Lithium-ion secondary cell and method for manufacturing same

Patent metadata

Field	Value
Publication number	US-2018076479-A1
Application number	US-201615560373-A
Country	US
Kind code	A1
Filing date	Mar 22, 2016
Priority date	Mar 24, 2015
Publication date	Mar 15, 2018
Grant date	—

Abstract

The present invention relates to a lithium ion secondary battery comprising an electrode element comprising a positive electrode, a negative electrode and a separator, and an electrolyte solution, wherein the separator has a shrinking ratio of 2% or less by heat treatment at 90 ° C. for 6 hours, and a contest of physically adsorbed water of the electrode element is 2% by mass or less, or a content of chemically adsorbed water in a positive electrode active material layer of the positive electrode is 1% by mass or less.

First claim

1 . A lithium ion secondary battery comprising an electrode element comprising a positive electrode, a negative electrode and a separator, and an electrolyte solution, wherein
the separator has a shrinking ratio of 2% or less by heat treatment at 90° C. for 6 hours, and a content of physically adsorbed water of the electrode element is 2% by mass or less.

2 . A lithium Ion secondary battery comprising an electrode element comprising a positive electrode, a negative electrode and a separator, and an electrolyte solution, wherein
the separator has a shrinking ratio of 2% or less by heat treatment at 90° C. for 6 hours, and a content of chemically adsorbed water In a positive electrode active material layer of the positive electrode is 1% by mass or less.

3 . The lithium ion secondary battery according to claim 1 , wherein the separator comprises a heat-resistant resin having a heat melting temperature or a thermal decomposition temperature of 160° C. or higher.

4 . The lithium ion secondary battery according to claim 3 , wherein the separator comprises an aramid resin.

5 . The lithium Ion secondary battery according to claim 1 , wherein the electrode element comprises one or more selected from the group consisting of:
a lithium transition metal compound produced using starting materials comprising LiON, a lithium nickel composite compound in a form of secondary particles in which primary particles are agglomerated, a positive electrode active material having a specific surface area of 1.5 m2/g or more. a negative electrode active material having a specific surface area of 4 m2/g or more, and a hydrophilic binder.

6 . The lithium ion secondary battery according to claim 1 , wherein the positive electrode comprises a lithium nickel composite compound represented by following formula (1):
Li 60 Ni 62 Me 65 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, Ti, and B.

7 . The lithium ion secondary battery according to claim 6 , comprising a lithium nickel composite compound represented by formula:
Li α Ni β Co γ Mn δ O 2 wherein 1≦α≦1.2, β+γ+δ=1, β≧0.7, and γ≦0.2, or formula:
Li α Ni β Co γ Al δ O 2
wherein 1≦α≦1.5, β+γ+δ=1, β≧0.7, and γ≦0.2,

8 . The lithium ion secondary battery according to claim 1 , wherein the electrolyte solution comprises a sulfonic acid ester compound.

9 . The lithium ion secondary battery according to claim 1 , comprising a laminate outer package.

10 . A method of manufacturing a lithium ion secondary battery comprising an electrode element comprising a positive electrode, a negative electrode and a separator, an electrolyte solution and an outer package, wherein
the separator has a shrinking ratio of 2% or less by heat treatment at 90° C. for 6 hours, and the method comprises a step of heat-drying the electrode element at 90° C. or higher before injecting the electrolyte solution.

11 . The method of manufacturing a lithium ion secondary battery according to claim 10 , wherein the step of heat-drying the electrode element is performed at 150° C. or higher.

12 . The method of manufacturing a lithium ion secondary battery according to claim 10 , wherein the separator comprises an aramid resin.

13 . The method of manufacturing a lithium ion secondary battery according to claim 10 , wherein the positive electrode comprises a lithium nickel composite oxide represented by 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, Ti, and B.

Assignees

• Nec Corp

Inventors

• Kawasaki Daisuke
• Shlmura Kenichi
• Yoshida Noboru
• Inoue Kazuhiko
• Iriyama Jiro

Classifications

• H01M4/38

  of elements or alloys · CPC title

• H01M4/02

  Electrodes composed of, or comprising, active material · 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

• H01M4/131

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

• H01M10/0525 Primary

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title