中国化学会第32届学术年会
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FexNiyS2@C复合材料的可控合成及储存钠性能研究
许永开 万延华 张继雨 张喜雪 陈卫华*

分会

第六分会:无机固态化学

摘要

FexNiyS2@C复合材料的可控合成及储存钠性能研究 许永开,万延华,张继雨,张喜雪,陈卫华,* 郑州大学化学学院,绿色催化中心,河南,郑州,450001 *Email: chenweih@zzu.edu.cn 地球上的锂元素资源分散且储量低、价格昂贵,而钠元素含量丰富、成本低,与锂同为碱金属元素,化学性质相似,因此钠离子电池(SIBs)可以作为锂离子电池(LIBs)的替代品之一[1-9]。由于硫化铁其理论容量高、成本较低且环境友好,被认为是钠离子电池最有应用前景的负极材料之一[1-5]。然而,其快速的容量衰减和较差的倍率性能限制了它的实际应用[2-6]。 我们通过调节材料中铁镍元素的比例,可控合成了三种铁镍双金属硫化物(FexNiyS2@C)。在电化学测试中, Fe0.78Ni0.22S2@C、Fe0.59Ni0.41S2@C和Fe0.42Ni0.58S2@C三种材料在0.1 A g-1的电流密度下,首周容量分别为707、674和602 mAh g-1(图1a),相应的库仑效率分别为85.5%、88.0%和87.2%。在0.1 A g-1下循环200周后(图1b),容量保持率分别为98.6%,77.5%和85.5%。图1a和1b的倍率性能图和循环性能图表明Fe:Ni的比例越高,材料的倍率性能越好,同时循环性能越好。此外,从不同倍率的充放电曲线可以看出Fe0.78Ni0.22S2@C材料具有较小的极化(图1c),显示出了优异的动力学特性。推测该材料优异的性能是由于Fe、Ni的协同作用改善了转化反应的可逆性,使双金属材料表现出优异的倍率性能和循环稳定性。 Fig. 1 FexNiyS2@C: a) Rate capability (0.1-10.0 A g-1); b) cycling performance. c) Charge/discharge curves of Fe0.78Ni0.22S2@C electrode at different current densities. 关键词:钠离子电池;双金属硫化物负极;转化反应;协同作用 致谢:感谢国家自然科学基金(No. 21771164, U1804129)和河南省中原千人计划对本项目的支持。 参考文献: [1] Chen, W.*; Zhang, X.; Mi, L.; Liu, C.; Zhang, J.; Cui, S.; Feng, X.; Cao, Y.*; Shen, C. Adv. Mater, 2019, 31, 1806664. [2] Yang, D.; Chen, W.*; Zhang, X.; Mi, L.; Liu, C.; Chen, L.; Guan, X.; Cao, Y.; Shen, C. J. Mater. Chem. A, 2019, 7, 19709–19718. [3] Song, K.; Liu, C.; Mi, L.; Chou, S.; Chen, W.*; Shen, C. Small, 2019, 1903194. [4] Chen, W.*; Qi, S.; Guan, L.; Liu, C.; Cui, S.; Shen, C.; Mi, L.J. Mater. Chem. A, 2017,5, 5332-5341 [5] Chen, W.*; Qi, S.; Yu, M.; Feng, X.; Cui, S.; Zhang, J.; Mi, L. Electrochimica Acta 230 (2017) 1–9 [6] Yang, K.; Zhang, X.; Song, K.; Zhang, J.; Liu, C.; Mi, L.; Wang, Y.; Chen, W.* Electrochimica Acta 2020, 135783. [7] Wang, T.; Yang, K.; Shi, J.; Zhou, S.; Mi, L.; Li, H.*; Chen, W.* J Energy Chem. 2020,46:71-7. [8] Zhang, J.; Song, K.; Mi, L.; Liu, C.; Feng, X.; Zhang, J.; Chen, W.*; Shen, C. J. Phys. Chem. Lett., 2020, 11, 1435−1442. [9] Zhao, L.; Tang, T.; Chen, W.*; Feng, X.; Mi, L.* Green Energy & Environment, 2018, 3, 277 Controllable Synthesis of FexNiyS2@C Composites and its Na Storage Properties Yongkai Xu, Yanhua Wan, Jiyu Zhang, Xixue Zhang, and Weihua Chen* Green Catalysis Center, College of Chemistry, Zhengzhou University, Zhengzhou, 450001 Lithium element resources on the earth are scattered, low in reserves, and expensive, while sodium is abundant in the earth and low in cost and both of them are alkali metal element and have similar chemical properties which can be used as a substitute for lithium ion batteries (LIBs). Due to its high theoretical capacity, low cost, and environmental friendliness, iron sulfide is considered to be one of the most promising anode materials for sodium ion batteries. However, its rapid capacity decay and poor rate performance limit its practical application. Three kinds of iron-nickel bimetal sulfides (FexNiyS2@C) were synthesized by controlling the proportion of iron-nickel elements in the material. In electrochemical tests, the capacities of Fe0.78Ni0.22S2@C, Fe0.59Ni0.41S2@C, and Fe0.42Ni0.58S2@C in the initial cycle were 707,674 and 602 mAh g-1(Fig. 1a), the corresponding coulombic efficiency is 85.5%, 88.0% and 87.2%, respectively. In addition, after 200 cycles at 0.1 A g-1(Fig. 1b), the capacity retentions are 98.6%, 77.5%, and 85.5%, respectively. Fig 1a and 1b shows that the larger ratio of Fe: Ni, the better rate performance of the material and the better cycle performance. In addition, it can be seen from the charge-discharge curves of different current densities that Fe0.78Ni0.22S2@C material has a smaller polarization (Fig. 1c), showing excellent kinetics characteristics. It is speculated that the excellent performance of this material is due to the synergistic effect of Fe and Ni, improved the reversibility of the conversion reaction, make the bimetallic materials exhibit excellent rate performance and cycle stability.

关键词

钠离子电池;双金属硫化物负极;转化反应;协同作用

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