Interwoven Poly(Anthraquinonyl Sulfide) Nanosheets‐Decorated Carbon Nanotubes as Core–Sheath Heteroarchitectured Cathodes for Polymer‐Based Asymmetrical Full Batteries

Abstract

Organic redox‐active polymers provide promising alternatives to metal‐containing inorganic compounds in Li‐ion batteries (LIBs), whereas suffer from low actual capacities, poor rate/power capabilities, and inferior cycling stability. Herein, poly(anthraquinonyl sulfide)‐coated carbon nanotubes (CNT@PAQS) are readily performed by in situ polymerization to form core–sheath nanostructures. Remarkably, flower‐like PAQS nanosheets are interwoven around CNTs to synergistically create robust 3D hierarchical networks with abundant cavities, internal channels, and sufficiently‐exposed surfaces/edges, thereby promoting electron transport and making more active sites accessible for electrolytes and guest ions. Apparently, the as‐fabricated CNT@PAQS cathode delivers the large reversible capacity (200.5 mAh g−1 at 0.05 A g−1), high‐rate capability (161.5 mAh g−1 at 5.0 A g−1), and impressive cycling stability (retaining 88.0% over 1000 cycles). In addition, an asymmetric full‐battery using CNT@PAQS as a cathode and cyclized polyacrylonitrile‐encapsulated CNTs as an anode is assembled that delivers a high energy density of 86.3 Wh kg−1, and retains 81.3% of initial capacity after 1000 cycles. This work opens up an efficient strategy to combine highly conductive and redox‐active phases into core–sheath heterostructures to unlock the barrier of high‐rate charge storage. The further integration of two polymer‐based electrodes into asymmetric full cells would also consolidate the development of low‐cost, sustainable, and powerful batteries.