Manipulating the Electronic Structure of Nickel via Alloying with Iron: Toward High-Kinetics Sulfur Cathode for Na-S Batteries
Manipulating the Electronic Structure of Nickel via Alloying with Iron: Toward High-Kinetics Sulfur Cathode for Na-S Batteries
复制标题
通过铁合金化控制镍的电子结构：用于钠硫电池的高动力学硫阴极
DOI：
10.1021/acsnano.1c05778
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发表时间：
2021
期刊：
影响因子：
17.1
通讯作者：
Yu Yan
中科院分区：
文献类型：
--
作者：
Wang Lifeng;Wang Haiyun;Zhang Shipeng;Ren Naiqing;Wu Ying;Wu Liang;Zhou Xuefeng;Yao Yu;Wu Xiaojun;Yu Yan
室温Na-S（RT Na-S）电池由于转化动力学缓慢、穿梭效应严重等原因，导致电池倍率性能差、容量衰减快、库仑效率低等问题，严重阻碍了其实用化。因此，开发具有成本效益和高效的电催化剂来吸收可溶性长链多硫化钠（NaPSs）和加速NaPSs转化是至关重要的。在这里，催化剂开采首先进行密度泛函理论计算，这表明，合金化的Fe到Ni可以定制的电子结构，导致较低的反应能垒多硫化物转化。在此基础上，合理设计并制备了FeNi3 @空心多孔碳球（FeNi3@HC）作为室温Na-S电池的硫基质材料。正如预期的那样，S@FeNi3@HC阴极表现出优异的循环稳定性（在2 A g-1下500次循环后为591 mAh g-1）和出色的倍率性能（在5 A g-1下为383 mAh g-1）。我们的工作证明了一个有效的战略（即，富电子态的合金化策略）来设计用于RT Na-S电池的上级电催化剂。
The sluggish conversion kinetics and severe shuttle effect in room-temperature Na–S (RT Na–S) batteries cause knotty issues, such as poor rate performance, fast capacity decay as well as low Coulombic efficiency, which seriously impede their practical application. Therefore, exploiting cost-effective and efficient electrocatalysts for absorbing soluble long-chain sodium polysulfides (NaPSs) and expediting NaPSs conversion is of paramount importance. Herein, catalyst mining is first conducted by density functional theory calculations, which reveal that the alloying of Fe into Ni can tailor the electronic structure, leading to lower reaction energy barrier for polysulfide conversion. Based on this, FeNi3@hollow porous carbon spheres (FeNi3@HC) as a promising sulfur host for RT Na–S batteries are rationally designed and fabricated. As expected, the S@FeNi3@HC cathode exhibits an excellent cycling stability (591 mAh g–1after 500 cycles at 2 A g–1) and outstanding rate performance (383 mAh g–1at 5 A g–1). Our work demonstrates an effective strategy (i.e., alloying strategy with a rich electron state) to design superior electrocatalysts for RT Na–S batteries.