椰壳基硬炭作为钾离子电池负极材料的结构及其电化学性能  

Microstructures and electrochemical properties of coconut shell-based hard carbons as anode materials for potassium ion batteries

作　　者：黄滔 彭大春 陈醉 夏笑虹[1,2] 陈玉喜 刘洪波[1,2] HUANG Tao;PENG Da-chun;CHEN Zui;XIA Xiao-hong;CHEN Yu-xi;LIU Hong-bo(College of Material Science and Engineering,Hunan University,Changsha 410082,China;Hunan Province Key Laboratory for Advanced Carbon Materials Applied Technology,Hunan University,Changsha 410082,China)

机构地区：[1]湖南大学材料科学与工程学院,湖南长沙410082 [2]先进炭材料及应用技术湖南省重点实验室,湖南长沙410082

出　　处：《新型炭材料（中英文）》2022年第6期1125-1134,共10页New Carbon Materials

基　　金：国家自然科学基金(51772083,51402101);湖南省科技重大专项项目(2018GK1030).

摘　　要：生物质硬炭用作钾离子电池负极材料具有可逆容量高等特点,但较高的制备成本及较低的循环稳定性限制了其大规模应用。本文以废弃生物质椰壳为前驱体通过一步热解法制备椰壳基硬炭(CSHC)并作为钾离子电池负极材料。通过X射线衍射仪、N2吸脱附仪、拉曼光谱仪、扫描电子显微镜、透射电子显微镜和循环伏安法等考察了炭化温度对椰壳基硬炭微观结构及电化学性能的影响。结果表明,在1000°C下炭化所得的椰壳基硬炭具有合适的石墨微晶尺寸、孔隙结构及表面缺陷含量,表现出最佳的电化学性能:在30 mA·g^(−1)的电流密度下具有254 mAh·g^(−1)的可逆比容量及75%的首次库伦效率,在100 mA·g^(−1)的电流密度下循环100周后容量保持率为87.5%,循环400周后容量保持率达到了75%。说明所制备的椰壳基硬炭具有较高的可逆容量以及循环寿命,是一种电化学性能优异的储钾材料。Hard carbons have recently attracted wide interest as anode materials for potassium ion batteries(PIBs)because of their high reversible capacity.But,their high preparation cost and poor cycling stability prevent their practical use.Coconut shell-derived hard carbons(CSHCs)were prepared from waste biomass coconut shell using a one-step carbonization method,and were used as anode materials for potassium ion batteries.The effects of the carbonization temperature on the microstructures and electrochemical properties of the CSHCs were investigated by X-ray diffraction,nitrogen adsorption,Raman spectroscopy,scanning electron microscopy,transmission electron microscopy,and cyclic voltammetry,etc.Results indicate that the CSHC carbonized at 1000°C(CSHC-10)has a suitable graphite microcrystal size,pore structure and surface defect content,and has the best electrochemical performance.Specifically,it has a high reversible specific capacity of 254 mAh·g^(−1) at 30 mA·g^(−1) with an initial Coulombic efficiency of 75.0%,and the capacity retention rates are 87.5%after 100 cycles and 75.9%after 400 cycles at 100 mA·g^(−1),demonstrating its excellent potassium storage performance.

关 键 词：钾离子电池 椰壳基硬炭 炭化温度 微观结构 电化学性能 

分 类 号：TQ127.11[化学工程—无机化工]