The development of a high-performing pseudocapacitor requires a comprehensive understanding of electrode materials from the aspects of electron transfer and electrolyte ion adsorption and diffusion.Herein,these factor...The development of a high-performing pseudocapacitor requires a comprehensive understanding of electrode materials from the aspects of electron transfer and electrolyte ion adsorption and diffusion.Herein,these factors are considered over the prototype TiO_(2),and a high pseudocapacitance is achieved via the introduction of various defects,i.e.,oxygen defect(V_(O))and co-doped defect(V_(O)+N_(O)).The study is based on joint explorations of first-principle calculations and the transfer matrix method.Relative to pristine TiO_(2)(300 F g^(-1)),defective TiO_(2) produces pseudocapacitance as high as 1700 F g^(-1).Moreover,defects induce small barriers for electron transmission caused by surface band bending.The climbing image nudged elastic band diffusion of H ions displays a much higher barrier in TiO_(2)-V_(O) than in TiO_(2)-V_(O)+N_(O).Such a result indicates easy H diffusion in the co-doped system.This work provides insights into the adsorption and diffusion of electrolyte ions and the influence of defects on electron transfer.The results are also significant for the design and optimization of electrode materials for the next generation of supercapacitors.展开更多
基金financially supported by the National Key Research and Development Program(2016YFB0901600)Tianjin City Distinguished Young Scholar Fund(17JCJQJC45100)+3 种基金the National Natural Science Foundation of China(21975136 and 21573117)Tianjin Key Research and Development Program(18ZXSZSF00060)the Open Funds from the National Engineering Lab for Mobile Source Emission Control Technology(NELMS2018A01)the project of Shenzhen Science,Technology and Innovation Committee(JCYJ20190808151603654)。
文摘The development of a high-performing pseudocapacitor requires a comprehensive understanding of electrode materials from the aspects of electron transfer and electrolyte ion adsorption and diffusion.Herein,these factors are considered over the prototype TiO_(2),and a high pseudocapacitance is achieved via the introduction of various defects,i.e.,oxygen defect(V_(O))and co-doped defect(V_(O)+N_(O)).The study is based on joint explorations of first-principle calculations and the transfer matrix method.Relative to pristine TiO_(2)(300 F g^(-1)),defective TiO_(2) produces pseudocapacitance as high as 1700 F g^(-1).Moreover,defects induce small barriers for electron transmission caused by surface band bending.The climbing image nudged elastic band diffusion of H ions displays a much higher barrier in TiO_(2)-V_(O) than in TiO_(2)-V_(O)+N_(O).Such a result indicates easy H diffusion in the co-doped system.This work provides insights into the adsorption and diffusion of electrolyte ions and the influence of defects on electron transfer.The results are also significant for the design and optimization of electrode materials for the next generation of supercapacitors.
