Lithium-ion batteries(LIBs)are considered to be indispensable in modern society.Major advances in LIBs depend on the development of new high-performance electrode materials,which requires a fundamental understanding o...Lithium-ion batteries(LIBs)are considered to be indispensable in modern society.Major advances in LIBs depend on the development of new high-performance electrode materials,which requires a fundamental understanding of their properties.First-principles calculations have become a powerful technique in developing new electrode materials for high-energy–den-sity LIBs in terms of predicting and interpreting the characteristics and behaviors of electrode materials,understanding the charge/discharge mechanisms at the atomic scale,delivering rational design strategies for electrode materials,etc.In this review,we present an overview of first-principles calculation methods and highlight their valuable role in contemporary research on LIB cathode materials.This overview focuses on three LIB cathode scenarios,which are divided by their cati-onic/anionic redox mechanisms.Then,representative examples of rational cathode design based on theoretical predictions are presented.Finally,we present a personal perspective on the current challenges and future directions of first-principles calculations in LIBs.展开更多
Nanostructured TiO2 has applications in solar cells, photocatalysts, and fast- charging, safe lithium ion batteries （LIBs）. To meet the demand of high-capacity and high-rate LIBs with TiO2-based anodes, it is import...Nanostructured TiO2 has applications in solar cells, photocatalysts, and fast- charging, safe lithium ion batteries （LIBs）. To meet the demand of high-capacity and high-rate LIBs with TiO2-based anodes, it is important to fine-tune the nanoarchitecture using a well-controlled synthesis approach. Herein, we report a new approach that involves epitaxial growth combined with topotactic conversion to synthesize a unique type of three-dimensional （3D） TiO2 nano- architecture that is assembled by well-oriented ultrathin nanobelts. The whole nanoarchitecture displays a 3D Chinese knot-like morphology; the core consists of robust perpendicular interwoven nanobelts and the shell is made of extended nanobelts. The nanobelts oriented in three perpendicular [001]A directions facilitate Li＋ penetration and diffusion. Abundant anatase/TiO2-B interfaces provide a large amount of interfacial pseudocapacitance. A high and stable capacity of 130 mA.h.g-1 was obtained after 3,000 cycles at 10 A·g-1 （50 C）, and the high-rate property of our material was greater than that of many recently reported high-rate TiO2 anodes. Our result provides, not only a novel synthesis strategy, but also a new type of 3D anatase TiO2 anode that may be useful in developing long-lasting and fast-charging batteries.展开更多
基金supported by the Beijing Natural Science Foundation(JQ19003,KZ202010005007 KZ201910005002)the National Natural Science Foundation of China(U19A2018,21875007,51802009 and 22075007).
文摘Lithium-ion batteries(LIBs)are considered to be indispensable in modern society.Major advances in LIBs depend on the development of new high-performance electrode materials,which requires a fundamental understanding of their properties.First-principles calculations have become a powerful technique in developing new electrode materials for high-energy–den-sity LIBs in terms of predicting and interpreting the characteristics and behaviors of electrode materials,understanding the charge/discharge mechanisms at the atomic scale,delivering rational design strategies for electrode materials,etc.In this review,we present an overview of first-principles calculation methods and highlight their valuable role in contemporary research on LIB cathode materials.This overview focuses on three LIB cathode scenarios,which are divided by their cati-onic/anionic redox mechanisms.Then,representative examples of rational cathode design based on theoretical predictions are presented.Finally,we present a personal perspective on the current challenges and future directions of first-principles calculations in LIBs.
基金This research was supported financially by the National Natural Science Foundation of China （NSFC） （Nos. 51672315, U1301242, 21271190, and 21403106）, the government of Guangzhou city for an international joint-project （No. 201704030020）, the Government of Guangdong Province for NSF （No. S2012020011113） and the provincial Ministry of Cooperative funded special funds （Nos. 2013A090100010, 2016B090932005, and 2015B090927002）, the Fundamental Research Funds for the Central Universities （No. 161gpy18）. The authors acknowledge Prof. Hong Jin Fan from Nanyang Technological University for helpful discussions.
文摘Nanostructured TiO2 has applications in solar cells, photocatalysts, and fast- charging, safe lithium ion batteries （LIBs）. To meet the demand of high-capacity and high-rate LIBs with TiO2-based anodes, it is important to fine-tune the nanoarchitecture using a well-controlled synthesis approach. Herein, we report a new approach that involves epitaxial growth combined with topotactic conversion to synthesize a unique type of three-dimensional （3D） TiO2 nano- architecture that is assembled by well-oriented ultrathin nanobelts. The whole nanoarchitecture displays a 3D Chinese knot-like morphology; the core consists of robust perpendicular interwoven nanobelts and the shell is made of extended nanobelts. The nanobelts oriented in three perpendicular [001]A directions facilitate Li＋ penetration and diffusion. Abundant anatase/TiO2-B interfaces provide a large amount of interfacial pseudocapacitance. A high and stable capacity of 130 mA.h.g-1 was obtained after 3,000 cycles at 10 A·g-1 （50 C）, and the high-rate property of our material was greater than that of many recently reported high-rate TiO2 anodes. Our result provides, not only a novel synthesis strategy, but also a new type of 3D anatase TiO2 anode that may be useful in developing long-lasting and fast-charging batteries.
