Electrode, secondary battery, battery pack, electric vehicle, electric power storage system, electric power tool, and electronic apparatus

An electrode comprising any one of a first lithium-containing compound and a second lithium-containing compound, wherein

• the first lithium-containing compound having a bedded salt-type crystal structure,
• the first lithium-containing compound includes one or more metal elements (M) other than lithium (Li),
• a photoelectron spectrum of oxygen 1s associated with the first lithium-containing compound and including a horizontal axis representative of a binding energy in electron volt and a vertical axis representative of a spectrum intensity, the photoelectron spectrum of oxygen 1s obtained by surface analysis with the use of X-ray photoelectron spectroscopy includes a first peak and a second peak, the first peak having an apex in a range in which binding energy is from 531 electron volts to 535 electron volts both inclusive, and the second peak having an apex in a range in which binding energy is equal to or larger than 529 electron volts and less than 531 electron volts and having spectrum intensity smaller than spectrum intensity of the first peak,
• when an atomic ratio (Co/M) of cobalt in the metal element is equal to or larger than 0.5, a ratio IB/IA between a spectrum intensity IA of the second peak and a spectrum intensity IB in the case where binding energy is 535 electron volts is larger than 1, and
• when the atomic ratio (Co/M) of cobalt in the metal element is less than 0.5, a ratio IC/IA between the spectrum intensity IA of the second peak and a spectrum intensity IC in the case where binding energy is 536 electron volts is larger than 1, wherein the second lithium-containing compound having an olivine-type crystal structure,
• a photoelectron spectrum of oxygen 1s associated with the second lithium-containing compound and including a horizontal axis representative of a binding energy in electron volts and a vertical axis representative of a spectrum intensity, the photoelectron spectrum of oxygen 1s obtained by surface analysis with the use of X-ray photoelectron spectroscopy includes a third peak and a fourth peak, the third peak having an apex in a range in which binding energy is equal to or larger than 530 electron volts and less than 533 electron volts, and the fourth peak having an apex in a range in which binding energy is from 533 electron volts to 536 electron volts both inclusive and having spectrum intensity smaller than spectrum intensity of the third peak, and
• a ratio IE/ID between a spectrum intensity ID of the third peak and a spectrum intensity IE of the fourth peak is larger than ¼;
• wherein the electrode includes an electrode active material layer and a coat provided on the electrode active material layer;
• wherein the photoelectron spectrum of oxygen 1s associated with the first lithium-containing compound and the photoelectron spectrum of oxygen 1s associated with the second lithium-containing compound are obtained by surface analysis of the coat;
• wherein the coat includes a polymer compound;
• wherein the polymer compound includes a repeating unit that includes oxygen;
• and
• wherein the polymer compound includes a carbonic acid bond (—O—C(═O)—O—) in the repeating unit.

A battery pack comprising:

• a secondary battery;
• a control section configured to control operation of the secondary battery;
• and
• a switch section configured to switch the operation of the secondary battery according to an instruction of the control section, wherein
• the secondary battery includes a cathode, an anode, and a nonaqueous electrolytic solution, and
• the cathode includes any one of a first lithium-containing compound and a second lithium-containing compound, the first lithium-containing compound having a bedded salt-type crystal structure,
• the first lithium-containing compound includes one or more metal elements (M) other than lithium,
• a photoelectron spectrum of oxygen 1s associated with the first lithium-containing compound and including a horizontal axis representative of a binding energy in electron volt and a vertical axis representative of a spectrum intensity, the photoelectron spectrum of oxygen 1s obtained by surface analysis of the cathode with the use of X-ray photoelectron spectroscopy includes a first peak and a second peak, the first peak having an apex in a range in which binding energy is from 531 electron volts to 535 electron volts both inclusive, and the second peak having an apex in a range in which binding energy is equal to or larger than 529 electron volts and less than 531 electron volts and having spectrum intensity smaller than spectrum intensity of the first peak,
• when an atomic ratio (Co/M) of cobalt in the metal element is equal to or larger than 0.5, a ratio IB/IA between a spectrum intensity IA of the second peak and a spectrum intensity IB in the case where binding energy is 535 electron volts is larger than 1, and
• when the atomic ratio (Co/M) of cobalt in the metal element is less than 0.5, a ratio IC/IA between the spectrum intensity IA of the second peak and a spectrum intensity IC in the case where binding energy is 536 electron volts is larger than 1 wherein the second lithium-containing compound having an olivine-type crystal structure,
• a photoelectron spectrum of oxygen 1s associated with the second lithium-containing compound and including a horizontal axis representative of a binding energy in electron volt and a vertical axis representative of a spectrum intensity, the photoelectron spectrum of oxygen 1s obtained by surface analysis of the cathode with the use of X-ray photoelectron spectroscopy includes a third peak and a fourth peak, the third peak having an apex in a range in which binding energy is equal to or larger than 530 electron volts and less than 533 electron volts, and the fourth peak having an apex in a range in which binding energy is from 533 electron volts to 536 electron volts both inclusive and having spectrum intensity smaller than spectrum intensity of the third peak, and
• a ratio IE/ID between a spectrum intensity ID of the third peak and a spectrum intensity IE of the fourth peak is larger than ¼;
• wherein the cathode includes a cathode active material layer and a coat provided on the cathode active material layer;
• wherein the photoelectron spectrum of oxygen 1s associated with the first lithium-containing compound and the photoelectron spectrum of oxygen 1s associated with the second lithium-containing compound are obtained by surface analysis of the coat;
• wherein the coat includes a polymer compound;
• wherein the polymer compound includes a repeating unit that includes oxygen;
• and
• wherein the polymer compound includes a carbonic acid bond (—O—C(═O)—O—) in the repeating unit.

