Nec Corporation

Nec Energy Devices, Ltd.

Nec C Orporation

Daisuke Kawasaki

Kazuaki Matsumoto

Yoko Hashizume

Jiro Iriyama

Tatsuji Numata

Midori Shimura

Masahiro Suguro

Ikiko Shimanuki

Takehiro Noguchi

Tetsuya Kajita

Noboru Yoshida

Hitoshi Ishikawa

Takuya Hasegawa

Ryuichi Kasahara

Kazuhiko Inoue

Hiroo Takahashi

Kazuhiko Isoyama

Kenichi Shimura

Takahiro Ohkuma

Shinako Kaneko

Shin Serizawa

Takashi Ohtsuka

Suguru Tamai

Emiko Fujii

Koji Utsugi

Yuukou Katou

Shinya Sudo

Shinsaku Saitho

Makiko Uehara

Yuki Kusachi

Akinobu Nakamura

Tomokazu Kumeuchi

Junya Nakamura

Arata Toyoda

Kaori Yamane

Takehiro Hokimoto

A display control method includes: acquiring information indicating a contact point of an attendant in a train from a management device storing the information indicating the contact point of the attendant in the train; and transmitting information for causing a display device in the train to display a two-dimensional code based on the acquired information.

Display control device, display control system, display control method, and recording medium

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

Provided is a lithium ion secondary battery having high energy density and excellent cycle characteristics. The present invention relates to a negative electrode for a lithium ion secondary battery comprising: (i) a negative electrode mixture layer comprising a negative electrode active material and a negative electrode binder and (ii) a negative electrode current collector, wherein the negative electrode active material comprises an alloy comprising silicon (Si alloy), the Si alloy is crystalline and has a median diameter (D50 particle size) of 1.2 &#x3bc;m or less, and an amount of the negative electrode binder based on the weight of the negative electrode mixture layer is 12% by weight or more and 50% by weight or less.

Negative electrode for lithium ion secondary battery and lithium ion secondary battery comprising the same

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 present invention relates to a lithium secondary battery having a positive electrode comprising a positive electrode active material capable of absorbing and releasing lithium ions, a negative electrode comprising a negative electrode active material capable of absorbing and releasing lithium ions, and an electrolyte solution, wherein a positive electrode surface detection component comprises at least one negative secondary ion peak selected from CHSOand CHSO, and further comprises a negative secondary ion peak of SO&#x2014;, wherein the positive electrode surface detection component is detected when a primary ion is irradiated on the surface of the positive electrode active material by a Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) method. According to the present invention, it is possible to provide a lithium secondary battery having excellent cycle characteristics.

Lithium secondary battery and manufacturing method therefor

When the particle size of a silicon material used for a negative electrode active material are small, a large surface area thereof easily causes a side reaction between the active material and an electrolyte solvent to occur, and the cycle characteristics of a lithium ion secondary battery decrease. In order to improve the cycle characteristics, a lithium ion secondary battery according to the present invention is characterized in comprising a negative electrode comprising a material comprising silicon as a constituent element and a polyacrylic acid, and an electrolyte solution comprising a fluoroethylene carbonate, wherein the 50% particle size of the material comprising silicon as a constituent element is 2 &#x3bc;m or less.

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

A negative electrode active material constituting a lithium ion secondary battery having high energy density and excellent cycle characteristics, and a negative electrode and a lithium ion secondary battery comprising the same are provided. The present invention relates to a negative electrode active material comprising graphite particles and crystalline silicon particles, wherein a median diameter of the crystalline silicon particles is 0.7 &#x3bc;m or less, and a weight ratio of the crystalline silicon particles to the total weight of the graphite particles and the crystalline silicon particles is 1 wt % or more and 25 wt % or less.

Negative electrode active material and lithium ion secondary battery using the same

The present invention relates to a lithium ion secondary battery comprising a positive electrode having a coating amount per unit area of 50 mg/cmor more and an electrode density of 3.3 g/cc or more and a negative electrode having a coating amount per unit area of 24 mg/cmor more and an electrode density of 1.5 g/cc or more, a separator having a shrinking ratio of 2% or less by heat treatment at 80&#xb0; C. for 6 hours, and an electrolyte solution comprising at least one sulfonic acid ester compound, and a ratio of a sulfur content in the central portion (As) and a sulfur content in the edge portion (Bs) of the positive electrode and the negative electrode, in each, is 0.7&#x2264;As/Bs&#x2264;1.1.

