Panasonic Corporation

Sanyo Electric Co., Ltd.

Panasonic Intellectual Property Management Co., Ltd.

Akira Nagasaki

Kazuhiro Hasegawa

Tatsuhiko Suzuki

Tetsuya Hayashi

Kaoru Inoue

Hiroshi Yoshizawa

Yusuke Fukumoto

Mikinari Shimada

Masato Fujikawa

Hideaki Fujita

Kohei Suzuki

Takashi Takeuchi

Haruya Nakai

Tsuyoshi Hatanaka

Koichi Kusagawa

Tetsu Hashimoto

Ryouichi Tanaka

Ayano Shiraga

A nonaqueous electrolyte secondary battery according to one aspect of the present invention includes an electrode assembly including a negative electrode plate and a positive electrode plate wound together via a separator; a nonaqueous electrolyte; a bottomed cylindrical exterior case accommodating the electrode assembly and the nonaqueous electrolyte; and a sealing member sealing an open end of the exterior case.

Nonaqueous electrolyte secondary batteries

A nonaqueous electrolyte secondary battery including a positive electrode plate including a positive electrode current collector and a positive electrode mixture layer, formed thereon, containing a positive electrode active material; a negative electrode plate including a negative electrode current collector and a negative electrode mixture layer, formed thereon, containing a negative electrode active material; a separator: a nonaqueous electrolyte; an outer can; and a sealing body. The positive electrode and negative electrode plates are wound with the separator there between. The positive electrode active material contains a lithium-nickel composite oxide containing cobalt and aluminum as constituent elements. The negative electrode active material contains graphite and a silicon material. The negative electrode plate includes negative electrode current collector-exposed portions, located at both ends thereof in a longitudinal direction, not covered by the negative electrode mixture layer. The negative electrode current collector-exposed portions are each connected to a negative electrode tab.

Nonaqueous electrolyte secondary battery

Disclosed is a charging method for one or more non-aqueous electrolyte secondary batteries by n steps of constant-current charging processes, where n is an integer equal to or greater than 2. The n steps include: (1) charging the secondary batteries at a current Ic(k) until a charge voltage per one battery reaches a voltage Ec(k), where k is an integer equal to or greater than 1 and equal to or smaller than n&#x2212;1; and (2) when the charge voltage per one battery reaches the voltage Ec(k), charging the secondary batteries at a current Ic(k+1) smaller than the current Ic(k) until the charge voltage per one battery reaches a voltage Ec(k+1) higher than the voltage Ec(k), in which (3) the currents Ic(k) and Ic(k+1) are set according to frequency of use or number of charge and discharge cycles of the secondary batteries.

Charging method for non-aqueous electrolyte secondary battery, and battery pack

In the present method, a non-aqueous electrolyte secondary battery is charged by repeating n+1 times a constant current charge and a subsequent constant voltage charge, where n is an integer of 1 or more. (1) An ncharge comprises charging the secondary battery at a current Ic(n) to a voltage Ec(n), and subsequently charging the secondary battery at the voltage Ec(n) until the current decreases from Ic(n) to Ic(n+1). (2) An (n+1)charge comprises charging the secondary battery at the current Ic(n+1) to a voltage Ec(n+1), and subsequently charging the secondary battery at the voltage Ec(n+1) until the current decreases from Ic(n+1) to Ic(n+2). Consequently, the charge time of the non-aqueous electrolyte secondary battery can be shortened while deterioration of the battery can be suppressed.

Charging method for non-aqueous electrolyte secondary battery by repeating a set of constant current charge and constant voltage charge and battery pack implementing the charging method

A lithium ion secondary battery which includes: a power generation element including a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte; a case accommodating the power generation element and having an opening; and a sealing plate sealing the opening of the case is charged. The sealing plate has an external terminal of the positive or negative electrode, and an internal terminal electrically connected to the positive or negative electrode. The external and internal terminals are connected to each other and have an electrical resistance therebetween of 0.1 to 2 m&#x3a9;. Two or more constant-current charging steps in each of which the secondary battery is charged at a constant charge current until a charge voltage reaches an end-of-charge voltage are performed. In the two or more constant-current charging steps, the secondary battery is subjected to constant-current charging at a current Ic() of 1 to 5 C until the charge voltage reaches a target voltage Ecs(). After the charge voltage reached the target voltage Ecs(), the secondary battery is subjected to constant-current charging at a current Ic(k) satisfying Ic(k)&#x3c;Ic() until the charge voltage reaches a target voltage Ecs(k) higher than the target voltage Ecs().

Lithium ion secondary battery charging method and battery pack

In a lithium secondary battery of the present invention, the positive electrode includes a positive electrode current collector and a positive electrode active material layer carried on the positive electrode current collector, the negative electrode includes a negative electrode current collector and a negative electrode active material layer carried on the negative electrode current collector, a heat-resistant layer is formed on the negative electrode, and an insulating tape is attached onto at least a part of the exposed portion of the positive electrode current collector that is opposite to the end of the negative electrode active material layer. Thus, by forming the heat-resistant layer on the negative electrode and attaching the insulating tape onto a part of the exposed portion of the positive electrode current collector, it is possible to efficiently provide a lithium secondary battery exhibiting high safety.

Lithium secondary battery and method for producing the same

A non-aqueous electrolyte secondary battery including a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and an electrolyte, wherein the positive electrode comprises a positive electrode active material comprising a particle of a composite oxide represented by a general formula: LiMeMLO. In the general formula, the element Me is at least one transition metal element except Ti, Mn, Y and Zr, the element M is at least one selected from the group consisting of Mg, Ti, Mn and Zn, and the element L is at least one selected from the group consisting of Al, Ca, Ba, Sr, Y and Zr, and 1&#x2266;x&#x2266;1.05, 0.005&#x2266;y&#x2266;0.1 (with a proviso that 0.005&#x2266;y&#x2266;0.5 is satisfied in the case of the element M being Mn) and 0&#x2266;z&#x2266;0.05 are satisfied. The separator includes a plurality of laminated monolayer films, the plurality of monolayer films each have a microporous structure, and a positive electrode-side monolayer film selected from the plurality of monolayer films which faces the positive electrode is made of polypropylene.

Non-aqueous electrolyte secondary battery with laminated separator

A lithium ion secondary battery including: an electrode group including a belt-like positive electrode and a belt-like negative electrode that are wound with a separator interposed therebetween; and a can with a bottom for accommodating the electrode group, wherein the positive electrode has a positive electrode current collector and a positive electrode mixture layer carried on the positive electrode current collector, the negative electrode has a negative electrode current collector and a negative electrode mixture layer carried on the negative electrode current collector, and a porous heat-resistant layer is partially provided between the separator and at least one of the positive electrode mixture layer and the negative electrode mixture layer. Since a porous heat-resistant layer is thus placed, a high performance lithium ion secondary battery capable of efficiently preventing internal short circuit due to overheating while preventing decrease in battery characteristics can be provided.

Growing community of inventors

Osaka, Japan

Akira Nagasaki