Achieving stability and flexibility of vanadium dioxide cathode-based zinc ion batteries with MXene binder and carbon nanotube structural reinforcer

Vanadium-based compounds are increasingly recognized to be promising for constructing safe and stable Zinc ion batteries (ZIBs). However, it is still a challenge to balance the mechanical flexibility and electrochemical performance for achieving flexible ZIBs (FZIBs). Herein, MXene and single-walled carbon nanotube(SWCNT)colloids are used respectively as conductive binders and structural reinforcements to achieve the desired flexibility and electrochemical properties. Systematic structural, morphological, and electrochemical evaluations show that the prepared freestanding cathode delivers decent rate capabilities, specific capacities (325.3 mAh g−1 at 0.1 A g−1), and cycling stability (2000 cycles without obvious decay). Additionally, the cathode, benefitting from its interwoven frame network, demonstrates rapid electrochemical reaction kinetics. The quasi-reversibility of zinc ion storage in the electrode is further confirmed through a series of ex-situ characterization methods, providing evidence for its cycling stability. Most Importantly, as a result of the mechanical flexibility of the electrode, the fabricated FZIBs display a robust electrochemical stability in both a natural planar and bending states. Therefore, the strategy presented in this work is an effective approach for fabricating vanadium dioxide based FZIBs suitable for flexible electronics for many applications such as daily healthcare monitoring.