Templated constructing honeycomb-like V5S8@C anode with multi-scale interfacial coactions and high pseudocapacitive contribution for enhanced potassium storage capability

摘要

Potassium-ion batteries (PIBs) are considered as the promising candidate for lithium-ion batteries (LIBs) nowadays, due to its abundance natural reserves and similar operation mechanisms. However, owing to the larger radius of K+ ions, the nanostructure of anode materials is easily destroyed during repeatedly intercalation/extraction process as well as fast fades of specific capacity. Therefore, constructing rational nanostructure for anode material is a significant approach to enhance the durability of PIBs. In this work, we rationally proposed a dual strategy including inducing numerous regular artificial pores in nanostructure with a honeycomb-like morphology and building multi-scale interfacial coactions between the V5S8 skeleton and exterior graphene nanosheets. Attributing to these advantages, the as-prepared V5S8@C composite exhibits an enhanced potassium storage performances, which delivers an initial charge capacity of 479.1 mAh g(-1) at 0.05 A g(-1) and a capacity of 121.5 mAh g(-1) after 500 cycles at 1 A g(-1). The further reaction kinetics results suggest the electrochemical reaction is mainly dominated by pseudocapacitive charge storage process. Our work has shed light on rational designing nanostructure for advanced electrode material in energy storage fields. (C) 2020 Elsevier B.V. All rights reserved.