Nec Corporation

Nec Energy Devices, Ltd.

Takehiro Noguchi

Makiko Takahashi

Kazuhiko Inoue

Hitoshi Ishikawa

Yuukou Katou

Daisuke Kawasaki

Takuya Hasegawa

Kenichi Shimura

Shinako Kaneko

Hideaki Sasaki

Makiko Uehara

Tatsuji Numata

Shin Serizawa

Kazuaki Matsumoto

Ikiko Shimanuki

Yoko Hashizume

Shinsaku Saitho

Yasutaka Kono

Hiroshi Hatakeyama

Akinobu Nakamura

Emiko Fujii

Hidetoshi Tamura

Ippei Waki

A purpose of the present invention is to provide a lithium ion secondary battery having improved battery characteristics. The lithium ion secondary battery according to the present invention comprises a negative electrode comprising a negative electrode active material comprising a silicon material and an electrolyte solution comprising an electrolyte solvent comprising an open chain sulfone compound, a fluorinated cyclic carbonate and an open chain carbonate and a supporting salt comprising LiN(FSO).

Lithium ion secondary battery

A lithium ion secondary battery having high energy density and being excellent in cycle characteristics is provided. The present invention relates to a lithium ion secondary battery comprising: a negative electrode active material comprising a material comprising silicon as a constituent element; and an electrolyte solution comprising: a non-aqueous solvent comprising a fluorinated ether compound, an open-chain sulfone compound, and a cyclic carbonate compound, and a supporting salt comprising LiPF, lithium bis(fluorosulfonyl)imide, and lithium bis(oxalato)borate (LiBOB); wherein the content of LiBOB in the electrolyte solution is 0.2 mass % or more.

A purpose of one embodiment of the present invention is to provide a lithium ion secondary battery that has improved life-span characteristics. The first lithium ion secondary battery of the present invention comprises an electrolyte solution comprising a sulfone compound, a fluorinated ether compound and LiN(FSO), and a negative electrode comprising a silicon material, wherein a content of LiN(FSO)in the electrolyte solution is more than 5 weight % and 20 weight % or less.

The purpose of the present invention is to provide a lithium secondary battery which has improved service life characteristics by suppressing a decomposition reaction of the electrolyte solution in the field of batteries that operate at high voltages or are assumed to be used at high temperatures for a long period of time. The present invention relates to an electrolyte solution for a secondary, which is characterized by containing a sulfone compound, a fluorine-containing cyclic acetal compound and a cyclic carbonate in a specific composition; and a secondary battery which uses this electrolyte solution for a secondary battery.

Electrolyte solution for secondary battery and secondary battery

The object is to provide a lithium ion secondary battery which has an excellent cycle property even in high-temperature environment and which has small volume increase. An exemplary embodiment of the invention is a lithium ion secondary battery, comprising: a positive electrode, a negative electrode comprising a negative electrode active material, and an electrolyte liquid; wherein the electrolyte liquid comprises a chain-type fluorinated ester compound represented by a predetermined formula and a chain-type fluorinated ether compound represented by a predetermined formula; wherein the negative electrode active material comprises metal (a) that can be alloyed with lithium, metal oxide (b) that can absorb and desorb lithium ion, and carbon material (c) that can absorb and desorb lithium ion; and wherein metal (a) is silicon, and metal oxide (b) is silicon oxide.

Secondary battery and electrolyte liquid

The present invention relates to a positive electrode comprising a Mn composite oxide having a tetragonal structure represented by formula (1): Li(MMnY)(OZ)(wherein 1&#x3c;a&#x2264;2.6, 0&#x2264;x&#x2264;1.2, 0&#x2264;y, x+y&#x3c;2, 0&#x2264;w&#x2264;1; M is at least one selected from the group consisting of Co, Ni, Fe, Cr and Cu; Y is at least one selected from the group consisting of Li, B, Na, Mg, Al, Ti, Si, K and Ca; Z is at least one of F or Cl; and a composite oxide having a layered structure represented by formula (2): Li(LiMY)O(wherein 0&#x2264;x&#x3c;0.3, 0&#x2264;y&#x3c;0.3; M is at least one selected from the group consisting of Co, Fe, Ni and Mn; Y is at least one selected from the group consisting of Mg, Al, Zr, Ti and Zn. According to the present invention, a lithium secondary battery having a high capacity and being excellent in cycle life can be provided.

