Ni-hexamine Coordination Frameworks Derived Carbon-based Telluride:Preparation,Interface Design And Na-ion Storage

Sodium has similar physical and chemical properties as lithium,but it has abundant reserves and low cost.Therefore,developing a room temperature Na-ion battery is a reasonable alternative for Li-ion battery.Among the Na-ion battery electrode materials currently being studied,metal-organic framework derived carbon-based transition metal chalcogenides has shown high sodium storage capacity and reliable high rate performance.At present,most of them are focusing on three-dimensional carbon-based materials,while two-dimensional carbon matrix with rich active sites may show better performance.However,the synthesis of two-dimensional carbon-based transition metal chalcogenide based on metal organic frameworks(MOF)faces many challenges:1.Two-dimensional MOF can be prepared by interface method or stripping method.Both are suffering from complicated processes and low yield.2.The stability of most published MOFs is too low,so the two-dimension morphology usually shrinkage or collapse during the pyrolysis process.Foused on these problems,this work uses HMT as an organic ligand to synthesize two-dimension MOF.Then,carbon-based transition metal chalcogenides are prepared through carbonization and tellurization.Then,the interface design and influence of interface properties on sodium storage properties is explored.(1)Nickel telluride/nitrogen-doped carbon nanosheets(NiTe2@NCNs)are successfully prepared by two-dimensional MOF microplates as Ni-hexamine by carbonization and tellurization.As an anode material for Na-ion battery,NiTe2@NCNs exhibit excellent rate performance.The capacity are 289.5 and 271.6 mA h g-1 at 0.1 and 10 A g-1,respectively.The excellent electrochemical performance can be attributed to the high conductivity of nitrogen-doped carbon nanosheets and fast sodium ions transport in layered nickel telluride.(2)A series of heterostructure/carbon compositions are successfully prepared through bimetallic-HMT framework.The anti-blocking heterstructure is evidence to improve the electrochemical proformance.The NiTe2-ZnTe heterostructure has a reversible capacity of 256.9 and 178.48 mA h g-1 at 0.1 and 10 A g-1,respectively.After 1000 cycles at 5 A g-1,the capacity retention rate was 80.6%.Experiments and calculations prove that anti-blocking heterostructure can change the interface electron distribution and improve the ion diffusion kinetics,thereby improving the Na-ions storage performance.