A Rational Design for a High‐Safety Lithium‐Ion Battery Assembled with a Heatproof–Fireproof Bifunctional Separator. (11th December 2020)

• Record Type: Journal Article
• Authors: Peng, Longqing; Kong, Xiangbang; Li, Hang; Wang, Xin; Shi, Chuan; Hu, Texiong; Liu, Yizhen; Zhang, Peng; Zhao, Jinbao
• Is Part Of: Advanced functional materials. Volume 31:Number 10(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-12-11
• Subjects: ceramic‐coated separator -- high energy density -- high safety -- inflaming retarding -- lithium‐ion battery; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202008537
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: High‐Ni‐content LiNi x Co y Mn1− x − y O2 is regarded as a feasible cathode material to meet the urgent requirement for high energy density batteries. However, such cathode has a poor safety performance because of reactive oxygen releasing at elevated temperatures. In pursuit of high‐safety lithium‐ion batteries, a heatproof–fireproof bifunctional separator is designed in this study by coating ammonium polyphosphate (APP) particles on a ceramic‐coated separator modified with phenol‐formaldehyde resin (CCS@PFR). The CCS@PFR separator acts as a thermal‐supporting layer to inhibit the shrinkage of the separator at elevated temperatures, whereas the APP‐coated layer functions as a fireproof layer, forming a dense polyphosphoric acid (PPA) layer above 300 °C. The PPA layer not only isolates the combustibles from the highly reactive oxygen released from the cathodes but also converts violent combustion reactions into mild stepwise exothermic reactions by carbonizing the combustibles in the batteries. Enabled with such a heatproof–fireproof bifunctional separator, LiNi0.8 Co0.1 Mn0.1 O2 |SiO x −Gr full cells are constructed and these exhibit an excellent safety performance by not catching fire during a 30 s combustion test and surviving the 10 min high‐temperature test above 300 °C. Additionally, an adiabatic rate calorimeter and nail penetration test are conducted with 3 Ah LiNi0.8 Co0.1 Mn0.1 O2 |SiO x −Gr pouch cells to further verify the safety performance. Abstract : A high‐safety lithium‐ion battery assembled with a heatproof–fireproof bifunctional separator is developed. The heatproof layer acts as thermal‐supporting layer to inhibit internal short‐circuit, and the fireproof layer will from a dense layer at elevated temperatures to prevent the burning of the battery. Consequently, the thus‐constructed cell exhibits excellent safety performance by surviving a series of safety tests.