Sun Longhua, Gong Wenbin, Zhou Ji, Zhang Jiawen, Chen Chao, Meng Xiaodong, Han Xinyi, Mai Hairong, Bielawski Christopher W, Geng Jianxin
State Key Laboratory of Organic-Inorganic Composites, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, No. 15 North Third Ring East Road, Chaoyang District, Beijing 100029, China.
School of Physics and Energy, Xuzhou University of Technology, Xuzhou 221018, China.
J Colloid Interface Sci. 2024 Jan;653(Pt B):1694-1703. doi: 10.1016/j.jcis.2023.09.167. Epub 2023 Sep 30.
While transition metal nitrides (TMNs) are promising electrocatalysts, their widespread use is challenged by the complex synthetic methodology and a limited understanding of the underlying electrocatalytic mechanisms. Herein, we describe a novel synthesis of TMNs (including MoN, NbN, and ZrN) and explore their potential as electrocatalysts to affect sulfur cathode reactions. The TMNs were prepared in-situ using a process that simultaneously infuses nitrogen-doped porous graphitic carbon (designated as TMN@N-PGC). The methodology avoids the use of ammonia, which poses safety risks due to its flammability and toxicity. Analysis of the d-p hybridized orbitals formed between the transition metal ions and sulfur species revealed that the antibonding orbitals are empty. Thus, TMNs with more negative d-band centers exhibit stronger affinities towards polysulfides. NbN facilitated polysulfide conversion as well as LiS detachment, and thus featured a high electrocatalytic capability for promoting cathode kinetics. Lithium-sulfur (Li-S) batteries containing NbN@N-PGC exhibited the highest performance metrics in terms of specific capacity (1488 mA h g at 0.1 C), rate capacity (521 mA h g at 6 C), and cycling stability (603 mA h g at 0.5 C after 1300 cycles, corresponding a capacity decay of 0.030% per cycle). Li-S cells with high sulfur loadings also exhibit outstanding performance.
虽然过渡金属氮化物（TMNs）是很有前景的电催化剂，但其复杂的合成方法以及对潜在电催化机制的有限理解阻碍了它们的广泛应用。在此，我们描述了一种新型的TMNs（包括MoN、NbN和ZrN）合成方法，并探索了它们作为电催化剂影响硫阴极反应的潜力。通过同时注入氮掺杂多孔石墨碳（命名为TMN@N-PGC）的过程原位制备了TMNs。该方法避免了使用由于易燃性和毒性而存在安全风险的氨。对过渡金属离子与硫物种之间形成的d-p杂化轨道的分析表明，反键轨道是空的。因此，具有更负d带中心的TMNs对多硫化物表现出更强的亲和力。NbN促进了多硫化物的转化以及Li-S的脱附，因此具有促进阴极动力学的高电催化能力。含有NbN@N-PGC的锂硫（Li-S）电池在比容量（0.1 C时为1488 mA h g）、倍率容量（6 C时为521 mA h g）和循环稳定性（1300次循环后0.5 C时为603 mA h g，对应每循环容量衰减0.030%）方面表现出最高的性能指标。高硫负载的Li-S电池也表现出优异的性能。
