Unlocking New Redox Activity in Alluaudite Cathodes through Compositional Design
Unlocking New Redox Activity in Alluaudite Cathodes through Compositional Design
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通过成分设计释放阿卢铝矿阴极的新氧化还原活性
DOI：
10.1021/acs.chemmater.2c00324
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发表时间：
2022
影响因子：
8.6
通讯作者：
Clément, Raphaële J.
中科院分区：
文献类型：
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作者：
Wu, Vincent C.;Giovine, Raynald;Foley, Emily E.;Finzel, Jordan;Balasubramanian, Mahalingam;Sebti, Elias;Mozur, Eve M.;Kwon, Andrew H.;Clément, Raphaële J.
钠（Na）离子导电聚阴离子结构是最有前途的正极材料之一，可以实现更可持续的钠基电池化学物质，以取代目前的锂基储能系统。采用冲积体结构的材料可以可逆地插入Na，磷酸盐和硫酸盐衍生物在用作Na离子阴极时表现出中等到高的容量。然而，在这种结构中主要只观察到Fe2+/3+氧化还原，这一事实阻碍了铝矾土阴极的发展。在此，我们证明了Mn2+/3+氧化还原对可以通过调整渗铝质化合物的组成来激活。具体来说，与磷酸盐和硫酸盐相比，钒酸盐化合物被用来提高电导率。Al取代也被用来缓冲Mn(III) o6八面体的Jahn-Teller扭曲，进一步促进电子转移和氧化还原过程。我们报道了一系列新的Na2Mn3-xAlx (VO4)3铝质阴极的合成，并采用同步加速器x射线衍射、固体核磁共振、扫描电子显微镜、密度泛函理论、x射线吸收光谱和磁强计来表征合成材料的结构、形貌、电子和磁性能。采用恒流循环技术、恒流间歇滴定技术和指数同步x射线衍射技术，研究了Na2Mn3-xAlx (VO4)3（x= 0,0.05, 0.2）中的电化学脱钠（插层）现象。虽然这些材料都具有氧化还原活性，但Al取代导致放电容量增加2倍以上。高电压Mn2+/3+氧化还原对的成功活化为冲积型na离子阴极开辟了新的组成空间。
Sodium (Na)-ion conducting polyanionic structures are among the most promising cathode materials to enable more sustainable Na-based battery chemistries to replace current Li-based energy storage systems. Materials adopting the alluaudite structure have been found to reversibly intercalate Na, with phosphate and sulfate derivatives exhibiting moderate to high capacities when used as Na-ion cathodes. However, the development of alluaudite cathodes has been hampered by the fact that largely only Fe2+/3+redox has been observed in this structure. Herein, we show that the Mn2+/3+redox couple can be activated through compositional tuning of alluaudite compounds. Specifically, vanadate compounds were explored to increase the electrical conductivity as compared to the phosphates and sulfates. Al substitution was also employed to buffer the Jahn–Teller distortions of Mn(III)O6octahedra, further facilitating electron transfer and redox processes. We report the synthesis of a series of new Na2Mn3–xAlx(VO4)3alluaudite cathodes and employ synchrotron X-ray diffraction, solid-state nuclear magnetic resonance, scanning electron microscopy, density functional theory, X-ray absorption spectroscopy, and magnetometry to characterize the structure, morphology, electronic, and magnetic properties of the as-synthesized materials. Electrochemical Na de(intercalation) in Na2Mn3–xAlx(VO4)3(x= 0, 0.05, 0.2) was probed through galvanostatic cycling, galvanostatic intermittent titration technique, andex situsynchrotron X-ray diffraction. While these materials are all redox active, Al substitution results in a more than 2-fold increase in discharge capacity. The successful activation of a higher voltage Mn2+/3+redox couple opens up a new compositional space for alluaudite-type Na-ion cathodes.
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影响因子：
8.6
作者：
Clement, Raphaele J.;Middlemiss, Derek S.;Grey, Clare P.
通讯作者：
Grey, Clare P.
DOI：
10.1515/znb-2019-0116
发表时间：
2019-08
期刊：
Zeitschrift für Naturforschung B
影响因子：
--
作者：
H. Ben Yahia;M. Shikano
通讯作者：
H. Ben Yahia;M. Shikano
影响因子：
6.6
作者：
Debasmita Dwibedi;P. W. Jaschin;Ritambhara Gond;P. Barpanda
通讯作者：
Debasmita Dwibedi;P. W. Jaschin;Ritambhara Gond;P. Barpanda
影响因子：
2.5
作者：
Ravel, B;Newville, M
通讯作者：
Newville, M
DOI：
10.1107/s2053229619007186
发表时间：
2019-05
期刊：
Acta crystallographica. Section C, Structural chemistry
影响因子：
--
作者：
Mohammed Hadouchi;A. Assani;M. Saadi;A. Lahmar;M. El Marssi;Lahcen El Ammari
通讯作者：
Mohammed Hadouchi;A. Assani;M. Saadi;A. Lahmar;M. El Marssi;Lahcen El Ammari