Gs Yuasa International Ltd.

Masashi Takano

Tomonori Kako

Akihiko Miyazaki

Taro Yamafuku

Kazuki Kawaguchi

Masaki Masuda

Ukyo Harinaga

Sumio Mori

Kenta Nakai

Kenta Uehira

An aspect of the present invention is a nonaqueous electrolyte energy storage device including: a positive electrode having a positive composite layer including a positive active material; a negative electrode having a negative composite layer including a negative active material; and a nonaqueous electrolyte including a nonaqueous solvent, in which the positive active material includes a lithium-transition metal composite oxide that contains nickel as a transition metal and has a layered α-NaFeO-type crystal structure, a ratio (N/P) between mass (N) per unit area of the negative active material and mass (P) per unit area of the positive active material is 0.30 or more and 0.45 or less, the nonaqueous solvent contains PC, DEC, and EMC, a content of the PC in the nonaqueous solvent is 25% by volume or more and 55% by volume or less, a total content of the DEC and the EMC in the nonaqueous solvent is 45% by volume or more and 75% by volume or less, and a content of the DEC is equal to or higher than the content of the EMC.

Nonaqueous electrolyte energy storage device and energy storage apparatus

The present embodiment provides a lithium ion secondary battery including a positive electrode containing LiNiCoMO(0.9&#x2264;a&#x2264;1.2, 0.3&#x2264;x&#x2264;0.8, 0.2&#x2264;y+z&#x2264;0.7, where M is a metal element other than Li, Ni, and Co) as a positive active material, and a negative electrode containing non-graphitic carbon as a negative active material. In this lithium ion secondary battery, at a portion where the positive electrode and the negative electrode face each other, a basis weight (P) of the positive active material and a basis weight (N) of the negative active material satisfy a relational expression of 0.65&#x2264;P/N&#x2264;1.05.

Lithium ion secondary battery

An energy storage device includes a negative electrode having a negative active material layer containing amorphous carbon as an active material, a curve attained by determining a rate of change (dQ/dV) in a potential (V) of the amorphous carbon in a discharge capacity (Q) of the amorphous carbon per unit quantity based on a result attained by measuring the potential (V) with respect to the discharge capacity (Q) and representing the rate of change (dQ/dV) with respect to the potential (V) has one or more peaks in a range in which the potential of the amorphous carbon is 0.8 V or more and 1.5 V or less, and a potential of the negative electrode at time of full charge is 0.25 V or more with respect to a lithium potential.

Energy storage device and energy storage apparatus

There is provided is an energy storage device having improved power performance at a relatively large current. In the present embodiment, an energy storage device is provided, which has a negative active material layer containing particulate amorphous carbon, wherein a distribution curve of differential pore volume in the negative active material layer has a peak appearing within the range from 0.1 &#x3bc;m to 2 &#x3bc;m inclusive and the differential pore volume at the peak is 0.9 cm/g or more.

Energy storage device and method for producing same

According to an embodiment of the present invention, deterioration of a non-aqueous electrolyte power storage element is detected based on a first increase rate and a second increase rate, the first increase rate being an increase rate of a direct current resistance value obtained by measuring the non-aqueous electrolyte power storage element over a first time period, the second increase rate being an increase rate of a direct current resistance value obtained by measuring the non-aqueous electrolyte power storage element over a second time period that is longer than the first time period.

Deterioration detector for non-aqueous electrolyte power storage element, power storage device, deterioration detection system for non-aqueous electrolyte power storage element, and deterioration detection method for non-aqueous electrolyte power storage element

An energy storage device includes: a first guide portion which is arranged in the inside of a case and allows an electrolyte solution to flow toward one end of an electrode assembly in a winding axis direction from an electrolyte solution pouring hole; and a second guide portion which is arranged in the inside of the case and allows a fluid to flow toward the electrolyte solution pouring hole from the inside of the case, and which prevents the electrolyte solution from flowing toward the other end of the electrode assembly in the winding axis direction from the electrolyte solution pouring hole or suppresses the electrolyte solution from flowing toward the other end of the electrode assembly in the winding axis direction from the electrolyte solution pouring hole.

Growing community of inventors

Kyoto, Japan

Masashi Takano