碳包覆KTiOPO_(4)单晶材料的结构、形貌及储钾性能  

Structure,Morphology and Potassium-ion Storage Properties of Carbon-coated KTiOPO_(4)Single Crystal

作　　者：金苏 柏玲 李子全 黄镇东 JIN Su;BAI Ling;LI Ziquan;HUANG Zhendong(State Key Laboratory for Organic Electronics and Information Displays,Nanjing University of Posts and Telecommunications,Nanjing 210023,China)

机构地区：[1]南京邮电大学材料科学与工程学院,省部共建有机电子与信息显示国家重点实验室,江苏南京210023

出　　处：《广州化学》2025年第2期45-51,I0003,共8页Guangzhou Chemistry

基　　金：国家自然科学基金面上项目(52277219)。

摘　　要：以KTiOPO_(4)为研究对象,为解决其电子电导率低、储钾性能差等关键问题,以聚乙烯吡咯烷酮(PVP)为碳源,通过球磨辅助固相烧结法制备了亚微米级碳包覆的KTiOPO_(4)单晶复合材料,以实现同时提高KTiOPO_(4)的电子电导率和电化学储钾性能目标。利用X射线衍射、扫描和透射电子显微镜、X射线光电子能谱等表征测试了所制复合材料的结构、形貌及元素组成;研究了不同碳化温度下制备的碳包覆KTiOPO_(4)复合材料在5.0 M KFSI电解液中的电化学储钾性能,结果表明,550℃下制备的单晶复合材料展现先出了最为优异的电化学性能。该材料在1 A/g的电流密度下循环500圈,放电容量保持为141.5 mAh/g,容量保持率为95.2%,库伦效率始终维持在99%以上,相较于Pure KTOP材料,循环性能提升了73.9%。This paper will take KTiOPO_(4)as the research object to solve the key problems of its poor electron conductivity and low potassium storage performance.Polyvinyl pyrrolidone(PVP)is used as a carbon source.Submicron carbon-coated KTiOPO_(4)single-crystal composites were prepared using ball-milling-assisted solid-phase sintering to improve the electron conductivity and electrochemical properties of KTiOPO_(4).The structural morphology and elemental composition of carbon-coated KTiOPO_(4)single-crystal composites are studied using X-ray diffraction,scanning and transmission electron microscopy,X-ray photoelectron spectroscopy,and other modern analytical methods.The electrochemical potassium-ion storage performance of carbon-coated KTiOPO_(4)composite material prepared at different carbonization temperatures was studied within the electrolyte of 5.0 M KFSI in DIGLYME.The results showed that the composites prepared at 550℃(KTOP-PC-550)exhibited the best electrochemical properties.After being cycled 500 times at the current density of 1 A/g,the discharge capacity of the KTOP-PC-550 electrode is still maintained at 141.5 mAh/g,the capacity retention rate is 95.2%,the Coulomb efficiency is always maintained above 99%,and the cycle performance is improved by 73.9%compared with Pure KTOP material.

关 键 词：钾离子电池 聚阴离子钛基磷酸盐 负极材料 磷酸氧钛钾 碳包覆 

分 类 号：TQ152[化学工程—电化学工业]