| Supercapacitor is a new type of energy storage equipment,which has the characteristics of fast charge and discharge rate,high power density and long cycle life.Researchers have been focusing on the synthesis and optimization of high-performance electrode materials.Carbon ma-terials,metal oxides,and conductive polymers are three common supercapacitor electrode mate-rials.In this paper,multiple transition metal oxides are taken as the research object,and their mi-crostructure and electrochemical properties are explored.The main research contents are as fol-lows:A simple,convenient and fast hydrothermal method and sintering process were used to pre-pare a Co3O4 electrode with a three-level structure of filament nano particles capable of ultra-fast charge and discharge.The prepared Co3O4 electrode has a rate performance of 95.6%at 80 times the current density of 0.5 A g-1 to 40 A g-1.After 2000 charge and discharge cycles with a current density of 2 A g-1,Its cyclic stability reaches 98.5%.At the same time,the asymmetric supercapacitor with a three-stage structure of Co3O4 exhibits an energy density of 16.25 Wh kg-1 when the power density is 7500 W kg-1.The hydrothermal synthesis method was used to explore the effect of different alkaline agents on the morphology and structure of the NiCo2O4 electrode material by controlling the ad-dition of different alkaline agents.With the simultaneous addition of urea and ammonium fluo-ride,the synthesis was successful.The "sea urchin-like" NiCo2O4 electrode material can achieve a specific capacity of 865 F g-1 at a current density of 0.5 A g-1.Both of them added the synthe-sized NiCo2O4 electrode material at the same time,the current density increased by 20 times,the capacitance retention rate reached 96.7%,and 1000 charge and discharge cycles were carried out at a current intensity of 10A g-1,and the capacitance retention rate reached 94.7%.Using the template method,carbon spheres synthesized from different carbon sources were used as templates to obtain a hollow core-shell structure NiCo2O4.This special structure can provide low-resistance paths and short paths for electrolyte ions entering the material,which greatly promotes the Faraday reaction in the internal structure,provides effective channels for the diffusion of electrolyte ions,and greatly increases the active material.Specific surface area.The prepared electrode material showed a high specific capacitance of 706.61 F g-1 at a current density of 0.5 A g-1 in an electrolyte of 1M KOH.When the current density was increased to 20 times,the specific capacitance was 515.19 F g-1,the magnification remained at 72.91%.After 1000 charge and discharge cycles at a current density of 10 A g-1,the specific capacitance reten-tion rate was 87.25%.The cycle stability of NiCo2O4 electrode materials synthesized from car-bon sphere templates prepared with glucose and sucrose as carbon sources can reach 101.11%and 100.56%.Using in-situ growth method,NiCo2O4 is directly grown on the surface of the current col-lector,and the calcination experiment is performed at different calcination temperatures,which not only simplifies the electrode manufacturing process,but also the nickel foam matrix acts as an effective carrier and increases conductivity It provides low-resistance paths and short paths for electrolyte ions entering the material.At the same time,the micronized size greatly shortens the path for electrolyte ions to enter the microstructure,which greatly promotes the Faraday re-action in the internal structure.When the calcination temperature is 300 ?,the sample exhibits excellent electrochemical performance.If the current density of 0.5 A g-1,it exhibits a high spe-cific capacitance of 1800 F g-1.When the current density increases to 10 A g-1,the specific ca-pacitance is still as high as 1320 F g-1.Although the capacitance retention rate is 72%,its specific capacitance at high current density still has excellent performance. |
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