One-Step Construction of V5S8 Nanoparticles Embedded in Amorphous Carbon Nanorods for High-Capacity and Long-Life Potassium Ion Half/Full Batteries

Potassium ion batteries (KIBs) have attracted great attention recently as a promising large-scale energy storage system by virtue of the bountiful K resource and low standard hydrogen potential of K+/K. However, their development is hindered by the limited capacity and inferior cycling stability resulting from the large size of K+. Here, a unique vanadium sulfide@carbon nanorod is designed and synthesized for high-performance KIBs. Thanks to the hybrid structure, abundant active sites, fast ion diffusion, and capacitive-like electrochemical behavior of the electrode, the anode exhibits a large specific capacity (468 mA h g(-1) after 100 cycles at 0.1 A g(-1)), predominant rate performance (205 mA h g(-1) at 5 A g(-1)), and impressive cycling stability (171 mA h g(-1) for 4000 cycles at 3 A g(-1)). Furthermore, the constructed KIB full cell demonstrates 229 mA h g(-1) at 0.5 A g(-1) and 86% capacity retention over 300 cycles.

Automated summary

A unique vanadium sulfide@carbon nanorod has been designed and synthesized for high-performance potassium ion batteries, exhibiting large specific capacity, predominant rate performance, and impressive cycling stability. The constructed potassium ion battery full cell demonstrates good capacity retention over 300 cycles.