Fe-single-atom catalyst nanocages linked by bacterial cellulose-derived carbon nanofiber aerogel for Li-S batteries
Fe-single-atom catalyst nanocages linked by bacterial cellulose-derived carbon nanofiber aerogel for Li-S batteries
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DOI：
10.1016/j.cej.2023.146977
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发表时间：
2023-10
影响因子：
15.1
通讯作者：
Xueyan Lin;Wenyue Li;Vy T Nguyen;Shu Wang;Shize Yang;Lu Ma;Yonghua Du;Bin Wang;Z. Fan-Z.
中科院分区：
文献类型：
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作者：
Xueyan Lin;Wenyue Li;Vy T Nguyen;Shu Wang;Shize Yang;Lu Ma;Yonghua Du;Bin Wang;Z. Fan-Z.
锂硫电池（LSB）是实现高容量的一种很有前途的电池。尽管如此，其发展受到复杂的氧化还原过程的阻碍，动力学缓慢，特别是由此产生的多硫化锂（LiPS）穿梭效应。单原子催化剂（SACs），其原子利用率最大化，可以有效地化学吸附可溶性LiPS和加快硫化物转化反应动力学。在这里，我们报告了在硫阴极设计中引入Fe单金属原子催化剂（Fe-SAC）及其电催化效果。将Fe掺杂的ZIF-8纳米笼引入到廉价的生物质细菌纤维素中。热解过程将它们转化为具有通过碳纳米管网络连接的Fe-SAC官能化的N掺杂碳纳米笼（FeSA-NC@CBC）的气凝胶结构，其被用作支架以制造独立的和无粘合剂的硫阴极。我们进行了电化学测量，以揭示Fe-SAC功能，包括降低S8还原为液相LiPS和进一步还原为固相Li 2S 2/Li 2S的能垒，以及加速Li 2S 2/Li 2S成核和沉积，如我们的理论计算结果所证实的。得益于高活性Fe-SAC和三维导电网络的协同作用，硫化反应动力学得到改善，从而可以消除LiPS穿梭效应，从而提高LBS倍率性能和循环稳定性。因此，所制造的FeSA-NC@CBC复合阴极在2C下具有优异的倍率性能，可逆容量为840 mAh/g，在1C下500次循环后的长期循环稳定性为800 mAh/g。
Li-S battery (LSB) is promising for achieving high capacity. Still, its development is hindered by the complex redox process with sluggish kinetics and particularly the resulting lithium polysulfides (LiPS) shuttle effects. Single-atom catalysts (SACs), with their maximized atom utilization, could effectively chemisorb soluble LiPSs and expedite the sulfide conversion reaction kinetics. Here we report incorporating Fe single metal atom catalyst (Fe-SAC) in the sulfur cathode design and its electrocatalytic effects. Fe-doped ZIF-8 nanocages were introduced into a cheap biomass bacteria cellulose. A pyrolysis process converted them into an aerogel structure with Fe-SAC-functionalized N-doped carbon nanocages linked by a carbon nanofiber network (FeSA-NC@CBC), which was applied as a scaffold to fabricate freestanding and binder-free sulfur cathodes. We conducted electrochemical measurements to reveal Fe-SAC functions including lowering energy barriers for S8reduction to liquid-phase LiPSs and further to solid-phase Li2S2/Li2S and accelerating Li2S2/Li2S nucleation and deposition, as corroborated by our theoretical calculation results. Benefiting from the synergistic effects of highly active Fe-SAC and three-dimensional conductive network, the sulfide reaction kinetics is improved, which can diminish LiPS shuttle effects and therefore improve LBS rate performance and cycling stability. Accordingly, the fabricated FeSA-NC@CBC composite cathode delivers an excellent rate capability at 2C with a reversible capacity of 840 mAh/g and a long-term cyclic stability of 800 mAh/g at 1C after 500 cycles.