The Preparation of High Content Phosphorus/Sulfur Co-Doped Carbon Network and Its Application in Potassium Ion Battery
To address the issue of low phosphorus content in doped carbon materials,red phosphorus was utilized as both a template and a phosphorus source.Through a one-step synthesis using plasma-enhanced chemical vapor deposition,a high-content phosphorus/sulfur co-doped carbon network(PSCN)was synthesized and applied to potassium-ion batteries.Experimental results indicated that the carbon/phosphorus/sulfur mixed plasma co-deposition process enabled the preparation of a carbon material with a high content of phosphorus/sulfur doping(31.11 wt%).The obtained material exhibited a bowl-shaped carbon network structure.Due to the co-doping of phosphorus and sulfur,PSCN demonstrated characteristics such as large carbon spacing,high defect levels,large specific surface area,abundant micropores,and good thermal stability.When PSCN was utilized as the anode material for potassium-ion batteries,at a current density of 100 mA∙g-1,the reversible capacity reached 557.1 mAh∙g-1.Even at a current density of 5 A∙g-1,the reversible discharge capacity was 140.3 mAh∙g-1,and after 1 000 cycles,the capacity remained at 137.4 mAh∙g-1,representing a capacity retention rate of 69.5%.This exhibited excellent rate and cycling performance.In contrast,the reversible capacity of phosphorus-doped carbon material(PC)at a current density of 100 mA∙g-1 was 457.3 mAh∙g-1,and after 1 000 cycles at 5 A∙g-1,the capacity was only 62.8 mAh∙g-1 with a poor capacity retention rate(43.4%).The bowl-shaped structure of this material facilitated electrolyte infiltration,while the fine fibers within the carbon network significantly suppressed the volume expansion caused by the K+insertion/deinsertion process,thereby effectively enhancing the rate and cycling performance of potassium-ion batteries.Additionally,the high content of phosphorus/sulfur co-doping increased the active sites of the carbon material,promoting potassium storage kinetics and ion transport capabilities,thereby effectively enhancing rate performance,pseudo-capacitance ratio,and K+diffusion coefficient,reducing reaction resistance.The high-content phosphorus/sulfur co-doped carbon network can provide a reference for the development of preparation processes for anode materials for potassium-ion batteries,offering theoretical support.
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