Redox‐Active Separators for Lithium‐Ion Batteries. Issue 3 (19th December 2017)

• Record Type: Journal Article
• Authors: Wang, Zhaohui; Pan, Ruijun; Ruan, Changqing; Edström, Kristina; Strømme, Maria; Nyholm, Leif
• Is Part Of: Advanced science. Volume 5:Issue 3(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-12-19
• Subjects: capacity -- cellulose -- conducting polymers -- lithium‐ion batteries -- redox‐active separators; Science -- Periodicals; 505
• DOI: 10.1002/advs.201700663
• Languages: English
• ISSNs: 2198-3844

Abstract

Abstract: A bilayered cellulose‐based separator design is presented that can enhance the electrochemical performance of lithium‐ion batteries (LIBs) via the inclusion of a porous redox‐active layer. The proposed flexible redox‐active separator consists of a mesoporous, insulating nanocellulose fiber layer that provides the necessary insulation between the electrodes and a porous, conductive, and redox‐active polypyrrole‐nanocellulose layer. The latter layer provides mechanical support to the nanocellulose layer and adds extra capacity to the LIBs. The redox‐active separator is mechanically flexible, and no internal short circuits are observed during the operation of the LIBs, even when the redox‐active layer is in direct contact with both electrodes in a symmetric lithium–lithium cell. By replacing a conventional polyethylene separator with a redox‐active separator, the capacity of the proof‐of‐concept LIB battery containing a LiFePO4 cathode and a Li metal anode can be increased from 0.16 to 0.276 mA h due to the capacity contribution from the redox‐active separator. As the presented redox‐active separator concept can be used to increase the capacities of electrochemical energy storage systems, this approach may pave the way for new types of functional separators. Abstract : The performance of lithium‐ion batteries can be enhanced by replacing the separator with a flexible redox‐active separator comprising a cellulose layer and an electrically conducting and redox‐active layer.