Preparation Of Composites Containing Black Phosphorus And Study On Supercapacitor Performance

As a new type of energy storage device,supercapacitor has the advantages that the mainstream lithium ion battery does not have,such as fast energy storage,high power density,super long cycle life,high safety and easy realization of miniaturized devices.Compared with lithium ion batteries,micro supercapacitors also have these advantages and are widely used in some small and micro devices.As a key factor,electrode material directly determines the performance of supercapacitors.As the cathode material of lithium ion battery,elemental phosphorus has a high theoretical specific capacity(2596m Ah g^-1),which indicates its excellent energy storage performance.As a new two-dimensional material,black phosphorus(BP)has been widely applied in various energy storage fields since its discovery.In order to explore the impact of BP on the performance of supercapacitors,this paper uses BP as the basis to prepare composite materials made of BP and other materials,and prepares them into new electrode materials.The properties of supercapacitors are explored and put into practical application.In this paper,firstly,in order to explore the improvement of the performance of supercapacitor electrode materials by BP,flake manganese dioxide(Mn O₂)was grown on monolayer graphene(GR)through chemical synthesis to form the GR/Mn O₂composite.In addition,a small amount of BP was added to the N-methyl pyrrolidone(NMP)dispersion of BP in the mixing process to form the GR/Mn O₂/BP composite slurry.The performance of the working electrode prepared by two different slurry materials was tested.The results showed that the specific capacitance value of the electrode was greatly increased after the addition of BP,reaching 240 F g^-1,and the multiplier was also greatly increased,reaching 80%.This indicates that the combination of BP is beneficial to the improvement of supercapacitor performance.This is not only due to the specific capacitance of BP itself,but also its synergistic effect with the composite materials of GR and Mn O₂,which makes the layered stacked structure of the electrode material beneficial to the desorption and adsorption of ions during the charge and discharge process.Then,the preparation and practical application of miniature supercapacitors are studied.Using GR/Mn O₂/BP composite material with excellent performance,the concentric circle miniature supercapacitor was prepared by screen printing technology,and the fabricated miniature supercapacitor was combined with the flexible thin film pressure sensor to realize the integration of the in-plane system.Finally,Sb-Sb₂O₅@P composite material and Sb-Sb₂O₅@P@C composite material with carbon coating structure were prepared in batches by simple high energy mechanical grinding(HEMM).After characterization of the material,it was found that under the condition of two-step high-energy mechanical grinding,the phase transition of red phosphorus occurred,and part of it was transformed into black phosphorus.Two kinds of materials were used respectively to prepare working electrodes using carbon paper as the collector system.Through electrochemical performance test and analysis of the electrodes,it was found that the specific capacitance of the composite material after the phase transition of red phosphorus could reach 109.7 F g^-1 under the condition of carbon coating.This can be attributed to the phase deformation of red phosphorus into a red-black phosphorus composite with excellent interface.This interface property improves the performance of the electrode,and the wrapping of carbon material can improve the specific capacitance and cycle performance of the electrode to a certain extent.