Preparation and Properties of Chitosan Based N-doped Carbon Coated FeF3 as Cathode Material for Lithium Ion Batteries
To address the challenges of easy reduction and ablation in the preparation of high-performance N-doped carbon coated FeF3 cathode materials using organic polymer materials,a preparation strategy combining H2O2 oxidation and freeze-drying was proposed.A nitrogen doped carbon coated porous FeF3 composite material was prepared at pH 1.8 using Fe(NO3)3 as the iron source and foaming agent,and chitosan as the N and C coating raw materials.The electrochemical properties of the material as a positive electrode material for lithium-ion batteries were studied.The results showed that the introduction of chitosan in the precursor solution preserved the wrapping effect of chitosan fibers in the composite material;The high-temperature O2 direct oxidation method can cause abla-tion and structural collapse of chitosan porous fibers.During the fluorination process after carbonization,a hydro-thermal synthesis method combining H2O2 oxidation and NH4HF2+NaH2PO4 fluorination is used to maintain the high valence state of Fe element in N-doped carbon coated FeF3 composite material,thereby enabling it to have an initial capacity of 208 mAh/g and good cycling performance in the charge discharge range of 4.5～2.0 V.This meth-od can effectively utilize the advantages of natural polymer fibers such as chitosan to prepare highly active porous FeF3 cathode materials.The strategy proposed in this study is simple and effective,and has guiding significance for the preparation of various N-doped carbon coated composite materials.
lithium ion batterycathodechitosaniron fluorideN-doped carbon coating material
万方数据
