Nonsolvent-induced electrospun fibers with crater-like surface and high-loading polytriphenylamine-derived as a flexible cathode for lithium-ion batteries

Abstract

Fabricating electrodes simultaneously possessing remarkable flexibility, excellent mechanical properties, and high energy density remains a significant challenge in flexible lithium-ion batteries (LIBs). Herein, a series of flexible organic composite films were prepared with high-loading polytriphenylamine (PTPA) and the derivative (PTPA-PO) as active material, along with carbon nanotubes (CNTs) serving as conductive filler. The fabrication employed the polyethylene oxide (PEO) assisted nonsolvent (or poor solvent) induced phase separation electrospinning (NIPSE) method. Subsequently, the fiber morphology and electrochemical applications of the flexible organic composite films were systematically studied. Notably, the 60 % PTPA-PO/20 % CNTs/PEO flexible electrode with a high-loading active material of 60 wt% exhibits a significant discharge capacity of 146.6 mAh·g−1 and a favorable discharge platform ∼ 3.7 V vs. Li. Furthermore, the inherent flexibility of electrode contributes to efficient and stable transport of ions and electrons, resulting in a fine capacity retention of 93.3 % after 100 cycles. The improvement of electrochemical performance can be rationalized by the unique internal conductive network and crater-like surface structure of the fibers formed through the NIPSE method. This work provides an efficient method to fundamentally improve the energy storage performance and flexibility of LIBs.