Customizable crystalline-amorphous rectifying heterostructure cathodes for durable and super-fast zinc storage

Abstract

The development of high-capacity, quick-charging, long-lasting cathodes is crucial for the advancement of aqueous zinc ion batteries (AZIBs). However, it is still challenging to develop electrodes with all these interconnected properties. Using a customized high-crystalline material prepared by employing the physical vapor transport method, this study reports the design of a unique VSSe–V₂O₅ core–shell composite with crystalline–amorphous characteristics, facilitated via the electrochemical oxidation of VSSe to form an amorphous heterogeneous surface. The superior conductivity of the metallic VSSe core directly facilitates rapid electron transfer. Meanwhile, the amorphous V₂O₅ shell presents prominent hydrophilic and zincophilic traits that bolster the spontaneous adsorption of zinc ions. At the heterogeneous interface, the interaction between VSSe and V₂O₅ generates a unique built-in electric field, enhancing outward rectification from the core. Owing to such a crystalline–amorphous core–shell heterogeneous structure, this electrode displays superior rate performance with a discharge capacity of 162 mA h g⁻¹ at an ultrahigh current density of 50 A g⁻¹. Furthermore, it delivers a specific capacity of 176 mA h g⁻¹ at 30 A g⁻¹ with a remarkable 17 000-cycle lifespan and a capacity retention of 93%. In addition, this customized design can be extended to other materials, such as VS_0.5Se_1.5, VS_1.5Se_0.5, and MnS_0.5Se_0.5. This work underscores the impressive storage performance of the crystalline–amorphous rectifying heterogeneous cathodes and highlights the surface amorphous heterogenization of customized materials as a promising direction for developing robust cathodes and advanced aqueous zinc-ion batteries.