Lithium ion secondary battery and method for manufacturing same

An exemplary embodiment of the present invention is a secondary battery which comprises a negative electrode and a battery electrolyte liquid comprising a supporting salt and a non-aqueous electrolyte solvent; wherein the negative electrode is obtained by pre-forming a SEI coating film on a negative electrode structure which is formed by binding a negative electrode active substance comprising a metal (a). that can be alloyed with lithium, a metal oxide (b) that can absorb and desorb lithium ion and a carbon material (c) that can absorb and desorb lithium ion, to a negative electrode current collector with a negative electrode binder, and wherein the non-aqueous electrolyte solvent contains at least an ionic liquid.

Secondary battery and method for manufacturing same

It is an object of the present invention to provide an electrolytic solution capable of suppressing gas generation. The present exemplary embodiment is an electrolytic solution comprising a supporting salt, a nonaqueous solvent that dissolves the supporting salt, a cyclic sulfonic acid ester compound represented by predetermined formula (1), and an acid anhydride. According to the exemplary embodiment, an electrolytic solution capable of suppressing gas generation can be provided.

Electrolytic solution and secondary battery

A negative electrode active material comprising silicon oxide satisfying the following Equation 1 and Equation 2 when solid state NMR (Si-DDMAS) of silicon is measured for the silicon oxide after performing charging at least once is excellent in the performance as a negative electrode active material for a lithium secondary battery;0.42&#x2264;1/(1+2+3)&#x2264;0.55&#x2003;&#x2003;(Equation 1)0.21&#x2264;3/(1+2+3)&#x2264;0.26,&#x2003;&#x2003;(Equation 2)in which S1 is a sum of peak areas of a group of signals assigned to Si having a Si&#x2014;Si bond and having peaks at 0 to &#x2212;15 ppm, &#x2212;55 ppm, &#x2212;84 ppm and &#x2212;88 ppm, S2 is a sum of peak areas of a group of signals assigned to Si having a Si(OH)(OSi)(n=3, 4) structure and having peaks at &#x2212;100 ppm and &#x2212;120 ppm, and S3 is a sum of peak areas of a group of signals assigned to Si having a Si(OLi)(OSi)(n=0, 1, 2, 3) structure and having peaks at &#x2212;66 ppm, &#x2212;74 ppm, &#x2212;85 ppm and &#x2212;96 ppm.

Negative electrode active material, method for manufacturing same, and lithium secondary battery

Disclosed is an electrolyte solution for lithium secondary batteries, including a cyclic sulfonic acid ester represented by the general formula (1): wherein, in the general formula (1), Rand Reach independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, halogen or an amino group with the proviso that Rand Rdo not represent hydrogen atoms at the same time; and Rrepresents methylene which may be substituted with fluorine. Batteries using this electrolyte solution are excellent in battery properties and storage characteristics.

Electrolyte solution for secondary batteries, and secondary battery using same

A nonaqueous electrolyte solution secondary battery having an electrode element having a positive electrode and a negative electrode disposed so as to face each other, a nonaqueous electrolyte solution, and an outer package housing the electrode element and the nonaqueous electrolyte solution, wherein the nonaqueous electrolyte solution contains a cyclic sulfonic acid ester represented by the general formula (1), and a positive electrode active material in the positive electrode is a mixture of a lithium manganese composite oxide having a spinel structure and a lithium transition metal composite compound having a layered rock salt structure. wherein, in the formula (1), Rand Rare each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen group or an amino group with the proviso that Rand Rare not hydrogen atoms at the same time; Rrepresents a linkage group selected from the group consisting of an alkylene group having 1 to 5 carbon atoms, a carbonyl group, a sulfonyl group, a fluoroalkylene group having 1 to 6 carbon atoms, and a divalent group having 2 to 6 carbon atoms in which alkylene units or fluoroalkylene units are bonded through an ether group.

Growing community of inventors

Tokyo, Japan

Daisuke Kawasaki