Title:
POLYOLEFIN MICROPOROUS MEMBRANE
Document Type and Number:
WIPO Patent Application WO/2018/164055
Kind Code:
A1
Abstract:
The purpose of the present invention is to provide a polyolefin microporous membrane with excellent self-discharge characteristics and rate characteristics when built into a secondary battery as a separator. The product of the K value (mV/hr) calculated with the expression below and the film thickness (μm) is less than or equal to 0.40 mV*μm/hr, and the air permeability is less than or equal to 200 s/100 cm3. Expression: K value (mV/hr) = [V1(mV)-V2(mV)]/24(hr) (In this expression, V1 and V2 are the open circuit voltage (V1) after leaving the secondary battery for 24 hours, and the open circuit voltage (V2) after leaving the secondary battery for 48 hours, after charging the secondary battery with constant voltage at room temperature at 0.5 C until 3.85 V, and subsequently charging with a constant voltage at 3.85 V until 0.05 C. The aforementioned secondary battery is provided with a positive electrode containing a lithium cobalt composite oxide as the positive electrode active substance, a negative electrode containing artificial graphite as the negative electrode active substance, a separator formed from the aforementioned polyolefin microporous film, and a nonaqueous electrolyte.)
Inventors:
NISHIMURA NAOYA (JP)
KANEDA TOSHIHIKO (JP)
CHEN YANZI (JP)
KANEDA TOSHIHIKO (JP)
CHEN YANZI (JP)
Application Number:
PCT/JP2018/008333
Publication Date:
September 13, 2018
Filing Date:
March 05, 2018
Export Citation:
Assignee:
TORAY INDUSTRIES (JP)
International Classes:
C08J9/00; C08J9/26; H01M50/443; H01M50/491
Foreign References:
| JP2016085980A | 2016-05-19 | |||
| JP2015208893A | 2015-11-24 | |||
| JP2011184671A | 2011-09-22 | |||
| JP2012052085A | 2012-03-15 | |||
| JP2005209452A | 2005-08-04 | |||
| JP2014162851A | 2014-09-08 |
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