Non-aqueous electrolyte lithium secondary cell

• US 5,494,762 A
• Filed: 02/09/1995
• Issued: 02/27/1996
• Est. Priority Date: 09/01/1992
• Status: Expired due to Term

• Current Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Original Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Inventors: Kojima, Hisano, Hasegawa, Jun, Suzuki, Satoru, Saito, Hirohiko, Isoyama, Hirofumi
• Primary Examiner(s): Skapars, Anthony
• Application Number:
  US08/386,363
• Time in Patent Office: 383 Days
• Field of Search: 429/194, 429/218, 429/224, 429/221, 429/223, 252/182.1
• US Class Current: 429/221
• CPC Class Codes: C01G 45/02 Oxides; Hydroxides
• CPC Class Codes: C01G 45/1242 of the type [Mn2O4]-, e.g. LiMn2O4, Li[MxMn2-x]O4
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2002/77 by unit-cell parameters, atom positions or structure diagrams
• CPC Class Codes: C01P 2004/80 Particles consisting of a mixture of two or more inorganic phases
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/42 Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells H01M10/60 takes precedence
• CPC Class Codes: H01M 10/4235 Safety or regulating additives or arrangements in electrodes, separators or electrolyte H01M10/4242 takes precedence
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 2200/00 Safety devices for primary or secondary batteries
• CPC Class Codes: H01M 2200/10 Temperature sensitive devices
• CPC Class Codes: H01M 2200/20 Pressure-sensitive devices
• CPC Class Codes: H01M 2300/0025 Organic electrolyte
• CPC Class Codes: H01M 2300/0068 inorganic
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/38 of elements or alloys
• CPC Class Codes: H01M 4/40 Alloys based on alkali metals
• 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: H01M 4/587 : for inserting or intercalating light metals
• CPC Class Codes: H01M 4/62 : Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
• CPC Class Codes: H01M 4/661 : Metal or alloys, e.g. alloy coatings H01M4/669 take precedence
• CPC Class Codes: H01M 4/663 : containing carbon or carbonaceous materials as conductive part, e.g. graphite, carbon fibres
• CPC Class Codes: H01M 50/24 : adapted for protecting batteries from their environment, e.g. from corrosion thermal insulation H01M10/658
• CPC Class Codes: H01M 50/497 : Ionic conductivity
• CPC Class Codes: H01M 50/581 : in response to temperature
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries

Abstract

In order to improve the charge-discharge energy density of a lithium secondary cell with a nonaqueous electrolyte having such a construction that a metallic compound capable of occluding or releasing lithium is used as an electrode active material, lithium or a lithium alloy is used as a negative electrode material and a solution of a lithium salt is used as an electrolyte, the microstructure of the metallic compound is rendered acicular. Further, a lithium-containing metallic compound grown into such a columnar form that has the angle Θ to the normal of the surface of the substrate of 0°≦Θ<90° is used as the electrode active material.

Claims

1. A lithium secondary cell comprising a positive electrode, a negative electrode facing said positive electrode and a nonaqueous electrolyte interposed between said positive electrode and said negative electrode, wherein a metallic compound capable of occluding or releasing lithium is used as an electrode active material, said metallic compound having an acicular microstructure.

2. The lithium secondary cell according to claim 1, wherein said metallic compound capable of occluding or releasing lithium is a lithium-containing metallic compound.

3. The lithium secondary cell according to claim 1, wherein said metallic compound capable of occluding or releasing lithium is at least one member selected from the group consisting of LiMn₂ O₄, Li_x MnO₂, LiCoO₂, LiNiO₂, LiFeO₂ and LiV₃ O₈.

4. A lithium secondary cell comprising a positive electrode, a negative electrode facing said positive electrode and a nonaqueous electrolyte interposed between said positive electrode and said negative electrode, wherein a metallic compound capable of occluding or releasing lithium is used as an electrode active material, said electrode active material comprising a lithium-containing metal oxide grown into such a columnar form that the angle Θ

of a conductive substrate to the normal of the surface of said substrate is 0°

≦

Θ

<

90°

.

5. The lithium secondary cell according to claim 4 wherein said lithium-containing metal oxide is at least one member selected from the group consisting of LiMn₂ O₄, Li_x WO₃, LiCoO₂, LiNi₀.4 Co₀.6 O₂, Li_x MnO₂ and LiV₃ O₈.