EP0541889A1
Expired / Lapsed
EP
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Lithium secondary battery
Assignee: Sanyo Electric Co Ltd
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Filing: 1992-03-09
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Granted: —
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Expires: 2012-03-09
Abstract
Abstract Provided is a novel lithium secondary battery comprising a positive electrode (1) comprising a compound capable of occluding and discharging lithium, a negative electrode (2) principally comprising a carbon material which comprises a graphite as an only or principal component, a separator (3) placed between said positive electrode (1) and said negative electrode (2); and an electrolyte solution of an electrolyte solute dissolved in a solvent comprising at least one specific cyclic compound. The lithium secondary battery has a large capacity, small self-discharge rate and excellent cycle characteristics and high charge-discharge efficiency.
Inventors
- 👤 Masahisa Fujimoto
- 👤 Noriyuki Yoshinaga
- 👤 Koji Ueno
- 👤 Nobuhiro Furukawa
- 👤 Toshiyuki Nohma
- 👤 Masatoshi Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 06:38
CPC Classifications
H; H01; H01M; H01M4/00; H01M4/02; H01M4/13; H01M4/131; H01M10/00; H01M10/05; H01M10/052; H01M10/0525; H01M10/056; H01M10/0564; H01M10/0566; H01M10/0569; H01M4/36; H01M4/48; H01M4/485; H01M4/50; H01M4/505; H01M4/52; H01M4/525; H01M4/60; H01M4/58; H01M4/583; H01M4/587; H01M6/00; H01M6/14; H01M6/16; H01M6/162; H01M6/164; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
98 words
A lithium secondary battery comprising: a positive electrode principally comprising a compound capable of occluding and discharging lithium, a negative electrode principally comprising a carbon material which comprises a graphite as an only or principal component, a separator placed between said positive electrode and said negative electrode; and an electrolyte solution of an electrolyte solute dissolved in a solvent comprising at least one cyclic compound selected from the group consisting of ethylene carbonate, ethylene thiocarbonate, γ-thiobutyrolactone, α-pyrrolidone, γ-butyrolactone, propylene carbonate, 1,2-butylene carbonate, 2,3-butylene carbonate, γ-valerolactone, γ-ethyl-γ-butyrolactone, β-methyl-γ-butyrolactone, thiolane, pyrazolidine, pyrrolidine, tetrahydrofuran, 3-methyltetrahydrofuran, sulfolane, 3-methylsulfolane, 2-methylsulfolane, 3-ethylsulfolane and 2-ethylsulfolane.
Claim 2
Dependent Claim
14 words
A lithium secondary battery according to Claim 1, wherein said solvent is ethylene carbonate.
Claim 3
Dependent Claim
16 words
A lithium secondary battery according to Claim 1, wherein said solvent comprises ethylene carbonate and γ-butyrolactone.
Claim 4
Dependent Claim
17 words
A lithium secondary battery according to Claim 1, wherein said solvent comprises ethylene carbonate, γ-butyrolactone and sulfolane.
Claim 5
Dependent Claim
23 words
A lithium secondary battery according to Claim 3 or Claim 4, wherein said solvent comprises at least 10% by volume of ethylene carbonate.
Claim 6
Dependent Claim
17 words
A lithium secondary battery according to Claim 1, wherein said solvent further comprises a low-boiling point solvent.
Claim 7
Dependent Claim
19 words
A lithium secondary battery according to Claim 6, wherein said solvent comprises ethylene carbonate and a low-boiling point solvent.
Claim 8
Dependent Claim
20 words
A lithium secondary battery according to Claim 6, wherein said solvent comprises ethylene carbonate, γ-butyrolactone and a low-boiling point solvent.
Claim 9
Dependent Claim
21 words
A lithium secondary battery according to Claim 6, wherein said solvent comprises ethylene carbonate, γ-butyrolactone, sulfolane and a low-boiling point solvent.
Claim 10
Dependent Claim
37 words
A lithium secondary battery according to any one of Claims 6 through 9, wherein said low-boiling point solvent is at least one member selected from the group consisting of dimethyl carbonate, diethyl carbonate, 1,2-dimethoxyethane, 1,2-diethoxyethane and ethoxymethoxyethane.
Claim 11
Dependent Claim
17 words
A lithium secondary battery according to Claim 6, wherein said solvent comprises ethylene carbonate and dimethyl carbonate.
Claim 12
Dependent Claim
17 words
A lithium secondary battery according to Claim 6, wherein said solvent comprises ethylene carbonate and diethyl carbonate.
Claim 13
Dependent Claim
19 words
A lithium secondary battery according to Claim 6, wherein said solvent comprises ethylene carbonate, dimethyl carbonate and diethyl carbonate.
Claim 14
Dependent Claim
28 words
A lithium secondary battery according to any one of Claims 11 through 13, wherein said solvent comprises ethylene carbonate in an amount of 20 to 80% by volume.
Claim 15
Dependent Claim
25 words
A lithium secondary battery according to any of Claims 1 to 14, wherein said graphite has an average particle diameter of 1 to 30 µm.
Claim 16
Dependent Claim
32 words
A lithium secondary battery according to any of Claims 1 to 15, wherein said graphite has a d-value of the lattice plane (002) in X-ray diffraction pattern of 3.35 to 3.40 Å.
Claim 17
Dependent Claim
32 words
A lithium secondary battery according to any of Claims 1 to 16, wherein said graphite has a crystallite size in the c-axis direction in X-ray diffraction pattern of at least 150 Å.
Claim 18
Dependent Claim
25 words
A lithium secondary battery according to any of Claims 1 to 17, wherein said graphite has a specific surface area of 0.5 to 50 m²/g.
Claim 19
Dependent Claim
24 words
A lithium secondary battery according to any of Claims 1 to 18, wherein said graphite has a true density of 1.9 to 2.3 g/cm³.
Claim 20
Dependent Claim
47 words
A lithium secondary battery according to any of Claims 1 to 19, wherein said carbon material principally comprising a graphite is a mixture of the graphite and a carbon material having a crystallite size in the c-axis in X-ray diffraction pattern of not more than 8 Å.
Claim 21
Dependent Claim
48 words
A lithium secondary battery according to any of Claims 1 to 19, wherein said carbon material principally comprising a graphite is obtained by calcining a mixture of the graphite and pitch and has a crystallite size in the c-axis in X-ray diffraction pattern of at least 150 Å.
Claim 22
Dependent Claim
51 words
A lithium secondary battery according to any of Claims 1 to 21 wherein said compound capable of occluding and discharging lithium is represented by the formula Li x MO₂ or Li y M₂O₄, wherein M is a transition element, and 0 ≦ x ≦ 1 and 0 ≦ y ≦ 2.
Claim 23
Dependent Claim
36 words
A lithium secondary battery according to any of Claims 1 to 21, wherein said compound capable of occluding and discharging lithium is a metal oxide intercalated graphite, anion intercalated graphite or halogen or halide intercalated graphite.
Claim 24
Dependent Claim
32 words
A lithium secondary battery according to any of Claims 1 to 21, wherein said compound capable of occluding and discharging lithium is a conductive polymer or a conductive polymer containing a dopant.
Claim 25
Dependent Claim
31 words
A lithium secondary battery according to any of Claims 1 to 24, wherein said electrolyte solute is selected from the group consisting of LiPF6, LiBF₄, LiClO₄, LiCF₃SO₃, LiC₄F₉SO₃, LiN(CF₃SO₂)₂ and LiAsF₆.
References Cited (Backward Citations)
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