Abstract: 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.

Abstract: 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.

Abstract: A secondary battery includes an outer package member and a battery device. The outer package member has a top part and a bottom part. The top part has a through hole extending in a first direction. The bottom part is disposed to be opposed to the top part in the first direction. The battery device is contained inside the outer package member. The battery device includes a stacked body. The stacked body includes a first electrode and a second electrode, and is wound around an internal space extending in the first direction. The battery device includes an outer wind part and an inner wind part. The outer wind part is sandwiched between the top part and the bottom part in the first direction. The inner wind part is located between the internal space and the outer wind part, and opposed to the through hole in the first direction.

Abstract: 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.

Abstract: 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.

Abstract: A battery comprising a positive electrode; a negative electrode including a negative electrode active material layer that is formed on at least one surface of a negative electrode collector; and an electrolyte, wherein in the negative electrode active material layer from the negative electrode collector up to ½ of a layer thickness in a surface direction of the negative electrode active material layer, a pore volume ratio expressed as (pore volume B/pore volume A) that is a ratio of a pore volume A (ml/g) in a range of 0.001 ?m or more and 0.4 ?m or less of a pore diameter measured by a mercury porosimeter and a pore volume B (ml/g) in a range of 0.4 ?m or more and 10 ?m or less of the pore diameter is 1.4 or more and 3.4 or less.

Abstract: A battery comprising a positive electrode; a negative electrode including a negative electrode active material layer that is formed on at least one surface of a negative electrode collector; and an electrolyte, wherein in the negative electrode active material layer from the negative electrode collector up to ½ of a layer thickness in a surface direction of the negative electrode active material layer, a pore volume ratio expressed as (pore volume B/pore volume A) that is a ratio of a pore volume A (ml/g) in a range of 0.001 ?m or more and 0.4 ?m or less of a pore diameter measured by a mercury porosimeter and a pore volume B (ml/g) in a range of 0.4 ?m or more and 10 ?m or less of the pore diameter is 1.4 or more and 3.4 or less.

Abstract: A battery includes a positive electrode, a negative electrode where a negative electrode active material layer containing a negative electrode active material containing natural graphite is formed on at least one surface of a negative electrode collector, and an electrolyte. A thickness of the negative electrode active material layer per one surface of the negative electrode collector is 50 ?m or more and 100 ?m or less, and in the negative electrode active material layer from the negative electrode collector up to ½ of the thickness of the layer in a surface direction of the negative electrode active material layer, an orientation degree A expressed as (peak intensity of carbon 002 face/peak intensity of carbon 110 face) that is a peak intensity ratio of a carbon 002 face and a carbon 110 face measured by an X-ray diffraction is 100 or more and 500 or less.

Abstract: A battery includes a positive electrode, a negative electrode where a negative electrode active material layer containing a negative electrode active material containing natural graphite is formed on at least one surface of a negative electrode collector, and an electrolyte. A thickness of the negative electrode active material layer per one surface of the negative electrode collector is 50 ?m or more and 100 ?m or less, and in the negative electrode active material layer from the negative electrode collector up to ½ of the thickness of the layer in a surface direction of the negative electrode active material layer, an orientation degree A expressed as (peak intensity of carbon 002 face/peak intensity of carbon 110 face) that is a peak intensity ratio of a carbon 002 face and a carbon 110 face measured by an X-ray diffraction is 100 or more and 500 or less.