Hitachi, Ltd.

Japan Science and Technology Corporation

Shizuoka University

Ricoh Company, Ltd.

Yasutaka Tanaka

Naoto Abe

Shin Takahashi

Hiroshi Haruna

Toshio Abe

Yoshio Itoh

Tatsuo Fujinami

Kazushige Kohno

Tatsuya Dan

Yuka Araki

Shuhei Takeshita

Hiroshi Suzuki

Yasutoshi Iriyama

Akiyoshi Torii

Akemi Sekita

Provided are a lithium secondary battery having improved initial capacity and excellent cycle property, an electrolyte solution for the lithium secondary battery, and an additive for the electrolyte solution for the lithium secondary battery. The lithium secondary battery includes positive and negative electrodes both having a lithium-ion intercalation/de-intercalation ability, and a non-aqueous electrolyte solution contacted with the positive and negative electrodes. The non-aqueous electrolyte solution contains lithium hexafluorophosphate and a boroxine compound represented by (RO)(BO)liquefying at 25&#xb0; C. R(s) each independently represent an organic group of a linear chain alkyl group having 3 or more carbon atoms. Herein, the chain alkyl group may have a branch, and when the branch is included, the number of carbon atoms of the chain alkyl group constructing a linear portion thereof is 3 or more.

Lithium secondary battery, electrolyte solution for lithium secondary battery, and additive for electrolyte solution therefor

Disclosed is an electrolyte solution used for a lithium secondary battery having high capacity, less undergoing aging deterioration of capacity, and also excellent in life characteristic. The electrolyte solution used for a lithium secondary battery contains a compound having a trivalent or higher boron formed by incorporation of a boroxine compound represented by (RO)(BO)in which R(s) each represent independently an organic group of 1 to 6 carbon atoms and LiPF, and a non-aqueous solvent.

Electrolyte solution for lithium secondary battery and lithium secondary battery

The invention provides a solvent for an electrolyte solution, an electrolyte solution, and a gel-like electrolyte superior in oxidation resistance and flame resistance. A solvent for an electrolyte solution comprising at least one boric ester represented by the following formula (I), and a boric ester represented by the following formula (II): B(OR)(I); B(OCHCHCN)(II) wherein, in formula (I), each Rindependently represents CH(CF)nCFor CH(CF), n is an integer from 0 to 6, and at least a part of each of &#x2014;ORf and &#x2014;OCHCHCN included in the boric esters is transesterified.

Solvent for electrolyte solution, electrolyte solution, and gel-like electrolyte

Disclosed are aromatic condensation compounds useful as building blocks for construction of various types of optically active substances and reagent, wherein the aromatic condensation compounds are represented by general formula (1) below and capable of forming enantiomeric isomers. In the formula, two Rs are the same or different functional groups and selected from among linear, branched and cyclic hydrocarbon groups of 1-16 carbon atoms, either of which R may be hydrogen. A portion of the aromatic nucleus may be reduced, or at least one of the two nitrogen atoms may be quaternary. The aromatic condensation compounds can be produced by heating and reacting N,N'-diphenyl-p-phenylenediamine with a carboxylic acid represented by the general formula --RCOOH in an amount of at least 2 molar equivalents with respect to the diamine, at 180-210.degree. C. in the presence of a Lewis acid such as zinc chloride. ##STR1##

Aromatic condensation compounds useful as optically active building

Growing community of inventors

Hamamatsu, Japan

Yasutaka Tanaka