Hitachi, Ltd.

Hitachi Vehicle Energy, Ltd.

Hitachi Chemical Company, Ltd.

Takahiro Yamaki

Toyotaka Yuasa

Takefumi Okumura

Yoshimi Yanai

Masanori Yoshikawa

Yasuhisa Aono

Yasushi Muranaka

Seiji Takeuchi

Junya Kaneda

Jun Kawaji

Masanari Oda

Noriyuki Watanabe

Provided are a cathode active material with excellent high-temperature life that suppresses the elution of metal elements from the cathode active metal and the generation of different phase therein and exhibits a high potential, as well as a high-voltage lithium ion battery that achieves excellent high-temperature life by applying such a cathode active material. The cathode active material for a lithium ion battery is represented by a compositional formula LiNiMnMOF(where M is one or more elements selected from the group consisting of Ti, Ge, Mg, Co, Fe, Cu, and Al, and a, x, y, z, and &#x3b4; satisfy the following formulas: 1&#x2266;a&#x3c;1.08, 0.4&#x2266;x&#x3c;0.5, 0&#x3c;z&#x2266;0.3, a+x+y+z=3, and 0&#x3c;&#x3b4;&#x2266;0.2).

Cathode active material for lithium ion battery, cathode material for lithium ion battery, and lithium ion battery

In a Li ion conductivity oxide solid electrolyte containing lithium, lanthanum, and zirconium, a part of oxygen is substituted by an element M (M=N, Cl, S, Se, or Te) having smaller electronegativity than oxygen.

Solid electrolyte and all-solid state lithium ion secondary battery

The present invention provides a lithium secondary battery which has improved safety, mainly coming from use of an electrolyte solution which is not inflammable at room temperature (20&#xb0; C.), while not deteriorating output characteristics at low temperatures and room temperature or output maintenance characteristics after storage at high temperature (50&#xb0; C.). The lithium secondary battery of the present invention, encased in a container, is provided with a cathode and an anode, both capable of storing/releasing lithium ions, a separator which separates these electrodes from each other, and an electrolyte solution containing a cyclic carbonate and a linear carbonate as solvents and a compound such as VC at composition ratios of 18.0 to 30.0%, 74.0 to 81.9% and 0.1 to 1.0%, respectively, based on the whole solvents, all percentages by volume.

Lithium secondary battery

A lithium secondary battery comprising a positive electrode, a negative electrode containing a lithium ion-storable/dischargeable negative electrode-active material and a lithium ion conductive, non-aqueous electrolytic solution or polymer electrolyte, characterized in that the negative electrode-active material comprises particles of carbonaceous material and particles of metal and metal oxide capable of enhancing lithium ion interstitial diffusibility/releasability as embedded in the particles of carbonaceous material, particles of carbonaceous materials and lithium ion interstitially diffusible/releasable particles being prepared by carbonization of a mixture thereof with MA or carbon precursor, has a high capacity and a long cycle life, and can be used in various electric appliances.

Lithium secondary battery having oxide particles embedded in particles of carbonaceous material as a negative electrode-active material

Growing community of inventors

Tokyo, Japan

Takahiro Yamaki