Vanadium dioxide (VO₂) with the advantages of high theoretical capacity and tunnel structure has attracted considerable promising candidates for aqueous zinc-ion batteries. Nevertheless, the intrinsic low electronic conductivity of VO₂ results in an unsatisfactory electrochemical performance. Herein, a flower-like VO₂/carbon nanotubes (CNTs) composite was obtained by a facile hydrothermal method. The unique flower-like morphology shortens the ion transport length and facilitates electrolyte infiltration. Meanwhile, the CNT conductive networks is in favor of fast electron transfer. A highly reversible zinc storage mechanism was revealed by ex-situ X-ray diffraction and X-ray photoelectron spectroscopy. As a result, the VO₂/CNTs cathode exhibits a high reversible capacity (410 mAh·g⁻¹), superior rate performance (305 mAh·g⁻¹ at 5 A·g⁻¹), and excellent cycling stability (a reversible capacity of 221 mAh·g⁻¹ was maintained even after 2000 cycles). This work provides a guide for the design of high-performance cathode materials for aqueous zinc metal batteries.

Lithium-sulfur (Li-S) battery is one of the promising energy storage devices because of its high energy density. However, the sulfur cathode suffers from sluggish electrochemical reaction kinetics, slow charge transfer, large volume expansion and severe shuttle effect of lithium polysulfides inevitably resulting in low reversible capacity, poor rate performance and short cycle life, limiting its practical applications. Herein, the recent progress of cobalt/carbon composites, including cobalt nanoparticles and cobalt single atoms, as the sulfur host materials in Li-S batteries is overviewed. In general, cobalt plays the role of electrocatalyst, which inhibits the shuttle effect of lithium polysulfides, accelerates the electrochemical reaction kinetics, facilitates ion/electron transfer and alleviates volume expansion. Meanwhile, the prospects for the development of cobalt/carbon composites as sulfur hosts in Li-S batteries are proposed. It is expected to offer a whole blueprint and constructive suggestions for the cobalt/carbon composites as sulfur hosts for Li-S batteries, and these strategies can also be effective for other metal-sulfur batteries.