The critical role of sodium content on structure, morphology and electrochemical performance of layered P2-type NaxNi0.167Co0.167Mn0.67O2 for sodium ion batteries
The critical role of sodium content on structure, morphology and electrochemical performance of layered P2-type NaxNi0.167Co0.167Mn0.67O2 for sodium ion batteries
复制标题
钠含量对钠离子电池层状P2型NaxNi0.167Co0.167Mn0.67O2结构、形貌和电化学性能的关键作用
DOI:
10.1016/jjpowsour.2017.07.057
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发表时间:
2017
影响因子:
9.2
通讯作者:
汪应玲
中科院分区:
文献类型:
--
作者:
包硕;罗绍华;王志远;王庆;郝爱民;张亚辉;汪应玲
P2-type manganese-based ternary transition metal oxides have triggered extensive researches as potential cathode materials for sodium ion batteries. However, these kinds of materials display the large difference in electrochemical performance with sodium content varying from 0.45 to 0.8, the relevant.investigations on effects of sodium content are insufficient. In this work, we synthesize a series of spherical P2-type cathode materials NaxNi0.167Co0.167Mn0.67O2 with different sodium content (x ¼ 0.45,0.55, 0.67, 0.8, 0.9, 1) and investigate the effects of sodium content on structure and electrochemical performance. The results reveal that NaxNi0.167Co0.167Mn0.67O2 (x ¼ 0.45, 0.55) consist of P2-phase and P3-phase, while NaxNi0.167Co0.167Mn0.67O2 (x ¼ 0.67, 0.8, 0.9, 1) exhibit pure P2-phase. Na0.45Ni0.167-.Co0.167Mn0.67O2 delivers an initial discharge capacity of 143 mAh g1, while a fast capacity decay is observed after 50 cycles. In comparison, Na0.67Ni0.167Co0.167Mn0.67O2 shows excellent cycling stability and rate performance. The significant difference in electrochemical performance is attributed to the initial sodium content, which leads to the existence of P3-phase. Moreover, higher sodium content promotes primary particles to grow larger and thicker, which is not favorable for the diffusion of Naþ. Generally,Na0.67Ni0.167Co0.167Mn0.67O2 is favored by suitable sodium content, offers excellent electrochemical performance in terms of capacity, rate performance and cycling stability.