The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 13, 2026
Filed:
Apr. 19, 2021
Shanghai Energy New Materials Technology Co., Ltd., Shanghai, CN;
Yue Cheng, Shanghai, CN;
Kun Li, Shanghai, CN;
Kun Peng, Shanghai, CN;
Bei Jin, Shanghai, CN;
Qianqian Liu, Shanghai, CN;
SHANGHAI ENERGY NEW MATERIALS TECHNOLOGY CO., LTD., Shanghai, CN;
Abstract
The present invention relates to a separator film in a lithium battery, more specifically relates to a polyolefin microporous film and a preparation method thereof. The polyolefin microporous film has a porosity above 30% and below 65%, a median pore size above 10 nm and below 60 nm, a stress-strain (σ-ε) curve integral in Machine Direction (MD) and Transverse Direction (TD) directions simultaneously fulfilling the following definition:σ(ε)ε>150 J/m; andthe largest pore size, the smallest pore size and the median pore size fulfilling the following definition: 0.9<P<1.2, wherein P=(the largest pore size−the smallest pore size)/the median pore size. The polyolefin microporous film according to the present invention has high tenacity, small pore sizes, concentrated distribution of pore sizes, great stability for coiling, and enabling high number of battery cycles. When used as a separator film, battery manufacturing safety and the service life of the battery being made can be increased.