Lithium ion secondary battery

Patent metadata

Field	Value
Publication number	US-2018013169-A1
Application number	US-201515534241-A
Country	US
Kind code	A1
Filing date	Dec 8, 2015
Priority date	Dec 11, 2014
Publication date	Jan 11, 2018
Grant date	—

Abstract

A secondary battery in which heat resistance is excellent and the formation of lithium dendrite is suppressed is provided. The present invention relates to a secondary battery comprising an electrode element comprising a positive electrode, a negative electrode and a separator, wherein the negative electrode comprises a carbon material (a) capable of absorbing and desorbing lithium ions and an oxide (b) capable of absorbing and desorbing lithium ions, and the separator comprises 50% by mass or more of a non-woven fabric having a thermal melting or thermal decomposition temperature of 160° C. or more.

First claim

1 . A secondary battery comprising an electrode element comprising a positive electrode, a negative electrode and a separator, wherein
the negative electrode comprises a carbon material (a) capable of absorbing and desorbing lithium ions and an oxide (b) capable of absorbing and desorbing lithium ions, and the separator comprises 50% by mass or more of a non-woven fabric having a thermal melting or thermal decomposition temperature of 160° C. or more.

2 . The secondary battery according to claim 1 , wherein the separator has a thickness of 10 μm or more and 25 μm or less.

3 . The secondary battery according to claim 1 , wherein the non-woven fabric comprises an aramid fiber assembly.

4 . The secondary battery according to claim 1 , wherein the content of the carbon material (a) capable of absorbing and desorbing lithium ions in a negative electrode active material is 70% by mass or more.

5 . The secondary battery according to claim 1 , wherein the negative electrode further comprises a metal material (c) capable of forming an alloy with lithium.

6 . The secondary battery according to claim 1 , wherein the metal constituting the oxide (b) capable of absorbing and desorbing lithium ions and the metal material (c) capable of forming an alloy with lithium are the same elements.

7 . The secondary battery according to claim 1 , wherein the carbon material (a) capable of absorbing and desorbing lithium ions comprises graphite.

8 . The secondary battery according to claim 1 , wherein the oxide (b) capable of absorbing and desorbing lithium ions comprises a silicon oxide.

9 . The secondary battery according to claim 1 , wherein the positive electrode comprises the positive electrode active material comprising a lithium nickel composite oxide represented by the following formula (1):
Li α Ni β Me γ O 2   (1)
(wherein 0.9≦α≦1.5, β+γ=1, 0.6≦β<1, Me is at least one selected from the group consisting of Co, Mn, Al, Fe, Mg, Ba and B.)

10 . An assembled battery comprising a plurality of the secondary batteries according to claim 1 .

11 . A vehicle equipped with the secondary battery according to claim 1 .

12 . (canceled)

13 . (canceled)

Assignees

• Nec Corp

Inventors

• Kawasaki Daisuke
• Shimura Kenichi
• Ishikawa Hitoshi

Classifications

• H01M50/443

  Particulate material · CPC title

• H01M50/417

  Polyolefins · CPC title

• H01M50/491

  Porosity · CPC title

• H01M50/489

  Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties · CPC title

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title