分會

第六分會：無機(jī)固態(tài)化學(xué)

摘要

FexNiyS2@C復(fù)合材料的可控合成及儲存鈉性能研究 許永開，萬延華，張繼雨，張喜雪，陳衛(wèi)華,* 鄭州大學(xué)化學(xué)學(xué)院，綠色催化中心，河南，鄭州，450001 *Email: chenweih@zzu.edu.cn 地球上的鋰元素資源分散且儲量低、價格昂貴，而鈉元素含量豐富、成本低，與鋰同為堿金屬元素，化學(xué)性質(zhì)相似，因此鈉離子電池（SIBs）可以作為鋰離子電池（LIBs）的替代品之一[1-9]。由于硫化鐵其理論容量高、成本較低且環(huán)境友好，被認(rèn)為是鈉離子電池最有應(yīng)用前景的負(fù)極材料之一[1-5]。然而，其快速的容量衰減和較差的倍率性能限制了它的實(shí)際應(yīng)用[2-6]。 我們通過調(diào)節(jié)材料中鐵鎳元素的比例，可控合成了三種鐵鎳雙金屬硫化物（FexNiyS2@C）。在電化學(xué)測試中， Fe0.78Ni0.22S2@C、Fe0.59Ni0.41S2@C和Fe0.42Ni0.58S2@C三種材料在0.1 A g-1的電流密度下，首周容量分別為707、674和602 mAh g-1（圖1a），相應(yīng)的庫侖效率分別為85.5％、88.0％和87.2％。在0.1 A g-1下循環(huán)200周后（圖1b），容量保持率分別為98.6％，77.5％和85.5％。圖1a和1b的倍率性能圖和循環(huán)性能圖表明Fe:Ni的比例越高，材料的倍率性能越好，同時循環(huán)性能越好。此外，從不同倍率的充放電曲線可以看出Fe0.78Ni0.22S2@C材料具有較小的極化（圖1c），顯示出了優(yōu)異的動力學(xué)特性。推測該材料優(yōu)異的性能是由于Fe、Ni的協(xié)同作用改善了轉(zhuǎn)化反應(yīng)的可逆性，使雙金屬材料表現(xiàn)出優(yōu)異的倍率性能和循環(huán)穩(wěn)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. 關(guān)鍵詞：鈉離子電池；雙金屬硫化物負(fù)極；轉(zhuǎn)化反應(yīng)；協(xié)同作用 致謝：感謝國家自然科學(xué)基金(No. 21771164, U1804129)和河南省中原千人計劃對本項目的支持。 參考文獻(xiàn)： [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.

關(guān)鍵詞

鈉離子電池;雙金屬硫化物負(fù)極;轉(zhuǎn)化反應(yīng);協(xié)同作用

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