Lithium ion secondary cell

Patent metadata

Field	Value
Publication number	US-2016233485-A1
Application number	US-201415022245-A
Country	US
Kind code	A1
Filing date	May 23, 2014
Priority date	Sep 17, 2013
Publication date	Aug 11, 2016
Grant date	—

Abstract

A lithium ion secondary cell comprises a negative electrode mixture layer containing 5 to 45% by mass of at least one negative electrode active material selected from the group consisting of hard carbon, soft carbon, Sn, Sn alloys, Si, Si alloys, SiOx (0<x<2), Ge, Ge alloys, carbon nanotubes, and carbon nanofibers, and a positive electrode mixture layer containing a lithium-containing transition metal oxide. The negative electrode mixture layer satisfies (Initial charge capacity per unit mass of the negative electrode mixture layer)/(Initial discharge capacity per unit mass of the negative electrode mixture layer)≧1.3.

First claim

1 . A lithium ion secondary cell comprising:
a negative electrode mixture layer containing 5 to 45% by mass of at least one negative electrode active material selected from the group consisting of hard carbon, soft carbon, Sn, Sn alloys, Si, Si alloys, SiO x (0<x<2), Ge, Ge alloys, carbon nanotubes, and carbon nanofibers; and a positive electrode mixture layer containing a lithium-containing transition metal oxide, wherein the negative electrode mixture layer satisfies the following formula:
(Initial charge capacity per unit mass of the negative electrode mixture layer)/(Initial discharge capacity per unit mass of the negative electrode mixture layer)≧1.3

2 . The lithium ion secondary cell according to claim 1 , wherein the negative electrode mixture layer further contains 105 to 500 parts by mass of graphite based on 100 parts by weight of the negative electrode active material.

3 . The lithium ion secondary cell according to claim 1 , wherein the negative electrode active material is SiO x (0<x<2).

4 . The lithium ion secondary cell according to claim 2 , wherein the negative electrode active material is SiO x (0<x<2).

Assignees

• Toyota Jidoshokki Kk

Inventors

• Watanabe Nagisa
• Niwa Junichi

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M4/621

  Binders · CPC title

• H01M4/625

  Carbon or graphite · CPC title

• H01M4/131

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title