Realizing Fast Charge Diffusion in Oriented Iron Carbodiimide Structure for High-Rate Sodium-Ion Storage Performance
Realizing Fast Charge Diffusion in Oriented Iron Carbodiimide Structure for High-Rate Sodium-Ion Storage Performance
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DOI：
10.1021/acsnano.0c08314
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发表时间：
2021-04-12
期刊：
影响因子：
17.1
通讯作者：
Kajiyoshi, Koji
中科院分区：
文献类型：
--
作者：
Li, Jiayin;Wang, Rong;Kajiyoshi, Koji
碳二亚胺铁（FeNCN）是一类与普通过渡金属氧化物相比具有共价键结构的金属化合物。它可以为改进电池系统中电荷转移动力学的各种结构设计提供可能性。此外，这些可能性对促进钠离子电池倍率性能的提高仍有很高的期望。在碳基衬底上生长定向FeNCN晶体，沿[001]方向暴露{010}面（O-FeNCN/S）。它提供了高钠离子存储容量和卓越的速率能力（在0.2 ag（-1）时680 mAh g（-1）和在20 ag（-1）时360 mAh g(-1)），在典型的转化反应中表现出快速的电荷转移动力学和高赝电容贡献。这种高速率性能归因于FeNCN晶体的定向形貌。它沿[001]的取向在O-FeNCN/S的整个形貌中保持了na离子沿两个方向的优先扩散，支持了充放电过程中na离子的快速存储动力学。本研究可为今后金属碳二亚胺的合理结构设计提供思路，从而获得较高的电化学性能。
Iron carbodiimide (FeNCN) belongs to a type of metal compounds with a more covalent bonding structure compared to common transition metal oxides. It could provide possibilities for various structural designs with improved charge-transfer kinetics in battery systems. Moreover, these possibilities are still highly expected for promoting enhancement in rate performance of sodium (Na)-ion battery. Herein, oriented FeNCN crystallites were grown on the carbon-based substrate with exposed {010} faces along the [001] direction (O-FeNCN/S). It provides a high Na-ion storage capacity with excellent rate capability (680 mAh g(-1) at 0.2 A g(-1) and 360 mAh g(-1) at 20 A g(-1)), presenting rapid charge-transfer kinetics with high contribution of pseudocapacitance during a typical conversion reaction. This high rate performance is attributed to the oriented morphology of FeNCN crystallites. Its orientation along [001] maintains preferred Na-ion diffusion along the two directions in the entire morphology of O-FeNCN/S, supporting fast Na-ion storage kinetics during the charge/discharge process. This study could provide ideas toward the understanding of the rational structural design of metal carbodiimides for attaining high electrochemical performance in future.