| 초록 |
A substrate-free flexible carbon-coated FeS2 fibers-based cathodes for rechargeable sodium ion batteries (NIBs) is reported for the first time. A facile electrospinning technique followed by carbonization was employed for the synthesis of a novel cathode for a NIB. A discharge capacity of about 808.26 mAh/g was obtained in the first charge-discharge cycle, which is greater than that of any previously reported Na/FeS2-based battery. The carbon coating on the FeS2 fiber allows the battery to have an enhanced discharge capacity of 633.43 mAh/g, even after undergoing five charge-discharge cycles at a 0.1C rate. At a 2C rate, a lofty specific capacity of 393.53 mAh/g is maintained, and the value increases on the return from 2C to 0.1C until it reaches a value similar to the initial 0.1C rate. A superior rate capability with enhanced electrochemical stability of the NIB is also demonstrated due to the substrate-free flexible carbon-coated FeS2 fibers-based cathode. The unique structure of the carbon coated fibrous FeS2 electrode not only prevents dissolution of the polysulfide, but also improves the electrochemical reaction by increasing the migration rate of electrons and ions. |
