Study On The Preparation And Application In Batteries Of Doped Fe-contained Coordination Compounds And Their Derivatives

Lithium-ion batteries with its high capacity,high voltage,long cycling life,environmental protection and other characteristics become one of the most development modern energies.However with the wide use of lithium-ion batteries(Libs)in the world the requirements of their performance are reaching high level.So developing new Libs anode materials is of great importance.Metal organic coordination polymers(Mocps)as a new type materials,the electrochemical properties of such a material and its derivatives have also been received a wide range of attention,becoming a good choice of the lithium-ion battery anode material.In this paper we synthesize a series of the doped iron-based Mocps and their derivatives by hydrothermal method,and research the application in the Libs.The main contents and results are listed below:(1)The Mocp with one-dimensional porous structure was successfully synthesized by hydrothermal synthesis.The structure,phase and morphologie is characterized.The composite with graphene shows a good electrochemical performance,the specific capacity can reach305mAh/g after 100 cycles at the current density of 50mA/g.An oxide was obtained via calcining the precursor in air,the first specific capacity of the oxide reached 3082mAh/ g.When it is calcined in nitrogen forming a carbon-coated oxide,the first specific capacity was of 1364mAh/g,and the specific capacity can be maintained at 230mAh/g after 100 cycles.(2)By changing the ratio of iron and zinc,a Mocp was synthesized with different structure and morphology.It is compounded with graphene,the first specific capacity was of1621mAh/g,and the specific capacity was stabilized at 200 m Ah/g after 100 cycles at a current density of 50mA/g.By pyrolysing the Mocp was decomposed into a metal oxide,the first charge-discharge capacity is higher.The specific capacity of the carbon-coated metal oxide was 260mAh/g after 100 cycles.(3)The Mocp containing iron,zinc and lithium was synthesized by hydrothermal method.The electrochemical test shows that its first specific capacity is high,up to 3636mAh/g,but the cycle stability is not good.By compounding with graphene,the specific capacity of the composites reach 158mAh/g for 100 cycles.When the Mocp as precursor is calcined,the firstspecific capacity is 1191mAh/g,the reversible specific capacity is approximately 80mAh/g after 100 cycles.(4)The Mocp containing iron and manganese was synthesized and its structure and morphology were characterized.As an electrode material,the first specific capacity is1444mAh/g,after 100 cycles the reversible capacity reached 146mAh/g.When it compounds with graphene,the specific capacity increases to 323mAh/g after 100 cycles.