Ube Industries, Inc.

Other

Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Honda Giken Kogyo K.k.

Sanyo Electric Co., Ltd.

Toshikazu Hamamoto

Koji Abe

Akira Ueki

Yasuo Matsumori

Tsutomu Takai

Kazuhiro Miyoshi

Sumio Umemura

Shoichiro Watanabe

Nobuyuki Kuroda

Atsuo Hitaka

Nagaaki Takamitsu

Shusaku Goto

Masaru Takagi

Sumihito Ishida

Yoshihiro Ushigoe

Akikazu Ito

Yasuhiko Toda

Kozaburo Yoshida

Yukio Nakada

Motojirou Aoi

Masatoshi Takahashi

Hiroshi Inoue

Hideharu Takezawa

Katsumasa Harada

Takashi Takeuchi

Tetsuji Hirano

Ryoji Sugise

Shigeru Yao

Shyusei Ohya

Mitsuo Yamanaka

Yukihiko Asano

Hajime Konishi

Takato Nakamura

Shigeyuki Unoki

Masahiko Watanabe

Yohsuke Ueno

Katsuo Imatani

Yukio Ishiuchi

Kenji Matsubara

Tetsuro Shimano

Takashi Kohno

Yoshiyuki Miwa

Noriyuki Ohira

Motoki Yuguchi

Katsumi Yamashita

Zensaku Yasutake

Michishige Sakai

Hiroshi Waragaya

Makoto Nagata

Iwao Ishii

Eiji Kaneko

Hiroyoshi Ootsuki

Makoto Sanada

Hiroshi Yamashita

Shinichiro Izawa

The sudden generation of heat being frequently caused in the case of the overcharge of a lithium secondary cell which have a positive electrode comprising a composite metal oxide of lithium and cobalt or a composite metal oxide of lithium and nickel, a negative electrode comprising metallic lithium, a lithium alloy or a material capable of occluding and releasing lithium, and a nonaqueous electrolyte solution comprising a nonaqueous solvent and an electrolyte dissolved therein can be efficiently prevented by the addition, to the nonaqueous electrolyte solution, of an organic compound which, when the lithium secondary cell is overcharged, decomposes into a decomposition product capable of dissolving out the cobalt or nickel contained in the positive electrode and depositing it ion the negative electrode (for example, a tert-alkylbenzene derivative).

Lithium secondary battery and non-aqueous electrolytic solution

A non-aqueous electrolyte comprising (i) a non-aqueous solvent, especially mainly composed of a cyclic carbonate and a cyclic ester and optionally a linear carbonate, and (ii) an electrolyte salt, especially LiBF, dissolved therein and (iii) a vinyl sulfone derivative having the formula (I): wherein R indicates a Cto Calkyl group, Cto Calkenyl group, or Cto Ccycloalkyl, and also a lithium secondary battery using the same are disclosed.

Non-aqueous electrolyte and lithium secondary battery using the same

A non-aqueous electrolytic solution favorably employable for a lithium secondary battery employs a non-aqueous electrolytic solution which comprises a non-aqueous solvent and an electrolyte which further contains 0.001 to 0.8 weight % of a biphenyl derivative having the formula: in which each of Yand Yrepresents hydroxyl, alkoxy, hydrocarbyl, hydrogen, acyloxy, alkoxycarbonyloxy, alkylsulfonyloxy, or halogen, and each of p and q is an integer of 1 to 3.

Non-aqueous electrolytic solution and lithium secondary battery

In a rechargeable non-aqueous electrolyte secondary battery using positive electrodes, negative electrodes and a non-aqueous electrolytic solution, additives to the electrolytic solution are used in combination, preferably in combination of at least two compounds selected from o-terphenyl, triphenylene, cyclohexylbenzene and biphenyl, and thus there are provided batteries excellent in safety and storage characteristics.

Electrolyte for non-aqueous cell and non-aqueous secondary cell

A method of increasing the discharge capacity retention of a non-aqueous lithium ion secondary battery having a positive electrode active material, a combination of a lithium element and a complex metal oxide, a negative electrode, and a non-aqueous electrolytic solution comprising an electrolyte dissolved in a non-aqueous solvent which is a combination of a cyclic carbonate and a linear carbonate by incorporating a disulfide derivative having the formula:R&#x2014;S&#x2014;S&#x2014;Rwherein each of Rand Rindependently represents a phenyl group, a benzyl group, a tolyl group, a pyridyl group, a pyrimidyl group, an alkyl group having 1 to 12 carbon atom, or a cycloalkyl group having 3 to 6 carbon atoms, in which each group has no substituent groups or has one or more alkyl groups into the non-aqueous electrolytic solution.

