公开(公告)号：US20180151882A1

公开(公告)日：2018-05-31

申请号：US15577432

申请日：2016-05-25

Applicant: NEC Corporation

Inventor： Ikiko SHIMANUKI ,  Suguru TAMAI

IPC: H01M4/62 ,  H01M10/0525 ,  H01M10/0567 ,  H01M4/134 ,  H01M4/133 ,  H01M4/66 ,  H01M10/058

CPC classification number: H01M4/622 ,  H01M4/133 ,  H01M4/134 ,  H01M4/48 ,  H01M4/625 ,  H01M4/661 ,  H01M10/0525 ,  H01M10/0567 ,  H01M10/058 ,  H01M2220/20 ,  Y02E60/122 ,  Y02P70/54 ,  Y02T10/7011

Abstract: A lithium ion secondary battery excellent in cycle characteristics, comprising a high capacity negative electrode comprising a metal and/or a metal oxide as an active material is provided. The present invention relates to a lithium ion secondary battery comprising a positive electrode, a negative electrode, and an electrolyte solution, wherein the negative electrode comprises (a) a carbon material that can absorb and desorb lithium ions; at least one selected from the group consisting of (b) lithium metal and metals that can be alloyed with lithium and (c) metal oxides that can absorb and desorb lithium ions; and a polyacrylic acid, and the electrolyte solution comprises at least one disulfonic acid ester.

公开(公告)号：US20210210785A1

公开(公告)日：2021-07-08

申请号：US16760242

申请日：2018-10-31

Applicant: NEC CORPORATION

Inventor： Shin SERIZAWA ,  Suguru TAMAI ,  Kazuhiko INOUE

IPC: H01M10/0567 ,  H01M10/0525 ,  H01M4/62 ,  H01M4/38 ,  H01M4/583 ,  H01M4/36 ,  H01M4/525 ,  H01M4/04 ,  H01M4/66 ,  H01M10/0568

Abstract: Deterioration in cycle characteristics and battery swelling are improved. The lithium ion secondary battery of the present invention is characterized in comprising an electrolyte solution comprising a multifunctional monomer comprising two or more epoxy groups and a negative electrode comprising a binder comprising a polymer comprising a monomer unit comprising a functional group selected from the group consisting of —OH, —OM, —COOH, —COOM and —COOCnH2n+1, wherein M is a metal element, and n is an integer of 1 to 5.

公开(公告)号：US20180351203A1

公开(公告)日：2018-12-06

申请号：US15778667

申请日：2016-11-29

Applicant: NEC Corporation

Inventor： Suguru TAMAI

IPC: H01M10/0525 ,  H01M4/38 ,  H01M4/505 ,  H01M4/525 ,  H01M4/62 ,  H01M2/26 ,  H01M10/058

CPC classification number: H01M10/0525 ,  H01M2/26 ,  H01M4/134 ,  H01M4/386 ,  H01M4/485 ,  H01M4/505 ,  H01M4/525 ,  H01M4/622 ,  H01M4/623 ,  H01M4/625 ,  H01M10/052 ,  H01M10/058 ,  H01M2004/027 ,  H01M2004/028 ,  H01M2220/20

Abstract: Provided is a lithium ion secondary battery that has improved cycle characteristics and employs a silicon material as a negative electrode active material. The lithium ion secondary battery according to the present invention comprises a negative electrode comprising at least a copolymer and a material comprising silicon as a constituent element, wherein the copolymer comprises a monomer unit based on an ethylenically unsaturated carboxylic acid alkali metal salt and a monomer unit based on an aromatic vinyl and the copolymer comprises an alkali metal constituting the alkali metal salt in an amount of 1000 mass ppm or more.

公开(公告)号：US20190051928A1

公开(公告)日：2019-02-14

申请号：US16079676

申请日：2017-02-22

Applicant: NEC Corporation

Inventor： Daisuke KAWASAKI ,  Takashi OHTSUKA ,  Suguru TAMAI ,  Noboru YOSHIDA ,  Shinya SUDO

IPC: H01M10/0525 ,  H01M10/0566 ,  H01M4/583 ,  H01M4/62 ,  H01M4/38 ,  H01M10/058

Abstract: 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 μm 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.

公开(公告)号：US20210151749A1

公开(公告)日：2021-05-20

申请号：US16611927

申请日：2018-05-17

Applicant: NEC CORPORATION

Inventor： Suguru TAMAI ,  Hitoshi ISHIKAWA

IPC: H01M4/38 ,  H01M10/0525 ,  H01M10/0567 ,  H01M10/44 ,  H01M10/058

Abstract: A purpose of one embodiment of the present invention is to provide a lithium ion secondary battery which has improved cycle characteristics and comprises a Si material in the negative electrode. The lithium ion secondary battery according to the present invention comprises a negative electrode comprising a negative electrode active material, a positive electrode comprising a positive electrode active material and an electrolyte solution, wherein the negative electrode active material comprises a Si material, and a ratio (Ia/Ib) of a peak intensity (Ia) at 290 eV to a peak intensity (Ib) at 285 eV is 0.7 or more in a C1s spectrum obtained by surface analysis of the negative electrode by X-ray photoelectron spectroscopy.

公开(公告)号：US20190252716A1

公开(公告)日：2019-08-15

申请号：US16333512

申请日：2017-09-14

Applicant: NEC Corporation

Inventor： Suguru TAMAI ,  Noboru YOSHIDA

IPC: H01M10/0525 ,  H01M10/058 ,  H01M10/0567 ,  H01M4/131 ,  H01M4/485 ,  H01M4/60

CPC classification number: H01M10/0525 ,  H01M4/131 ,  H01M4/485 ,  H01M4/602 ,  H01M4/62 ,  H01M10/0567 ,  H01M10/058 ,  H01M2004/027 ,  H01M2220/20 ,  Y02E60/122 ,  Y02T10/7011

Abstract: The purpose of one embodiment of the present invention is to provide a lithium ion secondary battery which has improved cycle characteristics and the negative electrode of which comprises a silicon oxide. The present invention relates to a lithium ion secondary battery comprising a silicon oxide and an electrolyte solution comprising a fluorinated acid anhydride.

公开(公告)号：US20190173123A1

公开(公告)日：2019-06-06

申请号：US16095850

申请日：2017-05-23

Applicant: NEC CORPORATION

Inventor： Ikiko SHIMANUKI ,  Daisuke KAWASAKI ,  Hitoshi ISHIKAWA ,  Suguru TAMAI

IPC: H01M10/0525 ,  H01M4/38 ,  H01M10/0567 ,  B60L50/64

Abstract: A lithium ion secondary battery having high energy density and excellent cycle characteristics is provided. The present invention relates to a lithium ion secondary battery comprising a negative electrode comprising a negative electrode active material comprising more than 25% by weight of a silicon alloy and a non-aqueous electrolyte solution comprising more than 10% by weight of a compound represented by LiN(SO2CnF2n+1)2 (wherein n is an integer of 0 or more) and 10% by weight or more of fluoroethylene carbonate (FEC).

公开(公告)号：US20180358610A1

公开(公告)日：2018-12-13

申请号：US15779660

申请日：2016-11-29

Applicant: NEC Corporation

Inventor： Ikiko SHIMANUKI ,  Suguru TAMAI ,  Daisuke KAWASAKI ,  Hitoshi ISHIKAWA

IPC: H01M4/36 ,  H01M10/0525 ,  H01M4/38 ,  H01M4/48 ,  H01M10/0567 ,  H01M4/62 ,  H01M10/058

Abstract: 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 μm or less.