Murata Manufacturing Co., Ltd.

Keitaro Kitada

Takaaki Matsui

Yuta Hirano

Taichi Kogure

Kazuki Honda

Futoshi Sato

Shinji Hatake

Yoshifumi Shimizu

Naoko Yamakawa

Takashi Sato

Masayuki Iwama

Taichi Katsumoto

Masahiro Miyamoto

Moriaki Okuno

Asuki Yanagihara

Takashi Fujinaga

Yoshihide Nagata

Takatoshi Munaoka

Kenji Matsubara

Takeshi Morozumi

Yuko Ohtaniuchi

Takuma Kawahara

Aya Mashiko

Aiko Kanazawa

Nobuyuki Nagaoka

Masahiro Kikkawa

A secondary battery includes a positive electrode, a negative electrode, and an electrolytic solution. The positive electrode includes a positive electrode active material layer including a lithium-cobalt composite oxide. The lithium-cobalt composite oxide has a layered rock-salt crystal structure. The negative electrode includes a negative electrode active material layer including graphite. When the secondary battery is charged and discharged with an upper limit of a closed circuit voltage being set to 4.42 V or higher, a unit capacity (mAh/g) satisfies a condition represented by 168 mAh/g≤unit capacity (mAh/g)≤(−0.28×area rate (%)+178) mAh/g.

Secondary battery

A secondary battery includes a positive electrode, a negative electrode, and an electrolytic solution. The positive electrode includes a lithium-cobalt composite oxide having a layered rock-salt crystal structure. The negative electrode includes graphite. An open circuit potential of the negative electrode measured in a full charge state is from 19 mV to 86 mV. A potential variation of the negative electrode is greater than or equal to 1 mV when the secondary battery is discharged from the full charge state by a capacity corresponding to 1% of a maximum discharge capacity. The maximum discharge capacity is obtained when the secondary battery is discharged with a constant current from the full charge state until the closed circuit voltage reaches 3.00 V, following which the secondary battery is discharged with a constant voltage of the closed circuit voltage of 3.00 V for 24 hours.

A secondary battery includes a positive electrode, a negative electrode, and an electrolytic solution. The positive electrode includes a lithium-cobalt composite oxide having a layered rock-salt crystal structure. The negative electrode includes graphite. A potential variation of the positive electrode is greater than or equal to 2 mV when the secondary battery is discharged from a full charge state by a capacity corresponding to 1% of a maximum discharge capacity. The maximum discharge capacity is a discharge capacity obtained when the secondary battery is discharged with a constant current from the full charge state until the closed circuit voltage reaches 3.00 V, following which the secondary battery is discharged with a constant voltage of the closed circuit voltage of 3.00 V for 24 hours.

A secondary battery includes: a cathode and an anode opposed to each other with a separator in between; an electrolyte layer provided between the anode and the separator; and an adhesion layer provided between the anode and the electrolyte layer, wherein the anode includes an active material and a first polymer compound, the electrolyte layer includes an electrolytic solution and a second polymer compound, the adhesion layer includes a third polymer compound, the first polymer compound includes a polar group, the second polymer compound includes a polymer chain, and the third polymer compound includes a polar group and a polymer chain same as the polymer chain of the second polymer compound.

Secondary battery, battery pack, and electric vehicle

A secondary battery includes a cathode, an anode including an active material, and non-aqueous electrolytic solution. The active material includes a center portion and a covering portion provided on part or all of the center portion. The center portion includes silicon, tin, or both as constituent elements. The covering portion includes a plurality of fibrous carbon materials. Part or all of the fibrous carbon materials extend in a direction along a surface of the center portion and are closely attached to the center portion.

Active material, method of manufacturing active material, electrode, and secondary battery

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Kanagawa, Japan

Keitaro Kitada