Study On The Preparation And Electrochemical Performance Of Sycamore-based Carbon Electrode Material

Biomass often refers to animal or plant-based materials derived from nature,as one of the most abundant renewable resources on earth,the richness of the carbon element and welloriented channels for the metabolic process make these biomass-based electrode materials suitable for rapid ion transportation during electrochemical charge-discharge applications,which is very suitable as an energy storage material.Meanwhile,due to its widespread availability,renewable nature,and low cost,when applied to energy storage materials,it can greatly reduce its industrialization cost of SIB.Various factors have made it the electrode material of first choice for lithium/sodium ion batteries and supercapacitors.The biomass sycamore fruit is mainly composed of sycamore seed,sycamore fiber and sycamore kernel.This paper first selects the sycamore seed tissue as a precursor and carbonizes at different temperatures to obtain SFS-x hard carbon,in order to explore the effect of different carbonization temperatures on the structure and electrochemical performance of SFS-x.The results show that the SFS-1100 electrode has a reversible specific capacity of 323 m Ah g^-1at a current density of 0.1 C,and a capacity retention rate of 88.15%after 300 cycles at 0.4 C,showing excellent sodium storage performance and long cycle stability.This would be caused the rich defect structure and large interlayer distance(d₀₀₂?0.37 nm)of SFS-x,which can promote the rapid storage and release of Na⁺between graphite layers,so it exhibits higher sodium storage capacity and better Long cycle stability.The sycamore fiber tissue was continued to be used as the precursor,and SFF-x hard carbon was prepared by the same carbonization process and tested for sodium storage performance.The two types of tissues were compared for their original morphology and physical and chemical properties after carbonization.The results show that the SFF-1300 electrode has a high reversible specific capacity of 396.1m Ah g^-1at 0.1 C,and the SFF-1100 electrode owns capacity retention of 77.85%after300 cycles at 0.4 C.By comparing the two kinds of hard carbon,it can be found that,unlike the SFS-x sample,in addition to the 1.5 nm micropores,the SFF-x sample owns certain proportion of mesopores and macropores,which is more conducive to the rapid transmission of Na⁺,so that it exhibits higher reversible specific capacity and better capacity retention ability at 0.1 C-1 C.At the same time,both types of hard carbon have large interlayer distance(d₀₀₂?0.37 nm),which is conducive to the rapid storage and release of Na⁺between graphite layers,therefore both exhibit excellent long cycle stability.KOH was used as an activator to chemically activate sycamore fiber precursors.The effects of different alkali-carbon ratios on the structure and electrochemical performance of sycamore fiber-based porous carbon were studied.The results show that as the alkali-to-carbon ratio increases,the specific surface area of the sample first increases and then decreases.When the alkali-to-carbon ratio is 3:1?SFFAC-3?,the sample has the largest specific surface area of 2432.1 m²g^-1and displays high specific capacitance of 114.7 F g^-1,and owns a capacity retention rate of 89.2%after 1000cycles at the current density of 500 m A g^-1,showing excellent cycle stability.This is due to the large specific surface area and good electrical conductivity of the SFFAC-3sample,this is due to the large specific surface area and good electrical conductivity of the SFFAC-3 sample,which results in a high specific surface area and good long-cycle stability.