Precise carbon structure control by salt template for high performance sodium-ion storage  

作　　者：Dong Qiu Tengfei Cao Jun Zhang Si-Wei Zhang Dequn Zheng Haoliang Wu Wei Lv Feiyu Kang Quan-Hong Yang 

机构地区：[1]Shenzhen Key Laboratory for Graphene-Based Materials, Engineering Laboratory for Functionalized Carbon Materials, Graduate School at Shenzhen,Tsinghua University [2]Shenzhen Environmental Science and New Energy Technology Engineering Laboratory, Tsinghua-Berkeley Shenzhen Institute(TBSI), Tsinghua University [3]Nanoyang Group, School of Chemical Engineering and Technology, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , TianjinUniversity

出　　处：《Journal of Energy Chemistry》2019年第4期101-106,共6页能源化学（英文版）

基　　金：supported by the Guangdong Natural Science Funds for Distinguished Young Scholar (2017B030306006);the National Natural Science Foundation of China (Nos. 51772164, U1601206 and U1710256);the National Key Basic Research Program of China (2014CB932400);the Shenzhen Technical Plan Project (Nos. KQJSCX20160226191136, JCYJ20150529164918734 and JCYJ20170412171630020);the Shenzhen Environmental Science and New Energy Technology Engineering Laboratory (No. SDRC [2016]172)

摘　　要：Carbon materials are considered to be one of the most promising anode materials for sodium-ion batteries(SIBs),but the well-ordered graphitic structure limits the intercalation of sodium ions.Besides,the sluggish intercalation kinetics of sodium ions impedes the rate performance.Thus,the precise structure control of carbon materials is important to improve the battery performance.Herein,a 3D porous hard-soft composite carbon(3DHSC)was prepared using the NaCl as the template and phenolic resin and pitch as carbon precursors.The NaCl template restrains the growth of the graphite crystallite during the carbonization process,resulting in small graphitic domains with expanded interlayer spacing which is favorable for the sodium storage.Moreover,the Na Cl templates help to create abundant mesopores and macropores for fast sodium ion diffusion.The porous structure and the graphite crystalline structure can be precisely controlled by simply adjusting the mass ratio of Na Cl,and thus,the suitable structure can be prepared to reach high capacity and rate performance while keeping a relatively high Coulombic efficiency.Typically,a high reversible capacity(215 mA h g^(-1)at 0.05 A g^(-1)),an excellent rate capability(97 mA h g^(-1)at 5 A g^(-1)),and a high initial Coulombic efficiency(60%)are achieved.Carbon materials are considered to be one of the most promising anode materials for sodium-ion batteries(SIBs),but the well-ordered graphitic structure limits the intercalation of sodium ions.Besides,the sluggish intercalation kinetics of sodium ions impedes the rate performance.Thus,the precise structure control of carbon materials is important to improve the battery performance.Herein,a 3D porous hard-soft composite carbon(3DHSC)was prepared using the NaCl as the template and phenolic resin and pitch as carbon precursors.The NaCl template restrains the growth of the graphite crystallite during the carbonization process,resulting in small graphitic domains with expanded interlayer spacing which is favorable for the sodium storage.Moreover,the Na Cl templates help to create abundant mesopores and macropores for fast sodium ion diffusion.The porous structure and the graphite crystalline structure can be precisely controlled by simply adjusting the mass ratio of Na Cl,and thus,the suitable structure can be prepared to reach high capacity and rate performance while keeping a relatively high Coulombic efficiency.Typically,a high reversible capacity(215 mA h g^(-1)at 0.05 A g^(-1)),an excellent rate capability(97 mA h g^(-1)at 5 A g^(-1)),and a high initial Coulombic efficiency(60%)are achieved.

关 键 词：Sodium-ion batteries Salt-template 3D porous hard-soft composite carbon ANODE Electrochemical performance 

分 类 号：O4[理学—物理]