Preparation And Properties Of Carbonyl Compounds/carbon Matrix Composites For Lithium/sodium Batteries

Lithium-ion batteries?LIBs?have been widely used in various portable electronic devices because of their superior performance.However,with the development of electric vehicles and energy storage market,the low lithium resources limit the future application of LIBs.In contrast,sodium-ion batteries?SIBs?have attracted widespread attention due to their inexhaustible and ubiquitous sodium resources and lower costs.However,current LIBs/SIBs rely mainly on inorganic electrode materials,which is not conducive to the development of green,environmentally friendly batteries.Therefore,this article prepared a series of carbonyl compounds/carbon composites with low environmental impact,low cost and excellent performance as electrode materials for LIBs/SIBs.The research contents and results are as follows:?1?Three-dimensional composite aerogel materials were prepared using solvothermal method by combining perylenetetracarboxylic dianhydride with graphene oxide.The composites exhibit excellent electrochemical properties,which may be due to the synergistic effect of perylenetetracarboxylic dianhydride and porous graphene.When the composites were used as cathode of LIBs,it shows an initial capacity of¹80 mAh/g and the capacity increases to²00 mAh/g after 200cycles at the current density of 50 mA/g.The composites show a capacity of⁷8mAh/g after 650 cycles at the current density of 1000 mA/g.When the materials were used as cathode for SIBs,it shows a capacity of⁹5 mAh/g at the current of 25 mA/g and retains a capcity of⁵6 mAh/g after 1000 cycles at the current of 100 mA/g.?2?The integrated flexible films were successfully prepared using vacuum filtration by combining perylenetetracarboxylic dianhydride with carbon nanotubes.The flexible film can be directly cut into flexible electrodes for LIBs/SIBs.This method not only simplifies the preparation process,but also improves the energy density and cycle performance of LIBs/SIBs.The flexible electrode used as cathode of LIBs shows an initial capacity of 66 mAh/g and the capacity increases to¹50mAh/g after 70 cycles at the current density of 50 mA/g,maintaining the high capacity of¹50 mAh/g after 500 cycles.The flexible electrode used as the cathode of SIBs shows capacities of⁵7 mAh/g at the current of 25 mA/g and⁴8 mAh/g at the current of 1000 mA/g.?3?The integrated flexible films were successfully prepared using ultrasonic-vacuum filtration by combining indigoand indigocarmine with single-walled carbon nanotubes,respectively.The flexible film can be directly cut into flexible electrodes for LIBs.By comparing the electrochemical performances of indigo/single-walled carbon nanotube and indigocarmine/single-walled carbon nanotube,the latter exhibits stable cycling performance,which is attributed to exist the-SO₃Na groups in the indigocarmine.The flexible electrode used as cathode of LIBs shows an initial capacity of⁴0 mAh/g and the capacity decreases to³4mAh/g after 1000 cycles at the current density of 50 mA/g with a capacity retention of 85%.