Affiliation:
1. Bavarian Center for Battery Technology and Macromolecular Chemistry II University of Bayreuth Universitätsstraße 30 95440 Bayreuth Germany
2. Bavarian Center for Battery Technology (BayBatt) and Chair of Electrical Energy Systems (EES) University of Bayreuth Universitätsstraße 30 95440 Bayreuth Germany
3. College of Chemistry and Chemical Engineering Jiangxi Normal University Nanchang 330022 China
4. Department of Chemistry and Bavarian Center for Battery Technology University of Bayreuth 95447 Bayreuth Germany
Abstract
AbstractLi‐Hectorite (Li‐Hec) clays have inherent 2D diffusion slits offering high lithium (Li+) ion conductivity. Such Li‐Hec clays spontaneously delaminate into flexible nanosheets, allowing them to be coated on high‐temperature stable polybenzimidazole (PBI) nanofibers laid randomly onto each other in the form of non‐woven membranes. Here such Li‐Hec coated PBI nonwovens are shown to be excellent Li‐ion battery separators. An effective strategy based on electrospinning PBI followed by a filtration‐through coating of delaminated Li‐Hec nanosheets of appropriate diameter is applied to prepare the separators without the use of any binder. The composite separator shows excellent properties, such as superior wettability (solvent uptake 413%), thermostability (>500 °C), superior flame resistance, and interfacial compatibility. Additionally, the presented separator shows excellent ion conductivity, Li‐ion transference number, cycling stability, and a rate performance that outperforms the common commercial separators. In summary, this work allows for a better balance between safety, high performance, and separator functionality.
Subject
Materials Chemistry,Polymers and Plastics,Organic Chemistry,General Chemical Engineering