Non-aqueous secondary battery having increased discharge capacity retention

A non-aqueous electrolyte containing propylene carbonate and 1,3-propanesultone as additives can reduce the amount of a gas evolved during storage at a high temperature of a non-aqueous electrolyte secondary cell comprising the electrolyte, a non-aqueous electrolyte containing at least one compound selected from the group consisting of vinylene carbonate, diphenyl disulfide, di-p-tolydisulfide and bis(4-methoxyphenyl)disulfide as comprising the electrolyte, and a non-aqueous electrolyte containing a combination of the above-two types of additives can provide a non-aqueous electrolyte secondary cell exhibiting excellent retention of capacity and storage stability.

Non-aqueous electrolyte and non-aqueous electrolyte secondary battery

A non-aqueous electrolytic solution composed of two or more organic compounds dissolved in a solvent composed of a cyclic carbonate and a chain carbonate, in an amount of 0.01 to 8 weight % for each compound, in which both of the two organic compounds have a reduction potential higher than those of the cyclic and chain carbonates, and in which one of the organic compounds has a reduction potential equal to that of another organic compound or has a reduction potential lower or higher than that of another organic compound by a potential of less than 0.4 V is favorably employable for a non-aqueous secondary battery.

A nonaqueous electrolytic solution for lithium secondary batteries. When the nonaqueous solvent comprises a combination of an ester of a tertiary carboxylic acid and a cyclic carbonate such as propylene carbonate or ethylene carbonate, a lithium salt having a fluorine atom is preferably used as the electrolyte salt. In this case, the ester of a tertiary carboxylic acid is preferably used in a relatively small amount, especially in an amount of about 0.5 to 35 wt. % based on the nonaqueous solvent.

Nonaqueous electrolytic solution and lithium secondary battery

A discharge capacity retention of a non-aqueous secondary battery is enhanced by incorporating into its non-aqueous electrolytic solution a small amount of a substituted diphenyldisulfide derivative in which each of the diphenyl groups has a substituent such as alkoxy, alkenyloxy, alkynyloxy, cycloalkyloxy, aryloxy, acyloxy, alkanesulfonyloxy, arylsulfonyloxy, alkoxycarbonyloxy, aryloxycarbonyloxy, halogen, CF, CCl, or CBr. Preferably, a small amount of methyl 2-propylcarbonate, 2-propynyl methanesulfonate, 1,3-propanesultone, divinylsulfone, 1,4-butanediol dimethanesulfonate or cyclohexylbenzene is further incorporated.

Non-aqueous secondary battery having enhanced discharge capacity retention

An electrolysis solution for electrolytic capacitors including an aqueous organic solvent consisting of water and a water-compatible organic solvent and 1,6-decane-dicarboxylic acid or salt thereof dissolved therein. The solution further contains one or more additives selected from dinitriles, pivalic acid and salts thereof, diesters, alkylated lactones, cyanoalkanoic esters, monocarbboxylic acids each having a C alkyl chain and substituted with two C alkyl groups at the &bgr;-position to the carboxyl group and salts thereof, monocarboxylic acids each having C alkyl chain and substituted with one ethyl group at the &agr;-position to the carboxyl group and salts thereof, and monocarboxylic acids derived from cyclic saturated compounds each having five or six ring-constituting carbon atoms and salts thereof. When one or more compounds selected from among dinitriles, diesters, alkylated lactones and cyanoalkanoic esters are used as the additives, the 1,6-decanedicarboxylic acid may be replaced by other carboxylic acid.

Electrolysis solution for electrolytic capacitors

A non-aqueous electrolyte comprising a non-aqueous solvent and a lithium salt dissolved therein, and a cyclic carbonate, linear carbonate, and vinylene carbonate having a chlorine content of 100 ppm or less, and a lithium secondary battery using the same.

An electrode material for a secondary cell comprising as its essential component a powder of graphite having a crystallinity of 90% or more obtained by graphitizing a highly heat resistant polymer compact in an anaerobic atmosphere and crushing into a powder, and a process for the production of an electrode material for a secondary cell comprising heating and graphitizing a composition in which 0-10 wt % of a boron compound is added to a highly heat-resistant polymer to produce a powder of graphite having crystallinity of 90% or more contained as its essential component. An electrode material for a secondary cell having excellent charge/discharge cycle life and discharge voltage performance is provided.

Electrode material for a secondary cell and its production process

A non-aqueous electrolytic solution favorably employable for a lithium secondary battery employs a non-aqueous solvent composed of a cyclic carbonate, a linear carbonate and vinylene carbonate, and shows a reduction potential of less than 1 volt, with reference to lithium, or contains chlorine atom-containing organic compounds in an amount of 10 ppm or less, in terms of chlorine atom content.

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Yamaguchi, Japan

Toshikazu Hamamoto