Application Of Chalcogenide Heterostructure In Cathode Material Of Aluminum-Ion Battery

The development of safe,stable,efficient and environment-friendly energy storage equipment is the core goal of alleviating the energy and environmental crisis.Meanwhile,the demand for mobile applications and large-scale energy storage continues to grow rapidly.Therefore,the development of clean and efficient energy conversion and storage technologies has become an imperative.Rechargeable battery,as an efficient energy storage device,has been attracting growing attention.Among rechargeable battery,aluminum-ion battery(AIB)is considered to possess significant potential as the next generation of secondary batteries due to its abundant reserves,high theoretical specific capacity and high safety.And the development of AIB is essential to meet the future energy storage demands of modern society.However,the development of AIB has been hampered by limitations in the availability of suitable cathode materials,hence the development of reliable cathode materials is a key challenge for emerging AIB.This article focuses on the research of chalcogenide heterostructure in cathode material of AIB.Based on electrostatic self-assembly technology and hydrothermal,we have synthesized NiCo2Se4/NiCoS4 and NiSe2/CoSe2@rGO,both of which exhibit excellent electrochemical performance as cathode materials for AIB.1.The heterostructured NiCo2Se4/NiCoS4 composite was synthesized by twostep hydrothermal method,in which the NiCoS4 nanoparticles were uniformly distributed on the NiCo2Se4 nanosheets.The electrochemical performance and chargedischarge mechanism of NiCo2Se4/NiCoS4 as cathode materials for AIB were investigated.At a current density of 1 A g-1,the NiCo2Se4/NiCoS4 cathode can maintain a discharge specific capacity of 112 mA h g-1 after 195 cycles with a coulomb efficiency of 94%.X-ray photoelectron spectroscopy(XPS)demonstrated that the operational mechanism of the AIB is the intercalation of Al3+ and the redox reaction of Co,Ni,and S elements.2.The heterostructured NiSe2/CoSe2 hollow microsphere was prepared by onestep hydrothermal method,then NiSe2/CoSe2 microspheres were loaded on graphene sheets by electrostatic self-assembly technology,and NiSe2/CoSe2@rGO composites eventually were synthesized.The NiSe2/CoSe2 heterostructure can enhance the conductivity and electrochemical kinetics of the electrode,and the introduction of graphene enhances the structural stability of the host material.Hence the NiSe2/CoSe2@rGO composite shows excellent electrochemical performance with the blessing of the double modification strategy.At a current density of 1 A g-1,the reversible specific capacity of NiSe2/CoSe2@rGO electrode after 100 cycles is 104 mA h g-1,and still maintained in 94 mA h g-1 after 170 cycles.It was confirmed that Al3+ as a guest ion was reversible intercalation/deintercalation in the NiSe2/CoSe2@rGO cathode.