An electric vehicle comprising:

• a secondary battery;
• a conversion section configured to convert electric power supplied from the secondary battery into drive power;
• a drive section configured to operate according to the drive power;
• and
• a control section configured to control operation of the secondary battery, wherein
• the secondary battery includes a cathode, an anode, and a nonaqueous electrolytic solution, and
• the cathode includes any one of a first lithium-containing compound and a second lithium-containing compound, the first lithium-containing compound having a bedded salt-type crystal structure,
• the first lithium-containing compound includes one or more metal elements (M) other than lithium,
• a photoelectron spectrum of oxygen 1s associated with the first lithium-containing compound and including a horizontal axis representative of a binding energy in electron volt and a vertical axis representative of a spectrum intensity, the photoelectron spectrum of oxygen 1s obtained by surface analysis of the cathode with the use of X-ray photoelectron spectroscopy includes a first peak and a second peak, the first peak having an apex in a range in which binding energy is from 531 electron volts to 535 electron volts both inclusive, and the second peak having an apex in a range in which binding energy is equal to or larger than 529 electron volts and less than 531 electron volts and having spectrum intensity smaller than spectrum intensity of the first peak,
• when an atomic ratio (Co/M) of cobalt in the metal element is equal to or larger than 0.5, a ratio IB/IA between a spectrum intensity IA of the second peak and a spectrum intensity IB in the case where binding energy is 535 electron volts is larger than 1, and
• when the atomic ratio (Co/M) of cobalt in the metal element is less than 0.5, a ratio IC/IA between the spectrum intensity IA of the second peak and a spectrum intensity IC in the case where binding energy is 536 electron volts is larger than 1, wherein the second lithium-containing compound having an olivine-type crystal structure,
• a photoelectron spectrum of oxygen 1s associated with the second lithium-containing compound and including a horizontal axis representative of a binding energy in electron volt and a vertical axis representative of a spectrum intensity, the photoelectron spectrum of oxygen 1s obtained by surface analysis of the cathode with the use of X-ray photoelectron spectroscopy includes a third peak and a fourth peak, the third peak having an apex in a range in which binding energy is equal to or larger than 530 electron volts and less than 533 electron volts, and the fourth peak having an apex in a range in which binding energy is from 533 electron volts to 536 electron volts both inclusive and having spectrum intensity smaller than spectrum intensity of the third peak, and
• a ratio IE/ID between a spectrum intensity ID of the third peak and a spectrum intensity IE of the fourth peak is larger than ¼;
• wherein the cathode includes a cathode active material layer and a coat provided on the cathode active material layer;
• wherein the photoelectron spectrum of oxygen 1s associated with the first lithium-containing compound and the photoelectron spectrum of oxygen 1s associated with the second lithium-containing compound are obtained by surface analysis of the coat;
• wherein the coat includes a polymer compound;
• wherein the polymer compound includes a repeating unit that includes oxygen;
• and
• wherein the polymer compound includes a carbonic acid bond (—O—C(═O)—O—) in the repeating unit.

