Microspherical Copper Tetrathiovanadate with Stable Binding Site as Ultra-Rate and Extended Longevity Anode for Sodium-Ion Half/Full Batteries

Vanadium sulfides are appeared and investigated for the application of sodium-ion batteries (SIBs) due to their adjustable structure and high theoretical capacity. Nevertheless, their inferior sodiation/desodiation kinetics during cycling and convoluted Na + storage mechanism severely restricts their application in SIBs. Herein, a facile one-step hydrothermal approach is applied to synthesize interconnected and homogeneous Cu 3 VS 4 microspheres with enhanced intrinsic conductivity. With the benefits of improving the electrochemical kinetics and modulation the stress relief. As applied in SIBs, the Cu 3 VS 4 deliver a high capacity of 500 mAh g -1 after 100 cycles at 0.2 A g -1 . Impressively, an ultra-stable capacity of 274 mAh g -1 after 25000 cycles of Cu 3 VS 4 can be achieved at 20 A g -1 . The first-principles calculations are detailed given to confirm the sodium storage mechanism and extended longevity of the Cu 3 VS 4 . A Na 3 V 2 (PO 4 ) 2 O 2 F cathode is construct to assemble the full cell, also exhibiting a magnificent energy density of 171 Wh kg -1 and remarkable cycling stability (5000 cycles). We first time show the comprehensive understanding of superior SIBs performance of Cu 3 VS 4 from both experimental and theoretical perspectives, giving the possibility for the next-generation advanced energy storage device