采用活性炭吸附含Co2+,Mn2+,Ni2+和Li^+的乙酸盐混合溶液,辅以高温热处理制备了碳包覆LiNi1/3Co1/3Mn1/3O2(NCM@C).透射电子显微镜(TEM)观测结果表明,碳包覆层的厚度约为10 nm.电化学性能测试结果表明,在0.2C下首次...采用活性炭吸附含Co2+,Mn2+,Ni2+和Li^+的乙酸盐混合溶液,辅以高温热处理制备了碳包覆LiNi1/3Co1/3Mn1/3O2(NCM@C).透射电子显微镜(TEM)观测结果表明,碳包覆层的厚度约为10 nm.电化学性能测试结果表明,在0.2C下首次放电比容量为181 m A·h/g,首次充放电效率为90.7%;在20C倍率下,NCM@C仍具有78 m A·h/g的放电比容量,而采用溶胶凝胶法制备的Li Ni1/3Co1/3Mn1/3O2(NCM)的比容量仅为39 m A·h/g;NCM@C还表现出良好的循环稳定性,在0.2C倍率下循环50周容量保持率为88.1%,而NCM容量保持率仅为66.4%.展开更多
采用共沉淀法制备LiNi1/3Co1/3Mn1/3O2正极材料,并用聚苯胺(PANI)对材料进行表面包覆。通过XRD、SEM和透射电子显微镜(TEM),对材料的结构和形貌进行分析;采用恒流充放电、循环伏安和交流阻抗测试,研究包覆量对材料电化学性能的影响。当P...采用共沉淀法制备LiNi1/3Co1/3Mn1/3O2正极材料,并用聚苯胺(PANI)对材料进行表面包覆。通过XRD、SEM和透射电子显微镜(TEM),对材料的结构和形貌进行分析;采用恒流充放电、循环伏安和交流阻抗测试,研究包覆量对材料电化学性能的影响。当PANI包覆量为10%时,LiNi1/3Co1/3Mn1/3O2正极材料的电化学性能最好,以1 C在2.5~4.6 V循环,放电比容量为185.0 m Ah/g,比未包覆PANI的材料提高13.8%。展开更多
Herein,AgLi1/3Sn2/3O2 with delafossite structure was prepared by treating the layered compound Li2 SnO3 with molten AgN03 via ion exchange of Li^+for Ag^+.The structure characterization and the electrochemical perform...Herein,AgLi1/3Sn2/3O2 with delafossite structure was prepared by treating the layered compound Li2 SnO3 with molten AgN03 via ion exchange of Li^+for Ag^+.The structure characterization and the electrochemical performance of AgLi1/3Sn2/3O2 was thoroughly investigated.AgLi1/3Sn2/3O2 is found to possess stacking lamellar morphology,which means small electrochemical impedance and so facilitates charge transfer kinetics during the cycling.Compared with Li2 Sn03,due to the introducing of excellent electrical conductivity of silver,AgLi1/3Sn2/3O2 exhibits improved electrochemical performance in terms of capacity,cycling stability and coulombic efficiency.The results show AgLi1/3Sn2/3O2 presents favorable specific capacity of 339 mAh/g at current density of 200 mA/g after 50 cycles and initial coulombic efficiency of 96%.Exsitu XRD analysis revealed the reaction mechanism of AgLi1/3Sn2/3O2 as an anode for lithium ion batteries.展开更多
摘要采用活性炭吸附含Co2+,Mn2+,Ni2+和Li^+的乙酸盐混合溶液,辅以高温热处理制备了碳包覆LiNi1/3Co1/3Mn1/3O2(NCM@C).透射电子显微镜(TEM)观测结果表明,碳包覆层的厚度约为10 nm.电化学性能测试结果表明,在0.2C下首次放电比容量为181 m A·h/g,首次充放电效率为90.7%;在20C倍率下,NCM@C仍具有78 m A·h/g的放电比容量,而采用溶胶凝胶法制备的Li Ni1/3Co1/3Mn1/3O2(NCM)的比容量仅为39 m A·h/g;NCM@C还表现出良好的循环稳定性,在0.2C倍率下循环50周容量保持率为88.1%,而NCM容量保持率仅为66.4%.
摘要采用共沉淀法制备LiNi1/3Co1/3Mn1/3O2正极材料,并用聚苯胺(PANI)对材料进行表面包覆。通过XRD、SEM和透射电子显微镜(TEM),对材料的结构和形貌进行分析;采用恒流充放电、循环伏安和交流阻抗测试,研究包覆量对材料电化学性能的影响。当PANI包覆量为10%时,LiNi1/3Co1/3Mn1/3O2正极材料的电化学性能最好,以1 C在2.5~4.6 V循环,放电比容量为185.0 m Ah/g,比未包覆PANI的材料提高13.8%。
基金supported by Natural Science Foundation of Jiangsu Province of China (No.BK20170982)the National Natural Science Foundation of China(No.51601080)
摘要Herein,AgLi1/3Sn2/3O2 with delafossite structure was prepared by treating the layered compound Li2 SnO3 with molten AgN03 via ion exchange of Li^+for Ag^+.The structure characterization and the electrochemical performance of AgLi1/3Sn2/3O2 was thoroughly investigated.AgLi1/3Sn2/3O2 is found to possess stacking lamellar morphology,which means small electrochemical impedance and so facilitates charge transfer kinetics during the cycling.Compared with Li2 Sn03,due to the introducing of excellent electrical conductivity of silver,AgLi1/3Sn2/3O2 exhibits improved electrochemical performance in terms of capacity,cycling stability and coulombic efficiency.The results show AgLi1/3Sn2/3O2 presents favorable specific capacity of 339 mAh/g at current density of 200 mA/g after 50 cycles and initial coulombic efficiency of 96%.Exsitu XRD analysis revealed the reaction mechanism of AgLi1/3Sn2/3O2 as an anode for lithium ion batteries.