An electric power storage system comprising:

• a secondary battery;
• one or more electric devices configured to be supplied with electric power from the secondary battery;
• and
• a control section configured to control the supplying of the electric power from the secondary battery to the one or more electric devices, wherein
• the secondary battery includes a cathode, an anode, and a nonaqueous electrolytic solution, and
• the cathode includes any one of a first lithium-containing compound and a second lithium-containing compound, the first lithium-containing compound having a bedded salt-type crystal structure,
• the first lithium-containing compound includes one or more metal elements (M) other than lithium,
• a photoelectron spectrum of oxygen 1s associated with the first lithium-containing compound and including a horizontal axis representative of binding energy in electron volt and a vertical axis representative of a spectrum intensity, the photoelectron spectrum of oxygen 1s obtained by surface analysis of the cathode with the use of X-ray photoelectron spectroscopy includes a first peak and a second peak, the first peak having an apex in a range in which binding energy is from 531 electron volts to 535 electron volts both inclusive, and the second peak having an apex in a range in which binding energy is equal to or larger than 529 electron volts and less than 531 electron volts and having spectrum intensity smaller than spectrum intensity of the first peak,
• when an atomic ratio (Co/M) of cobalt in the metal element is equal to or larger than 0.5, a ratio IB/IA between a spectrum intensity IA of the second peak and a spectrum intensity IB in the case where binding energy is 535 electron volts is larger than 1, and
• when the atomic ratio (Co/M) of cobalt in the metal element is less than 0.5, a ratio IC/IA between the spectrum intensity IA of the second peak and a spectrum intensity IC in the case where binding energy is 536 electron volts is larger than 1, wherein the second lithium-containing compound having an olivine-type crystal structure,
• a photoelectron spectrum of oxygen 1s associated with the second lithium-containing compound and including a horizontal axis representative of a binding energy in electron volt and a vertical axis representative of a spectrum intensity, the photoelectron spectrum of oxygen 1s obtained by surface analysis of the cathode with the use of X-ray photoelectron spectroscopy includes a third peak and a fourth peak, the third peak having an apex in a range in which binding energy is equal to or larger than 530 electron volts and less than 533 electron volts, and the fourth peak having an apex in a range in which binding energy is from 533 electron volts to 536 electron volts both inclusive and having spectrum intensity smaller than spectrum intensity of the third peak, and
• a ratio IE/ID between a spectrum intensity ID of the third peak and a spectrum intensity IE of the fourth peak is larger than ¼;
• wherein the cathode includes a cathode active material layer and a coat provided on the cathode active material layer;
• wherein the photoelectron spectrum of oxygen 1s associated with the first lithium-containing compound and the photoelectron spectrum of oxygen 1s associated with the second lithium-containing compound are obtained by surface analysis of the coat;
• wherein the coat includes a polymer compound;
• wherein the polymer compound includes a repeating unit that includes oxygen;
• and
• wherein the polymer compound includes a carbonic acid bond (—O—C(═O)—O—) in the repeating unit.

An electric power tool comprising:

