Tuning the electrochemical behavior of Co x Mn3-x sulfides by varying different Co/Mn ratios in supercapacitor
Tuning the electrochemical behavior of Co x Mn3-x sulfides by varying different Co/Mn ratios in supercapacitor
复制标题
DOI：
10.1007/s10853-017-0903-2
复制
发表时间：
2017-06-01
影响因子：
4.5
通讯作者：
Shu, Kangying
中科院分区：
文献类型：
--
作者：
Chen, Si;Chen, Haichao;Shu, Kangying
采用一步溶剂热法合成了一系列Co(X)Mn3-x硫化物(x=0，0.5，1，1.5，2，2.5，3)。通过改变不同的Co/Mn比，可以成功地调节Co-Mn硫化物的晶体结构、形貌和电化学性能。随着Co/Mn比的增加，电化学性能得到改善，这可以归因于Co离子和Mn离子之间的协同作用。Co2.5Mn0.5硫化物在电流密度为1Ag(-1)时表现出最高的比容量(289Cg(-1))、高的倍率性能(电流密度从1增加到50Ag(-1)时保持率为54.6%)和良好的循环稳定性(2000次循环后仍能保持95.1%的初始值)。以Co2.5Mn0.5硫化物为正极，RGO纳米片为负极的非对称电池，在功率密度为750W·kg~(-1)的条件下，具有22.3 Wh·kg~(-1)的高能量密度，5000次循环后的保持率达85%。
A series of Co (x) Mn3-x sulfides (x = 0, 0.5, 1, 1.5, 2, 2.5, and 3) were prepared by a facile one-step solvent thermal route. The crystal structure, morphology, and electrochemical performance of Co-Mn sulfide can be tuned successfully by varying different Co/Mn ratios. As the Co/Mn ratio increases, the electrochemical performance is improved, which can be ascribed to the synergistic effect between Co ions and Mn ions. Co2.5Mn0.5 sulfide exhibits the highest specific capacity (289 C g(-1) at a current density of 1 A g(-1)), together with great rate capability (54.6% retention when current density increases from 1 to 50 A g(-1)) and excellent cycling stability (95.1% of initial value can be retained after 2000 cycles). Moreover, an asymmetric device using Co2.5Mn0.5 sulfide as positive electrode, and RGO nanosheets as negative electrode shows high energy density of 22.3 Wh kg(-1) at a power density of 750 W kg(-1), as well as excellent cycling performance with 85% retention after 5000 cycles.