Designing N-doped graphene/ReSe2/Ti3C2 MXene heterostructure frameworks as promising anodes for high-rate potassium-ion batteries

Abstract

A N -doped graphene/ReSe 2 /MXene heterostructure is enabled by all-CVD route, readily demonstrating high-rate K-ion storage performance as hybrid anode candidate. Developing high-performance anodes for potassium ion batteries (KIBs) is of paramount significance but remains challenging. In the normal sense, electrode materials are prepared by ubiquitous wet chemical routes, which otherwise might not be versatile enough to create desired heterostructures and/or form clean interfacial areas for fast transport of K-ions and electrons. Along this line, rate capability/cycling stability of resulting KIBs are greatly handicapped. Herein we present an all-chemical vapor deposition approach to harness the direct synthesis of nitrogen-doped graphene (NG)/rhenium diselenide (ReSe 2 ) hybrids over three-dimensional MXene supports as superior heterostructure anode material for KIBs. In such an innovative design, 1T′-ReSe 2 nanoparticles are sandwiched in between the NG coatings and MXene frameworks via strong interfacial interactions, thereby affording facile K + diffusion, enhancing overall conductivity, boosting high-power performance and reinforcing structural stability of electrodes. Thus-constructed anode delivers an excellent rate performance of 138 mAh g −1 at 10.0 A g −1 and a high reversible capacity of 90 mAh g −1 at 5 A g −1 after 300 cycles. Furthermore, the potassium storage mechanism has been systematically probed by advanced in situ / ex situ characterization techniques in combination with first principles computations.