• a secondary battery;
• and
• a movable section configured to be supplied with electric power from the secondary battery, wherein
• the secondary battery includes a cathode, an anode, and a nonaqueous electrolytic solution, and
• the cathode includes any one of a first lithium-containing compound and a second lithium-containing compound, the first lithium-containing compound having a bedded salt-type crystal structure,
• the first lithium-containing compound includes one or more metal elements (M) other than lithium,
• a photoelectron spectrum of oxygen 1s associated with the first lithium-containing compound and including a horizontal axis representative of a binding energy in electron volt and a vertical axis representative of a spectrum intensity, the photoelectron spectrum of oxygen 1s obtained by surface analysis of the cathode with the use of X-ray photoelectron spectroscopy includes a first peak and a second peak, the first peak having an apex in a range in which binding energy is from 531 electron volts to 535 electron volts both inclusive, and the second peak having an apex in a range in which binding energy is equal to or larger than 529 electron volts and less than 531 electron volts and having spectrum intensity smaller than spectrum intensity of the first peak,
• when an atomic ratio (Co/M) of cobalt in the metal element is equal to or larger than 0.5, a ratio IB/IA between a spectrum intensity IA of the second peak and a spectrum intensity IB in the case where binding energy is 535 electron volts is larger than 1, and
• when the atomic ratio (Co/M) of cobalt in the metal element is less than 0.5, a ratio IC/IA between the spectrum intensity IA of the second peak and a spectrum intensity IC in the case where binding energy is 536 electron volts is larger than 1, the second lithium-containing compound having an olivine-type crystal structure,
• a photoelectron spectrum of oxygen 1s associated with second lithium-containing compound and including a horizontal axis representative of a binding energy in electron volt and a vertical axis representative of a spectrum intensity, the photoelectron spectrum of oxygen 1s obtained by surface analysis of the cathode with the use of X-ray photoelectron spectroscopy includes a third peak and a fourth peak, the third peak having an apex in a range in which binding energy is equal to or larger than 530 electron volts and less than 533 electron volts, and the fourth peak having an apex in a range in which binding energy is from 533 electron volts to 536 electron volts both inclusive and having spectrum intensity smaller than spectrum intensity of the third peak, and
• a ratio IE/ID between a spectrum intensity ID of the third peak and a spectrum intensity IE of the fourth peak is larger than ¼;
• wherein the cathode includes a cathode active material layer and a coat provided on the cathode active material layer;
• wherein the photoelectron spectrum of oxygen 1s associated with the first lithium-containing compound and the photoelectron spectrum of oxygen 1s associated with the second lithium-containing compound are obtained by surface analysis of the coat;
• wherein the coat includes a polymer compound;
• wherein the polymer compound includes a repeating unit that includes oxygen;
• and
• wherein the polymer compound includes a carbonic acid bond (—O—C(═O)—O—) in the repeating unit.

An electronic apparatus comprising a secondary battery as an electric power supply source, wherein

• the secondary battery includes a cathode, an anode, and a nonaqueous electrolytic solution, and
• the cathode includes any one of a first lithium-containing compound and a second lithium-containing compound the first lithium-containing compound having a bedded salt-type crystal structure,
• the first lithium-containing compound includes one or more metal elements (M) other than lithium,
• a photoelectron spectrum of oxygen 1s associated with the first lithium-containing compound and including a horizontal axis representative of a binding energy in electron volt and a vertical axis representative of a spectrum intensity, the photoelectron spectrum of oxygen 1s obtained by surface analysis of the cathode with the use of X-ray photoelectron spectroscopy includes a first peak and a second peak, the first peak having an apex in a range in which binding energy is from 531 electron volts to 535 electron volts both inclusive, and the second peak having an apex in a range in which binding energy is equal to or larger than 529 electron volts and less than 531 electron volts and having spectrum intensity smaller than spectrum intensity of the first peak,
• when an atomic ratio (Co/M) of cobalt in the metal element is equal to or larger than 0.5, a ratio IB/IA between a spectrum intensity IA of the second peak and a spectrum intensity IB in the case where binding energy is 535 electron volts is larger than 1, and
• when the atomic ratio (Co/M) of cobalt in the metal element is less than 0.5, a ratio IC/IA between the spectrum intensity IA of the second peak and a spectrum intensity IC in the case where binding energy is 536 electron volts is larger than 1, wherein the second lithium-containing compound having an olivine-type crystal structure,
• a photoelectron spectrum of oxygen 1s associated with the second lithium-containing compound and including a horizontal axis representative of a binding energy in electron volt and a vertical axis representative of a spectrum intensity, the photoelectron spectrum of oxygen 1s obtained by surface analysis of the cathode with the use of X-ray photoelectron spectroscopy includes a third peak and a fourth peak, the third peak having an apex in a range in which binding energy is equal to or larger than 530 electron volts and less than 533 electron volts, and the fourth peak having an apex in a range in which binding energy is from 533 electron volts to 536 electron volts both inclusive and having spectrum intensity smaller than spectrum intensity of the third peak, and
• a ratio IE/ID between a spectrum intensity ID of the third peak and a spectrum intensity IE of the fourth peak is larger than ¼;
• wherein the cathode includes a cathode active material layer and a coat provided on the cathode active material layer;
• wherein the photoelectron spectrum of oxygen 1s associated with the first lithium-containing compound and the photoelectron spectrum of oxygen 1s associated with the second lithium-containing compound are obtained by surface analysis of the coat;
• wherein the coat includes a polymer compound;
• wherein the polymer compound includes a repeating unit that includes oxygen;
• and
• wherein the polymer compound includes a carbonic acid bond (—O—C(═O)—O—) in the repeating unit.