPF6, LiBF4, LiAsFe and LiN (CF3SO2) 2, and the electrolyte compound is at least one carbonate selected from the group consisting of ethylene carbonate (EC), propylene carbonate (PC), gamma-butyrolactone (GBL), diethyl carbonate (DEC), dimethyl carbonate (DMC), ethylmethyl carbonate (EMC) and methylpropyl carbonate (MFC).
7. The lithium secondary battery as claimed in claim 5-6,
wherein the cathode active material contains a lithium transition
metal oxide capable of lithium ion intercalation /
deintercalation and a lithium nickel oxide represented by the
following formula 1 in which nickel is partially substituted with
other elements (with the proviso that y is not 0) , or a lithium
nickel oxide represented by the following formula 1 that is
surface-coated with an oxide other than lithium nickel oxides, as
an additive:
[Formula 1]
(Formula Removed)
wherein, x is a number satisfying -0.5 8. The lithium secondary battery as claimed in claim 5,
wherein the oxide other than lithium nickel oxides is an oxide or
composite oxide of at least one element selected from the group consisting of Al, Mg, Si, P, C, So, Ti, V, Cr, Mn, Fe, Co, Cu, Zn, Mo, Zr and Nb.
9. The lithium secondary battery as claimed in claim 5-7,
wherein the compound represented by formula 1 forms a tetra-
coordinated planar structure, (Ni,M)04 and two tetra-coordinated
planar structures facing to each other share one side formed by
0-0 so as to form a primary chain.
10. The lithium secondary battery as claimed in claim 5-7, wherein the compound represented by formula 1 has the following lattice constants: a=3.7±0.5 3, b=2.8+0.5 D, c=9.2±0.5 D, α= 90°, ß= 90°and Y= 90.
11. The lithium secondary battery as claimed in claim 5-7, wherein the lithium transition metal oxide is at least one selected from the group consisting of LiCoOa, LiNiOa, LiMnOa, LiMnaO4, Li (NiaCobMnc) O2, LiNi1-d COdO2, LiCO1-dMndO2, LiNi1-d MndO2, Li
(NixCOyMnz) O4, LiMn2-nNinO4, LiMn2-nCOnO4, LiCoPO4 and LiFePO4, wherein 0 12. The lithium secondary battery as claimed in claim 5-7,
which comprises the additive for a cathode active material in an
amount of 0.1 to 10 parts by weight based on 100 parts by weight
of the cathode active material.

Documents:

3223-delnp-2005-abstract.pdf

3223-delnp-2005-claims.pdf

3223-delnp-2005-complete specification (as files).pdf

3223-delnp-2005-complete specification (granted).pdf

3223-delnp-2005-correspondence-others.pdf

3223-delnp-2005-correspondence-po.pdf

3223-delnp-2005-description (complete).pdf

3223-delnp-2005-drawings.pdf

3223-delnp-2005-form-1.pdf

3223-delnp-2005-form-18.pdf

3223-delnp-2005-form-2.pdf

3223-delnp-2005-form-3.pdf

3223-delnp-2005-form-5.pdf

3223-delnp-2005-pct-101.pdf

3223-delnp-2005-pct-210.pdf

3223-delnp-2005-pct-237.pdf

3223-delnp-2005-pct-304.pdf

3223-delnp-2005-pct-306.pdf

3223-delnp-2005-pct-308.pdf

3223-delnp-2005-petition-137.pdf


Patent Number 249902
Indian Patent Application Number 3223/DELNP/2005
PG Journal Number 47/2011
Publication Date 25-Nov-2011
Grant Date 22-Nov-2011
Date of Filing 20-Jul-2005
Name of Patentee LG CHEM, LTD
Applicant Address LG TWIN TOWER, 20, YOIDO-DONG, YOUNGDUNGPO-GU, SEOUL 150-721, KOREA.
Inventors:
# Inventor's Name Inventor's Address
1 SEUNG TAE HONG 8-408, LG CHEMICAL APARTMENT, 381-42, DORYONG-DONG, YUSEONG-GU, DAEJEONG 305-340, KOREA.
2 JIN HEE YEON 7-107, LG CHEMICAL APARTMENT, DORYONG-DONG, YUSEONG-GU, DAEJEON 305-340, KOREA.
3 SUNG KYUNG CHANG 1-201, MIDEUM VILLA, 166-9, DOHWA-2DONG, NAM-GU, INCHEON 402-808, KOREA.
4 HYEONG JIN KIM SEONG-GU, DAEJEON 305-810, KOREA.
5 DUK HYUN RYU 108-25, DOMA2-DONG, SEO-GU, DAEJEON 302-162 KOREA.
6 EUN YOUNG GOH 696, JANGJHANG-DONG, ILSAN-GU, GOYANG-SI, GYEONGGI-DO 411-380, KOREA.
7 HO CHUN LEE 106-1407, HANMAUL APARTMENT, 200-4, SONGGANG-DONG, YUSEONG-GU, DAEJEON 305-503, KOREA.
8 JUN YONG JEONG 107-408, HANBAT GARDEN APARTMENT, SANSUNG-DONG, CHUNG-GU, DAEJEON 301-211, KOREA.
PCT International Classification Number H01M
PCT International Application Number PCT/KR2004/002461
PCT International Filing date 2004-09-24
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10-2003-0066865 2003-09-26 Republic of Korea
2 10-2003-0066866 2003-09-26 Republic of Korea