Polyolefin diaphragm for lithium battery, preparation method and electrochemical device

• Main Authors: DONG HUAN, LIU ZHIGANG, ZHANG YING, DONG QIUCHUN, LI YUEHONG, DENG PENGFEI, XUE YUNQING, LIU GAOJUN, XUE SHAN, ZHANG XUJIE, YANG HAIQUAN, JIA GUOZHONG
• Format: Patent
• Language: Chinese; English
• Published: 29.03.2024
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

The invention provides a polyolefin diaphragm for a lithium battery, a preparation method and an electrochemical device. The polyolefin diaphragm comprises high molecular weight polyethylene, high molecular weight polypropylene, a silane coupling agent and an auxiliary agent; the mass ratio of the polyethylene to the polypropylene to the silane coupling agent to the auxiliary agent is (25-30): (5-10): (1-2): (0.5-2); the difference value between the hole closing temperature and the membrane breaking temperature of the polyolefin membrane is not less than 40 DEG C. The invention also provides a preparation method of the diaphragm and an electrochemical device using the diaphragm. According to the polyolefin diaphragm for the lithium battery and the preparation method of the polyolefin diaphragm, the defects that in the prior art, the difference value between the hole closing temperature and the diaphragm breaking temperature of a polyolefin diaphragm is small, and large potential safety hazards exist are overc