Recently,CoCO3 has attracted enormous attention as anodes for lithium-ion batteries(LIBs),benefiting from its high theoretical capacity and simple synthesis.However,the modest electronic conductivity and structural in...Recently,CoCO3 has attracted enormous attention as anodes for lithium-ion batteries(LIBs),benefiting from its high theoretical capacity and simple synthesis.However,the modest electronic conductivity and structural instability over cycling hinder its wider applications.To well address the intrinsic issues,we explored a precipitantfree hydrothermal methodology for mass production of spindle-like CoCO3/reduced graphene oxide(S-CoCO3/rGO)toward advanced LIBs as a hybrid anode.The dimethylformamide plays a significant role of"two birds(i.e.,solvent and precipitant)with one stone"in the formation of the S-CoCO3/rGO,greatly improving its practical applicability.The purposeful introduction of rGO nanosheets as a two-dimensional flexible conductive network enhances the conductivity and stability of the S-CoCO3.It is the structural and compositional merits for LIBs that endow the S-CoCO3/rGO with remarkable lithium-storage performance in terms of enhanced interfacial storage capacity,high-rate reversible capacities(803 mAh·g-1 at 2.0 A·g-1)and long-duration capacity retention of 82.1%over 2000 consecutive cycles at 2.0 A·g-1.More significantly,the simple yet efficient avenue here promises enormous commercial prospect of the S-CoCO3/rGO in next-generation LIBs.展开更多
以葡萄糖作为碳源,通过简单的水热反应获得菱形碳包覆碳酸钴(Co CO3/C)复合材料,并研究了其作为锂离子电池负极材料的电化学性能.晶型和表面形貌通过X射线衍射(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)进行表征,用热重-差热分析...以葡萄糖作为碳源,通过简单的水热反应获得菱形碳包覆碳酸钴(Co CO3/C)复合材料,并研究了其作为锂离子电池负极材料的电化学性能.晶型和表面形貌通过X射线衍射(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)进行表征,用热重-差热分析法(TG-DTA)来测试Co CO3/C材料中碳的含量,用拉曼光谱分析无定型碳的存在.Barrett-Joyner-Halenda(BJH)则用来分析材料的孔径分布情况.实验表明,碳包覆不仅在Co CO3颗粒表面包覆了一层无定性碳,使得Co CO3材料在充放电过程中保持结构的稳定性,也形成了一些大约30 nm左右的介孔,这种孔的存在有助于电解液中离子的传输,从而提高材料的电化学性能.电极材料在0.90C(1.00C=450 m A g–1)倍率下进行循环测试,500次后的容量仍保持在539 m Ah g–1,显示出了较好的循环性能.当增加到3.00C倍率时Co CO3/C容量为130 m Ah g–1,再恢复到0.15C倍率时容量依然能够达到770m Ah g–1,表现出了Co CO3/C具有良好的稳定性.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.51772127 and 51772131)the Taishan Scholars(No.ts201712050)+3 种基金the Major Program of Shandong Province Natural Science Foundation(No.ZR2018ZB0317)the Natural Science Doctoral Foundation ofShandong Province(No.ZR2019BEM038)the Natural Science Doctoral Foundation of the University of Jinan(No.XBS1830)the Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong。
文摘Recently,CoCO3 has attracted enormous attention as anodes for lithium-ion batteries(LIBs),benefiting from its high theoretical capacity and simple synthesis.However,the modest electronic conductivity and structural instability over cycling hinder its wider applications.To well address the intrinsic issues,we explored a precipitantfree hydrothermal methodology for mass production of spindle-like CoCO3/reduced graphene oxide(S-CoCO3/rGO)toward advanced LIBs as a hybrid anode.The dimethylformamide plays a significant role of"two birds(i.e.,solvent and precipitant)with one stone"in the formation of the S-CoCO3/rGO,greatly improving its practical applicability.The purposeful introduction of rGO nanosheets as a two-dimensional flexible conductive network enhances the conductivity and stability of the S-CoCO3.It is the structural and compositional merits for LIBs that endow the S-CoCO3/rGO with remarkable lithium-storage performance in terms of enhanced interfacial storage capacity,high-rate reversible capacities(803 mAh·g-1 at 2.0 A·g-1)and long-duration capacity retention of 82.1%over 2000 consecutive cycles at 2.0 A·g-1.More significantly,the simple yet efficient avenue here promises enormous commercial prospect of the S-CoCO3/rGO in next-generation LIBs.
文摘以葡萄糖作为碳源,通过简单的水热反应获得菱形碳包覆碳酸钴(Co CO3/C)复合材料,并研究了其作为锂离子电池负极材料的电化学性能.晶型和表面形貌通过X射线衍射(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)进行表征,用热重-差热分析法(TG-DTA)来测试Co CO3/C材料中碳的含量,用拉曼光谱分析无定型碳的存在.Barrett-Joyner-Halenda(BJH)则用来分析材料的孔径分布情况.实验表明,碳包覆不仅在Co CO3颗粒表面包覆了一层无定性碳,使得Co CO3材料在充放电过程中保持结构的稳定性,也形成了一些大约30 nm左右的介孔,这种孔的存在有助于电解液中离子的传输,从而提高材料的电化学性能.电极材料在0.90C(1.00C=450 m A g–1)倍率下进行循环测试,500次后的容量仍保持在539 m Ah g–1,显示出了较好的循环性能.当增加到3.00C倍率时Co CO3/C容量为130 m Ah g–1,再恢复到0.15C倍率时容量依然能够达到770m Ah g–1,表现出了Co CO3/C具有良好的稳定性.
