High Areal Capacity Li‐Ion Storage of Binder‐Free Metal Vanadate/Carbon Hybrid Anode by Ion‐Exchange Reaction

Abstract Storing more energy in a limited device area is very challenging but crucial for the applications of flexible and wearable electronics. Metal vanadates have been regarded as a fascinating group of materials in many areas, especially in lithium‐ion storage. However, there has not been a versatile strategy to synthesize flexible metal vanadate hybrid nanostructures as binder‐free anodes for Li‐ion batteries so far. A convenient and versatile synthesis of M_xV_yO_x+2.5y@carbon cloth (M = Mn, Co, Ni, Cu) composites is proposed here based on a two‐step hydrothermal route. As‐synthesized products demonstrate hierarchical proliferous structure, ranging from nanoparticles (0D), and nanobelts (1D) to a 3D interconnected network. The metal vanadate/carbon hybrid nanostructures exhibit excellent lithium storage capability, with a high areal specific capacity up to 5.9 mAh cm⁻² (which equals to 1676.8 mAh g⁻¹) at a current density of 200 mA g⁻¹. Moreover, the nature of good flexibility, mixed valence states, and ultrahigh mass loading density (over 3.5 mg cm⁻²) all guarantee their great potential in compact energy storage for future wearable devices and other related applications.