摘要
石墨基锂离子电池负极有限的理论容量和较慢的充电速度已不能满足需求,开发更高容量且兼具快充能力的锂离子电池负极材料成为研究重点。利用蔗糖与浓硫酸脱水反应得到初始硬碳(R-HC),并在NH_(3)/Ar气氛中退火,得到了氮掺杂的多孔硬碳(N-HC)。N-HC具有丰富的超微孔结构(孔径<0.75 nm)和较大的层间距(约为0.39 nm),使得锂离子在N-HC中的扩散系数能够达到9.0×10^(-8)cm^(2)·s^(-1)。在0.27 C和2.7 C(1 C=370 mA·g^(-1))条件下,N-HC负极经过680和1400次循环后容量分别为704.0 mA·h·g^(-1)和269.2 mA·h·g^(-1)。尽管其首次Coulomb效率还有待提高,N-HC负极已初步达到锂离子电池的快充性能要求。
The limited capacity and long charging time of graphite-based anodes for lithium-ion batteries cannot meet ever-growing demands.Developing anodes with a high capacity and a fast charging ability becomes a hotspot of the present research.Herein,an N-doped porous hard carbon(N-HC)was prepared via dehydration reaction of sucrose and sulfuric acid and subsequent annealing in NH_(3)/Ar.The diffusion coefficient of Li^(+)in N-HC reaches 9.0×10^(-8)cm^(2)·s^(-1)due to the rich ultra-micropore structure(i.e.,pore<size 0.75 nm)and the large interlayer spacing(i.e.,0.39 nm)in N-HC.The capacity of N-HC remains 704.0 mA·h·g^(–1)or 269.2 mA·h·g^(–1)after 680 or 1400 cycles at 0.27 C or 2.7 C(1 C=370 mA·g^(-1)).The N-HC electrode can meet the requirement of fast charging lithium-ion battery,while the initial Coulomb efficiency needs to be improved.
作者
李圣远
叶传仁
王伊哲
朱彦武
LI Shengyuan;YE Chuanren;WANG Yizhe;ZHU Yanwu(School of Chemistry and Materials Science,University of Science and Technology of China,Hefei 230026,China;Hefei National Research Center for Physical Sciences at the Microscale,Hefei 230026,China)
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2023年第9期2188-2196,共9页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金(51972299,52003265,52273234,52273239)。
关键词
锂离子电池
快充
硬碳
超微孔
高容量
lithium-ion battery
fast-charging
hard carbon
ultra-micropores
high capacity
