Two‐dimensional V2CTx In‐situ Derived Porous V2O3@C Flakes Towards Zinc‐Ion Capacitors as a Competitive Cathode Material

Abstract Zinc‐ion capacitors (ZICs) are promising electrochemical devices for energy storage due to their advantages including environmental friendliness, safety, and simple assembly. However, its application is still subject to modest rate and stable performance of the involved cathodes. In this work, we in‐situ fabricate a two‐dimensional flake‐shape framework containing amorphous carbon‐coated V 2 O 3 nanowires (V 2 O 3 @C) by using few‐layered V 2 CT x (f‐V 2 CT x ) as the raw material, and further utilize it as an appealing cathode material for ZICs. Thanks to the nanowires‐assembled porous architecture, conductive carbon coating, and rich defects through in‐situ lattice tunnel distortion of corundum‐type V 2 O 3 , the V 2 O 3 @C cathode delivers an excellent rate capability of ∼175 mAh g −1 at 8.0 A g −1 , and the stable long‐term cycling behavior (∼168.0 mAh g −1 remained after 6500 cycle at 5.0 A g −1 s). Furthermore, the V 2 O 3 @C based ZICs exhibit a specific energy density of ∼36.3 Wh kg −1 and a long‐term cycle life with a capacity retention value of 74.3% after 10,000 cycles at 1.0 A g −1 . This highlights that our V 2 O 3 @C is a competitive cathode candidate for advanced ZICs.