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

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.