High-loading NaCrO2 @C nanofibers as binder-free cathode for high-stable sodium-ion batteries

A NaCrO 2 @C flexible free-standing cathode is designed and fabricated via a facile electrospinning strategy, in which electrochemically active NaCrO 2 nanoparticles homogeneously dispersed in the flexible carbon nanofibers . Serving as the binder-free cathode for sodium-ion batteries, the as-constructed NaCrO 2 @C flexible free-standing cathode delivers a long cycling life (81 % capacity retention after 1000 cycles) with a high loading (7.6 mg cm −2 ). The enhancements for sodium-ion insertion/desertion is assigned to the dramatically decrease the polarization between electrodes and avoid the volume expansion during high-rate cycling. The NaCrO 2 @C flexible free-standing cathode opens up exciting possibilities for the development of advanced flexible sodium-ion batteries with both excellent mechanical flexibility and electrochemical properties .