Positive electrode and secondary battery using same

The present invention provides a lithium ion secondary battery having excellent high temperature cycle characteristics. The present invention relates to an electrolyte solution containing a non-aqueous electrolyte solvent containing two or more open chain sulfone compounds represented by a specific formula and one or more carbonate ester compounds represented by a specific formula; and to a secondary battery comprising these.

Electrolyte solution for secondary battery and secondary battery using same

The present invention relates to a nonaqueous electrolyte solution comprising a nonaqueous electrolyte solvent which comprises a fluorine-containing phosphate ester represented by a specific formula, a fluorine-containing ether represented by a specific formula, and an open-chain or cyclic acid anhydride. According to the present invention, there is provided an electrolyte solution capable of realizing a lithium secondary battery having an excellent cycle characteristics with little gas generation after charge-discharge cycles.

Electrolyte solution and secondary battery using same

The present invention relates to a positive electrode for lithium ion secondary batteries, the positive electrode comprising a positive electrode active material and a positive electrode binder, in which the positive electrode active material comprises lithium manganate having a spinel structure, and the positive electrode binder comprises at least polyvinylidene fluoride (PVDF) and a resin having sulfone linkages, and to a lithium ion secondary battery comprising the positive electrode for lithium ion secondary batteries.

The present invention relates to a secondary battery electrolyte, which contains a first fluorine-containing ether compound, a second fluorine-containing ether compound, and at least one selected from fluorine-containing phosphate ester compounds and sulfone compounds, wherein the fluorine substitution rate of the first fluorine-containing ether compound is lower than that of the second fluorine-containing ether compound, and the content of the first fluorine-containing ether compound is higher than that of the second fluorine-containing ether compound. According to the present invention, with respect to batteries operating at a high voltage, and batteries supposed to be used at a high temperature for a long period, there can be provided a lithium secondary battery suppressed in the decomposition reaction of the electrolyte and improved in the life characteristics.

Secondary battery electrolyte and secondary battery

An object of the present invention is to provide a secondary battery having high energy density with long-term life. The present invention relates to a secondary battery comprising a negative electrode comprising a silicon-containing compound and an electrolyte solution comprising a fluorine-containing ether compound, a fluorine-containing phosphoric acid ester, a sulfone compound and a cyclic carbonate compound in a predetermined amount respectively.

Secondary battery

The present invention is a lithium ion secondary battery comprising a positive electrode and a non-aqueous electrolyte solution comprising a non-aqueous electrolyte solvent, wherein the positive electrode comprises a positive electrode active material having an operating potential at 4.5 V or higher versus lithium metal, the non-aqueous electrolyte solvent comprises a fluorinated phosphate ester represented by a predetermined formula and at least one selected from the group consisting of sulfone compounds represented by predetermined formulae, and the sulfone compound is included in an amount of 5 volume % or more in the non-aqueous electrolyte solvent.

An embodiment of the present invention relates to a lithium secondary battery comprising a nonaqueous electrolytic solution comprising a phosphate compound represented by the following general formula (1): O&#x2550;P(O&#x2014;R)(O&#x2014;R)(O&#x2014;R) (1), wherein R, R, and Rare each alkyl group or the like or a group comprising an ether bond represented by &#x2014;R&#x2014;O&#x2014;R(Rrepresents alkylene group, and Rrepresents alkyl group), and at least one of R, R, and Ris a group comprising an ether bond, and at least one of R, R, and Rcontains fluorine, and a positive electrode active material having a charge and discharge region of 4.5 V or more versus lithium.

Lithium secondary battery and production method therefor

A lithium secondary battery including a positive electrode including a positive electrode active material capable of intercalating and deintercalating lithium ions, a negative electrode including a negative electrode active material capable of intercalating and deintercalating lithium ions, and a nonaqueous electrolytic solution, wherein the positive electrode active material includes an active material capable of intercalating or deintercalating lithium ions at a potential of 4.5 V or more, and the nonaqueous electrolytic solution includes a particular fluorine-containing ether compound.

Nonaqueous electrolyte with fluorine containing ether compound for lithium secondary battery

A secondary battery having an improved life characteristics is provided by the use of a positive electrode active material for a secondary battery, comprising (a) a surface layer comprising a lithium metal composite oxide having a spinel crystal structure represented by space group Fd-3m, and (b) an internal portion comprising a lithium metal composite oxide having a spinel crystal structure represented by space group P432.

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Tokyo, Japan

Takehiro Noguchi