Daikin Industries, Ltd.

Tomoyo Sanagi

Meiten Koh

Hideo Sakata

Hitomi Nakazawa

Akiyoshi Yamauchi

Akinori Tani

Aoi Nakazono

Kyouhei Sawaki

Yuki Adachi

Masahiro Tomita

Hiroyuki Arima

Toshiki Ichisaka

Kenzou Takahashi

Mayuko Taeda

Michiru Kagawa

Tani Akinori

The present invention provides a lithium ion secondary cell excellent in high-temperature storage characteristics and high voltage cycle characteristics; and a nonaqueous electrolyte for the cell. The present invention relates to a lithium ion secondary cell, comprising a positive electrode, a negative electrode, and a nonaqueous electrolyte containing nonaqueous solvents and an electrolyte salt, the nonaqueous solvents comprising a fluorine-containing ether represented by the formula (1):Rf&#x2014;O&#x2014;Rf&#x2003;&#x2003;(1)wherein Rfand Rfare the same as or different from each other, each being a Calkyl group or a Cfluoroalkyl group; and at least one of Rfand Rfis a fluoroalkyl group, and the following compounds (I) and (II): (I) a fluorine-containing unsaturated compound; and (II) a hydroxy group-containing compound represented by the formula (2):RfOH&#x2003;&#x2003;(2)wherein Rfis the same as above, and the nonaqueous solvents comprising the compounds (I) and (II) in a total amount of 5000 ppm or less for the fluorine-containing ether.

Lithium ion secondary battery and nonaqueous electrolyte for lithium ion secondary battery

The present invention aims to provide an electrochemical device excellent in high temperature storage characteristics and cycling characteristics at high voltages, and a nonaqueous electrolyte for the electrochemical device. The present invention relates to an electrochemical device including: a positive electrode; a negative electrode; and a nonaqueous electrolyte containing a nonaqueous solvent and an electrolyte salt, wherein the nonaqueous solvent contains a fluorinated linear carbonate represented by the formula (1):RfOCOOR&#x2003;&#x2003;(1)(wherein Rf represents a C1-4 fluorinated alkyl group and R represents a C1-4 alkyl group), and further contains following compounds of (I) to (III) in a total amount of not more than 5000 ppm relative to the fluorinated linear carbonate: (I) a compound represented by the formula (2)RfOH&#x2003;&#x2003;(2)(wherein Rf is defined as above); (II) a compound represented by the formula (3)ROH&#x2003;&#x2003;(3)(wherein R is defined as above); and (III) a compound represented by the formula (4)ROCOCl&#x2003;&#x2003;(4)(wherein R is defined as above).

Electrochemical device and nonaqueous electrolyte solution for electrochemical device

Provided is an electrolytic solution exhibiting excellent withstand voltage and satisfactory characteristics even at low and high temperatures. The invention is an electrolytic solution that includes a cyclic carbonate (I-1) represented by formula (I-1): (in the formula, R is an alkyl group having two or more carbon atoms, a fluorine-containing alkyl group having two or more carbon atoms, an alkoxy group or a fluorine-containing alkoxy group, in which an oxygen atom may be inserted between carbon atoms); a cyclic carbonate (I-2) different from the cyclic carbonate (I-1); and an electrolyte salt (II)).

Electrolytic solution

The present invention directs to a non-aqueous electrolyte solution, including (I) at least one compound selected from the group consisting of fluorinated linear sulfones and fluorinated linear sulfonic acid esters, and (II) an electrolyte salt. Such a non-aqueous electrolyte solution has high oxidation resistance, minimizes its decomposition even when hydrofluoric acid is produced. Also, the solution is less likely to cause, in the case of being used for a secondary cell, swelling of the cell and lowering of the battery performance.

Non-aqueous electrolyte solution

The present invention provides a conductive protective layer-forming paste for current collector laminates which can be used even for high voltage designs to protect current collectors from corroding without loss of cell characteristics, and a current collector laminate, an electrode laminate, and nonaqueous secondary cells (e.g. a lithium secondary cell, an electric double layer capacitor) that include a conductive protective layer formed therefrom. The paste for forming conductive protective layers for current collector protection includes: polytetrafluoroethylene; and a conductive filler (b). The current collector laminate includes: a conductive protective layer (A); and a current collector (B), the conductive protective layer (A) being formed by coating the paste for forming conductive protective layers onto the current collector (B).

Paste for forming conductive protection layer on collector laminate in non-aqueous rechargeable electricity-storage device

The present invention provides a solvent for a nonaqueous electrolyte solution enabling a lithium secondary battery to exhibit an excellent discharge capacity, load characteristics, and cycle characteristics even under high voltages, as well as a nonaqueous electrolyte solution that uses this solvent and a lithium secondary battery. This solvent for a nonaqueous electrolyte solution is a solvent for a nonaqueous electrolyte solution for a lithium secondary battery, wherein the solvent for a nonaqueous electrolyte solution contains a fluorine-free cyclic carbonate (I), a fluorine-free chain carbonate (II), and a 1,1-di(fluorinated alkyl)ethylene carbonate (III), and wherein with a sum of (I), (II), and (III) being 100 volume %, the fluorine-free cyclic carbonate (I) is 10 to 50 volume %, the fluorine-free chain carbonate (II) is 49.9 to 89.9 volume %, and the 1,1-di(fluorinated alkyl)ethylene carbonate (III) is from at least 0.1 volume % to not more than 30 volume %.

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Moriguchi, Japan

Tomoyo Sanagi