InSitu-Formed Hierarchical Metal-Organic Flexible Cathode for High-Energy Sodium-Ion Batteries

Metal-organic compounds are a family of electrode materials with structural diversity and excellent thermal stability for rechargeable batteries. Here, we fabricated a hierarchical nanocomposite with metal-organic cuprous tetracyanoquinodimethane (CuTCNQ) in a 3D conductive carbon nanofibers (CNFs) network by insitu growth, and evaluated it as flexible cathode for sodium-ion batteries (SIBs). CuTCNQ in such flexible composite electrode is able to exhibit a high capacity of 252mAhg(-1) at 0.1C and highly reversible stability for 1200cycles within the voltage range of 2.5-4.1V (vs. Na+/Na). A high specific energy of 762Whkg(-1) was obtained with high average potential of 3.2V (vs. Na+/Na). The insitu-formed electroactive metal-organic composites with tailored nanoarchitecture provide a promising alternative choice for high-performance cathode materials in SIBs with high energy.